Abstracts from The World Federation for Laser Dentistry The 3rd Congress European Division June 9–11,2011 Rome,Italy

O-1. RADIO-CHEMIO-INDUCED ORAL MUCOSITIS AND LOW-LEVEL LASER THERAPY: A PRELIMINARY STUDY

Aim: Oral mucositis remains one of the most common and troubling side effects of antineoplastic radiation and drug therapy: its incidence in onco-hematological radio-chemiotreated patients is variable between 50 and 100% and its impact on this population is directly linked with the experience of intense pain causing reduction and modification of therapy regimens, decreased survival rates, and increased cost of care. The aim of this study is the preliminary evaluation of a low-level laser therapy (LLLT) protocol on healing process of oral mucositis and on pain and quality of life of patients experiencing this dramatic side effect.

Materials and methods: Patients were evaluated and treated at the Unità Operativa Semplice di Odontostomatologia e Chirurgia Maxillo-Facciale of the Hospital of Piacenza, where they were treated for primary disease with protocols of chemotherapy and/or radiotherapy. LLLT protocol was performed with a diode laser (808 nm–XD Smile, Fotona, Slovenia) on a 2 week six treatment schedule with power of 1 W and application of 1 min. Two blinded operators analyzed and scored the grading of mucositis [World Health Organization (WHO) classification] at each treatment and at 1 and 2 weeks after treatment. Patients were instructed to fill out questionnaires about their pain and capability of deglutition (Visual Analogue Scale and Numerical Rating Scale) and their quality of life.

Results: A relevant improvement in healing of oral mucositis, in terms of reduction of grading score, and of pain, deglutitory discomfort, and quality of life was recorded.

Conclusions: Results of this preliminary study are encouraging for the realization of larger studies focused on the application of LLLT protocols in management of radio-chemiotreated patients with oral mucositis.

O-2. SUPERPULSED LOW-LEVEL LASER THERAPY OF THE NEUROLOGICAL BURNING MOUTH SYNDROME: A PLACEBO-CONTROLLED STUDY

Background: Burning mouth syndrome (BMS) is a common condition whose nature is still obscure and controversial. It is characterized by burning sensations in the tongue or other oral sites, often without clinical or laboratory signs. According to its etiology, three BMS subtypes are recognized: BMS by local factors (lfBMS), BMS by systemic factors (sfBMS) and, the most frequent, neurological BMS (nBMS), in which symptoms are caused by central or peripheral neurological malfunctions affecting in particular the taste pathway. This placebo-controlled study investigates whether the biomodulating effect of superpulsed low-level laser therapy (LLLT) may enhance nBMS symptoms, thereby improving patients' quality of life.

Materials and methods: Among 160 patients affected by oral burnings attending the Oral Pathology Complex Operative Unit of the Department of Stomatological Sciences of Sapienza University of Rome, 77 were affected by nBMS. Forty-six patients, 32 female and 14 male, were randomly selected for the study. Thirty-eight (26 female, 12 male) received LLLT applications by a double diode superpulsed laser (Lumix2, Prodent, Verduno, CN, Italy) that emits contemporarily at 650 and 910 nm; with frequency of 50 kHz, fluence of 0.53 J/cm², for 15 min twice a week for 4 weeks (Study Group – SG); 8 patients (6 female, 2 male) received placebo cycles, by shielded irradiation (Control Group – CG). In both groups the irradiation area was on tongue sides over the taste pathway. Numeric Rating Scale (NRS) evaluation of maximum and minimum pain was registered before and after the treatment. Total NRS after treatment rates were deducted to the total pretreatment NRS values. The treatment was effective for differences over two points. Statistical analysis was performed by Kruskall–Wallis and Dunn's multiple comparison (MC) tests.

Results: No side effects were registered; all 46 patients completed therapy without interruption. In SG, 29 (76%) patients had benefits from the treatment with significant reduction of pain, whereas 9 (24%) patients had no relevant NRS differences. Only one CG patient had a positive effect after therapy. In none of the enrolled cases was there a worsening of the symptoms. Dunn's MC test resulted in significant (p<0.05) maximal NRS differences and the Kruskall–Wallis test showed the significance of the study (p<0.0001)

Conclusions: According to the results of this study, it is reasonable to suppose that superpulsed LLLT may play an important role in management of nBMS cases; however, more investigations are needed to clarify, by a greater number of cases, receiving both treatment and placebo, the efficacy of this LLLT application.

O-6. ERBIUM LASER IN ORAL SURGERY

Aim: The purpose of this paper is to show how the Erbium laser, universally known as equipment capable of working on the hard substance of the tooth (enamel, dentine, and cement), is also valid in bone surgery. In this report one can see how the osteotomy performed at the level of the mandible, for the removal of a large radicular cyst in relation to proximity to the mental nerve, or at the level of the upper jaw to perform a split crest, is highly selective. Much more can be done with this technique than with other methods such as Piezosurgery^® or rotary instruments.

Materials and methods: In the paper presented, an Erbium Laser was used with the following settings: 6W of power, 20 Hz of frequency, and a percentage of water and air, respectively, of 70% and 30%. The selected patients were subjected to preliminary radiological examination with CT DentSCAN and operated on using local anesthesia by infiltration with Articaina plus adrenaline 1/100,000. The bone cutting for the purposes was performed at power levels <3 W, with a sapphire tip mounted on the hand piece and used in noncontact mode.

Results: In patients treated with the Erbium laser, we obtained excellent clinical results and a quiet operative course, with a significant reduction of edema and excellent postoperative pain control. Upon removal of the sutures, on the 10th day, the tissue was fully refurbished and bone healing at 6 months appeared satisfactory.

Conclusions: We conclude that in the future we will see an increasing rise in the use of Erbium lasers in bone surgery due to its advantages.

O-7. MINIMAL INVASIVE APPROACH IN ORAL VASCULAR DISEASES USING LIGHT BOTH IN DIAGNOSIS AND THERAPY

Aim: The goal of this work is to reach a minimally invasive diagnostic–therapeutic protocol treatment of the oral cavity's vascular lesions with 980 nm diode laser, showing how the “light” plays a primary role in diagnostic and therapeutic procedures by transillumination and selective vascular photothermolysis.

Materials and methods: The study included 42 patients with vascular malformations, venous lakes, located on the lips or cheeks. The patients were divided into three groups. Two groups, 15 patients for each one, with one vascular lesion, and a third group that included 12 patients with a double vascular lesion. Before treatment, a transillumination of the lesions was performed. A 980 nm diode laser, Doctor Smile^™ Wiser 7 W manufactured by Lambda S.p.a., was used. A different laser setting was used for each group: the first one received a constant power mode and the second group a continuous mode at incremental powers. During the laser radiation, three different techniques were adopted for energy distribution: “lawn trimming movements,” circular movements, and speckling movements with the decrease/increase of the spot. Every technique was used on five patients. All lesions were treated until the photothermolysis was obtained. The third group was divided into three subgroups, according to the technique of irradiation, each one of four patients. Each of the patient's two lesions was treated with a different laser setting (constant vs incremental power mode).

Results: Therapeutic approach with incremental powers and preceded by laser analgesia, proved to be “less invasive” and, at the same time, more tolerated by patients. As for the techniques of irradiation, the lawn trimming technique was more painful than the circular movements technique, both with an average speed of 2 cm/sec. The spot's variation technique produced an intermediate index of pain compared with the other techniques mentioned previously, but it was more effective, especially in the small size lesions, and more manageable than the other techniques.

Conclusions: The use of a 980 nm diode laser, in continuous mode at incremental power with energy distribution appropriate patients techniques, allows the operator to adjust the laser dose on the basis of the effects observed in the lesion until photocoagulation, counting the patient's perception of pain level. Finally, thanks to transillumination, we can work in a safe mode and have a clearer idea of the peripheral vascular distribution network to the lesion and, at the same time, it is possible to perform a detailed verification of healing.

O-8. CLINICAL COMPARISON BETWEEN DIODE LASER (1064NM) AND SCALPEL INCISIONS IN ORAL SOFT TISSUE BIOPSY

Aim: The aim of this study was to compare the new diode laser (1064 nm) incision with conventional blade incision wounds after oral soft tissue biopsy in the terms of hemostasis, local anesthetic required, duration of incision, and postoperative pain.

Materials and methods: This study was conducted in the Oral and Maxillofacial Surgery Department of the college of Dentistry/University of Mosul and the Oral and Maxillofacial Surgery Department of Al-Salam Teaching Hospital between February 2010 and May 2010. Thirty patients were enrolled and divided in to two groups. Each group consisted of 15 patients. The first group included 15 patients requiring biopsy (based on their clinical indications for biopsy) in the oral cavity using surgical blade no. 15, the second group included 15 patients who needed biopsy in the oral cavity (based on their clinical indications for biopsy) using diode laser (Fox^TM, A.R.C. laser, Germany) wavelength 1064 nm with output power (3.5W) continuous wave (CW) in contact with the tip of bare fiber (200 μm). All the biopsies in the two groups were excisional and performed with the patient under local anesthesia, using infiltration technique.

Results: In comparison between the two groups, the amount of local anesthetic required in the second group (diode laser group 0.73 mL) was less than that required by the first group (blade incision group 1.6 mL) and showed statistically high significance at p value<0.05. The mean of the difference in the weight of the gauze before and after the operation in the second group (0.16 g) was less than the difference in the weight of the gauze in the first group (0.96 g), which showed a statistically high significance at p value<0.05. The mean of the duration for incision was statistically not significant between the two groups and the mean of pain score at the 1st postoperative day was statistically significant in the diode laser group in comparison with the blade incision group, but there was no statistical difference in the pain score level at the 3rd postoperative day between the two groups.

Conclusions: The use of diode (1064 nm) laser to perform oral biopsy has several advantages over the blade incisions, including that less local anesthesia is required, enhanced hemostasis (suturing after surgery was not necessary), and minimal postoperative pain and edema, with less inflammatory response.

O-9. LASER DEVICES IN THE MANAGEMENT OF BIPHOSPHONATE-RELATED OSTONECROSIS OF THE JAWS

Aim: The aim of this work was to evaluate, through a review of the recent literature and based on our experience, the capabilities of different lasers, both surgical and low power, in the management of bisphosphonate-related osteonecrosis of the jaws (BRONJ).

Materials and methods: Extractions may be necessary in patients in treatment with intravenous bisphosphonates, to whom a therapeutic holiday cannot be given. Low-level laser therapy (LLLT) can be applied before and after the extractions in order to facilitate the healing of the post-extractive socket. In those patients that already have developed a BRONJ, surgical removal can be easily performed using Er:YAG laser, which can perform a selective and atraumatic removal of necrotic bone. Moreover, LLLT can be used in the management of pain in those patients who cannot undergo surgical treatment or who have to delay it for different reasons.

Results: All the reviewed laser applications to BRONJ were shown to be effective and safe, if applied properly; however, establishing an appropriate treatment protocol is important to obtain success.

Conclusions: Management of BRONJ can be quite difficult; therefore, laser devices can be used, by surgical and/or biomodulatory effects, to improve clinical results regarding management of pain or advancement of postsurgical healing.

O-11. DENTAL SURGERY WITH HIGH-POWER DIODE LASERS

Aim: Diode laser surgery has been performed successfully since 1995, with different wavelengths, different modes of operation (continuous wave [CW], chopped, or pulsed mode), and various power parameters, mainly in the range of 2–10 W. Can the use of high power, short pulse durations and an increase of frequency improve the treatment procedures without generation of more side effects?

Materials and methods: Different surgical treatment procedures, such as frenectomy, incisions, and exposure of teeth, were performed with an Elexxion Claros^® diode laser, wavelength 810 nm. The power settings varied from 25 to 50 W, the pulse duration between 10 and 20 μs and the frequency used was 12,000–20,000 Hz.

Results and conclusions: As expected, all surgical procedures could be performed with the Elexxion Claros in high power mode as well as with all other diode lasers. The difference in using high power, very short pulses, and high frequency was a much shorter treatment time and an all- time effective coagulation. Because of the very short pulse durations, there was no higher level of carbonization and no increased effect of swelling or pain after surgery compared with powers of 2–8 W, if the surgeon has to change treatment modalities. The fiber has to be moved much more quickly to avoid thermal damage and carbonization. With a little routine, the treatment time could be reduced up to 50% without any further side effects using high power diode lasers.

O-12. THE LASER Er,CrYSGG AND THE CEREC 3D IN THE SYSTEMATIC CORRECTION OF GUMMY SMILE OVERCAST: FEW HOURS TO CHANGE A SMILE

Aim: In the restoration of the smile in patients with gummy smile, the use of porcelain veneers is often the elective treatment, but at the same time requires remodeling of the gums, the positioning according to azimuth gingival aesthetic parameters, the necessary bone remodelling, and the creation of new gingival width. A periodontal consolidated approach provides the crown lengthening to be able to perform such a procedure, resulting in stitches causing significant postoperative discomfort and a delay of 100 days before we can begin the prosthetic therapy. The author's aim is to test a new surgical approach developed by himself, which involves a guided surgery using laser light in flapless mode, and then an immediate prosthetic treatment using CAD/CAM system for the preparation of porcelain veneers.

Materials and methods: This study used a laser Er,CrYSGG wavelength 2.78 μm, pulse energy 300 mJ, pulse length 140 μs, frequency 20–30 Hz, fiber optic Ø 320–400 μm, power range 0.75–2.5 W, beam incidence 0, 45, and 90 degres. CEREC 3D CAD/CAM system with the drive milling and feldspathic ceramic blocks and disilicate blocks was used. Five patients were treated after a careful study design and functional throrough a wax-up of teeth and gums. Then, a specific surgical template was made and a clinical crown lengthening and bone remodeling in exclusive laser flapless surgery was performed. Afterwards the teeth were prepared by high-speed drills for porcelain veneers. Thus, the teeth were recorded by the optical impression CAD/CAM system and the veeners were prepared by the milling machine. Two dental technicians were dedicated to the characterization and staining of the veeners, and a few hours after surgery veneers were cemented permanently.

Results: No patient felt pain, and postoperative edema was greatly reduced compared with when traditional techniques were used. Controls at 5 years showed a stability of tissue, no inflammatory disease, and great patient satisfaction.

Conclusions: The author believes that the proper use of the Er,CrYSGG laser and the CEREC 3D system can exclusively create the complete smile, with reconstruction taking only a few hours, and with stable and predictable results.

O-13. USE OF DENTAL LASERS IN THE TREATMENT OF HERPEX SIMPLEX VIRUS INFECTION

Aim: The herpes simplex virus (HSV)-1 is characterized by recurrent infection, which is often manifested by the clinical appearance of lesions on the upper and lower lips, nose, chin, and cheek, and inside the mouth. It occurs in 20–40% of the population. Individuals may experience recurrences in more than one location, mostly in the oral and perioral region. Reactivation begins with a prodrome of pain, burning, or itching where a lesion will appear, followed by the appearance of vesicular lesions. After several days, the vesicles rupture and coalesce, forming ulcerated plaques. This plaque resolves in the following days. The whole process takes ∼10–14 days. After lesions heal, the virus returns to latency. The most common treatment for recurrent herpes labialis (RHL) is based on antiviral compounds, such as acyclovir or valacyclovir. However, the intermittent administration of acyclovir can promote drug resistance. It also only yields a good response if applied before the onset of the vesicles. The present study describes the results of 10 clinical cases in which two types of laser therapy were used to treat RHL.

Materials and methods: Ten clinical reports are presented with the diode laser (810 nm) and the Er,Cr:YSGG in order to explain the ability to use these for the treatment of RHL. A visual analogue scale (VAS) was used to determine the initial and post-treatment reduction and to compare the two types of lasers.

Results: The effects of laser treatment on pain and inflammation modulation in herpes labialis lesions revealed good results, such as lower levels of inflammation, providing a more comfortable condition for patients. They were followed up monthly and did not show any signs of recurrence in 6 months.

Conclusions: The present clinical case reports have shown the efficacy of the two types of lasers on the treatment of herpes labialis. All patients considered the technique painless and comfortable. The healing process was favorable, and there was no recurrence of the lesions during the 6 month follow-up. Further studies, including double-blind, randomized clinical trials with a greater number of patients, are necessary to reach an established protocol.

O-14. USE OF LASER-ASSISTED SURGERY IN ORTHODONTIC TREATMENT OF THE ADULT PATIENT: CASE REPORT

Aim: The aim of this work was to present a new technique of flap surgical corticotomy on the alveolar process of the maxilla in adult patients undergoing orthodontic treatment through the use of Erbium and diode laser.

Materials and methods: The selected patients had dental malocclusion with transverse discrepancy of the arches, and complained of temporomandibular disorders with masticatory muscle pain. These patients underwent electromyographic investigation, which also showed an occlusal instability, according to the school of Ferrario and Sforza, State University of Milan, Department of Human Morphology and Biomedical Sciences. It was decided to seek a new balance of both neuromuscular order and occlusion, through the expansion of the superior arch achieved by orthodontic treatment and surgical corticotomy of the alveolar process of the maxilla (corticotomy-assisted expansion [CAE]). The corticotomy operation was performed with a mucosal flap from the oral vestibulum of the maxilla and skeletonization of the underlying alveolar process. Corticotomies were then performed by vertical groove at all interdental spaces. The soft tissue was treated with 980 nm diode laser (Doctor Smile Lambda Scientifica) and a 300 μm fiber in pulsed mode (6 W, repetition rate T on 20 ms T off 50 ms). The alveolar corticotomy was performed with a 2940 nm Erbium laser (Pluser Lambda Scientifica) and a 400 μm tip, 20 Hz frequency, 2.5 W power, 90% air 20% water. The rationale for use of lasers in comparison with other techniques such as piezoelectric surgery or surgical drills is to control the bleeding of soft tissues, decontaminate the operative field, save cortical bone, reduce inflammation, and biostimulate the reshaped tissue during the orthodontic movement.

Results: In the treated patients, the postoperative course was characterized by localized soft tissue swelling of the face for 2 days. The pain valutation by visual analogue scale (VAS), 2 days after the operation, showed the following results: one patient with a score of 3, three patients with a score of 2. In all patients, there was a growing orthodontic mobility thanks to an effective corticotomy. Orthodontic surgery performed with Erbium and diode lasers has proved to be an effective and alternative technique to the traditional methods based on mechanical instruments.

Conclusions: These new technologies offer a higher speed of execution, an increased agility in shaping incisions, and saving of tissues, resulting in minor postsurgical trauma and greater compliance by patients.

O-15. 810 NM DIODE LASER APPLICATIONS IN ORAL SURGERY COMPARED WITH TRADITIONAL TECHNIQUES

Aim: The aim of this clinical study was to evaluate the reliability and efficacy of an 810 nm diode laser in the treatment of soft tissue lesions localized in the oral cavity. The authors wanted to compare the traditional surgical management of those lesions with the 810 nm diode laser treatment, in particular regarding postoperative pain reduction and healing time.

Materials and methods: Between 2006 and 2010, at Sandro Pertini Hospital in Rome, 120 oral soft tissues lesions were examined and catalogued: 25 were localized on the gingiva, 57 on the buccal mucosa, 22 on the tongue, and 16 on the lips. Ninety of these lesions were treated by 810 nm diode laser (2.5–3 W with 200–300 m fibers in continuous wave) whereas 30 were treated by traditional scalpel technique. Immediately after the treatment, all the specimens were fixed in 10% buffered formalin solution for the histological final diagnosis. Pain evaluation was performed by the numeric rating scale (NRS) and the healing was evaluated at 1, 2, and 4 weeks and at 3 months.

Results: In examined lesions, the laser treatment was almost always performed without local anaesthesia and always without suture. The diode laser is highly absorbed by pigmented tissues with hemoglobin and melanin. For this reason, during surgical phases, the action of vaporization and incision is well controlled because of the absence of bleeding, which is guaranteed by coagulation and hemostasis. All the laser-treated lesions healed by second intention and quite rapidly in comparison with scalpel controls: the tongue wounds recovered in a median of 10 days, and the other areas appeared healthy after ∼3–4 weeks. NRS ratings were always lower in the laser group.

Conclusions: The benefits of diode laser treatment concern reduced bleeding during surgery with consequent reduced operating time and rapid postoperative hemostasis, thus eliminating the need for sutures and anesthetics. Lower pain and better healing are additional benefits in laser- treated lesions. These advantages make this technique particularly useful for young patients and for patients with systemic disorders.

O-17. BIPHOSPHONATE-RELATED OSTEONECROSIS OF JAW: A LOW SURGICAL IMPACT THROUGH NONLINEAR LBO LASER AND ULTRAWEAK MULTIFREQUENCY COMPLEX MAGNETIC FIELDS

Aim: LBO 532 nm nonlinear laser and complex magnetic fields (CMFs) together have demonstrated the capability to repair biphosphonate-related osteonecrosis of jaw (BRONJ) at the same time, both in the maxilla and the jaw, using a specific surgical protocol, without large surgical bone excision. Nonlinear physical devices exert a modulator effect on the biomolecular pathways of tissue repair, play a significant antibacterial role, and have a very low surgical impact. We obtained bone healing with very little dimensional loss. We analyzed this very complex clinical case: a female patient 80 years old. After 10 years in medical therapy, first with biphosphonates by injection, then with oral drugs, she had the clinical and radiological signs of bisphosphonate-related osteonecrosis, both in the maxilla and the jaw.

Materials and methods: A 532 nm LBO (lithium triborate LiB₃O₅) nonlinear laser therapy was used to obtain a microphotoablation, photobiomodulation, and a high decontaminant effect; all with different physical parameters of laser emission. There were six applications, one every 3 days, of CMFs, to obtain an accelerated and qualitatively improved neo-osteomorphogenesis with magneto electric therapy (MET) 30 min prog A–30 min prog C 100-delivery therapy-antibiotic therapy with amoxicillin 1 g twice a day for 2 weeks, and rinse with clorhexidine 0.2 three times a day.

Results and conclusions: We saw a complete repair of both the BRONJ injuries in 8 months after physical therapy, and without large surgical excision. At the same time we had spontaneous repair of the parodontal injury without root canal re-treatment of 33. The quality of three-dimensional bone repair of all the injuries was interesting. This case suggests that physical devices could support surgical therapy for BRONJ.

O-18. ONE DAY AT A CLINIC FOR LASER SUPPORTED DENTISTRY

Aim: Clinical photographs and films are presented to underline the multiple benefits of evidence-based laser treatment in dentistry.

Materials and methods: Treatment protocols based on science in the field of laser dentistry are frequently used in our clinic. In 9 treatments out of 10 we find indications for laser-supported dentistry that the patient will benefit from.

Results: Using different wavelengths, the laser even promotes selective removal of infected/decayed hard and soft tissue as well as providing improved prognosis compared with conventional treatment methods alone.

O-19. INFLUENCE OF THE EMISSION PARAMETER OF Er,Cr:YSGG LASER ON DENTINE BONDING: COMPARATIVE STUDY

Aim: The aim of this study was to measure and compare the differences in bond strength values obtained by shear strength test between drilled dentin and dentin irradiated with Er,Cr:YSGG laser, with two different hand pieces, and two different energies per pulse for each one, always using the same self-etching adhesive system components based on 4-MET.

Materials and methods: Seventy-five molars extracted and divided in two halves (150 samples of dentin), were randomized into five groups. The first group served as control with standardized bur cut, groups two and three were conditioned with Er,Cr:YSGG turbopiece (group 2: 66 mJ pp, 30 Hz, 8.8 J/cm² and group 3: 200 mJ pp, 10 Hz, 26.6 J/cm² ) and groups four and five, with Er,Cr:YSGG laser gold piece (group 4: 123 mJ pp, 30 Hz, 8.2 J/cm² and group 5: 382 mJ pp, 10 Hz, 25.46 J/cm²). All samples were treated with a self-etching adhesive system G-BOND (GC Corporation) and Gradia Direct Flow and Gradia Direct (GC Corporation) as the resin composite, and tested with a specific device for shear bond strength test.

Results: The specimens were submitted to statistical analysis using descriptive statistic and Student t test for independent samples. No statistical significances were observed. The mean values in MPa were 18.56 for the control group, 15.87 for group 2, 15.64 for group 3, 18.53 for group 4, and 16.13 for group 5.

Conclusions: Dentin irradiated with Er,Cr:YSGG laser using low density energy per pulse shows similar values, in terms of bond strength resistance, as dentin drilled, when 4-MET self-etching is used. No statistical significance between the study groups was observed.

O-20. FULL LASER-PREP CEREC INLAYS, FIRST RESULTS, RE-LIVE-FILM PRESENTATION

First, the biophysical interaction of an Er:YAG laser preparation and the possibilities in combination with the CEREC 3D will be discussed. The clinical steps, difficulties, and limitations will be shown. Then they awill show an English synchronised film presentation of two Er:YAG laser preps with chairside ceramic fillings. It will be shown, that there is a very good option of doing a full laser prep for CEREC inlays. In terms of clinical parameters, it is possible to have a chairside CEREC inlay in comparable time and with comparable efficiency. Indications, advantages, disadvantages, scan or impression, and time needed will be shown. Also, first results of different studies will be given.

O-21. ORAL SOFT TISSUE WOUND HEALING AFTER LASER SURGERY WITH OR WITHOUT POOL OF AMINO ACIDS AND SODIUM HYALURONATE: CLINICAL STUDY

Aim: The aim of this study was to compare oral soft tissue wound healing after laser surgery with and without use of a compound gel containing amino acids and sodium hyaluronate (Aminogam®, Errekappa, Italy).

Materials and methods: Excisional biopsy of an oral benign lesion (e.g., fibroma, HPV lesion, mucocele) was performed in oral soft tissues using KTP laser (SmartLite®, DEKA, Italy, 532 nm) on patients who then were divided into two groups. In group A, after the laser surgery, a compound gel containing four amino acids and sodium hyaluronate (Aminogam®) was administered; in group B (control), no topical substances were applied. Chlorhexidine spray was administered 3 times a day in each group, for the whole healing period. Furthermore, each patient received a numeric rating scale (NRS) paper, in order to assign a number to the pain suffered during the postoperative period. Moreover, using a millimetrated grid as a benchmark and a computer software (Photoshop®), it was possible to measure the area of the surgical wound, after the surgery and at 7 day periods. Comparing the two measures, it was possible to calculate a value of percentage healing index (PHI) indicating recovery extension in the time period.

Results: The cases treated with the compound gel (group A) showed an average PHI higher than group B. NRS pain scaled did not show significant differences between the two groups.

Conclusions: Although hyaluronic acid gel did not cause less pain during the first week after surgery, it promoted a better healing of the laser wound, definitely reducing the area of the lesion in the 1st week after surgery.

O-22. THE BEST FROM TWO WORLDS: THE LASERHF SYSTEM

Aim: We are attempting to ask whether a combined device of laser and radiofrequency is useful in oral surgical applications. Because both technologies are proven and valuable tools in dental soft tissue management, the combination will offer advanced use, giving benefits to the patient as well as to the dentist.

Materials and methods: We introduce the first worldwide combination device, with a 6 W at 980 nm laser for use in periodontics, endodontics, implantology, and oral surgery ; a 100 mW at 660 nm laser for low-level laser therapy (LLLT) and photodynamic therapy (PDT), plus a radiofrequency source (monopolar/bipolar) with 50 W at 2.2 MHz for surgical applications.

Results: Lasers providing an output power of <2–3 W are considered to be helpful tools in many applications such as endodontics, periodontics, implantology, LLLT, and PDT, and many scientific and clinical studies have shown the ability and effectiveness. However, in the field of oral surgery, the use of a laser often is limited. For surgical procedures such as deep cutting and coagulating of tissues well supplied with blood or dense textured, sometimes a laser power of >5 W, even >10 W is recommended. In such cases, the laser operation mostly is accompanied by a large amount of heat, which may lead to serious damage in the adjacent tissues, but also may damage the laser fibers. Then, the high-powered laser light may be not only beneficiary but also may raise unnecessary and unwanted side effects. Considering the enormous spectrum in dental soft tissue treatments, the LaserHF concept is the logical result of laser applications in periodontics, endodontics, implantology, LLLT, and PDT, plus an excellent tool for surgical applications with its radiofrequency source.

O-23. OPTIMIZING AESTHETIC DENTISTRY WITH A DIODE-LASER DEVICE (808 NM)

Aim: In a treatment plan in the field of aesthetic dentistry, every essential inherent element must be taken into consideration when preparing.

Materials and methods: Analysis should include facial, dental–labial, dental, gingival, and phonetic details as well as the patient's capacity for compliance.

Results: As we run through some different cases, we will show how to put such an analysis into practice in order to achieve the best overall result for each particular patient, in accordance, naturally, with the patient's own personal preferences.

Conclusions: We hope to demonstrate the advantages that can be gained from the use of a diode-laser device, which will help us optimize our clinical steps and guarantee the patient's satisfaction more than any other equipment currently in use.

O-24. REMOVAL OF A TRAUMATIC FIBROMA IN A 4-YEAR-OLD CHILD USING AN Er:YAG LASER LITE TOUCH: A CASE REPORT

Aim: The traumatic fibroma is a benign proliferation that is common in children and occurs as a response to local irritation. The most frequent localizations of these lesions include the lower lip and the cheek mucosa. The classical surgical treatment requires anesthesia, precise cutting, hemostasis, and sutures and could be problematic for children. Revolutionary advances in Er:YAG laser technology have led to expanded laser applications in oral surgery, and a large spectrum of oral conditions in the pediatric population can be successfully treated.

Materials and methods: This report describes the case of a 4-year-old boy with a nodular lesion that involved the lower lip mucosa. Laser excisional biopsy using an Er:YAG laser LiteTouch™ (Syneron Dental Laser) was performed. Only topical anesthesia was applied to the fibroma and adjacent mucosa, and no infiltration was used.

Results: No pain medication or antibiotics were required after surgery, and wound healing was excellent and achieved rapidly without sutures. The oral pathology report confirmed the presurgical clinical diagnosis of traumatic fibroma. No relapse was observed a year after the surgery.

Conclusions: Laser excisional biopsy is a modern approach for treating oral soft tissue lesions, and should be considered as an alternative to conventional scalpel surgery. Er:YAG laser surgery in the pediatric population poses a unique advantage for the clinician on a variety of levels: remote application, precise cutting, hemostasis, low cicatrization, and reduced postoperative pain and swelling.

O-27. LASER AND SPECIAL CARE DENTISTRY: AN OPEN WINDOW

Aim: Special care dentistry is always searching for new operating protocols facilitating the gain of therapeutic goals in a vulnerable population that often presents difficulties of approach and a high risk of complications during and after the treatments. In this process focused on a continuous improvement of quality of clinical and therapeutic treatment, hospitals should well know the opportunities that technological innovation offers to increase the capacity to treat different oro-maxillo-facial diseases, often associated with systemic disorders further complicating the therapeutic process. The aim of this work is to focus attention on the usefulness of laser technology in special care dentistry and the increase of the application of different wavelengths to treat “special needs” patients.

Materials and methods: Most patients of the Unità Operativa di Odontostomatologia e Chirurgia maxillo-facciale “Disabilità e progetti speciali” of the Hospital of Piacenza are carriers of congenital and acquired disorders (cognitive, physical, psychiatric, and medical) requiring “special care” in special locations and with trained operators, also with the use of specific tools. The availability of different laser wavelengths (CO₂, diode, Er:YAG), which have demonstrated great efficacy in surgical, conservative, and prosthetic dentistry, offers the possibility to treat a large part of pathological oral disease in this vulnerable population (motility and behavioral disease, immune and bleeding disorders, side effects of head and neck chemio-radiotherapy).

Results: Laser-assisted minimally invasive techniques significantly improved therapeutic results, particularly gaining greater cooperation of patients with behavioral problems, significantly reducing complications in patients at risk of infection and bleeding, and improving the quality of life in patients treated for head and neck cancer.

Conclusions: Because of its versatility in all fields of applications, laser-assisted dentistry is a valid option complementary to conventional dental techniques. Hospitals and clinics able to introduce this technique and train operators could offer a better therapeutic option to special care patients.

O-30. MICROLEAKAGE IN CLASS V CAVITIES WITH SELF-ETCHING ADHESIVE SYSTEM AND CONVENTIONAL ROTATORY OR LASER Er,Cr:YSGG AT DIFFERENT PARAMETERS

Objective: The purpose of this study was to analyze microleakage in Class V cavity preparation, contrasting effects of various techniques in three groups: (1) using the burr, (2) Er;Cr:YSGG laser preparation with high energy (4W, 30 Hz, 50% water 50% air), and (3) lower energy (1.5 W, 30 Hz, 30% water 30% air), at enamel and cement/dentin walls in permanent teeth.

Background: Several studies reported microleakage around composite restorations when cavity preparation is performed or treated by Er;Cr:YSGG laser. As there is no presence of hybrid layer when using laser, the use of a chemical bonding (4-META) adhesive system is advantageous. In addition, when it is used together with the laser energy, minimal gaps and microleakage should occur.

Results: Lower energy laser used for preparation showed significant differences in enamel and dentin. For group 3, the microleakage in the enamel was less, whereas group 1, treated with the turbine, showed less microleakage at the dentin level. Group 2 showed the highest microleakage at the dentin/cement level.

Conclusions: Burr preparation gives the lowest microleakage at the cement/dentin level, whereas Er;Cr:YSGG laser at lower power obtains the lowest microleakage at enamel. High energy settings produce worse results in terms of microleakage.

O-31. MINIMALLY INVASIVE PEDIATRIC DENTISTRY

Aim: Minimally invasive dentistry has become more prevalent in recent years with the development of relevant treatment techniques. Especially in pediatric dentistry, painless, nontraumatizing techniques improve the compliance with and acceptance of dental treatments by very young patients. Here, we investigate the use of laser therapy as a step toward successful minimally invasive treatment procedures for children.

Materials and methods: Different minimally invasive treatments were analyzed in pediatric restorative dentistry and oral surgery and compared with conventional treatments: In preventive therapy, we compared fissure sealing using an Er,Cr:YSGG laser (2780 nm) with a conventional technique using a polishing brush; in restorative dentistry, we compared cavity preparation using an Er,Cr:YSGG laser with a conventional bur or high-speed drill treatment. The laser parameters varied between 1.5–6 W, 20–30 Hz, 140 μs for enamel and 3.5–4 W, 30–35 Hz, 140 μs for dentin. In oral surgery, we compared surgical procedures such as frenectomy, treatment of pericoronitis, and uncovering of impacted teeth using an Er,Cr:YSGG laser and a diode laser (810 nm) with conventional scalpel surgery. The settings for the Er,Cr:YSGG laser were 1.5–2.0 W, 30 Hz, 700 μs; for the diode laser 2–3 W; continuous wave (CW) mode was used. The laser treatment procedures followed the Laserkids® (2008) guidelines for laser-assisted therapy in pediatric dentistry.

Results: In preventive dentistry, good results can be achieved with fissure sealing in terms of good cleaning of deep pits and fissures and minimally invasive preparation of ampullate fissures, good microretentive surface pattern, and adhesive strength. In restorative dentistry, the Black class I and II minimally invasive cavity preparation cavities could be treated without anesthesia and with low loss of substance. In caries treatment, an additional benefit is the bactericidal effect of laser treatment. In pediatric oral surgery, the treatment of pericoronitis showed the best acceptance using the Er,Cr:YSGG laser, compared with the use of the diode laser or scalpel treatment. In laser treatment, often no anesthesia was needed, a minimally invasive, small flap was possible, hardly any bleeding occurred, and, depending upon the indication, no sutures were needed and therefore no further appointments for the children were necessary. The wound healing was very fast, with hardly any scarring, there was a positive bactericidal effect and biostimulation in the tissue, and, most importantly, no postoperative pain for the children. We found good acceptance by the children of the minimally invasive treatments.

Conclusions: In comparison with conventional treatment methods, laser therapy is a minimally invasive treatment method for many indications. In pediatric dentistry, especially anxious children benefit from laser treatment in terms of compliance with and acceptance of dental therapy. In addition to its good clinical results, it is a gentle approach that does not traumatize the child.

O-32. Er:YAG LASER, CARIOUS DECAY TREATMENT, AND DECIDUOUS TEETH

Introduction: Maintaining deciduous teeth as long as possible represents a goal in pediatric dentistry and prevents a list of health problems. Carious decay treatment with Er:YAG may help in prevention as well as curative processes.

Materials and methods: An Er:YAG laser was used to ablate 30 carious decays on primary teeth.

Clinical procedure: Diagnosis being conventionally addressed, treatment was conducted with the following parameters: Er:YAG laser (Lite Touch, Syneron) output power from 300 mJ (enamel) to 200 mJ (dentin), frequency 20 Hz, sapphire tip (diameter from 1.3 mm), air water spray-level 8/39 mL/min, pulse duration 50 μsec, theoretical fluence ranging from 15.08 J/cm² for dentin to 22,61 J/cm²/for enamel; cavity depth control, observation+probe, placement of glass ionomer cement filling (GC Fuji Triage capsule). Follow-up was conducted after 1 month and each month for a 1 year period, following previously considered protocol.

Results: Clinical cases illustrate the validity of this clinical approach. Children have been the biggest beneficiaries of laser therapy. On the other hand, the lack of studies evaluating laser ablation capacity in primary teeth hampers the effective application of this technology. The interaction between the Er:YAG laser and primary enamel and dentin depends upon the composition of the tissues – higher presence of water and lower presence of minerals, compared with the permanent enamel and dentin. Therefore, primary enamel and dentin need lower energy for ablating. This study shows that the parameters of Er:YAG laser 300 mJ/20 Hz for enamel and 200 mJ/20 Hz for dentin are enough efficient for the ablation of tissues of deciduous teeth.

Conclusions: Er:YAG laser cavity preparation is a part of the dental caries treatment with minimal intervention, and it is positively perceived by small children and their parents. Applying a correct approach and choice of optimal parameters are good conditions for successful caries treatment in primary dentition.

O-33. LASER PEDIATRIC DENTISTRY

Aim: Laser has been proven safe and effective for carious removal and cavity preparation and for many surgical procedures. Erbium lasers offer an alternative to the high-speed drill and to the blade, treating both hard and soft tissues, and eliminating fear and patient discomfort. The diode, Nd:YAG and CO₂ lasers offer an alternative to the blade in soft tissue therapies, introducing a new procedural approach, with high decontaminating and hemostatic effects, improving healing and postoperative recovery. This lecture offers a revision and a discussion of the interrnational bibliography of clinical procedures.

Materials and methods: Different laser wavelengths were used and will be presented, includinig near infrared diode laser (810 nm) and medium infrared Erbium lasers (Er,Cr:YSGG 2780 nm and Er:YAG 2940 nm).

Results: Laser technology offers wide and positive applications in pediatric dentistry, given its good acceptance by the child in comparison to traditional rotative instruments and blades, because of its minimally invasive approach, high decontamination level, pulp coagulation and vaporization, soft tissue incision or vaporization, and coagulation.

Discussion: Lasers offer three main advantages in dental and oral care: they can complete the usual dental procedures, with a very positive psycological influence on the patient; they can substitute conventional therapies with equal or at times better results; and, finally, they offer new opportunities for treatment, for example, using the laser for analgesic, biostimulating, and antiinflammatory effects.

Conclusions: For children's dental care, all the recognized advantages of laser technique play a decisive role in the successful day-to-day treatment of oral and dental pathologies. Laser technology can be integrated with conventional therapies, influencing and improving the positive acceptance of dental therapy.

O-34. PSYCHOLOGICAL AND PAIN EFFECTS OF THE MAX MODE OF THE FOTONA FIDELIS Er:YAG LASER ON PATIENTS, IN CLASS I FISSURE PREPARATIONS

Aim: The max mode of the Fotona Fidelis Er:YAG laser is considered to provide the maximum optical drilling speed available today. The aim of this clinical study is to examine and evaluate the patients' perception of pain or discomfort, and acceptance of the max mode of the laser in comparison with the high-speed drill.

Materials and methods: The laser used was the Fotona Fidelis Plus III Er:YAG laser with the RO2 noncontact hand piece and a maximum mode of 20 W. The high speed hand piece was the KaVo GENTLEsilence LUX turbine 8000B at maximum speed of 300,000 rpm with a cylinder shaped diamond bur (ISO 314 108 524 009). Both instruments were used with water spray and without anesthesia. Twenty Class I cavity preparations in permanent molars, one with each method in every patient, were performed in ten patients with clear medical history, low dental fear, previous drill experience, and no previous laser experience. Selection of the 20 molars was based on clinical and radiographic examination, and examination with the DÜRR DENTAL VistaProof camera (values 1.5–3.0), randomly distributed in the two groups. Patients' perception and acceptance of both instruments were evaluated using the Wong–Baker FACES^™ pain rating scale.

Results: The max mode presented 70% of the cases with absence of pain or discomfort, 20% with a small amount of pain or discomfort, and 10% with a little more pain or discomfort, whereas the drill presented 40% with a small amount of pain or discomfort, 50% with a little more pain or discomfort, and 10% with even more pain or discomfort. The high-speed drill results of pain or discomfort were higher than the max mode results in 80% of the cases, and the average pain or discomfort measurement was more than four times greater for the drill than for the laser.

Conclusions: The max mode was much better accepted by the patients, compared with the high-speed drill. All the patients noted that they would prefer laser treatment, even with the max mode, for future cavity preparations. These findings could suggest a possible wider use of this feature in cavity preparations.

O-37. NONSURGICAL NEW LASER PROCEDURE FOR PERIODONTAL POCKET ELIMINATION

Aim: The aim of this study was to measure the depth of the periodontal pockets before and after the laser treatment, to quantify the reduction of the pockets after laser application.

Material and methods: The study group consisted of 171 adults (87 males and 84 females), all Caucasian except for one Asian, with moderated or advanced chronic adult periodontitis, who volunteered for this study. For this study, 3884 remaining sites with probing depths of 4–6 mm were treated with an 810 nm diode laser (LaserSmile. Biolase technologies, Irvine CA).

Results: When the data were analyzed with the ANOVA for repeated measures using the Statistical Package for Social Sciences (SPSS version 15.0, SPSS Inc, IL), it was seen that after starting with 3884 remaining sites with probing depths of 4–6 mm, only 89 of them stayed as remaining sites, meaning that 97.71% of them were totally eliminated.

Conclusions: Based in an analysis of those results, it could be concluded that when using this “nonsurgical new laser procedure for periodontal pocket elimination,” following the protocol of use that has been detailed in this study, the vast majority of the remaining 4–6 mm periodontal pockets could be eliminated without the need for any kind of surgical procedure.

O-38. BIOPHYSICAL, CLINICAL, AND ERGONOMIC ASPECTS OF LASER-ASSISTED DENTAL IMPLANTS UNCOVERING IN VIVO AND EX VIVO EVALUATIONS

Aim: Implant surgery consists of two distinct techniques: transmucosal (also known as “one-stage”) technique, and the two-stages technique. The aim of contemporary research in implantology includes the development of minimally invasive surgical procedures, the reduction of rehabilitation time, and the possibility of obtaining a more rapid osseointegration. There is also a growing interest in the postoperative course, in terms of faster healing processes, less painful wounds, and better patient compliance. Lasers represent a possible aid in implant dentistry, especially in the two-stage technique. Main characteristics are a decreased trauma to bone and soft tissues, a reduction of pain, and a reduction of the risk of postoperative infections.

Materials and methods: The first part of this study analyzes in an animal model (swine mandible), the increases of temperature induced by four different laser wavelenghts (Diode, Nd:YAG, Er:YAG, KTP) during the implant uncovering. The second part of the present work is to compare the laser-assisted and the traditional technique during the surgical procedure of implant uncovering (183 implants positioned in 100 patients). Clinical parameters evaluated were: (1) duration of surgical procedures; (2) need for local anesthesia; (3) need for sutures; (4) discomfort and intra-and postoperative pain; and (5) length of time for tissue healing.

Results and conclusions: The results obtained at the end of the ex vivo tests was that the thermocouple recordered a lower increase in temperature for Er:YAG and KTP laser; Nd:YAG and diode laser produced similar increases characterized by higher values. The thermocamera pointed out the lower increase for Er:YAG and the higher increase for diode laser. KTP laser in uncovering implants more quickly, and diode laser needed more time. The in vivo data reveal that the use of laser optimizes the aesthetic and biological results and the management of economic resources.

O-40. PERIODONTAL TREATMENT WITH THE DIODE LASER AND ELECTROSURGERY: COMPARING CLINICAL AND HISTOLOGICAL FEATURES

Aim: The authors have compared, in this paper, both histologically and clinically, the results of linear incisions made on the oral mucosa by electrosurgery and an 810 nm diode laser, comparing the results with the consulted literature.

Materials and methods: The authors analyzed clinically and histologically, using both optical and electronic microscopy, the outcomes of clinical and histologic healing of linear cuts, made by an 810 nm diode laser and a L.A.S.E.R.T71C/b operating system, on the oral mucosa of 10 patients undergoing operations such as gingivectomy. Linear incisions were made by the same operator. Histologic sections were then made perpendicular to the examined mucosa and to the linear incision. Four histologic sections were made for each incision, and thus a total of 36 samples were then analyzed by optical microscopy, using 10× magnification. Sixteen histologic sections showed the effects of the cuts made by the laser whereas 20 showed the outcome of the electrosurgical incisions. Two electrosurgical treatments were also compared, by electron microscopy, with two similar treatments performed by a diode laser.

Results: The optical microscopy emphasized the width and depth of cut, whereas the electron microscope showed the extent of cellular damage. The four histological sections regarding each incision, made by the laser, showed, by optical microscopy, a width and a depth of cut similar in each section. A constant width of cut of 1.1 mm corresponded to a constant depth of cut of 1.1 mm. The histologic sections of the incisions made by the electrosurgery, showed instead a depth of cut, generally constant, associated with a cutting width that was sometimes variable. A generally constant depth of cut equal to 0.60 mm corresponded to a width of cut ranging from 0.55 to 0.10 mm. The histologic analysis, performed by electron microscope, pointed out the cytologic damage and ultrastructural changes such as pulverization of the squamous epithelium, caused by electrosurgery, with disappearance of the same. Electron microscope also showed an optimal result in diode laser cuts.

Conclusions: Histologic analysis performed by optical microscopy showed that the diode laser, compared with the electrosurgery, can provide greater depth of cut associated with a lower level of necrosis linear extension, and, therefore, of damage. A similar depth of electrosurgical cut causes a greater extent of linear damage. The laser thus provides clinically less invasive operative procedures associated with lower inflammatory responses and consequent optimal aesthetic results.

O-41. LASER THERAPY FOR PATIENTS WITH AGRESSIVE PERIODONTITIS

Aim: Aggressive periodontitis (AgP) is a quickly progressing periodontitis that is difficult to treat. The aim of this study was to evaluate the clinical and microbiological status of patients with AgP, following laser curettage.

Materials and methods: Twenty-eight patients with AgP (age 25–35 years): group 1, 14 patients were treated by scaling and root planning (SRP) and antimicrobial therapy; group 2, 14 patients were treated by SRP, antimicrobial therapy and laser curettage (980 nm diode laser, 1.8 W, continuous wave [CW]). Pocket probing depth (PPD) and relative attachment level (RAL) were measured with Florida Probe and gingival bleeding index. Periodontal bacteria were primarily identified by colony morphology under stereoscopic microscope and rapid biochemical tests.

Results: In 6 and 12 months after treatment, in group 2 the reduction of pocket depth was 1.2 mm (p<0.05), RAL increased on 0.8 mm (p<0.02), and gingival bleeding was absent. There were higher levels of Peptostreptococcus micros, Capnocytophaga spp., Porphyromonas gingivalis, Fusobacterium nucleatum, and Prevotella intermedia in subgingival plaque samples in the two groups before treatment. After treatment of group 2, P. gingivalis, F. nucleatum, and P. intermedia were not detected in any sample, and a decrease was found in the prevalence of P. micros and Capnocytophaga spp.

Conclusions: The follow-up 3, 6, and 12 months after treatment showed significant clinical and micribiological improvement in group 2.

O-42. CLINICAL EVALUATION OF THE EFFECTIVENESS OF LOW-LEVEL LASERS FOR DRUG-INDUCED GINGIVAL ENLARGEMENT

Aim: Drug-induced gingival enlargement remains a significant problem for the periodontologist. Gingival enlargement has been associated with a number of calcium channel blockers, including nifedipine, verapamil, diltiazem, amlodipine, and cyclosporine therapy. Many factors may contribute to the expression of drug-induced effect, such as genetic, drug variables (dose, serum/plasma concentration, tissue concentration), periodontal variables (gingival inflammation, plaque), age, sex, and concomitant medication. Clinical use of low-level lasers decreases gingival crevicular fluid and pro-inflammatory cytokines.

Materials and methods: Thirty subjects 20–65 years of age, presenting pseudopockets at least 5 mm deep in each quadrant, received initial periodontal treatment. The study had a split-mouth design. The control side only received scaling and root planing (SRP), and the test side (SRP+laser) was treated by both SRP and diode laser. Clinical conditions that were evaluated at day 0, day 90, and 1 year were plaque index (PlI), gingival index (GI), bleeding on probing (BOP), and pseudopockets probing depth (PD) values, measured as the distance from the bottom of the sulcus to the most apical portion of the gingival margin, not exceeding 4 mm in the whole dentition. The laser source was a diode possessing a wavelength of 810 nm, 200 μm fibers, set at a power of 0.8–1 W. Course of treatment using laser therapy included 10 visits.

Results: At the beginning of the investigation, the average GI value was 1.7 in both treatment and control sites. The decrease was statistically significant for both treatments between day 0 and day 90 (p>0.005). There were statistically significant differences between test and control sites (p>0.05). Average BOP value was initially 0.7 in both treatment and control sites. Both treatments modified the BOP (p>0.001), but differences between sites (test and control) were significantly different (p>0.05). The initial PD average was 4.5 mm (standard deviation [SD]=0.9) in the control sites and 4.6 (SD=0.9) in the test sites. After treatment, PD changed to 3.8 mm (SD=1.0) in the control sites and 2.4 mm (SD=0.4) for the test sites. Both treatments demonstrated a decreased pseudopocket probing depth (p>0.05). Differences between test and control sites were statistically significant (p>0.05). Use of the low-level laser in treatment of gingival enlargement 1 year later demonstrated a stable remission, normalization of gingival margin, and the absence of pseudopockets.

Conclusions: The investigations demonstrated that a significant decrease in clinical parameters ensues after initial periodontal treatment of gingival enlargement. Clinical use of laser radiation in the mode biostimulating 0.8–1 W allows avoidance of surgical operation on periodontal tissues that affects the aesthetic of the gingival margin, and is nontraumatic. The results clearly show that both treatment modalities were effective in decreasing the values of the clinical parameters used to evaluate periodontitis.

O-44. THE EFFICACY OF Er:YAG LASER ASSISTED PERIODONTAL PLASTIC SURGERY IN THE TREATMENT OF RECESSION DEFECTS

Aim: The aim of the present clinical case study was to evaluate the ability of Er:YAG laser to improve the clinical outcome of periodontal plastic surgery in the treatment of recession defects.

Materials and methods: Patients with Miller class I and II stable recessions were included in the study. Smokers, patients who had been on antibiotic treatment in previous 3 months, and patients with systemic diseases were excluded from the study. The recessions were treated either by laterally positioned flap (LPF), coronally advanced flap (CAF), or subepithelial connective tissue grafts (SCTG) alone or in combination with LPF or CAF. Er:YAG laser was added to each procedure to de-epithelize the recipient site, to condition the exposed root surface, and to precisely remove the excessive soft tissue. Primary and secondary outcome measures were recorded. Primary outcome measures were: aesthetic condition change related to patient's opinion (satisfactory, unsatisfactory, or not reported) and gingival recession change. Secondary outcome measures were: clinical attachment change, keratinized tissue change, percentage of sites with complete root coverage, mean root coverage, occurrence of adverse effects (yes/no), and/or postoperative complications (yes/no).

Results: Regarding the change of aesthetic conditions, the patients were most satisfied with modified CAF; however, all treatment modalities yielded aesthetically acceptable results. The highest gain in clinical attachment level was achieved with CAF; SCTG yielded the widest band of keratinized tissue and the highest percentage of root coverage. Adverse effects and postoperative complications were recorded after SCTG and LPF.

Conclusions: Er:YAG laser assisted LPF, CAF, and subepithelial connective tissue grafts alone or in combination with LPF or CAF may be used as root coverage procedures for the treatment of recession defects.

O-45. MORPHOLOGICAL EFFECTS AND TEMPERATURE INCREASE ON DIFFERENT IMPLANT SURFACES IRRADIATED WITH Er,Cr:YSGG, Er:YAG, CO₂, AND DIODE LASER: IN VITRO STUDY

Aim: Nowadays, a wide spectrum of treatment options for peri-implantitis exists, but none of them can guarantee a sufficiently high success rate. The aim of the present study was to assess the possible surface changes and temperature increases on different implant types after irradiation with several lasers.

Materials and methods: Six implant surfaces (TIO₂; SLA^®; platelet rich growth factor (PRGF) machined; grit-blasted and hidrofluoric acid-etched; excimer laser ablated; and ZrO₂ acid-etched surfaces) have been used. Four laser types with different wavelengths (Er,Cr:YSGG 2780 nm, Er:YAG 2940 nm, CO₂ 10,600 nm, diode 940 nm) have been included and the implant surfaces have been irradiated with various power settings (Er,Cr:YSGG 17.66 and 26.50 J/cm², Er:YAG 6.99 and 35.33 J/cm², CO₂ 200–1000 W/cm², diode 28.57 and 42.85 J/cm²). The samples were analyzed by scanning electron microscope, and temperature increase was measured with a thermocouple device.

Results: The Er,Cr:YSGG, Er:YAG, and CO₂ laser caused surface alterations in different degrees on the irradiated implants. The 940 nm diode laser only slightly affected the plasma-covered surface. During the thermocouple measurement with the 940 nm diode laser, temperature increase could be registered on all implants, with the ZrO₂ surface being more resistant to heat formation.

Conclusions: It was concluded that the laser effect on the implants is surface dependant and that the power settings and exposure time have an important influence on the results caused by irradiation. The amount of heat generation is also surface and power settings dependant.

Corresponding author: Simeon Dragov Kutnjak, E-mail: skutnjak@hotmail.com; address: Urb. Miraverde HLS-Center 1. Planta derecha, 38670 Costa Adeje, Canary Islands, Spain, Telephone and fax: +34922-715307

O-48. SEM EVALUATION OF THE EFFECT OF SODIUM HYPOCHLORITE SOLUTION ON Er:YAG - IRRADIATED DENTINAL CAVITIES FILLED WITH RESIN COMPOSITES

Background data: Previous studies have demonstrated that the surface of irradiated dentin showed the appearance of a thermally affected layer, which could reduce the quality of bonding. The removal of this thermally affected layer could improve the quality of dentinal bonding.

Aim: The principal objective of our study is to evaluate the effect of NaOCl solution on the quality of bonding of irradiated dentinal fillings.

Materials and methods: Crowns of 43 extracted human caries-free molars were used in our study. They were transversely sectioned to totally expose the dentin in which four standardized cavities were made. Two cavities were irradiated with Er:YAG laser (150 mJ, 10 Hz, very short pulse [VSP] mode [100 μsec], beam diameter = 0.9 mm, speed irradiation 1 mm/sec, 20% air and 20% water). Two cavities, one irradiated with Er:YAG laser and one non-irradiated, were treated for 30 sec with 5% NaOCl solution before standard treatment: acid/bonding/composite fillings. All cavities were immersed in a methylene blue solution at 0.5%. The percentage of the dye penetration (microleakage) in the composite-dentin interface was noted. Six supplementary permanent molars were used for scanning electron microscopic (SEM) observations.

Results: Results showed that dye infiltration was significantly reduced on irradiated cavities treated with NaOCl solution. SEM evaluation showed the removal of the thermally affected dentinal layer.

Conclusions: The application of NaOCl solution on irradiated cavities improves significantly the dentinal and marginal quality of composite bonding.

O-51. LIGHT ACTIVATED DISINFECTION USING A LIGHT-EMITTING DIODE LIGHT IN THE RED SPECTRUM: CLINICAL AND MICROBIOLOGICAL SHORT–TERM FINDINGS ON PERIODONTITIS

Background: Photoactivated disinfection (PAD) is a variation of photodynamic therapy (PDT), which has been used to treat a variety of dermatological problems over the last 20 years. The principle is to use a light source to activate a pharmaceutical applied topically or systemically. By activating the pharmaceutical specifically when in or close to target cells, efficiency is higher and side effects are considerably fewer. Recently, an increasing number of clinical studies have been published dealing with the adjunctive effects of PDT in periodontal treatment, using low-level power diode lasers and phenothiazine photosensitizers (mainly toluidine blue O [TBO] and methylene blue). There is controversial evidence arising from these trials, some showing no adjunctive effects, whereas other researchers reported better clinical results after an adjunctive single or multiple course of aPDT than with scaling and root planing (SRP) alone. The majority of clinical trials have used low-level diode lasers as the light emitting source to excite the photosensitizer, although, in principle, all type of lamps can be used if set on the specific excitement wavelength of the dye. Light-emitting diode (LED) lamps have some things in common with lasers: longer irradiation times are possible and lamps are cheaper and more user friendly.

Methods: In PAD, a chemical such as TB is used. TB has two important characteristics: (1) It attaches itself to bacterial membranes, and (2) when irradiated by red light (maximum absorption 626 nm) the molecule becomes excited (i.e., in a higher energy state). In the presence of oxygen, this energy is transferred to O₂, thus creating a free radical O^-.O^- is very reactive and destroys the bacterial membrane among others (a recent study indicates several intracellular effects on the bacteria), killing the bacteria instantly.

Results: The results of a clinical trial investigating the microbiological and clinical photodynamic adjunctive effect of a new LED lamp emitting in the red spectrum, compared with SRP in periodontitis patients in maintenance, will be presented.

O-54. ACTION OF THREE DIFFERENT LASER WAVELENGTHS ON A NEW LASER SINTERED IMPLANT SURFACE: SEM ANALYSIS

Aim: The aim of this study was to verify the effects of three different laser wavelengths (Er:YAG, Nd:YAG, and 980 diode) on a new implant surface, obtained by a laser sintering process from 20–40 μm particles of titanium alloy (Grade 5) (Tixos, Novaxa, Italy).

Materials and methods: Six specimens (1.5 cm diameter per 0.3 cm width) were subdivided into three groups, treated, respectively, with Er:YAG (Deka) (group A), Nd:YAG (Deka) (group B), and 980 diode laser (Lasering, Velure S9) (group C). The surface of each specimen was subdivided into four quadrants through a composite cross. Laser irradiation was performed in horizontal and vertical direction at 0.5 cm distance, leaving the first quadrant as control. The parameters were: 1 W, 1.5 W, 2 W, time, 30 sec, CW for 980 diode; 1 W (10 Hz; 100 mJ), 1.5 W (15 Hz; 100 mJ), 2 W (20 Hz; 100 mJ), time, 30 sec for Nd:YAG; 1 W (10 Hz; 100 mJ), 1.5 W (15 Hz; 100 mJ), 2 W (20 Hz; 100 mJ), time, 30 sec for Er:YAG. After irradiations, all specimens were metallized and analyzed to SEM (500×–5000×) to verify structural surface modifications. Finally, an imaging analysis program (ImageJ) was used to evaluate the variation of fractal dimensions of the specimen surfaces.

Results: SEM images show melting zone in specimens treated with Nd:YAG and 980 diode. Very little difference in fractal dimension was noticed in surfaces treated with Nd:YAG and 980 diode; no significant variations were found in the one treated with Er:YAG.

Conclusions: In this preliminary study Nd:YAG and 980 diode showed more invasiveness than Er:YAG. Nevertheless, more studies are necessary to assess whether these surface alterations may influence implant osteointegration.

O-55. COMBINED EFFECT OF Nd:YAG LASER AND TiO₂ ON BACTERICIDAL ACTION

Background and objective: Recently, numerous experiments and clinical applications have reported the effect of Nd:YAG laser irradiation with TiO₂ suspension. The aim of this study was to evaluate the bactericidal effects of Nd:YAG laser by using TiO₂ as a reaction mediator.

Methods: The high peak pulse type Nd:YAG laser (STREAK ALTEK Co., Tokyo) was used for this experiment. Two strains of bacteria such as Streptococcus mutans ATCC 25175, Streptococcus sobrinus ATCC 33478 were provided and added into 10% TiO₂ suspension. Bacterial cell suspensions of each strain were divided into four groups. Non-irradiated samples (cell suspension alone and cell suspension with TiO₂) were used as control. Cell suspensions with and without TiO₂ were irradiated with the Nd:YAG laser at 900 mJ 10 pps, total energy 1500 J under the controlled temperature of reaction mixture. In addition, the surface of the irradiated bacterial cells was observed under a scanning electron microscope (SEM).

Results: After the treatments, the viable cell count was estimated in each group. The mean colony-forming units (CFUs) of S mutans for control groups and irradiated groups without and with _TiO2 were 1 × 106.2 × 106.7 × 106.4 × 10³ CFU, respectively. The mean CFUs of S. sobrinus irradiated with TiO₂ were 2 × 10³ CFU. The bactericidal effects of the Nd:YAG laser with TiO₂ showed the significant reduction of viable cells of S. mutans and S. sobrinus after laser irradiation with total energy 1500 J. The SEM investigation revealed damage patterns on both strains.

Conclusions: Our study demonstrates the bactericidal effects of Nd:YAG laser by using TiO₂ reaction mediator. It might be possible that the bactericidal action revealed an induced dynamic stress by Nd:YAG laser irradiation and TiO₂ as a reaction mediator.

O-57. USE OF Er:YAG LASER IN RESTORATION OF THE BOVINE INCISORS AFTER TRAUMATIC FRACTURE: IN VITRO STUDY

Background: Nowadays, a traumatic-broken fragment of a fractured tooth can be bonded to the tooth in order to obtain a good restoration, in terms of aesthetics, mechanical strength, and microleakage reduction.

Aim: The purpose of this study was evaluation of the compression resistance (measured by a Newton-calibrated dynamometer) of the tooth fracture; the evaluation of any possible microleakage at the interface between the composite and the tooth fragment when glued back in place, by using optical microscopy, comparing three different preparation methods: Er:YAG laser, 37% orthophosphoric acid, and Er:YAG + 37% orthophosphoric acid.

Methods: Seventy-two bovine incisors freshly extracted were broken by a hammer, in a standardized way. They were randomly subdivided into three groups of 24 teeth each. The restoration was performed by: (A) Er:YAG laser (150 mJ, 10 Hz); (B) 37% orthophosphoric acid; and (C) Er:YAG + orthophosphoric acid. Each group was randomly subdivided into subgroups A-B-C (for Group I = IA – IB – IC and for Group II = IIA – IIB - IIC) of 12 teeth each. Group I was used to measure the force required (measured in Newtons) to detach the fragment that had been glued back in place using a flow test (compression test). Group II was treated with transparent nail varnish and then immersed in methylene blue solution at 0.5% concentration. Examination of each fragment was done using an optical microscope.

Results: The data of the fracture forces under compression of Group I do not highlight significant differences. Regarding the infiltration test: (1) Samples etched with Er:YAG laser showed an infiltration level of degree 0 in 23/24 observations. (2) For the teeth etched with orthophosphoric acid 37%, 14/24 samples demonstrated deep infiltration of degree 3, whereas 10/24 samples showed an infiltration degree of 0. (3) In teeth etched with the Er:YAG laser + orthophosphoric acid 37%, it was observed that 20/24 of the samples observed presented degree 0 infiltration.

Conclusions: The compression test showed that there was no significant difference among the three etching systems. The infiltration test used to evaluate the marginal seal of the area of adhesion has demonstrated that etching with an Er:YAG laser on its own or with orthophosphoric acid was superior to etching with orthophosphoric acid alone.

O-58. INVESTIGATION OF ACCIDENTAL Er:YAG LASER IRRADIATION OF AMALGAM FILLINGS AND THEIR CONSEQUENCES FOR RESPIRATORY INTAKE AND MATERIAL WEAR

Aim: It is well known that the removal of amalgam fillings is a contraindication for the use of lasers, and even the accidental exposure to a laser beam should be avoided. However, it remains unknown how large the respiratory intake of ablated particles is for the patient as well as the dentist, and to what extent damages will occur to the laser applicator.

Materials and methods: We prepared 15 extracted human molars and premolars with amalgam fillings, which were then placed in a phantom head's upper and lower jaw. At nose level of the phantom head and collar of the dentist a suction system was installed and the air filtered by means of aerosol monitors. Amalgam fillings were lased by an Er:YAG laser for 30 sec at the junction between amalgam and enamel with settings of 100 μs, 300 mJ, and 30 Hz with a tip-based applicator, and 350 μs, 1000 mJ, and 20 Hz with a free-beam focusing applicator. The filters were evaluated gravimetrically and by light microscopy after irradiation was completed.

Results: The gravimetric analysis did not show significantly higher values for the laser irradiated amalgam than for a bur control. Optical investigation showed contamination only on isolated filters. Deterioration of the laser tips and outcoupling windows was extremely high, lasting only for 1–2 fillings.

Conclusions: As expected, irradiation of amalgam fillings is to be avoided, but exposure to hazardous material seems to be limited for both patient and dentist.

O-65. LASER AND NANODISINFECTION IN ENDODONTICS

Background: Laser technologies for diagnostics and therapy in stomatology continue to find wider application. They have had especially convincing results in the area of endodontics, which constitute a critical strategy of tooth maintainance. Most has been said about the disinfection of root canal systems. The rapid development of nanotechnologies is instrumental in their introduction in medicine and dentistry. In this connection, the architectonics of the hard tissues of teeth selects them as an extraordinarily interesting object for laser and nanotechnologies. The original structure of dentinal tubules with the substantial difference of indexes of refraction of peritubular (walls of tubules) and intertubular dentine, and their spatial orientation, predetermine the special optical properties of dentine, and the stereometric sizes of tubules are accessible for free penetration of nanofunctional agents.

Aim: The purpose of this study was to examine the comparative experimental efficiency of the powerful irradiations of Nd:YAG, KTP lasers, metal nanoparticles (Ag, Au), complexes (Au:TiO2), and their combination (additional activation of nanoparticles with laser radiation) in the disinfection of root canals of teeth.

Results: There was deep penetration of nanoparticles in dentinal tubules for 20 μm in the mode of free penetration of Ag nanoparticles and >60 μm in the mode of shock laser wave. The microbiological analysis of the bactericidal properties of nanoparticles was conducted on the culture of Escherichia coli and Enterococcus faecalis in the root canal system. The Ag nanoparticles showed more antimicrobial activity. Complexes of Au:TiO2 showed the greatest activity during activation with the second harmonic of Q-switched YAG:Nd laser (wavelength 532 nm), and that sufficiently for blocking entrance and exit of bacteria in the root canal system.

Conclusions: The synergistic effect of bactericidal influence of metal nanoparticles was improved with the use of laser radiation. Modern laser equipment and methods of delivery of laser beam were examined in a root canal.

O-67. U.SE OF Er:YAG LASER IN ADHESIVE ENDODONTIC FIBER POST CEMENTATION: A NEW CLINICAL APPROACH

Aim: The aim of this study is to evaluate the effect of the Er:YAG laser on the fiber post adhesive cementation process after irradiation of the post surface and the canal walls.

Background: Nowadays, the possibility of performing a conservative restoration of a tooth by using an endodontic fiber post retention, is growing among clinicians. The two main problems reported in the literature are the interfaces between the cement and the post surface and the cement and the canal walls of the post space.

Materials and methods: We evaluated the performance of the bonding strength of endodontic quartz fiber post after laser irradiation on the post surface itself and the canal walls of the endodontic space, using the Er:YAG laser. We prepared three groups: (1) C group following instructions of the manufacturer. (2) PL group: the post surface treated with the Er:YAG laser. (3) L group: treated both the post surface and the canal walls of the post space. The post was treated using an output power of 80 mJ, 5 Hz, mirror handpiece, pulse duration 50 μsec (super short pulse [SSP]), fluence = 40.81 J/cm² in order to maintain the integrity of the fibers. The canal walls were treated using the settings of 120 mJ, 10 Hz, fiber 300, fluence = 171.42 J/cm² with the use of ethylenediaminetetraacetic acid (EDTA) liquid solution 17%, five passages, in order to remove the smear layer and improve the penetration of the bonding agent. The push-out test on an in vitro study demonstrated statistically significantly better values for the parameters concerning force and compression, especially in the PL group.

Results: The results obtained were as follows: group C: force, 86.91 N; compression, 9.9 MPa. Group PL: force, 122.14 N; compression, 18.87 MPa. Group L: force, 63.14 N; compression, 5.05 MPa. The values obtained were significantly higher in terms of force of adhesion in group PL compared with group C. Many samples of group L broke during the test, probably because of the dehydration of the tissues after the irradiation with laser, and no statistically significant difference was detectable with the other groups. On the other hand, the differences between the scores obtained for group PL and group C were significantly different (p value: 0.0062).

Conclusions: This in vitro study seems to demonstrate the efficiency of the Er:YAG laser in the pre-treatment of the endodontic quartz-fiber posts before the adhesive endodontic post cementation procedure.

O-68. ENDODONTIC TREATMENT WITH AND WITHOUT ADDITIONAL Nd:YAG LASER TREATMENT IN A GENERAL DENTAL CLINIC

Aim: Adjunctive treatment with the Nd:YAG Laser is a well-researched method in endodontic treatment. It is notable that in revision of unsuccessful treatments in the past and treatment of extended apical periodontitis and/or periapical abscess, the laser can be very helpful. The review of root canal treatments in the years 2000–2008 in teeth with a radiographically visible apical periodontitis of ≥2 mm in our practice has shown more success when Nd:YAG laser was used additionally in endodontic treatment. The results of review and clinical treatment protocol will be represented here, and some cases that were on the border of surgical treatment will be shown.

Materials and methods: From 2000 to 2008 in our practice, 487 root canals with radiographically visible apical periodontitis of ≥2 mm had endodontic treatment; 254 root canals were treated chemo-mechanically (group 1) and 111 were additionally treated with laser treatment (group 2). Fifty-four root canals received a revision of root canal treatment without laser (group 3); 68 with laser (group 4).

Results: In a follow-up after an average of 24.8 months, 59% of the root canals in group 1 were healed completely; in 75% we saw an improvement and the lesions were smaller. In group 2 with additional laser treatment the follow-up was 19.1 months; 88% of the treated root canals were healed completely and in 91% the lesions were smaller. The conventional revision of root canal treatment showed a complete healing in 30%; in 78% an improvement was seen in a follow-up after 18.5 months. With the additional laser treatment we saw a complete healing in 73% of the cases, and 96% showed a reduction of the granuloma in a follow-up after 15 months.

Conclusions: Using Nd:YAG laser additionally in endodontic treatment has shown more success, especially in revision of failed root canal treatments.

P-3. A COMPARISON BETWEEN ANTIMICROBIAL PHOTODYNAMIC THERAPY AND ANTIBIOTIC THERAPY IN PATIENTS WITH AGGRESSIVE PERIODONTITIS

Aim: Recent studies have suggested a potential benefit of antimicrobial photodynamic therapy (aPDT) in the treatment of periodontitis. The aim of this study was to compare the effect of scaling and root planning in combination with systemic antibiotics (SRP and ATB) with the effect of SRP in combination with aPDT (SRP and aPDT) in patients with aggressive periodontitis.

Materials and methods: Twenty patients with untreated aggressive periodontitis were randomly divided into two groups: the test group received a combination of SRP and aPDT (two episodes of PDT using a laser source with a wavelenghth of 660 nm associated with a photosenzitizer) and the control group received a combination of SRP and ATB (500 mg amoxicillin and 400 mg metronidazole three times a day for 8 days). Clinical parameters of probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP) were measured at baseline, 3 months, and 6 months after treatment.

Results: The mean probing pocket depths at baseline were 3.68 mm (±1.88) in the test group and 3.51 mm (±1.84) in the control group. These values decreased to 2.77 mm (±1.06) (p<0.05) and 2.54 mm (±0.83) (p<0.05) 3 months after treatment and to 2.85 mm (±1.16) (p<0.05) and 2.47 mm (±0.76) (p<0.05) 6 months after treatment. Clinical attachement levels decreased from 3.88 mm (±2.15) to 3.06 mm (±1.43) (p<0.05) after 3 months and 3.13 mm (±1.47) (p<0.05) after 6 months in the test group and from 3.70 mm (±1.91) to 2.80 mm (±1.09) (p<0.05) after 3 months and 2.80 mm (±1.08) (p<0.05) after 6 months in the control group. There was also a decrease in sites with bleeding on probing after 3 and 6 months in the test (45%–10%–6%) and in the control (42%–8%–8%) group.

Conclusions: Both treatments (SRP+ATB and SRP+aPDT) led to significant improvements in clinical parameters 3 and 6 months after treatment.

P-4. PITS AND FISSURE SEALING OF FIRST PERMANENT MOLAR USING Er:YAG LASER: CASE REPORTS

Aim: The aim of this study was to compare Er:YAG laser enamel preparation before fissure sealing to traditional acid etching, which is the evidence-based method for enamel preparation before sealing of the first permanent molars after 1, 2, and 3 years, evaluating the sealants' retention rate and the status of the teeth.

Materials and methods: At the baseline of the study, 92 children aged 6–9 with caries-free permanent molars, randomly received 168 sealants after using Er:YAG laser (Fidelis Plus II, Emmeciquattro Fotona, Italy) (group A) and 168 sealants using the acid etching method (group B). The status of occlusal surfaces of molars was scored as caries-free or decayed/restored by visual clinical assessment evaluation after 1, 2, and 3 years.

Results: The sealants' retention rate was 97.5%, 91.4%, and 62.3% in group A and 96.9%, 92.1%, and 61.8% in the acid etching group B after 1, 2, and 3 years, respectively. The results showed 98.5%, 98.2%, and 97.7% caries-free occlusal surfaces of molars prepared with laser method and 99.7%, 99.4%, and 96.9% caries-free occlusal surfaces of molars prepared with acid etching method after 1, 2, and 3 years, respectively.

Conclusions: The differences between the two methods for enamel preparation before fissure sealing of first permanent molars in terms of sealant retention rate and caries development appeared to be not statistically significant (p>0.05).

P-6. ASSESSMENT OF POSTOPERATIVE PAIN IN PATIENTS TREATED WITH COLD BLADE, QUANTIC MOLECULAR RESONANCE SCALPEL, Nd:YAG LASER AND Nd: YAG LASER ASSOCIATED WITH AMINOGAM^®

Aim: The purpose of this study is to evaluate and compare the postoperative pain resulting from different surgical techniques.

Methods: Four hundred and seventy-eight patients received 487 oral surgical treatments from 2004 to 2011. Interventions included excisional and incisional biopsies, frenulectomies, gingivoplasties, and gingivectomies. One hundred and sixty-five sites were treated through the use of cold blade, 213 through quantic molecular resonance (QMR) scalpel (BLADION^®), 73 through Nd:YAG laser (Fidelis Fotona^®) and 36 with Nd:YAG laser associated with application of an aminoacid and hyaluronic acid gel (Aminogam^®) three times a day for 1 week. Three days after surgery, patients filled out a questionnaire to assess the postoperative pain, through the use of visual analogue scale (VAS), verbal analogue test (AV) and present pain index (PPI). Nonsteroidal anti-inflammatory drugs (NSAIDs) consumption was also recorded.

Results: The average of VAS value in patients treated with cold blade was 15.87, and the average of AV was 2.06. Sixty-seven patients (41.1%) complained of pain and 59 (36.2%) used NSAIDs during the postoperative period. In patients treated with QMR scalpel, the mean of VAS was 15.14, and the mean value of AV was 2.02. Sixty-six patients (31.1%) reported pain relief and 68 (32.8%) used NSAIDs. The average of VAS was 12.16, and the average of AV was 1.81 in patients treated by Nd:YAG laser. Twenty-nine patients (39.7%) complained of pain and 24 (32.9%) used NSAIDs. Finally, in patients treated with Nd:YAG laser and Aminogam^®, the mean of VAS was 10.7 and the mean of AV was 1.38. Ten patients (27.8%) reported pain and eight (22.2%) used NSAIDs.

Conclusions: Patients treated with Nd:YAG lasers have a better postoperative course and applications with a drug promoting re-epithelialization, such as Aminogam, can decrease the postoperative symptoms.

P-8. CARIES REMOVAL EFFECTIVENESS OF DIFFERENT CARIES-EXCAVATION TECHNIQUES: A DIAGNOdent INVESTIGATION

Aim: The aim of this in vitro study was to compare the caries removal effectiveness of Er:YAG and Er,Cr:YSGG lasers with conventional caries excavation techniques.

Materials and methods: Seventy-two extracted human molars having D3 grade occlusal caries lesions were flattened to expose dentin surfaces. The specimens were divided into six groups according to the cariesexcavation techniques used; G1: intact dentin (positive control); G2: carious dentin (negative control); G3: hand excavation; G4: bur excavation; G5: Er:YAG laser excavation (200 mJ, 20 Hz) (LiteTouch™, Syneron Dental Lasers, Yokneam/Israel); G6: Er,Cr:YSGG laser excavation (200 mJ, 20 Hz) (Waterlase MD Turbo, Biolase,CA). Following the completion of caries removal procedures, all the specimens were checked for residual caries using DIAGNOdent (Kavo, Biberach/Germany). The DIAGNOdent readings were repeated three times for each specimen. The data were subjected to statistical analysis using the Kruskal–Wallis test (p=0.05).

Results: Er:YAG laser, Er,Cr:YSGG laser, and conventional bur excavation techniques were found to be effective in caries removal (p<0.05), but there were no significant differences among those three techniques (p>0.05). Caries removal effectivenes of hand excavation was lower than the other techniques (p<0.05).

Conclusions: Er:YAG and Er,Cr:YSGG lasers could be good alternatives to conventional bur excavation for effective caries removal.

P-10. COMPARED ANALYSIS OF SHADE, TEMPERATURE, AND HYDROGEN PEROXIDE CONCENTRATION DURING DENTAL BLEACHING: IN VITRO STUDY WITH KTP AND DIODE LASER

Aim: In the last several years, many bleaching techniques have been proposed and several of them using laser would improve the bleaching result. Opinions about the exact role of coherent light on the biochemical reaction, which leads to the whitening process, are very discordant.

The aim of the study is to examine three different factors at the same time, to obtain information on bleaching process comparing two different laser sources.

Materials and methods: This study was performed by observing the gel temperature during the bleaching process; hydrogen peroxide concentration and teeth shade variation before and after bleaching procedure were recorded also. Altogether, a sample of 160 bovine teeth were bleached using a 30% gel of hydrogen peroxide. Some of them were bleached using gel only, whereas others were bleached using gel plus light laser in two different wavelength, 532 and 810 nm and two different power levels, 2 and 4 W.

Results: Data obtained show that KTP is the only laser to produce a significant shade variation coupled with a minimal temperature increase. Diode laser caused a higher temperature elevation and the most important, diminishing of hydrogen peroxide concentration, but statistically significant result in term of shade variation was obtained only using the 4 W regime. Shade variation results of diode laser were lower than those obtained using KTP laser with the 2 W regime.

Conclusions: In this study, KTP laser appeared to be better than diode laser when used in dental bleaching, obtaining better results with less dangerous thermal increase. This result might call into question most of the literature that affirms bleaching methods act only with the increase of the gel bleaching temperature by improving the speed of the bleaching reaction. Further study is needed to investigate the correlation between variations of the parameters investigated and efficacy of the bleaching process.

P-11. DENTAL HYGIENISTS AND LASER-SUPPORTED DENTISTRY

Aim: The regulations and guiding recommendations from authorities are not clear concerning the possibility and legal qualification for dental hygienists in Sweden to perform oral treatment supported by laser. Nevertheless, in the fields of prophylactics, oral diagnostics, periodontics, cariology, and aesthetics we find examples in which laser support is beneficial for both operator and patient. This presentation aims to discuss these subjects.

Materials and methods: The presentation contains examples of treatment protocols, comparison with conventional dental hygienist treatments, and a necessary argument.

Results: Hygienists who have obtained appropriate knowledge in safe and evidence-based treatment methods in laser-supported dentistry may be an important factor in oral healthcare in the future, both for economical reasons and with the patients' general condition in mind.

P-12. DIODE 810 NM ASSISTANCE IN CONVENTIONAL PERIODONTAL TREATMENT

Aim: Treatment of periodontal pockets may be conducted with the assistance of infrared radiation and specifically diode lasers. This clinical report aims to demonstrate that more than conventional general management of periodontal pockets, diode laser may help in decontamination and, subsequently, during the healing process.

Materials and methods: General Management, first step: radiographs, measurement of periodontal pockets, clinical attachment loss, probing pocket depth, bleeding on probing, and bacteriological tests serve for diagnosis. Second step: preoperative treatment includes water pulse, tooth brushing for 15 days with bicarbonate +H₂O₂ mixture twice a day, betadine mouth rinse for 7 days twice a day. Third step: ultrasonic treatment (topical anesthesia), subgingival debridment+betadine+Calbenium^®, scaling, air-flow, irrigation with H₂O₂. Lasering – the following parameters were used: fiber placement in the depth of the pocket always in motion from the bottom to the crown, 10 times. Parameters: output power 2 W, frequency 50 Hz, fiber 300μm, power density 2830 W/cm². Postoperative management: biomodulation output power 1 W reduced to 0.5 W modifying the working distance. Tooth brushing with bicarbonate +H₂O₂ once a day for 6 months and subsequently, twice a week.

Results: Results were evaluated via controls at 2, 6, and 12 months, the patient being submitted to bleeding control, scaling (if necessary), and x ray control once a year.

Conclusions: Periodontal treatment involves the patient as well as the dental practitioner. Diode laser represents one step in this treatment, but helps to decontaminate in three dimensions and, when used with low energies, in the healing process.

P-13. DIODE 980 NM IN CURRENT ORAL SURGERY

Aim: The aim of this study was to report some clinical cases with different oral pathologies excised with a 980 nm diode laser.

Materials and methods: A 980 nm diode laser (Doc Medica, Italy) was used with the following parameters (fiber diameter 200 μm, output power 3 W, continuous mode, power density 9554 W/cm²) to ablate different oral pathologies (papilloma, nevus, fibroma) and treat blood pearls (angioma). Contact mode was used for all pathologies with the exception of angioma (working distance from 3 to 1 cm). Samples were prepared for anatomopathological examination to confirm the clinical diagnosis. Healing process was observed 1 week to 1 month after surgery.

Results: Excision was reached after a maximum of 1 min, and dessication of the heamangioma took 10 sec to 1 min. During excision, bleeding was never observed even in patients taking antiaggregants. During management of the postoperative period, no antibiotics or anti-inflammatory drugs were ordered. Healing of the wounds was considered totally obtained after a 1 month period.

Conclusions: Diode 980 nm was demonstrated to be a safe methodology to manage different oral pathologies.

P-18. EFFECTIVENESS OF KTP AND DIODE LASERS IN THE SURGICAL TREATMENT OF ORAL PATHOLOGICAL FRENULA

Aim: The aim of this work was to evaluate the clinical efficacy of two different wavelength lasers in the surgery of labial and lingual pathological frenula.

Materials and methods: KTP laser (SmartLite®, DEKA, Calenzano FI, Italy, 532 nm) and diode laser (Wiser®, DoctorSmile, Brendola VI, Italy, 980 nm) were used to perform oral labial and lingual frenectomies. A standardized surgical protocol was applied.

Results: Follow-up at 7 and 30 days always showed a complete healing of the surgical wounds with excellent clinical results. In most cases, patients had no pain or postoperative complications, and did not take any analgesic drugs.

Conclusions: Tested lasers made surgical steps easier, an allowed for excellent control of bleeding. In some cases, less anesthesia was necessary. However, the operator must understand the correct indications and techniques of the surgery.

P-20. EXPERIMENTAL STUDY ON THE ANALGESIC AND HEALING EFFECTS OF DIODE LASER WITH REGARD TO RECURRING APHTHOUS STOMATITIS

Aim: One of the most frequent pathologies of the oral cavity is recurring aphthous stomatitis (RAS). This multifactor immunologic inflammatory lesion causes patient discomfort, and treatment is controversial because of the lesion's unknown etiology. The aim of the present study was to assess the effect of diode laser on the control of pain and the repair of RAS.

Materials and methods: Fifty patients with RAS (both sexes, mean age 34 years, no smokers) were divided into an experimental group of 25 patients treated with diode laser and a control group treated with a topical corticoid agent. The first group was treated with diode laser with wavelength of 670 nm, 50 mW, 3 J/cm² per point in daily sessions (once per day) on consecutive days. The second group received conventional treatment with triamcinolone acetonide four times per day. Both treatments were applied until the disappearance of the lesions. Pain intensity before and after treatment and clinical measurement of lesion size were determined daily for all patients.

Results: The results revealed that 81% of the patients reported a reduction in pain in the same session after laser treatment, and total regression of the lesion occurred after 4 days. Total regression in the corticoid group was from 4 to 7 days.

Conclusions: The use of diode laser demonstrated analgesic and healing effects on recurring aphthous stomatitis.

P-24. INCIDENCE OF POSTOPERATIVE PAIN AFTER SINGLE-VISIT ENDODONTIC DIODE LASER-ASSISTED TREATMENT IN TEETH WITH NON-VITAL PULP

Aim: In this research, we tried to assess the incidence of postoperative pain after single-visit endodontic treatment of teeth with non-vital pulp comparing conventional endodontics with laser-assisted treatment.

Methods: In total, 72 patients with non-vital teeth requiring endodontic treatment were identified and were included in this study. The patients were treated by the same experienced clinician, and were randomly assigned into two groups. Whereas the teeth of patients in group 1 were treated and conventionally obturated, in group 2 the teeth were sealed after diode laser-assisted endodontic decontamination according to the Moritz protocol. One day, 3 days and 1 week after the root canal instrumentation of each tooth, the patients were asked whether they experienced any postoperative pain and to rate the level of discomfort as none, mild, moderate, or severe pain. Data were statistically analyzed using the Kruskall–Wallis test (significance) and the Dunn's test comparison.

Results: No significant difference in postoperative pain was found between laser-assisted and conventional endodontics. There was no significant difference in postoperative pain between the two groups, even though pain occurred slightly less in laser-treated patients and in patients with preoperative pain.

Conclusions: The prevalence of postoperative pain did not differ between laser-assisted and conventionally treated non-vital teeth. Moreover, this study confirms that endodontic treatment confined to a single visit performed on teeth with non-vital pulp can be performed successfully with no risk of postoperative pain. The majority of patients in both groups reported no or only mild pain after 1 week.

P-25. THERAPEUTIC COMPARISON OF TRADITIONAL SURGERY AND Nd:YAG LASER IN PATIENTS WITH STURGE–WEBER SYNDROME

Aim: The aim of the present study is to compare two different surgical procedures in the treatment of angiomas in Sturge–Weber syndrome.

Materials and methods: We made use of different cases treated with two procedures: some were treated using a cold blade and others, more recent, using Nd:Yag laser.

Results: Postoperative results are very clear: patients treated using a cold blade, without laser, have to be treated more frequently (every 1–2 years) than patients treated with Nd:Yag laser, who are treated with a 4 year frequency.

Conclusions: Angioma re-growth is a very common occurrence in patients with Sturge–Weber syndrome. In the light of this, treatment with Nd:Yag laser seems to be the right choice, because it reduces the frequency of angioma re-growth and significantly improves the patient's postoperative course.

P-28. LASER THERAPY IN RETROGRADE PERI-IMPLANTITIS. CASE REPORTS

Aim: The term “retrograde peri-implantitis” is commonly used to describe lesions in the periapical region of a dental implant. Information about the etiologic factors, incidence, and treatment of retrograde peri-implantitis is scarce and mostly collected from some sporadic case reports. The aim of this study is to evaluate the treatment of apical peri-implantitis with the use of diode laser therapy.

Materials and methods: Two patients were extensively evaluated with regard to clinical and radiographical signs. In both cases a Tc Cone beam was performed pre- and post-laser therapy. Initially, the use of systemic antibiotics and the use of 0.2% clorhexidine digluconate solution (Corsodyl) failed to subdue the infection. After 2 weeks patients were treated with the laser procedure. The protocol included the use of a diode laser device emitting a pulsed infrared radiation at a wavelenght of 980 nm. Patients were followed at 1 week, 1 month, 3 months, 6 months, and 1 year postoperatively.

Results: At 1 month follow-up, neither patients had pain or discomfort. No complications such as abscesses or infections were observed. At 3 month follow-up, further progress of bone healing was observed. At 6 month and at 1 year follow-up, Tc Cone beam showed an increase of bone density and a new bone formation at the apical region of the implant. Patients remained asymptomatic.

Conclusions: The incidence of retrograde peri-implantitis may diminish by increasing the duration from endodontically treated tooth to implant placement, although treatment of peri-implantitis lesions with diode laser resulted in a significantly higher pain and discomfort reduction and efficacious treatment.

P-29. LOW LEVEL LASER THERAPY IN PAIN ASSOCIATED WITH TEMPOROMANDIBIULAR JOINT (TMJ) DISORDERS

Aim: Masticatory muscle myofacial pain is a common temporomandibular disorder (TMD) associated with pain and limited function of the masticatory system. The effects of low-level laser therapy (LLLT) for controlling discomfort of patients are frequently investigated, because of its recognized anti-inflammatory and analgesic properties. The aim of this systematic review is to analyze studies examining the effectiveness of LLLT in the treatment of TMD.

Methods: A literature research of published articles in the last 10 years resulted in the retrieval of 19 potential articles.

Results: These 19 studies, supported by statistical data, showed that LLLT: (1) causes an improvement in muscle contraction strength; (2) causes an improvement in maximal mouth-opening; (3) is effective in reducing TMD symptoms, and has influence over masticatory efficiency; (4) may be more effective than other electrotherapy modalities; and (5) in different laser wavelengths (lambda 660, 780, 790, or 830 nm), can be used and the association of red and infrared laser light is effective in pain reduction.

Conclusions: LLLT is effective in reducing TMD-associated pain.Therefore, is not possible to establish a treatment protocol. LLLT could be a possible treatment of TMD in association with a combination of active exercises, manual therapy, postural correction, and use of occlusal splints.

P-31. LASER-ASSISTED ORTHODONTICS

Aim: A diode laser with an 808–980 nm wavelength and photo thermal laser–tissue interaction were used in this study. Laser was applied surgically on soft tissues during orthodontic treatments; it was also used with a defocused hand piece for biostimulation and analgesic therapy. Laser-assisted orthodontics have several advantages for the patient and for the clinician as well: no infiltration anesthesia (except for lingual frenectomy) or sutures are required, there is no pain or post-surgery edema, and intra-surgery time is short. Furthermore, predictability is clear for the clinician. There are, nevertheless, some contraindications.

Materials and methods: A 400 μm fiber was used surgically for the following operations: tectolabial upper central frenectomy, lingual frenectomy, remodeling and reconditioning of the gum line and of hypertrophic gingival margins, and exposure of impacted teeth. Laser was employed with a continuous wavelength and a defocused hand piece for biostimulation of pre-implant sites and analgesic therapy of temporomandibular joint disorders (TMJD) and correlated muscles.

Results: The diode laser proved to be a useful and reliable tool for orthodontic surgery and during therapy, as well as being useful for analgesic therapy of TMJ and regeneration of pre-implant sites.

Conclusions: Laser-assisted orthodontics make treatment faster and more comfortable while simplifying various fundamental phases of therapy both for the patient and the clinician; in several cases, laser-assisted orthodontics could be considered an improvement over traditional surgery. There are contraindications to laser use; nevertheless laser therapy is almost painless for the patient, even though there are some contraindications that have to be respected, such as: (1) irradiation is forbidden in cancer or other progressive pathology; (2) no irradiation is allowed for thyroid or the pregnant uterus; (3) blood vessel diameter increasing can provoke hemorrhage in diabetes cases; (4) photosensitization is possible when antibiotics, steroids, or cortisone therapy is in progress; (5) patients with a pacemaker do not have to be treated. After 10–15 days there is a satisfactory restitutio ad integrum.

P-32. Nd:YAG DOUBLED FREQUENCY REMOVAL OF A BUCCAL ANGIOLIPOMA

Aim: Angiolipoma (AL) is a relatively rare tumor of the head and neck region, although it occurs more commonly in the extremities and the trunk regions. When seen in the oral cavity, it has been noted in the lip, cheek, tongue, mandible, and palate. It has been suggested that the etiology of AL is hamartomatous. Hemangioma, leiomyoma, neurilemmoma, myxolipoma, and Kaposi's sarcoma must be considered in differential diagnosis. AL is subdivided, and can be infiltrating and noninfiltrating. The differentiation between the noninfiltrating and infiltrating forms was based on the presence of a complete capsule and rare recurrences in the former, and partial or no capsule with recurrences in the latter. The diagnosis is based on both the clinical and histological features. Microscopically, AL is characterized by mature adipocytes, interspersed connective tissues with vascular vessels containing fibrin thrombi, and mast cells infiltrations. These features distinguish it from the usual lipoma.

Materials and methods: The authors describe the clinical and histological features of a noninfiltrating angiolipoma of the cheek excised with KTP laser (SmartLite®, DEKA, Italy) in a 66-year-old female patient. Clinical examination showed a soft, mobile, and rilevate mass, of ∼2×1.5 cm into the right cheek. The intervention was executed with a mucosal preservation technique. After local anesthesia without adrenaline, the lesion was exposed in the incisional phase at parameters 2 W in continuous wave (CW) and then excised at 2 W in pulsed wave (T on 100 ms, T off 100 ms). Finally, resorbable suture points were applied for aesthetic reasons.

Results: Follow-up after 7 and 30 days did not show any complication, the healing occurred perfectly, and the histological examination reported the diagnosis of AL.

Conclusions: AL of the cheek is very rare, but when it appears, it requires surgical excision; KTP laser, with its surgical properties, represents a very valuable surgical aid.

P-33. PERIAPICAL INFECTION, IMMATURE TOOTH AND Er:YAG ASSISTED APEXIFICATION

Introduction: Periapical infection in permanent immature teeth may represent a strict health problem. The aim of this clinical case report is to demonstrate that Er:YAG laser may help in the healing process.

Clinical report: A 9-year-old boy presented a post-traumatic periapical lesion on tooth 21/first maxillary permanent immature incisor.The case history revealed a dental trauma-fracture of the enamel and the dentin without exposure of the pulp, restored via a composite resin 6 months ago, followed by a pulp necrosis, chronic periapical inflammation, and an periapical abscess. Several different dental practitioners provided unsuccessful endodontic treatment plus access cavity closure, which was followed by an abscess. During the first consultation, radiolucency was observed in the periapical region and the treatment was initiated following different steps: access cavity redesign, root canal preparation (NaOCl), decontamination via Er:YAG laser 200 mJ, 10 Hz, sapphire tip diameter 0.2 mm inserted until 6 mm inside the root canal two times 5 sec each, plus NaOCl as irrigating solution. The theoretical fluence was 636.94 J/cm². Temporary root canal filling was conducted with Ca(OH)² cement.The same protocol canal filling with Ca(OH)² paste was applied after 3 days, 1 week, 1 month, and each month thereafter until the 8th month. Symptoms disappeared after first application of Er:YAG laser, in synergy with NaOCl as irrigating solution plus filling of Ca(OH)² paste. Once radiolucency disappeared and apexification was observed, then the root canal was filled using the conventional method.

Conclusions: Er:YAG laser, in synergy with NaOCl plus Ca(OH)² may help to heal such a complex clinical endodontic problem.

P-34. PERIPHERAL GIANT CELL GRANULOMA. A REPORT OF TWO CASES TREATED BY DIODE LASER

Aim: Peripheral giant cell granuloma is a relatively uncommon oral lesion, arising mainly from the connective tissue of the gingiva, periodontal membrane, or periosteum of alveolar ridge, or in response to local irritation. Initially, similar central lesions of the jaw were referred to as “reparative lesions”. Since the reparative response was quite rare, the term “peripheral giant cell granuloma” is currently preferred and universally accepted. The aim of this work is to describe two cases of oral peripheral giant cell granuloma excised by diode laser.

Materials and methods: Two male patients, 12 and 60 years old, were referred to our observation because of a brown swelling on gingival mucosa. The swelling was painless, soft and sessile. A diode laser 808 nm was used for the excision, by the same surgical technique at 2 W in continuous wave mode.

Results: In both cases, a bloodless surgery was performed. Follow-up at 7, 21, and 60 days showed a complete healing and the absence of any recurrence. Histological examination confirmed the diagnostic suspect, peripheral giant cell granuloma.

Conclusions: Diode laser allowed a decisive surgery, with the absence of suture, a bloodless field, and relative speed and ease of excision.

P-38. THE APPLICATION OF CO₂ AND Er:YAG LASER FOR TREATMENT OF GINGIVAL PIGMENTATION

Aim: Melanin pigmentation is an aesthetic problem, especially when it occurs in the facial part of the gingiva, and can be seen during speech and smiling. There are various procedures for removal of melanotic areas, such as scalpel surgery, laser surgery, cryosurgery, and electrosurgery. The aim of this study was to assess the bleeding and pain after using CO₂ and Er:YAG laser for the depigmentation of oral mucosa.

Materials and methods: Ten patients with melanin-pigmented gingival sites on the anterior part of two jaws were selected. The treatment was performed with the patient under local anesthesia. The lesions from the midline were divided into two parts (left and right). Then, the left and right part of lesion were randomly treated by CO₂ or Er:YAG laser. The CO₂ laser with wavelength of 10,600 nm with average power of 7.2 W (frequency 20 Hz) and Er:YAG laser (2940 nm) with power of 2 W and frequency of 20 Hz were applied for this procedure.

Results: In both the CO₂ and Er:YAG laser groups, the region of surgery did not bleed (dry surgery) and the patients had no complaints of pain or sensitivity.

Conclusions: It seems that laser can be an alternative device for eliminating gingival pigmentation because of its efficacy in treatment of superficial benign pigmented lesions and decreased trauma for the patient, and its ease of use.

P-43. USE OF THE LASER IN ORAL PATHOLOGY: EMPIRICISM OR CLINICAL EVIDENCE?

Aim: The use of the laser has entered daily clinical practice we are passed the first uncertain experiences to arrive at repeatable scientific certainties. We are, therefore, finished with the empiricism (from the Latin word for “experiment,” that is, founded upon data contingent upon experience, extraneous to scientific rigor, and for this reason unadvisable) and have moved on to the evidence (from the Latin “perspicuitas” of “cognoscere,” that is, immediate and total visibility and comprehensibility). From an initial confusion and from legitimate doubts on the use of these revolutionary methodic we have found therapeutic protocols applicable to different fields of oral pathologies. It is our intention to report some pathological forms as the burning syndrome, the precancerous lesions, the ulcerations of the oral mucosa, the lichen planus, the epulis fibrous angiomatosis; a case of lingual resection with notable delay to the processes of recovery.

Materials and methods: The use of diodes lasers with three different fiber optics 200, 400, and 600 have become part of our operating routine endodontics, periodontics, and the oral surgery, for >6 years. In the last 2 years we have used, initially with a lot of caution, low-level laser therapy (LLLT) in cases of precancerosis and the burning syndrome that appeared resistant to other traditional pharmacological therapies. The results have been amazing; the mechanism of action of the laser would seem tied to the activation of the cytokines. Personally, being neither a researcher nor a physicist, I am not able to explain the phenomenon, but it is certain that in the clinic the results are evident.

Results: All the treated cases, except for two elderly subjects with burning syndrome, quickly improved, and two patients with serious precancerous lesions, already on the operating list for surgical intervention, entirely recovered. All the treated cases, although heterogeneous, showed good healing after the treatment.

Discussion: The laser light–LLLT–in skilled hands is a valid help in pathologies, also rare, of the oral cavity. In our practice we have used this technique on the tongue and on the oral mucous and perioral tissues, effecting some definitive recoveries with notable benefits for the patients, and avoiding notable and dangerous complications.

Conclusions: We can conclude by saying that the use of the laser in oral pathology is a reality, as in other fields of odontostomatology.

P-45. DENTAL BLEACHING: LASER-ASSISTED TECHNIQUES. A REVIEW OF THE LITERATURE

Background: In daily practice the request for dental bleaching has become increasingly frequent. The introduction of the new laser devices opens a new treatment field to add the advantages of laser-assisted bleaching to the conventional method, while remaining a safe and reliable technique. The aim of this review is to specify the role of different laser systems applied to the bleaching of teeth and to understand which wavelengths are more suitable for laser-assisted dental bleaching.

Methods: MEDLINE and PubMed were searched from 2004 through 2010 using the key words teeth bleaching, Er:YAG, Nd:YAG, diodes, KTP. Additional general articles were included in this review. Sixty-six articles were retrieved and reviewed.

Results: It was shown that Nd:YAG, CO₂, Er:YAG, and argon ion laser did not add benefits to the bleaching process, and moreover, iatrogenic effects easily appeared. In contrast, an increase of the yield of the bleaching mechanism was found when using KTP and diode lasers, making those ones in laser-assisted bleaching techniques. However, sensitivity was found when using diode laser-assisted bleaching.

Conclusions: The studies reveal that the selective activation of the rhodamine pigment added to the bleaching gel by the KTP laser, can selectively increase the activation of the bleaching gel, increasing the yield of the bleaching process, and avoiding the most common side effects. More standardized studies are needed to determine which laser system is more appropiate to increase the yield of the bleaching mechanism. Clinical studies are needed to prove the efficacy and reliability of the KTP laser-assisted bleaching.

P-47. SOFT-TISSUE MANAGEMENT USING DIODE LASER IN ONCOLOGIC PATIENTS: A CASE REPORT

Aim: One major challenge in treating head and neck oncologic patients is to achieve an acceptable recovery of physiologic functions compatible with complete tumor excision. In oral cancer, a multidisciplinary approach is required, often including prosthetic rehabilitation. However, after tumor resection, some patients present a surgically altered anatomy incompatible with prosthetic rehabilitation, unless soft-tissue recontouring is performed. The aim of this study was to evaluate the possibilities and advantages of using diode laser (λ: 980 nm, Wiser®, Doctor Smile, Italy) in a postoncologic patient requiring prosthetic rehabilitation.

Materials and methods: A 72-year-old woman who had undergone partial resection of the tongue for squamous cell carcinoma ∼15 years earlier, was referred to our department for prosthetic rehabilitation. The patient presented partial mandibular edentulism, defects in tongue mobility, and a bridge of scar tissue connecting one side of the tongue to the alveolar ridge. A diode laser (λ: 980 nm, Wiser®, Doctor Smile, Italy), at parameters of 2 W operating in continuous wave, was used to remove the fibrous scar tissue resulting from the hemiglossectomy, and to perform deepening of both the lower buccal fornix and the sublingual sulcus, thus re-establishing proper vestibular depth and ridge anatomy allowing an implant supported overdenture. Clinical observations were performed at 7, 14, 21, and 28 days.

Results: During the procedure, the surgical site presented only minimal bleeding, guaranteeing excellent operative visibility. No sutures were required. No pain or particular discomfort has been reported by the patient in the postoperative period. Satisfying re-epithelialization has been observed at 14 days and has been completed by 28 days.

Conclusions: The diode laser 980 nm was demonstrated to be a valuable aid in this particular case of preprosthetic surgery. The clinical outcome of the case herein presented is in accordance with literature findings about the use of diode laser in oral soft tissue surgery.

P-49. THE USE OF Nd:YAG LASER IN THE TREATMENT OF ANGIOMAS IN PATIENTS WITH STURGE–WEBER SYNDROME

Aim: The aim of the present study is to verify and prove the effectiveness of Nd:YAG laser in the treatment of patients with Sturge–Weber syndrome, who are at increased risk of hemorrhage during gingivectomy for angioma removal.

Materials and methods: Laser surgery is technically based on photocoagulation and photoablation, which vaporize soft tissues cells through a monochromatic, coherent beam of light. The effectiveness of Nd:YAG laser was measured by treating several patients with Sturge–Weber syndrome.

Results: Besides improving the postoperative follow-up and reducing the incidence of angiomas, Nd:YAG laser proved advantageous in improving surgical field visibility and reducing the time of surgery, compared with traditional procedures.

Conclusions: In light of the studies in the literature, Nd:YAG laser, with its strong hemostatic properties, is the right choice in the surgical treatment of patients at great risk of hemorrhage, such as patients with Sturge–Weber syndrome.

P-50. DIODE LASER THERAPY ON PERIMPLANTITS USING THE PHOTOSENSITIZER TOLUIDINE BLUE: A CLINICAL COMPARATIVE STUDY

Aim: The aim of this prospective in vivo study was to compare the effects of photodynamic therapy (PDT) using a diode laser with an 810 nm wavelength together with a toluidine blue O application (TBO) to the effects of conventional explorative surgical therapy (CT) regarding reduction of anaerobic bacteria on the rough implant surfaces, into sites affected by peri-implantitis.

Methods: A total of 40 Caucasian patients (24 women and 16 men, with a mean age of 46 years), who showed clinical and radiographic signs of oral peri-implantitis, were randomly divided into two groups. Both underwent mucoperiosteal flap surgery performing scaling on implant surfaces and debridement of the granulation tissues. The CT group was then irrigated with a 0.2% chlorhexidine solution only. In the PDT group, TBO was applied inside the peri-implant sites and then irradiated with diode laser for 20 sec, repeated five times, for a total exposure length of 100 sec. Microbiological samples and inflammatory parameters were obtained before treatment, immediately after treatment, and at the 12th and 24th post-treatment weeks.

Results: After treatment of the PDT group, the total anaerobic bacterial counts showed a mean bacterial reduction of 94.45% compared with 82.64% seen in the CT group (p<0.05). Detection of Aggregatibacter actinomycetemcomitans was positive with the following distribution: 15 patients of the PDT group (15 out of 20) and 16 patients of the CT group (16 out of 20). A reduction by 2 log steps (**) was reached, respectively, in two samples of Porphyromonas gingivalis and one sample of A. actinomycetemcomitans in the PDT group. Values measured at the 12th and 24th week observations showed a gradual increase of the anaerobic bacterial counts. A. actinomycetemcomitans showed, overall, a lower bacterial counts percentage reduction (p<0.003) than did Porphiromonas gingivalis (p<0.0001) and Prevotella intermedia (p<0.0003). PDT resulted, however, in a significantly greater decrease of bleeding scores than did the CT modality (p<0.03).

Discussion: The attempt of this comparative study was to examine, in vivo, the degree of bacterial decontamination in two patient groups affected by peri-implantitis, following either PDT with diode laser (810 nm wavelength) plus photosensitization with TBO, or CT in addition to a 0.2% chlorhexidine 0.2% irrigation. The findings of the investigation indicated that the treatment of peri-implant lesions with PDT plus TBO via a diode laser technique, using an 810 nm wavelength, may result in an additional beneficial outcome compared with the CT modality, in the decontamination of anaerobic microbiota on rough titanium implant surfaces. This benefit seems to attenuate at the 3rd and 6th post-treatment months. On the other hand, PDT seems to distinctly reduce the clinical peri-implant inflammation signs at the same time, as it results in a significant reduction of the bleeding scores in comparison with the conventional technique.

Conclusions: The PDT bactericide benefit seems to be only temporarily maintained, as a partial re-colonization took place at the 3 and 6 month post-treatment evalutaions. PDT seems to distinctly reduce the clinical peri-implant inflammation signs at the same time, as it results in a significant reduction of the bleeding scores and of inflammatory exudation, in comparison with the conventional technique alone. However, further in vivo studies are needed to truly examine the influence of oral environmental variables on the PDT outcomes, before any long-term effect of the procedure can be presented.

P-52. CLINICAL EVALUATION OF THE EFFECTIVENESS OF THE Nd:YAP LASER FOR THE INITIAL TREATMENT OF PERIMPLANTITIS: A CASE REPORT

Background: Missed enhancement of results obtained by scaling and root-planing (SDP), laser-assistance in perimplantitis/ periodontitis, Neodymium-doped Yttrium aluminium perovskite (Nd-YAP) laser bactericide effect (in association with conventional endodontic irrigant) and high affinity of Nd-YAP wavelength (1340 nm) for H₂O solutions observed in the literature directed our research to a new way of treating perimplantitis.

Case presentation: The aim of this study is to evaluate effectiveness of Nd:YAP laser in treatment of perimplantitis in association with a hydrogen peroxide solution.

Materials and methods: Selected patients (male, nonsmoker, nondiabeti), with a diagnosed perimplantitis of 2.2 element, were offered a laser treatment to restore his initial perimplant condition. An Nd:YAP laser with hydrogen peroxide solution (10 vol.) was used to treat the perimplant pocket (no suppuration, bleeding on probing [BOP]+, pocketdepth 3 mm vestibular-palatal, 4 mm mesial, and 5 mm distal) after a light curettage by teflon. This treatment was divided into two sessions: the second 7 days after first. Pocket depth, BOP, prescription, microscopic analysis, and photographs were reviewed after 1 month and 6 months.

Results: One month follow-up showed no inflamed perimplant tissue (no suppuration; BOP-; pocket depth 2 mm vestibular-palatal, 2 mm mesial, and 3 mm distal; bone level stabilized, and implant neck exposed because of little retraction of perimplant tissue without edema. The same results were found after 6 month follow-up.

Conclusions: Thanks to its properties, Nd-YAP laser beam is largely absorbed in H₂O₂, emphasizing the oxygen bactericide effect against anaerobic pathogenic perimplant bacteria. Implant surface damages were avoided, and edema and after-surgery pains were minimized.

P-53. LINGUAL FRENECTOMY: A COMPARISON BETWEEN THE CONVENTIONAL SURGICAL AND LASER-ASSISTED PROCEDURES

Background: Ankyloglossia, commonly known as tongue-tie, is a congenital oral anomaly characterized by a short lingual frenulum that may contribute to feeding, speech and mechanical problems.

Case presentation: The purpose of this study is to compare the advantages of laser vis-à-vis conventional frenectomy in both the intra- and postsurgical phases.

Materials and methods: This study took into consideration two patients, 10 and 6 years old. The first one underwent a common surgical procedure. An Nd:YAP micropulsed laser device with a micropulsed wavelength of 1340 nm and power of 8 W was used for the second. The postsurgical discomfort and healing characteristics were evaluated.

Results and discussion: The results indicated that the Nd:YAP laser has the following advantages when compared with conventional frenectomy: (1) Soft tissue cutting was efficient, with no bleeding, giving a clear operative field. (2) There was no need to use sutures. (3) The surgery was less time consuming. (4) There was no postsurgical infection and no need for analgesics or antibiotics. (5) Wound contraction and scarring were decreased or eliminated.

Conclusions: Considering the above elements, it is possible to assert that laser frenectomy has a series of unquestionable advantages if compared with the conventional surgical technique.

P-54. THE USE OF LASER DIODE 810 NM IN ORAL SOFT TISSUES SURGERY: PRESENTATION OF SOME CASE REPORTS

Aim: The aim of this study is to report some cases of laser-assisted surgery, consisting of excision and vaporization of benign lesions of oral cavity,demonstrating its low percentage of morbidity and intraoperative and postoperative complications.

Materials and methods: Benign lesions of the oral cavity were selected to be treated with laser-assisted surgery. An 810 nm wavelength laser diode was used. After excisional laser biopsy or vaporization of neoformations, patients were instructed just to use scrupulous oral hygiene and local medication, to be applied three times a day, of 0.2% chlorhexidine gel. The postoperative controls were performed after 7 days.

Results: Laser-assisted surgery has a low percentage of morbidity and intraoperative and postoperative complications. Laser diode or laser semiconductor with wavelength between 810 and 980 nm is the most used; in particular, the 810 nm laser diode has a high efficacy on hemoglobin and melanin molecules and a low absorption in water, so that it has, first of all, surgical applications, and also because of optimal hemostasis control, can be used in excision and vaporization of benign lesions of oral cavity.

P-55. REJUVENESCENCE OF PERIORAL REGION BY COMBINED USE OF FILLERS AND CO₂ FRACTIONAL LASER

Aim: Fractional skin rejuvenation has gained interest since its introduction in 2003. Both nonablative and ablative lasers as well as different treatment techniques have been devised. Recent successes with CO² fractional laser combined with fillers in the rejuvenescence of the perioral region are demonstrated by the illustration of some clinical cases.

Materials and methods: A CO₂ laser was equipped with a scanner enabling it to perform fractional treatments. Four patients participated in the study. The perioral area was treated three times with 1 month intervals. Follow-up was performed 3 months after the last treatment. The patients also received infiltration of the perioral region with different kinds of resorbable fillers.

Results: All the patients gained a visible reduction of perioral wrinkles and pigmentations.

Conclusions: Aesthetics of the inferior third of the face are strictly dependent on correct morphology and chromaticism of teeth, on harmonic skin surface, and on proportionate volume of lips and jaw area. Defects of the perioral area can be related to volumetric alterations of lips, nose–cheek furrows, and jaw region, and to cutaneous alterations, such as hyperpigmentations, teleangectasia, rugosities, and elastosis. The present study demonstrates subjective improvements in wrinkles, skin texture, and mottled pigmentation after the use of fractional CO₂ combined with resorbable fillers.

P-56. SHORT LINGUAL FRENULUM SURGERY BY TWO DIFFERENT LASER WAVELENGHTS: A CLINICAL COMPARATIVE STUDY

Background: The tongue is an important oral structure that affects speech, the position of teeth, periodontal tissue, nutrition, swallowing, nursing, and certain social activities. A short lingual frenulum limits the range of motion of the tongue, impairing its ability to perform its functions. The consequences of not treating improper tongue function can also influence face development and dental therapy. Malocclusion as lateral posterior cross-bite and anterior open bite can be one of these consequences.

Objective: The objective of this study was to evaluate and compare the clinical efficiency and the performance of two different laser wavelengths for short lingual frenulectomy.

Materials and methods: Lingual frenulectomies were performed using two different wavelengths: diode Laser 940 nm 3.4 W continuous mode with fiber 300 μm PD 48 W/cm² and Er:YAG in VLP mode (1000 μs), 150–180 mJ, 8 Hz, spot size diameter 0.8 mm fluence 30–36 J/cm². During surgery and immediately after bleeding, pain or other complications were noted. Checkups were performed at 7, 14, and 28 days after surgery in order to follow and evaluate the healing process of the surgical site.

Results: Whatever the wavelength used, frenulectomies were performed in good clinical situations without any complication. None of the patients complained of any pain. In all the frenulectomies performed with diode laser, there was no bleeding. With the Er:YAG laser in all the cases of bleeding, coagulation was obtained by using a tampon with a hemostatic solution applied with pressure, or using the Er:YAG laser in defocalized mode, with a lower energy. Seven days after surgery no postoperative complications such as swelling, bleeding, or pain were observed and a thin layer of fibrin covered the treated zone. Complete healing was observed after a maximum of 4 weeks.

Conclusions: Using Er:YAG laser and diode laser, short lingual frenulectomies can be performed successfully without any real postoperative complications and with good and fast healing.

P-58. CO₂ LASER SKIN RESURFACING: TO DEBRIDE OR NOT DEBRIDE?

Aim: CO₂ laser skin resurfacing has been reported in the literature to improve both the pigmentary and textural changes associated with photoaging. The adverse affects of traditional CO₂ laser resurfacing have been well reported including scarring, hypopigmentation, and prolonged erythema.

Materials and methods: New devices are being developed to minimize these side effects, yet provide substantial results. The treatment standard for laser skin resurfacing includes aggressively wiping away the char with moist gauze before and after each pass to prevent heat buildup and lateral tissue damage from existing char. Not many studies have addressed not debriding between passes with traditional CO₂ laser.

Results: The objective was to disprove the dogma that wiping away the laser char between treatment passes is necessary. A total of 15 patients were treated over 2 years with multipass, nondebrided CO₂ laser resurfacing.

Conclusions: None of the nondebrided patients experienced significant complications. Operative times were shortened as was postlaser pain and erythema.

The authors have indicated no significant interest with commercial supporters.

P-60. THE USE OF ER:YAG LASER FOR THE TREATMENT OF BISPHOSPHONATE– AND NON-BISPHOSPHONATE–RELATED ONJ

Aim: Osteonecrosis of the jaws (ONJ), also known as “avascular necrosis” and “aseptic necrosis” is not an autonomous disease but rather the consequence of a number of local or systemic factors that can change the blood flow inside the bone and covering tissues, thus exposing bone tissue to several additional factors. Among the various risk factors there are: Local factors (radiotherapy of head and neck, dental surgical procedures involving bone); Systemic factors (bisphosphonate therapy, corticosteroid therapy, hemodialysis); Iatrogenic factors (use of arsenic derivatives, incongruous use of root canal irrigation). Currently, treatments to control this condition and alleviate and/or stop certain ONJ symptoms include antibiotics, antiseptic rinses, hyperbaric oxygen therapy, and treatment with ozone. Later intervention may be necessary to remove necrotic tissue and reduce sharp edges of damaged bone. Recently, Er:YAG laser was proposed to treat necrotic lesions of the bones in the maxillofacial area. The aim of this work was to describe clinical and therapeutic benefits obtained by the Er:YAG laser in the treatment of bisphosphonate-related and non-bisphosphonate-related ONJ.

Materials and methods: In those patients who already have developed an ONJ, surgical removal can be easily performed using Er:YAG laser, which can perform a selective and atraumatic removal of necrotic bone. The conservative-surgical approach involves the use of Er:YAG laser in focused mode, with energy parameters ranging from 190 to 250 mJ, with a frequency of 20 Hz, in VSP (Very Short Pulse) and with air and water coolant spray.

Results: The advantages observed are mainly: fewer traumatic interventions, absence of carbonization, absence of tissue debris, high versatility, speed of execution, and comfort for the patient. Er:YAG laser can help to obtain a complete covering of bone exposure, or full healing of the bony lesion, depending upon the etiology of the ONJ. Reduction of the microbial count and of local signs/symptoms can also be achieved.

Conclusions: Management of ONJ can be quite difficult; therefore, laser devices can be used to treat optimally any form of osteonecrosis regardless of the etiological factor. Our hope is that the clinical application and scientific studies on the role of Er:YAG laser in conservative surgical treatment of the osteonecrosis may continue, to reach a reproducible therapeutic protocol, individualized for each kind of ONJ. Proper diagnosis is fundamental to reach this result.