Evaluating the Efficacy of the Er,Cr:YSGG Fractional Laser Before Treatment With Triamcinolone NN Ointment in Oral Lichen Planus Lesions.

Introduction: It has been demonstrated that laser technology can enhance topical drug absorption. This study aimed to determine the effects of Er,Cr:YSGG laser radiation before the application of topical corticosteroids in the healing of oral lichen planus. Methods: In this double-blind split-mouth clinical trial, 32 lesions were chosen from eight patients affected by oral lichen planus (OLP). The oral lesions were randomly categorized into two groups. The first group had topical treatment with triamcinolone NN ointment and the second group had laser radiation (Er,Cr:YSGG) for eight weeks before starting the ointment. For each lesion, the irritating level based on the VAS score, the lesion level based on the Thongprasom scale score, and the healing time were measured, and the collected data were analyzed by the Friedman test and the Wilcoxon's statistical test. Results: The mean healing time based on the verbal analog scale (VAS) score was not significantly different between the two treatment groups (P>0.05). The mean healing time based on Thongprasom scale scores did not show any significant difference between the two treatment groups (P>0.05). Conclusion: The application of the Er,Cr:YSGG laser before treatment with triamcinolone NN ointment did not show any advantage for the average healing time compared to a medicine regimen with only triamcinolone NN ointment.

The efficacy of low-level diode laser versus laser acupuncture for the treatment of myofascial pain dysfunction syndrome (MPDS).

BACKGROUND: Myofascial pain dysfunction syndrome (MPDS) is the most common type of temporomandibular disorder. This study compared the efficacies of low-level diode laser therapy (LLLT) and laser acupuncture therapy (LAT) in the treatment of MPDS. METHODS: This double-blind randomized controlled clinical trial included 24 patients with MPDS who were randomly divided into two equally sized groups. Patients in the LLLT group received 12 sessions of low-level diode laser irradiation applied to the trigger points of the masticatory muscles during 1 month. The same protocol was also used in the LAT group according to the specific trigger points. We measured pain intensity and maximum mouth opening in both groups at baseline, during treatment, and 2 months after treatment completion. RESULTS: The pain intensities decreased from 6.58 ± 1.31 to 0.33 ± 0.65 and from 7.08 ± 1.37 to 0 in the LLLT and LAT groups, respectively. The maximum mouth openings increased from 32.25 ± 8.78 mm to 42.58 ± 4.75 mm and from 33 ± 6.57 mm to 45.67 ± 3.86 mm in the LLLT and LAT groups, respectively. Pain intensity (P = 0.839) and level of maximum mouth opening (P = 0.790) did not differ significantly between the groups. CONCLUSION: Our results showed similar efficacy between LLLT and LAT in the treatment of MPDS signs and symptoms.

Efficiency of Erbium-Doped Yttrium Aluminum Garnet Laser in Debonding Cemented Glass Fiber Posts: an in vitro Study.

STATEMENT OF THE PROBLEM: The efficacy of erbium-doped yttrium aluminum garnet (Er; YAG) laser on the debonding properties of certain post materials has remained largely unexplored. PURPOSE: This study aimed to investigate the effect of Er; YAG laser irradiation on debonding of cemented glass fiber posts in root canal treated teeth. MATERIALS AND METHOD: In this in vitro study, forty root canal treated mandibular premolar teeth were used in this study. Glass fiber posts were bonded using Panavia F 2.0 cement in the root canal space, and samples were divided into two groups. In the test group, samples were exposed to laser radiation of 7W, 350mJ, frequency of 20Hz and discontinued washing spray. In the control group, samples were left untouched. In each group, samples were sectioned into 1.5mm thick slices from the coronal, middle, and apical thirds of the root (N=120). Tensile bond strengths were evaluated using the push-out test and the failure patterns were evaluated using scanning electron microscopy (SEM). To compare the laser and non-laser groups at each location, independent sample t test was applied, and to compare bond strength between the locations in each group, one-way ANOVA and Tukey's HSD post hoc was applied. RESULTS: A significant difference in tensile strength was observed between the laser-irradiated group and control group; tensile bond strength was much higher in the control group (p<0.001). The highest frequency of fractures was observed at the cement-dentin interface. Given the used parameters, complete debonding was not achieved in the laser-irradiated group. CONCLUSION: Laser radiation reduced the bond strength of glass fiber posts to resin cement without complete debonding.

The effectiveness of home-use photobiomodulation toothbrush for treating dentin hypersensitivity: A pilot study.

BACKGROUND AND AIMS: Dentin hypersensitivity is a frequent oral condition among patients suffering from gingival recession. Recent studies have suggested that photobiomodulation has the potential to reduce inflammation and relieve pain. The present study aims to assess the effectiveness of a new design of photobiomodulation toothbrush with specific irradiation parameters as a homecare device in treating dentin hypersensitivity and to compare its therapeutic effect with that of fluoride varnish. MATERIALS AND METHODS: Thirty patients with gingival recession and dentin hypersensitivity were selected and randomly assigned to three groups of equal size: fluoride varnish, photobiomodulation, and the combination. Dentin pain and hypersensitivity were measured using visual analog scale (VAS) by two distinct tests: the contact test with a periodontal probe and the air blast test on the areas of gingival recession and denuded root; once at baseline and again one month after the initial application of treatments. Laser irradiation was carried out at the wavelength of 660 nm in CW with an output power of 40 mW for 30 seconds per spot (1.2 J per spot, 6 J/cm2 energy density, and 200 mW/cm2 power density), perpendicularly to denuded root surfaces in non-contact mode. RESULTS: A significant reduction in dentin pain and hypersensitivity was observed in all three groups. However, the reduction was significantly greater in the combination group. CONCLUSION: At-home treatment of dentin hypersensitivity with photobiomodulation toothbrush is a convenient, safe, and effective method for the management of dentin hypersensitivity.

Effect of Diode Laser (810 nm) Irradiation on Marginal Microleakage of Multi-mode Adhesive Resins in Class V Composite Restorations.

Introduction: Some studies have shown that laser irradiation on unpolymerized adhesives can improve composite-dentin adhesion. The aim of the present study was to evaluate the effect of the diode laser (810 nm) on the microleakage of multi-mode adhesive systems at enamel and dentin margins of composite restorations. Methods: Classic class V boxes were prepared on 48 sound premolar teeth and randomly divided into 6 groups (n=16). In the control groups, Scotchbond Universal (SBC), G-Premio (GBC), and Ambar U (AMC) were used by a self-etch mode. In the test groups (SBL, GBL, ABL), the 810 nm diode laser was irradiated (1 W) for 10 seconds before the polymerization of the adhesive. The boxes were restored by the resin composite. After finishing and polishing, the samples were thermocycled (5°C to 55°C) for 1000 cycles and then immersed in 0.1% methylene blue dye (48 hours). Dye penetration through the gingival and occlusal margins was measured by Stereomicroscope. The data were analyzed at the 5% significance level using Kruskal-Wallis and Mann-Whitney U tests. Results: Significant differences were found between the control and test groups (P < 0.05). The occlusal margins of the SBL and GBL groups and the cervical margin of the SBL group exhibited the lowest microleakage (P < 0.05). The AM control group showed maximum microleakage at cervical and occlusal margins. Conclusion: The irradiation of the 810 nm diode laser on the unpolymerized universal adhesive systems in a self-etch mode caused a significant reduction in enamel and dentin marginal microleakage of composite restorations.

The Effect of Er:YAG Laser Irradiation Combined With Fluoride Application on the Resistance of Primary and Permanent Dental Enamel to Erosion.

Introduction: Erosion is an important cause of tooth mineral loss. The combined use of lasers and fluoride has been introduced as a novel modality for the prevention of enamel demineralization. This study aimed to assess the effect of Er:YAG laser combined with fluoride application on primary and permanent enamel resistance to erosion. Methods: Eighty enamel specimens of permanent (n=40) and primary (n=40) molars were prepared and randomly assigned to 4 groups: C-control (no pretreatment), F-acidulated phosphate fluoride (APF) gel, FL-APF gel application followed by Er:YAG laser irradiation, and LF-Er:YAG laser irradiation followed by the application of APF gel . The specimens were then submitted to pH cycling using Coca-Cola (pH=2.4). Enamel micro-hardness was measured using the Vickers microhardness tester before pretreatment and after the erosive process. The collected data were analyzed using the Kolmogorov-Smirnov test, two-way ANOVA and repeated measures ANOVA. Results: The micro-hardness of both permanent and primary enamel specimens significantly decreased after the erosive process (P < 0.05). In the permanent enamel specimens, the greatest reduction in micro-hardness was noted in groups C and F, while the least reduction was noted in group FL. However, these differences were not statistically significant (P > 0.05). In the primary enamel specimens, the greatest reduction in micro-hardness was noted in groups C and LF, while the least reduction was noted in group F. These differences were not statistically significant (P > 0.05). Conclusion: Within the limitations of this study, Er:YAG laser irradiation combined with fluoride application could not prevent erosion in permanent and primary enamel during the erosive process.

The Clinical Evaluation of the Effects of Low-Level Laser Therapy on the Donor and Recipient Sites of the Free Gingival Graft: A Case Series.

Introduction: Free gingival grafting is among the most foreseeing procedures for increasing the zone of keratinized attached gingiva and enhancing soft tissue around the teeth and dental implants. Nowadays low-level laser therapy (LLLT) is a promising approach in providing patients with more pleasing results in terms of esthetics and comfort. This study aims to investigate the effects of LLLT on gingival recessions treated with free gingival graft (FGG). Methods: This case series was conducted on 12 individuals requiring a bilateral gingival graft in the mandibular region. There was a 30-day interval between the two operations. The test side was selected randomly and irradiated by a low-level laser (LLL) just before surgery. The patients did not know which side was irradiated. LLLT was applied to the donors' as well as recipients' site immediately after the operation and 48 hours later. The patients were instructed to record their post-operative pain in a visual analogue scale (VAS) 3 and 24 hours and 7 days after the surgical procedure. The clinical photographs were taken immediately and 30 days after surgical treatment were graded by three experienced periodontists for color matching to adjacent tissues. Results: Ten individuals could finish the study. The test group presented significantly better shade matching and wound healing at the palatal donor site on days 7, 14 and 21. There was a significant reduction in post-operative pain after 24 hours (P = 0.007). No statistically significant difference was found between both groups in terms of clinical periodontal indices. Conclusion: LLLT could reduce post-operative pain 24 hours after surgical treatment. Furthermore, the application of LLLT could improve the donors' site healing and the recipients' site color matching.

Effect of one and two sessions of antimicrobial photodynamic therapy on clinical and microbial outcomes of non-surgical management of chronic periodontitis: A clinical study.

Background: This study aimed to compare the effect of one and two sessions of antimicrobial photodynamic therapy (aPDT) as an adjunct to scaling and root planing (SRP) on clinical and microbial parameters in patients with chronic periodontitis. Methods: This study was conducted on 20 patients. The dental quadrants of patients were randomly assigned to SRP at baseline (group 1), SRP at baseline and one month (group 2), SRP plus aPDT at baseline (group 3) and SRP plus aPDT at baseline and one month (group 4). Probing depth (PD), clinical attachment level (CAL) gain, and bleeding on probing (BoP) were measured at baseline, and one and three months later. F. nucleatum counts were determined by PCR. ANOVA was used for the comparison of these variables between the groups. Results: In all the groups, PD reduction and CAL gain increased significantly at 1- and 3-month intervals compared to baseline (P=0.001). At three months, the difference in PD between groups 1 and 3 was statistically significant (P=0.014). CAL gain between groups 2 and 4 at one month (P=0.016) and three months (P=0.001) wasstatistically significant. Reduction in F. nucleatum counts was not significant between the four study groups (P>0.05). Conclusion: A combination of two sessions of aPDT and SRP could improve CAL gain; however, further long-term studies are necessary in this regard.

Effect of 810 nm diode laser on physiologic gingival pigmentation.

BACKGROUND AND AIMS: Physiologic gingival pigmentation (PGP) is the most common type of gingival pigmentation causing esthetic concerns particularly in gummy smile patients. Laser therapy is an effective and noninvasive treatment modality for such patients. This study aimed to evaluate the efficacy of diode laser for treatment of PGP. SUBJECTS AND METHODS: This quasi-experimental study (one-group pretest-post-test design) was conducted on 20 patients complaining of gingival melanin pigmentation. The gingiva of the anterior segment of the arch was ablated with 810 nm diode laser until the entire visible pigmentation was removed. Clinical observations for the intensity of pigmentation were made at baseline, one month and three months, postoperatively. Data were analyzed using SPSS and Friedman test. RESULTS: Preoperatively, the mean score of gingival melanin pigmentation in the maxilla and mandible was 2.95. At one month postoperatively, the mean scores of the maxilla and mandible were 1.53 and 1.55, respectively. After three months, the mean rank of scores of the maxilla and mandible was 1.53 and 1.50, respectively. The difference between the pre- and postoperative mean scores was statistically significant (P < 0.001). CONCLUSION: Diode laser therapy is an effective and minimally invasive modality for gingival depigmentation. But further investigations with long-term follow ups are warranted in this respect.

Gingival depigmentation by Er,Cr:YSGG laser and diode laser: a split mouth, clinical trial study.

BACKGROUND AND AIMS: The Aim of this study was to evaluate the effectiveness of Diode laser and Er,Cr:YSGG laser ablation on the treatment of physiologic gingival melanin hyperpigmentation. MATERIALS AND METHODS: This research design was split mouth, double blind, and clinical trial. The power of the diode laser was set at 1 W, fiber 320 µ, irradiation mode: continuous-wave with treatment mode of contact tip and Er,Cr:YSGG laser (2780 nm) was set at 100 MJ, frequency of 15 Hz, total power of 1.75 W, 10% water and 20% air. Bleeding, pain, healing, Dummett oral pigmentation index (DOPI) and Hedin melanin score changes and repigmentation were assessed. Patients were followed for 6 months. RESULTS: A total number of 14 patients were involved in this study. There were statistically significant differences in reduction of DOPI and Hedin melanin score in each treatment groups separately while diode laser group had better results (P < 0.0001). There was no statistically significant difference between groups in terms of repigmentation. There was more pain in diode laser group (P < 0.0001) and there was more bleeding in Er,Cr:YSGG laser group (P = 0.0156). Gingival healing was more in Er,Cr:YSGG laser group (P < 0.0001). CONCLUSION: Diode laser had more efficiency for reduction of DOPI and Hedin melanin index scores.

Laser Assisted Treatment of Extra Oral Cutaneous Sinus Tract of Endodontic Origin: A Case Report.

Introduction: Sinus tract (or fistula) is a common manifestation of pulpal necrosis with periapical pathosis that requires conventional or rarely surgical- endodontic treatment in order to heal. It is mainly identified intraorally and in rare cases manifestation is extra orally, which may frequently be misdiagnosed with cutaneous lesion and incorrectly treated. New technologies such as lasers have been developed as adjuncts to standard endodontic antimicrobial procedures in order to increase the success rate of endodontic therapy while complying with the desire of saving a natural tooth. Case Presentation: Herein, we present a clinical case of extra oral sinus tract with periodic pus drainage that was successfully treated by combining conventional endodontic therapy, intra canal photodynamic therapy (PDT), extra oral low level laser therapy (LLLT) and laser treatment for extra oral fistula. Conclusion: Treatment of the odontogenic lesion among with the extra oral lesion was an ingenious and successful technique which was achieved via laser technology and winded up to patient's consent and satisfactory results.

Comparison of Er:YAG Laser and Hand Instrumentation on the Attachment of Cultured Human Gingival Fibroblasts to Periodontally Involved Root Surfaces.

Introduction: The present study compared the effects of erbium-doped yttrium aluminium garnet (Er:YAG) laser and hand instrumentation on the attachment of human gingival fibroblast (HGF) cells to periodontally involved root surfaces. Methods: A total of 40 tooth specimens were collected and treated in four distinct groups: scaled and root planed with hand instruments, scaled with Er:YAG laser, treated with a combination of hand instruments and Er:YAG laser and non-treated control group. The attachment and proliferation rate of HGF were assessed using MTT assay and scanning electron microscope (SEM) examination was used for cell morphological evaluation. Results: The MTT (3-[4, 5-dimethylthiazol-2-yl]-2, 5 diphenyl tetrazolium bromide) assay showed significant decrease in HGF cell viability in both hand instruments only and combination treated teeth specimens compared to control specimens (P<0.05), 24 hours after cell seeding. However, at time 48, the cell viability of attached cells in these 2 treated groups was almost similar to control. In contrast, at 24 and 48 hours after cell seeding, viability of attached cells was higher than control in Er:YAG laser treated only specimens (P<0.05). According to SEM study, the laser treated specimens showed more surface roughness. Conclusion: Er:YAG laser increased attachment and proliferation of HGF cells in comparison to the hand instruments method.

Management of Post Endodontic Retreatment Pain With Low Level Laser Therapy.

Introduction: Pharmacotherapy with analgesics and non-steroidal anti-inflammatory drugs has been traditionally used to relief post-operative pain of endodontic treatments. However, due to the side effects reported for these drugs, some efforts have been made to decrease the post-operative pain of the endodontic treatments through laser irradiation. The present study aimed to evaluate the effects of low level laser therapy (LLLT) on the reduction of pain after root canal retreatment. Methods: In this clinical trial, 61 patients requiring endodontic retreatments in posterior teeth were selected. A single visit endodontic retreatment was performed. After biomechanical preparation, low level laser was irradiated to the buccal and lingual mucosa overlying the apices of the target tooth in the experimental group. In the control group patients received placebo laser to eliminate the probable psychological effects of laser. Laser irradiation was done with a single dose of 808 nm wavelength (Whitening Lase II- Laser DMC, Samsung, Korea) with 100 mW power, and dose of 70 J/cm2 for 80 seconds. Pain severity was recorded before, immediately after and 4, 8, 12, 24 and 48 hours after the treatment by visual analogue scale (VAS). The pain scores were statistically analyzed by chi-square test between 2 groups. The effects of different variables on the post-operative pain experience were also studied by means of Logistic regression. Results: Pain scores decreased significantly through time until 48 hours after treatment. No significant differences were observed between the 2 modalities regarding pain scores at any time. According to regression analysis, pain severity scores were lower in the laser-irradiated specimens than control groups (OR = 5.69); however, this difference was not statistically significant. Consumption of analgesics after the treatment had significant effect in decreasing post-operative pain experience (OR = 56) while factors of age, gender, laser irradiation, pre-treatment pain scores and education level did not. Conclusion: Low level laser irradiation had limited effects to decrease pain associated with the endodontic retreatments in the first and second molars; however, more studies are required to assess the effects of different parameters of low level laser in this regard.

A comparison of the antibacterial activity of the two methods of photodynamic therapy (using diode laser 810 nm and LED lamp 630 nm) against Enterococcus faecalis in extracted human anterior teeth.

BACKGROUND: Failure of endodontic treatment is usually due to an inadequate disinfection of the root canal system. Enterococcus faecalis has been widely used as a valuable microbiological marker for in-vitro studies because of its ability to colonize in a biofilm like style in root canals, invading dentinal tubules and resistance to some endodontic treatments. The aim of this study was to investigate the antibacterial effects of two methods of photodynamic therapy using a light emitting diode lamp (LED lamp, 630 nm) and a diode laser (810 nm) on E. faecalis biofilms in anterior extracted human teeth. METHODS: Fifty six single-rooted extracted teeth were used in this study. After routine root canal cleansing, shaping and sterilization, the teeth were incubated with E. faecalis for a period of two weeks. Teeth were then divided into two experimental groups (nu=23) and two control groups (nu=5). Teeth in one experimental group were exposed to a diode laser (810 nm), and in the other group samples were exposed to a LED lamp (630 nm). Intracanal bacterial sampling was done, and bacterial survival rate was then evaluated for each group. RESULTS: The Colony Forming Unit (CFU) in LED group (log10 CFUs=4.88±0.82) was significantly lower than the laser group (log CFUs=5.49±0.71) (p value=0.021). CFUs in positive control group (Log10 CFUs=10.96±0.44) were significantly higher than the treatment group (p˂0.001). No bacterial colony was found in negative control group. CONCLUSION: The results of this research show that photodynamic therapy could be an effective supplement in root canal disinfection. PDT using LED lamp was more effective than diode laser 810 nm in reducing CFUs of E. faecalis in human teeth.

Low Level Laser Therapy Versus Pharmacotherapy in Improving Myofascial Pain Disorder Syndrome.

INTRODUCTION: Temporomandibular disorders (TMD) lead to masticatory muscle pain, jaw movement disability and limitation in mouth opening. Pain is the chief complaint in 90% of the TMD patients which leads to disability and severe socioeconomic costs. The purpose of this study was to evaluate the therapeutic effects of low level laser therapy (LLLT) compared to pharmacotherapy with NSAIDs (naproxen) in myofascial pain disorder syndrome (MPDS). METHODS: In this randomized controlled clinical trial, 40 MPDS patients were divided into two groups. One group received naproxen 500 mg bid for 3 weeks as treatment modality and also had placebo laser sessions. The other group received active laser (diode 810 nm CW) as treatment and placebo drug. Pain intensity was measured by visual analogue scale (VAS) and maximum painless mouth opening was also measured as a functional index every session and at 2 months follow up. Data was collected and analyzed with SPSS software. Independent t test was used to analyze the data. A P < 0.05 was considered significant. RESULTS: Low level laser caused significant reduction in pain intensity (P < 0.05) and a significant increase in mouth opening. In naproxen group neither pain intensity nor maximum mouth opening had significant improvement. Pain relief, in subjective VAS was observed in third session in LLLT group, but did not occur in naproxen group. Maximum mouth opening increased significantly in laser group compared to the naproxen group from the eighth session. CONCLUSION: Treatment with LLLT caused a significant improvement in mouth opening and pain intensity in patients with MPDS. Similar improvement was not observed in naproxen group.

Shear Bond Strength of Orthodontic Brackets to Tooth Enamel After Treatment With Different Tooth Bleaching Methods.

BACKGROUND: Bleaching treatments decrease shear bond strength between orthodontic brackets and teeth; although definite results have not been reported in this regard. OBJECTIVES: This study determined the effects of different bleaching protocols on the shear bond strength of orthodontic brackets to teeth. MATERIALS AND METHODS: This experimental study was performed in Iran. Forty-eight extracted human premolars were randomly assigned into four groups. In the control group, no bleaching treatment was performed. In groups 2 - 4, the bleaching procedures were performed using carbamide peroxide 45%, carbamide peroxide 20% and diode laser, respectively. Two weeks later, brackets were bonded to teeth and thermocycled. The shear bond strengths of the brackets to the teeth were measured. Data was analyzed by one-way ANOVA and Dunnett post-hoc test. RESULTS: Shear bond strength of the brackets to the teeth were 10.54 ± 1.51, 6.37 ± 0.92, 7.67 ± 1.01 and 7.49 ± 1.19 MPa, in groups 1 - 4, respectively. Significant differences were found between control group and all other groups (P < 0.001); and also between groups 2 and 3 (P < 0.05). No significant differences were found between the other groups. CONCLUSIONS: The bleaching procedures using 20% carbamide peroxide and 45% carbamide peroxide and diode laser significantly decreased shear bond strength of brackets to the teeth. 45% carbamide peroxide had a more significant effect on bond strength compared to 20% carbamide peroxide. The difference in bond strength was not significant between laser group and either carbamide peroxide groups.