Comparison of the Effects of High-Power Diode Laser and Electrocautery for Lingual Frenectomy in Infants: A Blinded Randomized Controlled Clinical Trial.

The aim of the study was to evaluate the release of the lingual frenulum through frenectomy in newborns zero to 90 days of age who breastfed and had diagnosis of ankyloglossia with an indication for surgery, comparing two methods: electrocautery and a high-power diode laser. Fifty-seven patients were randomly allocated to two groups (23 submitted to electrocautery and 34 submitted to a high power diode laser). Tongue movements were evaluated based on a clinical assessment and using the Bristol Tongue Assessment Tool (BTAT) before and 15 days after the surgical procedures. The visual analog scale was administered to the mothers on the same occasions for the measurement of pain during breastfeeding. Both groups had an increased BTAT score (favorable outcome) at the post-surgical evaluation, but the anterior third of the tongue was not always free to enable the movements necessary for lingual functions. It is fundamental for surgeons to have skill and in-depth knowledge of the equipment used to avoid accidents and complications in the region of important structures. Both techniques employed in this study were safe and effective, causing little bleeding and few postoperative complications. The group submitted to a high-power diode laser exhibited less post-surgical bleeding compared to the group submitted to electrocautery and no inflammation at the edges of the surgical cut.

Blinded, parallel and randomized clinical evaluation of in-office dental bleaching with violet LED (405-410nm).

This clinical study evaluated the effect of bleaching performed with violet LED light (405-410 nm), either combined with hydrogen peroxide (HP) gel, or not, on color change, dental sensitivity, participants' satisfaction and impact on their quality of life. A hundred participants were divided into one of the groups (n = 25): G1 - 35% HP (4 sessions, 1x/week); G2 - violet LED (4 sessions, 1x/week); G3 - violet LED (4 sessions, 2x/week); G4 - hybrid technique (violet LED + 35% HP; 4 sessions, 1x/week). Color evaluation was performed with colorimetric tests (objective and subjective), before, 14 days and 3 months after completion. Additionally, satisfaction with treatment, impact on quality of life (OHIP-14) and dental sensitivity were recorded. The data were submitted to statistical analysis, considering a significance level of 5%, with the exception of the data from the questionnaire on satisfaction (descriptive analysis). Two-way ANOVA and Tukey tests showed that there was no difference between color variation resulting from techniques used in G1 and G4; those used in G2 and G3 did not differ and were less effective for bleaching than those of the other groups, in both subjective and objective evaluations. Regarding tooth sensitivity, subjects in G2 and G3 experienced no sensitivity, ​​while those in G4 showed lower sensitivity values than those in G1. With respect to quality of life, only subjects in G1 and G2 showed a significant positive impact. Among the evaluated techniques, the hybrid type seemed to be a good alternative, showing effective bleaching with less tooth sensitivity.

Effect of Photobiomodulation on Salivary Cortisol, Masticatory Muscle Strength, and Clinical Signs in Children with Sleep Bruxism: A Randomized Controlled Trial.

Background: The diagnosis of sleep bruxism (SB) in children is difficult due to the lack of a polysomnographic protocol for this population. Moreover, the gold standard treatment [occlusal splint (OS) therapy] has limitations, as adequate use depends on the child's cooperation. The etiology of SB may include stress factors. Salivary cortisol is a biomarker used as a noninvasive method to evaluate the response to stress. Besides physiological aspects, it is also important to investigate morphological aspects, such as masticatory muscle strength. The aim of the present study was to determine the occurrence of bite marks on the buccal mucosa in children as a complementary sign for the diagnosis of SB and investigate and the effectiveness of photobiomodulation as an alternative treatment for this condition. Methods: Seventy-six children 6-12 years of age were divided into four groups: G1-with SB and submitted to laser therapy over acupuncture points (λ = 786.94 nm, 20 sec per point, fluency = 33.5 Jcm2, energy = 1 J, number of points = 12); G2-with SB, use of OS, G3-with SB and submitted to sham laser therapy; and G4-control group without SB. Clinical signs (bite marks on buccal mucosa and headaches), bite force (BF), and salivary cortisol (biomarker of stress) were evaluated before and after treatment. Statistical analysis involved the Kolmogorov-Smirnov, Shapiro-Wilk, and analysis of variance (ANOVA) tests. Results: Bite marks on the buccal mucosa were significantly associated with SB (p < 0.001). A statistically significant difference was found between the frequency of children with headache before and after treatment in G1 (p = 0.0005) and G2 (p = 0.0001), with no significant differences between the two groups (G1 and G2). The children in G1 had lower BF on both sides compared to the other groups. In the intragroup analysis after treatment, all groups exhibited an increase in salivary cortisol levels. Conclusions: Bite marks on the buccal mucosa can be used as a complementary sign for the clinical diagnosis of SB. Children with SB responded well to photobiomodulation therapy, as evidenced by the reduction in BF and reports of headache.

Evaluation of the Preventive Effect of Photobiomodulation on Orofacial Discomfort in Dental Procedures: A Randomized-Controlled, Crossover Study and Clinical Trial.

Background: Orofacial pain has been a prevalent symptom in the worldwide population, which may cause restrictions in daily activities and, consequently, have a great impact on the well-being of affected individuals. Photobiomodulation using light sources, such as low-level laser or light emitting diodes, with different wavelengths, has been widely used in the last years, in addition to being a noninvasive, low-cost resource and reducing pain. Objective: This study aimed at evaluating the effect of photobiomodulation as a protocol treatment to prevent facial muscle discomfort after long-term clinical procedures. Methods: The volunteers were randomized and allocated as follows: laser (n = 16) and placebo (n = 16) groups, following a crossover study design. The laser parameters were as following: 786 nm wavelength, 9 J per point, and 100 mW power of 2.393 W/cm2 irradiance. The discomfort was induced by simulating a 50-min dental procedure (with bilateral mouth open), and the pain scale (assessed bilaterally), tiredness, and temperature measurement through thermography were used for analysis. Results: The results showed a significant lower pain and tiredness in the laser group. Also, the results showed a statistically significant valid temperature change between the groups at times: T1, T40, and T50. Conclusions: According to our results, photobiomodulation showed a positive effect on the face musculature in patients submitted to the treatments, reducing pain and improving the subjective perception of exertion.

Effects of the bleaching procedures on enamel micro-hardness: Plasma Arc and diode laser comparison.

BACKGROUND AND AIMS: One of the major side effects of vital bleaching is the reduction of enamel micro-hardness. The purpose of this study was to evaluate the influence of two different bleaching systems, Plasma Arc and GaAlAs laser, on the enamel micro-hardness. MATERIALS AND METHODS: 15 freshly extracted human third molars were sectioned to prepare 30 enamel blocks (5×5 mm). These samples were then randomly divided into 2 groups of 15 each (n=15): a plasma arc bleaching group (: 350-700 nm) + 35% Hydrogen Peroxide whitening gel and a laser bleaching group (GaAlAs laser, λ: 810 nm, P: 10 W, CW, Special Tip) + 35% Hydrogen Peroxide whitening gel. Samples were subjected to the Vickers micro-hardness test (VHN) at a load of 50 g for 15s before and after treatment. Data were statistically analyzed by a Mann-Whitney test (p≤0.05). RESULTS: In the GaAlAs laser group, the enamel micro-hardness was 618.2 before and was reduced to 544.6 after bleaching procedures. In the plasma arc group, the enamel micro-hardness was 644.8 before and 498.9 after bleaching. Although both techniques significantly reduced VHN, plasma arc bleaching resulted in a 22.62% reduction in VHN for enamel micro-hardness, whereas an 11.89% reduction in VHN was observed for laser bleaching; this difference is statistically significant (p<0.001). CONCLUSION: Both bleaching techniques reduced enamel micro-hardness, although the reduction is much less significant with the GaAlAs laser than with the plasma arc. Therefore GaAlAs laser bleaching has fewer harmful effects than plasma arc in respect to enamel micro-hardness reduction.

Avaliação da interface resinal dentina em restaurações classe V após condicionamento com laser de Er: YAG / Anafysis af the resinjdentin interface in class V restaratians after Er: YAG faser etching

Objetivo: O propósito deste estudo in vitro foi avaliar a interface resina f dentina de restaurações Classe V após condicionamento com laser de Er:YAG. Material e Métodos: Cento e vinte terceiros molares humanos extraídos foram divididos em oito grupos (A 1, A2, A3, M, L 1, L2, L3 e L 4) n= 15. Cavidades Classe V foram preparadas com broca na superfície vestibular. Nos grupos L 1, L2, L3 e L 4, a dentina e o esmalte foram irradiados com laser de Er:YAG (15 Jfcm2). Após o condicionamento ácido os grupos A 1, A2, L 1 e L2 foram restaurados com Prime & Bond NT® e resina composta Esthet X® e os grupos A3, M, L3 e L4 com Single Bond® e resina composta Z25()®. Os grupos A 1, A3, L 1 e L3 foram polimerizados com luz halógena e os grupos A2, M, L2 e L4 com laser de argônio. Os espécimes foram preparados para o teste de mi- croinfiltração marginal e para a análise através de microscopia eletrônica de varredura. Resultados: Houve diferenças estatisticamente significativas entre os grupos (p< 0.05). Os menores valores de microinfiltração foram encontrados nos gruposA3 (±0.40) e L4 (±0.80). As fotomicrografias dos gruposA3, L3 e L4 mostra- ram uma superfície polida e um adequado selamento entre o material e o dente. Conclusão: Este estudo sugere que um sistema adesivo composto de HEMA, etanol e água poderia ser empregado com vantagens na adesão à dentina após o condicionamento com laser de Er:YAG. No entanto, outros estudos usando diferentes formulações químicas são necessários antes de uma recomendação para uso clínico.

Objective: The aim of this study was to assess the resin f dentin interface of Class V restorations after Er:YAG laser etching. Matherial and Methods: One hundred twenty extracted human third molars teeth were divided into eight groups (A 1, A2, A3, M, L1, L2, L3 and L4) n= 15. Class V cavities were prepared with bur on the vestibular surfaces. However, in groups L1, L2, L3 and L4, dentin and enamel surfaces were irradiated with Er:YAG laser (15 Jfcm2). After acid etching groups A 1, A2, L 1 and L2 were restored with Prime & Bond NT® and composite resin Esthet X® and groups A3, M, L3 and L4 with Single Bond® and composite resin Z25()®. GroupsA 1, A3, L 1 and L3 were light cured by current visible light and groups A2, M, L2 and L4 with an argon laser. The specimens were routinely processed for the microleakage test and SEM analysis. Results: There were statistically significant differences among groups (P< 0.05). The lower microleakage values were found in groups A3 (±0.40) and L4 (±0.80). The photomicrographs of groups A3, L3 and L4 showed a smooth surface and an adequate seal between material and tooth. Conclusion: This study suggested that a hema, water/ethanol based adhesive system could be applied with advantages for the bonding to dentin after Er:YAG laser etching, but further studies using different chemical formulations are needed before clinical use can be recommended.

Effects of Er:YAG laser irradiation and manipulation treatments on dentin components, part 1: Fourier transform-Raman study.

The effects of laser etching, decontamination, and storage treatments on dentin components were studied using Fourier transform (FT)-Raman spectroscopy. Thirty bovine incisors were prepared to expose the dentin surface and then divided in two main groups based upon the decontamination process and storage procedure: autoclaved (group A, n=15) or stored in thymol aqueous solution (group B, n=15). The surfaces of the dentin slices were schematically divided into four areas, with each one corresponding to a treatment subgroup. The specimens were either etched with phosphoric acid (control subgroup) or irradiated with erbium-doped yttrium-aluminum-garnet (Er:YAG) laser (subgroups: I-80 mJ, II-120 mJ, and III-180 mJ, and total energy of 12 J). Samples were analyzed by FT-Raman spectroscopy; we collected three spectra for each area (before and after treatment). The integrated areas of five Raman peaks were calculated to yield average spectra. The areas of the peaks associated with phosphate content (P<0.001), type I collagen, and organic C-H bonds (P<0.05) were reduced significantly in group A (control). Analyses of samples irradiated with reduced laser energies did not show significant changes in the dentin components. These results suggest that thymol storage treatment is advised for in vitro study; furthermore, 12 J of Er:YAG laser energy does not affect dentin components.

Susceptibility of Streptococcus mutans biofilms to photodynamic therapy: an in vitro study.

OBJECTIVES: The purpose of this study was to evaluate the antimicrobial effect of toluidine blue O (TBO), in combination with either a helium/neon (HeNe) laser or a light-emitting diode (LED), on the viability and architecture of Streptococcus mutans biofilms. METHODS: Biofilms were grown on hydroxyapatite discs in a constant depth film fermentor fed with artificial saliva that was supplemented with 2% sucrose four times a day, thus producing a typical 'Stephan pH curve'. Photodynamic therapy was subsequently carried out on biofilms of various ages with light from either the HeNe laser or LED using energy densities of between 49 and 294 J/cm(2). RESULTS: Significant decreases in the viability of S. mutans biofilms were only observed when biofilms were exposed to both TBO and light, when reductions in viability of up to 99.99% were observed with both light sources. Overall, the results showed that the bactericidal effect was light dose-dependent and that older biofilms were less susceptible to photodynamic therapy. Confocal laser scanning microscopy images suggested that lethal photosensitization occurred predominantly in the outermost layers of the biofilms. CONCLUSIONS: Photodynamic therapy may be a useful approach in the treatment of dental plaque-related diseases.

Effect of Er:YAG laser on adhesion of root canal sealers.

This in vitro study evaluated the effect of Er:YAG laser on adhesion to human dentin of Grossman, Endomethasone, N-Rickert, and Sealer 26 root canal sealers. The crowns of 40 human molars were cut on the occlusal side until a flat dentin surface was obtained. The teeth were divided into two groups: group 1, no laser application; and group 2, irradiation with Er:YAG laser (KaVo Key Laser 2; 11 mm focal distance, perpendicular to the dentin surface, 4 Hz frequency, 200 mJ energy, 62 J total energy and 313 pulses, 1-min application time, and 2.25 W power). Five samples were tested for each sealer and each group. An Instron universal testing machine was used for the adhesion test. Sealer 26 showed the best adhesion both with and without laser application (p < 0.01). Grossman and N-Rickert sealers had intermediate values, and Endomethasone had the worst adhesion. Application of Er:YAG laser did not alter the adhesion of Grossman, N-Rickert, or Endomethasone sealers. However, laser application increased the adhesion of Sealer 26. The epoxy resin-based root canal sealer (Sealer 26) adhered better to dentin prepared with and without Er:YAG laser than the zinc oxide/eugenol-based sealers (Endomethasone, N-Rickert, and Grossman).