Assessment of the effect of experimental gel of pregabalin associated with 35% hydrogen peroxide bleaching on bovine dental enamel: an in vitro study.

To assess the effect of bleaching with gel of pregabalin associated with 35% hydrogen peroxide on the mechanical and chemical properties and ultramorphology of dental enamel. Thirty-six (36) specimens of bovine dental incisors were obtained and divided into three groups (n = 12), namely: CG = bleaching with 35% hydrogen peroxide; KFG = bleaching with 5% potassium nitrate and 2% sodium fluoride gel + 35% hydrogen peroxide; and PGG = bleaching with experimental gel of pregabalin + 35% hydrogen peroxide. The specimens were assessed with respect to Knoop microhardness, surface roughness, and colour change, before and after bleaching. They were also assessed using scanning electron microscopy and energy-dispersive spectroscopy after treatments. All groups exhibited an increase in surface roughness and a reduction in Knoop microhardness after the protocols. There was colour change in all groups, with no difference between them. In addition, there were changes in enamel morphology and non-significant loss of calcium and phosphorus. The experimental gel of pregabalin did not influence the action of 35% hydrogen peroxide, yielding results similar to those of the other groups assessed in all the parameters. Therefore, the gel of pregabalin can be an alternative for topical application on the surfaces of the teeth in association with bleaching treatments.

Combination of two desensitizing protocols to control dentin hypersensitivity in non-carious lesions: a randomized, double-blind clinical trial.

OBJECTIVES: This study evaluated the effect of photobiomodulation (PBM) combined with 8% strontium acetate (SA8%) in the treatment of dentin hypersensitivity (DH) in non-carious lesions and analyzed the risk factors with the patient's quality of life. METHODS: Eighty teeth with DH were randomly allocated into four treatment groups (n = 20): G1, PBM imitation + toothpaste with no active ingredient; G2, PBM imitation + toothpaste with SA8%; G3, PBM + toothpaste without the active ingredient; and G4, PBM + toothpaste with SA8%. Participants were provided with a questionnaire on the experience of dentin hypersensitivity (QEDH) to assess the impact of desensitizing treatment on health-related quality of life (HRQL). Friedman and Kruskal-Wallis tests were used for intra- and intergroup comparisons, and Wilcoxon and Mann-Whitney tests were used to analyze HRQL. All analyses used significance levels of 5%. RESULTS: Intergroup comparisons revealed a significant difference (p < 0.05); G4 had the best response in terms of HD reduction in G4 compared to the other groups on the 7th day of assessment (T3). Only G4 showed a statistically significant difference (p < 0.05) in the reduction of EDH for intragroup analysis. CONCLUSION: The combination of therapies was more effective in reducing DH than the isolated use of these strategies. CLINICAL RELEVANCE: The combination of therapies is effective in the treatment of DH.

Combination of strontium chloride and photobiomodulation in the control of tooth sensitivity post-bleaching: A split-mouth randomized clinical trial.

OBJECTIVE: This split-mouth randomized controlled clinical trial assessed the effect of 10% strontium chloride in combination with photobiomodulation (PBM) for the control of tooth sensitivity (TS) post-bleaching. METHODS: The upper/lower, right and left quadrants of fifty volunteers were randomized and allocated to four groups (n = 25): PLACEBO-placebo gel + simulation of PBM; Placebo + PBM; STRONTIUM-10% strontium chloride + simulation of PBM; and PBM + STRONTIUM-10% strontium chloride + PBM. All groups received tooth bleaching treatment with 35% hydrogen peroxide. For the PBM treatment, the laser tip was positioned in the apical and cervical regions of the teeth bleached in the respective hemi-arch. The laser system was operated in continuous mode, using 1.7 J of energy. A dose of 60 J/cm2 was applied to each point for 16 seconds under 808 nm near-infrared light (100mW of power), with a point area of 0.028 cm2. TS was assessed during a 21-day follow-up, using the modified visual analogue scale. RESULTS: In the intragroup assessment, the Friedman test indicated that PBM + STRONTIUM promoted the greatest reduction in TS after the second week of treatment (p ≤ 0.05). The Wilcoxon-Mann-Whitney test indicated that the groups Placebo + PBM, STRONTIUM, and STRONTIUM + PBM did not differ statistically (p ≥ 0.05) in the first and third weeks of treatment The group PLACEBO exhibited the greatest TS in the first three days after each bleaching session. CONCLUSION: The combination of 10% strontium chloride with PBM was effective in reducing post-bleaching TS; however, the combination of 10% strontium chloride with PBM was effective in reducing post-bleaching TS; however, it did not differ from the individual use of Placebo + PBM or STRONTIUM groups assessed after 21 days of follow-up.

Effect of low-level laser therapy combined with 5000 parts per million fluoride dentifrice on postbleaching sensitivity: A clinical, randomized, and double-blind study.

OBJECTIVE: The aim of this double-blind, randomized, controlled clinical study was to assess the efficacy of low-level laser therapy (LLLT) combined with 5000 ppm fluoride dentifrice on postbleaching sensitivity in teeth exposed to 35% hydrogen peroxide for four weeks. MATERIALS AND METHODS: Twenty-five volunteers were evaluated using the split-mouth model in which the right and left maxillary/mandibular quadrants were randomized and allocated to one of two groups: GPLACEBO, in which the laser tip was positioned without the emission of light (placebo effect) + 5000 ppm sodium fluoride, or GLASER, which comprised LLLT + 5000 ppm sodium fluoride. For both groups, LLLT and placebo were used before bleaching, whereas fluoride was applied after bleaching. LLLT was applied at two points: on the central cervical and medial regions of the incisors, canines, and premolars in the corresponding hemi-arch. At each point, 60 J/cm2 was applied for 16 seconds with an irradiance of 3.75 W/cm2 using the therapeutic infrared device. To assess tooth sensitivity, a modified visual analogue scale was used after an evaporative stimulus, and a daily pain questionnaire was also applied. RESULTS: The Wilcoxon and Friedman tests demonstrated a significant difference in the incidence of sensitivity pain between GPLACEBO and GLASER (P ≤ .05), with different evaluation times. CONCLUSION: Teeth treated with laser therapy in combination with the topical use of sodium fluoride at each bleaching session demonstrated less sensitivity compared with the application of sodium fluoride only. CLINICAL SIGNIFICANCE: The use of a low-level laser therapy in combination with topical use of sodium fluoride improves symptoms of dentin sensitivity at each bleaching session.

Multidisciplinary aesthetic rehabilitation: case report

Objective: This work aims to report a clinical case that performed the aesthetic rehabilitation of a patient through the integration of different dental specialties (Orthodontics, Periodontics and Dentistry). Case Report: An 18-year-old female patient received compensatory orthodontic treatment for correction of class II malocclusion, overbite and overjet, and interproximal diastema. After orthodontictreatment, a gingivoplasty was performed to remove excess gingival tissue and increase the crown of the teeth, and a frenectomy for the anomalous labial frenulum removal. After periodontal treatment the in-office bleaching was conducted, and the diastema was closed with microhybrid composite resins. Conclusion: It was concluded that multiprofessional planning made possible the aesthetic / functional rehabilitation of the patient.

Objetivo: Este trabalho visa relatar um caso clínico que realizou a reabilitação estética de um paciente por meio da integração de diferentes especialidades odontológicas (Ortodontia, Periodontia e Dentística). Relato do Caso: Paciente do sexo feminino, com 18 anos, recebeu tratamento ortodôntico compensatório para correção de má-oclusão classe II, overbite e overjet acentuados, e diastemas interproximais. Após tratamento ortodôntico, foi realizada uma gengivoplastia para a remoção do excesso de tecido gengival e aumento da coroa dos dentes, e uma frenectomia para a remoção do freio labial anômalo. Após o tratamento periodontal, foi realizado um clareamento dentário de consultório, e o fechamento dos diastemas anterosuperiores e o recontorno da cosméticados dentes com resinas compostas microhíbridas. Conclusão: Concluiu-se que o planejamento integrado multiprofissional possibilitou o êxito da reabilitação estética/funcional do paciente.

Effect of 10% Strontium Chloride and 5% Potassium Nitrate with Fluoride on Bleached Bovine Enamel.

BACKGROUND: Dental whitening has been increasingly sought out to improve dental aesthetics, but may cause chemical and morphological changes in dental enamel surfaces. OBJECTIVE: This study evaluated in vitro the effect of 10% strontium chloride and 5% potassium nitrate with fluoride on bovine enamel, through tristimulus colorimetry, Knoop microhardness (KHN), and roughness after bleaching with 35% hydrogen peroxide (HP). METHODS: The specimens were divided into three groups (n=15): GControl received bleaching treatment with 35% HP; GNitrate received bleaching with 35% HP followed by the application of 5% potassium nitrate with 2% sodium fluoride; and GStrontium received bleaching with 35% HP followed by the application of 10% strontium chloride on the enamel. Next, five specimens of each experimental group were subjected to KHN and tristimulus colorimetry tests, and 10 specimens were subjected to surface roughness (SR) tests. The values obtained for the different groups were compared through analysis of variance (ANOVA) followed by a post-hoc Tukey-Kramer test in addition to Student's T-test for paired data. RESULTS: In the intergroup comparison, KHN final differed statistically (p<0.05). The mean SR final of the experimental groups differed statistically from the GControl group (p<0.05). In addition, the groups did not differ in color variation (p>0.05). CONCLUSION: 10% strontium chloride and 5% potassium nitrate combined with 2% fluoride downplayed morphological changes to the enamel, without interfering with the effectiveness of the bleaching process.

Comparative analysis of polymerization shrinkage of different resin composites.

This study sought to compare the shrinkage of 3 resin composites after polymerization, using different curing modes and 2 methods of analysis, with 45 samples in each group. To evaluate free linear shrinkage, specimens were prepared in Teflon molds (8 mm diameter x 2 mm thick) with 1 of 2 methacrylate-based resins or a silorane-based resin. To evaluate wall-to-wall shrinkage, cavities (1.5 mm thick x 3 mm diameter) were prepared in 45 healthy bovine incisors and then restored. In both tests, the same curing lights were used: conventional quartz-tungsten-halogen, a conventional light-emitting diode (LED), and an exponential LED. Gaps were measured microscopically, and the gap percentage was calculated. The results were analyzed by 2-way ANOVA and Tukey's test (α = 0.05). Curing modes differed significantly in the free linear shrinkage test group, while resin composites did not. In the wall-to-wall shrinkage group, there were significant differences between the resin composites.

Estudo in vitro do efeito de unidades fotoativadoras com diferentes comprimentos de onda na dureza (por meio de micro e ultramicroendentação) e módulo de elasticidade de uma resina composta nanohíbrida / Effect of light sources with different wavelengths in micro and ultramicrohardness and elastic modulus of a nanohybrid composite resin. An in vitro study

Este trabalho avaliou in vitro a dureza e módulo de elasticidade de uma resina composta nanohíbrida (Tetric N-Ceram/Ivoclair-Vivadent) com diferentes cores, fotoativada por duas unidades com diferentes comprimentos de onda em 3 espessuras (1, 2 e 3mm) comparadas à partir da superfície irradiada (0mm). Os espécimes foram divididos em grupos (n=5): microdureza Knoop-KHN, ultramicrodureza-DUH e módulo de elasticidade-ME, cor (A2 e Bleach-M(BM), fotoativador LEDazul (Elipar Freeligth2/3M(750mW/25s/430-480nm(FL) e LEDazul/violeta Bluephase/Ivoclar/Vivadent (1200mW/cm²/15s/380-515nm(B15) e 30s(B30). Os espécimes foram armazenados por 24h/37ºC. Os ensaios de KHN foram realizados no HMV-2000/Shimadzu, com carga de 25gf/40s, e de DUH e ME no DUH 211S/Shimadzu com força de 10mN e tempo de espera de 0s. Foram realizadas 5 endentações na superfície irradiada (0mm) e na base das amostras (1, 2 e 3mm). A análise estatística foi realizada por ANOVA, Tukey e correlação de Pearson (p<0,01%). O teste de Pearson mostrou haver correlação direta entre a KHN e a DUH. A fonte FL promoveu maiores valores de KHN e de DUH para as duas resinas testadas; enquanto que a fonte B15, promoveu o maior valor de ME. Quanto às espessuras, 0 e 1mm apresentaram maiores valores de KHN e de DUH, e menores de ME que as espessuras de 2 e 3mm. A cor A2 apresentou maior valor de KHN e DUH e menor ME que a cor Bleach-M. Assim, de acordo com a metodologia proposta e os resultados apresentados pode-se concluir que apesar de a luz LEDazul/violeta propor uma maior eficácia na polimerização de resinas de cor clara, no tocante às propriedades avaliadas isso não foi verificado.

This study evaluated in vitro the hardness (micro and ultramicro) and elastic modulus of a nanohybrid composite resin (Tetric N-Ceram/Ivoclar-Vivadent) with different colors, light sources and thickness. The specimens were divided into groups (n=5): KHN-Knoop microhardness, DUH-nanohardness and ME-elastic modulus; colors: A2 and Bleach-M (BM); light sources: LEDblue Elipar Free light 2/3M-ESPE (750mW/cm²/ 25s/430-480nm- (FL)), LEDblue/violet Bluephase/Ivoclar-Vivadent (1.200mw/cm²/15s/380-515nm) (B15) and 30s (B30); thickness: 1mm, 2mm and 3mm, compared to the irradiated surface (0mm). Specimens were stored dry for 24hours at 37ºC after photo curing. Assays were performed at KHN in HMV-2000/ Shimadzu with load of 25gf at 40s and DUH/ME in DUH 211S/Shimadzu with force of 10mN and no hold time (0s). 5 indentations of each test were made in the surfaces opposites to the photo curing. A statistical analysis was performed by ANOVA, Tukey and Pearson correlation (p<0.01%). Pearsons Test showed a direct correlation between KHN and DUH. Comparison between KHN and ME in the studied resins indicated that the light source FL promoted higher values of KHN and DUH to both resins tested, whereas the B15 light source promoted the higher ME value. Regarding thickness 0mm and 1mm showed higher KHN and DUH and lower ME than 2 and 3mm thickness. A2 color showed higher KHN and DUH and lower ME than BM. Thus, according to the proposed methods and the presented results, the LEDblue/violet was not better for curing the light color of the nanohybrid resin, than LEDblue.

The effect of fluoride therapies on the morphology of bleached human dental enamel.

The aim of this in vitro study was to evaluate qualitatively the surface morphology of enamel bleached with 35% hydrogen peroxide (HP) followed by application of fluoridated agents. Forty intact pre molars were randomly distributed into four groups (n = 10), treated as follows: Group I (control group) remained stored in artificial saliva at 37 °C, Group II - 35% HP; Group III - 35% HP + acidulated fluoride (1.23%) and Group IV - 35% HP + neutral fluoride (2%). The experimental groups received three applications of bleaching gel and after the last application all specimens were polished. This procedure was repeated after 7 and 14 days, and during the intervals of applications, the specimens were stored in artificial saliva at 37°C. Scanning electron microscopy (SEM) analysis showed superficial irregularities and porosities to varying degrees in bleached enamel compared to control group. Sample evaluation was made by attributing scores, and data were statistically analyzed using Kruskal-Wallis and Dunn tests (P < 0.05). SEM qualitative investigation demonstrated that 35% hydrogen peroxide affected human dental enamel morphology, producing porosities, depressions, and superficial irregularities at various degrees. These morphological changes were higher after the application of 1.23% acidulated fluoride gel.

Aparelhos fotopolimerizadores que empregam LEDs (Light Emitting Diodes) e lâmpada halógena de quartzo tungstênio / Photocuring units that utilize LEDs (Light Emitting Diodes) and QTH (Quartz-Tungsten Halogen) bulbs

Este estudo tem como objetivo principal descrever e comparar aparelhos fotopolimerizadores formados por LEDs (light emitting diodes) com aparelhos convencionais de lâmpada halógena. Notou-se que os aparelhos que empregam lâmpadas halógenas têm maior potência de saída, quando comparados com os que utilizam LEDs. No entanto, produzem radiação infravermelha, gerando aumento exessivo de temperatura. Os aparelhos com LEDs não provocam aquecimento demasiado, pois o espectro gerado pode ser controlado sem a presença de filtros. Alguns dados laboratoriais obtidos avaliando propriedades físicas de resinas fotoativadas por LEDs, também demonstram valores suficientes para as exigências clínicas, porém com necessidade de aumentar o tempo de irradiação. A manutenção dos aparelhos formados por LEDs apresentam custo mais baixos, sendo ainda que esses aparelhos podem ser operados por baterias, dispensando a presença de fios e uso de corrente elétrica. Não existem, todavia, dados clínicos que descrevam o comportamento de restaurações fotoativadas por meio de LEDs. Percebe-se também um grande interesse por parte dos pesquisadores e fabricantes, no sentido de aprimorar tais aparelhos, tornando-os mais atrativos e eficientes

Faceta laminada indireta em resina composta de laboratório - relato de caso clínico / Indirect laminate veneers with laboratory composite resin system - a clinical case report

Este trabalho tem o objetivo de realatar um caso clínico de reabilitação estética de um paciente utilizando resina composta de laboratório (Artglass/Heraeus/Kulzer)