Influência da espessura do esmalte e da aplicação prévia de agente dessensibilizante na eficácia do clareamento dental

Orientadores: Débora Alves Nunes Leite Lima, Luis Alexandre Maffei Sartini PaulilloDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: O objetivo deste estudo foi avaliar a influência da espessura do esmalte e a aplicação prévia de dessensibilizante na eficácia do tratamento clareador. O trabalho foi dividido em 2 estudos. No primeiro estudo foi testada a influência da espessura do esmalte (0,5mm de espessura, 1,0mm de espessura planificada, 1,0mm de espessura não planificada e sem esmalte- controle) na eficácia do clareamento em profundidade, variando-se o tipo de agente clareador, peróxido de carbamida (PC) 10% e peróxido de hidrogênio (PH) 35%. No segundo estudo foi avaliada a influência da aplicação prévia de agente dessensibilizante, fluoreto de sódio 2% e nitrato de potássio 5% associado ao fluoreto de sódio 2% e, sem agente dessensibilizante (controle) na eficácia do clareamento dental com PH35%. Nos dois estudos foram usados fragmentos dentais bovinos, pigmentados por chá preto, e distribuídos por esquema inteiramente casual no primeiro estudo e aleatório por sorteio no segundo estudo (n=10) em grupos de acordo com os tratamentos acima. As amostras foram armazenadas em saliva artificial durante as 3 semanas de tratamento. As leituras de cor da dentina oposta (1,75mm de espessura) do estudo 1 e as leituras de cor do esmalte (1,0mm de espessura) e dentina oposta (1,75mm de espessura) do estudo 2 foram realizadas após o manchamento (baseline) e após cada semana de tratamento clareador, utilizando o método CIE Lab através de espectrofotômetro (Konica Minolta CM 700 d, Japan). Para o estudo 1 os valores de ?E, ?L, ?a e ?b datados foram submetidos à análise de variância ANOVA em esquema fatorial e teste de Tukey (?=0,05). Para o estudo 2, a coordenada L* datada (L=100 - lightness; L=0 - darkness) foi submetida por meio de análise de medidas repetidas PROC MIXED e teste de Tukey-Kramer e os valores de ?E datados foram submetidos à análise de variância ANOVA e teste de Tukey (?=0,05). O esmalte de 2 amostras de cada grupo do estudo 2 foi observado em microscopia eletrônica de varredura (MEV). Nos resultados destes estudos pode-se observar que o clareamento com PC10% foi mais efetivo que o PH35% em profundidade dentinária para todos os parâmetros de delta, com exceção no terceiro tempo dos deltas. A presença da camada aprismática no esmalte interferiu na eficácia do PC10% somente no primeiro tempo de clareamento em ?E1, ?L1 e ?b1, entretanto não interferiu nos tempos de clareamento testado com PH35% (estudo 1). Ainda, o uso de agente dessensibilizante realizado previamente ao clareamento dental não interferiu no mecanismo de ação do PH35% em profundidade (estudo 2)Abstract: The aim of this study was to evaluate the influence of enamel thickness and prior application of a desensitizing agent on the effectiveness of bleaching treatment. This project was divided into two studies. Firstly, we tested the influence of enamel thickness (0.5 mm thick, 1.0 mm planned thick, 1.0 mm unplanned thick and absence of enamel - control) on the effectiveness of bleaching, in-depth, according to the type of bleaching agent, as follows: 10% carbamide peroxide and 35% hydrogen peroxide. Secondly, we evaluated the influence of prior application of a desensitizing agent (potassium nitrate associated with 2% sodium fluoride, 2% neutral fluoride, or with no desensitizing agent - control) on the effectiveness of tooth bleaching by using 35% hydrogen peroxide. In both studies we used bovine teeth fragments, stained with black tea, which were allocated into groups according to the aforementioned treatments, by an entirely causal scheme for the first study and by random drawing for the second one (n=10). The specimens were stored in artificial saliva during the 3-week-treatment. Color readings of the underlying dentin (1.75 mm thick) concerning the study 1, and color readings of enamel (1.0 mm thick) and underlying dentin (1.75 mm thick) of the study 2, were performed after staining (baseline) and after each week of bleaching treatment using the CIE Lab method by means of spectrophotometer (Konica Minolta CM 700d, Japan). For the study 1, the values of ?E, ?L, ?a and ?b recorded were subjected to factorial analysis of variance (ANOVA) and Tukey's test (? = 0.05). For the study 2, the coordinate L* recorded (L = 100 - lightness, L = 0 - darkness) was submitted to analysis of repeated measures PROC MIXED and Tukey-Kramer's test, and the ? values registered underwent analysis of variance (ANOVA) and Tukey's test (? = 0.05). The enamel of 2 specimens from each group of the study 2 was observed under scanning electron microscopy. According to the findings, it could be observed that the bleaching with 10% CP was more effective than that with 35% PH as regards dentin depth for all parameters delta, except the third time deltas. The presence of the prismless layer of enamel interfered with the effectiveness of 10% CP just in the first time of bleaching in ?E1, ?L1and ?b1, however it did not affect the times of bleaching when 35% HP was tested (study 1). In addition, the use of a desensitizing agent prior to tooth bleaching did not interfere with the mechanism of action of the 35% hydrogen peroxide concerning tooth depth (study 2)MestradoDentísticaMestra em Clínica Odontológic

Influence of surface treatments on enamel susceptibility to staining by cigarette smoke

Objectives: The purpose of this study was to evaluate the influence of remineralizing agents, including artificial saliva, neutral fluoride, and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), on the susceptibility of bleached enamel to staining by cigarette smoke. Study design: Fifty bovine enamel blocks were randomly divided into five groups (n = 10): G1- bleaching; G2- bleaching and immersion in artificial saliva; G3- bleaching and application of CPP-ACP; G4- bleaching and application of neutral fluoride; and G5- untreated (Control). Teeth were bleached with 35% hydrogen peroxide and treated with the appropriate remineralizing agent. After treatment, all groups were exposed to cigarette smoke. Enamel color measurements were performed at three different times: before treatment (T1), after treatment (bleaching and remineralizing agent) (T2), and after staining (T3), by using the CIE Lab method with a spectrophotometer. The data coordinate L* was evaluated by analysis of repeated-measures PROC MIXED and Tukey-Kramer's test, and the ?E values were submitted to one-way ANOVA and Tukey¿s test (? = 0.05). Results: The G1 group did not show any statistically significant difference for L* values between times T1 and T2. The G4 and G5 groups showed lower L* values at T3 compared to T2. No significant differences between the groups were observed for ?E (after treatment and staining). However, G4 showed a clinically apparent color change. Conclusions: Treatment of bleached enamel with neutral fluoride can contribute to the increased staining of enamel due to cigarette smoke

Estudo comparativo do acabamento / polimento superficial de resinas compostas

Este estudo teve como objetivo a análise do acabamento / polimento superficial de resinas compostas para dentes posteriores submetidas a diferentes tipos de materiais para tratamentos de acabamento e polimento. Foram confeccionados 84 corpos-de-prova cilíndricos de 5mm de diâmetro e 2mm de altura com três compósitos: P90®, Z350® e Charisma®. As amostras foram polidas utilizando-se quatro sistemas de acabamento e polimento distribuídos em doze grupos (n=7): sem acabamento e polimento (controle); acabamento com ponta diamantada 1112 FF (KG SORENSEN)(P); acabamento com ponta diamantada 1112 FF, e pontas Enhance (DENTSPLY) e Pogo (DENTSPLY); acabamento com ponta diamantada 1112 FF e pontas Enhance/Pogo e pastas Poli I, II e Fotogoloss. Cada corpo-de-prova foi levado individualmente ao rugosímetro Surfcorder SE 1700 (Kosaka Lab, Tókio, Japão), para avaliação da rugosidade superficial após o acabamento e polimento superficial, e após ciclagem mecânica. Em cada superfície, foram efetuadas quatro leituras em posições diferentes. A média das mesmas foi considerada a rugosidade de cada amostra. Os resultados foram analisados pela análise de variância e teste de comparação múltipla Tukey. Diferença estatística significante foi observada apenas para o fator sistema de acabamento/polimento. Os grupos do sistema de acabamento com ponta diamantada apresentaram a mais alta média de rugosidade, diferindo-se dos demais grupos. Assim, pode-se concluir pelos resultados deste estudo, que a variação de rugosidade foi dependente do tipo de polimento testado. A ciclagem mecânica não alterou a acabamento/polimento das superfícies das resinas compostas.This study aimed to analyze the finish / polishing surface of composite resins for posterior teeth treated at different types of materials for finishing and polishing. 84 cylindrical specimens with 5 mm in diameter and 2mm in height were made to three composites: P90 ®, Z350 and Charisma ® ®. The samples were polished using four finishing and polishing systems distributed into twelve groups (n = 7): without finishing and polishing (control), finishing with a diamond bur 1112 FF (KG Sorensen), finishing with a diamond bur 1112 FF, and Tips Enhance (DENTSPLY) and Pogo (DENTSPLY), finishing with a diamond tip Enhance and 1112 FF / Pogo and folders Poli I, II and Fotogoloss. Each body-of-evidence was taken individually to rugosimeter Surfcorder SE 1700 (Kosaka Lab, Tokyo, Japan) to evaluate the surface roughness afther finishing and polishing surface, and after mechanical cycling. In each surface, four readings were made at different positions. The average of these was considered the roughness of each sample. The results were analyzed by ANOVA and Tukey multiple comparison test. Statistically significant difference was observed only for the factor system of finishing / polishing. The groups with finishing system with diamond burs showed the highest average of roughness, differing from the other groups. Thus we can conclude through the results of this study that the variation of surface roughness was dependent on the type of polishing tested. The mechanical cycling did not alter the finisinhig/polishing of the surfaces of composite resins

Influence of different thickeners at-home tooth bleaching : a randomized clinical trial study

Orientador: Debora Alves Nunes Leite LimaTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: O objetivo deste estudo clinico foi avaliar a influencia do gel clareador peroxido de carbamida 10% contendo diferentes espessantes, carbopol (CPc) ou natrosol (CPn), na efetividade do clareamento, sensibilidade dental e citotoxicidade. Setenta voluntarios do sexo masculino e feminino com idades entre 18 e 30 anos foram divididos aleatoriamente em dois grupos: CPc e CPn (n=35). Os geis CPc e CPn foram utilizados por quatro horas diarias, durante duas semanas. As leituras de cor dos dentes foram realizadas pelo sistema CIE Lab, com parametros 'delta'L, 'delta'a, 'delta'b e 'delta'E por meio de um espectrofotometro de reflectancia (Vita Easyshade, Vident, Brea, CA, USA) nos tempos antes do clareamento, apos a primeira e segunda semana do clareamento, uma semana e um mes apos o termino do clareamento, nos dentes incisivo central e no canino superiores esquerdo. A avaliacao da sensibilidade foi realizada por meio das escalas EVA (escala visual analogica) e descritiva antes do clareamento, durante e apos uma hora do termino do clareamento diario, dentro dos tempos um, tres, sete, dez e quatorze dias durante o clareamento, e ainda sete e trinta dias apos o clareamento. As analises de citotoxicidade gin vitroh foram realizadas por meio de teste MTT com celulas odontoblasticas MDPC-23, submetidos a aplicacao dos agentes clareadores por 4 horas. Em Microscopia Eletronica de Varredura (MEV), a analise qualitativa da superficie do esmalte de cada grupo foi observada por meio de replicas. Os valores de 'delta'L,'delta'a, 'delta'b e 'delta'E datados foram submetidos a analise pelo procedimento GENMOD do programa SAS. As medidas de sensibilidade dental foram analisadas pelo teste de Friedman, seguido pelo teste de Mann-Whitney (p ou ='3.3. Ambos os geis clareadores testados provocaram sensibilidade dental. Na avaliacao celular, os espessantes carbopol e natrosol apresentam toxicidade similar com as celulas odontoblasticas MDPC-23. Nas analises em MEV, as superficies de esmalte nao apresentaram alteracoes como exposicao prismatica ou destruicoes pelo uso dos agentes clareadores. O clareamento com peroxido de carbamida 10% com os espessantes carbopol ou natrosol foram efetivos e ocasionaram sensibilidade dental e citotoxicidade semelhantesAbstract: The aim of this clinical study was to evaluate the influence of bleaching gel 10% carbamide peroxide containing different carbopol (CPc) or natrosol (CPn) thickeners, on the effectiveness of bleaching, tooth sensitivity and cytotoxicity. Seventy volunteers, both male and female, between the ages of 18 to 30, were randomly divided into two groups: CPc and CPn (n = 35). The CPc and CPn gels were used four hours daily for two weeks. The color evaluation of the teeth were performed according with the CIE Lab, with 'delta'L, 'delta'a, 'delta'b and 'delta'E parameters by the means of a reflectance spectrophotometer (Vita Easyshade, Vident, Brea, CA, USA) at the times before bleaching, after the first and second week of bleaching, one week and one month after the end of bleaching, on the central incisor and canine upper left teeth. The tooth sensitivity assessment was performed using the VAS (Analogic visual scale)and descriptive scales before bleaching, during and one hour after the end of the daily bleaching within the times one, three, seven, ten and fourteen days during bleaching, and seven and thirty days after the end of bleaching. In vitro cytotoxicity performed were done by the MTT test with MDPC-23 odontoblastic cells, submitted to application of the bleaching agents for four hours. In Scanning Electron Microscopy (SEM), the qualitative analysis of the enamel surface of each group was observed through replicates. The values of 'delta'L, 'delta'a, 'delta'b and 'delta'E dated were submitted to analysis by the GENMOD procedure of the SAS program. Tooth sensitivity measurements were analyzed by the Friedman test, followed by the Mann-Whitney test (p or =".3.3. Both bleaching gels tested caused similar tooth sensitivity. In cell evaluation, carbopol and natrosol thickeners show similar toxicity to MDPC-23 odontoblastic cells. SEM analysis, the surfaces of the enamel showed no changes in prismatic exposure or destruction by the use of bleaching agents. Bleaching with 10% carbamide peroxide with carbopol or natrosol thickeners were effective and showed similar tooth sensitivity and citotoxicityDoutoradoDentísticaDoutora em Clínica Odontológic

Efficacy Of Tooth Bleaching With The Prior Application Of A Desensitizing Agent.

In the present study, we evaluated the efficacy of bleaching on enamel and opposite dentin surfaces using 35% hydrogen peroxide (HP) with the prior application of a desensitizing agent. Thirty bovine dental fragments, with thicknesses of 1 mm enamel and 1.75 mm dentin, were stained in a solution of black tea. The fragments were randomly divided into three groups (n = 10) according to the following protocols: (a) 2% neutral fluoride + bleaching; (b) desensitizing agent + bleaching; and (c) without desensitizer + bleaching. The bleaching efficacy was evaluated four times: after staining with tea (baseline) and after each of the 3 weeks of bleaching, by means of the CIE Lab method using a reflectance spectrophotometer. The data coordinate L* was evaluated by an analysis of repeated measures with PROC MIXED and Tukey-Kramer's test. The ΔE values were subjected to anova and Tukey's test (α = 0.05). The 35% HP treatment showed greater efficacy on deep dentin after removal of the enamel stains, with increasing means during all times in all treatments. The use of a desensitizing agent prior to the bleaching session did not affect the mechanism of action of 35% HP with regard to tooth depth