Abstract Objective This study verified the occurrence of dental sensitivity in patients submitted to a 35% hydrogen peroxide based product (Whiteness HP Maxx 35% – FGM), skin cold sensation threshold (SCST) and its influence on dental sensitivity. Material and Methods Sixty volunteers were divided into 4 groups (n = 15), according to SCST (low: GI and GIII, and high: GII and IV) and bleaching treatment (hydrogen peroxide: GI and GII, and placebo: GIII and GIV). SCST was determined in the inner forearm for 6 different times using a neurosensory analyzer, the TSA II (Medoc Advanced Medical Systems, Ramat Yishai, Northern District, Israel). Dental sensitivity measurements were performed 10 different times using a thermal stimulus and an intraoral device attached to TSA II, positioned in the buccal surface of the upper right central incisor. Spontaneous dental sensitivity was also determined using the Visual Analogue Scale (VAS). Data were submitted to Student's t-test and Pearson's Correlation Test (α=0.05). SCST remained the same during bleaching treatment. Results Distinct responses of dental sensitivity were found in patients with low and high SCST during the first and third bleaching session (p≤0.05). The teeth submitted to the bleaching treatment became more sensitive to cold than those treated with placebo. Moreover, data obtained with TSA and VAS presented moderate correlation. Conclusions Bleaching treatment increased dental sensitivity and skin cold sensation threshold might represent a determining factor in this occurrence, since low and high SCST patients had different responses to the thermal stimulus in the teeth.

Abstract Objective The objective of this study was to evaluate dental sensitivity using visual analogue scale, a Computerized Visual Analogue Scale (CoVAS) and a neurosensory analyzer (TSA II) during at-home bleaching with 10% carbamide peroxide, with and without potassium oxalate. Materials and Methods Power Bleaching 10% containing potassium oxalate was used on one maxillary hemi-arch of the 25 volunteers, and Opalescence 10% was used on the opposite hemi-arch. Bleaching agents were used daily for 3 weeks. Analysis was performed before treatment, 24 hours later, 7, 14, and 21 days after the start of the treatment, and 7 days after its conclusion. The spontaneous tooth sensitivity was evaluated using the visual analogue scale and the sensitivity caused by a continuous 0°C stimulus was analyzed using CoVAS. The cold sensation threshold was also analyzed using the TSA II. The temperatures obtained were statistically analyzed using ANOVA and Tukey's test (α=5%). Results The data obtained with the other methods were also analyzed. 24 hours, 7 and 14 days before the beginning of the treatment, over 20% of the teeth presented spontaneous sensitivity, the normal condition was restored after the end of the treatment. Regarding the cold sensation temperatures, both products sensitized the teeth (p<0.05) and no differences were detected between the products in each period (p>0.05). In addition, when they were compared using CoVAS, Power Bleaching caused the highest levels of sensitivity in all study periods, with the exception of the 14th day of treatment. Conclusion We concluded that the bleaching treatment sensitized the teeth and the product with potassium oxalate was not able to modulate tooth sensitivity.

Resumo Este estudo teve como objetivo avaliar a penetração trans-amelodentinária do peróxido de hidrogênio (H2O2) aplicados em dentes bovinos pigmentados com chá preto em diferentes intensidades. Divisão dos grupos: AD em água destilada; CP100 em uma infusão de 1,6 g de chá preto para 100 mL de água destilada; CP10 em uma infusão de 1,6 g de chá preto para 10 mL de água destilada. Todos os grupos foram imersos por 6 dias. Para quantificar a penetração de H2O2, as amostras foram colocadas em câmaras pulpares artificiais (CPAs) e submetidas a um tratamento clareador com PH a 38%, uma vez por semana durante 3 semanas. Após o tratamento clareador, a solução tampão de acetato das CPAs com a enzima da peroxidase, foi avaliada num espectrofotômetro de reflexão. A penetração trans-amelodentinária de PH e os valores de L* obtidos em T1, T2 e T3 foram submetidos ao teste estatístico de Kruskal-Wallis e Friedman. Em T1, a difusão de H2O2 no AD foi mais elevada do que em CP100 e CP10. Nos outros tempos de avaliação, os valores de penetração no CP100 e CP10 aumentaram e permaneceram semelhantes. Os valores L* aumentaram significativamente em todos os grupos no T1. No T2, os valores L* foram maiores no AD e os valores em CP100 e CP10 foram semelhantes entre si. No último tempo, o CP10 apresentou os menores valores de L*. Diferentes níveis de pigmentação não afetaram a penetração de H2O2 através do esmalte e dentina e o agente de clareador foi eficaz na alteração cromática.

Abastract This study aimed to evaluate the transenamel and transdentinal penetration of hydrogen peroxide (H202) applied to bovine teeth pigmented with black tea at different intensities. The following groups were formed DW: immersion in distilled water; BT100: immersion in an infusion of 1.6 g of black tea per 100 mL distilled water; BT10: immersion in an infusion of 1.6 g black tea per 10 mL distilled water. All groups were immersed for 6 days. To quantify the penetration of H202, the specimens were placed in artificial pulp chambers (APCs) and subjected to bleaching treatment with 38% H2O2 once per week for 3 weeks. After bleaching treatment, the acetate buffer solution of APCs with peroxidase enzyme was evaluated in a reflection spectrophotometer. The transenamel and transdentinal penetration of H2O2 and the L* values obtained at T1, T2 and T3 were subjected to Kruskal-Wallis and Friedman statistical tests. At T1, the H2O2 diffusion in DW was higher than that in BT100 and BT10. At the other evaluation times, the penetration values in BT100 and BT10 increased and remained similar. The L* values increased significantly in all groups at T1. At T2, the L* values were higher in DW, while the values in BT100 and BT10 were similar to each other. At the end of the experiment, BT10 showed the lowest L* values. The pigmentation level did not affect the penetration of H2O2 through the enamel and dentin and the bleaching agent effectively changed the color of the teeth.

ABSTRACT Dental materials in general are tested in different animal models prior to the clinical use in humans, except for bleaching agents. Objectives To evaluate an experimental rat model for comparative studies of bleaching agents, by investigating the influence of different concentrations and application times of H2O2 gel in the pulp tissue during in-office bleaching of rats’ vital teeth. Material and Methods The right and left maxillary molars of 50 Wistar rats were bleached with 20% and 35% H2O2 gels, respectively, for 5, 10, 15, 30, or 45 min (n=10 rats/group). Ten animals were untreated (control). The rats were killed after 2 or 30 days, and the maxillae were examined by light microscopy. Inflammation was evaluated through histomorphometric analysis with inflammatory cell count in the coronal and radicular thirds of the pulp. Fibroblasts were also counted. Scores were attributed to odontoblastic layer and vascular changes. Tertiary dentin area and pulp chamber central area were measured histomorphometrically. Data were compared by analysis of variance and Kruskal-Wallis test (p<0.05). Results After 2 days, the amount of inflammatory cells increased in the coronal pulp occlusal third up to the 15-min application groups of each bleaching gel. In the groups exposed to each concentration for 30 and 45 min, the number of inflammatory cells decreased along with the appearance of necrotic areas. After 30 days, reduction on the pulp chamber central area and enlargement of the tertiary dentin area were observed, without the detection of inflammation areas. Conclusion The rat model of extracoronal bleaching showed to be adequate for studies of bleaching protocols, as it was possible to observe alterations in the pulp tissues and tooth structure caused by different concentrations and application periods of bleaching agents.

Resumo O peróxido de hidrogênio (H2O2) é capaz de penetrar pelos tecidos dentários, alterando a coloração destes, e causar danos a polpa. Este estudo avaliou a penetração por esmalte e dentina, a alteração de cor e a reposta tecidual pulpar, provocadas pelo uso de duas concentrações de H2O2 em protocolos de clareação dentária de consultório. Discos de dentes bovinos em câmaras pulpares artificiais receberam géis clareadores para avaliação da penetração por esmalte e dentina e da alteração de cor, formando os grupos: BLU (H2O2 20% - 1x50 min, Whiteness HP Blue); MAX (H2O2 35% - 3x15 min, Whiteness HP Maxx); e Controle (gel placebo - 1x50 min). A penetração por esmalte e dentina foi quantificada baseada na reação do H2O2 com o corante violeta leucocristal, e a alteração de cor foi analisada pelo sistema CIELab. Vinte ratos Wistar foram divididos em dois grupos (BLU e MAX), e tiveram os molares direito superiores tratados com os mesmos protocolos do estudo in vitro; os molares superiores do lado esquerdo serviram de controle. Após 2 dias, os animais foram eutanasiados e as maxilas examinadas por microscopia de luz. Foram atribuídos escores ao infiltrado inflamatório (1, ausente; 2, leve; 3, moderado; 4 severo ou necrose). Os dados foram submetidos a testes estatísticos (=0,05). O grupo MAX apresentou maior penetração de H2O2 por esmalte e dentina (p<0,05). A alteração de cor foi semelhante nos grupos clareados (p>0,05), mas diferente quando comparados grupos clareados com controle (p<0,05). MAX apresentou inflamação severa nos terços superiores da polpa coronária, e BLU apresentou inflamação moderada (p<0,05). Assim, protocolo para procedimento clareador de consultório utilizando baixas concentrações de H2O2 deve ser de escolha na clínica, por reduzir a penetração por esmalte e dentina, causando menos danos à polpa, e proporcionar mesma eficiência clareadora.

Abstract Hydrogen peroxide (H2O2) penetrates into the dental hard tissues causing color alteration but also alterations in pulpal tissues. Hard-tissue penetration, color alteration and the pulp response alterations were evaluated for two in-office bleaching protocols with H2O2. For trans-enamel/dentin penetration and color alteration, discs of bovine teeth were attached to an artificial pulp chamber and bleached according to the groups: BLU (20% H2O2 - 1x50 min, Whiteness HP Blue); MAX (35% H2O2 - 3x15 min, Whiteness HP Maxx); Control (1x50 min, placebo). Trans-enamel/dentin penetration was quantified based on the reaction of H2O2 with leucocrystal violet and the color analyzed by CIELab System. Twenty Wistar rats were divided into two groups (BLU and MAX) and their maxillary right molars were treated according to the same protocols of the in vitro study; the maxillary left molars were used as controls. After 2 days, the animals were killed and their maxillae were examined by light microscopy. The inflammation of pulp tissue was scored according to the inflammatory infiltrate (1, absent; 2, mild; 3, moderate; 4, severe/necrosis). Data were analyzed by statistical tests (α=0.05). MAX showed higher trans-enamel/dentinal penetration of H2O2 (p<0.05). The color alteration was similar for both groups (p>0.05), and different when compared to Control group (p<0.05). MAX showed severe inflammation in the upper thirds of the coronal pulp, and BLU showed moderate inflammation (p<0.05). In-office bleaching protocols using lower concentrations of hydrogen peroxide should be preferred due to their reduced trans-enamel/dentinal penetration since they cause less pulp damage and provide same bleaching efficiency.

ABSTRACT Dental materials, in general, are tested in different animal models prior to their clinical use in humans, except for bleaching agents. Objectives To evaluate an experimental rat model for comparative studies of bleaching agents by investigating the influence of different concentrations and application times of H2O2 gel in the pulp tissue during in-office bleaching of rats’ vital teeth. Material and methods The right and left maxillary molars of 50 Wistar rats were bleached with 20% and 35% H2O2 gels, respectively, for 5, 10, 15, 30, or 45 min (n=10 rats/group). Ten animals (control) were untreated. The rats were killed after 2 or 30 days, and the maxillae were examined by light microscopy. Inflammation was evaluated by histomorphometric analysis with inflammatory cell counting in the coronal and radicular thirds of the pulp. The counting of fibroblasts was also performed. Scores were attributed to the odontoblastic layer and to vascular changes. The tertiary dentin area and the pulp chamber central area were histomorphometrically measured. Data were compared by the analysis of variance and the Kruskal-Wallis test (p<0.05). Results After 2 days, the amount of inflammatory cells increased in the occlusal third of the coronal pulp until the time of 15 min for both concentrations of bleaching gels. In 30 and 45 min groups of each concentration, the number of inflammatory cells decreased along with the appearance of necrotic areas. After 30 days, a reduction in the pulp chamber central area and an enlargement of tertiary dentin area were observed without the detection of inflammation areas. Conclusion The rat model of extra coronal bleaching showed to be adequate for bleaching protocols studies, as it was possible to observe alterations in the pulp tissues and in the tooth structure caused by different concentrations and periods of application of bleaching agents.

O objetivo do presente estudo foi quantificar a sensibilidade dentaria durante o tratamento clareador e apos a aplicacao de um dessensibilizante utilizando um equipamento de analise neurosensorial, o TSA II, que utiliza estimulos termicos para a realizacao do Teste Sensorial Quantitativo (QST). Assim, dez pacientes (n=10) receberam o tratamento clareador com Whiteness HP Maxx (FGM Produtos Odontologicos Ltda.) contendo peroxido de hidrogenio a 35%. Apos a sessao clareadora, os dentes foram limpos com jatos de ar/agua e foi realizada a aplicacao do Desensibilize KF 2% (FGM Produtos Odontologicos Ltda.), um dessensibilizante topico a base de nitrato de potassio a 5% e fluoreto de sodio a 2%, apenas no hemi-arco esquerdo da maxila, utilizando o metodo da boca dividida. No hemi-arco direito foi aplicada uma solucao salina a temperatura ambiente (controle). O QST foi realizado antes do clareamento (AC), imediatamente depois do clareamento (DC) e imediatamente apos a aplicacao do dessensibilizante (DD). Para padronizar o local do estimulo, uma moldeira de acetato com perfuracoes circulares foi utilizada durante as mensuracoes. A analise estatistica foi realizada por meio do teste t de Student (α=0,05). As temperaturas medias (DP) do limiar de sensacao ao frio para o hemi-arco direito foram: AC- 13,898 (4,81), DC-19,241 (3,68), DD-20,646 (3,72) e para o hemi-arco esquerdo foram: AC-14,102 (3,22), DC-19,646 (4,82), DD-13,835 (3,63). Clareamento dental com peroxidos de alta concentracao exacerbaram a sensibilidade dental ao estimulo termico e o uso do dessensibilizante foi efetivo para reverter esta situacao.

The aim of this study was to quantify tooth sensitivity during bleaching and after a desensitizing treatment. Sensitivity was measured with a new device, TSA-II, which uses thermal stimuli for Quantitative Sensory Testing (QST). Ten patients underwent bleaching treatment using Whiteness HP Maxx (FGM Produtos Odontologicos Ltda) containing 35% hydrogen peroxide. After the bleaching session, the teeth were cleaned with air/water spray and the product Desensibilize KF 2% (FGM Produtos Odontologicos Ltda) was applied to the upper left teeth. Saline solution at room temperature was applied in the upper right teeth. QST was performed before bleaching, immediately after bleaching, and immediately after desensitizing treatment. In order to standardize tooth analysis, a 100% ethylene copolymer and vinyl acetate tray with circular perforations was used during measurements. Analysis of variance and the Student’s t-test were used (a=0.05). Mean temperatures (SD) of cold sensation threshold for the upper right quadrant were: BB-13.898 (4.81), AB- 19.241 (3.68), AD-20.646 (3.72) and for the upper left quadrant they were: BB-14.102 (3.22), AB-19.646 (4.82), AD- 13.835 (3.63). Dental bleaching with highly concentrated peroxides changed dental cold sensation thresholds, but the topical desensitizer changed the immediate cold sensation thresholds produced by the cold stimulus.

A proposta deste estudo foi avaliar a correlacao entre a espessura da camada hibrida e comprimento dos tags com a resistencia adesiva de um sistema adesivo auto-condicionante, quando aplicado em dentina higida. Depois da realizacao dos procedimentos restauradores, dez especimes foram seccionados ao meio na direcao mesio-distal. Uma metade foi utilizada para analise em microscopia optica, onde os comprimentos dos tags e espessura da camada hibrida foram mensuradas, a outra metade foi analisada por meio do teste de microtracao (0,5 mm/min). As superficies de fratura foram classificadas com o uso de lupa estereoscopica (aumento de 40×). Os resultados foram submetidos a analise estatistica por meio do Teste de Correlacao de Pearson (a = 0,05). Os valores da espessura da camada hibrida, comprimento dos tags resinosos e resistencia adesiva foram obtidas, sendo 2,19 µm (0,34), 4,34 µm (0,28) e 9,73 MPa (5,55), respectivamente. Alem disso, o teste de correlacao entre os comprimentos dos tags resinosos e a resistencia adesiva (r=0,014) e a espessura da camada hibrida e a resistencia adesiva (r=0,43), nao mostraram correlacao estatistica. O teste de microtracao do adesivo auto-condicionante Adper Prompt L Pop nao apresentou correlacao com a espessura da camada hibrida e o comprimento dos tags resinosos.

The purpose of this study was to evaluate the correlation between the hybrid layer thickness, resin tag length and resin bond strength of a self-etching adhesive system to sound dentin tissue "in vivo". After performing restorative procedures and tooth extractions, ten specimens were sectioned in a mesiodistal direction. One dental section was used for light microscope analysis, in which both the resin tag length and hybrid layer thickness were measured, while the other section was analyzed using a microtensile test (0.5 mm/min). The fractured surface of the latter section was characterized using a stereoscopic magnifying glass (40× magnification). The results were subject to statistical analysis using the Pearson Correlation Test (a = 0.05). The hybrid layer thickness, resin tag length and resin bond strength mean values were 2.19 µm (0.34), 4.34 µm (0.28) and 9.73 MPa (5,55), respectively. In addition, correlation tests between the resin tag length and the resin bond strength (r=0.014) and also between the hybrid layer thickness and bond strength (r=0.43), showed no statistically significant correlation. The microtensile bond strength of Adper Prompt L Pop self-etching adhesive system does not depend on hybrid layer thickness or resin tag length.

Objetivos: O objetivo deste estudo foi avaliar utilizando um sistema adesivo de 2 passos de condicionamento ácido total, a correlação entre a espessura da camada híbrida (CH) e a resistência de união (RU), e entre o comprimento dos tags resinosos (TR) e a RU em um mesmo dente utilizando, assim como o padrão de fratura dos espécimes testados. Material e método: Dez molares humanos foram utilizados para o procedimento restaurador e seccionados em duas metades (mésio-distal). Os materiais utilizados foram Adper ™ Single Bond 2, 3M ESPE, gel Ultra ™ etch, Ultradent e Filtek Z250, 3M ESPE.Uma metade foi utilizada para a microscopia de luz (400x) para se obter a espessura da CH e o comprimento dos TR, e a outra metade foi submetida ao teste de microtração para obtenção da RU. As superfícies fraturadas foram analisadas por microscopia eletrônica de varredura e os padrões de fratura classificados. O teste de correlação de Pearson foi aplicado p=0.05. Resultados: Os resultados das análises de cada espécime (CH, TR e RU), em seguida, foram correlacionados: CH espessura média = 4,39(0,48) μm, comprimento médio dos TR = 9,94(1,69) μm, média da RU= 23,98(10,24) MPa. Correlação estatisticamente significativa foi encontrada entre a espessura da CH e RU (r=0,93). Conclusão: o sistema adesivo de condicionamento ácido total de dois passos mostrou forte correlação entre a espessura da camada híbrida e resistência de união. Os tipos de fraturas mais comuns foram a adesiva, seguida da coesiva na resina.

The objective of this study was to evaluate the use of a two-step total etch and rinse adhesive, the correlation between the hybrid layer thickness (HL) and bond strength (BS), and between resin tag length (RT) and bond strength in the same teeth, and also to evaluate the fracture patterns of the tested specimens. Ten human molars were used for the restorative procedure and then sectioned in two halves (mesio-distally). The materials used were Adper™ Single Bond 2, 3M ESPE, Ultra etch gel, Ultradent and Filtek™ Z250, 3M ESPE. One half were utilized to measure the HL thickness and RT length through light microscopy analysis (400x), and the other half was subject to a microtensile test to measure the BS. The fractured surfaces were analyzed by scanning electron microscopy and fracture patterns classified. The Pearson correlation test was applied (p=0.05). The results of the analyses of each specimen then were correlated: mean HL thickness = 4.39(0.48) μm, mean length of RT = 9.94(1.69) μm, mean BS = 23.98(10.24) MPa. A statistically significant correlation between HL thickness and bond strength was found (r=0.93). The two step etch and rinse adhesive system, showed a strong correlation between HL thickness and bond strength. The most common fractures were adhesive, followed by cohesive in resin.

O objetivo deste estudo foi avaliar os efeitos de cinco produtos clareadores a base de peroxido de carbamida 15-16% na microdureza da resina composta microhibrida Z-250 (3M/Espe). Setenta e dois especimes foram confeccionados com o uso de matrizes cilindricas (4×2 mm), preenchidas com resina composta e fotoativadas por 40 segundos. Eles foram divididos em 6 grupos de estudo (n=12), de acordo com o produto clareador utilizado: Review (SS White), Magic Bleaching (Vigodent), Opalescence (Ultra dent), Whiteness Perfect (FGM), Claridex (Biodinamica), e um grupo controle (nao clareado). Os especimes receberam 1 cc de produto clareador por 6 horas diarias durante 2 semanas, e durante todo o tempo eles foram mantidos em saliva artificial. Depois dos procedimentos clareadores todos os especimes foram analisados em um microdurometro. As medidas de dureza Knoop foram submetidas a analise estatistica parametrica (analise de variancia e Teste de Tukey). Os valores de dureza Knoop e seu desvio padrao foram: baseline, 68,52a (4,28); controle, 63,42b (7,16); Whiteness Perfect, 57,57c (1,81); Magic Bleaching, 57,22c (3,84); Opalescen ce, 57,03cd (4,00); Claridex, 53,64de (3,33); Review, 51,45e (2,82). Letras semelhantes significam resultados estatisticos semelhantes segundo o teste de Tukey, nivel de significancia 5%. Os produtos clareadores diminuiram significativamente a microdureza da resina composta microhibrida Z-250 (3M/Espe).

The purpose of this study was to evaluate the effects of five home bleaching products containing 15-16% carbamide peroxide on the microhardness of microhybrid composite resin Z-250 (3M/Espe). A total of 72 specimens were fabricated in cylindrical acrylic matrices (4×2 mm), filled with composite resin and photo-activated for 40 seconds. They were divided in 6 study groups (n=12), according to the bleaching product: Review (SS White), Magic Bleaching (Vigodent), Opalescence (Ultra dent), Whiteness Perfect (FGM), Claridex (Biodinamica), and a control group (not bleached). Specimens were exposed to 1 cc of bleaching gel for 6 hours daily for 2 weeks. The control group specimens were kept in artificial saliva throughout this time. All the specimens were then analyzed in a microhardness tester. Knoop hardness measurements were performed, and the results were submitted to parametric statistical analysis (analysis of variance and Tukey´s test). Mean Knoop values and standard deviation were: baseline, 68.52a (4.28); control, 63.42b (7.16); Whiteness Perfect, 57.57c (1.81); Magic Bleaching, 57.22c (3.84); Opalescen ce, 57.03cd (4.00); Claridex, 53.64de (3.33); Review, 51.45e (2.82). Identical letters mean statistical equality according to Tukey’s test at the 5% significance level. The products significantly decreased Z-250 (3M/Espe) microhardness.

O objetivo dessa pesquisa foi mensurar a espessura da camada hibrida de adesao (CH), o comprimento dos prolongamentos resinosos (Tags) e a resistencia de uniao (RU) em um mesmo especime e analisar a correlacao entre esses fatores, usando o adesivo autocondicionante Adper Prompt L Pop em dentina higida. Dez molares humanos foram utilizados e apos a realizacao dos procedimentos restauradores, de acordo com os fabricantes, cada especime foi cortado ao meio no sentido mesio/distal. Em uma hemi-seccao dental os especimes foram descalcificados para analise e mensuracao dos tags e da camada hibrida de adesao em microscopia optica comum (AXIOPHOT, 400X). Na outra hemi-seccao, foi realizado o teste de microtracao em uma velocidade de 0,5 mm/min ate sua ruptura. A superficie fraturada foi mensurada e classificada de acordo com o tipo de fratura observada em microscopia eletronica de varredura. Os valores obtidos para os fatores em analise, correspondentes a cada especime foram submetidos a um teste de correlacao. As medias correspondentes a CH, Tags e RU foram 3,36μm, 12,97 μm 14,10 MPa, respectivamente. Nao foi observado correlacao entre a CH e RU (R2= 0,011, p>0,05) e entre os Tags e RU (R2= 0,038). Diante dos resultados, observamos nao haver correlacao entre a camada hibrida e a resistencia a tracao, assim como entre os tags e a resistencia a tracao do sistema adesivo autocondicionante empregado.

The objective of this study was to measure the thickness of the hybrid layer (HLT), length of resin tags (RTL) and bond strength (BS) in the same teeth, using a self-etching adhesive system Adper Prompt L Pop to intact dentin and to analyze the correlation between HLT and RTL and their BS. Ten human molars were used for the restorative procedures and each restored tooth was sectioned in mesio-distal direction. One section was submitted to light microscopy analysis of HLT and RTL (400×). Another section was prepared and submitted to the microtensile bond test (0.5 mm/min). The fractured surfaces were analyzed using scanning electron microscopy to determine the failure pattern. Correlation between HLT and RTL with the BS data was analyzed by linear regression. The mean values of HLT, RTL and BS were 3.36 μm, 12.97 μm and 14.10 MPa, respectively. No significant relationship between BS and HLT (R2= 0.011, p>0.05) and between BS and RTL (R2= 0.038) was observed. The results suggested that there was no significant correlation between the HLT and RTL with the BS of the self-etching adhesive to dentin.

O capeamento pulpar é um procedimento que consiste na adequada proteção do tecido pulpar exposto ao meio oral, objetivando a preservação de sua vitalidade e suas funções. O objetivo deste trabalho foi observar a resposta da polpa dental de cães ao capeamento com o agregado de trióxido mineral (MTA) ou hidróxido de cálcio P.A. Para tanto, 37 dentes foram divididos em dois grupos, de acordo com o material capeador utilizado. Dois cães foram anestesiados e após o isolamento absoluto do campo operatório, realizou-se exposição padronizada da polpa, proteção com os materiais capeadores testados e selamento das cavidades com cimento modificado de ionômero de vidro. Os dentes foram então restaurados com resina composta. Após sessenta dias, os animais foram sacrificados e as peças foram processadas para a análise microscópica dos dentes. Observou-se que o MTA apresentou maior índice de sucesso em relação ao hidróxido de cálcio, evidenciando menor ocorrência de infecção e necrose pulpar.

Pulp capping is a procedure that comprises adequate protection of the pulp tissue exposed to the oral environment, aiming at the preservation of its vitality and functions. This study evaluated the response of the dental pulps of dog teeth to capping with mineral trioxide aggregate (MTA) or calcium hydroxide P.A. For that purpose, 37 teeth were divided into two groups, according to the capping material employed. Two dogs were anesthetized and, after placement of a rubber dam, their pulps were exposed in a standardized manner and protected with the experimental capping materials. The cavities were then sealed with resin-modified glass ionomer cement and restored with composite resin. After sixty days, the animals were killed and the specimens were processed in order to be analyzed with optic microscopy. It was observed that MTA presented a higher success rate compared to calcium hydroxide, presenting a lower occurrence of infection and pulp necrosis.