ABSTRACT: The objective of this study was to determine the enamel mass variation after a prolonged bleaching treatment using a calcium-containing 4% hydrogen peroxide gel Twenty sound bovine incisors were randomly assigned to two groups (n=10) stored in G1) distilled water and G2) artificial saliva. An electronic analytic scale (.000 grams measurements) was used to determine the enamel mass variation before and after the bleaching procedures at the following evaluation times: T0) before the bleaching procedures; T1) 14 days of treatment, as instructed by the manufacturer; T2) 21 days of treatment, 50 % beyond what is instructed by the manufacturer; and T3) 28 days of treatment, 100 % beyond what is instructed by the manufacturer. The highest mean was observed at T2/G2 (0.3259 g) and the lowest at T2/G1 (0.3265 g). The specimens stored in distilled water (G1) showed 6 % mass reduction when T0 (0.3277 g) was compared to T3 (0.3277 g). On the other hand, the specimens stored in artificial saliva exhibited a significant mass increase of 19 % when T0 (0.3521 g) was compared to T3 (0.3528 g). Prolonged bleaching therapy using 4 % hydrogen peroxide with calcium resulted in a massive reduction when water was used as a storage medium. When the specimens were stored in artificial saliva, an increase in mass was observed, probably due to the mineralizing properties of the artificial saliva.

RESUMEN: El objetivo de este estudio fue determinar la variación de la masa del esmalte después de un tratamiento de blanqueamiento prolongado utilizando calcio conteniendo un gel de peróxido de hidrógeno al 4 %. Veinte incisivos bovinos intactos fueron asignados aleatoriamente a dos grupos (n-10) almacenados en G1 - agua destilada y G2- saliva artificial. Se utilizó una escala analítica electrónica (.000 gramos) para determinar la variación de la masa de esmalte antes y después de los procedimientos de blanqueamiento en los siguientes tiempos de evaluación: T0) antes de los procedimientos blanqueadores; T1) 14 días de tratamiento, según las instrucciones del fabricante; T2) 21 días de tratamiento, 50 % más allá del tiempo indicado por el fabricante; y T3) 28 días de tratamiento, 100 % más allá del tiempo indicado por el fabricante. La media más alta se observó en T2/G2 (0,3259 g) y la más baja en T2/G1 (0,3265 g). Los especímenes almacenados en agua destilada (G1) mostraron una reducción de masa del 6 % cuando se comparó T0 (0,3277 g) con T3 (0,3277 g). Por otro lado, los dientes almacenados en saliva artificial mostraron un aumento significativo de masa del 19 % cuando se comparó T0 (0,3521 g) con T3 (0,3528 g). La terapia de blanqueamiemto prolongado con calcio conteniendo un gel de peróxido de hidrógeno al 4 % condujo a una reducción masiva cuando se utilizó agua como medio de almacenamiento, mientras que los dientes almacenados en saliva artificial mostraron un aumento en la masa, probablemente debido a las propiedades remineralizadoras de la saliva artificial.

Abstract The ultrastructural and mechanical properties of enamel surface were evaluated after prolonged bleaching treatments with 10% carbamide peroxide in the presence or absence of orange juice (erosive challenge) and toothbrushing (abrasive challenge). In total, 145 incisor bovine teeth were used in this study. Twenty-five samples were prepared for the ultrastructural evaluations, and 120 samples were prepared for microhardness and roughness tests. These 120 samples were divided into eight experimental groups (n = 15): G1- artificial saliva; G2- abrasion; G3- erosion; G4- dental bleaching; G5- erosion + abrasion; G6- bleaching + abrasion; G7- bleaching + erosion; and G8- bleaching + erosion + abrasion. All groups were tested at T0 (before treatment), T1 (14 days), T2 (21 days), and T3 (28 days). Two-way analysis of variance for repeated measures and the post hoc Sidak tests (p ≤ 0.05) were used. The roughness evaluation demonstrated an increase in damage for all experimental groups with an increase in the time period. For microhardness, the groups exposed to artificial saliva (AS) and abrasive challenge did not show any differences at any time points, while the other groups showed a decrease in microhardness from T0 to T3. Ultrastructural evaluation showed different surface alterations in response to the treatments. Despite prolonged bleaching periods, the procedure caused lesser enamel surface alterations than exposure to orange juice alone or in combination with brushing.

ABSTRACT: The objective evaluate was the influence of prolonged tooth bleaching with 10 % carbamide peroxide (10CP) on tooth enamel mass variation. Ten healthy bovine incisor teeth were divided (n = 5) into G1 - storage in distilled water and G2 - storage in artificial saliva. The samples were weighed in an electronic analytical balance at the following times: T0 - before application of the bleaching gel, T1 - after 14 days of bleaching (the time recommended by the manufacturer), T2 - after 21 days of bleaching (50 % increase in the time recommended by the manufacturer), and T3 - after 28 days of bleaching (100 % increase in the time recommended by the manufacturer). The data were subjected to ANOVA for related samples (p = 0.05). The highest mean was observed in G2 (0.5982 g) and the lowest mean was observed in G1 (0.3074 g) at T2 and T3, respectively. Significant differences were observed between the groups at all times. Overall, 10CP caused variation in the enamel mass after a 100 % increase in the use time recommended by the manufacturer, with a decrease in mass when distilled water was used as the storage medium and an increase when artificial saliva was used.

RESUMEN: El objetivo fue investigar la influencia del blanqueamiento dental prolongado con peróxido de carbamida al 10 % (10CP) sobre la variación de masa del esmalte dental. Las muestras se dividieron en dos grupos: G1, diez dientes sanos de los incisivos bovinos (n = 5) en agua destilada, y G2, almacenamiento en saliva artificial. Las muestras se midieron en una escala analítica electrónica de precisión en los siguientes tiempos: T0-antes de la aplicación del gel blanqueador, T1-después de 14 días de blanqueo (el tiempo recomendado por el fabricante), T2-después de 21 días de blanqueo (aumento de 50 % en el tiempo recomendado por el fabricante), y T3-después de 28 días de blanqueo (aumento de 100 % en el tiempo recomendado por el fabricante). Los datos se presentaron al ANOVA para las muestras relacionadas (P = 0,5). La media más alta se observó en G2 (0,5982 g) y la media más baja se observó en G1 (0,3074 g) en T2 y T3, respectivamente. Se observaron diferencias significativas entre los grupos en todo momento. En general, la 10 CP causó variación en la masa del esmalte después de un aumento de 100 % en el tiempo de uso recomendado por el fabricante, con una disminución en la masa cuando el agua destilada se utilizó como medio de almacenamiento y aumentó cuando se usó saliva artificial.

Resumo O objetivo deste estudo foi avaliar a influência do uso prolongado de dentifrícios dessensibilizantes (DTs) na adesão, microdureza e rugosidade da dentina. Cento e vinte dentes incisivos bovinos foram divididos aleatoriamente em quatro grupos: G1, água destilada (WATER); G2, Colgate Total 12 (CT12); G3, Colgate Sensitive Pro-alívio (CSPR); e G4, Sensodyne Repair ?αμπ; Protect (SRP). As superfícies dentinárias foram condicionadas com EDTA a 17% e foram realizados 2 anos de escovação dental simulada (20.000 ciclos) em suas superfícies. A microdureza Knoop, rugosidade de superfície e microscopia eletrônica de varredura (MEV) foram realizadas antes e após escovação dental simulada. Para o teste de adesão por microcisalhamento, foi aplicado um sistema adesivo auto condicionante de 2 passos (Clearfil SE Bond) e foram construídos cilindros de resina composta (Filtek Z350 XT) de 0,8 mm de diâmetro. O teste de microcisalhamento foi realizado com um fio ortodôntico e com velocidade de 0,5mm/min. Os dados foram analisados para: 1) resistência de união (ANOVA 1 fator), 2) comparações de microdureza intra grupo (teste t de Student) e inter grupo (ANOVA 1 fator / teste de Tukey), 3) comparações de rugosidade intra grupo (teste t de Student / teste de Wilcoxon) e inter grupo (Kruskal Wallis / teste de Student-Newman-Keuls). O uso prolongado de ambos dentifrícios (convencional e para dentes sensíveis) não interferiu na resistência de união e produziu um aumento significativo na microdureza e rugosidade da dentina, exceto para a microdureza do grupo SRP. A técnica de escovação dental simulada com água promoveu aumento na rugosidade, sem reduzir significativamente a microdureza da dentina.

Abstract The aim of this study was to evaluate the influence of an extended use of desensitizing toothpastes (DTs) on dentin bonding, microhardness and roughness. One hundred and twenty bovine incisor teeth were randomly divided into four groups: G1, distilled water (WATER); G2, Colgate Total 12 (CT12); G3, Colgate Sensitive Pro-Relief (CSPR); and G4, Sensodyne Repair ?αμπ; Protect (SRP). Dentin surfaces were etched with 17% EDTA and 2 years of simulated tooth brushing (20,000 cycles) was performed on their surfaces. Knoop microhardness, surface roughness and scanning electron microscopy (SEM) were performed before and after the simulated tooth brushing. For microshear bonding test, a 2-step self-etching adhesive system (Clearfil SE Bond) was used and 0.8 mm diameter composite resin (Filtek Z350 XT) cylinders were built. Microshear test was performed with an orthodontic wire and with a crosshead speed of 0.5 mm/min. The data were analyzed for: 1) bond strength (one-way ANOVA), 2) microhardness intra-group (Student’s test) and inter-group (one-way ANOVA/Tukey’s test) comparisons, 3) roughness intra-group (Student’s test/Wilcoxon’s test) and inter-group (Kruskal-Wallis/Student-Newman-Keuls test) comparisons. The extended use of both dentifrices (conventional and for sensitive teeth) did not affect the bond strength and produced a significant increase in microhardness and roughness of the dentin, except for the microhardness of the SRP group. The simulated tooth brushing technique with water produced an increase in roughness, without reducing significantly the dentin microhardness.

The objective of this randomized clinical trial was to evaluate the clinical performance up to 18 months of restorations placed using ethanol-wet bonding technique (EWBT) compared with the three-step etch-and-rinse (TSER) and one-step self-etching (OSSE) approaches. Ninety-three non-carious cervical lesions (31 for each group) were restored by one experienced operator in 17 patients under relatively dry conditions using gingival retraction cord, cotton rolls and saliva ejector. Each adhesive system was randomly allocated to one of randomized cervical lesions until the three groups were present in the same subject in equal amounts. The restorations were evaluated at baseline, 6, 12 and 18 months by two blinded and calibrated examiners using the modified US Public Health Service guidelines (USPHS) for the following outcomes: retention (kappa= 1.00), staining and marginal adaptation (kappa=0.81) and analyzed by Fisher's exact and Kruskal-Wallis tests, respectively. No significant differences were observed among groups after 18 months for any of the assessed criteria (p>0.05). The intra-group analysis performed by Cochran's test (for retention) and Wilcoxon test (for marginal adaptation/staining) revealed significant differences between the time intervals baseline/18 months in marginal adaptation (p= 0.0117) and retention (p= 0.0101) for OSSE and in marginal staining for TSER (0.0051) and EWBT (p= 0.0277) groups. The survival analysis for retention criteria and the overall clinical success were performed using a log-rank test and did not show significant differences among groups (p> 0.05). All three adhesives protocols presented similar clinical performance up to 18 months.

El propósito de este ensayo clínico aleatorizado fue evaluar, durante 18 meses, el éxito clínico de las restauraciones realizadas por la técnica de adhesión húmeda en etanol (TAHE) en comparación con las técnicas de grabado independiente de tres pasos (GTP) y de autograbado de un paso (AUP). Un solo operador, especializado en odontología restaurativa, realizó sobre 17 pacientes 93 restauraciones en lesiones cervicales no cariosas (31 para cada grupo). Los diferentes protocolos adhesivos se distribuyeron aleatoriamente en las lesiones cervicales hasta que los tres grupos estuviesen presentes en el mismo paciente y en cantidades iguales. Las restauraciones fueron evaluadas a los 6, 12 y 18 meses, por dos examinadores calibrados y que no participaron del procedimiento restaurador. Las directrices modificadas del Servicio de Salud Pública de Estados Unidos (SSPEU) fueron la base para las evaluaciones de las siguientes variables: retención (kappa= 1,00), adaptación y decoloración marginal (kappa= 0,81). Estas variables fueron analizadas mediante la prueba exacta de Fisher y Kruskal-Wallis, respectivamente. No se observó diferencia significativa entre los grupos después de 18 meses en las tres variables evaluadas (p >0,05). El análisis intra-grupo hecho por la prueba de Cochran (para la retención) y la prueba de Wilcoxon (para la adaptación y decoloración marginal) revelaron diferencias significativas entre los intervalos de tiempo de la línea de base / 18 meses para la retención (p= 0,0101) y adaptación marginal en el grupo AUP (p= 0,0117), y para la decoloración marginal en los grupos GTP (p= 0,0051) e TAHE (p= 0,0277). El análisis de supervivencia para la retención, así como la comparación del éxito clínico de los protocolos adhesivos, fueron realizados con la prueba de log-rank, y no hubo diferencias significativas (p >0,05) entre los grupos. No hubo diferencia en el éxito clínico de los tres protocolos adhesivos después de 18 meses.

Dentin hypersensitivity is a relatively common clinical condition, which affects a large part of the world's population. The objective of this study was to evaluate the influence of previous and prolonged treatment with desensitizing dentifrices (DD) on bond strength to dentin, promoted by a self-etching adhesive system. Seventy non-carious bovine incisors were used, and divided into five groups (n= 14), according to the desensitizing toothpaste used, such as, G1: distilled water (WATER) (control); G2: Colgate Total 12 (CT12) (control); G3: Colgate Sensitive Pro-Relief (CSPR); G4: Sensodyne Rapid Relief (SRR); G5: Sensodyne Repair & Protect (SRP). Teeth had their buccal surfaces flattened until the exposure of dentin, and fragments of 4x4x2 mm were obtained. Fragments were included in polyvinyl chloride (PVC) cylinders and exposed to 17 % EDTA for 1 min. Subsequently, specimens were submitted to 20 000 cycles of simulated dental toothbrushing. After 24 h in artificial saliva, specimens were hybridized (Clearfil SE Bond Kuraray), as well as resin composite cylinders built on dentin surfaces. Samples were stored in distilled water, at 37 C for 24 h, and the shear bond strength was determined. The highest bond strength (MPa) value was seen in CT12 group (4.39), and the lowest one in CSPR group (3.34). Data were statistically analyzed by 1-way ANOVA (ð= 0.05), and results showed that there were no significant differences (p= 0.5986) considering the DD factor. The predominant fracture pattern was cohesive on dentin. The previous and prolonged use of different DD did not affect dentin bond strength promoted by a self-etching adhesive system.

La hipersensibilidad dentinaria es una condición clínica relativamente común, que afecta a una gran parte de la población mundial. El objetivo fue evaluar la influencia del tratamiento previo y prolongado con dentífricos desensibilizantes (DD) en fuerza de adhesión a la dentina, que promueve un sistema adhesivo de autograbado. Se utilizaron 70 incisivos bovinos no cariados, y se dividieron en cinco grupos (n= 14), de acuerdo con la pasta de dientes desensibilizante utilizada: G1: agua destilada (agua) (control), G2: Colgate Total 12 (CT12) (control), G3: Colgate Sensitive Pro-Alivio (CSPR), G4: Sensodyne Rápido Alivio (SRR) y G5: Sensodyne Repair & Protect (SRP). Los dientes tenían sus superficies bucales aplanadas hasta la exposición de la dentina, y se obtuvieron fragmentos de 4x4x2 mm. Los fragmentos se incluyeron en cilindros de cloruro de polivinilo y se expusieron a 17 % de EDTA durante un 1 min. Después, las muestras se sometieron a 20 000 ciclos de cepillado dental simulado. Después de 24 h en saliva artificial, las muestras se hibridaron (Clearfil SE Bond - Kuraray), y cilindros de resina compuesta fueron construidos sobre superficies de dentina. Las muestras se almacenaron en agua destilada, a 37 °C durante 24 h y luego se determinó la resistencia al cizallamiento. El mayor valor de resistencia a la unión (MPa) se observó en el grupo CT12 (4,39), y el menor en el grupo CSPR (3,34). Los datos fueron analizados estadísticamente mediante ANOVA de un factor 1 (ð= 0,05), y los resultados no mostraron diferencias significativas (p= 0,5986) teniendo en cuenta el factor de los DD. El patrón de fractura predominante sobre la dentina fue el cohesivo. El uso previo y prolongado de diferente DD no afectó resistencia de unión a la dentina promovido por un sistema adhesivo de autograbado.

Bleaching procedures can interfere on adhesive bonding of methacrylate-based restorative materials. After introduction of silorane-based composites, little information is available about this interaction. The objective is evaluate the influence of bleaching on enamel shear bond strength of silorane-based restorative system. Forty sound incisive bovine teeth were randomly divided into 04 groups (n= 10), being: G1 (control) not bleached + Clearfil SE Bond (CSEB)/Filtek Z250 (Z250), G2 (control) not bleached + Silorane Adhesive (SA)/Filtek P90 (P90), G3 bleached + CSEB/Z250; G4 bleached + SA/P90. The teeth were sectioned, had crowns included in a PVC rings, and the enamel surfaces gridded and polished with silicon carbide abrasive papers. G1 and G2 were stored in artificial saliva (37 C), daily renewed, for a period of 04 days. G3 and G4 were exposed to 02 sessions of 38% hydrogen peroxide (38HP), with 03 applications of 15 min in each session. Composite resin cylinders were built up on the enamel surfaces. Bonding procedures were performed according the manufacturer's instructions. After storage in distilled water for 24 h (37 C), the samples were submitted to shear bond test. Data were analyzed by two-way ANOVA and t (LSD) tests (5%). Intra group comparison showed significant difference for Z250 after bleaching, but not for P90. Shear strength was significant lower for P90, despite bleaching procedures. In conclusion, 38HP bleaching had no influence on the enamel bond strength of P90, even though presenting lower bond strength than Z250.

Los procedimientos de blanqueamiento dental pueden interferir en la unión adhesiva de los materiales de restauración a base de metacrilato. Después de la introducción de materiales compuestos a base de silorano, hay poca información disponible acerca de esta interacción. El objetivo fue evaluar la influencia del blanqueamiento en la cizalladura de la fuerza de adhesion sobre esmalte del sistema restaurativo a base de silorano. Cuarenta dientes incisivos bovinos fueron divididos aleatoriamente en 4 grupos (n= 10), siendo: G1 (control) - no aclarado + Clearfil SE Bond (CSEB)/Filtek Z250 (z250), G2 (control) - no aclarado + adhesivo de silorane (AS)/Filtek P90 (P90), G3 - aclarado + CSEB / Z250; g4 - aclarado + AS/P90. Los dientes fueron seccionados, tenían coronas incluidas en anillos de pvc, y las superficies de esmalte fueron molidas y pulidas con papeles abrasivos de silicona de silicio. G1 y G2 fueron almacenados en saliva artificial (37 °C), renovada diariamente, durante un período de 04 días. G3 y G4 se expusieron a 2 sesiones de peróxido de hidrógeno al 38% (38 HP) con 03 aplicaciones de 15 min en cada sesión. Los cilindros de resina compuesta fueron construidos en las superficies de esmalte. Los procedimientos de unión se realizaron según las instrucciones del fabricante. Después del almacenamiento en agua destilada durante 24 h (37 °C), las muestras fueron sometidas al ensayo de resistencia de adhesión al cizallamiento. Los datos fueron analizados por ANOVA de dos vías y prueba t (5%). La comparación intragrupo mostró diferencias significativas para Z250 después del aclaramiento, pero no para P90. La resistencia al corte fue significativamente menor para P90, a pesar de los procedimientos de blanqueamiento. En conclusión, el blanqueamiento con 38HP no tuvo influencia en la resistencia de la unión esmalte de P90, a pesar de presentar una fuerza de unión más baja que Z250.

The ethanol wet-bonding technique (EWBT) was introduced in an attempt to overcome the problems caused by high hydrophilicity and/or incomplete penetration of most commercially available adhesive systems. This strategy provides better conditions for the inter-diffusion of hydrophobic dentin monomers. Today, there are many EWBT protocols, which yield bonding interfaces with minimal degradation and longer durability compared with commercial hydrophilic adhesive systems. The aim of this review is to discuss in greater detail the EWBT, focused on the following aspects: dentin saturation, hydrophobic primer preparation, inactivation of metalloproteinases (MMPs), dentin biomimetic remineralization and the clinical perspectives of this technique. The present review on the EWBT provides support for a better understanding of the behavior of dentin when exposed to dehydration and hydrophobic monomer interaction. Moreover, additional studies are suggested to investigate the long-term stability of this type of hybrid layer.

La técnica de la adhesión húmeda en etanol (TAHE) se introdujo en un intento de superar los problemas causados por la alta hidrofilicidad y/o la penetración incompleta de la mayoría de los sistemas adhesivos disponibles comercialmente. Esta estrategia ofrece mejores condiciones para la interdifusión de monómeros dentinarios hidrofóbicos. Hoy en día, hay muchos protocolos TAHE que producen las interfaces de unión con mínima degradación y mayor durabilidad en comparación con los sistemas adhesivos hidrofilicos comerciales. El objetivo de esta revisión es discutir con más detalle la TAHE, explicando los siguientes aspectos relacionados: la saturación de la dentina, la preparación del primer hidrofóbico, la inactivación de las metaloproteinasas (MMP's), remineralización biomimética de la dentina, y las perspectivas clínicas de esta técnica. La presente revisión sobre la TAHE proporciona soporte para una mejor comprensión del comportamiento de la dentina cuando es expuesto a la deshidratación y la interacción con monómero hidrófobo. Además, se sugieren estudios adicionales para investigar la estabilidad a largo plazo de este tipo de camada híbrida.

INTRODUÇÃO: O clareamento dental representa uma manobra conservadora na recuperação estética de dentes com alterações cromáticas. Contudo, os tratamentos clareadores são passíveis de causar efeitos adversos, quando não bem planejados e executados. OBJETIVO: Este estudo avaliou a influência do gel clareador no aumento da temperatura intra-câmara pulpar através da técnica de clareamento dental fotoativado realizado em consultório. MATERIAL E MÉTODO: Um incisivo central superior humano foi seccionado na porção radicular 3 mm abaixo da junção cemento-esmalte. O canal radicular foi alargado para permitir a introdução do sensor do termômetro na câmara pulpar, a qual foi preenchida com pasta térmica, favorecendo a transferência de calor das paredes dentárias para o sensor do termômetro digital com termopar tipo K (MT- 401A) durante o clareamento. Três agentes clareadores fotossensíveis (peróxido de hidrogênio a 35%) foram utilizados, sendo: Whiteness HP (FGM), Whiteness HP Maxx (FGM) e Lase Peroxide Sensy (DMC). Um aparelho fotopolimerizador de led (Flash Lite - Discus Dental) foi empregado para a ativação dos géis clareadores. Seis ciclos de clareamento foram realizados para cada grupo testado. Os resultados foram submetidos à ANOVA de um critério e ao teste t (LSD) (α<0,05). RESULTADO: A menor média de variação de temperatura (ºC) foi observada com o Lase Peroxide Sensy (0,20), enquanto que a maior com o Whiteness HP (1,50). CONCLUSÃO: Os géis clareadores Whiteness HP e Whiteness HP Maxx interferiram significativamente no aumento da temperatura intra-câmara pulpar durante o clareamento, sendo esta variação dependente do tipo de gel clareador empregado.

INTRODUCTION: Dental bleaching is a conservative method for the aesthetic restoration of stained teeth. However, whitening treatments are likely to cause adverse effects when not well planned and executed. OBJECTIVE: This study evaluated the influence of whitening gel on temperature rise in the pulp chamber, using the in-office photoactivated dental bleaching technique. MATERIAL AND METHOD: The root portion of an upper central human incisor was sectioned 3mm below the cemento-enamel junction. The root canal was enlarged to permit the insertion of the K-type thermocouple sensor (MT-401) into the pulp chamber, which was filled with thermal paste to facilitate the transfer of heat during bleaching. Three photosensitive whitening agents (35% hydrogen peroxide) were used: Whiteness HP (FGM), Whiteness HP Maxx (FGM) and Lase Peroxide Sensy (DMC). An LED photocuring light (Flash Lite - Discus Dental) was used to activate the whitening gels. Six bleaching cycles were performed on each group tested. The results were submitted to one-way ANOVA and LSD t-test (α<0.05). RESULT: The lowest mean temperature variation (ºC) was detected for Lase Peroxide Sensy (0.20), while the highest was recorded for Whiteness HP (1.50). CONCLUSION: The Whiteness HP and Whiteness HP Maxx whitening gels significantly affected the temperature rise in the pulp chamber during bleaching, and this variation was dependent on the type of whitening gel used.

O objetivo deste ensaio clínico randomizado foi avaliar o comportamento clínico das restaurações adesivas, usando um adesivo convencional de três passos (CTP), um adesivo autocondicionante de um passo (AUP) e uma técnica simplificada da adesão úmida por etanol (AUET) antes da aplicação de uma resina composta em lesões cervicais não-cariosas. Noventa e três restaurações (31 para cada grupo) foram realizadas em 17 pacientes por um único operador. Nenhum preparo cavitário foi realizado. Depois de 6 e 12 meses, as restaurações foram avaliadas por 2 examinadores previamente treinados, utilizando critérios de Ryge modificados para retenção (kappa=1,00) e adaptação/manchamento marginal (kappa=0,81), e os resultados foram analisados pelos testes Exato de Fisher e Kruskal-Wallis, respectivamente. Não foram observadas diferenças significativas entre os grupos aos 6 e 12 meses para qualquer um dos critérios avaliados (p≥0,05). A análise intra-grupo feita pelos testes Q de Cochran (para retenção) e Wilcoxon (para adaptação/manchamento marginal) revelou diferenças significativas entre os intervalos de tempo baseline/12 meses para a adaptação marginal no AUP (p=0,0180) e manchamento marginal no CTP (p=0,0117). A análise de sobrevivência para o critério retenção realizada utilizando o teste de log-rank não apresentou diferenças significantes (p≥0,05). As restaurações feitas utilizando a técnica simplificada da adesão úmida por etanol comportaram-se igualmente às outras estratégias adesivas empregadas.

The objective of this randomized clinical trial was to evaluate the clinical performance of adhesive restorations using a three-step etch-and-rinse adhesive (TSER), a one-step self-etching adhesive (OSSE), and a simplified ethanol-wet bonding technique (EWBT) prior to the application of a composite resin in non-carious cervical lesions. Ninety-three restorations (31 for each group) were placed in 17 patients by a single operator. No cavity preparation was performed. After 6 and 12 months, the restorations were assessed by two previously trained examiners using modified Ryge criteria for retention (kappa=1.00) and marginal adaptation/staining (kappa=0.81), and the results were analyzed by Fisher's exact and Kruskal-Wallis tests, respectively. No significant differences were observed among groups at the 6- and 12-month time points for any of the assessed criteria (p≥0.05). The intra-group analysis performed by Cochran's test (for retention) and Wilcoxon test (for marginal adaptation/staining) revealed significant differences between the baseline/12-month time intervals in marginal adaptation in OSSE (p=0.0180) and in marginal staining in TSER (p=0.0117). The survival analysis for retention criteria performed using a log-rank test did not show significant differences (p>0.05). The restorations placed using the simplified EWBT performed equally well as the other adhesive strategies employed.

OBJETIVO: avaliar, in vitro, a influência do clareamento dentário com gel contendo fosfato de cálcio amorfo (ACP) na resistência da união adesiva de braquetes metálicos. MÉTODOS: trinta e seis dentes incisivos bovinos foram seccionados no limite coronorradicular e tiveram suas coroas incluídas em cilindros de PVC. Os corpos de prova foram divididos em três grupos (n = 12), de acordo com a realização do tratamento clareador e tipo de gel utilizado, sendo: G1 (controle) - sem clareamento; G2 - clareamento com gel sem ACP (Whiteness Perfect, FGM); G3 - clareamento com gel contendo ACP (Nite White ACP, Discus Dental). Os grupos G2 e G3 foram submetidos a 14 ciclos de clareamento, seguidos de intervalo de espera de 15 dias para a fixação adesiva dos braquetes metálicos. O ensaio mecânico de cisalhamento foi realizado em máquina universal Kratos, com velocidade de 0,5mm/min. Após o teste mecânico, os corpos de prova foram avaliados quanto ao índice de remanescente adesivo (ARI). Os resultados foram submetidos à ANOVA, ao teste de Tukey e ao de Kruskall-Wallis (α = 5%). RESULTADOS: diferenças significativas foram observadas entre os grupos testados. O grupo controle G1 (11,1MPa) mostrou uma resistência ao cisalhamento estatisticamente superior aos grupos submetidos ao clareamento (G2 = 5,40MPa; G3 = 3,73MPa), os quais não diferiram entre si. Não se observou diferença significativa para o ARI entre os grupos estudados. CONCLUSÃO: o clareamento dentário reduz a resistência da união adesiva de braquetes metálicos, enquanto a presença de ACP no gel clareador não influencia os resultados encontrados.

OBJECTIVE: To evaluate in vitro the effects of tooth whitening using gel with Amorphous Calcium Phosphate (ACP) on the bond strength of metal brackets. METHODS: Thirty-six bovine incisors were sectioned at the crown-root interface, and the crowns were then placed in PVC cylinders. The specimens were divided into 3 groups (n = 12) according to whitening treatment and type of gel used, as follows: G1 (control) = no whitening; G2 = whitening with gel not containing ACP (Whiteness Perfect - FGM), G3 = whitening with gel containing ACP (Nite White ACP - Discus Dental). Groups G2 and G3 were subjected to 14 cycles of whitening followed by an interval of 15 days before the bonding of metal brackets. Shear bond strength testing was performed on a Kratos universal test machine at a speed of 0.5 mm/min. After the mechanical test, the specimens were assessed to determine the adhesive remnant index (ARI). The results were subjected to ANOVA, Tukey's test and Kruskal-Wallis test (5%). RESULTS: Significant differences were noted between the groups. Control group (G1 = 11.10 MPa) showed a statistically higher shear bond strength than the groups that underwent whitening (G2 = 5.40 Mpa, G3 = 3.73 MPa), which did not differ from each other. There were no significant differences between the groups in terms of ARI. CONCLUSION: Tooth whitening reduces the bond strength of metal brackets, whereas the presence of ACP in the whitening gel has no bearing on the results.

Este estudo avaliou a influência do tipo de fonte fotopolimerizadora na resistência ao cisalhamento da união adesiva ao esmalte clareado com peróxido de carbamida a 10%. Setenta e dois dentes incisivos bovinos íntegros foram divididos em 6 grupos (n=12) de acordo com a realização ou não do tratamento clareador e com a fonte fotoativadora empregada: G1 - clareamento/luz halógena; G2 - sem clareamento (controle)/luz halógena; G3 - clareamento/LED; G4 - sem clareamento (controle)/LED; G5 - clareamento/arco de plasma de xenônio; G6 - sem clareamento/arco de plasma de xenônio. Os grupos experimentais foram submetidos ao clareamento por um período de 14 dias, com exposição diária 4 horas. Os grupos controle foram armazenados em saliva artificial, a 37ºC, por período igual ao clareamento. A união da resina composta ao esmalte obedeceu às recomendações dos fabricantes. Em seguida, todos os corpos de prova foram armazenados em água destilada, por 24 horas, a 37ºC, até a realização do ensaio de resistência ao cisalhamento. O maior valor médio de resistência (14,86 MPa) foi obtido para o grupo G2, e o menor para o grupo G5 (12,32 MPa). A comparação dos grupos através da análise de variância (ANOVA 2-way) demonstrou não haver diferenças significativas para ambos os fatores considerados neste estudo (clareamento e tipo de fonte fotopolimerizadora), bem como para a interação entre estes. Sendo assim, foi possível concluir que o clareamento do esmalte bem como o tipo de fonte fotopolimerizadora utilizada, não interferiram na resistência da união adesiva a este substrato.

This study evaluated the influence of 3 different photopolymerization sources on enamel shear bond strength after bleaching with 10% carbamide peroxide. Seventy-two incisive bovine teeth were randomly divided into 6 groups (n=12) according to bleaching treatment and photopolymerization source used: G1 - Bleached / Halogen lamp; G2 - Not bleached / Halogen lamp (control); G3 - Bleached / Light-emitting diodes (LED); G4 - Not bleached / Light-emitting diodes (LED) (control); G5 - Bleached / Xenon plasma arc; G6 - Not bleached / Xenon plasma arc (control). Experimental groups were exposed to bleaching agent for a period of 14 days, with a daily contact of 4 h and then stored in artificial saliva at 37ºC. Control groups were stored in artificial saliva at 37ºC for same period of bleaching treatment. Procedures for bonding composite resin to enamel were carried out according to manufacturer instructions. After storage in distilled water at 37ºC for 24 hours, all samples were submitted to shear bond strength test. G2 had the highest mean value (14.86 MPa) while G5 had the lowest (12.32 MPa). The comparison of groups by 2-way ANOVA showed that there were no significant differences for either of the factors considered in this study (bleaching and photopolymerization source), hence the interaction between these factors. It was therefore possible to conclude that neither enamel bleaching nor the photopolymerization source used had any influence on enamel shear bond strength.