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.

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.

An increase in dentin roughness, associated with surface composition, contributes to bacterial adherence in recontaminations. Surface roughness is also important for micromechanical interlocking of dental materials to dentin, and understanding the characteristics of the surface is essential to obtain the adhesion of root canal sealers that have different physico-chemical characteristics. OBJECTIVES: To evaluate the effects of sodium hypochlorite (NaOCl), ethylenediaminetetraacetic (EDTA), etidronic (HEBP), and citric acid (CA) associated with different irrigation regimens on root dentin roughness. MATERIAL AND METHODS: Forty-five root halves of anterior teeth were used. The root parts were sectioned in thirds, embedded in acrylic resin and polished to a standard surface roughness. Initially, the samples of each third were randomly assigned into 3 groups and treated as follows: G1 - saline solution (control); G2 - 5% NaOCl+18% HEBP mixed in equal parts; and G3 - 2.5% NaOCl. After initial measuments, the G3 samples were distributed into subgroups G4, G5 and G6, which were subjected to 17% EDTA, 10% CA and 9% HEBP, respectively. Following the new measuments, these groups received a final flush with 2.5% NaOCl, producing G7, G8 and G9. The dentin surface roughness (Ra) was determined before and after treatments using a profilometer. The Wilcoxon test (α<0.05) was used to compare the values before and after treatments, and the Friedman test (α<0.05) to detect any differences among root thirds. RESULTS: (i) NaOCl did not affect the surface roughness; (ii) there was a significant increase in roughness after the use of chelating agents (P<0.01); and (iii) only the G3 group showed a difference in surface roughness between apical third and other thirds of the teeth (P<0.0043). CONCLUSION: Only the irrigation regimens that used chelating agents altered the roughness of root dentin.

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.

The present investigation observed the sealing ability of low shrinkage composite resins in large and deep cavities, placed and photocured in one increment. Large, deep cavities (5.0 mm diameter and 2.5 mm deep) surrounded by enamel were prepared in bovine teeth, which were then divided into five groups. Groups 1, 2, 3 and 4: acid conditioning + Adper Single Bond (3M/ESPE, St Paul, MN, USA) and restoration with Aelite LS Posterior (BISCO Inc. Schaumburg, IL, USA) (G1); Filtek Z-350 (3M/ESPE,St Paul, MN, USA) (G2); Filtek Z-350 Flow (3M/ESPE, St Paul, MN, USA) (G3); Premisa (KERR Corporation, Orange, CA, USA) (G4). Group 5: Silorane Adhesive system (3M/ESPE, St Paul, MN, USA) + restoration with Filtek Low Shrinkage Posterior P90 (3M/ESPE, St Paul, MN, USA). After polymerization, the teeth were immersed in 0.5% basic fuchsine solution and immediately washed. Using the Imagetool Software, the extent of dye along the margins was calculated as a percentage of total perimeter. The restorations were then transversally sectioned and the depth of dye penetration was calculated in mm, using the same software. Kruskal-Wallis analysis for all groups showed no statistical differences for extent (p = 0.54) or depth (p = 0.8364) of dye penetration. According to this methodology, the so-called low shrinkage composite resins had the same sealing ability compared to regular and flowable nanocomposite materials.

The present clinical study aimed to assess the postoperative sensitivity (POS) after 48 hours and seven days in occlusal restorations bonded with three different adhesive systems, two of them containing glutaraldehyde. The restorative procedures were performed using the three-step etch-and-rinse Adper SBMP-Plus adhesive (SBMP), the two-step etch-and-rinse Gluma Comfort One Bond + Desensitizer adhesive (GC+D) and the all-in-one self-etching/priming I Bond (IB) adhesive, which also has glutaraldehyde in its formula. All cavities were restored with Filtek Supreme nanoparticle composite resin. After 48 hours and seven days the patients were recalled and the postoperative sensitivity evaluated. The data analyzed by non-parametric Friedman test showed no significant differences in POS among the three tested groups after 48 hours and seven days.

This literature review article addresses the types and the main components of different etch-and-rinse and self-etch adhesive systems available in the market, and relates them to their function, possible chemical interactions and infuence of handling characteristics. Scanning electron microscopy (SEM) images are presented to characterize the interface between adhesives and dentin. Adhesive systems have been recently classifed according to their adhesion approaches in etch-and-rinse, self-etch and glass ionomer. The etch-and-rinse systems require a specifc acid-etch procedure and may be performed in two or three steps. Self-etch systems employ acidic monomers that demineralize and impregnate dental substrates almost at the same time. These systems are separated in one or two steps. Some advantages and defciencies were noted for etch-and-rinse and self-etch approaches, mainly for the simplifed ones due to some chemical associations and interactions. The SEM micrographs illustrate different relationships between adhesive systems and dental structures, particularly dentin. The knowledge of composition, characteristics and mechanisms of adhesion of each adhesive system is of fundamental importance to permit the adoption of ideal bonding strategies under clinical conditions.

O objetivo deste estudo foi determinar o efeito da polimerização gradual, mediante a utilização de aparelhos de Quartzo-Tungustênio-Halógena (QTH) e Arco de Plasma de Xenônio (PAC), no selamento marginal de restaurações classe V em resina composta com margens localizadas em dentina. Setenta e cinco incisivos bovinos receberam preparos de cavidades classe V, na raiz, com o intuito de situar as margens cavitárias em dentina. Os dentes foram divididos em cinco grupos de acordo com o método de fotoativação. As cavidades, depois de condicionadas, foram tratadas com o sistema adesivo Single Bond (3M Dental) e restauradas com a resina composta Z100 (3M Dental) pela técnica incremental. A fotoativação foi realizada para cada grupo como descrito a seguir: Grupo I: PAC pelo método de fotoativação constante: 1600mW/cm² - 3s; Grupo II: PAC pelo método de fotoativação por passos (800mW/cm² - 2s, subindo automaticamente para 1600mW/cm² - 4s); Grupo III: QTH pelo método de fotoativação constante: 400 mW/cm² - 40s; Grupo IV: QTH pelo método de fotoativação em rampa: 100 a 600 mW/cm² - 15s, permanecendo a 600mW/cm2 por mais 25s; Grupo V: QTH pelo método de fotoativação por pulso: 200 mW/cm² - 3s, tempo de espera de 3min.e a seguir 600mW/cm² - 30s. Os dentes foram armazenados em água destilada a 37ºC por 30 dias e então submetidos à ciclagem térmica, por 500 ciclos à 5 ºC e 55 ºC. Os ápices dos dentes foram selados com resina composta e os dentes foram cobertos com duas camadas de esmalte para unha, antes da sua imersão em fucsina básica a 0,5%. Os dentes foram seccionados e os cortes foram escaneados para avaliação da área infiltrada por corante por um programa de computador (Image Tools). Os cortes foram também visualizados com lupa para a determinação do grau de penetração do corante na interface dente-restauração por escores. Diferenças estatisticamente significantes foram observadas entre os grupos quanto ao grau e à área de penetração de corante (p < 0,05). Os grupos I e II apresentaram valores significantemente mais altos de infiltração e penetração do corante que os grupos III, IV e V. Em conclusão, o uso da fonte de PAC, no modo constante e por passos, resultou em valores significantemente maiores de infiltração marginal quando comparados com a intensidade de luz média emitida pelos aparelhos de QTH. Os métodos de fotoativação por pulso, rampa e continuo com a fonte de QTH resultaram num grau similar de microinfiltração.

The aim of this study was to determine the effect of a softstart polymerization method from Quartz-Tungsten-Halogen (QTH) and Plasma Arc (PAC) curing units on microleakage of Class V composite resin restorations with dentin cavosurface margins. Seventy-five bovine incisors received standardized class V cavities in all dentin margins. Teeth were divided into 5 equal groups according to the curing cycle. The cavities were incrementally restored with a composite resin (Single Bond/Z-100, 3M). Light curing was applied as follows: Group I: PAC light continuous-cycle curing at 1600 mW/cm² for 3s; Group II: PAC light step-cycle curing (2s at 800 mW/cm² then 4s at 1600 mW/cm²); Group III: QTH light continuous-cycle curing at 400 mW/cm² for 40s; Group IV: QTH light ramp-cycle curing (from 100 to 600 mW/cm² in 15s followed by 25s at 600 mW/cm²); Group V: QTH light pulse-delay curing (200 mW/cm² for 3s followed by 3 min delay then 600 mW/cm² for 30s). Teeth were stored in distilled water at 37ºC for 30 days and then subjected to thermocycling for 500 cycles at 5 and 55ºC. Root apices were sealed and teeth coated with nail varnish before they were immersed in 0.5% fuchsine red dye solution. Teeth were then sectioned and slices were scanned with a computer scanner to determine the area of dye leakage using a computer program (Image Tools). Images of tooth slices were also visually examined under magnification and dye penetration along the tooth/restoration interface was scored. Significant differences in the degree of dye penetration and leakage were detected between groups (p<.05). Groups I and II had significantly higher values of dye penetration and leakage than groups III, IV and V. In conclusion, the use of PAC light curing in a continuous or step cycle modes resulted in increased microleakage of Class V resin composite restorations compared with medium intensity QTH light curing. Pulse, ramp and continuous-cycle curing modes with QTH light resulted in similar degrees of microleakage.

A reabsorção cervical externa da raiz é uma das desvantagens do procedimento clareador. Vários são os mecanismos que podem ser responsáveis por desencadear esta reabsorção, dentre eles, a ação química e física dos materiais utilizados, bem como a morfologia da junção amelocementária. Este trabalho teve como objetivo observar uma possível via de comunicação entre a câmara pulpar e a superfície externa da raiz, medindo o pH e a infiltração de corante na dentina cervical após o procedimento clareador. Realizou-se o tratamento endodôntico em 34 dentes incisivos permanentes. Os dentes foram divididos em 3 grupos experimentais de acordo com o nível do corte da obturação e selamento da embocadura dos canais com cimento de ionômero de vidro. O clareamento foi realizado usando perborato de sódio e peróxido de hidrogênio a 30%. As leituras do pH foram realizadas após 30 min, 24 h, 48 h e 72 h do início do procedimento. A seguir, os dentes foram imersos em fucsina básica a 0,5% por 24 h para determinarmos possíveis diferenças na permeabilidade da dentina cervical. Os resultados mostraram que o pH apresentou tendência a se modificar quando o corte da obturação permaneceu na embocadura dos canais, bem como quando se removeram 2 mm da obturação e quando se selou a embocadura com cimento de ionômero de vidro. A permeabilidade dentinária aumentou nos 3 grupos experimentais, em comparação com os dentes que compreenderam o grupo controle. Estas leves diferenças podem sugerir uma via de comunicação entre a câmara pulpar e a superfície externa da raiz.

External cervical root resorption is one of the disadvantages of the bleaching procedure. There are several mechanisms that may be responsible for causing resorption, such as the chemical and physical action of the utilized materials and the morphology of the cementoenamel junction. The purpose of this study was to investigate the presence of a communication between the pulp chamber and the external root surface. The investigation was carried out by means of pH tests and measurement of dye infiltration into cervical dentin after the bleaching procedure. Thirty-four human permanent incisors were submitted to endodontic treatment. The teeth were assigned to three experimental groups, according to the level at which the filling was cut, and to the sealing of the root canal entrance with glass ionomer cement. Sodium perborate and 30% hydrogen peroxide were utilized for bleaching. pH readings were carried out after 30 minutes, 24 h, 48 h and 72 h from the beginning of the procedure. The teeth were immersed in 0.5% basic fuchsin for 24 h in order to determine possible differences in the permeability of cervical dentin. The results revealed that pH tended to change when the root filling was cut at the entrance of the canal, when 2 mm of the filling were removed, and when the canal entrance was sealed with glass ionomer. Dentinal permeability increased in the three experimental groups, in comparison with the control group. These slight differences may suggest a communication between the pulp chamber and the external root surface.