RESUMO Objetivo: Avaliar a de resistência de união da interface adesiva associada a uma camada hidrofóbica extra de selamento, e comparar após três e seis meses de armazenamento em água destilada. Métodos: Foram utilizados 12 terceiros molares humanos extraídos hígidos (n=6), que foram divididos em dois grupos, sendo grupo SB - controle - autocondicionante; e grupo SBHidrof - autocondicionante associado à camada hidrofóbica (Adhesive layer, 3m ESPE). Após restauração incremental com resina composta (Opalis, FGM), os dentes foram fatiados para obtenção de espécimes (1mm2) e em seguida, submetidos à máquina de ensaio universal (INSTRON 1mm/min.) imediato e após três e seis meses. Os dados obtidos foram submetidos à normalidade (Shapiro Wilk), e análise comparativa ANOVA (dois fatores: técnica e tempo) e Tukey (p<0,05). Resultados: Nos valores imediatos não houve diferença estatisticamente significante (p>0,05), porém após três e seis meses de imersão dos espécimes, em água destilada, foi observado manutenção dos valores de resistência de união no grupo que recebeu a camada hidrofóbica (p<0,05). Conclusão: Ao incorporar uma camada hidrofóbica sobre um sistema adesivo universal, foi possível preservar a longevidade da adesão dentinária.

ABSTRACT Objective: evaluate bond strength of a universal adhesive, associated to an extra hydrophobic sealing layer, and compare after three and six months immersed in distilled water. Methods: After ethical approval of the CEP / HUUFMA, 12 human third molars (n = 6) were extracted, which were divided into two groups: SB - control group - selfetching; and SBHidrof - selfetching group associated to the hydrophobic layer (Adhesive layer, 3m ESPE). After incremental restoration with composite resin (Opalis, FGM), the teeth were sliced to obtain specimens (1mm2) and then submitted to the universal test machine (INSTRON 1mm / min.), immediate and after three and six months. The data were submitted to normality (Shapiro Wilk), and comparative Analysis of variance (two ways: technique and time) and Tukey (p <0.05). Results Immediate values showed no statistically significant difference (p> 0.05), but after three and six months of immersion of the specimens, in distilled water, bond strength values were maintained in the group that received the hydrophobic layer (p<0.05). Conclusion: It was observed that, by incorporating a hydrophobic layer on a universal adhesive system, it was possible to preserve dentin adhesion.

Abstract This study evaluated microtensile bond strength (µTBS), degree of conversion, modulus of elasticity and ultramicrohardness of three etch-and-rinse adhesives systems. The materials evaluated were: Ambar (FGM), Optibond (Kerr) and Magic Bond (Vigodent). The degree of conversion was analyzed by FTIR/ATR. To evaluate bond strength (μTBS) in dentin, 15 teeth (n = 5) were restored and sliced to obtain the specimens (0.8mm2). The dynamic ultra microhardness tester was used to evaluate the hardness and modulus of elasticity. The Magic Bond adhesive system showed lower µTBS than Ambar and Optibond (p <0.001). For degree of conversion, comparisons between groups of adhesive systems evaluated showed statistically significant difference (p<0.001), with higher values for Ambar and Optibond when compared a Magic Bond. For modulus of elasticity and ultramicrohardness, Ambar and Magic Bond showed lower values than Optibond. The best results in all properties evaluated were obtained by the Optibond adhesive system.

Resumo Avaliar o efeito da incorporação de vidro niobofosfato bioativo (NbG, 40% em peso) em dois sistemas adesivos simplificados convencionais (One Step [OS] e Prime & Bond {PB}) com e sem silano, no grau de conversão (%) e resistência de união (RU) após 6 meses. Os seguintes grupos foram testados: Controle OS: sem adição de partículas; OS e adição de NbG sem silano (OSNbG); OS e adição de partículas silanizadas NbG (OSNbGS); Controle PB: sem adição de partículas; PB e adição de partículas de NbG sem silano (PBNbG); PB e adição de partículas silanizadas NbG (PBNbGS). O grau de conversão (GC) foi determinado utilizando espectroscopia de Fourier (FTIR/ATR). Para RU, 48 terceiros molares humanos (n=8) foram restaurados e cortados para obter corpos-de-prova (0,8 mm2) e, em seguida, testados em dois momentos: imediato e após seis meses. O padrão de fratura foi avaliado com lupa estereoscópica (40×) e microscópio eletrônico de varredura (MEV). Os dados foram submetidos à análise de variância e Tukey (a=0,05). NbG não comprometeu valores de GC dos sistemas adesivos (p>0,05). Além disso, a adição de NbG aos sistemas adesivos não afetou os valores de RU (p>0,05). O padrão de fratura ocorreu predominantemente na interface dentina-adesivo. NbG não afetou os resultados de GC e RU.

Abstract To evaluate the effect of incorporating niobium phosphate bioactive glass (NbG) into commercial etch-and-rinse adhesive systems, with and without silane, on their degree of conversion (DC) (%) and microtensile bond strength (μTBS). The NbG micro-filler was added to two etch-and-rinse adhesive systems: One Step (OS) and Prime & Bond (PB) at 40% concentration. The following groups were formed: control without glass addition OS; addition of unsilanized NbG (OSNbG); addition of silanized NbG (OSNbGS); control without glass PB; addition of unsilanized NbG (PBNbG); addition of silanized NbG (PBNbGS). The DC was determined using total Fourier spectroscopy reflection (FTIR/ATR). For μTBS testing, 48 human third molars (n=8) were restored and sliced to obtain specimens (0.8 mm2) and they were tested at two different time intervals: immediately and after 6 months. The fracture mode was evaluated with a stereoscopic loupe (40×) and by scanning electron microscopy (SEM). The data were subjected to ANOVA and Tukey tests (a=0.05). NbG addition did not compromise the adhesive system DC values (p>0.05). Furthermore, the NbG added to the adhesive systems did not affect μTBS values (p>0.05). Fracture occurred predominantly at the dentin-adhesive interface. NbG bioactive glass did not affect the DC or microtensile bond strength results.

The aim of this study was to evaluate the pH, ultimate tensile strength (UTS), and micro-shear bond strength (µSBS) of two self-adhesive resin cements to enamel and dentin. Sound bovine incisors (n = 10) and two self-adhesive resin cements (i.e., RelyX U-100 and seT PP) were used. The pH of the resin cements was measured using a pH-indicator paper (n = 3). Specimens for UTS were obtained from an hourglass-shaped mold. For µSBS, cylinders with internal diameter of 0.75 mm and height of 0.5 mm were bonded to the flat enamel and dentin surfaces. Bonded cylinders were tested in the shear mode using a loop wire. The fracture mode was also evaluated. The cement seT PP showed a low pH; U-100 showed significantly higher UTS (49.9 ± 2.0) than seT PP (40.0 ± 2.1) (p < 0.05) and high µSBS to enamel (10.7 ± 3.7). The lowest µSBS was found for seT PP to dentin (0.7 ± 0.6); seT PP to enamel (4.8 ± 1.7), and for U-100 to dentin (7.2 ± 1.9), showing an intermediate µSBS value (p < 0.05). Adhesive failure was the most frequently observed failure mode. The resin cement that presented the lowest pH and UTS also presented the lowest micro-shear bond strength to enamel and dentin.

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.

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.