Resumo Introdução O correto uso de pinos de fibra de vidro em dentes tratados endodonticamente é essencial para o sucesso clínico do tratamento restaurador. Objetivo Esse estudo avaliou a resistência ao cisalhamento por extrusão (push-out) em pinos de fibra de vidro reembasados (R) ou não reembasados (NR), cimentados com cimento resinoso auto-adesivo [RelyXTM U100 (U100)] e cimento resinoso convencional [RelyXTM ARC (ARC)]. Material e método Sessenta dentes humanos unirradiculares foram tratados endodonticamente e divididos nos grupos ARC-NR; U100-NR; ARC-R; U100-R. Os dentes foram seccionados nos terços cervical, médio e apical para serem submetidos ao teste de cisalhamento por extrusão (push-out). A resistência de união foi analisada pelo teste de Friedman; os tipos de cimento e de pinos foram comparados pelo teste de Mann Whitney. O padrão de falhas foi avaliado com câmera digital através de imagens em 200x de ampliação e foi classificado como falhas adesivas (na interface cimento/dentina ou cimento/pino), coesivas (cimento ou pino), e mistas. Resultado No grupo ARC-NR, os valores de resistência de união foram maiores no terço cervical; os grupos U100-NR e ARC-R foram semelhantes entre os terços. No grupo U100-R, os valores de resistência de união foram semelhantes nos terços cervical e médio, e houve menor valor no terço apical. Para pinos de fibra de vidro não reembasados, a média mais alta dos valores de resistência de união foi com cimento resinoso auto-adesivo. Considera-se ainda que os pinos reembasados com cimento resinoso convencional tiveram camada de cimento mais forte em comparação com os pinos de fibra não reembasados. Conclusão A técnica do pino reembasado foi eficiente no grupo ARC-R. Os grupos ARC-NR e U100-R mostraram melhor resistência de união na região cervical das paredes do canal radicular. As principais falhas foram adesivas na interface cimento-pino.

Abstract Introduction The correct use of glass fiber posts in endodontically treated teeth is essential for the clinical success of restorative treatment. Objective This study evaluated the push-out shear bond strength of relined (R) or non-relined (NR) glass fiber posts, cemented with self-adhesive resin cement [RelyXTM U100 (U100)] and conventional resin cement [RelyXTM ARC (ARC)]. Material and method Sixty human single-rooted teeth were endodontically treated and divided into ARC-NR; U100-NR; ARC-R; U100-R groups. The teeth were sectioned into cervical, middle and apical thirds, and subjected to the push-out test. Bond strength was analyzed by the Friedman test; cement and post types were compared by the Mann Whitney test. The pattern of failures was evaluated with digital camera through images at 200x magnification, and was classified as adhesive (at the cement/dentin or cement/post interface), cohesive (cement or post), and mixed failures. Result In ARC-NR, bond strength values were higher in the cervical third; in U100-NR and ARC-R they were similar between the thirds. In U100-R, in the cervical and middle thirds the bond strength values were similar, and there was lower value in the apical third. For non-relined glass fiber posts, the highest mean bond strength values were observed with self-adhesive resin cement. Whereas, relined posts cemented with conventional resin cement had stronger cement layer in comparison with non-relined fiber posts. Conclusion The post relining technique was efficient in ARC-R. ARC-NR and U100-R showed improved bond strength in the cervical region of canal walls. The main failures were adhesive at the cement-post interface.

Objetivo: Avaliar o efeito de diferentes tratamentos de superfície, na resistência de união de reparo em um compósito à base de silorano envelhecido. Métodos: Foram confeccionados espécimes de compósito a base de silorano (P90, 3M/ESPE), envelhecidos com termociclagem (10.000 ciclos, 5-55ºC) e aleatoriamente submetidos a diferentes tratamentos de superfície (cada grupo n= 24): grupo controle (sem reparo); grupo 1 (só aplicação do adesivo do P90); grupo 2 (asperização com ponta diamantada + adesivo do P90); grupo 3 (jateamento com óxido de alumínio + adesivo do P90) e grupo 4 (asperização e jateamento + adesivo do P90). Em seguida, os espécimes foram reparados com o mesmo compósito de silorano e cada grupo subdivididos aleatoriamente em 2 subgrupos: armazenados em água destilada à 37 °C por 7 dias ou submetidos termociclagem (5.000 ciclos). Após o envelhecimento, foi realizado o teste de tração. Os dados foram submetidos à análise de variância a dois fatores (ANOVA 2-way). Resultados: Os grupos reparados que foram submetidos ao envelhecimento de 7 dias em estufa não diferiram estatisticamente (p>0,05) dos grupos correspondentes envelhecidos com termociclagem. A resistência de união dos espécimes foi significativamente influenciada pelo tratamento superficial (p<0,01). Os maiores valores de resistência à tração foram encontrados nos grupos 3 (20,76 ± 4,51 MPa) e 4 (20,67± 3,96 MPa), independente do envelhecimento ou do reparo. Conclusão: O reparo de compósito à base de silorano se mostrou estável após envelhecimento e o tratamento superficial com jateamento de óxido de alumínio foi o mais efetivo.

Objective: To evaluate the effects of different surface treatments, in repair bond strength of an aged silorane-based composite. Methods: Specimens were made of a silorane-based composite (P90, 3M/ESPE), aged with thermal-cycling (10,000 cycles; 5-55ºC) and randomly submitted to different surface treatments (each group n = 24): control group (no repair); group 1 (only application of P90 adhesive); group 2 (diamond bur asperization + P90 adhesive); group 3 (aluminum oxide sandblasting + P90 adhesive) and group 4 (asperization + sandblasting + P90 adhesive). Then, the specimens were repaired with the same silorane-based composite and each group randomly subdivided into 2 subgroups: stored in distilled water at 37 °C for 7 days or submitted to thermal-cycling (5,000 cycles). After aging, the tensile test was carried out. The data was submitted to 2-way analysis of variance (2-way ANOVA). Results: The repaired groups aged with oven storage for 7 days did not statistically differ (p>0.05) from the corresponding groups aged with thermal-cycling. The bond strength of the specimens was significantly influenced by the superficial treatment (p<0.01). The highest values of tensile bond strength were found in groups 3 (20.76 ± 4.51 MPa) and 4 (20.67± 3.96 MPa), regardless of aging and repair. Conclusion: The repair of silorane-based composite showed to be stable after aging, and the superficial treatment with aluminum oxide sandblasting was the most effective.

During post preparation, the root canal is exposed to the oral cavity, and endodontic treatment may fail because of coronal leakage, bacterial infection and sealing inability of the luting cement. OBJECTIVE: this study quantified the interfacial continuity produced with conventional dual-cure and self-adhesive resin cements in the cervical (C), medium (M) and apical (A) thirds of the root. MATERIAL AND METHODS: Forty single-rooted human teeth were restored using Reforpost # 01 conical glass-fiber posts and different materials (N=10 per group): group AC=Adper™ ScotchBond™ Multi-purpose Plus + AllCem; group ARC=Adper™ ScotchBond™ Multi-purpose Plus + RelyX ARC; group U100=RelyX U100; and group MXC=Maxcem Elite. After being kept in 100% humidity at 37°C for 72 hours, the samples were sectioned parallel to their longitudinal axis and positive epoxy resin replicas were made. The scanning electron micrographs of each third section of the teeth were combined using Image Analyst software and measured with AutoCAD-2002. We obtained percentage values of the interfacial continuity. RESULTS: Interfacial continuity was similar in the apical, medium and cervical thirds of the roots within the groups (Friedman test, p>0.05). Comparison of the different cements in a same root third showed that interfacial continuity was lower in MXC (C=45.5%; M=48.5%; A=47.3%) than in AC (C=85.9%, M=81.8% and A=76.0%), ARC (C=83.8%, M=82.4% and A=75.0%) and U100 (C=84.1%, M=82.4% and A=77.3%) (Kruskal-Wallis test, p<0.05). CONCLUSIONS: Allcem, Rely X ARC and U100 provide the best cementation; cementation was similar among root portions; in practical terms, U100 is the best resin because it combines good cementation and easy application and none of the cements provides complete interfacial continuity.

Glass ionomer based materials are clinically popular in several areas of restorative dentistry, but restoration of cervical lesions has proven particularly successful. Various etiologies, conformations, locations and structural characteristics make non-carious cervical lesions more challenging to adhesive restorative procedures and marginal seal in the long run. Due to their characteristics, glass ionomer cements (GICs) have precise indication for these cases. Moreover, the use of a GIC base underneath composite resin, the so-called "sandwich" or mixed technique, allows associating the good characteristics of composite resins and GICs, and has been considered quite useful in the restoration of non-carious cervical defects. The aim of this paper is to critically review the literature and discuss peculiar features of GICs regarding their role in the restoration of non-carious cervical lesions.