This study analyzed the bond strength (BS) of HEMA versus HEMA-free self-etch adhesive systems to dentin. The occlusal surface of 20 third molars was removed and the dentin was abraded with 600-grit silicon carbide paper. The teeth were randomly assigned to 4 groups (n=5) and restored with GO, Adper SE Plus, OptiBond All-In-One, and Clearfil 3S Bond adhesive systems and Filtek Z350 composite. After light curing (600 mW/cm²), the teeth were stored in distilled water at 37ºC for 24 h and were sectioned in the mesiodistal and buccolingual directions to obtain sticks (0.8 mm²). The sticks were subjected to tensile force using a universal testing machine (0.5 mm/min), and the modes of failure were analyzed by scanning electron microscopy and classified as adhesive, cohesive, or mixed. The BS data (in MPa) were treated using one-way ANOVA and Tukey's tests at 5% significance. GO presented the lowest mean bond strength value (10.57 ± 3.72) and differed significantly from the other materials (p=0.001), which, in turn, presented statistically similar results (p>0.05) among themselves: Adper SE Plus (29.08 ± 8.93), OptiBond All-In-One (28.36 ± 6.49), and Clearfil 3S Bond (28.62 ± 6.97). Mixed fractures were the most prevalent. It was concluded that the influence of HEMA on BS to dentin was material dependent.

Under the conditions of this study, OptiBond FL was the best material to be used for sealing.

When introduced to the market, silorane-based materials promised less contraction compared to other materials. The purpose of this study was to evaluate the contraction stress, flexural strength, and elastic modulus of the Filtek Silorane composite with different photoactivation protocols. Filtek Silorane and Filtek Z350 composites were inserted in a circular photoelastic resin matrix and subjected to photoactivation at 650 mW cm 2 for 40 s (protocol I), 325 mW cm 2 for 80 s (protocol II), 100 mW cm 2 for 260 s (protocol III), 100 mW cm 2 for 5 s + 1 min delay +650 mW cm 2 for 39.5 s (protocol IV), or 100 mW cm 2 for 5 s + 3 min delay +650 mW cm 2 for 39.5 s (protocol V). Five samples were prepared for each resin with each photoactivation protocol. To determine contraction stress, fringes were analyzed in a polariscope. For flexural strength analyses, 25 specimens (10 × 2 × 2 mm) of each resin with each photoactivation protocol were submitted to the 3-point bending test in a universal testing machine. Data were submitted to ANOVA and post hoc Tukey's tests (α = 0.05). Filtek Silorane showed higher contraction stress results than Filtek Z350 for protocols II (16.4 ± 3.88 vs. 5.9 ± 1.64 MPa), IV (17 ± 2.67 vs. 8.8 ± 1.30 MPa), and V (16.3 ± 3.33 vs. 5.1 ± 1.95 MPa). Both resins showed similar flexural strength values, but the elastic modulus of Filtek Silorane was significantly higher with all photoactivation protocols. Pulse-delay photoactivation was effective for Filtek Z350, but not Filtek Silorane, because the elastic modulus and contraction stress were reduced for Filtek Z350 without any change in flexural strength.

Com advento das resinas compostas de segunda geração que apresentam características mecânicas e estéticas superiores às das resinas convencionais, principalmente com relação a resistência à abrasão, surge a possibilidade de utilizá-las associadas a fibras, como o sistema da Ivoclar Targis/Vectris. O objetivo deste trabalho foi apresentar a confecção de uma prótese adesiva livre de metal como resolução protética para a substituição do elemento dental 35, ausente. Paciente M.A.S., 38 anos, sexo feminino, buscou tratamento restaurador por motivo de estética e necessidade de substituição das restaurações antigas. Após anamnese, exame clínico, exame radiográfico e exame dos modelos de estudo foi proposto a reposição do elemento dental 35 através de prótese adesiva confeccionada em cerômero (Sistema Targis/Vectris. Foi realizado um repreparo do tipo onlay no elemento dental 34 e repreparo para coroa total do dente 36.  Após o término dos preparos foi feita a moldagem utilizan­do-se a técnica da dupla moldagem e confecção da restauração provisória envolvendo os três elementos com resina acrílica. Na segunda sessão, a peça protética foi cimentada, a oclusão verificada e ajustada. Uma vez que os cerômeros têm resistência de união boa e semelhante à das cerâmicas, além de apresentarem caraterísticas mecânicas muito semelhantes à estrutura dental, conseguem atuar de forma satisfatória na distribuição das cargas oclusais em dentes posteriores. Assim, pode-se concluir que as restaurações livres de metal são ótimas alternativas para proporcionar a paciente uma melhora estética e funcional, além de integridade das margens e do periodonto, estabilidade estrutural, retenção e resistência da restauração.

Background/Aims Traumatic dental injuries are highly prevalent and are considered an important health problem. The aim of this study was to evaluate the in vitro stress distribution around simulated traumatized teeth subjected to different types of splints by photoelastic analysis. Materials and Methods For each group, five models of maxillary and mandibular arches were made in photoelastic resin using prefabricated teeth models, which were fixed and adjusted in a semi‐adjustable articulator. All splints were bonded with composite resin on the labial surfaces of the maxillary central incisors, the lateral incisors and the canine teeth, simulating trauma to the 11. The groups were divided according to the type of splint: control—without splint; rigid—brackets and 0.021 × 0.025 inch stainless steel wire; semi‐rigid—brackets and 0.016 × 0.016 inch cobalt‐chromium wire; fiber—fiberglass ribbon; and flexible—nylon thread. The groups were submitted to an occlusal force in a special device attached to a universal test machine in balanced, protrusive, and lateral occlusions. Then, the incisal edge of the 11 was ground to simulate infra‐occlusion, and the tests were performed again. Five points were analyzed around tooth 11 with a polariscope, and the data were submitted to ANOVA and Tukey tests at a 5% level of significance. Results When centric occlusion was analyzed by comparing normal occlusion to infra‐occlusion, all groups showed high stress values in infra‐occlusion with statistical differences—except for the control group. When lateral occlusion was analyzed, the nylon splint showed lower statistical differences compared with the control, fiberglass, and rigid splint groups, which did not differ between each other. The semi‐rigid splint did not differ from any group. Conclusions Fiberglass and semi‐rigid splints showed better stress distribution around the traumatized tooth under occlusal loads. The nylon splint showed characteristics of non‐stress distribution.