This study evaluated the immediate and 6-month dentin bond strength of universal adhesives used in etch-and-rinse or self-etch bonding strategies. The adhesives tested were Ambar Universal, G-Bond, Single Bond Universal, Tetric N-Bond Universal, and Ybond Universal. Gold standard adhesives (Scotchbond Multipurpose Plus and Clearfil SE Bond) were controls. Microtensile dentin bond strength (n=5 teeth), pH, and C=C conversion (n=3) were evaluated. Data were analyzed at α=0.05. All adhesives showed differences in pH. Ybond had intermediately strong aggressiveness, whereas the others were ultra-mild. The C=C conversion was different in most adhesives. In the etch-and-rinse strategy, all adhesives showed similar results generally except for G-Bond, which had lower bond strength than most adhesives. G-Bond and Tetric-N-Bond showed lower bond strengths after 6 months compared with 24 h, whereas the other adhesives had stable dentin bonds. In the self-etch strategy, G-Bond had lower bond strength than most adhesives. After 6 months, Ambar was the only adhesive showing lower dentin bond strength compared with 24 h. Most adhesives had discreet drops in bond strength during aging when used in the self-etch strategy. The failure modes were also material dependent, with a general pattern of increased adhesive and/or pre-testing failures after storage. In conclusion, the bonding performance of universal adhesives to dentin is material dependent. Most adhesives had stable dentin bonds with results comparable to the gold standard materials, particularly when applied in the self-etch mode. In general, it seems the use of universal adhesives in dentin should not be preceded by phosphoric acid etching.

chemical cleaning agents and bonding to glass-fiber posts abstract: The influence of chemical cleaning agents on the bond strength between resin cement and glass-fiber posts was investigated. The treatments included 10% hydrofluoric acid, 35% phosphoric acid, 50% hydrogen peroxide, acetone, dichloromethane, ethanol, isopropanol, and tetrahydrofuran. Flat glass-fiber epoxy substrates were exposed to the cleaners for 60 s. Resin cement cylinders were formed on the surfaces and tested in shear. All treatments provided increased bond strength compared to untreated control specimens. All failures were interfacial. Although all agents improved the bond strength, dichloromethane and isopropanol were particularly effective.

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The aim of this study was to assess the effect of endodontic chemical substances on the retention of fiber posts luted using a self-adhesive cement. Single-canal human roots of 75 teeth were divided into 5 groups (n = 15). Root canals were instrumented with one of the following substances: 0.9% NaCl (control); 5.25% sodium hypochlorite; 5.25% Sodium hypochlorite + 17% EDTA; 2% chlorhexidine gel; 2% chlorhexidine gel + 17% EDTA. After chemo-mechanical preparation, fiber post cementation was performed with self-adhesive resin cement (RelyX Unicem, 3 M/ESPE). One-way ANOVA was performed followed by a multiple comparison Tukey post hoc test (α = 5%). The use of 2% chlorhexidine gel resulted bond strength statistically similar to the control group (p = 0.418), which was higher than the other groups. A final irrigation with 17% EDTA significantly reduced bond strength (p < 0.001). The use of 5.25% sodium hypochlorite negatively affected the bond strength, either with or without a final irrigation with 17% EDTA (p < 0.001). Our results suggest that 2% chlorhexidine gel used during endodontic chemo-mechanical preparation, without a final irrigation with 17% EDTA, promotes a more favorable condition to the retention of fiber posts luted using a self-adhesive cement than 5.25% sodium hypochlorite.

Tooth fragment reattachment in cases of enamel/dentin fracture is based on adhesive protocols and is indicated because of its technique simplicity. Complex cases of root fracture or extensive coronal damage demand the integration of biological properties with the mechanical characteristics of the restorative materials. This paper is a report from one patient with a favourable result that addresses the clinical procedures involved in the association of resin-modified glass ionomer cement and composite resin for cases of coronal fracture of anterior teeth with invasion of the periodontal biological space and/or proximity with the pulp tissue. The research-based background for establishment of the treatment plan is discussed and a case of crown fracture with root involvement in a maxillary central incisor illustrates the operative technique of tooth fragment reattachment. After 1 year of follow up, the clinical and radiographic findings demonstrate that the adopted clinical protocol was successful and yielded an excellent pulp and periodontal response as well as maintenance of function and aesthetics.

Em função da atual exigência estética por parte dos pacientes e profissionais, novos materiais e técnicas têm sido desenvolvidos para que o resultado final das restaurações seja cada vez mais semelhante ao dente natural. Dentro deste contexto, a translucidez é uma das características mais difíceis de serem reproduzidas pelos materiais restauradores estéticos diretos. Por ser uma propriedade característica do esmalte encontram-se hoje no mercado resinas compostas específicas para a substituição desta estrutura. Assim, este trabalho tem como objetivo estudar comparativamente os diferentes níveis de translucidez das resinas compostas A110 e Durafill (A1, A2 e A3) e Vitalescence (TM, TY, TI, TS, TA, TG), com a translucidez de corpos-de-prova de esmalte. Pôde-se observar que todas as cores da resina composta Vitalescence apresentaram valores de translucidez muito acima dos valores encontrados para o esmalte e para as demais resinas, enquanto que as resinas compostas A110 e Durafill apresentaram valores estatisticamente semelhantes entre si e ao esmalte, com exceção para a cor A1 da resina Durafill, que se apresentou ligeiramente menos translúcida.

Os cimentos de ionômero de vidro apresentaram uma diminuição em seu uso clínico como conseqüência de sua limitação estética e mecânica em relação às resinas compostas. Porém, devido à intensa discussão sobre a efetiva biocompatibilidade e resistência de união a longo prazo dos sistemas adesivos, tem-se intensificado novamente o interesse pelos cimentos ionoméricos. Em relação à resistência de união, apesar dos valores imediatos apresentados pelos sistemas adesivos serem mais elevados que os de cimentos de ionômero de vidro, estes tendem a diminuir significativamente quando avaliados a longo prazo, enquanto a resistência dos cimentos de ionômero de vidro se mantém. Por este motivo, alguns autores têm classificado este cimento como um agente de união. Quanto à sua biocompatibilidade, os trabalhos mais recentes demonstram a possibilidade de sua utilização como substituto dos cimentos de hidróxido de cálcio para proteção pulpar indireta e como material restaurador em locais de íntima relação com tecidos periodontais, em função da boa tolerância destes aos cimentos de ionômero de vidro.

AIM: The aim of this study was to evaluate two composite restorations (conventional methacrylate-based and low shrinkage-based silorane), associated or not to beveling and incremental technique, in relation to the microleakage and marginal gap formation tests. MATERIAL AND METHODS: 30 sound human molars had their mesial and distal surfaces prepared with and without bevel. The teeth were divided into six groups according to the type of resin (conventional nanofilled or silorane resin), and restorative filling technique (incremental technique or builk). Microleakage and marginal gap formation data were statistically analyzed by Kruskal-Wallis and Chi-Square tests, with a significance level set at 5%. RESULTS: Group 1 (Z350 XT, without bevel, incremental technique) presented highest rate of microleakage and marginal gap in most of the restorations, with statistically significant differences. Groups 4 and 6 (P90, beveled, builk and P90, beveled and incremental technique) had lower rates of microleakage and absence of marginal gaps in most of the restorations. CONCLUSION: It’s concluded that the silorane showed lower rates of marginal gaps and microleakage, when compared to the conventional methacrylate-based resin. Bevel preparation was effective in reducing microleakage and marginal gaps for both resins used. Incremental technique was not necessary when associated with low shrinkage composite resin.