Evaluation of Tensile Bond Strength of Metallic Prefabricated Posts Cemented with Different Luting Agents

Abstract Objective: To assess the tensile bond strength of prefabricated metal posts cemented with different luting agents. Material and Methods: Fifty single-rooted endodontically treated human teeth had their crowns cut, mounted into acrylic-resin blocks and then an 8mm depth post space were prepared. Prefabricated cylindrical metal posts were cemented using different luting agents: a zinc phosphate cement (SS White), a conventional glass ionomer cement (Vidrion C), two resin-modified glass ionomer cements (Vitremer and RelyX Luting 2) and a resin cement (RelyX ARC). Samples were stored in distilled water for seven days and then submitted to a tensile bond strength test until complete dislocation of the post. One-way analysis of variance and Tukey test for pairwise multiple comparisons were used to evaluate differences between luting agents. Results: Tensile bond strength was 563.88±203.41 N for zinc phosphate cement, 336.86 ± 137.64 N for Vidrion C, 515.24 ± 239.48 N for Vitremer, 828.47±433.99 N for RelyX Luting 2 and 1262.51 ± 356.29 for RelyX ARC. The Relyx ARC presented the highest tensile bond strength regard the luting agent tested (p< 0.05). Conclusion: RelyX ARC presented the higher tensile bond strength compared to the other luting agents evaluated.

Estabilidade de cor de cerâmica odontológica após glaze e polimento / Color stability of dental ceramics after glaze and polishing

Objetivo: Avaliar a influência de soluções corantes, em diferentes períodos de imersão, na estabilidade de cor de uma cerâmica odontológica em função de diferentes tratamentos de superfície (Glaze e Polimento). Material e Métodos: dezoito amostras de cerâmica foram fabricadas de acordo com as recomendações do fabricante. As amostras foram randomicamente divididas em dois grupos de acordo com o tratamento superficial realizado: Grupo Glaze (controle): glazeadas; Grupo Polimento: amostras polidas com pontas para polimento e pasta diamantada para polimento. Após, três amostras de cada grupo foram imersas em café, vinho tinto ou água por trinta dias. A mensuração de cor foi realizada através de fotografias digitais antes da imersão, após sete, quinze e trinta dias. Os valores de RGB foram obtidos utilizando o programa Adobe Photoshop e convertidos para valores Lab. Teste T de Student, ANOVA e teste Tukey foram utilizados para a análise estatística (p ≤ 0.05). Resultados: os maiores valores de alteração de cor foram proporcionados pelo vinho tinto no grupo glaze (p < 0.05), o grupo glaze e polimento não apresentaram valores de alteração de cor estatisticamente significativos em todas as soluções avaliadas (p > 0.05), as amostras apresentaram estabilidade de cor após 15 dias de imersão nas soluções. Conclusão: o polimento realizado se mostrou tão eficiente quanto o glaze.(AU)

Aim: To evaluate the influence of staining diet solutions at different periods of immersion in the color stability of dental ceramics submitted to different surface treatments (glaze and polishing). Methods: Eighteen samples of ceramics were manufactured according to the manufacturer's recommendations. The samples were randomly divided into two groups according to the surface treatment conducted: Glaze group (control): glazed; Polishing Group: polished samples with tips for polishing and diamond paste forpolishing. After, three samples from each group were immersed in coffee, red wine, or water for thirty days. The measurement was performed using color digital photographs before immersion and after seven, fifteen, and thirty days. The RGB values were obtained using the Adobe Photoshop program and converted to Lab. Student's t test. ANOVA and Tukey test values were used for statistical analysis (p ≤ 0.05). Results: The highest values of color change were provided by red wine in the glaze group (p < 0.05); the polishing and glaze groups showed no statistically significant values of change in color in all of the evaluated solutions (p > 0.05); samples presented color stability after 15 days of immersion in solutions. Conclusion: The polishing performed in this study proved as efficient as the glaze.(AU)