Efeito da temperatura de trabalho do cimento odontológico resinoso na propriedade de viscosidade do material

Abstract

Resin cements are the most commonly used materials for indirect restoration fixation and can be classified as conventional or self-adhesive. Preheating resin-based composites can reduce their viscosity and improve marginal adaptation. This study aimed to investigate the effect of preheating on the viscosity of two resin cements, one conventional and the other self-adhesive, varying the working temperature (room temperature - 23°C and preheated - 69°C). The analyses were performed in accordance with specification no. 08 of the American Dental Association (ADA). The materials were dispensed onto a glass plate and subjected to a compression load of 150 N (±2 N) applied for a period of 180 s (±10) using a universal testing machine (n=5). The diameter of the circumference formed by the cement on the plate, in millimeters (mm), was measured using a digital caliper. The circumference area was calculated (A=𝝅r2) and the viscosity was determined by the different areas obtained, with the material with the smallest area being considered to have the lowest viscosity. The data obtained were analyzed using two-way ANOVA and Tukey tests (α=5%). It was found that conventional cement showed a significant reduction in viscosity after preheating (p<0.05), which was not observed for self-adhesive cement. These findings suggest that preheating may be an effective strategy to optimize the use of conventional resin cements, potentially improving the clinical success of dental procedures.