Properties of Resins Used in Implant-Supported Provisional Complete Dentures

Objectives: This study aimed to evaluate the microhardness, roughness, and flexural strength of thermopolimerizable resins used in implant-supported fixed provisional complete dentures with and without internal metallic reinforcement, before and after accelerated aging.
Methods: Ninety samples were fabricated and divided in 3 groups: Group 1: VIPI Cril Plus resin with metallic reinforcement (control); Group 2: VIPI Cril Plus resin without metallic reinforcement; Group 3: Diamond D resin without metallic reinforcement. Microdardness analysis was carried out by means of a microdurometer; roughness analysis, by means of a profilometer; and flexural strength analysis, by the 3-point flexion test. The aging of samples was carried out in a thermocycler with immersion in distilled water in alternating baths of 30 seconds at temperatures of 5 ± 1^oC and 55 ± 1^oC, with a total of 500 cycles. The data were subjected to Analysis of Variance, followed by the Tukey test with a significance level of 5%.
Results: In the initial and final periods, the Group 3 presented significantly lower microhardness than the other groups. There was an increase in microhardness in the Group 2 with aging. The Group 3 showed significantly higher roughness than the Group 2 in the initial period, and then the other 2 groups in the final period. There was an increase in roughness in Groups 2 and 3 with aging. The Group 3 resin did not fracture when subjected to flexural resistance analysis, showing a deflection greater than 5 mm.
Conclusions: Although the Diamond D is a flexible resin, it presented lower microhardness and greater roughness than the other groups. The accelerated aging negatively interfered with the resins’ properties.