Effects of cross-linking agents and radiopacifying fillers on degree of conversion and volumetric shrinkage of denture based methacrylic resins

Abstract

"Development of experimental dental prostheses formulations based on methacrylic resins. The effect Study, on the degree of conversion (DC) and volumetric shrinkage (VS), of four crosslinking agents: DEDGMA, TEGDMA, TETRAEGDA and TMPTA and four radiopacifying mineral fillers: ZrO2, TiO2, SrO and BaO2. The experimental resins are compared to commercial products. The (DC) determination of the experimental and commercial resins was carried out by FTIR in ATR mode. The (VS) was determined experimentally by the Archimed’s method. Chemical structure and weight content of crosslinking agents affected (DC) and (VS). (DC) and (VS) increased with the crosslinking agent chain length and weight contents. Additionally, whatever filler contents and metal nature, (DC) values remains ≥ 99.5%, in accordance with the standards required for residual monomers level tolerated in dental prostheses (<0.45%). (VS) values varied between 4,8 and 10,8%. For two commercial resins, (DC) values were less than 99% while (VS) was in accordance with the standards (5-6%): 6.2% for Major base and 4.3% for Hiflex H."