Influence of light energy density, composite type, composite thickness, and postcuring phase on degree of conversion of bulk-fill composites

Abstract

CONTEXT: Achieving a high degree of conversion (DC) is one of the major concerns during photopolymerization of bulk-fill composites. AIMS: ) on the DC and variation of DC in the 24-h postcuring of four bulk-fill composites: SDR, Venus Bulk Fill, MI FIL, and Tetric N-Ceram Bulk Fill at simulated clinically relevant filling depths. SETTINGS AND DESIGN: comparative study. SUBJECTS AND METHODS: ) applied during a certain time (s) divided by 1000. The DC was measured at two time intervals: immediately postcure and after 24-h storage in artificial saliva using an Fourier-transform infrared spectroscopy equipped with attenuated total reflectance accessory. STATISTICAL ANALYSIS USED: < 0.05. RESULTS: < 0.005) than those of their bottom surface. Among composites, SDR showed highest DC. DC strongly increased after 24-h postcure by 32% on top surface and 76% on bottom surface. CONCLUSIONS: , derived by increasing curing time and low power density, helps obtain a high DC of bulk-fill composites for adequate clinical performance.