Micro-coMputed toMographic assessMent of the influence of light-curing Modes on internal void forMation in bulk-fill coMposites

Abstract

Introduction: Polymerization reactions in a new generation bulk-fill composites carried out in a short time with high irradiation, raise concerns about curing processes. With micro-computed tomographic evaluation, it is possible to investigate polymerization shrinkage, and subsequent gap and void formation in dental materials. Objectives: The aim of this study was to evaluate the void formation in bulk-fill composites light-cured with different modes using micro-computed tomography. Material and methods: Class I preparations were made in 25 molars that were randomly divided into subgroups, according to resin composite and curing mode used: Tetric EvoCeram (TEC)*high power mode, TEC*turbo mode, Tetric PowerFill (TPF)*high power mode, TPF*turbo mode, and TPF*3s mode. Each tooth was scanned at two time intervals: pre- and post-cure. Results: After light-curing, a significant increase in the total volume of internal void was noted for both composites cured with high power mode compared with pre-cure. The difference between the sub-groups at post-cure was also significant. While TEC exhibited similar values in terms of different curing modes, turbo and 3s modes caused a significant difference in TPF group, and the lowest void percentage was detected in 3s mode. Conclusions: Internal void formation results from an interplay of different factors, including composition of materials and curing modes. © 2024 Polish Dental Association.