Comparing the Effect of Polymerization Shrinkage Between Bulk-Fill and Conventional Composite: A Systematic Review

Abstract

Introduction:
A bulk-fill composite is a newly introduced resin-based material. It is considered an improvement in the resin-based restorations. Published literature about their physical and mechanical properties yield inconsistent or sometimes contradicting results. Therefore, an in-depth review of this literature could be a helpful guide for dentists to use these new promising restorative materials. This review aimed to provide an evidence-based comparison between bulk-fill and conventional composite.
Methods:
We searched electronic databases for articles, published in English language, that compare polymerization shrinkage between bulk-fill and conventional composite. Databases of PubMed and Embase were searched for clinical trials or cohort studies. The exclusion of the irrelevant studies based on the full text of articles was done to include finally 7 studies.
Results:
The polymerization shrinkage and stress of flowable bulk fill composite was assessed by 7 studies, and there was no large variation between the findings of these studies. The mean percentage of polymerization shrinkage in flowable bulk-fill composite was found to range from 2.8 to 4.40, while the mean percentage of polymerization shrinkage in paste-like bulk-fill composite was found to range from 0.9 to 2.6. Like flowable counterparts, all studies found that polymerization stress of paste-like bulk-fill composite to be lower than that of the conventional composite.
Conclusion:
Based on the available literature, there is no substantial difference in the polymerization shrinkage between bulk fill composite and conventional composite.