polymers Review The Photoinitiators Used in Resin Based Dental Composite—A Review and Future Perspectives Andrea Kowalska , Jerzy Sokolowski and Kinga Bociong * Department of General Dentistry, Medical University of Lodz, 92-213 Lodz, Poland;
[email protected] (A.K.);
[email protected] (J.S.) * Correspondence:
[email protected] Abstract: The presented paper concerns current knowledge of commercial and alternative photoini- tiator systems used in dentistry. It discusses alternative and commercial photoinitiators and focuses on mechanisms of polymerization process, in vitro measurement methods and factors influencing the degree of conversion and hardness of dental resins. PubMed, Academia.edu, Google Scholar, Elsevier, ResearchGate and Mendeley, analysis from 1985 to 2020 were searched electronically with appropriate keywords. Over 60 articles were chosen based on relevance to this review. Dental light-cured composites are the most common filling used in dentistry, but every photoinitiator system requires proper light-curing system with suitable spectrum of light. Alternation of photoinitiator might cause changing the values of biomechanical properties such as: degree of conversion, hardness, biocompatibility. This review contains comparison of biomechanical properties of dental composites including different photosensitizers among other: camphorquinone, phenanthrenequinone, ben- zophenone and 1-phenyl-1,2 propanedione, trimethylbenzoyl-diphenylphosphine oxide, benzoyl peroxide. The major aim of this