Photoactivation systems and their impacts on resources in compound resin: a literature review

Abstract

Photoinitiating substances and photoactivation devices are directly conected to the physical-mechanical and chemical performance of the composite resins. Due to the yellowish coloration from camphorquinone (CQ), alternative photoinitiators have been used in a complementary or substitute way. Thus, the objective of the study was to develop a literature review on photoinitiators in correlation with photoactivation and its impacts on composite resin restorations. The literature review has been conducted based on researches in the Scielo, PubMed and Google Scholar databases through the descriptors: composite resins, polymerization and photoinitiators. In the search carried out between March and June 2020, of the forty-two articles found, thirty-seven articles were used. Among the variations of the photoinitiator systems, it's been observed that in general, they presented positive points such as good physical-mechanical and chemical performance with the evaluation of the degree of conversion, flexural strength and microhardness. They also presented negative points such as high toxicity, gap formation and unsatisfactory indices of microleakage in dentin. In relation to photoactivation systems, light emitting diodes (LEDs), called polywave, brought advantages by emitting a larger wave spectrum that reaches the violet color, necessary to activate the polymerization chemical reaction of the alternative photoinitiators. It can be concluded that the emergence of new photoinitiating substances and polywave devices establish a certain harmony with the light supply capacity, the reaction of the substances and the reach of the physical-mechanical properties provided by them.