The use of bioactive glass (BAG) in dental composites: A critical review

In recent years, numerous studies have analyzed the role of bioactive glass (BAG) as remineralizing additives in dental restorative composites. This current review provides a critical analysis of the existing literature, particularly focusing on BAGs prepared via the melt-quench route that form an "apatite-like" phase when immersed in physiological-like solutions.

Online databases (Science Direct, PubMed and Google Scholar) were used to collect data published from 1962 to 2020. The research papers were analyzed and the relevant papers were selected for this review. Sol-gel BAGs were not included in this review since it is not a cost-effective manufacturing technique that can be upscaled and is difficult to incorporate fluoride.

BAGs release Ca²⁺, PO₄^3- and F^- ions, raise the pH and form apatite. There are numerous published papers on the bioactivity of BAGs, but the different glass compositions, volume fractions, particle sizes, immersion media, time points, and the characterization techniques used, make comparison difficult. Several papers only use certain characterization techniques that do not provide a full picture of the behavior of the glass. It was noted that in most studies, mechanical properties were measured on dry samples, which does not replicate the conditions in the oral environment. Therefore, it is recommended that samples should be immersed for longer time periods in physiological solutions to mimic clinical environments.

BAGs present major benefits in dentistry, especially their capacity to form apatite, which could potentially fill any marginal gaps produced due to polymerization shrinkage.