From names to concepts: Unraveling bioactivity in restorative dental materials

The authors aimed to establish the scope and types of evidence concerning the bioactivity of materials used in restorative dentistry. The investigation adhered to the Preferred Reporting Items for Systematic reviews and Meta-Analyses Extension for Scoping Reviews and Joanna Briggs Institute methodologies for scoping reviews and was registered on the Open Science Framework platform.

A systematic search was conducted across PubMed/MEDLINE, Embase, Scopus, and Web of Science databases through May 31, 2024, along with gray literature and manual searching of the list of references in the articles. Inclusion criteria encompassed clinical and laboratory studies exploring the bioactivity of restorative materials, including both temporary and permanent, commercially available, or experimental materials. Studies deviating from manufacturer's suggested applications for the materials were excluded.

The qualitative analysis incorporated 80 studies. There was a predominance of in vitro studies (63), complemented by a smaller number of reviews (11), randomized clinical trials (4), and case reports (2). Among the various types of restorative materials, resin composites and resin cements were investigated most extensively. Additive components commonly used within the studied restorative materials were bioactive glass and hydroxyapatite or nanohydroxyapatite.

Clinically, the benefits of composites purported to be bioactive remain uncertain. This is largely because the scientific evidence for the bioactivity of dental restorative materials comes mainly from in vitro studies, and there is an absence of specific guidelines for the use of these materials. At this stage, using complementary in vitro methods, such as assessing apatite formation, therapeutic ion release, and mineral formation at the dentin-material interface, is recommended to evaluate bioactivity.