Enhancing antimicrobial, physical, and mechanical properties of restorative dental materials through metallic nanoparticle incorporation: a systematic review and meta-analysis

Background This systematic review with meta-analysis aimed to evaluate if the incorporation of metallic nanoparticles (NPs) in dental materials present antimicrobial effects without prejudice to physical and mechanical properties. Material and methods After PROSPERO registration (CRD42022297684), Medline via Pubmed, Scopus, Web of Science, EBSCO, LILACS, LIVIO, Embase and grey literature such as Google Scholar, ProQuest and OpenGrey, were searched until June 26th, 2024. Meta-analysis of materials incorporated with metallic nanoparticles was performed for antimicrobial action (standardized mean differences) and mechanical properties (mean differences) through inverse variance and randomized effects (Revman, p < 0.05). Results For risk of bias, studies were evaluated according to the Joanna Briggs Institute's critical assessment. Forty-four out of the 3818 articles initially identified were eligible for the review, and 30 were included in the meta-analysis. Meta-analysis pointed out that the incorporation of silver and copper presented antimicrobial activity, reducing colony forming units (CFU) when incorporated in primer and glass ionomer cement (GIC). Silver increased inhibition zones and reduced cell viability through live dead cell viability assay in primer, GIC and adhesives. Silver incorporation reduced microhardness and shear strength of adhesives and increased compressive strength of GIC and shear strength of primer. Conclusions The incorporation of metallic nanoparticles, especially silver copper and titanium presented benefits to antimicrobial properties compared with the original unmodified materials. However, some mechanical properties of restorative dental materials were damaged. In contrast to some studies in the literature that evaluated metallic nanoparticles, our findings indicate negative effects on properties.