Biocompatibility of Pit and Fissure Sealants: Scoping Review of In Vitro and In Vivo Evidence

Objectives: This scoping review summarized the evidence on the biocompatibility of pit and fissure sealants, focusing on cytotoxicity, genotoxicity, and overall biological safety of commercial and experimental materials evaluated in vitro and in vivo. Methods: Following the PRISMA-ScR guidelines, eligibility was defined using the Population, Concept, and Context (PCC) framework: the population comprised cell cultures, animal models, or human participants exposed to sealants; the concept was biocompatibility, including cytotoxicity, genotoxicity, and inflammatory or tissue response; and the context encompassed commercial and experimental pit and fissure sealants used in preventive dentistry, particularly in pediatric populations. PubMed and Scopus platforms were searched without restrictions on publication year or language. Studies assessing biocompatibility (cytotoxicity, genotoxicity, inflammatory or tissue response) in cell cultures, animal models, or humans were eligible; those evaluating only clinical efficacy were excluded. Two reviewers independently performed study selection and data extraction. Results: Of 406 records (291 after deduplication), 10 studies were included—nine in vitro and one in vivo. Resin-based sealants predominated, mainly assessing residual monomers (TEGDMA, Bis-GMA) and their effects on fibroblasts, keratinocytes, periodontal ligament cells, and buccal epithelial cells. TEGDMA was released most frequently, whereas Bis-GMA showed the highest cytotoxicity. Experimental sealants containing nano-calcium fluoride, calcium phosphate, bioactive glass, or antibacterial monomers generally showed favorable biocompatibility, although high additive concentrations reduced cell viability. The single in vivo study reported good biocompatibility without significant genotoxicity. Conclusions: Pit and fissure sealants generally show acceptable biocompatibility and remain safe for caries prevention, although the biological response depends on composition, degree of polymerization, and residual monomer release. Further standardized long-term in vivo research is needed, particularly in pediatric populations.