The role of oral environmental factors in the degradation of resin-dentin interfaces: A comprehensive review.

OBJECTIVES

Despite the considerable benefits of using resin composites for dental defect restoration, the resin-dentin interface remains highly vulnerable to contamination within the complex oral microenvironment. This article reviews the causes, contributing factors, and preventive measures affecting resin-dentin bonding.

DATA: Data were collected using the following keywords: bond strength, resin, dentin, saliva, bacteria, blood, contamination, smear layer, hybrid layer, fluorination, and antibacterial ingredients.

SOURCES: An electronic search was conducted using PubMed and Web of Science databases. Bibliographic references from the reviewed papers were then used to identify additional relevant publications.

CONCLUSION

Salivary esterases break down ester linkages in resin monomers, resulting in monomer leaching and subsequent polymer degradation. Bacterial activity exacerbates this interfacial breakdown through enzymatic processes and acid production, thereby accelerating adhesive failure. Blood contamination further compromises resin-dentin bonding by forming protein-rich barriers that hinder adhesive penetration. Additionally, we systematically summarise evidence-based strategies to enhance bond strength, including-but not limited to-the incorporation of fluoride compounds and antibacterial monomers.

CLINICAL SIGNIFICANCE: This review offers a comprehensive overview of the various contaminants in the oral microenvironment that may compromise the resin-dentin interface, either directly or indirectly. It also highlights actionable strategies for improving adhesive performance, thereby serving as a valuable reference for clinicians and researchers aiming to optimise restorative outcomes.