Effects and Properties of Deproteinizing Methods in Dentin: A Comprehensive Narrative Review

Dentin deproteinization strategies are being revisited as adjunctive approaches to reduce technique sensitivity, improve monomer infiltration to mineralized dentin, and enhance the longevity of resin-dentin interfaces. This organized narrative review critically summarizes the chemistry, kinetics, biological considerations, and clinical translatability of agents used for smear-layer deproteinization or post-etching deproteinization. Searches of PubMed/MEDLINE, Scopus, and LILACS up to October 2025 were used to identify evidence on oxidizing irrigants (sodium hypochlorite/hypochlorous acid, calcium hypochlorite, peracetic acid, chlorine dioxide), enzymatic proteolysis treatments (bromelain, papain, trypsin/pepsin, and GAG-targeting enzymes), physical approaches (heat and lasers), and post-oxidizer reducing/antioxidant strategies. Oxidizers provide the fastest and most surface-verified organic removal, but their clinical value is limited by concentration- and time-dependent oxidative carry-over, which interferes with free-radical polymerization. Enzymes offer a more selective route, although their support is driven largely by bond strength and morphological outcomes rather than direct surface-chemical confirmation. Heat remains a proof-of-principle method rather than a clinical option, whereas laser protocols are highly parameter-sensitive. Overall, deproteinization should be interpreted through a combined framework of surface chemistry, adhesive compatibility, aging behavior, biosafety, and chairside feasibility. Current evidence supports cautious, protocol-specific development rather than routine clinical adoption, with priority given to clinically realistic time-dose windows and paired surface/aging outcomes.