Controversies about refrigeration of dental adhesives: a review

Abstract

INTRODUCTION: The refrigeration of dental adhesives is a routine practice, often adopted without thorough understanding or consideration of its scientific basis and potential clinical consequences. This review explores the effects of refrigeration and subsequent immediate use on the bonding effectiveness of dental adhesive systems. Given the ongoing debate in the literature about how storage temperature influences adhesive characteristics such as viscosity, degree of conversion, and bond strength, this work synthesizes findings from both supportive and contradictory studies to inform clearer clinical guidance. METHODS: Relevant literature was identified through a comprehensive search of key databases, including PubMed, Scopus, and Google Scholar, focusing primarily on in-vitro studies that investigated the effect of refrigeration on the bond strength and bonding-related kinetics of various adhesive systems: etch-and-rinse, self-etch, and universal adhesives. RESULTS: The collected data suggest that immediate use of adhesives post-refrigeration may induce material-dependent adverse changes in viscosity, solvent evaporation, and polymerization kinetics. These changes have primarily been linked to various factors that appear to critically mediate the influence of low temperature, including adhesive composition and solvent type. Although some studies have supported these findings, the anticipated deleterious effects could not be definitively confirmed, as several other investigations have reported negligible or no effects at all across different adhesive systems. CONCLUSIONS: The heterogeneity of findings indicates that no conclusive agreement has been established regarding the actual risks associated with refrigerating dental adhesives. Nonetheless, the absence of evidence supporting any benefit from immediate post-refrigeration use suggests that allowing adhesives to reach room temperature before use remains a cautious and prudent approach.