Effect of silver diamine fluoride on the longevity of the bonding properties to caries-affected dentine

Objectives: This study aimed to evaluate the adhesive properties in dentine after the application of silver diamine fluoride (SDF) on carious dentine lesions immediately and after 2 years of water storage. Methods: 96 human molars used were subjected to artificial dentine caries production, and then randomly divided into 12 experimental groups according to 1. application of an SDF solution (carious dentine lesion without SDF treatment [control], with 12 % silver diamine fluoride [SDF 12 %] or 38 % silver diamine fluoride [SDF 38 %]); 2. Universal adhesives (Clearfil Universal Bond Quick [CUQ] and Single Bond Universal [SBU]); 3. adhesive strategy (etch-and-rinse [ER] and self-etch [SE]). After restoration, the specimens were sectioned and submitted to the microtensile bond strength test (mu TBS) and energy-dispersive X-ray spectrometry analysis (SEM/ EDX). All tests were performed immediately and after 2 years of water storage. Data from the mu TBS were analyzed using four-way ANOVA and Tukey's test (alpha = 0.05). Results: Only the interaction of factors 'SDF' vs 'time' was significant (p = 0.03). After 2 years of storage, the groups where SDF was applied showed higher mu TBS values compared to the control group. No significant decrease in mu TBS values was observed for SBU when comparing immediate and 2-year results, but a significant reduction in mu TBS values was observed after 2 years for CUQ. Conclusion: Independent of the adhesive strategy, the use of SDF may be a promising alternative to maintain the bonding of universal adhesives to carious dentinal lesions. Clinical significance: This study may clarify and support clinicians regarding the longevity of resin-based restoration in caries-affected dentine treated with silver diamine fluoride.