Evaluation and Comparison of Shear Bond Strength of Composite to Silver Diamine Fluoride & Air Abrasion Treated Dentin: An In-vitro Study

Abstract

Background: Silver diamine fluoride (SDF) effectively arrests dental caries by forming a silver-protein complex and calcium fluoride deposits, preventing bacterial activity and remineralizing dentin. However, SDF application adversely affects bond strength when composite restoration is performed immediately due to a hyper mineralized layer that inhibits resin infiltration. Objectives: This study aimed to evaluate and compare the shear bond strength (SBS) of composite resin to SDF-treated dentin under different conditions, including immediate and delayed bonding after SDF application (2 and 15 days), with and without air abrasion. Materials and Methods: An in-vitro study was conducted on 54 extracted human teeth sectioned to expose mid-coronal dentin. The specimens were treated with 38% SDF and divided into six groups (n=9) based on bonding time and surface treatment: no air abrasion, with air abrasion, SDF with immediate restoration with/without air abrasion, and SDF with delayed restoration with/without air abrasion. Composite resin was bonded using an eighth-generation bonding agent. SBS was tested using a universal testing machine, and failure modes were evaluated under a stereomicroscope. Kruskal-Wallis and Mann-Whitney U tests were used for group comparisons. A p-value <0.05 was considered statistically significant Results: SBS was highest in the SDF 15 days with air abrasion group (mean = 20.62 MPa, p < 0.001). Air abrasion significantly improved SBS, while SDF 15 days without air abrasion showed the lowest SBS (mean = 3.18 MPa). Mixed failure was the most common failure mode across all groups. Conclusion: Delaying bonding after SDF application, particularly for 15 days combined with air abrasion, significantly improves SBS. The use of an eighth-generation bonding agent further enhances adhesive outcomes in SDF-treated dentin.