Prevention of secondary caries by silver diamine fluoride

Objectives: To investigate the use of 38% SDF as a conditioner for the prevention of secondary caries in glass ionomer cement (GIC) and composite resin (CR) restoration.
Methods: Six extracted sound human premolars were collected. Four cavities (4×2×2 mm³) were prepared on each premolar and then allocated to the following restoration groups: Group 1 SDF conditioning and GIC restoration; Group 2 GIC restoration; Group 3 SDF conditioning and CR restoration; and Group 4 CR restoration. After thermal cycling and sterilisation, the teeth were soaked in a cariogenic environment for 28 days. Microcomputed tomography was used to study the demineralisation. The outer lesion depth (OLD) and wall lesion depth (WLD) of the tooth-restoration interface were measured. Two-way ANOVA was used to analyse the effects of SDF conditioning and restorative materials on OLD.
Results: The OLD (mean ± SD µm) in Groups 1 through 4 were 272 ± 56, 153 ± 59, 212 ± 40, and 177 ± 51, respectively. There was no significant difference in OLD between GIC or CR restorations (p = 0.684), but OLD was less in restorations with SDF conditioning (p = 0.004). No interaction effect on OLD was found between the restorative materials and SDF conditioning (p = 0.062). The WLD was detected only in Groups 3 and 4.
Conclusions: Conditioning with 38% SDF can increase resistance of GIC and CR restorations to secondary caries.
This study was supported by HKU Small Project Funding (No. 201309176058).