Method: AgNPs were generated in situ in UltraSeal XT® Hydro™ (Ultradent Products, Inc.) pit and fissure resin sealant using different concentrations of silver benzoate (AgBz; 0.01 to 0.5 wt%) and BOC (0.05 to 10 wt%). Controls included UltraSeal XT® Hydro™ and the same sealant formulated in house (UTSeal). Sealants were light-cured and tested with Rockwell15T hardness to determine degree of cure, three-point bending to determine mechanical properties, and digital colorimetry to determine initial color and color stability. In vitro antibacterial activity was measured for 4 months using atomic absorption spectroscopy.
Result: Increase in AgBz concentration darkened the sealants but increase in BOC concentration lightened the color, and at lower concentrations of AgBz (≤0.05 wt%) BOC was able to “whiten” the resin to clinically acceptable levels. Most experimental formulations had comparable hardness, moduli and ultimate transverse strength (UTS) to controls, with many formulations having higher mechanical properties. In general, increase in AgBz concentration tends to increase hardness, moduli, and UTS, but increase in BOC concentration tends to decrease them. All experimental groups released significant amounts of Ag+ ion for up to 4 months in a dose dependent manner.
Conclusion: AgNP and BOC-loaded Ultraseal XT® Hydro™ with comparable mechanical properties and esthetic properties as controls has been developed. All experimental groups released significant amounts of Ag+ ions for up to 4 months. In vitro antimicrobial activity utilizing Streptococcus mutans and Lactobacillus acidophilus is currently being conducted.