Development of an Antibacterial Dentin Adhesive

Nisin is a peptide that possesses potent antibacterial properties. This study evaluated the antibacterial activity of a nisin-doped adhesive against Streptococcus mutans, as well as its degree of conversion and microtensile bond strength (mu TBS) to dentin. Nisin was added to the adhesive Adper Single Bond 2 (3M ESPE), resulting in four groups: Control Group (Single Bond 2); Group 1% (1 wt% nisin-incorporated), Group 3% (3 wt% nisin-incorporated) and Group 5% (5 wt% nisin-incorporated). Antibacterial activity against S. mutans was evaluated using colony-forming unit counts (CFU). The degree of conversion was tested using FTIR. Forty human teeth were restored for mu TBS evaluation. Data were statistically analyzed with ANOVA and Tukey tests at alpha = 0.05. The nisin-doped adhesives, for all concentrations, exhibited a significant inhibition of the growth of S. mutans (p < 0.05); Incorporation of 5% and 3% nisin decreased the degree of conversion of the adhesive (p < 0.05). The mu TBS (in MPa): Control Group-38.3 +/- 2.3(A), Group 1%-35.6 +/- 2.1(A), Group 3%-27.1 +/- 1.6(B) and Group 5%-22.3 +/- 1.0(C). Nisin-doped adhesives exerted a bactericidal effect on S. mutans. The mu TBS and degree of conversion of adhesive were not affected after incorporation of 1% nisin.