The effect of a mouthrinse based on nisin, a bacteriocin, on developing plaque and gingivitis in beagle dogs.

The aim of this study was to evaluate the effect of nisin, an antimicrobial peptide, on the development of plaque and gingivitis in beagle dogs when compared with 0.12% chlorhexidine and a placebo. 16 female beagle dogs 1 year of age were brought to optimum gingival health by scaling, root planing and polishing. At the conclusion of the pretreatment phase, the dogs were divided into 4 groups for the application of the test agents and were placed on a plaque promoting diet of Purina Dog Chow softened with water. Test agents included 100 micrograms/ml nisin and 300 micrograms/ml nisin formulated in a vehicle containing 1 mM NaEDTA; negative control comprised of exactly the same formulation but omitting nisin; and 0.12% chlorhexidine as Peridex. Throughout the treatment period, formulations were applied 2x daily to premolar teeth in each quadrant for 1 min using a Monojet syringe. The development of plaque and gingivitis was monitored at 15, 27, 39, 53, 74 and 88 days during the treatment phase using standard measurements of gingival index, plaque index, stain index and bleeding to probing. Throughout the treatment phase, plaque accumulation increased in all groups, but the rate of plaque build-up was less in groups treated with either nisin or chlorhexidine formulations compared with the placebo treated group. The gingival index of dogs in all groups increased throughout the study period. However, from day 27 onward, the groups receiving nisin had lower gingival index scores than did the placebo group.(ABSTRACT TRUNCATED AT 250 WORDS)