Abstract:

Objective　To evaluate the inhibitory effects of topical application of specific immunoglobulin yolk antibodies (IgY) tomutans streptococcion composition of human dental plaque.Methods　Atotal of 24 healthy adult volunteerswere select- ed and randomly distributed into three experimental groups. After a supragingival scaling, the subjects were treated with an appli- cation of IgY containing spray (test group,n=9), a 0.15% chlorhexidine(CH) spray(positive control group,n=9) or a placebo phosphate buffered saline(PBS) spray without any active ingredients(negative control group,n=6) three times daily for three weeks. Pooled plaque samples from the smooth surfaces of teeth were collected for microbiologic analysis before administration (baseline,day 0)、during treatment(days 7、14 and 21)and after withdrawal of the agents(days 28、42 and 56)and plaque index were recorded.Microbial cultivation were performed by serially diluting the samples with PBS solution and cultivating the aliquots on mitis salivarius agar(MS) andMS supplemented with bacitracin (MSB) fororal streptococciandmutans streptococcirespective- ly. The number of colony-forming unit (CFU) per plate was counted and the percentage ofmutans streptococciperoral streptococci in dental plaque were determined. The effect of IgY on colonization ofmutans streptococciwere analyzed by an analysis of variance (ANOVA).Results　The plaque indexes remained unchanged,butmutans streptococciin dental plaque was suppressed signifi- cantly following a shortterm(threeweeks) application of IgY, and lowlevel ofmutans streptococcipersisted for at least 5 weeks af- terwithdrawal of IgY.Conclusion　The results suggest that the immunization with specific immunoglobulin yolk againstmutans streptococcicould be useful for long term suppression ofmutans streptococcicolonization in human dental plaque.

Key words: immunoglobulin yolk antibodies(IgY), dental plaque, mutans streptococci, oral streptococci