Effects on plaque formation of the bacteriolytic enzyme derived from Streptomyces globisporus strain 1829

Abstract

Dental plaque plays a decisive role in the initation and development of dental caries and marginal periodontal disease. Inhibition and control of the microbial deposition onto tooth surface is a prerequisite for preventing these oral diseases.A new bacteriolytic enzyme derived from Streptomyces globisporus strain 1829 has been shown to be active against various strains of pathogenic plaque microorganisms. The purpose of the present report was to study the effect of the lytic enzyme preparation on the formation of dental plaque in humans and to determine the capability of the enzyme for preventing plaque growth under conditions similar to daily life but without tooth brushing.Eleven male volunteers, 23 to 28 years old, who had clinically healthy gingiva and no carious lesions were instructed to withdraw active oral hygiene procedures. The enzyme was administered into their oral cavity by inserting a chewable tablet (troche) in the mucobuccal fold of upper molar or by vigorous rinsing for one minute with mouthwash after each meals for 3 days. Bacterial plaques deposited on the buccal surfaces of the maxillary second premolar and first and second molars were collected and weighed, and plaques onto the labial surfacees of maxillary and mandibular anterior teeth were stained, photographed and evaluated.With the troche method, a relatively high level of the enzyme activity in the oral cavity persisted for a certain period, and the plaque deposition was apparently inhibited by the administration of the lytic enzyme at a dose of 23, 000 to 46, 000 units per day, which was statistically significant. With the mouth-rinsing method, on the other hand, the majority of the lytic enzyme activity disappeared from the oral cavity shortly after rinsing, but plaque accumulation was apt to be inhibited by the rinse with the enzyme of 18, 000 units per day. Rinsing with the placebo mouthwash was also effective to some extent in retarding microbial deposition on the tooth surface.The plaque samples obtained from the lytic enzyme-treated group and the placebo group were analysed both chemically and microbiologically, and the results did not show any significant differences between the groups in total hexosamine, total reducing power, protein and calcium content and in viable cell numbers of streptococci.It is concluded from the results that this bacteriolytic enzyme may contribute to the prevention and control of plaque formation.