The effects of mutanase (α-1,3 glucan 3-glucanohydrolase, free of 1,6 activity produced by Trichoderma harzianum OMZ 779) and dextranase (α-1,6 glucan 6-glucanohydrolase obtained from Penicillium funiculosum) on plaque formation and caries incidence were investigated in two groups of 36 rats each. The first group was kept in relative gnotobiosis with Streptococcus mutans OMZ 176 E, the second group harboured its indigenous flora. During the entire 28-day experimental period the animals were housed in a feeding machine and fed 18 meals per day. For the first three experimental days both groups received diet 2,000 (56% sucrose). Thereafter each of the two groups was distributed among the following treatments: O: diet 2,000; M: diet 2,000 containing mutanase (100 MU/ g); D: diet 2,000 containing dextranase (150 DU/g); M+D: diet 2,000 containing both enzymes (100 MU and 150 DU/g). Blood for white cell counts was collected prior to sacrifice by heart puncture. Extent of plaque on the smooth surfaces of the upper molars was scored under a dissection microscope after staining with erythrosin. Fissure caries was assessed on serial sections of the first and second lower molars.

The effect of topically applied mutanase (α-1-3-glucan, 3-glucanohydrolase) on plaque formation and caries in rats was studied in two experiments. Compounds known to strongly inhibit dental caries when topically applied served as controls in both experiments. The first experiment investigated whether or not and in what frequency of application this agent was effective in reducing dental caries. In addition, effects on the composition of the plaque flora were examined. Because this first trial resulted in a surprisingly high degree of caries protection, the findings were reinvestigated in a second experiment. In addition to crude mutanase, a partially purified enzyme preparation was included. In both studies, it was demonstrated that mutanase was as effective as fluoride or chlorhexidine in reducing the caries incidence on smooth surfaces and in fissures. However, neither the extent of smooth surface plaque nor its bacterial composition was affected by the enzyme preparation. The only conceivable mode of action is, therefore, thought to be a change in the diffusion properties of dental plaque. Furthermore, the pronounced effect of topically applied mutanase may only be explained by the presence of adequate receptors in the oral cavity allowing long-term retention and release of the enzyme.

Proximal inlays were seated in contralateral teeth in eight subjects with clinically healthy gingivae. After 23 days, the subgingival area and part of the supragingival surface of one of the inlays was roughened with an abrasive instrument up to 1 mm above the gingival margin; the other inlay remained polished. Gingival fluid flow rate was buccally and lingually measured in the papillary area close to the proximal roughened and polished inlay surfaces and also at papillae beside sound proximal surfaces of the same teeth during a period of 85 days. In addition, plaque was scored and also assessed planimetrically. The mean gingival fluid flow rate was significantly higher adjacent to both the rough and polished filling surfaces when compared with proximal surfaces without restoration. Plaque indices were similar in the vicinity of filled and sound proximal areas irrespective of the gold surface texture. Planimetrically more plaque was formed on the sites of roughened inlays.

No abstract

Water fluoridation was introduced in Basle in 1962. Caries prevalence (DMFS) ten years after fluoridation was, depending on age, 47 percent to 77 percent lower than before fluoridation. The percentage of pupils entering school with caries free deciduous and permanent teeth increased from 6.7 percent in 1961 to 35.3 percent in 1974. Fluoride tablets (0.5-1.0 mg F) distributed at school approximately 200 times a year were highly effective in inhibiting caries. Mean DMFS caries reductions were about 47 percent. Supervised toothbrushing exercises with concentrated fluoride solutions or rinsing tablets 6 times a year combined with repeated information decreased the caries incidence by approximately 50 percent. Caries reductions in anterior teeth were about 80 percent. The supervised toothbrushing was beneficial to the deciduous teeth and the gingiva. Fluoride tablet distribution combined with supervised fluoride toothbrushing yielded higher reductions.