A Study of Oral Health Condition in the Inhabitants at a Hill (Kotyang) Village in Nepal

We investigated the oral health condition in 221 subjects; 120 men and 101 women of the age 10 to 69 years old, at a hill village, named Kotyang, which located about 50 km east of Kathmandu from August 5 through August 25, 1987. The condition of the oral cavity in each subject was assessed by RD-test which is a simple method of semi-quantitative analysis for bacterial number in the oral cavity. 108 CFU/ml or more of bacterial number were detected in 55.8% of men and in 66.0% of women examined. The estimated numbers of the bacteria in their oral cavities were much more than those of Japanese. The color photographs of the oral cavity of each subject examined were taken and the periodontal status was assessed by means of PMA-index ; P. M and A represent papillary gingiva, marginal gingival and attached gingiva, respectively. The prevalence of periodontal diseases tended to be high as compared with that of Japanese, especially at their age of 50s and 60s. The hardness and fluorine contents in drinking water at several places in the village were 9-5lppm and 0.13-0.32ppm, respectively. This may have no effect on the occurrence of defect of dental calcification in the inhabitants in Kotyang

Reduction of Streptococcus mutans Adherence and Dental Biofilm Formation by Surface Treatment with Phosphorylated Polyethylene Glycol▿

Initial attachment of the cariogenic Streptococcus mutans onto dental enamel is largely promoted by the adsorption of specific salivary proteins on enamel surface. Some phosphorylated salivary proteins were found to reduce S. mutans adhesion by competitively inhibiting the adsorption of S. mutans-binding salivary glycoproteins to hydroxyapatite (HA). The aim of this study was to develop antiadherence compounds for preventing dental biofilm development. We synthesized phosphorylated polyethylene glycol (PEG) derivatives and examined the possibility of surface pretreatment with them for preventing S. mutans adhesion in vitro and dental biofilm formation in vivo. Pretreatment of the HA surface with methacryloyloxydecyl phosphate (MDP)-PEG prior to saliva incubation hydrophilized the surface and thereby reduced salivary protein adsorption and saliva-promoted bacterial attachment to HA. However, when MDP-PEG was added to the saliva-pretreated HA (S-HA) surface, its inhibitory effect on bacterial binding was completely diminished. S. mutans adhesion onto S-HA was successfully reduced by treatment of the surface with pyrophosphate (PP), which desorbs salivary components from S-HA. Treatment of S-HA surfaces with MDP-PEG plus PP completely inhibited saliva-promoted S. mutans adhesion even when followed by additional saliva treatment. Finally, mouthwash with MDP-PEG plus PP prevented de novo biofilm development after thorough teeth cleaning in humans compared to either water or PP alone. We conclude that MDP-PEG plus PP has the potential for use as an antiadherence agent that prevents dental biofilm development

ネパール・コテン村における歯科的調査研究 : 昭和６2年度九州大学海外学術調査報告

We investigated the oral health condition in 221 subjects; 120 men and 101 women of the age 10 to 69 years old, at a hill village, named Kotyang, which located about 50 km east of Kathmandu from August 5 through August 25, 1987. The condition of the oral cavity in each subject was assessed by RD-test which is a simple method of semi-quantitative analysis for bacterial number in the oral cavity. 108 CFU/ml or more of bacterial number were detected in 55.8% of men and in 66.0% of women examined. The estimated numbers of the bacteria in their oral cavities were much more than those of Japanese. The color photographs of the oral cavity of each subject examined were taken and the periodontal status was assessed by means of PMA-index ; P. M and A represent papillary gingiva, marginal gingival and attached gingiva, respectively. The prevalence of periodontal diseases tended to be high as compared with that of Japanese, especially at their age of 50s and 60s. The hardness and fluorine contents in drinking water at several places in the village were 9-5lppm and 0.13-0.32ppm, respectively. This may have no effect on the occurrence of defect of dental calcification in the inhabitants in Kotyang