The present study was conducted to determine the effects of cadmium (Cd) and lipopolysaccharide (LPS) on periodontal tissue by quantifyLng inflammatory cytokines and prostaglandin E_2 (PGE_2) released from human gingival (GF cells) and periodontal ligament fibroblasts (PGF cells) in culture. Also, the concentration of Cd in stimulated saliva was determined, to study the effect of Cd in cigarettes on the oral cavity. GF cells and PGF cells were isolated by an explant curture method from adult gingival tissue. Monolayer cultures of both types of fibroblast cells were grown in Eagle's MEM supplemented with 10% heat inactivated fetal calf serum. Cultures were incubated at 37℃ in a humidified atmosphere of 5% CO_2-95% air. After a 24-hr preincubation, 10^<-9>-10^<-3>mM of Cd as a CdCl_2 aqueous solution and/or 1-100μg/ml of LPS (E. Coli) as an LPS powder aqueous solution was added to the cultures. Inflammatory cytokines (IL-1β, IL-6, IL-8) and PGE_2 levels in the culture medium were measured using an ELISA method. We found that IL-6, IL-8 and PGE_2 were released from both types of fibroblasts in the presence of Cd or LPS added alone, and that IL-6 and IL-8 were released at remarkably higher levels from GF cells in the presence of Cd and LPS added together. Furthermore, the Cd concentration in stimulated saliva was found to be higher in smokers than in non-smokers. These findings suggest that Cd may aggravate periodontal diseases, and that Cd in cigarettes may serve as a risk factor for periodontal diseases.

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The effects of tongue cleaning and mouthwash on physiological breath odor were determined using the concentration of volatile sulfur compounds (VSCs ; hydrogen sulfide, methyl mercaptan, dimethyl sulfide) in the mouth air and the number of bacteria in the tongue coat as indicators. Adult Japanese males were divided into 5 Groups (Groups A to E) as follows : Group A, oral care not conducted ; Group B, gargled with tap water after every meal ; Group C, cleaned tongue after every meal and then gargled with tap water like Group B ; Group D, gargled after every meal with mouthwash containing chlorhexidine gluconate and then gargled with plain tap water like Group B ; and Group E, cleaned tongue after every meal and then gargled with mouthwash and tap water like Group D. The concentrations of VSCs after breakfast and oral care were significantly lower in all groups compared to those before starting the experiments. The concentrations of all VSCs began to rise 3 hours after breakfast and were significantly higher in Groups A and B than in Groups C, D, and E. The VSC concentrations 24 hours after starting the experiments (before breakfast the following day) in Groups A and B were at the same level as those when the experiments were started. The VSC concentrations in Groups C, D, and E were somewhat elevated compared to those before lunch on the previous day, however, the concentrations were significantly lower than those in Groups A and B (except for methyl mercaptan in Group B), and were significantly lower than those before starting the experiments. Between 10^6 and 10^7 aerobic and anaerobic bacteria were detected from tongue cleaning specimens obtained before starting the experiments (before breakfast). The number of bacteria after starting the experiments decreased in almost all experimental groups and for almost all species of bacteria after breakfast and following oral care, and the number increased again slightly until breakfast the next day. These results suggest that the concentrations of VSCs decrease regardless of oral care, and that tongue cleaning and the use of mouthwash are effective for physiological breath odor.

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The ability of mastication was evaluated by the chewing gum method and by assessing the occlusal force using an occlusal pressure measuring system (DENTAL PRESCALE^[○!R]) in 141 preschool children (mean age : 6.1±0.3 years) who regularly attended kindergarten and nursery school. Furthermore, a questionnaire survey about the dietary and living behaviors of these children was conducted targeting their custodians and teachers, and the correlation of the ability of mastication in children with their dietary and living behaviors was examined. The results were as follows. 1 . There were no sex differences in the amount of sugar elution from gum per unit time or in occlusal force as measured by the DENTAL PRESCALE^[○!R] in the preschool children. The amount of sugar elution was significantly correlated with the body height. 2. The subjective evaluation of the chewing ability in the preschool children by the custodians tended to differ from that by the teachers. 3 . The amount of sugar elution was significantly higher in the children having a well-balanced diet as evaluated by the custodians, than in the children having an unbalanced diet. 4. In the children whose custodians consciously added tough food to meals, the occlusal force as measured by the DENTAL PRESCALE^[○!R] was significantly higher than that in the other children. 5. The amount of sugar elution in the children"who play with their friends very much"as evaluated by the teachers, was significantly higher than that in the other children. These results suggested that the ability of mastication in the preschool children was correlated with their dietary and living behaviors, and highlighted the importance of dietary education for children and their custodians.

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The purpose of this study was to compare the numbers of Candida species present in the mouths of denture wearers to those in non-denture wearers, as well as to examine the relationship of these species to Candida albicans, which is considered to be the primary pathogenic fungus of artificial denture wearers. The study groups consisted of 89 denture wearers (mean age, 63.8±9.8 years ; range, 43-84 years), and 197 non-denture wearers (mean age, 47.1±11.1 years ; range, 25-80 years). Saliva was sampled from each subject and the separation and cultivation of Condida were performed using CHROMagar Candida^[○!R]. The rate of individuals positive for Candida albicans was high regardless of whether the person wore dentures, and the rate of infection was not age-dependent. On the other hand, the positive rate of C.tropicalis, a cause of serious opportunistic infections, as well as the positive rate of C.glabrata, appeared to be higher among denture wearers. It could be suggested that the change in the environment due to the insertion of prosthetic teeth permitted the observed higher incidence of C.tropicalis and C.glabrata in the mouth. Although infection by C.albicans is considered to be the primary target for the control of Candida fungi in individuals who have artificial teeth, our data indicate that two other species, C.tropicalis and C.glabrata, must also be controlled.

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There has been no nation wide research on dental health in 3-year-old children by municipality. Moreover, a problem arises when comparing the results among areas with different populations ; in an area with a small population, the dental caries prevalence rate is sharply affected by the members. This study was performed to calculate the empirical Bayes estimator of the dental caries prevalence rate in 3-year-old children of various municipalities, to draw illness maps of the prevalence rate, and to then compare the prevalence rates among areas on the illness maps. Moreover, the correlations between the estimator and the dental health indices were examined after adjusting for social background factors. Results were obtained for 3,1 12 municipalities in 1998, and data were collected for all municipalities (3,224) in 2000. Regional differences between the prevalence rates of 1998 and 2000, and a 2-year reduction of the prevalence rate were found using the illness maps. Multiple linear regression analysis showed that the estimator was greatly affected by better education, total fertility rate, kind of industry, and unemployment rate (partial correlation coefficient = -0.424, 0.214, - 0.204, and 0.149, respectively) The frequency of dental health guidance had a small influence (partial correlation coefficient = -0.067) (p<0.001). Regional differences between the dental caries prevalence rates in 3-year-old children were found using the illness maps of the empirical Bayes estimator. The frequency of dental health guidance tended to decrease the prevalence rate slightly.

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