Association between glucan synthesis by streptococcus mutans and caries incidence in schoolchildren receiving a fluoride mouth rinse.

PURPOSE: To determine whether variation in glucan synthesis by Streptococcus mutans isolates is associated with caries development in children receiving a fluoride mouth rinse (FMR). MATERIALS AND METHODS: Of 122 children (aged 9 to 10 years), 64 had received FMR (FMR(+) group) and the remaining 58 children had not (FMR(-) group). The number of decayed and filled teeth (DFT) and increases in the number of DFT in 1 year (dDFT) were recorded. Saliva samples were collected to isolate the clinical S. mutans strains. The isolates were incubated in heart infusion broth supplemented with 1% sucrose, then the amount of water-insoluble glucan (WIG) formed on a glass tube surface was evaluated. RESULTS: In the FMR(-) group, children carrying S. mutans had a higher DFT (P = 0.039) and tended to have a higher dDFT (P = 0.080) than the others. In the FMR(+) group, although the differences between children with and without S. mutans were not significant, children carrying S. mutans that produced a high amount of WIG had higher dDFT than the other S. mutans-positive children (P = 0.034). CONCLUSIONS: This study revealed that the variation in glucan synthesis by S. mutans is associated with caries development in children receiving a FMR.

Relationships between the amount of saliva and medications in elderly individuals.

OBJECTIVE: To investigate medications that are related to volume of saliva in the elderly. BACKGROUND DATA: In the elderly, many cases of mouth dryness may represent side effects of medication. MATERIALS AND METHODS: The volume of unstimulated saliva was measured for 30 s (cotton roll test), and with stimulation for 3 min (gum test) in 368 subjects 79-80 years old (177 men, 191 women). Medications were investigated using subject's medication notebooks. RESULTS: Mean volumes of unstimulated and stimulated saliva were 0.14±0.13 and 4.30±2.54 ml respectively. Significant differences were seen between gender and mean volume of saliva. The volume of unstimulated saliva was 0.16±0.15 ml for men and 0.11±0.10 ml for women. The volume of stimulated saliva was 4.99±2.67 ml for men and 3.67±2.25 ml for women. The percentage of subjects taking medication was 64.7% (238/368). Mean number of medications was 2.08±2.26, with no significant difference with gender (2.01±2.37 for men, 2.16±2.16 for women). In a stepwise multiple regression analysis with volume of saliva as the objective variable and number of drugs by category as explanatory variables, significant explanatory variables in addition to gender and number of medications were blood-coagulating agents, Ca antagonists and peptic ulcer drugs for volume of unstimulated saliva, and diabetes medications and peptic ulcer drugs for volume of stimulated saliva. CONCLUSION: These findings suggest that differences exist between gender in volume of saliva for elderly individuals, and that the volume of saliva is affected by the number and type of medications.

Economic Evaluation of a School-based Combined Program with a Targeted Pit and Fissure Sealant and Fluoride Mouth Rinse in Japan.

BACKGROUND: In Niigata prefecture, Japan, a system has been developed based on a school-based fluoride mouth rinse program as follows; students with caries susceptible teeth are screened in a school dental examination, and encouraged to receive sealant placement in local dental clinics. However, the cost-effectiveness of sealant application in the public health has been questioned. The aim of this study was to estimate of the cost-effectiveness and cost-benefit ratio for a school-based combined program with fluoride mouth rinse and targeted fissure sealant in children residing in non-fluoridated areas in Japan. PARTICIPANTS: The analysis was based on comparing an intervention group with two cohorts in the 8-year-old (n=66) and 11-year-old (n=58) participating in the combined program for four and seven years, respectively, with a control group of the same grades (n=43 and n=54 respectively). METHODS: The study measured mean differences in number of decayed and filled teeth (DFT) between the study groups and a combined program cost per child during study periods. The cost-effectiveness ratio was expressed as an individual annual program cost per DFT averted. In the cost-benefit ratio the mean difference in treatment cost between groups (program benefit) was compared to program cost. RESULTS: The mean reduced DFT differences between groups were 1.44 in 8-year-old and 3.17 in 11-year-old children. The cost-effectiveness ratio was ¥ 493 in the 8-year-old and ¥ 202 in the 11-year-old, respectively. The cost-benefit ratio was 1.84 in 8-year-old children and 2.42 in 11-year-old. CONCLUSION: This combined program indicated acceptable cost-effectiveness and cost -benefit ratio.

Long-term follow-up of the effects of a school-based caries preventive programme involving fluoride mouth rinse and targeted fissure sealant: evaluation at 20 years old.

AIMS: The evaluation of long-term effects five years after the completion of a school-based caries prevention programme combined with fluoride mouth rinse (FMR) and targeted sealant application (TS). PARTICIPANTS: 46 subjects in the FMR+TS group and 55 subjects in the FMR group, who were 20 -21 years old, were analysed. They had participated in each 11-year programme, underwent a dental examination at the age of 20 years and answered a self-administered questionnaire. METHODS: The caries prevalence and mean DMFT were calculated, and differences between the two groups were analysed by the chi2 test and Mann-Whitney test, respectively. Logistic and multiple regression analyses were performed using sex, group, and five questionnaire items as independent variables. RESULTS: The caries prevalence and mean DMFT (SD) was 28.3%, 1.56 (3.00) in the FMR+TS group and 60.0%, 2.20 (2.44) in the FMR group, and the difference was significant respectively. In the logistic regression analysis the odds ratio of the FMR+TS group to the FMR group was 0.28 (p < 0.05). CONCLUSIONS: The caries-preventive effects of a school-based combined programme with FMR and TS continued for more than five years after the programme until the age of 20 years.

Predictors of dental caries development in 1.5-year-old high-risk children in the Japanese public health service.

OBJECTIVES: The purpose of this study was to construct prediction models for 1.5-year-old children who were at risk for the development of caries. METHODS: The participants were 5,107 Japanese children who resided in 21 municipalities in the Shizuoka prefecture and received oral health examinations at both 1.5 and 3 years old. General practitioners in the respective municipalities conducted the examination and the evaluation of plaque deposit. At the examination at 1.5 years old, the guardians were asked to complete a questionnaire concerning the child care environment and the health habits of the children and themselves. They were divided into four groups based on the population of the concerned municipality. Approximately 30 percent of the subjects in each group were found to be in the high-risk category (deltadft > or = 1 during both examinations). A stepwise multivariate logistic regression analysis in each group was performed using high-risk subjects as the dependent variable and 28 independent variables from the examination at 1.5 years old and the questionnaire. RESULTS: A significant model could be constructed for each group using eight to 14 independent variables, respectively. The variables common to more than three groups are related to the child's characteristics, especially sugar consumption, feeding, and caries experiences. The predictive ability of the models had a sensitivity of 58.0 to 64.0 percent and a specificity of 64.1 to 70.5 percent. Because the negative predictive value was 77.4 to 80.5 percent, these models might be considered to be in the permissible range. CONCLUSIONS: The models could not predict caries risk but may be able to predict those cases who will not develop caries.

Influence of a fluoride mouthrinse on mutans streptococci in schoolchildren.

This study aimed to determine whether the long-term use of a fluoride mouthrinse affects the salivary levels of mutans streptococci. Two hundred and fifteen schoolchildren (aged 9-10 years) participated. One hundred and forty-nine of these children had used a fluoride mouthrinse since 5 years of age at nursery school, and the remaining 66 children had not. DFT (decayed and filled teeth) was recorded, and the salivary levels of Streptococcus mutans and Streptococcus sobrinus were measured using mitis salivarius bacitracin agar. The group that had used a fluoride mouthrinse had a significantly lower prevalence of both S. mutans and S. sobrinus (p = 0.038) and a significantly lower DFT score (p < 0.001) than the other group. Using logistic regression analysis including caries experience at baseline as a dependent variable, the odds ratio of carrying S. mutans alone was 8.0 (p = 0.066) and that of carrying both S. mutans and S. sobrinus was 16.5 (p = 0.022) in the group that had not used the fluoride mouthrinse. Children carrying both S. mutans and S. sobrinus had a higher caries incidence in 1 year than the others, with odds ratios of 5.73 (p = 0.067) in the group with a fluoride mouthrinse and 3.47 (p = 0.035) in the group without it. These results show that the long-term use of a fluoride mouthrinse is associated with reduced salivary levels of mutans streptococci and this bacterial reduction may partly contribute to the suppression of dental caries in children using a long-term fluoride mouthrinse.