Masaharu Miyagi

Effects of fluoride intake on the mineral content, acid solubility and resorption caused by experimental periodontitis of rat alveolar bone

Adult rats were given either distilled water or drinking water containing 100 parts/10(6) of fluoride. The alveolar bone of rats given fluoride for 90 days showed an increased mineral content and decreased acid solubility compared to the bone of rats given distilled water. Experimental periodontitis was initiated in both groups after 110 days of treatment to cause alveolar bone resorption. Fourteen days later, the rats were killed and it was found that the alveolar bone resorption caused by experimental periodontitis was significantly smaller in the rats given fluoride in their drinking water than in those given distilled water. The findings suggest that fluoride intake might have a protective effect on rapidly progressing alveolar bone resorption.

Maternal and Child Dental Health Care at a Public Health Center. II. Relationship between Caries Increment and Life Style in 1.5-year-old Children with and without Caries.

The purpose of this study was to extract the factors which affect the caries increment between 1.5 and 3 years of age by dividing the subjects into two groups, one with and the other without caries at 1.5 years of age.The subjects were 1641 children who received a 3-year-old dental health examination at a public health center in Hiroshima City between April 1990 and November 1991.Eight factors associated with caries prevalence at 3 years of age were examined using multivariate analysis. These factors were ‘Family type’, ‘Order of birth’, ‘Interruption of breast feeding’, ‘Bottle feeding at 1.5 years of age’, ‘Regularity of between-meal snacks’, ‘Drinking sugary beverages’, ‘Watching TV at meals’ and ‘Tooth brushing with mothers help’.The results were as follows.1) The factors related to caries increment from 1.5 to 3 years of age for the children without caries at 1.5 years of age were ‘Drinking sugary beverages’, ‘Interruption of breast feeding’, ‘Watching TV at meals’ and ‘Bottle feeding at 1.5 years of age’, and for the children with caries at 1.5 years of age the factor was ‘Tooth brushing with mothers help’.2) We suggest that more efficient dental health guidance should be given at a 1.5-year-old dental health examination.3) The screening method with the eight variables was valid for prediction of caries increment in the children with caries, but not in the children without caries.