Yoshihide Okazaki

Culture-based PCR analysis of plaque samples of Japanese school children to assess the presence of six common cariogenic bacteria and its association with caries risk.

The aim of the study was to assess the presence of six common cariogenic bacteria from Cariostat-inoculated plaque samples of Japanese elementary school children through PCR analysis and check its associations with caries risk testing the validity of Cariostat as a caries risk assessment tool. This epidemiological school-based study investigated plaque samples of 399 Japanese elementary school children. Assessed using the Cariostat, 48.2% of the children had high caries risk. DNA detection of Streptococcus mutans, Streptococcus sobrinus, Streptococcus salivarius, Lactobacillus casei, Lactobacillus plantarum, Lactobacillus fermentum and both S. mutans and S. sobrinus was seen in 65.2%, 24.1%, 69.7%, 17.5%, 7.8%, 19.3%, and 17.3% of the participants, respectively. Except for S. salivarius, the presence of all other investigated bacteria resulted in a statistically significant increase among the proportion of subjects with high caries risk. Caries risk assessed using Cariostat was significantly influenced by the presence of cariogenic bacteria. Being a selective medium for cariogenic bacteria, the Cariostat can be a useful and direct source of cariogenic bacterial DNA for PCR analysis while effectively assessing caries risk.

Cariogenic Bacteria and Caries Risk in Elderly Japanese Aged 80 and Older with at Least 20 Teeth

OBJECTIVES: To assess caries risk and check the presence of four commonly found oral cariogenic bacteria in “8020” achievers.

Risk behaviors and its association with caries activity and dental caries in Japanese children

Abstract The aim of this study was to assess risk behaviors and its association with caries activity and dental caries in Japanese children. The subjects were 392 young Japanese children who underwent dental health check-up at 18, 30 and 42 months of age. Oral examinations, Cariostat tests and dental health questionnaires were carried out at each time. The caries prevalence of children was 1.5% at 18 months, 9.9% at 30 months and 28.1% at 42 months. Caries activity based on the Cariostat scores of children was correlated with caries status (caries-free/carious) at 42 months. In children with caries during each examination period at 42 months, eating snacks while playing was ranked as the most important behavioral risk ( P P P P P P P

Presence of Streptococcus mutans or Streptococcus sobrinus in Cariostat®-inoculated plaque samples from Japanese mother-child pairs

Abstract The aim of this study was to determine the presence of Streptococcus mutans or Streptococcus sobrinus in Cariostat-inoculated plaque samples obtained from Japanese mother-child pairs through a conventional PCR technique and to establish the presence of these bacteria and caries risk. Oral examination and caries risk assessment using the Cariostat ® were carried out on 168 children, aged 6–31 months, and their mothers. The presence of S. mutans and S. sobrinus in Cariostat-inoculated plaque samples was checked through PCR and tested for relevance with caries risk. A significant correlation ( P S. mutans or S. sobrinus in plaque samples from their children in the 19–31-month-old age range. However, no significant relationship found between the presence of either strain in the plaque of younger children (6–18 months) and caries risk of mothers. Likewise, high caries risk was seen in 49.1% of the 19–31-month-old children of highrisk mothers ( P P S. mutans and S. sobrinus in plaque samples obtained from mothers and their children through conventional PCR techniques.

Caries activity test in Mongolian and Japanese children

Abstract The main objective of this study was to investigate the relationship between a caries activity test (CAT21 Test), and caries status. The subjects of this study were 419 preschool children, of Okayama City, Japan and, of Ulaanbaatar City, Mongolia. In all, subjects were examined for dental caries using a mouth mirror and probe. Then buccal plaque samples were obtained, incubated at 37°C for 48 hours, and scored as per the manufacturers instructions for the Cariostat method. The following results were obtained: 1.The caries prevalence and mean deft of the two subjects was 55.0% and 3.2 for Japanese, so 92.4% and 6.6 for Mongolians, respectively. 2.Results of the CAT21 Test score distribution are as follows: 14% of the Japanese, 7.6% of the Mongolians had a CAT score of 0 (very low risk), 38% of the Japanese, 12.4% of the Mongolians had a 1.0 (low risk), 16.3% of the Japanese, 17.9% of the Mongolians had a 2.0 (middle risk), 25.5% of the Japanese, 36.6% of the Mongolians had a 3.0 (high risk), and 6.2% of the Japanese, 25.5% of the Mongolians had a 4.0 (very high risk) score. 3.There was a statistically significant difference in the CAT21 Test scores and dental caries indices of Japanese and Mongolian preschool children (ANOVA P From these results, it was suggested that the CAT21 Test is useful in clinical application

The relationship between body balance function and occlusal function during the mixed dentition period

Abstract The aim of this study was to investigate the relation between body balance and occlusal balance during the mixed dentition stage. Fifty-six healthy children with Hellmans Dental Age IIIA: (31 boys and 25 girls) with an average age of 8.1 years, were selected from an elementary school. The body balance, distance and area of gravity center movement (GCM) were measured with automatic posture analytical devices. Occlusal abilities were measured with pressure-sensitive sheets (Dental Prescale ® ), including occlusal contacts area, average occlusal pressure, maximum occlusal pressure, occlusal force and occlusal balance. Analysis of occlusal balance was determined by separating the middle group (| x |≤5mm) from the deflection group (| x |>5mm) based on the position of occlusal balance center. Similarly, the children were instructed to perform the GCM area of eyes-closed exercise. The first 25% of the participants with the best balance were grouped as the good balance group; and the last 25% with the worse balance were grouped as the bad balance group. Results showed that occlusal contact area and occlusal force of the middle group were more than the deflection group, GCM distance and area of the middle group were less than the deflection group. occlusal contacts area and occlusal force of the good balance group were more than the bad group. Body balance function and occlusal balance function were observed to have mutual influence during Hellmans Dental Age IIIA stage in this study.

Associations between caries activity, salivary buffer tests and caries increment in Mongolian children

Abstract The aim of the study was to evaluate caries increment in combination with a caries activity test (CAT21 Test) and a salivary buffer test (CAT21 Buf Test)—to predict future caries activity in Mongolian preschool children living in Ulaanbaatar City. The effectiveness of combining both tests and deft (decayed, extracted, filled teeth) means was also investigated. The caries prevalence in subjects was 94%, and deft mean value was 6.8. The caries increment after one year was 2.3 teeth. From the distribution of CAT21 Test scores a low risk was found in 38.6% and high risk in 61.4% of the examined children. From the CAT21 Buf Test scores, the high risk (lower buffer capacity) was found in 79.8% of the examined children. When the combination CAT21 Test and CAT21 Buf Test scores were divided into four groups (low-low/lowhigh/ high-low/high-high), the mean def-teeth showed a significant difference among the four groups (ANOVA P P

Level of caries activity and an estimate in the increase of permanent teeth caries: a three-year follow up study in preschool senior children

Abstract The aim of this study was to examine relationships between the level of caries activity in preschool senior children and the increase of dental caries 3 years after the permanent teeth erupted. A total of 1133 preschool senior children aged 5–6 years were examined yearly during 3-year duration. A Caries Activity Test (Cariostat Test) was used at the first examination of this study. The results were as follows; 1.The caries prevalence rate of the subjects was 84.1% and the mean dft was 5.89 at the first examination. 2.There was a significant relationship between the CAT score and dft at the first examination (P 3.The subjects were divided into 3 risk groups by CAT score: low-risk group (20.4%), middle-risk group (43.3%) and high-risk group (36.3%). 4.Increments of DFT from 1 year to 3 years after the permanent tooth erupted for the high-risk group were more than twice for those of the low-risk group (P The results showed that the usage of the CAT Test for preschool senior children was useful to predict increase in permanent teeth caries over 3-year duration.

The relationship between the salivary buffer capacity test (CAT21 Buf Test) results and caries status in Mongolian preschool children

Abstract This study was conducted to investigate the relationship between results of a salivary buffer test (CAT21 Buf Test) and caries status in 507 preschool children, who were 4–6 years old in Ulaanbaatar City, Mongolia. The prevalence of caries in the preschool children was 96.1%, and the mean deft and d teeth were 8.1 and 7.2, respectively. The mean CAT21 Buf Test score was 53.3% for low risk (high buffer capacity) and 46.7% for high risk (low buffer capacity). When salivary buffer score was divided into two groups (high risk, low risk), mean deft differed a significantly between the two groups (ANOVA P