Association Between Dental Caries Prevalence and Stress Levels in Japanese Children.

Introduction Early life stress (ELS) caused by abuse and bullying has increased dramatically, however, effective means for accurate detection have not been found. Some decades ago, an association between stress and dental caries was suggested. However, even now, stress is not recognized widely as a potential risk factor for caries. Therefore, the purpose of this study was to verify the possible effects of stress by comparing them to the effects of saliva factors and the microorganisms that pose a general caries risk. Methods We conducted cross-sectional observation research on 30 children with mental problems, diagnosed as 'stressed,' and 30 age-matched unstressed children in the same elementary school. An oral examination (dental caries diagnosis) and an oral environment survey (saliva test) were carried out in 2007. Further, the concentration and activity of salivary stress proteins were measured. All variables were statistically analyzed using the Mann-Whitney U test, correlation, and multivariate analysis. Results The dental caries experience ratio was significantly higher in the stress group, and only the concentration of CgA, a salivary stress protein, showed a significant difference. Unexpectedly, we did not detect any differences in the rates and counts of cariogenic bacteria or salivary buffering activity. Binomial logistic regression analysis only showed significance in the presence or absence of ELS. Conclusion Stress factors may have a stronger influence on caries development in the stress group than in the general caries risk. Therefore, long-term stress, causing changes in the children's bodies, might hint at important factors leading to the development of dental caries.

Development of small-scale water fluoridation equipment.

PURPOSE: A water fluoridation program launched in the United States in 1945 has become a worldwide application for caries prevention. Although such a program is important in Japan, water fluoridation in large communities has not been established. This study aimed to develop safe small-scale water fluoride equipment that can be easily used to carry out water fluoridation programs in areas with children in long-term care facilities, and in developing countries without water supply facilities. METHODS: Batch-type NaF addition adjustment equipment was manufactured as small-scale water fluoride equipment. The fluoride concentration of the adjusted water with this equipment was measured using an ion meter and a fluoride composite electrode. All 51 water quality standards set by the Ministry of Health, Labour, and Welfare of Japan were tested. RESULTS: The fluoride ion concentration of the adjusted water was 0.7 mg/L and it was constant and stable. The adjusted water conformed to the water quality standard values of the Japanese Water Supply Law. CONCLUSION: Water produced with small-scale water fluoridation equipment had a fluoride concentration of 0.7 mg/L, which is the recommended concentration for caries prevention. The fluoride concentration was stable.

The Candida species that are important for the development of atrophic glossitis in xerostomia patients.

BACKGROUND: The purpose of this study was to clarify the species of Candida that are important for the development of atrophic glossitis in xerostomia patients. METHODS: A total of 231 patients with subjective dry mouth were enrolled in the present study. Logistic regression analysis was performed to clarify the contribution of each Candida species and other variables to the development of atrophic glossitis. The dependent variable was the absence/presence of atrophic glossitis. The Candida colony-forming units (CFU) of C. albicans, C. glabrata, C. tropicalis, and C. krusei, as well as age, gender, resting (RSFR) and stimulated (SSFR) whole salivary flow rate, and denture-wearing status, were treated as explanatory variables. RESULTS: Logistic regression analysis showed that two factors were closely associated with the presence of atrophic glossitis: an increase in C. albicans CFU and a decrease in the SSFR. CONCLUSIONS: C. albicans, but not non-albicans Candida, was associated with atrophic glossitis in xerostomia patients who had no systemic predisposing factors, indicating that C. albicans remains a treatment target for Candida-related atrophic glossitis.

Effects of oral moisturising gel containing egg yolk antibodies against Candida albicans in older people.

OBJECTIVE: The aim of this study was to evaluate the inhibitory effects of oral moisturising gel containing egg yolk antibody against Candida albicans (anti-CA IgY) in older people. Therefore, we measured the number of Candia CFU present on oral swabs at baseline and after using the gel. METHODS: A randomised, double-blind, placebo-controlled trial was conducted among volunteers living in a nursing home in Japan. The participants were divided into two groups. The group 1 participants received oral care using an experimental oral moisturising gel with anti-CA IgY, and those in group 2 received oral care using a placebo oral moisturising gel without anti-CA IgY. The oral care was performed by care workers three times a day for 4 weeks. The participants' tongues were sampled using a swab method at baseline and after 2 and 4 weeks of using the oral gel, and the number of C. albicans, Candida tropicalis and Candida krusei colonies was counted. RESULTS: The baseline oral condition of the participants in the two groups did not differ significantly. The experimental gel significantly reduced the number of C. albicans colonies from baseline to after 4 weeks of using the oral gel; however, no significant reductions were observed in the number of C. tropicalis or C. krusei colonies. CONCLUSION: The use of oral moisturising gel containing anti-CA IgY for 1 month significantly reduces the number of C. albicans CFU present on swabs in older people.

Factors associated with the presence of atrophic tongue in patients with dry mouth.

PURPOSE: This study aimed to identify factors associated with atrophic tongue in patients with dry mouth. METHODS: Discriminant analysis was performed in 1265 patients with dry mouth to identify factors that might influence the risk of developing atrophic tongue. The dependent variable was the presence of atrophic tongue, while patient age, resting saliva flow rate, stimulated saliva flow rate and Candida colony-forming units (CFU) were used as the independent variables. RESULTS: The standardised linear discriminant coefficients showed that Candida CFU, stimulated saliva flow rate and age were significantly associated with the presence of atrophic tongue. The following linear discriminant function was obtained: z = 0.024 × age - 0.63 × (resting saliva flow rate) - 0.81 × (stimulated saliva flow rate) + 0.002 × Candida CFU - 0.611. CONCLUSION: High Candida CFU, low stimulated saliva flow rate and advanced age were identified as closely associated factors for the risk of development of atrophic tongue.

Efficacy of Fungiflora Y staining for the diagnosis of oral erythematous candidiasis.

OBJECTIVE: The purpose of this study was to investigate the efficacy of Fungiflora Y staining (fluorescent stain) for the diagnosis of erythematous candidiasis. SUBJECTS AND METHODS: This study enrolled 48 patients who were diagnosed with erythematous candidiasis and who underwent fungal culture and microscopic examination of a smear specimen stained with CytoQuick (modification of the Giemsa stain) and Fungiflora Y. Fungiflora Y staining was observed using a portable fluorescent microscope (CyScope(®)). The sensitivity, specificity and positive and negative predictive values were calculated using fungal culture as the gold standard test. Accuracy was calculated, and the difference between the CytoQuick and Fungiflora Y groups was examined using contingency tables and the chi-square test. RESULTS: The sensitivity and specificity of the CytoQuick stain was 0.51 and 0.91, respectively; the positive predictive value was 0.95, and the negative predictive value was 0.36. The sensitivity and specificity of the Fungiflora Y stain was 0.84 and 1.0, respectively; the positive predictive value was 1.00, and the negative predictive value was 0.65. The accuracy of Fungiflora Y (0.88) was superior to that of CytoQuick (0.60) (p = 0.0052). CONCLUSIONS: Microscopic examinations of smear specimens using a combination of Fungiflora Y staining and the CyScope(®) portable fluorescent microscope was found to be useful for the diagnosis of oral erythematous candidiasis.

Study of the clinical usefulness of a dental drug system for selective reduction of mutans streptococci using a case series.

The aim of this study was to evaluate the clinical efficacy and safety of a dental drug delivery system (3DS) for the selective reduction of mutans streptococci. Twenty patients with high levels of mutans streptococci in saliva participated. The efficacy of 0.2% chlorhexidine (CHX) delivered by 3DS in reducing the salivary levels of mutans streptococci compared with total streptococci and lactobacilli was investigated. Each subject was treated by professional mechanical tooth cleaning (PMTC) and subsequently individual trays with CHX for 5 min. Salivary bacterial samples were taken at the baseline and weeks 1-12. A significant reduction in the colony count of mutans streptococci was observed during the first 4 weeks compared with the baseline count, while no significant decrease in the count of total streptococci or lactobacilli was found during 12 weeks. In particular, the proportion of mutans streptococci in total streptococci remained low after 12 weeks. Our results indicate that the new 3DS used in combination with PMTC appears to be a promising intraoral drug delivery system which, when used with a low CHX concentration selectively, effectively reduces mutans streptococci in the oral cavity with no adverse effects.

Screening of periodontitis with salivary enzyme tests.

The purpose of this study was to determine the usefulness of salivary biochemical markers for the screening of periodontal disease and examine the agreement between the results of saliva enzyme tests and those of probing depth. The present study included a total of 187 subjects who underwent annual medical check-ups at the Comprehensive Health Care Center, Honjo, Saitama Prefecture, Japan. Periodontal pocket probing was performed with a WHO probe, and various enzymes and biochemical parameters in saliva were measured. For lactate dehydrogenase (LDH), the proportions of the five isoenzymes were calculated. To decide the cut-off point for each enzymatic activity, receiver operating characteristic curves (ROC curves) were constructed and the points of minimum difference between sensitivity and specificity were decided. Among the biochemical markers tested, salivary LDH level had the highest sensitivity and specificity (sensitivity 0.66, specificity 0.67), while salivary levels of aspartate aminotransferase (AST) and blood urea nitrogen (BUN) also had sensitivity and specificity above 0.60. Among the LDH isoenzymes, LDH4 and LDH5 dominated in whole saliva samples. Salivary LDH may be a feasible and useful parameter for the screening of periodontal disease, while salivary AST and BUN also appear to be potentially useful for this purpose.

Correlation between patient satisfaction and dental clinic credibility in regular dental check-ups in Japan.

The aim of this study was to investigate the relationship between dental clinic credibility and patient satisfaction with regular dental check-ups, to compare the level of satisfaction of patients who had regular check-ups with those who did not, and to identify factors associated with regular dental checkups. Thirty-nine private dental clinics in 17 prefectures throughout Japan participated in this study. A total of 9024 questionnaires were distributed to the patients at these clinics, and patients returned the questionnaires using a pre-paid envelope (response rate 56.8%). The questionnaires consisted of items related to patient demographics and 11 items concerning the level of patient satisfaction with the dental clinic. Using multiple logistic regression analysis, the strongest correlation was found between dental clinic credibility in regular checkups and the technical competence of the dentist. The responses to those items concerning making an appointment, and the cleanliness and neatness of the waiting room were different between patients who had regular check-ups and those who did not. To investigate the factors that encourage regular dental check-ups, correlation of factors with regular check up experience were analyzed. Multivariate-adjusted odds ratios indicated a strong association between regular dental check ups and both the technical competence of the dental hygienist and the cost of treatment.

Characteristics and willingness of patients to pay for regular dental check-ups in Japan.

The purpose of this survey was to investigate the relationship between demographic characteristics and willingness of patients to pay for regular dental check-ups in Japan. Questionnaires were distributed at private dental offices and collected via postage-paid return envelopes addressed to the center of the study groups. Questions focused on demographics and willingness to pay for regular check-ups. Five thousand one hundred thirty-two questionnaires were collected (response rate 56.8%). The 3 groups most likely to have regular dental check-ups were found to be the under 20s, 50 to 59 year olds and civil servants. Of these groups, civil servants were found to be the most likely of all to have regular check-ups. More females than males were represented in the sample. More than 60% of the patients responded that they would be willing to pay for regular check-ups if the cost were less than 2,000 yen (about 20 dollars). However, no statistically significant differences were observed in relation to household income. The results suggested that participation in regular dental check-ups might be related to gender and age, but not to household income.

Correlation study on oral health and electrocardiogram abnormalities.

The purpose of this study was to investigate the association between periodontal conditions and electrocardiogram test results that were obtained to screen for coronary heart disease risk factors. The present study included a total of 578 subjects who underwent annual medical check-ups at the Total Health Care Center in Otsu, Shiga Prefecture, Japan. To calculate the odds ratios for the electromyography abnormalities, we performed a logistic regression analysis for the oral examination, electrocardiogram, and blood analysis data. The crude odds ratio was obtained by a logistic regression analysis of age, sex, number of missing teeth, number of filled teeth, simplified oral hygiene index, community periodontal index, and blood analysis factors and results indicated there was a statistically significant correlation with the prevalence of electrocardiogram abnormalities. However, electrocardiogram abnormalities have a strong correlation with demographic factors such as sex and age. Therefore the experimental factors representing oral status were reexamined after the odds ratios were adjusted for age and sex. As a result of this adjustment, the new odds ratios that were determined indicated that there were no correlations between the oral factors and the prevalence of electrocardiogram abnormalities.