Mitsuo Kishi

Relationship of quantitative salivary levels of Streptococcus mutans and S. sobrinus in mothers to caries status and colonization of mutans streptococci in plaque in their 2.5-year-old children

OBJECTIVES The aim of this study was to assess the relationships of quantitative salivary levels of Streptococcus mutans and S. sobrinus in mothers with the colonization of mutans streptococci (MS) in plaque and caries status in their 2.5-year-old children. Furthermore, the dynamics of caries status in the children was evaluated in a 2-year follow-up survey. METHODS After oral examination of 54 mother-and-child pairs, the saliva samples from the mothers and the plaque samples from the children were collected. The levels (log DNA copies/ml saliva) of S. mutans and S. sobrinus were quantified using real-time polymerase chain reaction (PCR) assays, while MS in the plaque samples were detected using a cultivation method. In addition, 50 of the 54 children participated in a 2-year follow-up survey of caries prevalence. RESULTS In the 2.5-year-old children, the percentage of dft-positive subjects and mean number of dft were significantly higher in the MS(+) group when compared with the MS(-) group. Findings from the 2-year follow-up survey indicated that MS(+) subjects had a persistently higher mean number of dft at 4.5 years. The 2.5-year-old children were divided into three groups based on the quantitative levels of salivary S. mutans and S. sobrinus in their mothers: those whose mothers had low levels of S. mutans (<4 log DNA copies/ml) and S. sobrinus (<2) (group 1); those whose mothers had a high level of S. mutans (> or = 4) and low level of S. sobrinus (<2) (group 2); and those whose mothers had high levels of both (> or = 4 and > or = 2, respectively) (group 3). Among the three groups, the percentages of MS(+) and dft-positive children were highest in group 3 and lowest in group 1. Furthermore, multiple logistic regression analyses revealed that grouping the mothers based on salivary level of S. mutans and S. sobrinus was an efficient means to predict both MS colonization (OR = 2.96) and prevalence of dental caries (OR = 9.39) in children at 2.5 years of age. CONCLUSIONS In the 54 mother-and-child pairs tested, the maternal salivary levels of S. mutans and S. sobrinus determined by real-time PCR were significantly related to MS colonization in plaque as well as dental caries in their children at 2.5 years of age. Thus, determination of maternal levels of both organisms using the present cut-off values is proposed as an efficient method to indicate the risks of maternal transmission of MS and childhood dental caries.

Effects of tongue cleaning on bacterial flora in tongue coating and dental plaque: a crossover study.

BackgroundThe effects of tongue cleaning on reconstruction of bacterial flora in dental plaque and tongue coating itself are obscure. We assessed changes in the amounts of total bacteria as well as Fusobacterium nucleatum in tongue coating and dental plaque specimens obtained with and without tongue cleaning.MethodsWe conducted a randomized examiner-blind crossover study using 30 volunteers (average 23.7 ± 3.2 years old) without periodontitis. After dividing randomly into 2 groups, 1 group was instructed to clean the tongue, while the other did not. On days 1 (baseline), 3, and 10, tongue coating and dental plaque samples were collected after recording tongue coating score (Winkel tongue coating index: WTCI). After a washout period of 3 weeks, the same examinations were performed with the subjects allocated to the alternate group. Genomic DNA was purified from the samples and applied to SYBR® Green-based real-time PCR to quantify the amounts of total bacteria and F. nucleatum.ResultsAfter 3 days, the WTCI score recovered to baseline, though the amount of total bacteria in tongue coating was significantly lower as compared to the baseline. In plaque samples, the bacterial amounts on day 3 and 10 were significantly lower than the baseline with and without tongue cleaning. Principal component analysis showed that variations of bacterial amounts in the tongue coating and dental plaque samples were independent from each other. Furthermore, we found a strong association between amounts of total bacteria and F. nucleatum in specimens both.ConclusionsTongue cleaning reduced the amount of bacteria in tongue coating. However, the cleaning had no obvious contribution to inhibit dental plaque formation. Furthermore, recovery of the total bacterial amount induced an increase in F. nucleatum in both tongue coating and dental plaque. Thus, it is recommended that tongue cleaning and tooth brushing should both be performed for promoting oral health.

Relationship between oral status and prevalence of periodontopathic bacteria on the tongues of elderly individuals

Colonization of periodontopathic bacteria is associated with increased risk of systemic diseases. However, few studies have investigated the relationships between oral status factors and health-related quality of life (HR-QOL) and the prevalence of such bacteria in elderly individuals. This study investigated the prevalence of Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola and Tannerella forsythia in 165 community-dwelling functionally independent 85-year-old Japanese individuals (93 dentate, 72 edentulous) and the relationship to oral status, including oral malodour and HR-QOL. All four of the studied periodontopathic bacteria were found more frequently in tongue coating samples from dentate than edentulous subjects, and the prevalence of Porphyromonas gingivalis, Prevotella intermedia and Treponema denticola was significantly related to the number of teeth with a periodontal pocket depth ≥4 mm. These results suggest the existence of a stable circulation of periodontopathic bacteria between the gingival sulcus and tongue coating over time with teeth. In addition, the presence of teeth with a deep pocket and colonization of Treponema denticola were positively related to the level of CH(3)SH, whilst the number of present teeth contributed positively to HR-QOL, especially with regard to mental health. In conclusion, as the dentate state can retain colonization of periodontopathic pathogens in the oral cavity, both periodontal treatment and tongue care are important for maintaining a healthy oral status in the elderly, and possibly result in avoidance of risk for tooth loss and decline in HR-QOL, as well as protecting from systemic diseases.

Prediction of periodontopathic bacteria in dental plaque of periodontal healthy subjects by measurement of volatile sulfur compounds in mouth air

OBJECTIVES The aim of this study was to determine whether measurements of volatile sulfur compounds (VSCs) are useful to predict colonization of periodontopathic bacteria. For this purpose, we assessed the relationships among distributions of 4 species of periodontopathic bacteria in tongue coating and dental plaque, oral conditions including VSC concentration in mouth air, and smoking habit of periodontal healthy young subjects. METHODS The subjects were 108 young adults (mean age, 23.5±2.56 years) without clinical periodontal pockets. Information regarding smoking habit was obtained by interview. After VSC concentration in mouth, air was measured with a portable sulfide monitor (Halimeter(®)), non-stimulated saliva flow and dental caries status were assessed, and tongue coating and dental plaque samples were collected from the subjects. The tongue coating samples were weighed to determine the amount. The colonization of Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, and Treponema denticola in both tongue coating and plaque samples was investigated using species-specific polymerase chain reaction assays. RESULTS Significant relationships were observed between the colonization of periodontopathic bacteria in tongue coating and plaque samples, especially that of P. gingivalis. VSC concentration showed the most significant association with colonization of P. gingivalis in both tongue coating and dental plaque. Logistic regression analysis demonstrated that the adjusted partial correlation coefficient [Exp(B)] values for VSC concentration with the colonization of P. gingivalis, P. intermedia, and T. denticola in dental plaque were 135, 35.4 and 10.4, respectively. In addition, smoking habit was also shown to be a significant variable in regression models [Exp(B)=6.19, 8.92 and 2.53, respectively]. Therefore, receiver operating characteristic analysis was performed to predict the colonization of periodontal bacteria in dental plaque in the subjects divided by smoking habit. Based on our results, we found cut-off values that indicated likelihood ratios (LR) within the efficient range for positive findings in both groups. CONCLUSION The present results demonstrated that measurement of VSC concentration in mouth air is a useful method to predict the presence of colonization of some periodontopathic bacteria in dental plaque.

Targeting Individual Empowerment to Raise Leaders for Local Oral Health Promotion in Japan

The purpose of this study was to evaluate the characteristics of human resources for health promotion advocacy in a rural community. A 16-item questionnaire was sent to 1000 residents of a rural Japanese town. Items concerned demographics, participation in organizational activities, awareness of volunteer activities, and willingness to participate in community-based oral health activities. Responses were measured on a 5-point scale. The response rate was 57.4%. To reveal potential factors from the distribution of responses, a principal component analysis was performed, and 4 components were extracted. The components were interpreted as “Municipality initiative,” “Personal initiative,” “Worth volunteering,” and “Internal health locus of control (HLC),” respectively. The results of multiple regression analysis using the above components stratified by gender and age- group revealed that potential leaders in oral health activities in Japan are presently participating in social activities of their own accord and highly value volunteer activity. Target groups are senior males and middle-aged females.

The Effect of Eating Sea Cucumber Jelly on Candida Load in the Oral Cavity of Elderly Individuals in a Nursing Home

We conducted a double-blind randomized controlled study of elderly individuals in a nursing home to investigate the effect of the consumption of jelly containing sea cucumber on their oral Candida load. The jelly contained a hydrolysate of the sea cucumber Stichopus japonicus, which contained triterpene glycosides called holotoxins. The holotoxins worked as a fungicide, and their minimum inhibitory concentrations for Candida albicans were 7 µg/mL. Eight individuals in the nursing home took the sea cucumber jelly for a week and their oral Candida were counted before and after the intervention. Nine individuals took a control jelly without S. japonicus. The sea cucumber jelly showed inhibitory effects on the oral Candida. Thus, daily consumption of the S. japonicus jelly has the potential to reduce the oral Candida load in the elderly in nursing homes.