An in vitro study of the effects of Phellodendron bark extract and berberine chloride on periodontal pathogenic bacteria in the oral microbiome.

OBJECTIVES: Periodontal disease is triggered by oral microbiome dysbiosis. Thus, to prevent its onset, it is important to maintain relative abundance of periodontal pathogenic bacteria in the oral microbiome at a low level. While Phellodendron bark extract (PBE) and its active ingredient, berberine, exert antibacterial effects on periodontal pathogenic bacteria, such as Porphyromonas gingivalis, their effects on the oral microbiome as a whole remain unknown. Therefore, we aimed to clarify the potential of PBE and berberine chloride (BC) in regulating the relative abundance of periodontal pathogenic bacteria in the oral microbiome. METHODS: Saliva was collected from 20 participants. Each participant's saliva was combined separately with P. gingivalis suspension and either PBE or BC in a modified basal medium. The samples were then incubated under anaerobic conditions for 24 h. After cultivation, we determined the total bacterial concentration using quantitative polymerase chain reaction analysis and the bacterial composition using 16 S ribosomal RNA gene sequencing. RESULTS: The total bacterial concentration was reduced because of treatment with PBE and BC. Bacterial 16 S ribosomal RNA gene sequencing confirmed that treatment with PBE and BC significantly reduced the relative abundance of periodontal pathogenic bacteria, including red and orange complex bacteria. CONCLUSIONS: Our findings suggest that PBE and BC reduce the relative abundance of periodontal pathogenic bacteria in the oral microbiome. Thus, PBE and BC can aid in preventing periodontal disease, given their ability to regulate the oral microbiome composition and their anti-inflammatory effects.

Comparison of oral microbiome profiles in 18-month-old infants and their parents.

The onset and progress of dental caries and periodontal disease is associated with the oral microbiome. Therefore, it is important to understand the factors that influence oral microbiome formation. One of the factors that influence oral microbiome formation is the transmission of oral bacteria from parents. However, it remains unclear when the transmission begins, and the difference in contributions of father and mother. Here, we focused on the oral microbiome of 18-month-old infants, at which age deciduous dentition is formed and the oral microbiome is likely to become stable, with that of their parents. We collected saliva from forty 18-month-old infants and their parents and compared the diversity and composition of the microbiome using next-generation sequencing of 16S rRNA genes. The results showed that microbial diversity in infants was significantly lower than that in parents and composition of microbiome were significantly different between infants and parents. Meanwhile, the microbiome of the infants was more similar to that of their mothers than unrelated adults. The bacteria highly shared between infants and parents included not only commensal bacteria but also disease related bacteria. These results suggested that the oral microbiome of the parents influences that of their children aged < 18 months.

Cross-cultural validity of a dietary questionnaire for studies of dental caries risk in Japanese.

BACKGROUND: Diet is a major modifiable contributing factor in the etiology of dental caries. The purpose of this paper is to examine the reliability and cross-cultural validity of the Japanese version of the Food Frequency Questionnaire to assess dietary intake in relation to dental caries risk in Japanese. METHODS: The 38-item Food Frequency Questionnaire, in which Japanese food items were added to increase content validity, was translated into Japanese, and administered to two samples. The first sample comprised 355 pregnant women with mean age of 29.2 ± 4.2 years for the internal consistency and criterion validity analyses. Factor analysis (principal components with Varimax rotation) was used to determine dimensionality. The dietary cariogenicity score was calculated from the Food Frequency Questionnaire and used for the analyses. Salivary mutans streptococci level was used as a semi-quantitative assessment of dental caries risk and measured by Dentocult SM. Dentocult SM scores were compared with the dietary cariogenicity score computed from the Food Frequency Questionnaire to examine criterion validity, and assessed by Spearman's correlation coefficient (rs) and Kruskal-Wallis test. Test-retest reliability of the Food Frequency Questionnaire was assessed with a second sample of 25 adults with mean age of 34.0 ± 3.0 years by using the intraclass correlation coefficient analysis. RESULTS: The Japanese language version of the Food Frequency Questionnaire showed high test-retest reliability (ICC = 0.70) and good criterion validity assessed by relationship with salivary mutans streptococci levels (rs = 0.22; p < 0.001). Factor analysis revealed four subscales that construct the questionnaire (solid sugars, solid and starchy sugars, liquid and semisolid sugars, sticky and slowly dissolving sugars). Internal consistency were low to acceptable (Cronbach's alpha = 0.67 for the total scale, 0.46-0.61 for each subscale). Mean dietary cariogenicity scores were 50.8 ± 19.5 in the first sample, 47.4 ± 14.1, and 40.6 ± 11.3 for the first and second administrations in the second sample. The distribution of Dentocult SM score was 6.8% (score = 0), 34.4% (score = 1), 39.4% (score = 2), and 19.4% (score = 3). Participants with higher scores were more likely to have higher dietary cariogenicity scores (p < 0.001; Kruskal-Wallis test). CONCLUSIONS: These results provide the preliminary evidence for the reliability and validity of the Japanese language Food Frequency Questionnaire.

Evaluation of the Total Design Method in a survey of Japanese dentists.

BACKGROUND: This study assessed the application of the Total Design Method (TDM) in a mail survey of Japanese dentists. The TDM was chosen because survey response rates in Japan are unacceptably low and the TDM had previously been used in a general population survey. METHODS: Four hundred and seventy eight dentist members of the Okayama Medical and Dental Practitioner's Association were surveyed. The nine-page, 27-item questionnaire covered dentist job satisfaction, physical practice, and dentist and patient characteristics. Respondents to the first mailing or the one-week follow-up postcard were defined as early responders; others who responded were late responders. Responder bias was assessed by examining age, gender and training. RESULTS: The overall response rate was 46.7% (223/478). The response rates by follow-up mailing were, 18% after the first mailing, 35.4% after the follow-up postcard, 42.3% after the second mailing, and 46.7% after the third mailing. Respondents did not differ from non-respondents in age or gender, nor were there differences between early and late responders. CONCLUSION: The application of TDM in this survey of Japanese dentists produced lower rates of response than expected from previous Japanese and US studies.

The Children's Fear Survey Schedule-Dental Subscale in Japan.

OBJECTIVES: The aims of this research are to examine the reliability and validity of the Japanese version of the Dental Subscale of Children's Fear Survey Schedule (CFSS-DS), and to examine the responses of children in the dental setting and in the community. METHODS: The CFSS-DS was translated into Japanese and administered to three samples. The first sample comprised 134 child patients aged 8-15 years, of whom 100 were assigned for test-retest analysis, and the behavior of the remaining 34 additional children were rated during their dental appointments, and compared with their questionnaire results. A second sample of 532 child patients aged 8-15 years, completed the CFSS-DS and also one additional item measuring fear of returning to the dentist. A third sample of 1250 school children aged 8-15 years was surveyed using the CFSS-DS and the additional item measuring fear of returning to the dentist. RESULTS: The Japanese version of the CFSS-DS showed good internal consistency (alpha=0.91) and test-retest reliability (r=0.90), as well as good criterion validity assessed by the relationship with actual child behavior (r(s)=0.51). It also showed good construct validity assessed by correlation with willingness to return to the dentist. Fear levels were higher in the school sample than in the clinic sample (27.7 versus 24.6). Girls reported more fear than boys (26.2 versus 23.2 in the clinic sample, and 30.7 versus 24.8 in the school sample). Injections, choking, having a stranger touch them, and drilling were the most common fears. Factor analyses demonstrated a factor pattern similar to the results found in other cultures. CONCLUSION: The results suggest that the CFSS-DS is reliable and valid and operates in Japan as it does in other cultures.

Oral manifestations of cyclic neutropenia in a Japanese child: case report with a 5-year follow-up.

Cyclic neutropenia is an uncommon hematologic disorder characterized by a marked decrease in the number of neutrophils in the peripheral blood occurring at regular intervals. The neutropenic phase is characteristically associated with clinical symptoms such as recurrent fever, malaise, headaches, anorexia, pharyngitis, ulcers of the oral mucous membrane, and gingival inflammation. This case report describes a Japanese girl who has this disease and suffers from periodontitis and oral ulceration. Her case has been followed up for the past 5 years from age 7 to 12. The importance of regular oral hygiene, careful removal of subgingival plaque and calculus, and periodic and thorough professional mechanical tooth cleaning was emphasized to arrest the progress of periodontal breakdown. Local antibiotic application with minocycline ointment in periodontal pockets was beneficial as an ancillary treatment, especially during neutropenic periods.