SummaryThe purpose of this study was to clarify which oral environmental factors affected number of microbes in saliva in an edentulous environment. We enrolled 68 edentulous subjects in the study. Numbers of total anaerobic bacteria and Candida species in saliva were determined. Age, sex, un-stimulated salivary flow rate, pH and viscosity of saliva, histatin level in saliva, tongue coating status, tongue pressure, denture plaque status, material of denture base, duration of edentulism, frequency of self oral health care and number of cigarettes per day were also investigated as oral environmental factors. Correlation between number of total anaerobic bacteria or Candida species and each oral environmental factor was determined with the Spearman rank correlation coefficient. Stepwise logistic-regression analysis was used to identify which factors were significantly associated with level of total anaerobic bacteria and Candida species. Correlation and stepwise logistic regression analyses revealed associations between un-stimulated salivary flow rate, tongue coating status, denture plaque status or frequency of self oral health care and number of total anaerobic bacteria.The correlation analysis showed a significant correlation between age and number of total anaerobic bacteria. Stepwise logistic analysis revealed associations between pH of saliva or viscosity of saliva and level of anaerobic bacteria; it also revealed 4 associations between histatin level in saliva or un-stimulated salivary flow rate and level of Candida species. We conclude that salivary flow rate, in particular, affects number of salivary microbes in an edentulous environment.

Colonisation of the oral cavity by periodontopathic bacteria in complete denture wearersObjective: The purpose of this study was to investigate colonisation by periodontopathic bacteria and the sites of colonisation in elderly upper and lower complete denture wearers. We also investigated the relationship between level of oral hygiene and colonisation by periodontopathic bacteria. Materials and methods: Forty edentulous and 37 dentate volunteers participated in this study. Samples were collected from whole saliva, and levels of Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia and Fusobacterium nucleatum were determined by PCR Invader technology. Detection of these species on oral mucosal and denture surfaces was performed by PCR. Fisher's exact test was used for the statistical analysis. Cluster analysis was employed to investigate trends in the periodontopathic bacteria flora in each sampling area. Results: Detection rates of periodontopathic bacteria in whole saliva were lower under edentulous conditions than under dentulous conditions, except for A. actinomycetemcomitans and F. nucleatum (p < 0.01). Detection rate of F. nucleatum was the highest in all areas. A positive correlation was observed between DNA quantification of P. gingivalis and number of Candida species in saliva. Cluster analysis of the test species identified two clusters. Tongue-coating status was associated with the detection rate of all periodontopathic bacteria investigated, and denture plaque status was associated with the detection rate of T. denticola and F. nucleatum. Conclusion: Results indicate the presence of periodontopathic bacteria under edentulous conditions and that the status of oral hygiene of the mucosal or denture surfaces affects colonisation by T. denticola and F. nucleatum.

Aim Previous studies on the association between intraoral conditions and mortality in community‐dwelling older individuals reported that fewer present teeth (PT) are significant risk factors for mortality. However, how the number of PT relative to the number of functional teeth (FT), including both present and rehabilitated teeth, influences mortality has not been investigated fully. This study examined the impact of the number of FT on mortality among community‐dwelling Japanese older adults. Methods This study was a retrospective, observational and population‐based follow‐up study, which examined 1188 older individuals who participated in an annual geriatric health examination from 2009 to 2015. The average follow‐up period was 1697.0 ± 774.5 days. The primary outcome was all‐cause mortality at follow‐up. The numbers of PT and FT of each participant were counted during an oral examination. In addition, demographics, clinical variables, blood nutrient markers, physical functions and perceived masticatory function were measured. Results Kaplan–Meier analysis, followed by a log‐rank test, revealed that fewer PT (P < 0.001) and FT (P = 0.002) were significantly associated with a reduced survival rate. Cox's proportional hazard analysis indicated that the number of FT, but not the number of PT, was a significant independent mortality risk factor after adjusting for demographics, clinical variables, nutrient markers and physical functioning (P = 0.036, hazard ratio: 2.089). Conclusions Current results suggest that the number of FT more strongly predicts all‐cause mortality than the number of PT among community‐dwelling older adults. Further studies are necessary to consider the confounding of socioeconomic status and disability status. Geriatr Gerontol Int 2020; ••: ••–••.

The most effective cleaning technique was the combination of a mouthwash and a moisturizing gel. Geriatr Gerontol Int 2017; 17: 116-121.

Purpose: Dental implant therapy is a common clinical treatment for missing teeth. However, the esthetic result is not as satisfactory as expected in some cases, especially in the anterior maxillary area. Poor esthetic results are caused by inadequate preparation of the hard and soft tissues in this area before treatment. The socket shield technique may be an alternative for a desirable esthetic outcome in dental implant treatments. Study selection: In the present systematic review, PubMed-Medline, Google Scholar, and ScienceDirect were searched for clinical studies published from January 2000 to December 2018. Results: Twenty studies were included, comprising one randomized controlled trial, two cohort studies, 14 clinical human case reports, and three retrospective case series. In total, 288 patients treated with the socket shield technique with immediate implant placement and follow-up between 3-60 months after placement were included. A quality assessment showed that 12 of the 20 included studies were of good quality. Twenty-six of the 274 (9.5%) cases developed complications or adverse effects related to the socket shield technique. Most studies reported implant survival without the complications (90.5%); most of the cases that were followed up for more than 12 months after implant placement achieved a good esthetic appearance. The failure rate was low without the complications, although there were some failures due to failed implant osseointegration, socket shield mobility and infection, socket shield exposure, socket shield migration, and apical root resorption. Conclusions: The socket shield technique can be used in dental implant treatment, but it remains difficult to predict the long-term success of this technique until high-quality evidence becomes available.