Denture Wearing Moderates the Association between Aspiration Risk and Incident Pneumonia in Older Nursing Home Residents: A Prospective Cohort Study

Reduced number of teeth with and without dental prostheses and low frequency of laughter in older adults: Mediation by poor oral function

PURPOSE

Laughter is expected to have health-protective effects, but the potential link between tooth loss and laughter remains unclear. Therefore, this study aimed to examine the association between tooth loss and a low frequency of laughter among older adults in Japan, to elucidate whether this association could be mitigated by dental prostheses, and to evaluate the magnitude of the association mediated by poor oral function.

METHODS

We used cross-sectional data from 157,708 functionally independent participants aged ≥65 years (46.3% male) from the Japan Gerontological Evaluation Study. A modified Poisson regression model was applied to examine the association between the number of remaining teeth (≥20/10-19/0-9), dental prostheses use, and infrequent laughter (i.e., laughing never or almost never). Causal mediation analysis was performed to assess whether the association was mediated by difficulties in eating hard foods, choking, or dry mouth.

RESULTS

Among the participants, 9,129 reported infrequent laughter. Participants with ≤9 and 10-19 teeth who did not use dental prostheses had a 1.29 and 1.14 times higher likelihood of infrequent laughter than those with ≥20 teeth, respectively. Furthermore, difficulty eating hard foods, choking, and dry mouth mediated 22.8%, 0.4%, and 4.3% of the association between fewer remaining teeth and infrequent laughter, respectively. Meanwhile, we did not find evidence for the differences in infrequent laughter between participants with ≤19 teeth using dental prostheses and those with ≥20 teeth.

CONCLUSIONS

Tooth loss among individuals without dental prostheses was associated with infrequent laughter, and this association was mediated by poor oral function.

A comparison of the prevalence of respiratory pathogens and opportunistic respiratory pathogenic profile of 'clean' and 'unclean' removable dental prostheses

OBJECTIVES

To determine and compare the opportunistic respiratory pathogenic index (ORPI) and prevalence of respiratory pathogens between clean and unclean removable prostheses.

METHODS

A cross-sectional study was conducted among 97 removable prosthesis wearers at a teaching dental hospital. Participants' prosthesis hygiene was grouped into clean and unclean. After prosthesis plaque samples were sequenced using the Type IIB Restriction-site Associated DNA Sequencing for Microbiome method, the prevalence was assessed for the presence of respiratory pathogens on each sample. The ORPIs for clean and unclean prostheses were quantified based on the sum of the relative abundance of respiratory pathogenic bacteria in a microbiome using a reference database that contains opportunistic respiratory pathogens and disease-associated information.

RESULTS

A total of 30 opportunistic respiratory pathogens were identified on the removable prostheses. Eighty-one (83.5 %) removable prostheses harboured respiratory pathogenic bacteria. Stenotrophomonas maltophilia (34.0 %), Pseudomonas aeruginosa (27.8 %), and Streptococcus agalactiae (27.8 %) were the top three prevalent respiratory pathogens detected in plaque samples. There was a significantly higher prevalence of respiratory pathogens residing on unclean than clean prostheses (P = 0.046). However, the ORPIs in both groups showed no statistically significant difference (P = 0.516).

CONCLUSIONS

The ORPIs for both clean and unclean prostheses demonstrated a similar abundance of respiratory pathogens. However, the high prevalence of respiratory pathogens residing on unclean prostheses should not be underestimated. Therefore, maintaining good prosthesis hygiene is still important for overall oral and systemic health, even though the direct link between prosthesis cleanliness and reduced abundance of respiratory pathogens has not been established.

CLINICAL SIGNIFICANCE

The association between the prevalence of respiratory pathogens and unclean removable prostheses has been demonstrated and might increase the theoretical risk of respiratory disease development.

Association between denture use and food form in older adults requiring long-term care: A multicenter cross-sectional study

PURPOSE

This study aimed to determine whether denture use contributes to maintaining and improving food forms in long-term care facility (LTCFs) residents.

METHODS

In 888 residents of 37 LTCFs in Japan, the following were investigated: nutritional intake status, food forms, age, sex, Barthel index (BI), clinical dementia rating (CDR), number of teeth present, number of occlusal supports, swallowing function, and use of dentures. Among all residents, those who were well-nourished and had ≤9 occlusal supports were analyzed. Based on standardized criteria, the food forms consumed by the subjects were divided into two groups: dysphagia and normal diet, which were further classified into four levels. Analysis was performed using a generalized estimation equation with the four levels of food forms as dependent variables and age, sex, BI, CDR, presence of dysphagia, number of teeth present, and use of dentures as independent variables.

RESULTS

The final analysis included 622 (70.0%) residents. Of these, 380 (61.1%) used dentures. The analyses revealed that food form was significantly associated with age (adjusted odds ratio [OR], 0.98), BI (OR, 1.04), number of teeth present (OR, 1.03), presence of dysphagia (OR, 0.44), and use of dentures (OR, 2.82).

CONCLUSION

Denture use was associated with food forms among Japanese LTCF residents. This indicates that the use of dentures is related to the maintenance of food forms, even in the elderly who participate in few activities of daily living, have reduced cognitive function, and require long-term care.

The denture microbiome in health and disease: an exploration of a unique community

The United Nations suggests the global population of denture wearers (an artificial device that acts as a replacement for teeth) is likely to rise significantly by the year 2050. Dentures become colonized by microbial biofilms, the composition of which is influenced by complex factors such as patient’s age and health, and the nature of the denture material. Since colonization (and subsequent biofilm formation) by some micro‐organisms can significantly impact the health of the denture wearer, the study of denture microbiology has long been of interest to researchers. The specific local and systemic health risks of denture plaque are different from those of dental plaque, particularly with respect to the presence of the opportunist pathogen Candida albicans and various other nonoral opportunists. Here, we reflect on advancements in our understanding of the relationship between micro‐organisms, dentures, and the host, and highlight how our growing knowledge of the microbiome, biofilms, and novel antimicrobial technologies may better inform diagnosis, treatment, and prevention of denture‐associated infections, thereby enhancing the quality and longevity of denture wearers.

Dental Students' Awareness After Clinical Training Between Dental Treatment and Systemic Health: A Questionnaire-Based Survey

Clinical training is an essential program for dental students to learn clinical skills. The aim of this study was to survey whether dental students who had undergone clinical training understood the clinical significance of dental treatment and its connection to systemic health. An awareness survey was conducted in dentistry students both before and after undergraduate clinical training. A total of 42 dental students were recruited before clinical training, and 32 dental students responded to the survey. In addition, all of the 42 dental students responded to the survey after clinical training. A total of 53 medical students were recruited as control subjects. Differences between the 2 groups were analyzed using Fisher's exact test. Before clinical training, a higher percentage of dental students felt the positive effects of periodontal treatment on systemic health. A higher percentage of dental students also recognized the positive effects of prosthetic treatment on geriatric conditions. After clinical training, no significant differences were found between periodontal and prosthetic treatment when surveyed about the positive effects of dental treatment on geriatric conditions. Undergraduate clinical training is essential for improving the students' understanding of the clinical significance of dental treatment. These surveys suggest that dental education supported by clinical experience contributes to understand the role of dental treatment.

Risk Factors for Aspiration Pneumonia among Elderly Patients in a Community-Based Integrated Care Unit: A Retrospective Cohort Study

We aimed to clarify the physical factors associated with the incidence of aspiration pneumonia in a community-based integrated care unit. This retrospective cohort study included 412 patients aged 65 years or older admitted to a community-based integrated care unit. A new diagnosis of aspiration pneumonia made by the attending physician based on physical examination, imaging findings, and blood test data after 48 h of admission was considered as an incidence of aspiration pneumonia. Basic patient information, activities of daily living, swallowing function, nutritional status, cognitive function, oral health-related factors, and energy intake were retrospectively investigated. We classified the patients into a pneumonia group and a non-pneumonia group, and examined the factors associated with the development of aspiration pneumonia. The mean age was 86.9 ± 8.1 years, and the pneumonia group comprised 49 participants. Comparison between the groups showed significant differences in oral environment, denture use, cognitive functional independence measure, and discharge to home. In multivariate logistic regression analysis, oral environment (odds ratio (OR) = 0.229, 95% confidence interval (CI): 0.070–0.753, p = 0.015) and use of dentures (OR = 0.360, 95% CI: 0.172–0.754, p = 0.007) were independently associated with aspiration pneumonia. Oral care and the use of dentures may be effective in preventing aspiration pneumonia.

Correlation between the relative abundance of oral bacteria and Candida albicans in denture and dental plaques

OBJECTIVES

The opportunistic fungus Candida albicans is a component of denture plaque and is associated with denture-related stomatitis. Inter-kingdom interactions between C. albicans and bacteria exist in such multi-species biofilms, which may affect the microbial composition of the plaque. This study was performed to investigate the bacterial composition of denture plaques, and the correlation between the relative abundance of these bacteria and C. albicans.

METHODS

Thirty denture plaque and 16 dental plaque samples were collected from 18 denture wearers (mean age, 80.3 years). After DNA extraction, a meta 16S rDNA amplicon library was constructed using PCR primers targeting the V3-V4 hypervariable region of bacteria. The amplicon was evaluated by high-throughput sequencing, followed by bacterial population analysis. The concentrations of both C. albicans DNA and total bacterial DNA were determined by real-time PCR. The correlation between the relative abundance of each bacterial genus and C. albicans was analyzed through Spearman's rank correlation.

RESULTS

The genera Streptococcus, Lactobacillus, Rothia, and Corynebacterium were found to be more abundant in dentures than in dental plaques. The predominant bacteria in healthcare-associated pneumonia also inhabited denture surfaces. C. albicans was positively correlated with three acidogenic bacteria and negatively correlated with Leptotrichia and pathogens associated with periodontitis and endocarditis.

CONCLUSIONS

Dentures may be significant reservoirs of pathogens causing aspiration pneumonia. Bacteria showing negative correlation with C. albicans, such as Leptotrichia, may be useful for controlling the growth of C. albicans in antifungal therapies.

Oral healthcare delivery in institutionalised older people: A health-economic evaluation

OBJECTIVES

This health-economic evaluation aimed to assess the cost-effectiveness of a number of alternatives for preventive and curative oral health care in institutionalised older people in Flanders.

METHODS

A six-state Markov model was used to compare expected costs and healthy oral years (HOYs) of four alternatives: (1) usual care; (2) on-site preventive care; (3) on-site preventive care + curative care in the community; and (4) on-site preventive care + on-site curative care. A healthcare payer perspective was adopted, and the time horizon was 10 years. Deterministic and probabilistic sensitivity analyses were performed.

RESULTS

Incremental cost-effectiveness ratios (ICERs) of alternatives 2, 3 and 4 (all compared to alternative 1) were as follows: (2) 7944 €/HOY gained; (3) 1576 €/HOY gained; and (4) 1132 €/HOY gained. Hence, alternatives 2 and 3 were not cost-effective compared to alternative 4. The probability that oral care interventions are more effective and cost-saving than usual care was <3% for all three interventions.

CONCLUSIONS

For institutionalised older people, on-site solutions for preventive and curative oral health care might be the most cost-effective alternative. It should be kept in mind that on-site solutions require large initial investment and that the advanced age of the population and the high costs of oral health care make it unlikely that these interventions would become cost-saving, even in the long term.

Antibacterial and Antifungal Activities of PMMAs Implanted Fluorine and/or Silver Ions by Plasma-Based Ion Implantation with Argon

The purpose of this study was to examine the anti-oral microorganism effects of fluorine and/or silver ions implanted into acrylic resin (PMMA) using plasma-based ion implantation (PBII) with argon gas. The experimental PMMA specimens were implanted with F and Ag ions alone or simultaneously by the PBII method using Ar or Ar/F₂ gases and Ag mesh. The surface characteristics were evaluated by X-ray photoelectron spectroscopy (XPS), contact angle measurements, and atomic force microscopy (AFM). Moreover, the antibacterial activity against Streptococcus mutans (S. mutans) and the antifungal activity against Candida albicans (C. albicans) were examined by the adenosine-5'-triphosphate (ATP) emission luminescence method. XPS spectra of the modified specimens revealed peaks due to F in the Ar/F and the Ar/F+Ag groups, and due to Ag in the Ar+Ag and the Ar/F+Ag groups. The water contact angle increased significantly due to the implantation of Ar, F, and Ag. In the AFM observations, the surface roughness of the Ar/F and the Ar/F+Ag groups increased significantly by less than 5 nanometers. The presence of F and Ag was found to inhibit S. mutans growth in the Ar+Ag and the Ar/F+Ag groups. However, this method provided no significant antifungal activity against C. albicans.