Risk Factors for Dementia Incidence Based on Previous Results of the Specific Health Checkups in Japan.

Dementia is a common disease in elderly people, with its prevalence expanding rapidly worldwide. Longitudinal and cohort studies on lifestyle and health conditions are needed to identify the risk of dementia. This study aimed to identify the risk factors for dementia incidence in Japan and to clarify the strategy for its primary care. In this study, an analysis was performed to investigate the association between the cognitive faculty level of the long-term care certification survey and the previous results of the specific health checkups in Japan. To investigate the risk factor for dementia incidence, a multivariable logistic regression analysis was performed, which showed a significant odds ratio for the incidence of dementia for two items, including abdominal circumference and insulin injections or oral hypoglycemic medications. The findings of our study suggested that a lower abdominal circumference had a higher risk for dementia incidence, and individuals who received insulin injections or oral hypoglycemic medications had a higher risk for dementia incidence based on the results of the health checkups conducted 10 years previously. Further, longer duration study with a larger sample is needed to identify the items from the specific health checkups that are associated with the risk of dementia.

Relationship between the Necessary Support Level for Oral Hygiene and Performance of Physical, Daily Activity, and Cognitive Functions.

To maintain good oral hygiene on their own, elderly adults need comprehensive abilities, such as physical, daily activity, and cognitive functions. In the long-term care certification, care support specialists conduct surveys that include a total of 74 items about physical function, daily activity function, living functions, cognitive function, mental/behavioral disorders, and adaption to social life. The data of the long-term care certification survey contain three items related to oral health: the necessary support level for oral hygiene, ability to swallow, and assistance with food intake. The aims of this study were to identify which functions are absent in elderly individuals who cannot maintain proper oral hygiene and to clarify at which stage it is necessary to assist elderly individuals with their oral hygiene and provide professional oral care. In this study, an analysis was conducted to identify the relationship between the necessary support level for oral hygiene and the performance of physical, daily activity, and cognitive functions. The results of the long-term care certification surveys were analyzed for 23,423 cases that involved 9,571 individuals who submitted a claim using long-term care statements between January 2009 and March 2018. The results of a multivariable logistic regression analysis showed that the following items had high odds ratios: "walk" and "stand up" in the physical and daily activity functions and the ability to "understand the everyday routine" and "make daily decisions" in the cognitive functions. The results of a decision tree analysis revealed that in order for elderly individuals to maintain good oral hygiene on their own, they must have adequate physical functioning as well as adequate performance of cognitive functions. Our study's findings suggest that comprehensive ability in both physical and cognitive functions is required for elderly adults to maintain their oral hygiene.

Salivary Levels of Hemoglobin for Screening Periodontal Disease: A Systematic Review.

Periodontal disease is a common inflammatory disease. It affects about 20-50% of global population in both developed and developing countries. Early detection of slight changes of periodontal tissue plays an important role in prevention of onset and progression of periodontal disease. Hence, there is a need of a screening test to assess periodontal tissue for health check-ups. Salivary levels hemoglobin (Hb) has been proposed to assess the conditions of the inflammation of gingiva. The aim of this systematic review was to evaluate and summarize critically the current evidences for Hb as periodontal screening test. We performed a literature search of report published using PubMed databases. A total of 55 articles were retrieved and 16 were selected. Our review focuses on corelation coefficient with periodontal clinical parameters or sensitivity and specificity. As a result, fourteen studies calculated sensitivity and specificity of Hb. Six studies measured salivary levels hemoglobin at laboratory: three studies used polyclonal antibody reactions and other studies used colorimetric tests. Eight studies used paper strip method: 4 studies used monoclonal antibody reaction and 4 studies used colorimetric tests. Youden's indexes by antibody reaction were better than those of colorimetric methods. Evidences are described above and further studies are necessary to set the cut off values stratified by gender, age and number of remaining teeth.

Therapeutic effects of isoflavones on impaired salivary secretion.

Dry mouth, which is characterized by decreased salivation, has a number of causes; the involvement of estrogen has been suggested as symptoms typically develop in middle-aged females. However, there is a lack of consensus regarding the treatment of this condition. Soy isoflavones, a subgroup of flavonoids, are abundantly found in the soy germ. They are thought to exert a number of effects by specifically binding to estrogen receptors due to their structural similarity to estrogen. Recently, soy isoflavones have been found to exert antioxidant effects, ameliorating disorders caused by reactive oxygen/free radicals. Based on these observations, the effects of soybean isoflavones on impaired salivary secretion were studied in patients with dry mouth. Soy isoflavone aglycones were administered at 25 mg per day to 15 subjects with an average age of 67.9 ± 8.0 years for 2 months, and salivary secretion was analyzed. The results showed a significant improvement based on the saliva flow rate and self-completed questionnaire, thus suggesting the usefulness of isoflavones in improving the symptoms of salivary gland hypofunction.

Possible benefits of singing to the mental and physical condition of the elderly.

BACKGROUND: The evaluation and management of stress are important for the prevention of both depression and cardiovascular disease. In addition, the maintenance of the oral condition of the elderly is essential to enable them to stay healthy, especially to prevent aspiration pneumonia and improve mental health in an aging society. Therefore, we examined the efficacy of singing on the oral condition, mental health status, and immunity of the elderly to determine if singing could contribute to the improvement of their physical condition. METHODS: Forty-four subjects (10 men, 34 women), aged 60 years or older, participated in this study. The efficacy of singing on mental health status and immunocompetence was examined by swallowing function, oral condition, blood, and saliva tests, as well as through questionnaires taken before and after singing. RESULTS: The results showed that the amount of saliva increased and the level of cortisol, a salivary stress marker, decreased after singing. The Visual Analog Scale (VAS) scores for feeling refreshed, comfortable, pleasurable, light-hearted, relieved, and relaxed; the tension and confusion subscale score; and the total mood disturbance (TMD) score of the Profile of Mood States (POMS) all showed improvements. Furthermore, the same tendencies were shown regardless of whether or not the subjects liked singing. CONCLUSIONS: Our results suggest that singing can be effective in improving the mental health and oral condition of the elderly.

Correlation of dental health behavior with health awareness and subjective symptoms in a rural population in Japan.

The aim of this study was to determine the association of dental health behavior with health awareness, oral condition, and subjective symptoms in Japan. The present study included 1699 individuals who underwent dental checkups at the public health center of Miura City. All those who underwent dental checkups were asked to fill out a questionnaire. The correlation between having a regular dentist and each of the other items was analyzed. Undergoing regular checkups was significantly related to having a regular dentist. To analyze the correlation of dental health behavior with Subjective symptoms and Health awareness, structured equation modeling was performed following factor analysis. As a result, only the regression weight between dental health behavior and health awareness was found to be statistically significant. The present survey indicates that dental health behavior was significantly related to Health awareness but not to Subjective symptoms.

Risk factors with intravenous sedation for patients with disabilities.

The purpose of this study was to identify the risk factors associated with low peripheral oxygen saturation (SpO2) and delayed recovery of dental patients with disabilities after intravenous sedation. A total of 1213 patients with disabilities were retrospectively investigated with respect to demographic parameters and sedation conditions. Multivariate logistic analyses were conducted for patients with an SpO2 <90% and a recovery period of >60 minutes to identify the risk factors for poor sedation conditions. A significant odds ratio related to decreased SpO2 was observed for age, sex, midazolam and propofol levels, concurrent use of nitrous oxide, cerebral palsy, Down syndrome, and mental retardation. The most problematic patients were those diagnosed with Down syndrome (odds ratio, 3.003-7.978; 95% confidence interval; P < .001). Decision tree analysis showed an increased risk of decreased SpO2 in males with Down syndrome or after administration of >0.493 mg/kg propofol in combination with midazolam. An increased risk of delayed awakening was seen in patients aged less than 21 years and in males administered >0.032 mg/kg of midazolam. Intravenous sedation for dental patients with disabilities, particularly those with cerebral palsy, Down syndrome, or mental retardation, increases the risk of decreased SpO2. In addition, delayed recovery is expected after midazolam administration.

Effects of coenzyme Q10 on salivary secretion.

OBJECTIVES: Dry mouth is a condition associated with reduced salivary secretion and is thought to be related to aging. This study was conducted to test whether reduced (ubiquinol) or oxidized (ubiquinone) forms of CoQ10 affect salivary secretion and salivary CoQ10 content before and after treatment. DESIGN AND METHODS: Sixty-six patients were given either ubiquinol or ubiquinone orally at a dosage of 100 mg/day, or a placebo for 1 month, and salivary secretion and salivary CoQ10 content were analyzed before and after treatment. RESULTS: Both parameters were significantly improved following treatment with either form of CoQ10, suggesting the effectiveness of CoQ10 in attenuating dry mouth symptoms. CONCLUSION: CoQ10 was locally detected in salivary glands, suggesting that orally administered CoQ10 was transported to the salivary glands via the blood stream and exerted its activity, improving salivary secretion.

Evaluation of therapeutic effects of astaxanthin on impairments in salivary secretion.

The involvement of reactive oxygen species (ROS) in the pathophysiology of Sjögren's syndrome (SS), an autoimmune disorder, and irradiation-induced impairments in salivary secretion has been reported. Meanwhile, the strong antioxidant astaxanthin (Ast) has been suggested to have therapeutic effects on various diseases. In the present study, we examined the ROS scavenging capacity of Ast using a human salivary gland epithelial cell line (HSY) and investigated the effects of Ast on salivary secretion in a mouse model of irradiation-induced salivary gland dysfunction. Furthermore, we performed a clinical study of Ast in six SS patients and six normal individuals, quantifying the volume of saliva secretion and the level of oxidative stress markers in the saliva. Ast partially suppressed hydrogen peroxide-induced ROS in HSY cells. The mouse model demonstrated that the pre-administration of Ast resulted in the suppression of irradiation-induced hyposalivation. Furthermore, the administration of Ast appeared to increase salivary output in both the SS and normal groups. The level of oxidative stress marker, hexanoyl-lysine, in the saliva was reduced after Ast intake. These results suggest that Ast might act as an ROS scavenger, providing benefits to SS patients with impaired salivary secretion.

Bonding durability against water of a fluorine-containing resin for precious metal alloys.

In order to clarify the effect of fluorination of an adhesive resin on the durability of the resin bond to precious metal alloys, 2,2,2-trifluoroethyl methacrylate (TFEMA)-poly(2,2,2-trifluoroethyl methacrylate) (PTFEMA)/TBBO adhesive resin was prepared. The tensile bond strength of this resin to precious metal alloys treated with 9,10-epithiodecyl methacrylate (EP8MA) generally increased in the order Ag alloy

Immunogenicity and growth inhibitory efficacy of the prime-boost immunization regime with DNA followed by recombinant vaccinia virus carrying the P29 gene of Babesia gibsoni in dogs.

In recent studies, heterologous prime-boost approaches, employing plasmid DNA and viral vector pathogen-delivering sequences, have been considered an effective protection strategy for intracellular parasite infections. Here, we evaluated the efficacy of such a strategy against the canine Babesia gibsoni infection. The DNA (pCAGGS-P29) and recombinant vaccinia virus (vvP29) both encoding the P29 of B. gibsoni were used in this study. The dogs were immunized 3 times with priming DNA and boosted once with recombinant virus. The dogs immunized with P29 developed a significant level of IgG2 antibody against P29. The response was strongly boosted by the inoculation of vvP29. The peripheral IFN-gamma responses of the dogs immunized with P29 were significantly higher than those of controls after the parasite inoculation. Moreover, the P29 immunized group showed a significantly low level of parasitemia. In conclusion, this study supports the efficacy of a prime-boost strategy for dogs against canine B. gibsoni infection.

Construction of a dental caries prediction model by data mining.

Recently, the distribution of dental caries has been shown to be skewed, and precise prediction models cannot be obtained using all the data. We applied a balancing technique to obtain more appropriate and robust models, and compared their accuracy with that of the conventional model. The data were obtained from annual oral check-ups for schoolchildren conducted in Japan. Five hundred children were followed from ages 5 to 8, and the three-year follow-up data were used. The variables used were salivary levels of mutans streptococci and lactobacilli, 3-min stimulated saliva volume, salivary pH, fluoride usage, and frequency of consumption of sweet snacks and beverages. Initially, conventional models were constructed by logistic regression analysis, neural network (a kind of prediction method), and decision analysis. Next, the balancing technique was used. To construct new models, we randomly sampled the same number of subjects with and without new dental caries. By repeated sampling, 10 models were constructed for each method. Application of the balancing technique resulted in the most robust model, with 0.73 sensitivity and 0.77 specificity obtained by C 5.0 analysis. For data with a skewed distribution, the balancing method could be one of the important techniques for obtaining a suitable and robust prediction model for dental caries.

Water durability of resin bond to pure gold treated with various adhesion promoting thiirane monomers.

Adhesion promoting monomers for precious metals, 2,3-epithiopropyl methacrylate (EP1MA), 4,5-epithiopentyl methacrylate (EP3MA), 9,10-epithiodecyl methacrylate (EP8MA), 10,11-epithioundecyl methacrylate (EP9MA), 9,10-epithiodecyl 4-vinylbenzoate (EP8VB), 2,3-epithiocyclohexyl methacrylate (EPCHMA), and 3,4-epithiobutyl 2,2-bis(methacryloyloxymethyl)-propionate (EP2BMA), were used as surface treatment agents for pure gold to improve the durability of resin bonds against water. Treated specimens were butt-jointed together with MMA-PMMA resins, and tensile bond strength was measured after 2,000 thermal cycles in water. Bond strength to precious metal alloys was also determined under the same condition to clarify the influence of metal composition. The adhesion performance of thiirane monomers to pure gold highly depended on their chemical structure. EP3MA, EP8MA, EP9MA, EP8VB, and EP2BMA showed excellent performance, while EP1MA exhibited a moderate one and EPCHMA a poor one. The comparison of pure gold with precious metal alloys revealed the usefulness of pure gold as a standard, common adherend for bond strength evaluations.

Validity and reliability of patient satisfaction questionnaires in a dental school in Japan.

PURPOSE: The purpose of this study was to construct questionnaires for the dental school setting from freely given patient answers with the aid of text mining, and to confirm the structure, reliability and validity of the questionnaires. METHODS: Using these questionnaires, we carried out a survey of the satisfaction of patients treated at the Dental Hospital of the Tsurumi University School of Dental Medicine. A total of 3394 patients participated in the study. To confirm the reliability of inter-item correlations and construct validity, factor analysis was carried out, and items belonging to each factor and Cronbach's alpha coefficients were calculated. RESULTS: Four factors were extracted and 64.0% of the variance was explained by these four factors. All correlation coefficients were >0.85. These four factors were: 'Treatment', 'Communication', 'Facilities' and 'Appearances'. From structural equation modelling, we determined that overall satisfaction was >0.75 and was statistically significant. CONCLUSION: The questionnaires used in this study are useful for measuring patient satisfaction in the dental school hospital setting.

Prime-boost immunization with DNA followed by a recombinant vaccinia virus expressing P50 induced protective immunity against Babesia gibsoni infection in dogs.

A heterologous prime-boost immunization regime with priming DNA followed by recombinant vaccinia virus expressing relevant antigens has been shown to induce effective immune responses against several infectious pathogens. In this study, we constructed a recombinant plasmid and vaccinia virus, both of which expressed P50 of Babesia gibsoni, to investigate the immunogenicity and protective efficacy of a heterologous prime-boost immunization against canine babesiosis. The dogs immunized with the prime-boost regime developed a significantly high level of specific antibody against P50 when compared with the control groups, and the antibody level was strongly increased after a booster immunization with a recombinant vaccinia virus. The prime-boost immunization regime induced a specific IgG2 antibody response and IFN-gamma production in dogs. Two weeks after the booster immunization with a recombinant vaccinia virus expressing P50, the dogs were challenged with B. gibsoni patasites. The dogs immunized with the prime-boost regime showed partial protection, manifested as a significantly low level of parasitemia and a 2-day delay of the peak parasitemia. These results indicated that such a heterologous prime-boost immunization approach might be useful against B. gibsoni infection in dogs.

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 of cariogenic bacteria and dental caries in adults.

Many studies suggest that mutans streptococci (MS), Lactobacillus (LB), and salivary buffering capacity are important risk factors for dental caries. However, target populations for most studies were children. In adult patients, the same risk factors affect the number of fillings or prostheses or secondary caries. It is therefore important to investigate these risk factors as predictors of caries in adults. In the present study, we evaluated the oral conditions of adult subjects at private dental offices using bite-wing radiographs. Detection of salivary LB level using Dentocult LB had a statistically significant correlation with the number of flat surface caries and approximal caries (P < 0.001). Detection of salivary MS level using Dentocult MS and salivary buffering capacity did not predict dental caries. Thus, detection of salivary LB level using Dentocult LB may be a useful tool for detecting approximal and secondary caries.

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.