Oral Health Status of Workers in Acid Exposure Environments in Japan: A Cross-sectional Study.

Although the working environment may play a role in dental acid erosion, few studies have been conducted on this in Japanese workers in recent years. The purpose of this study was to investigate oral health status, including dental erosion, in workers who may have been exposed to an acidic environment. The study participants were recruited by an online research company. Oral examinations and questionnaire surveys were conducted on this cohort in January 2023. A total of 144 participants were finally included. Workers exposed to an acidic environment showed more use of protective equipment and underwent more dental examinations at the workplace (p<0.001). Possible dental erosion was observed in only 3 out of the total of 144 participants (2.1%), however. No significant difference was observed in the number of teeth, caries experience, or dental erosion according to the number of years of acid exposure in the workplace. The results of this study suggest that acid exposure exerts a relatively small effect on the oral health status of workers in Japan.

Body mass index and lung cancer risk: Pooled analysis of 10 prospective cohort studies in Japan.

Mounting evidence suggests that body mass index (BMI) is inversely associated with the risk of lung cancer. However, relatively few studies have explored this association in Asian people, who have a much lower prevalence of obesity than Caucasians. We pooled data from 10 prospective cohort studies involving 444,143 Japanese men and women to address the association between BMI and the risk of lung cancer. Study-specific hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated in each cohort using the Cox proportional hazards model. A meta-analysis was undertaken by combining the results from each cohort. Heterogeneity across studies was evaluated using Cochran's Q and I2statistics. During 5,730,013 person-years of follow-up, 6454 incident lung cancer cases (4727 men and 1727 women) were identified. Baseline BMI was inversely associated with lung cancer risk in men and women combined. While leanness (BMI <18.5) was associated with a higher risk of lung cancer (HR 1.35; 95% CI, 1.16-1.57), overweight and obesity were associated with a lower risk, with HRs of 0.77 (95% CI, 0.71-0.84) and 0.69 (95% CI, 0.45-1.07), respectively. Every 5 kg/m2 increase in BMI was associated with a 21% lower risk of lung cancer (HR 0.79; 95% CI, 0.75-0.83; p < 0.0001). Our pooled analysis indicated that BMI is inversely associated with the risk of lung cancer in the Japanese population. This inverse association could be partly attributed to residual confounding by smoking, as it was more pronounced among male smokers.

A cross-sectional study of the association between periodontitis and physical activity in the Japanese population.

OBJECTIVE: The aim of this study was to determine whether physical activity (PA) is associated with periodontitis in the Japanese population. BACKGROUND: The potential association between PA and periodontitis has not been thoroughly investigated in the Japanese population. METHODS: We used cross-sectional data from the Japan Public Health Center-based Prospective Study for the Next-Generation Oral Health Study. Periodontitis was determined by a full-mouth periodontal examination. PA was assessed using a validated questionnaire. We performed multivariable ordinal logistic regression analyses to assess the association of total PA (the first quintile was set as the reference category) with periodontitis (three categories: no/mild, moderate, and severe), stratified by sex. The associations of periodontitis with domain- and intensity-specific PA were also studied in separate logistic regression models. RESULTS: This study included 2160 Japanese adults [1414 women and 746 men; mean (standard deviation) age 58.1 (9.6) years]. After adjusting for potential confounders, total PA was inversely associated with the presence and severity of periodontitis in women. The multivariable-adjusted odds ratios (95% confidence intervals) for periodontitis in the second to fifth quintiles (compared with the first quintile) of total PA were 0.81 (0.59-1.12), 0.74 (0.53-1.02), 0.77 (0.55-1.06), and 0.64 (0.46-0.89), respectively (p for trend = .01). We did not find different results when we further investigated the associations of periodontitis with domain- and intensity-specific PA. By contrast, PA was not associated with periodontitis in men. CONCLUSION: Total PA had an inverse, linear association with the presence and severity of periodontitis in Japanese women but not in Japanese men. Further prospective studies are required to determine the association between PA and periodontitis.

Comparison of interproximal delivery and flow characteristics by dentifrice dilution and application of prepared toothpaste delivery technique.

In home care, the toothpaste technique, which can enhance the caries-preventive effect without changing the amount of dentifrice and fluoride ion concentration, is of great significance. This study aimed to construct a model and experimental system that reproduces the interdental part and to clarify the relationship between the change in dentifrice viscosity due to dilution and washout in the high-risk approximal area of caries. Additionally, the effectiveness of the toothpaste technique and appropriate devices for delivering dentifrice to the interdental area at a low dilution were investigated. Diluted toothpaste samples were prepared (: ×1.00, ×1.25, ×1.50, ×1.75, ×2.00, ×3.00, and ×4.00). An acrylic interproximal model was created for this experiment. The flow characteristics and viscosity by dentifrice dilution were measured. In the case of low dilution of 57% (1.75×) or more, it was shown that the dentifrice in the high-risk area may be washed out early because of the decrease in viscosity, and the caries-preventive effect may be reduced. It was also suggested that to keep the dentifrice in the interdental area for 120 s at the end of brushing, a dilution must be devised to a concentration of at least 50% (2.00×). The prepared toothpaste delivery (PTD) method of delivering dentifrice to the interdental area while maintaining it at a low dilution is an effective toothpaste technique in terms of dentifrice dilution and viscosity. The use of finger brushes in the PTD method could increase the efficiency of dentifrice delivery.

COVID-19-Related Factors Delaying Dental Visits of Workers in Japan.

BACKGROUND: The aim of this research was to investigate the factors associated with postponing dental attendance amongst Japanese workers during the coronavirus disease 2019 (COVID-19) pandemic. METHODS: We conducted an internet-based survey in Japan from November 24 to 29, 2021. The participants were selected from people registered with an online research company. The inclusion criteria for this study were full-time or part-time workers aged 20 to 69 years. Participants filled out a questionnaire about their oral health, behaviour, and working conditions. RESULTS: A total of 1840 participants were included in the analysis. Three hundred ninety-eight participants (21.5%) answered that they postponed dental attendance due to COVID-19. Multiple logistic regression showed that women were more likely to postpone dental attendance (odds ratio [OR], 1.74; 95% confidence interval, 1.33-2.26). Moreover, employment status, household income, changes in income, working at home, interdental cleaning device use, regular dental attendance, awareness of untreated teeth, and dental pain were also associated with postponing dental attendance. The results of decision tree analysis showed that regular dental attenders with dental pain were the most likely to postpone dental attendance. CONCLUSIONS: The characteristics of postponed dental visits for Japanese workers differ depending on whether one is a regular dental attender or not. Amongst regular dental attenders, worsening oral health due to interruptions in dental attendance is concerning. Meanwhile, untreated teeth might be neglected amongst nonregular dental attenders. Preventing patients from refraining from dental attendance, regardless of whether or not they are regular dental attenders, is important during the COVID-19 pandemic.

Relationship between Toothpaste Dilution Ratio and Droplets Generated during Tooth-Brushing.

Guidelines for using toothpaste during tooth-brushing in public places during the coronavirus epidemic are lacking. In addition, the advantages and disadvantages of using toothpaste in terms of droplet generation during brushing, the number of droplets generated, and their scatter range are unknown; therefore, we investigated the relationships between diluted toothpaste viscosity, the number of droplets generated, and the droplets' flight distance. We developed a system to quantitate droplet generation during tooth-brushing. Brushing with water generated 5965 ± 266 droplets; 10.0× diluted toothpaste generated 538 ± 56, 4.00× diluted toothpaste generated 349 ± 15, and 2.00× diluted toothpaste generated 69 ± 27 droplets. Undiluted toothpaste generated no droplets. Droplet number tended to increase with increased toothpaste dilution ratio and decreased viscosity (r = -0.993). The maximum flight distances were 429 ± 11, 445 ± 65, 316 ± 38, and 231 ± 21 mm for water, 10.0×, 4.00×, and 2.00× diluted toothpaste, respectively. The maximum flight distance and toothpaste viscosity correlated negatively (r = -0.999). Thus, the less diluted the toothpaste, the fewer the droplets generated during brushing, and the shorter their flight distance. The use of an appropriate amount of toothpaste is recommended to prevent droplet infection during tooth-brushing.

Reasons for Tooth Extractions in Japan: The Second Nationwide Survey.

BACKGROUND: More than 10 years have passed since the first nationwide study on the reasons for tooth extraction in Japan. In the present study, we conducted the second nationwide survey to update the previous data. METHODS: This was a descriptive study. A sample population consisting of 5,250 dentists was selected by systematic random sampling using the 2018 membership directory of the Japan Dental Association. The reason for each permanent tooth extraction was documented by each dentist during a period of 1 week from June 4 to June 10, 2018. A questionnaire was provided for documentation. Reasons for tooth extraction were categorised into 6 groups as follows: caries, periodontal disease, fracture, orthodontics, impacted teeth, and others. RESULTS: A total of 2345 identified dentists responded to the questionnaire (recovery rate: 44.8%). Information on 7809 extracted teeth from 6398 patients was obtained. Periodontal disease was the main reason for tooth extraction for both sexes (men: 40.4%, women: 34.9%). Caries accounted for 30.2% of tooth extractions among men and 29.0% among women. Periodontal disease was predominant in the groups older than 55 years of age. Dental fracture accounted for 16.8% of tooth extractions among men and 19.2% among women. CONCLUSIONS: Caries and periodontal disease are still the main reasons for tooth extraction in Japan. Moreover, dentists should note that fractures accounted for approximately one-fifth of permanent tooth extractions after the age of 45 years.

A Validation Study of the National Database of Health Insurance Claims and Specific Health Checkups of Japan Regarding the Annual Number of Tooth Extractions Performed Across the Entire Japanese Population.

This report describes a validation study of data in the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) obtained by nationwide surveys on tooth extractions. The following 3 data sources on tooth extractions in Japan were compared: (1) the Nationwide Survey of the Reasons for Permanent Tooth Extractions in Japan (a previous survey conducted by the present authors); (2) the Statistics on Medical Care Activities in Public Health Insurance; and (3) the 4th NDB Open Data Japan. Source 1 was a nationwide survey conducted in 2018; sources 2 and 3 comprised data that are freely available for use by the public. In Source 1, 2,345 of 5,250 dentists approached responded to the questionnaire (recovery rate: 44.8%). The number of extracted teeth among younger age groups (aged 25-50 years) reported in Source 1 was lower than that in the other two sources. In contrast, the number of extracted teeth among older age groups reported in Source 1 was higher than that reported in the other two sources. However, when stratified by age group, all differences across the 3 sources regarding the mean annual number of tooth extractions were <0.05 teeth/year. The present results suggest that the NDB is a reliable resource for data on tooth extractions performed across the entire Japanese population.

Self-Reported Diabetes Mellitus and Tooth Extraction Due to Periodontal Disease and Dental Caries in the Japanese Population.

Diabetes mellitus is closely related to oral health. We aimed to determine the relationship between diabetes mellitus and tooth extraction due to periodontal disease and dental caries. Japan's second nationwide survey data collected from 4 June to 10 June 2018 was used to identify reasons for tooth extraction among patients aged > 40 years. General dentists collected information on patients who underwent tooth extraction procedures, and the presence of diabetes mellitus was determined through interviews. Multivariable logistic regression was performed to investigate the relationship between diabetes mellitus and the reasons for tooth extraction, including periodontal disease and dental caries. In total, 2345 dentists responded to the survey (response rate 44.8%). We analyzed data on 4625 extracted teeth from 3750 patients (1815 males and 1935 females). Among patients with self-reported diabetes mellitus, 55.4% had extractions due to periodontal disease compared to 46.7% of such extractions among those without self-reported diabetes mellitus. Self-reported diabetes mellitus was significantly associated with tooth extraction due to periodontal disease. No significant differences were observed in dental caries according to self-reported diabetes mellitus status. This study provides further evidence of a significant association between diabetes mellitus and tooth extraction due to periodontal disease.

Evaluation of Public Health Expenditure by Number of Teeth among Outpatients with Diabetes Mellitus.

The relationship between public health expenditure and number of teeth was investigated in patients with diabetes mellitus using data obtained from the Japanese National Database of Health Insurance Claims and Specific Health Checkups. Data on medical, dental, and pharmacy claims generated between April 2015 and March 2016 were analyzed in patients with diabetes mellitus aged 50-74 years who used outpatient services during this period. Patients initiating medical and pharmacy claims related to diabetes mellitus were defined as having diabetes mellitus. Number of teeth was defined as number of teeth in conjunction with periodontitis due to the nature of the data source. Descriptive statistics were used to investigate the association between number of teeth and public health expenditure. Data on a total of 1,017,758 patients with diabetes mellitus were analyzed. Patients with the fewest teeth incurred higher medical expenses. The largest mean difference in medical expenditure was observed between patients with 5-9 teeth and those with over 28 teeth. The results of this study suggest that public health expenditure on patients with diabetes mellitus differs based on number of teeth.

Relationship between Obesity and Oral Health Behavior in Primary and Junior High School Students: A Cross-sectional Study.

It has been reported that people who brush their teeth frequently might be more health-conscious and maintain healthier lifestyle habits. The relationship between obesity and oral health behavior in childhood is unknown, however. The aim of the present study was to fill this gap by investigating obesity and factors associated with oral health behavior in Japanese primary and junior high school students. A total of 475 primary school students (fifth-grade, age 10-11 years) and 408 junior high school students (first-grade, age 12-13 years) were included. All the participants underwent a regular health check-up and completed a self-reported questionnaire. The data thus obtained were subjected to multiple logistic regression analyses to identify the relationship between obesity and factors associated with oral health behavior. In primary school students, a dislike of physical activity was the only factor showing a significant association with obesity (p<0.05). In addition, however, tooth brushing <2 times per day and a lack of regular clinical dental care showed a significant association with obesity in junior high school students (p<0.05). The present results suggest a significant association between regular clinical dental care and tooth brushing and obesity in junior school students.

Relationship between Obesity Indicators and Gingival Inflammation in Middle-aged Japanese Men.

The purpose of this study was to investigate the relationship among the waist-to-height ratio (WHtR) and the body mass index (BMI) as obesity indicators and gingival inflammation as determined by bleeding on probing (BOP). The participants comprised employees of a milk products company based in Tokyo, Japan. A total of 159 non-diabetic men aged 40 to 59 yr and with a minimum of 28 teeth were included. Multiple logistic regression analysis controlling for age, smoking status, pocket depth, frequency of daily brushing, frequency of weekly interdental brushing, and regular dental attendance was performed to compare the relationships among the obesity indicators and BOP. Participants with good oral hygiene had significantly less BOP than those with poor oral hygiene (p<0.001). No significant differences were observed among the other items investigated. A significant association was observed between WHtR and BOP (odds ratio: 2.40, 95% confidence interval: 1.11-5.22); no such association was observed with the BMI, however. The present results showed that obesity, as determined according to a visceral fat index, was associated with BOP, but not with BMI. This suggests that the WHtR is a more accurate index of obesity than the BMI in studies on BOP.

Modified toothpaste application using prepared toothpaste delivering technique increases interproximal fluoride toothpaste delivery.

OBJECTIVES: We devised a "prepared toothpaste delivering technique" (PTD technique), a modified the application of toothpaste method for using fluoride toothpaste more effectively. This study aimed to investigate the change in viscosity and fluoride intake into hydroxyapatite of a toothpaste, and deliverability of fluoride toothpaste to the interproximal site with the PTD technique using an interproximal model. METHODS: Eight toothpaste samples were prepared at the following concentrations: ×1.00, ×1.25, ×1.50, ×1.75, ×2.00, ×3.00, ×4.00, and ×5.00. Viscosity of the toothpaste was measured by a Type-B viscometer. Dissolution rate of toothpaste and fluoride uptake into the hydroxy apatite pellet were analyzed by a fluoride selective electrode. Application paste volume and delivery rate was measured using interproximal model and image analysis software during using a finger brush front (FBF), finger brush back (FBB), and toothbrush. RESULTS: As the dilution ratio increased, the viscosity of the toothpaste decreased sharply, F uptake decreased, and dissolution rate increased. F uptake was significantly reduced when the toothpaste was diluted more than 1.75 times. Therefore, in order to improve the effectiveness of the fluoride toothpaste, it is important to deliver the toothpaste to interproximal areas and pit clefts at low dilution. It was observed that PTD technique can be effectively implemented by the finger brush. CONCLUSIONS: The use of a FBF surface in the analysis of an acrylic interproximal model could aid in applying pressure while blocking the space of the groove and preventing outflow of the toothpaste. It was considered that the PTD technique would improve the effects of the fluoride toothpaste, especially in the interproximal site.

Evaluation of tooth loss among patients with diabetes mellitus using the National Database of Health Insurance Claims and Specific Health Checkups of Japan.

BACKGROUND: Although diabetes mellitus is reported to be related to tooth loss, there is limited population-based evidence for this relationship. We investigated the actual situation of tooth loss by performing a population-based survey using information obtained from the National Database of Health Insurance Claims and Specific Health Checkups (NDB) in Japan. METHODS: Medical, dental and pharmacy claims data generated between 1 April 2015 and 31 March 2016 were obtained and analysed. Patients with medical and pharmacy claims of diabetes mellitus were allocated to the diabetes mellitus group. Patients with medical claims of acute upper respiratory inflammation, but without claims of diabetes mellitus, were allocated to the control group. The number of claims involving tooth loss, treatment of periodontal disease and visits to medical and dental institutions were obtained from the NDB. Descriptive statistics were used to compare the nature of tooth loss between patients with diabetes mellitus and the control groups. RESULTS: There were 5,248,405 patients in the control group and 1,570,082 patients in the diabetes mellitus group. Patients in the diabetes mellitus group showed a higher level of tooth loss than patients in the control group, among both sexes. Patients with diabetes mellitus tended to lose their posterior teeth at an earlier age than patients in the control group. Moreover, patients in the diabetes mellitus group showed greater tooth loss, regardless of whether or not periodontal disease was treated. CONCLUSION: Patients with diabetes mellitus show a higher level of tooth loss than those without diabetes mellitus, based on the results of a population-based survey.

Factors associated with development of root caries in dentition without root caries experience in a 2-year cohort study in Japan.

OBJECTIVES: To investigate factors associated with the development of root caries in dentition without root caries experience and interactive relationships between risk factors. METHODS: We conducted surveys, consisting of an oral examination (oral hygiene, assessment of the number of teeth, coronal and root caries) and a self-reported questionnaire, among employees of a company in Tokyo, Japan in 2016 and 2018. Questionnaires collected data on smoking status, oral hygiene habits, sugar intake, and frequency of dental visits. Multiple logistic regression and decision tree analyses were used to determine factors associated with the development of root caries. RESULTS: A total of 299 participants aged 25-63 years were included in the analysis. Males, older adults, smokers/past smokers had a significantly greater risk of developing root caries. The risk of developing root caries was significantly associated with the number of teeth with gingival recession at baseline (6-9 teeth, odds ratio [OR]: 7.69, 95 % confidence interval [CI]: 2.31-25.56; 10+ teeth, OR: 9.19, 95 % CI: 2.73-30.95, relative to ≤5 teeth); and with the number of coronal decayed and filled (DF) teeth (11-13 teeth, OR: 3.21, 95 % CI: 1.12-9.24; and ≥14 teeth, OR: 3.60, 95 % CI: 1.27-10.20, relative to ≤10 teeth). Other factors associated with root caries development differed according to the number of teeth with gingival recession and included drinking sugar-sweetened beverages, and the amount of toothpaste used. CONCLUSIONS: Gingival recession and number of coronal DF teeth were associated with the development of root caries. CLINICAL SIGNIFICANCE: Multiple factors are associated with root caries development. The effect of risk factors such as drinking sweetened beverages and less toothpaste use is greater in individuals with greater gingival recession and more coronal decayed and filled teeth. Dental practitioners should focus on modifiable risk factors to prevent root caries.

Relationship between oral symptoms during diving work and preventative dental visits in Japanese male occupational divers.

This cross-sectional study examined the relationship between dental symptoms experienced by occupational divers during diving and their participation in preventative dental visits. The questionnaire for this study was sent by post to 160 establishments and 215 members of the Japan Diving Association and participants were asked to complete a self-reported questionnaire. Data from 242 occupational divers (male, aged 20-79 yr) were analyzed. Multiple logistic regression analysis and correspondence analysis were performed to determine the relationship between dental symptoms experienced during diving and participation in preventative dental visits. We found that divers who experienced tooth pain while diving had not undergone preventative dental visits within the previous year (odds ratio: 2.76, 95% confidence interval: 1.12-6.80). This was also confirmed by correspondence analysis These findings suggested that not undergoing preventative dental visits was related to tooth pain during diving.

Factors Associated with Untreated Decayed Teeth in Male Sales Workers: An Internet Survey.

The purpose of this study was to identify factors associated with untreated decayed teeth (DT) in male sales workers. The participants were recruited by screening a pool of Japanese registrants in an online database for eligibility for inclusion in the study. Between 20 February 2015 and 11 March 2015, those deemed eligible were asked to complete a questionnaire on the status of their oral health. Responses from a total of 142 male sales workers aged between 30 and 49 years were analyzed. Of these, 40 reported DT and 102 no untreated decayed teeth (NDT). The percentage of participants with DT was higher than that with NDT among night shift workers (p<0.001). A higher percentage of participants with DT reported pain when eating or drinking something cold (p=0.041), pain in the teeth or gingiva (p<0.001), or frequent stomatitis (p=0.030). A higher percentage of participants with DT reported eating between meals (p=0.027) and a lower percentage visiting a dental clinic in the past 6 months (p=0.017) compared with among participants with NDT. Those with NDT were more likely to report an inability to visit a dental clinic when they wanted to (p=0.033), but those with DT were more likely to report that their reasons for not visiting a dental clinic were that multiple visits were required for treatment (p=0.012) or that they did not like the treatment (p=0.005). Working the night shift (Odds Ratio [OR], 3.492; 95% Confidence Interval [CI], 1.347-8.725) and visiting a dental clinic in the past 6 months (OR, 0.084; 95%CI, 0.010-0.733) were identified as independent variables correlated with leaving DT untreated. Requiring oral health education and dental checkups at least once every 6 months may have a positive effect on oral health among male sales workers, especially those doing night shifts.

Relationship between Blood HbA1c Level and Decayed Teeth in Patients with Type 2 Diabetes: A Cross-sectional Study.

The purpose of this cross-sectional study was to determine whether there is an association between hemoglobin A1c (HbA1c) level and the presence or absence of decayed teeth in patients with type 2 diabetes mellitus. The patients and data on their age and sex, the presence or absence of dental claims, medical history of diabetes mellitus, and workplace dental examinations were obtained from a Japanese healthcare database available for epidemiological studies. The HbA1c levels were obtained from results of the Specific Health Checkups and Specific Health Guidance tests conducted by the Japanese Ministry of Health, Labour and Welfare. Data on a total of 1,897 patients were analyzed. Patients with poorly controlled diabetes (HbA1c≥6.5, n=779) had more decayed teeth than those in whom it was well controlled (HbA1c<6.5, n=1,118). Multiple logistic regression analysis with the presence or absence of decayed teeth as a dependent variable revealed a significant association between an HbA1c level of ≥8.0 and decayed teeth (odds ratio: 1.69; 95% confidence interval, 1.24-2.29), even after adjusting for dental attendance. This suggests that a poorly controlled blood HbA1c level is a risk factor for dental caries. More thorough oral hygiene instruction and education on preventive treatment for dental caries in patients with poorly controlled diabetes are needed.

Factors Associated with Undergoing Regular Dental Check-ups in Healthy Elderly Individuals.

The purpose of this study was to determine the distribution of healthy elderly individuals undergoing regular dental check-ups and identify any environmental or associated oral factors. A cross-sectional questionnaire survey was used to interview 216 individuals attending 2 welfare facilities for the elderly, of whom 160 were included in the final analysis. Items comprised age, sex, number of residual teeth, frequency of teeth/denture cleaning, subjective chewing ability, denture use, oral status, regular dental check-ups, visitation of the same dentist, number of dental visits in the past year, General Oral Health Assessment Index (GOHAI) (Japanese version) score, living situation, and use of routine medication. Individuals undergoing regular dental check-ups were defined as those with a primary dentist whom they saw for dental check-ups at least once a year. The rate of individuals undergoing regular dental check-ups was 75.0% in men aged 60-74 years, 58.8% in women aged 60-74 years, 70.0% in men aged 75 years or over, and 45.3% in women aged 75 years or over. Logistic regression analysis revealed a higher number of residual teeth (odds ratio [OR]=2.664 in comparison with those with fewer than 20 teeth, p=0.0427); cleaning teeth/dentures 3 or more times per day (OR=2.546 in comparison with cleaning them twice per day or less, p=0.0157); and a higher GOHAI score (OR=2.742 in comparison with those with a GOHAI score of less than 58, p=0.0263) as factors significantly correlated with undergoing regular dental check-ups. In conclusion, the results revealed that individuals undergoing regular dental check-ups had 20 or more residual teeth, cleaned their teeth/denture 3 or more times per day, and had a higher GOHAI score. This indicates that the best predictive factor for undergoing regular dental check-ups in healthy elderly individuals is their GOHAI score.

Number of Non-vital Teeth as Indicator of Tooth Loss during 10-year Maintenance: A Retrospective Study.

The purpose of this study was to investigate whether number of non-vital teeth was an indicator of tooth loss during maintenance. Thirty-three general practitioners provided data on 321 patients undergoing maintenance over 10 years. The number of present teeth (PT), smoking status, level of bone loss, number of non-vital teeth, and reason for tooth loss during that period were investigated. Multiple logistic regression was performed to identify whether the number of non-vital teeth was associated with tooth loss. The average number of lost teeth was 1.07±1.82; that of PT at baseline was 24.4±3.9; and that of non-vital teeth at baseline was 5.4±4.5. Multiple logistic regression revealed a significant association between >8 non-vital teeth and tooth loss during maintenance (odds ratio [OR]: 2.40; 95% confidence interval [CI]: 1.18-4.87). It also demonstrated relationships between >8 non-vital teeth and root fracture or caries (OR: 3.90; 95%CI: 1.68-9.03 or OR: 2.85, 95%CI: 1.14-7.10, respectively). The number of non-vital teeth was associated with tooth loss during maintenance. The results suggest that patients with many non-vital teeth before commencement of maintenance are particularly at risk of tooth loss due to root fracture or caries. Therefore, the number of non-vital teeth offers a useful indicator of potential tooth loss.