Sayaka Tada

Significance of occlusal force for dietary fibre and vitamin intakes in independently living 70-year-old Japanese: from SONIC Study

OBJECTIVES The number of teeth has frequently been used as an indicator of oral health in investigations of food intake; however, this measure does not represent the efficacy of the masticatory performance. Masticatory performance may be more important for food selection and avoidance than number of remaining teeth. The aim of this study was to investigate the association of occlusal force with habitual dietary intakes in independently living older Japanese. METHODS The study population was 757 community-dwelling people aged 69-71 years old. Bilateral maximal occlusal force in the intercuspal position was measured with pressure-sensitive sheets. Removable denture wearers kept their dentures in place during the measurements. Dietary habits during the preceding month were assessed using a brief-type self-administered diet history questionnaire that measures consumption frequencies of selected food commonly consumed and calculates energy-adjusted dietary intakes. Linear trends of food and nutrient intakes with decreasing occlusal force were tested after adjusting for gender and socioeconomic factors. RESULTS After adjusting for socioeconomic status and the number of remaining teeth, decline of occlusal force was significantly associated with lower intakes of vegetables, vitamins A, C, B6, folate, and dietary fibre (P for trend<0.05). In contrast, number of teeth was significantly associated only with calcium and zinc, controlling for occlusal force. CONCLUSIONS It is concluded that occlusal force was significantly associated with intakes of vitamins and dietary fibre rather than number of remaining teeth in independently living older Japanese.

Multifactorial risk assessment for survival of abutments of removable partial dentures based on practice-based longitudinal study

OBJECTIVES Predicting the tooth survival is such a great challenge for evidence-based dentistry. To prevent further tooth loss of partially edentulous patients, estimation of individualized risk and benefit for each residual tooth is important to the clinical decision-making. While there are several reports indicating a risk of losing the abutment teeth of RPDs, there are no existing reports exploring the cause of abutment loss by multifactorial analysis. The aim of this practice-based longitudinal study was to determine the prognostic factors affecting the survival period of RPD abutments using a multifactorial risk assessment. METHODS One hundred and forty-seven patients had been previously provided with a total of 236 new RPDs at the Osaka University Dental Hospital; the 856 abutments for these RPDs were analyzed. Survival of abutment teeth was estimated using the Kaplan-Meier method. Multivariate analysis was conducted by Coxs proportional hazard modelling. RESULTS The 5-year survival rates were 86.6% for direct abutments and 93.1% for indirect abutments, compared with 95.8% survival in non-abutment teeth. The multivariate analysis showed that abutment survival was significantly associated with crown-root ratio (hazard ratio (HR): 3.13), root canal treatment (HR: 2.93), pocket depth (HR: 2.51), type of abutments (HR: 2.19) and occlusal support (HR: 1.90). CONCLUSION From this practice-based longitudinal study, we concluded that RPD abutment teeth are more likely to be lost than other residual teeth. From the multifactorial risk factor assessment, several prognostic factors, such as occlusal support, crown-root ratio, root canal treatment, and pocket depth were suggested. CLINICAL SIGNIFICANCE These results could be used to estimate the individualized risk for the residual teeth, to predict the prognosis of RPD abutments and to facilitate an evidence-based clinical decision making.

Association of personality traits with oral health-related quality of life independently of objective oral health status: A study of community-dwelling elderly Japanese

OBJECTIVES Oral health-related quality of life (OHRQoL) is being increasingly used in epidemiologic studies of dentistry. However, patient-reported OHRQoL does not always coincide with clinical measures. Previous studies have shown a relationship between OHRQoL and personality, but did not concomitantly investigate oral function. We aimed to examine the association among personality traits, oral function, and OHRQoL using a large sample of community-dwelling Japanese elderly. METHODS The participants (n = 938; age, 69-71 years) were drawn from a complete enumeration of an urban area and a rural area of both the Tokyo metropolitan area and Hyogo Prefecture. The self-perceived impact of OHRQoL was measured using the Geriatric Oral Health Assessment Index (GOHAI). The oral status and socioeconomic characteristics were recorded in each participant, and personality traits (neuroticism, extraversion, openness to experience, agreeableness, and conscientiousness) were assessed with the NEO-five-factor inventory. Multiple linear regression analysis was performed to examine the relationships between OHRQoL and other factors, with p < 0.05 considered to be statistically significant. RESULTS Neuroticism was negatively associated with the GOHAI score in bivariate analyses (Spearman rank-order correlation coefficient (rs )= -0.20), whereas extraversion was positively associated (rs = 0.17). In the regression analyses, neuroticism (standardized partial regression coefficient (β) = -0.179) and extraversion (β=0.094) were significantly associated with the GOHAI scores independently of the number of teeth, maximal occlusal force, and financial status. CONCLUSIONS Personality traits are associated with OHRQoL independently of objective measures of oral health status in community-dwelling elderly Japanese. CLINICAL SIGNIFICANCE This study showed personality traits are associated with OHRQoL independently of dental status and oral function in old Japanese people. As elderly patients undergo increasingly complex dental treatments, there is a need to evaluate patient personality traits prior to dental treatment and predict patient expectations and responses to planned treatment. This is advantageous in determining the most appropriate therapy.

Incidence and association of root fractures after prosthetic treatment.

PURPOSE Common reasons for tooth extractions include periodontal disease, dental caries and root fracture. The purpose of this study was to investigate the association of tooth loss after prosthetic treatment, particularly incidences due to root fracture, which occur frequently and are difficult to prevent. METHODS Data were collected from consecutively selected medical records of patients taken over 3 years after their initial visit to Osaka University Dental Hospital. Collected data included (1) age and gender, (2) number of teeth at the initial visit and number of extracted teeth, (3) reasons for extraction, (4) restored with or without a post and (5) abutment of removable partial dentures (RPDs). A Chi-squared test was applied among the reasons for extraction, whether the tooth was restored with a post or not and clasped or not. A logistic regression analysis was used to determine the associations of root fracture with the patient data. RESULTS This study included 101 patients (296 extracted teeth). The reasons for extraction included periodontal disease (64.6%), caries (25.3%) and root fracture (10.1%). The percentage of root fracture was significantly higher for female than male, for restored teeth with posts than without posts and for abutment of RPDs than for non-abutment teeth. Logistic regressions showed that root fractures were significantly associated with gender and abutments. CONCLUSION The most frequently stated reasons for tooth extraction after prosthetic treatment were periodontal disease and dental caries, followed by root fracture. Root fractures were significantly associated with gender and abutment teeth of RPDs.

The Impact of the Crown-Root Ratio on Survival of Abutment Teeth for Dentures

Crown-root ratio (CRR) is commonly recorded when planning prosthodontic procedures. However, there is a lack of longitudinal clinical data evaluating the association between CRR and tooth survival. The aim of this longitudinal practice-based study was to assess the impact of CRR on the survival of abutment teeth for removable partial dentures (RPDs). Data were collected from 147 patients provided with RPDs at a dental hospital in Japan. In total, 236 clasp-retained RPDs and 856 abutment teeth were analyzed. Survival of abutment teeth was assessed using Kaplan-Meier methods and Cox’s proportional hazard (PH) regression. The Cox PH regression was used to assess the prognostic significance of initial CRR value with adjustments for clinically relevant factors, including age, sex, frequency of periodontal maintenance programs, occlusal support area, type of abutment tooth, status of endodontic treatment, and probing pocket depth. Abutment teeth were divided into 1 of 5 risk groups according to CRR: A (≤0.75), B (0.76–1.00), C (1.01–1.25), D (1.26–1.50) and E (≥1.51). The 7-year survival rate was 89.1% for group A, 85.9% for group B, 86.5% for group C, 76.9% for group D, and 46.7% for group E. The survival curves of groups A, B, and C were illustrated to be quite similar and favorable. The multivariable analysis treating CRR as a continuous variable allowed estimation of the hazard ratio at any specific CRR value. When CRR = 0.80 was set as a reference, the estimated hazard ratio was 0.58 for CRR = 0.50 (95% confidence interval [CI], 0.36–0.91), 1.13 for CRR = 1.00 (95% CI, 0.93–1.37), 1.35 for CRR = 1.25 (95% CI, 1.02–1.80), 1.53 for CRR = 1.50 (95% CI, 1.15–2.08), or 1.95 for CRR = 2.00 (95% CI, 1.44–2.65). These practice-based longitudinal data provide information to improve the evidence-based prognosis of teeth in providing prosthodontic procedures.

Dietary Intake Is Associated with Occlusal Force Rather Than Number of Teeth in 80-y-Old Japanese

There has been a growing interest in the association between the number of teeth and dietary intake in older populations. However, people around the age of 80 y have frequently lost most of their teeth, and dental prostheses replacing the missing teeth play an important role in masticatory function. Therefore, masticatory function cannot be evaluated by the number of teeth alone. The occlusal force of the complete dental arches is an index of masticatory function, reflecting not only the number of teeth, but the effect of removable dentures. The purpose of this cross-sectional study was to determine the relative importance of the number of teeth and occlusal force in association with dietary intake in 80-y-old Japanese people. This study included 760 community-dwelling Japanese people aged 79 y to 81 y. The authors measured bilateral maximal occlusal force in the intercuspal position using pressure-sensitive sheets. Removable denture wearers kept their dentures in place during the measurements. Energy-adjusted food groups and nutrient intake during the preceding month were assessed by a brief self-administered diet history questionnaire. The authors assessed linear trends in food and nutrient intake in relation to the number of teeth and occlusal force after adjusting for gender and socioeconomic status (education level, financial status, family structure, resident area and BMI). P values of < 0.05 were considered to be statistically significant. The authors found that the number of teeth was not associated with the energy-adjusted intake of any food group examined. In contrast, a decline in occlusal force was significantly associated with a lower intake of vegetables, fish and shellfish, protein, polyunsaturated fatty acids, dietary fiber and most vitamins and minerals ( P for trend < 0.05). We conclude that food and nutrient intake was more closely associated with occlusal force than the number of teeth in community-dwelling Japanese people aged 79 y to 81 y. Knowledge Transfer Statement: This cross-sectional study of older Japanese people showed that, after controlling for considerable covariates, occlusal force rather than the number of teeth is positively associated with energy-adjusted intake of vegetables, fish and shellfish, protein, polyunsaturated fatty acids, dietary fiber and most of vitamins and minerals. This means that reduced occlusal force may unconsciously lead older people toward a habitual unhealthy dietary intake. Older people have frequently lost most of their teeth and require prosthetics to restore masticatory function. Bilateral occlusal force is therefore a better measure of masticatory function than the number of remaining teeth. Our findings suggest that prosthetic rehabilitation is a significant factor in the prevention and management of chronic diseases and frailty through better dietary intake in older populations.

Evaluation of Biodentine in the Restoration of Root Caries A Randomized Controlled Trial

There is no “gold-standard” material for the operative management of root caries. The aim of this study was to determine if the clinical performance of Biodentine would be acceptable for the restoration of root caries in older adults. A randomized controlled clinical trial was conducted comparing a calcium silicate cement (Biodentine), a high-viscosity glass ionomer cement (Fuji IX GP Extra), and a resin-modified glass ionomer cement (Fuji II LC). Of the 334 volunteers assessed for eligibility, 249 were excluded. A total of 303 lesions in 85 participants were randomized, with 151 lesions allocated to receive Biodentine, 77 to Fuji IX GP Extra, and 77 to Fuji II LC. Patients were reviewed by a calibrated dentist who was not involved in restoration placement and who was blinded to material allocation. Restorations were assessed according to a modified US Public Health Service criteria. The cumulative survival percentages after 6 mo and 1 y were 58.6% and 47.2% in the Biodentine group, 89.6% and 83.8% in the Fuji IX GP Extra group, and 89.5% and 84.9% in the Fuji II LC group, respectively. There were statistically significant differences (χ2 test, P < 0.001) in restoration failure rates between restoration groups. There was no difference between Fuji IX GP Extra and Fuji II LC, but differences (P < 0.001) were shown between the Fuji II GP Extra group and the Biodentine group and also between the Fuji II LC group and the Biodentine group at both time points. Based on the results of this study, Biodentine cannot be recommended for the operative management of root caries. Fuji IX GP Extra and Fuji II LC displayed similar success rates, and high-viscosity glass ionomer cement and resin-modified glass ionomer cement continue to be the best available option for the restoration of root caries (ClinicalTrials.gov NCT01866059). Knowledge Transfer Statement: The results of this study can assist dental practitioners when selecting a restorative material for the operative management of root caries. This randomized controlled trial compared the 1-y clinical performance of a calcium silicate–based material to that of a high-viscosity glass ionomer cement and a resin-modified glass ionomer cement in the operative management of root caries. The study concluded that high-viscosity glass ionomer cement and resin-modified glass ionomer cement continue to be the best available option to dental practitioners when restoring the root surface.

Relationship between atherosclerosis and occlusal support of natural teeth with mediating effect of atheroprotective nutrients: From the SONIC study

Whereas most of studies investigating relationship between oral health and atherosclerosis have focused on periodontitis, very few of them were examined about occlusal status of natural teeth which possibly influence dietary habit. The primary aim of this cross-sectional study was to investigate the association between the occlusal support of posterior teeth and the prevalence of atherosclerosis in community-dwelling septuagenarians. Also, the second aim was to test the hypothesis that the intake of key nutrients for atherosclerosis prevention would have a mediating effect on the relationship between the occlusal status and atherosclerosis. The study population included 468 community-dwelling dentate persons aged 69–71 years recruited from the local residential registration in Japan. Participants were divided into three groups, according to the number of occlusal support zones (OSZ) in the posterior area: Complete (four OSZ), Moderate (three or two OSZ), and Collapsed (one or no OSZ). Dietary intakes were assessed using a brief-type self-administered diet history questionnaire. Atherosclerosis was defined as carotid intima-media thickness ≧1.10 mm by using carotid ultrasonography test. The logistic or linear regression model was used in multivariate analysis to assess relationship between occlusal status and atherosclerosis, and the mediating effect of key nutrients within the relationship. Multivariable analysis showed a significant association between occlusal status and atherosclerosis (odds ratio for Collapsed group to Complete group: 1.87; 95% CI: 1.45–2.41), independent of periodontal status (odds ratio: 2.01, 95%CI: 1.46–2.78). Fish and shellfish, vitamin B6 and n-3PUFAs were significantly related to both of occlusal status and atherosclerosis, and also was indicated a mediating effect on the association between occlusal status and atherosclerosis. This study implied that, within the limitation of the cross-sectional study design, the reduced posterior occlusion was related to the increased prevalence of atherosclerosis via the decline of key dietary intakes among Japanese community-dwelling dentate individuals.

Geriatric dentistry education and context in a selection of countries in 5 continents: GERIATRIC DENTISTRY EDUCATION IN SELECTED COUNTRIES

PURPOSE/AIM To summarize and discuss how geriatric dentistry has been addressed in dental schools of different countries regarding to (1) teaching students at the predoctoral level; (2) advanced training, and (3) research. METHOD AND MATERIALS A convenience sample of faculty members from a selection of high, upper-middle and lower-middle income countries were recruited to complete the survey. The survey had 5 open-ended main topics, and asked about (1) the size of their elderly population, (2) general information about dental education; (3) the number of dental schools teaching geriatric dentistry, and their teaching methods; (4) advanced training in geriatric dentistry; (5) scholarship/research in geriatric dentistry. RESULTS AND CONCLUSION (1) There is great variation in the size of elderly population; (2) duration of training and content of dental education curriculum varies; (3) geriatric dentistry has not been established as a standalone course in dental schools in the majority of the countries, (4) most countries, with the exception of Japan, lack adequate number of dentists trained in geriatric dentistry as well as training programs, and (5) geriatric dentistry-related research has increased in recent years in scope and content, although the majority of these papers are not in English.

Loss of natural abutment teeth with cast copings retaining overdentures: a systematic review and meta-analysis

PURPOSE To analyze the available evidence in the English, German and Japanese literature on the survival and complications of natural teeth with cast copings used to retain overdentures (ROD). STUDY SELECTION A systematic search strategy was conducted using MeSH terms and pre-defined criteria. Two groups of researchers searched Pubmed, CENTRAL, Embase (English, German), Ichushi-web (Japanese) as well as hand searching. Data were extracted independently by the two groups. The estimated frequency of abutment tooth loss was calculated from data on the number of lost teeth and exposure time. A meta-analysis was conducted to estimate the annual frequency of abutment tooth loss across all included studies. RESULTS A total of 4791 eligible studies from PubMed, Embase, and CENTRAL. An additional 316 articles were identified from the Ichushi-Web plus another 131 articles from additional sources. From those manuscripts, 19 reported relevant outcome data that was then extracted. The pooled data included a total of 1954 abutment teeth with a combined total exposure time of 9098 years. The estimated linear rate of loss was 1.76 %/year (95 %CI 1.13; 2.72). Caries and periodontal infections were identified as the most common reasons for abutment tooth loss. CONCLUSIONS Natural tooth retained overdentures often constitute the last resort before edentulism and might aid in this transition, especially in very old patients with reduced adaptive capacities. Given correct design, preparation and aftercare, RODs with cast copings, still are a valid treatment option in partially edentulous patients.