Prosthodontic treatment can improve the ingestible food profile in Japanese adult outpatients.

PURPOSE: To investigate the effect of prosthodontic treatment on the ingestible food profile in adult Japanese outpatients, and to identify the related risk factors that can deteriorate the profile. METHODS: The participants were 277 outpatients who visited university-based specialty clinics in Japan for prosthodontic treatment. The demographic data, number of present teeth assessed via intraoral examination, and oral health-related quality of life assessed by the total Oral Health Impact Profile (OHIP-J54) scores of all participants were recorded before treatment. Ingestible food profile score (IFS) was recorded using a validated food intake questionnaire. Eligible participants who answered the questionnaire before and after treatment were categorized into five groups based on the prosthodontic treatments they received (i.e., crowns, bridges, removable partial dentures, removable complete dentures, and removable complete and partial dentures). RESULTS: Multivariate analysis of covariance revealed a statistically significant main effect of prosthodontic intervention (time course: before and after treatment) on mean IFS (P=0.035, F=4.526), even after adjusting for covariates (age, number of present teeth, and treatment modality). Multiple linear regression analysis revealed that the low number of present teeth (r=0.427, P<0.001) and a high OHIP-J54 total score (r=-0.519, P<0.001) of the patients at the baseline were significantly associated with their baseline IFSs, even after adjusting for confounding variables. CONCLUSIONS: The findings of this multicenter follow-up study indicate the importance of prosthodontic rehabilitation in improving patients' ingestible food profiles.

A multi-centered epidemiological study evaluating the validity of the treatment difficulty indices developed by the Japan Prosthodontic Society.

PURPOSE: The Japan Prosthodontic Society developed a multi-axis assessment protocol to evaluate the complex variations in patients who need prosthodontic care, and to classify the level of treatment difficulty. A previous report found the protocol to be sufficiently reliable. The purpose of this multi-center cohort study was to evaluate the validity of this multi-axis assessment protocol. METHODS: The treatment difficulty was evaluated using the multi-axis assessment protocol before starting prosthodontic treatment. The time required for active prosthodontic treatment, medical resources such as treatment cost, and changes in the oral health-related QOL before and after treatment, were evaluated after treatment completion. The construct validity of this protocol was assessed by the correlation between the dentist's pre-operative subjective assessment of the treatment difficulty, and the level of difficulty determined by this protocol. The predictive validity was assessed estimating the correlations between a "comprehensive level of treatment difficulty" based on the four axes of this protocol and total treatment cost, total treatment time, and changes in the oral health-related QOL before and after treatment. RESULTS: The construct validity of this protocol was well documented except for psychological assessment. Regarding the predictive validity, the comprehensive level of treatment difficulty assessed before treatment was significantly correlated with the three surrogate endpoints known to be related to the treatment difficulty (total treatment cost, treatment time, and improvement in the oral health-related QOL). To further clarify the validity of the protocol according to patients' oral condition, a subgroup analysis by defects was performed. Analyses revealed that treatment difficulty assessment before treatment was significantly related to one or two surrogate endpoints in the fully edentulous patients and the partially edentulous patients. No significant relationship was observed in the patients with mixture of full/partial edentulism and the patients with teeth problems, possibly due to the small sample size in these groups. CONCLUSION: This study revealed that the multi-axis assessment protocol was sufficiently valid to predict the level of treatment difficulty in prosthodontic care in patients with fully edentulous defects and with partially edentulous defects.

Japan Prosthodontic Society position paper on "occlusal discomfort syndrome".

PURPOSE: Dentists may encounter patients who present with a sense of a malocclusion but in whom no objective findings can be detected. For the patient who insists that there is occlusal discomfort, in the absence of evidence some dentists elect to perform an occlusal adjustment that not only fails to alleviate symptoms, and may, in fact, exacerbate the discomfort. The patient-dentist relationship is then likely compromised because of a lack of trust. STUDY SELECTION: In 2011, the Clinical Practice Guidelines Committee of the Japan Prosthodontic Society formulated guidelines for the management of occlusal discomfort. When formulating clinical practice guidelines, the committee bases their recommendations on information derived from scientific evidence. For "occlusal dysesthesia," however, there are an insufficient number of high-quality papers related to the subject. Therefore, a consensus meeting was convened by the Japan Prosthodontic Society to examine evidence in the Japanese- and English-language literature and generate a multi-center survey to create an appropriate appellation for this condition. RESULTS: As a result of the consensus meeting and survey findings, this condition may be justifiably termed "occlusal discomfort syndrome." CONCLUSIONS: The Japan Prosthodontics Society believes that identification of an umbrella term for occlusal discomfort might serve as a useful guide to formulating clinical practice guidelines in the future. This position paper represents summary findings in the literature combined with the results of a multicenter survey focused on dental occlusal treatment and the condition of patients who present with occlusal discomfort syndrome.

Relationship between behavioral and psychological symptoms of dementia and oral health status in the elderly with vascular dementia.

OBJECTIVES: The aim of this study was to clarify the relationship between behavioral and psychological symptoms of dementia (BPSD) and oral status in the elderly with vascular dementia. BACKGROUND: There have been some reports of a relationship between disease symptoms and oral status in the elderly with Alzheimer's disease, but few reports have been conducted in the elderly with vascular dementia. Until now, the relationship between BPSD and oral status has been unknown. MATERIALS AND METHODS: An investigation was conducted concerning BPSD and oral status among 57 subjects with vascular dementia (mean age, 85.7 ± 5.5 years). The wearing of dentures and oral activities of daily living (oral ADL) were examined. RESULTS: Subjects with activity disturbances and those with aggressiveness had significantly lower rates of denture wearing than those without these two symptoms (p < 0.05). Significantly lower oral ADL scores were obtained from subjects with delusional ideas, hallucinations, activity disturbances and diurnal rhythm disturbances (p < 0.05), as well as those with affective disturbances (p< 0.01). CONCLUSION: This study indicated a relationship between BPSD and the wearing of dentures in the elderly with vascular dementia. The study also demonstrated relationships between BPSD and oral ADL.

Nutritional status and oral status of the elderly with dementia: a 2-year study.

OBJECTIVES: To determine the relationship between denture wearing and nutritional status in the elderly with dementia. BACKGROUND: There could be a correlation between nutrition, oral health, dietary habits, patients' satisfaction, and their socio-economic status in the elderly, and the relationship between compromised oral status and nutritional status in the elderly with dementia. SUBJECTS AND METHODS: A 2-year follow-up study of 63 elderly Japanese women with and without dentures from a nursing home was undertaken to investigate their oral, physical and mental, and nutritional status. RESULTS: Each item for 2006 and 2008 in this study showed no significant difference between 2006 and 2008, except the calories/day. The elderly with dementia without complete dentures during the 2 years of the study only significantly decreased the mean of the calories/day. CONCLUSION: The calories/day of the elderly with dementia without dentures decreased after 2 years. Denture wearing for the elderly with dementia could be necessary to maintain a satisfactory intake of calories.

Durability of peel bond of resilient denture liners to acrylic denture base resin.

PURPOSE: The purpose of this study was to determine the durability of the peel bond of commercial resilient denture liners to a denture base resin using a thermal cycling test. METHODS: Eight commercial resilient denture liners (five silicone and three acrylic) were used in the study. The samples were exposed to thermal cycles between 5°C and 55°C for 1 min for 0, 1,250, 2,500, 5,000 and 10,000 cycles. The test samples were placed under tension until failure in a materials testing machine using a crosshead speed of 20 mm/min. The modes of debonding were characterized as tear, peel or snap. Statistical analysis was performed using one-way and two-way analysis of variance and Student-Newman-Keuls multiple comparison tests (α=.05). RESULTS: A significant difference was found between different resilient denture liners for peel bond strength at 0 cycles. No extreme influence on the peel bond strength was observed under any of the thermal cycles. The snap mode of debonding was observed in most samples of all materials for all cycles. CONCLUSION: All resilient denture liners tested had a sufficiently strong bond to the denture base resin. Within the limitations of this study, the results show that all of the materials were acceptable for clinical use, having met the accepted adequate bond strength for resilient denture liners of 0.45 MPa.

Association between sleep bruxism and stress sensitivity in an experimental psychological stress task.

The objective of this study was to examine the association between sleep bruxism and psychological stress. The subjects consisted of 76 volunteers, who were divided into those with and without bruxism according to the diagnostic criteria for sleep bruxism outlined by the American Academy of Sleep Medicine (AASM). Stress sensitivity was evaluated before and after an experimental stress task, which involved simple mathematical calculations. It was assessed objectively by measuring the subjects' salivary chromogranin A (CgA) levels and subjectively using a ten-division visual analog scale (VAS). Compared with those observed before the stress task, the mean salivary CgA levels of the non-bruxism group (n = 54) were not significantly increased after the stress task. Conversely, the mean salivary CgA levels of the bruxism group (n = 22) were significantly increased after the stress task (P < 0.01). The mean VAS scores of the groups without (n = 54) and with (n = 22) bruxism were significantly (P < 0.01) increased after the stress task compared with those observed before the stress task, but no differences were detected between the two groups in the stress task. These findings suggest that there is an association between sleep bruxism and psychological stress sensitivity.

Effect of PMMA polymer on the dynamic viscoelasticity and plasticizer leachability of PEMA-based tissue conditioners.

The purpose of this study was to determine the effect of PMMA polymer on dynamic viscoelasticity and plasticizer leachability of PEMA-based tissue conditioners. One PEMA polymer and one PMMA polymer were used in powder form with four formulations. The combination of 80 wt% ATBC, 15 wt% BPBG and 5 wt% ethyl alcohol was used as the liquid phase. The dynamic viscoelasticity and plasticizer leaching of each specimen were measured after 0, 1, 3, 7, and 14 days of immersion (37 degrees C distilled water) using DMA and HPLC. A significant difference was found among the materials in the dynamic viscoelasticity and leaching of plasticizer. The materials containing 10 wt% PMMA showed the most stable dynamic viscoelasticity, and showed the lowest leaching of plasticizer. The results suggest that the addition of the PMMA polymer to the powder of a tissue conditioner can improve the durability of the PEMA-based tissue conditioner.

Influence of storage methods on the surface roughness of tissue conditioners.

The purpose of this study was to compare the influence of three kinds of storage methods on surface roughness of tissue conditioners. Four commercial tissue conditioners (GC Soft Liner, Softone, Fictioner, and Hydro-Cast) were used in this study. Five samples of each material were stored in distilled water, air, and a denture cleanser (Polident). Mean surface roughness (R(a)) values of dental stone casts made from the tissue conditioners were measured after 0, 1, 3, 7, and 14 days of immersion using a profilometer. Significant differences in the R(a) values of the specimens were found among the three storage methods. The values of R(a) significantly increased with increase in immersion time for each storage method, except for the materials stored in air. It was found that the materials stored in air showed the most stable and lowest values of R(a). Results obtained suggested that a tissue conditioner exhibited smooth and minimal change in surface roughness with time when stored in air than in distilled water and denture cleanser.

The initial effects of occlusal splint vertical thickness on the nocturnal EMG activities of masticatory muscles in subjects with a bruxism habit.

PURPOSE: The objective of this study was to investigate the initial effects of the vertical thickness of occlusal splints on the electromyographic (EMG) activities (integrated EMG values) of temporal and masseter muscles during sleep in subjects with a nocturnal bruxism habit using a portable EMG recorder. MATERIALS AND METHODS: The subjects consisted of 12 volunteers (4 men and 8 women, average age of 25.3 years). All subjects had never worn splints before and had a habit of nocturnal bruxism. Two types of splint were made for every subject: a splint with a 3-mm vertical thickness at the central incisors (S3) and a splint with a 6-mm vertical thickness (S6). The muscle activities of the left anterior temporal muscles and masseter muscles were recorded without occlusal splints (NS), with the S3 splint, and with the S6 splint by a portable EMG recorder. The integrated EMG values were calculated to examine muscle activities under the 3 different conditions. RESULTS: The integrated EMG values of masseter and temporal muscles decreased following insertion of the S3 splint but were not significantly affected by the S6 splint. Six subjects in masseter EMG and 7 subjects in temporal EMG got worse with the S6 splint compared to NS. CONCLUSIONS: When the occlusal splints were used as a bruxism countermeasure, it was suggested from the analysis of muscle activities during sleep at night that the S3 splint was superior to the S6 splint.

The relationships between oral status, physical and mental health, nutritional status and diet type in elderly Japanese women with dementia.

OBJECTIVES: To suggest methods for maintaining an adequate nutritional status for elderly patients with dementia by evaluating the relationships between oral status, physical and mental health, and feeding conditions. BACKGROUND: Feeding difficulties in dementia patients are related to food intake, and failure to eat may be associated with weight loss in long-term care facilities. The relationship between compromised oral function and diet is still unclear. MATERIALS AND METHODS: A cross-sectional study of 94 elderly women with dementia (mean age 89.6 +/- 5.6 years) from a nursing home was undertaken to investigate their oral, physical and mental and nutritional status. RESULTS: There were significant differences in serum albumin (p = 0.0284), N-ADL (p = 0.0005), NM scale (p = 0.0004) and HDS-R (p = 0.0004) between denture wearers and non-denture wearers. However, there were no significant differences in body mass index between denture wearers and non-denture wearers. CONCLUSION: A suitable type of diet and assistance with feeding could maintain the nutritional status of elderly patients with dementia if they are still feeding themselves. The nutritional support team will benefit from the participation of a dentist.