Kazuhiro Shimoyama

Long-term observation of the relation between pain intensity and serum carbamazepine concentration in elderly patients with trigeminal neuralgia

The relation between changes in pain intensity and serum carbamazepine (CBZ) concentration was studied in five elderly patients with trigeminal neuralgia. Measurement of pain intensity and serum CBZ concentration, and blood studies, were performed approximately every 2 or 3 months after initiation of CBZ therapy. Fluctuations in pain intensity were observed in four patients. In these patients, even when the serum CBZ concentration was maintained within a relatively high range, there were periods in which pain intensity increased. On the other hand, there were periods in which pain was relatively well controlled even though the CBZ concentration was relatively low. There were considerable interindividual differences in response to CBZ. The fluctuations in pain showed that the CBZ response curve varies from period to period even within an individual. It was concluded that it is essential to observe spontaneous variations in pain intensity and monitor serum CBZ during long-term administration.

Factors affecting the motivation for dental check-ups and anxiety in the elderly in Tokyo

OBJECTIVES The purpose of this study was to identify factors influencing the motivation for regular dental check-ups and anxiety about future dental problems in the elderly. BACKGROUND Regular dental check-ups are important to maintain oral health. Anxiety affects the quality of life of the elderly. However, few studies have investigated the factors influencing the motivation for regular dental check-ups and anxiety in the elderly. MATERIALS AND METHODS Among 452 elderly persons, 215 participants provided useful answers to our questionnaire. The questionnaire consisted of items concerning oral and living conditions of the subjects. Logistic regression analysis was conducted. RESULTS The mean age of the study sample was 75.7 +/- 5.8 years. The percentage of edentulous subjects was 12.1%. The motivation for regular dental check-ups was significantly positively correlated with the number of teeth present (p < 0.01), using inter-dental brushes (p < 0.01), being on regular prescribed medication (p < 0.05), and having experience of providing oral care for the bedridden (p < 0.05). Anxiety about future oral problems was significantly associated with self-rated health status (p < 0.01) and the presence of dentists who could be counted on to provide domiciliary visits (p < 0.05). CONCLUSION The participants of this study had a high motivation for regular dental check-ups, but were concerned about the future, particularly if they became bedridden.

Mechanical properties of artificial teeth

In selecting the teeth for fabrication of complete or partial dentures, each patients anatomic and physiologic requirements and the properties of the artificial teeth themselves should be taken into consideration. The purpose of this study was to evaluate the mechanical properties of the artificial teeth by the static compression test and the impact test. Specimens were the lower first molar porcelain and resin teeth (Livdent FB-20 teeth by G. C. Co., Tokyo, Japan). All were of the same shape. In the static compression test, the fracture load and deformation of the artificial teeth were measured with an Instron-type universal testing machine at a cross-head speed of 1.0 mm/min. Elastic modulus, ultimate strength and absorbed energy were calculated. In the impact test, the acceleration of a falling impactor was measured with a drop impact apparatus. The load applied to the specimen was equivalent to 300N. Absorbed energy and deformation were calculated. The resin teeth showed a lower elastic modulus, higher fracture toughness and shock-absorbing ability than the porcelain teeth. Resin teeth should be selected when the first requisite is high shock-absorbing ability, and porcelain teeth should be selected when the first requisite is high masticating efficiency.

Effect of Oral Status on QOL and Depressive Mood among the Elderly.

Depression is a mental problem in elderly dental patients. The purpose of this study was to investigate the relationship between oral status and depressive symptoms among elderly patients. The authors assessed depressive symptoms among dental patients with Zungs Self Rating Depression Scale (SDS). Subjects were 220 patients (88 men and 132 women, average age 74.5yr) who visited the Gerodontic Clinic of Tokyo Medical and Dental University. The cut-off point for depression in a geriatric population is 48. A factor analysis was done, and four factors were obtained: quality of life (QOL), depressive mood, instability of emotion and sociability.The results were as follows:1. The prevalence of depressive symptoms was 5.9%.2. The SDS and depressive mood scores were significantly higher in women than in men.3. The SDS and QOL scores were significantly higher in upper edentulous patients than in other patients.4. The SDS and QOL scores were significantly higher in upper complete denture wearers than in other patients.The results suggested that residual teeth are important for good life of the elderly.

The flow properties of tissue conditioners

The tissue conditioner changes in its viscoelastic properties with time lapse after mixing. The purpose of this study was to investigate the flow of six commercial tissue conditioners (Coe-comfort, Hydro-cast, Shofu tissue conditioner, Soft-liner, Softone, Visco-gel) at 22±1°C by the parallel plate viscometer. The viscometer is to measure the spread radius of samples (a volume of 0.5cm3) between two parallel flat plates loaded by 1 kgf weight at 1, 10, 60, 100 seconds after loading had begun. Two types of measurements were taken. The first measurement consisted of mixing powder and liquid according to the manufactures recommendations, loading the sample on the viscometer, and measurements taken at 3, 5, 7 minutes after mixing had begun. The second measurement consisted of mixing powder and liquid in three varieties of powder-liquid ratios, loading the sample on the viscometer, and measurements taken at 3 minutes after mixing had begun.The findings were as follows;1. Mixing powder and liquid according to the manufactures recommendations, the spread radius decreased at 3 minutes in the following order: Hydro-cast, Shofu tissue conditioner, Viscogel, Coe-comfort, Soft-liner and Softone. The spread radius decreased at 5, 7 minutes in the following order: Hydro-cast, Visco-gel, Coe-comfort, Shofu tissue conditioner, Soft-liner and Softone.2. As the powder-liquid ratio increased, all materials were more viscous. As the powderliquid ratio decreased, all materials were more fluid.