As part of a study of the disinfection of impressions in the dental treatment of elderly patients at home, the present study investigated the effect of long-term storage of alginate impressions in sealed bags on the dimensional accuracy and deformation of stone models in order to evaluate the possibility of storage of impressions following spray with disinfectant solutions.
Eleven brands of alginate impression materials were measured to determine the dimensional changes in 100% relative humidity for 4 hours. Among the brands showing little dimensional change, 3 brands were chosen as test materials to investigate the effect of storage of impressions in sealed bags on the dimensional accuracy and deformation of stone models. The periods for storage of impressions were 2,3, and 4 hours. The stone models obtained from non-stored impressions were also prepared as controls.
The results were summarized as follows:
1. All 11 brands of alginate impression materials showed a tendency to contract in 100% relative humidity over time. However, the amounts of dimensional changes of impressions in 100% relative humidity for 4 hours varied with each brand.
2. When an alginate impression material with a small dimensional change in 100% relative humidity for 4 hours was used for impression taking, the storage of the impression in a sealed bag for 4 hours had little effect on the dimensional accuracy and deformation of stone models.

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The purpose of this study was to determine the relationship between Pulse Wave Velocity (PWV) and hemodynamic change induced by postural change on dental chair in bed-ridden elderly.
20 patients with cardiovascular diseases, scheduled to receive bloodless dental treatment were selected as the subjects of the study. Subjects were divided into two groups: 10 cases of group N (mean value for each age ≥±1×Standard Deviation) and 10 cases of group H (mean value for each age≥±1×Standard Deviation) based on resting brachial-ankle PWV (baPWV).
ABI-form^TM was used for measurement of PWV. Posture was changed from horizontal position to sitting position before the start of dental treatment. Blood pressure and pulse rate were measured continuously.
As the result, both groups did not show significant differences in terms of age, sex, blood pressure and pulse rate except for baPWV. Both groups showed significant decrease of systolic blood pressure and diastolic blood pressure when the posture was changed from horizontal position to sitting position. Furthermore, systolic blood pressure was significantly different between group N (123.4±17.5 mmHg) and group H (107.7 ± 18.1 mmHg) during sitting position.
There was significant difference in recovery time between group N (94.0±24.5 seconds) and group H (169.0±40.1 seconds).
Both groups did not show significant differences in pulse rate during the postural change. Difference of pulse rate between these groups was not significant also.
This study indicated the fact that physiological increase of pulse rate along with decrease in blood pressure was not likely to occur for bedridden people unlike the cases for normal subjects. This fact indicates the necessity of close attention to the decrease in blood pressure not only during dental treatment, but also during postural change.
This study suggested that in the case of bedridden people, baPWV is related to the hemodynamic change induced by postural change, thus it can be an effective index for prediction of hemodynamic change.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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