Biomedical subjects

J Furuya

Publications and source records attributed to J Furuya.

3 recordsLinked to original sources

PubMed1999

[Effects of wearing complete dentures on swallowing in the elderly].

The purpose of this study was to evaluate effects of wearing complete dentures on swallowing in the elderly. Sixteen nondysphagic edentulous volunteers (mean age: 75.0 yrs) were studied in terms of surface electromyography of the anterior belly of digastrics and masseter muscles, tongue pressure toward the hard palate, and the laryngeal movement. The subjects swallowed 2 ml water under four conditions, with upper and lower dentures, without lower denture, without upper denture, and without upper and lower dentures. Dipper-type of swallowing was prescribed. A repeated-measures ANOVA was used for statistical analysis. Total swallowing duration and the latent period until laryngeal elevation were significantly prolonged without upper or lower denture, and without both dentures (p < 0.05). They were significantly shorter without lower denture than those without upper denture, and without both dentures (p < 0.05). Duration of the preparatory stage was significantly prolonged without upper denture, and without both dentures comparing with the others (p < 0.05). Duration of the oral stage was significantly prolonged without upper denture, and without both dentures comparing with the duration with both dentures (p < 0.05). There were no changes in the pharyngeal stage with or without dentures. The prolongation of total swallowing duration was due to the prolongation of the preparatory and oral stages. The prolongation of swallowing would affect the oral-pharyngeal coordination of swallowing, and exacerbate the depression of swallowing functions with aging. These results suggested that wearing complete dentures contributes to maintain physiological procedure of swallowing in the elderly.

Aged↗

PubMed1998

In vitro testing of a denture cleaning method using ozone.

The purpose of this study was to compare the microbicidal effect of gaseous ozone with that of ozonated water in order to determine its usefulness as a method for disinfecting dentures. Although a large number of research studies have been done on the bactericidal effect of ozone, little is known about its microbicidal effects on oral microorganisms. Therefore, we tested the effect of ozone on three standard strains of oral microorganisms: Streptococcus mutans (strain IID 973), Staphylococcus aureus (strain 209-P), and Candida albicans (strain LAM 14322). When the gaseous ozone injection method was used, the numbers of cells of all three strains decreased to 1/10(5) at 1 min, and by 3 min they were below the detection limit. Thus, the microbicidal effect of gaseous ozone was ascertained in a short time. In contrast, when ozonated water at 1 ppm and 3 ppm was used, C. albicans decreased to 1/10. A 700 mg/h ozone production level was needed to prepare 1 ppm ozonated water, whereas 20 mg/h of ozone was required by the gaseous ozone generator. These findings indicate that direct exposure to gaseous ozone seems to be a more effective microbicide compared with ozonated water, and that gaseous ozone can be clinically useful for disinfection of dentures.

Candida albicans↗

PubMedDate not supplied

Influence of ozone on oxidation of dental alloys.

PURPOSE: The purpose of this study was to examine the influence of ozone on the surface of removable partial denture (RPD) alloys to determine its usefulness as a cleaning method for RPDs, since ozone has powerful sterilizing and deodorizing properties. MATERIALS AND METHODS: Two types of ozone cleaning were used. The quantities of ozone generated by both methods were the same (20 mg/h). In method A, ozone was generated for 10 minutes every 12 hours and in method B, ozone was generated over 24 hours a day. Test specimens of 3 types of dental alloy (Co-Cr, Au-Ag-Pt, and Au-Cu-Ag-Pd) were subjected to different cleaning methods for 7 days and measured in terms of reflectance, surface roughness, and weight. Five different cleaning solutions (three commercial denture cleaners, acid-electrolyzed water with a pH of 2.4, and pure water) were used for comparison with the ozone treatments. RESULTS: No significant changes were detected after treatment of the Co-Cr and Au-Ag-Pt alloys with ozone. Ozone caused a slight change in the Au-Cu-Ag-Pd alloy in terms of reflectance, but the changes were significantly less than those caused by acid-electrolyzed water and one of the commercial denture cleaners. CONCLUSION: Ozone had little influence on the oxidation of dental alloys.

Chromium Alloys↗