1995 年 39 巻 5 号 p. 939-947
At present, immersion in anantiseptic solution is the most common method of sterilizing an impression. However, it is known that immersion in an antiseptic solution would have adverse effects on the accuracy and surface property of the impression. Thus it has been demanded that a sterilization method having no adverse effects on impressions be devised. In this study, the effects of impression materials on ultraviolet irradiation and those of ultraviolet irradiation on impressionswere evaluated using ultraviolet rays ith a wave length of 253.7 nm.
The results were as follows:
1. Irradiation at 7, 000μW/cm2 showed a more stable sterilization ffect than that at 1, 000 μ/W/cm2.
2. In ultraviolet irradiation at 1, 000μW/cm2 for 30 seconds, viable cells of the indicator strain were significantly less on the silicone ubber impression than on the alginate impression (p<0.01).
3. In ultraviolet irradiation at 7, 000μW/cm2 for 5, 10, 15 and 20 seconds, viable cells of the indicator strain were significantly less on the silicone rubber impression than on the alginate impression (p<0.01).
4. On observation of the impression surface after ultraviolet irradiation under scanning electron microscopy, the number of cells of the indicator strain were found to have decreased.