OXYGEN PLASMA TREATMENT FOR STERILIZATION IN DENTISTRY

高压灭菌器作为一种对器械和材料进行灭菌的有效方法，已广泛应用于牙科领域。碳钢仪器的腐蚀和残留在仪器表面的分解细菌物质一直是高压灭菌器的问题。本研究的目的是探讨氧等离子体反应器作为牙科灭菌器的特性。所使用的等离子体反应器为PR-31型（YAMATO scico .）。有限公司)。通过电容耦合对玻璃腔施加13.56MHz的高频电场。腔内氧流量50ml/min ~ 100ml/min。将外径2.00mm，内径0.95mm的玻璃管插入pla sma中，用直径0.08mm的铁-康钽热电偶测量管内温度。温度随等离子体施加的输出功率和持续时间的增加而升高。实验采用5*20*0.5mm金属板作为试样。将全唾液（约10000 ~ 1000000CFU）置于标本上，干燥30min。通过脑心灌注液中培养的标本来估计其效果。300W （10min）等离子体处理后，25个标本均呈阴性培养。采用等离子体、高压灭菌器或干热灭菌对新型碳钢毛刺进行了处理。在扫描电子显微镜下对这些毛刺表面的观察显示，等离子体处理产生了最干净的表面。综上所述，氧等离子体处理具有作为牙齿灭菌剂的可能性。

The autoclave has been widely used in dentistry as an effective method to sterilize instruments and materials. Corrosion of carbon steel instruments and the decomposed bacterial substances remaining on the surface of the instruments have been the problem with the autoclave. The purpose of this study was to investigate the characteristics of an oxygen plasma reactor as the dental sterilizer. The plasma reactor used was type PR-31 (YAMATO Sci.Co.Ltd) . High frequency electric field of 13.56MHz was applied to the glass cham ber by capacitance coupling. Oxygen flow in the chamber was 50ml/min to 100ml/min.Internal temperature of a glass tube (outer diameter : 2.00mm, internal diameter : 0.95mm) inserted into the pla sma was measured by the iron-constantan thermocouple(diameter : 0.08mm) . The temperature increased in accordance with the out put power and duration of the application of the plasmaMetal plates (5*20*0.5mm) were u sed as the test specimens. Whole saliva (circa 10000 to 1000000CFU) was place d on the specimen and dried for 30min. The effect was estimated by the cult ured specimens in the brain heart infusion broth. When the plasma treatment of 300W (10min) was applied, all of the 25 specimens resulted in negative culture.New carbon steel burs were treated by plasma, or autoclave sterilization or dry heat sterilization. Obsevation of the surfaces of these burs under a scanning electron microscope revealed that plasma treatment produced the cleannest surface.In conclusion, the oxygen plasma treatment has possibility to be used as a dental sterilizer.