Pang Nan-Shim, Jung Il-Young, Bae Kwang-Shik, Baek Seung-Ho, Lee Woo-Cheol, Kum Kee-Yeon
Department of Conservative Dentistry, Oral Science Research Center, Yonsei University, Yonsei, Korea.
J Endod. 2007 May;33(5):594-8. doi: 10.1016/j.joen.2007.01.019. Epub 2007 Mar 12.
The aims of this study were to identify microorganisms on the surface of gutta-percha (GP) cones using a polymerase chain reaction (PCR) and to evaluate the sterilization effect of 5.25% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), and ChloraPrep on these bacteria. Alterations of the surface texture and physical properties of GP cone after chemical sterilization were compared. A total of 150 GP cones were randomly selected in endodontic clinics, and a PCR assay was performed to identify the contaminating microorganisms. After inoculation with the same microorganisms followed by drying for 1 day, the GP cones were immersed in the three chemical disinfectants. The sterilization effects were assessed by measuring the turbidity and through subculturing. The changes in surface texture were observed by scanning electron microscopy, and Instron 5500 (Instron Corp, Canton, MA) was used to measure the tensile strength and elongation rate of the GP cones after chemical sterilization. Statistical analysis was performed. Results indicate that 19.4% of GP cones from the clinic were contaminated, and all the species belonged to the genus Staphylococcus. Three chemical disinfectants were all effective in the rapid disinfection of GP cones against Staphylococcus spp, and 1-minute immersion of the GP cones was adequate for disinfection. Microphotographs of the NaOCl-soaked cone showed a cluster of cuboidal crystals. The tensile strength between the NaOCl- and CHX-soaked groups was significantly different (p<0.05), but there was no significant difference between the NaOCl- and ChloraPrep-soaked groups (p>0.05). All disinfectants significantly increased the elongation rate of the GP cones compared with fresh GP cones (p<0.05), especially in the ChloraPrep (Medi-flex, Leawood, KS). These results show that the three chemical disinfectants are effective agents for the rapid sterilization of GP cones. However, further research will be needed to determine the clinical relevance of the changes in physical properties.
本研究的目的是使用聚合酶链反应（PCR）鉴定牙胶尖（GP）表面的微生物，并评估5.25%次氯酸钠（NaOCl）、2%氯己定（CHX）和氯普瑞（ChloraPrep）对这些细菌的杀菌效果。比较了化学消毒后GP尖表面质地和物理性能的变化。在牙髓病诊所随机选取150个GP尖，进行PCR检测以鉴定污染的微生物。接种相同微生物并干燥1天后，将GP尖浸入三种化学消毒剂中。通过测量浊度和传代培养评估杀菌效果。通过扫描电子显微镜观察表面质地的变化，并使用Instron 5500（Instron公司，马萨诸塞州坎顿）测量化学消毒后GP尖的拉伸强度和伸长率。进行了统计分析。结果表明，诊所中19.4%的GP尖被污染，所有菌种均属于葡萄球菌属。三种化学消毒剂对GP尖对抗葡萄球菌属的快速消毒均有效，将GP尖浸泡1分钟足以消毒。NaOCl浸泡的牙胶尖的显微照片显示有一簇立方形晶体。NaOCl浸泡组和CHX浸泡组之间的拉伸强度有显著差异（p<0.05），但NaOCl浸泡组和氯普瑞浸泡组之间无显著差异（p>0.05）。与新鲜的GP尖相比，所有消毒剂均显著提高了GP尖的伸长率（p<0.05），尤其是氯普瑞（Medi-flex，堪萨斯州利伍德）。这些结果表明，三种化学消毒剂是GP尖快速灭菌的有效试剂。然而，需要进一步研究以确定物理性能变化的临床相关性。
