Laboratory of Microbiology, School of Dentistry, Federal University of Pelotas, PelotasRS, Brazil.
J Appl Oral Sci. 2013 Sep-Oct;21(5):403-8. doi: 10.1590/1679-775720130184.
The aim of this study was to investigate the coronal microleakage of endodontically treated teeth prepared to receive an intracanal post and teeth with an intracanal post but without a prosthetic crown and exposed to contamination by fresh human saliva.
A mechanical-chemical preparation following the step-back technique was carried out in 35 extracted single-rooted human teeth. The teeth were randomly divided into five groups: G1=root canals instrumented, obturated, and prepared to receive an intracanal post (N=10); G2=root canals with cemented posts but without coronal sealing (N=10); PC1=positive control root canals instrumented and open (N=5); PC2=positive control 2 root canals without instrumentation and open (N=5); and NC=negative control healthy teeth (N=5). The crowns were removed except for the control group of intact teeth. The root canals were obturated and sterilized with cobalt 60 gamma irradiation and were then adapted in an apparatus using a Brain Heart Infusion (BHI) medium and fresh human saliva for contamination. Microbial growth was indicated by the presence of turbidity in the BHI liquid medium.
Data were submitted to the Kaplan-Meier Survival Analysis and the Holm-Sidak statistic method, which observed an index of 90% of microleakage in root canals after 24 hours for G1 and 70% of microleakage in samples at the end of 40 days for G2.
The results show that root canals with an intracanal post but without a prosthetic crown can be recontaminated when exposed to fresh human saliva in a short period.
本研究旨在调查接受根管内桩和无修复体冠但暴露于新鲜人唾液污染的根管内桩的根管治疗牙的冠向微渗漏情况。
对 35 颗离体单根人牙进行机械-化学预备，采用逐步后退技术。将牙齿随机分为五组：G1=根管预备、根管充填并预备接受根管内桩（N=10）；G2=根管内有粘结桩但无冠部密封（N=10）；PC1=阳性对照开髓不预备根管（N=5）；PC2=阳性对照 2 个不预备开髓根管（N=5）；NC=阴性对照健康牙（N=5）。除完整牙的对照组外，去除牙冠。根管用钴 60γ射线照射进行充填和消毒，然后在装置中用 Brain Heart Infusion（BHI）培养基和新鲜人唾液适应以进行污染。BHI 液体培养基中出现浑浊表明存在微生物生长。
数据采用 Kaplan-Meier 生存分析和 Holm-Sidak 统计方法进行分析，观察到 G1 组在 24 小时后有 90%的根管微渗漏，G2 组在 40 天结束时有 70%的样本有微渗漏。
结果表明，在短时间内，暴露于新鲜人唾液的根管内桩但无修复体冠的根管可能会再次受到污染。
