Department of Dentistry, School Integrated of Diamantina, FAFEID, Minas Gerais, Brazil.
J Appl Oral Sci. 2005 Mar;13(1):93-100. doi: 10.1590/s1678-77572005000100019.
In the endodontic treatment of root canals with necrotic pulps associated with periapical radiolucent areas, one of the main objectives of treatment consists in eliminating the microorganisms spread throughout the ramifications of the root canal system. The scope of this study was to evaluate the antiseptic efficacy of biomechanical preparation and two calcium hydroxide-based pastes, in dogs' teeth with experimentally induced chronic periapical lesions. After initial microbiological sampling, instrumentation of the root canals was undertaken using the conventional technique, using K type files used in conjunction with a solution of 5.25% sodium hypochlorite. After ninety-six hours, further microbiological sampling was undertaken and Calen/CPMC or Calasept pastes were applied for 15 and 30 days. Ninety six hours after the removal of the medication, the third microbiological sampling was undertaken and finally histomicrobiological analysis followed using Brown & Brenn staining. The results were analyzed using the Kruskall-Wallis test, with a level of significance established at 5% (p<0.05). It was shown that the biomechanical preparation significantly reduced the number of colony forming units of microorganisms in root canals. In contrast, there was no significant difference between the antiseptic action of long-term dressings over two periods of action, although 30 days produced a greater reduction in the quantity of microorganisms and of positive microbiological cultures. In histological sections of the four experimental groups, similar microbiological patterns were shown (p>0.05), characterized by an elevated incidence of cocci, bacilli and filaments, predominantly gram-positive, in root canals, secondary canals and accessories, apical cementoplasts and dentinal tubules, but with a low incidence of microorganisms in areas of cementum resorption and the periapical lesion. The biomechanical preparation and intracanal dressing based on calcium hydroxide were important in the antisepsis of the root canal; however, both procedures did not produce significant changes in the microbiological aspects of the root canal system.
在牙髓坏死伴有根尖透光区的根管治疗中，治疗的主要目标之一是消除遍布根管系统分支的微生物。本研究的目的是评估生物力学预备和两种基于氢氧化钙的糊剂在患有实验性慢性根尖病变的犬牙中的消毒效果。初始微生物采样后，使用常规技术对根管进行器械处理，使用 K 型锉与 5.25%次氯酸钠溶液联合使用。96 小时后，再次进行微生物采样，并在 15 和 30 天内应用 Calen/CPMC 或 Calasept 糊剂。用药去除 96 小时后，进行第三次微生物采样，最后使用 Brown&Brenn 染色进行组织微生物学分析。使用 Kruskal-Wallis 检验分析结果，置信水平设为 5%（p<0.05）。结果表明，生物力学预备可显著减少根管中微生物的菌落形成单位数量。相比之下，两种长期敷料在两段作用时间内的消毒作用没有显著差异，尽管 30 天的作用可使微生物数量和阳性微生物培养物的数量减少更多。在四个实验组的组织学切片中，显示出相似的微生物模式（p>0.05），特征为根管、副根管和附件、根尖牙骨质和牙本质小管中球菌、杆菌和丝状菌的发生率较高，主要为革兰氏阳性菌，但在吸收性牙骨质和根尖病变区域中微生物的发生率较低。生物力学预备和基于氢氧化钙的根管内敷料在根管消毒中很重要；然而，这两种程序都不会对根管系统的微生物学方面产生显著影响。
