Biological Effects of a Root Conditioning Treatment on Periodontally Affected Teeth - An In Vitro Analysis

Abstract The aim of this study was to evaluated the root surfaces modifications resulted by application of different chemicals agents, and their influence on the fibrin network and fibroblasts attachment. From 96 anterior mandibular human extracted incisor teeth, 192 dentin blocks of buccal and lingual surface were obtained and randomly divided into 6 groups: Cont- control group, which received no treatment; Root surface scaling and root planing (Srp); Citric acid-Srp; EDTA-Srp; Tetracycline capsule-Srp; Tetracycline gel-Srp. After dentin treatments the specimens were analyzed as follows: 1) demineralization level and residues of the product by scanning electron microscopy (SEM); 2) adhesion of blood components after 20 min of surface treatment by SEM; 3) fibroblast attachment after 24 h by SEM; 4) cell metabolism after 24 h by MTT assay. Data were analyzed using Fisher Exact, One-way ANOVA test followed by Dunn's test, Tukey test and Dunnett test (α=0.05). Citric acid, EDTA and Tetracycline gel resulted in adequate demineralization with no completely smear layer and smear plug removal on root dentin surface. Tetracycline capsule produced great tetracycline residues with several demineralization areas. Tetracycline gel and EDTA groups presented more fibroblast fixation than other experimental groups. The highest mean blood clot adhesion score was observed in roots treated with tetracycline gel. EDTA and Tetracycline gel surface treatment removed the smear layer over dentin surface and promoted adhesion of fibrin network and fibroblast cells attachment.

摘要 本研究旨在评估不同化学制剂作用引发的牙根表面改变，及其对纤维蛋白网络与成纤维细胞黏附的影响。从96颗拔除的人下颌前切牙中，获取颊侧与舌侧的牙本质块共192份，随机分为6组：对照组（Cont），未接受任何处理；根面刮治及根面平整（Srp）组；柠檬酸-Srp组；乙二胺四乙酸（EDTA）-Srp组；四环素胶囊-Srp组；四环素凝胶-Srp组。牙本质标本经处理后，依次开展以下分析：1）通过扫描电子显微镜（SEM）检测脱矿程度与制剂残留情况；2）经表面处理20分钟后，通过SEM观察血液成分的黏附情况；3）培养24小时后，通过SEM检测成纤维细胞的黏附情况；4）培养24小时后，通过MTT比色法检测细胞代谢活性。数据采用Fisher确切概率法、单因素方差分析（One-way ANOVA），随后辅以Dunn检验、Tukey检验及Dunnett检验进行分析（检验水准α=0.05）。柠檬酸、EDTA及四环素凝胶可实现理想的脱矿效果，且未完全去除牙根牙本质表面的玷污层与玷污栓。四环素胶囊处理后会残留大量四环素制剂，并伴随多处脱矿区域。四环素凝胶组与EDTA组的成纤维细胞黏附数量多于其余实验组。四环素凝胶处理的牙根样本的血凝块黏附评分均值最高。EDTA与四环素凝胶表面处理可去除牙本质表面的玷污层，并促进纤维蛋白网络黏附与成纤维细胞附着。