【作者】 李平；

【导师】 肖丽英；

【作者基本信息】 四川大学 ， 口腔临床医学， 2005， 硕士

【摘要】 目的 新型纳米羟基磷灰石根充糊剂(n-HA)是一种新型生物材料,由纳米羟基磷灰石粉末、碘仿、硅油等组成。本实验就n-HA应用于临床前进行一系列基础研究,实验方案设计分为四部分。 方法 第一部分:“n-HA抑菌效能的体外研究”。采用常规打孔法,选用感染根管中的优势菌牙龈卟啉单胞菌(P. gingivalis)、具核梭杆菌(F. nucleatum)、中间普氏菌(P.intermedius)作为实验菌株,通过测量培养基上抑菌环的直径评价材料的抑菌效能。第二部分:“n-HA的细胞毒性试验”。采用MTT比色法,以F-12培养基为对照,选用n-HA 3种不同浓度的材料浸提液,分别检测浸提液与成骨细胞接触1d、3d、5d、7d的相对细胞增殖率(RGR),以评价材料的细胞毒性。第三部分:“n-HA根尖封闭性能的研究”。采用染料渗人法检测离体单根管牙在模拟临床根充环境下出现根尖微渗漏的情况。第四部分:“n-HA动物体内根管充填及颌骨和皮下埋植实验的研究”。选取3只恒牙完全萌出的犬为实验对象,更多还原

【Abstract】 Objective Nano-hydroxyapatite root canal sealer is a new biomaterial, it’s made up of nano-hydroxyapatite,iodoform and silicon oil,et al. In this study we had done a series of basic experiments before it is for clinical use as a root canal filling sealer .Method The systematic researches were divided into four parts: Part one "The antibacterial activites of n-HA in vitro ". The flat drill method were used ,and AH-plus as control, to study the antibacterial ability to P.gingivalis, F.nucleatum and P.intermedius, which were the high rate detected bacteria in infacted root canals. Part two "Evaluation on Cytotoxicity of nano- hydroxyapatite in vitro " In this study , the cytotoxicity was evaluated by the MTT method and the activity of ALP with mouse osteoblast. Part three "Evaluation on the apical sealing ability of n-HA in vitro." 34 single-rooted human teeth were instrumented. They were randomlydivided into 2 groups of 15 teeth each and filled using lateral condensation with one of the two test sealers (AH-plus, n-HA) and gutta-pertha. Another 2 groups as positive and negative controls (2 teeth each). The apical leakage was measured by dye penetration method. Part four "biocompatibility of n-HA on experimential animial in vivo".Three dogs were used and AH-plus was as control ,each dog was used for three experiments of root canal filling, mandibula implanting and subcutaneous implanting , the animals were killed after 2,4 and 12 weeks separately. The tissue reaction was assessed by X-ray and histological examination.Result ?From the diameter of the antibacterial annulus,n-HA showed more stronger antibacterial ability to three test baterials than AH-Plus..(2)With the culture time increasing the toxicity graduation of the nHA tends to 0. The cell survival rate of n-HA showed high relatively .The OD value of cell was similar to the negative control (P > 0.05 ) .(3)A11 root canal sealers tests showed some apical microleakage.AH-plus was better than n-HA,no significant difference was found between two test materials(p>0. 05).?Animal experiment showed no or merely a mild inflammatory reaction detected in specimens of n-HA,while AH-plus initiated a middling inflammatory reaction to tissue.Conclusion n-HA showed good biocompatibility than AH-plus in vivo, no cytotoxicity with the testcells, good antibacterial effect to P.gingivalis, F.nucleatum and P. intermedius,. a certain extent apical root canal sealing ability.Based on these findigs, n-HA had showed some ability,which Satisfied the need of root canal filling sealer.Futher researches are n eeded to bring more explicit insights into the properties of this material,and make better use of it.更多还原