聚乳酸复合材料预成乳牙根管桩的基础研究

发布时间：2018-01-08 02:11

本文关键词：聚乳酸复合材料预成乳牙根管桩的基础研究　出处：《吉林大学》2014年硕士论文　论文类型：学位论文

【摘要】：在过去半个世纪中，乳牙龋病的治疗重心逐渐由拔除性治疗向修复性治疗转移。修复性治疗主要包括充填治疗、嵌体修复及金属预成冠修复。然而，在牙体组织严重缺损的病例中，牙冠修复之前，牙髓治疗和根管内固定技术是十分必要的。应用于乳牙根管内固定技术材料主要包括：金属桩核、树脂桩核、纤维桩及脱落乳牙制备的生物桩。金属、树脂和纤维桩无法被人体组织吸收，为不影响乳恒牙的正常替换，用于乳牙时多位于牙颈部1/3，这易导致材料脱落或牙根的折断等；脱落乳牙制备的生物桩虽能克服植入长度不足和牙根吸收的问题，但存在感染和排斥等潜在风险。因此，制备具有一定生物力学性能、良好的生物相容性及与乳牙根生理性吸收同步降解性能的乳牙根管桩，具有重要临床意义。本研究以NH4H2PO4、Ca（CH3COO）2H2O及CH3COONH4作为原料制备羟基磷灰石微球。按羟基磷灰石质量分数为0%、3%、5%、7%和9%，采用溶液共混法和热压成型法制备聚乳酸/羟基磷灰石复合材料。通过扫描电子显微镜(SEM)、X射线晶体衍射（XRD）及傅立叶变换红外光谱（FT-IR）检测羟基磷灰石物理化学性能；万能材料试验机测试复合材料的弯曲强度和弹性模量；MTT法检测羟基磷灰石复合材料对L929细胞相对增殖率（RGR）的影响，旨在探讨复合材料作为乳牙根管桩的可行性，为乳牙残根、残冠的临床治疗提供新的思路。结果显示：所制备的羟基磷灰石为片层状晶体所构成的微球形，直径约1μｍ，，大小均匀，形态一致，结晶度及纯度高。与单纯聚乳酸组比较，含有羟基磷灰石各复合材料组的弯曲强度和弹性模量明显增高（P0.01），羟基磷灰石质量分数为5%复合材料的弯曲强度和弹性模量达最优值（138MPa、4600MPa）。MTT法检测羟基磷灰石质量分数为0%、3%、5%、7%和9%各组复合材料RGR均在93%以上，细胞毒性级别均为0~1级。结论可知：聚乳酸/羟基磷灰石复合材料具有一定的力学性能,无细胞毒性，有望成为理想的乳牙根管桩材料。
[Abstract]:Over the past half century, the focus of the treatment of deciduous caries has gradually shifted from extubation to restorative treatment, which mainly includes filling, inlay and metal precrown repair. Pulp treatment and root canal internal fixation are very necessary in the patients with severe defect of tooth tissue before crown repair. The main materials used in primary teeth root canal internal fixation include: metal post core and resin post core. Fiber post and biological post made of deciduous teeth. Metal, resin and fiber post can not be absorbed by human tissue. In order not to affect the normal replacement of deciduous permanent teeth, most of them are located at the neck of 1/3 when used in deciduous teeth. This will easily lead to material falling off or the root of the broken, and so on; Although the biological post prepared by deciduous teeth can overcome the problems of insufficient implant length and root resorption, there are potential risks such as infection and rejection. Therefore, the preparation has certain biomechanical properties. It is of great clinical significance to have good biocompatibility and simultaneous degradation with physiologic absorption of deciduous teeth. In this study, hydroxyapatite microspheres were prepared by using NH _ 4H _ 2PO _ 4O _ 3COO _ 2H _ 2O and CH3COONH4 as raw materials. The content of hydroxyapatite was 0% or 3%. Polylactic acid / hydroxyapatite composites were prepared by solution blending and hot pressing. X-ray crystal diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were used to detect the physical and chemical properties of hydroxyapatite. The bending strength and elastic modulus of the composite were measured by universal material testing machine. The effect of hydroxyapatite composite on the relative proliferation rate of L929 cells was detected by MTT method. The aim of this study was to explore the feasibility of using the composite material as root canal post of deciduous teeth as the residual root of deciduous teeth. The results showed that the prepared hydroxyapatite was a microsphere composed of lamellar crystals with a diameter of about 1 渭 m, uniform size and uniform morphology. Compared with the pure PLA group, the flexural strength and elastic modulus of the composites containing hydroxyapatite increased significantly (P0.01). The flexural strength and elastic modulus of the composite material with hydroxyapatite content of 5% reached the optimum value: 138MPA, 4600MPA, MTT, the mass fraction of hydroxyapatite was 0%. The RGR of 7% and 9% groups of composites were above 93%, and the cytotoxic grade was 0 ~ 1. Conclusion: Polylactic acid / hydroxyapatite composite has certain mechanical properties. It has no cytotoxicity and is expected to be an ideal material for primary root canal post.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R783.1

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