人体天然牙及牙科修复材料冲击磨损行为的体外试验研究

发布时间：2017-12-31 10:37

本文关键词：人体天然牙及牙科修复材料冲击磨损行为的体外试验研究　出处：《西南交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：牙齿是人体重要的咀嚼器官,在中枢神经系统的支配下,以咀嚼肌为动力,(?)为程序,周而复始进行咀嚼循环。在咀嚼过程中,上下对颌牙在咬合力的作用下发生冲击加载和切向滑动,从而对食物进行切割、粉碎和磨细等系列机械加工。上下对颌牙在咬合力作用下的冲击接触和滑动摩擦导致牙(?)面发生冲击磨损和滑动磨损,通常临床上观察到的牙齿咬合面磨损是冲击磨损和滑动磨损共同作用的结果。因此,开展人牙冲击磨损的相关研究,以便全面深入了解人体天然牙的磨损机制,为临床防治牙齿过度磨损和研发新型牙科修复材料提供理论依据。本文采用小载荷冲击磨损试验机,使用显微硬度仪、扫描电子显微镜、激光共聚焦显微镜、表面轮廓仪等分析测试设备,研究了人牙的冲击磨损行为以及牙齿中水分对牙齿冲击磨损行为的影响,此外,对比考察了人牙与两种常见牙科修复材料钛合金和合成羟基磷灰石的冲击磨损行为。旨在全面深入了解人牙冲击磨损机制及磨损特性。取得的主要结果和结论如下： (1)人体天然牙冲击磨损体积随循环次数的增加呈非线性增大,在磨损初期,人牙表面呈现轻微塑性变形；随着冲击次数增加,磨损表面出现剥落,磨损加剧；在冲击力的反复作用下剥落下来的釉质磨屑尺寸逐渐变小,在磨损表面形成磨屑层,磨损速率降低,磨斑剖面未产生裂纹。牙齿中水分对牙齿的冲击磨损行为具有一定影响。随着干燥时间增长,牙齿表面断裂韧性降低,更容易发生剥落,磨屑层形成时间减小,磨损速率更快的减缓,磨斑剖面产生裂纹。 (2)钛合金和合成羟基磷灰石冲击磨损体积均随循环次数的增加呈非线性增大,在冲击过程中,钛合金磨斑剖面未产生裂纹,合成羟基磷灰石磨损表面未产生硬化,磨斑剖面出现微裂纹。 (3)同脆性的合成羟基磷灰石相比,人牙冲击磨损行为更接近韧性的钛合金。
[Abstract]:The tooth is an important human organ of mastication, in the control of the central nervous system, with masticatory muscle power, (?) for the program, and for chewing cycle. During chewing, upper and lower jaw in bite force under impact loading and tangential sliding, so as to cut food, crushing a series of machining and grinding. Upper and lower jaw in bite force under the action of impact contact and sliding friction cause tooth surface (?) impact wear and wear, usually observed in clinical tooth occlusal surface wear is the impact wear and sliding wear together. Therefore, to carry out related research the impact of tooth wear, in order to in-depth understanding of the wear mechanism of human tooth, and provide a theoretical basis for clinical prevention and treatment of excessive tooth wear and the development of new dental restorative materials.
The small load impact wear testing machine, using microhardness tester, scanning electron microscope, laser confocal microscopy, surface profiler analysis and test equipment, water impact, impact wear behaviors of human tooth and tooth wear behavior of tooth impact in addition, were investigated and compared with two common dental dental restoration titanium alloy and hydroxyapatite impact wear behavior. In order to understand human tooth impact wear mechanism and wear characteristics. The main results and conclusions are as follows:
(1) the impact of human tooth wear volume increase nonlinearly with the increase of the cycle number in the early human tooth surface abrasion, slight plastic deformation; with the increase of impact times, wear surface spalling and wear; in the repeated impact by peeling off the enamel debris size becomes smaller, the wear the surface of the formation of debris layer, the wear rate decreased, the worn profile without cracks. The moisture in the teeth on the tooth impact wear behavior has certain influence. As the drying time increases, reduce the tooth surface and fracture toughness, more prone to spalling, debris layer formation time decreases faster wear rate slowed down, the worn profile produced crack.
(2) the impact wear volume of titanium alloy and hydroxyapatite increases linearly with the increase of cycle times. During the impact process, there is no crack in the grinding spot section of titanium alloy. The hydroxyapatite wear surface does not harden, and the micro cracks appear on the worn spot.
(3) compared with the brittle synthetic hydroxyapatite, the impact wear behavior of the human teeth is closer to the toughness of the titanium alloy.

【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R783.1

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