肩台宽度对全解剖式二氧化锆冠抗压缩破坏力的影响

发布时间：2018-09-01 09:40

【摘要】：目的:本实验旨在研究CAD/CAM技术条件下,不同的肩台宽度对全解剖式二氧化锆冠抗压缩破坏力的影响,以及模拟口腔冷热微环境的冷热循环实验前后全锆冠的抗压缩破坏力有无变化,从而为临床的牙体预备、加工厂的修复体制作以及全锆冠的推荐使用年限提供依据。方法:1金属代型的制作通过基牙的设计软件Abutment Designer对日进齿科标准下颌第一磨牙进行基牙扫描,参考《口腔修复学》教材中的基牙预备原则进行基牙设计。基牙的预备标准为:鄈面功能尖磨除1.5mm,非功能尖磨除1.0mm,轴面聚合度为8°,刃状或平龈浅凹直角肩台,各部位无倒凹、无应力集中区。根据实验设计肩台宽度分别为刃状、0.3mm、0.5mm、1.0mm。将设计好的预备体3D模型数据传输给CAD切割机,选择专用的铸造蜡以1:1的比例加工24个预备体蜡型,常规包埋、铸造、打磨、喷砂完成金属代型的制作。2修复体的制作将24个金属代型用橡皮泥固定在扫描仪观测台上,扫描出预备体的3D模型,随即将数据导入到Dental Designer软件,系统会自动生成下颌第一磨牙的标准解剖形态的修复体。根据实验需要利用虚拟调改刀修整至鄈面厚度为均匀的1.0mm厚度,冠边缘处与金属代型的肩台平滑相接。即全锆冠的肩台处冠的厚度分别为刃状、0.3mm,0.5mm,1.0mm,然后把所得到的数据传递给CAD切割机。完成全锆冠的制作。具体分组:鄈面厚度1.0mm,刃状肩台、0.3mm、0.5mm、1.0mm各6个分别定为A、B、C、D组。用D组的代型再制作出一组钴铬烤瓷冠,E组作为作为对照组。全部试件用3M玻璃离子粘接于代型上。用万能实验机测量断裂时的抗压缩破坏力。统计学分析后选择肩台宽度为0.5mm组进行冷热循环实验。即鄈面厚度1.0mm,肩台宽度0.5mm组再制作18个全锆冠修复体,依据不同的冷热循环次数分为三组,分别为C1、C2、C3。3冷热循环实验将C1、C2、C3进行冷热循环实验,循环次数分别为10000次、20000次、30000次。实验参数:5℃和55℃的恒温水箱中各浸泡30s,间隔5s,冷热交替直至达到预计次数。4抗压缩破坏力实验将制作完成的全锆冠及钴铬烤瓷冠用3M玻璃离子分别粘固于相应金属代型上,指压就位,以15Kg的力持续加压5min,去除多余的粘固剂,室温静置24小时后备用。将粘结好的全冠按顺序依次置于万能试验机上进行强度测试,加载头以0.5mm/s的恒定速度加载于全冠的功能尖上,直至全冠破坏为止,记录数值。5统计学分析使用SPSS13.0软件对数据进行统计学分析。Kolmogorov-Smirnov和Shapiro-Wilk检验数据是否符合正态性分布(ɑ=0.1)。Levenes test对数据进行方差齐性检验(ɑ=0.1)。在本次实验中数据均满足正态性及方差齐性检验(P0.1),实验数据可以用均数±标准差表示(SX±)。用单因素方差分析比较不同肩台宽度全锆冠的抗压缩破坏力有无组间差别,若组间有差别再用Student-Newmen-Keuls进行组间的两两比较。P0.05认为有统计学意义。结果:1各组全冠的抗压缩破坏力A 组:(3855.00 ± 305.47)N,B 组:(2731.70 ± 261.80)N,C 组:(3698.30± 276.87)N,D 组:(3841.70± 544.88)N,E 组:2992.17± 168.41 N,C1 组:(3220.00 ± 504.38)N,C2 组:(3148.33 ± 425.60)N,C3 组:(3572.00± 545.30)N。2肉眼观察对所有的42例全锆冠样本进行宏观观察分析。所有全锆冠的实验试件均为全瓷层的断裂,裂纹走向具有相似性。首先出现在加载点的下方,然后从加载点向外延伸。主要裂纹走向有两种:沿功能尖的边缘嵴裂成两部分(20例);沿功能尖的牙尖嵴裂开(17例),其余无特殊规律(5例)。钴铬烤瓷冠的破坏为瓷层的破坏与剥脱。3统计学分析各组实验数据均符合正态性及方差齐性,5组全冠的抗压缩破坏力进行单因素方差分析:各组间的抗压缩破坏力有统计学意义(P0.05),即组间存在差异。进行组间的两两比较,B组、E组与A组、C组、D组之间差异有统计学意义(P0.05)。而B组、E组之间差异无统计学意义,A组、C组、D组之间差异也没有统计学意义。相同肩台宽度(0.5mm组),在冷热循环10000次、20000次、30000次后,其抗压缩破坏力没有统计学差异。结论:1通过与鄈面厚度为1.5mm的钴铬烤瓷冠强度对比表明,对于鄈面厚度为1.0mm的全锆冠而言,无论是刃状还是0.3mm或以上的肩台均可满足临床的需要。2冷热循环次数对全锆冠抗压缩破坏力没有影响(限于本实验30000次以内)。
[Abstract]:OBJECTIVE: To study the effects of different shoulder widths on the compression resistance of fully dissected zirconia crowns under CAD/CAM conditions, and whether the compression resistance of the full-dissected zirconia crowns has changed before and after the cold-hot cycling test in simulated oral cold and hot microenvironment, so as to prepare Clinical teeth, fabricate prosthetic system of the processing factory and Methods: 1. The metal substitution was made by Abutment Designer to scan the mandibular first molars, and the abutment teeth were designed according to the principle of abutment teeth preparation in the textbook of prosthodontics. According to the experiment, the width of shoulder platform is designed as edge, 0.3 mm, 0.5 mm, 1.0 mm. The 3D model of the prepared body is transmitted to CAD cutter, and the special casting wax is selected to process 24 preparations in 1:1 ratio. Body wax, routine embedding, casting, grinding, sandblasting complete the production of metal substitutes. 2 Prosthetic production of 24 metal substitutes with rubber mud fixed on the scanner observatory, scanned the 3D model of the reserve, and then imported the data into Dental Designer software, the system will automatically generate the restoration of the standard anatomical form of the first mandibular molar. The crown edge of the zirconium crown is smoothly connected with the shoulder platform of the metal model. The thickness of the crown at the shoulder platform of the zirconium crown is 0.3 mm, 0.5 mm, 1.0 mm respectively, and then the obtained data is transmitted to the CAD cutter. The whole zirconium crown is made. Specific grouping: 1. Group A, B, C and D were made with the substitutes of group D. Group E was used as the control group. All the specimens were bonded with 3M glass ions to the substitutes. Eighteen zirconium crowns were fabricated in group 1.0 mm thick and 0.5 mm wide, and were divided into three groups according to the number of cycles: C1, C2 and C3.3. The cycles of C1, C2 and C3 were 10 000, 20 000 and 30 000, respectively. The zirconium crowns and cobalt-chromium porcelain crowns were bonded to the corresponding metal substitutes by 3M glass ions respectively in the constant temperature water tank for 30 seconds, 5 seconds apart, alternating heat and cold until the expected number of times was reached. Bonded crowns were placed sequentially on the universal testing machine for strength testing. The loading head was loaded on the functional tip of the crown at a constant speed of 0.5mm/s until the crown was destroyed. The recorded values were statistically analyzed using SPSS13.0 software. Kolmogorov-Smirnov and Shapiro-Wilk were used to test whether the data were true or not. Levenes test was used to test the data for the homogeneity of variance (_ = 0.1). In this experiment, the data were all tested for the homogeneity of normality and variance (P 0.1). The experimental data can be expressed by mean (+) standard deviation (SX (+). The compressive failure resistance of full zirconium crowns with different shoulder widths was compared by one-way ANOVA. P 0.05 showed that there was statistical significance. Results: 1 The anti-compression destructive power of all crowns in group A: (3855.00 (+305.47) N, group B: (2731.70 (+261.80) N, group C: (3698.30 (+276.87) N, group D: (3841.70 (+544.88) N, group E: 2992.17 (+168.41), group C1: (3220.00 (+50.50). 4.38) N, C2 group: (3148.33 + 425.60) N, C3 group: (3572.00 + 545.30) N. There were two kinds of fracture: the marginal ridge of the functional cusp was divided into two parts (20 cases), the ridge of the functional cusp was split (17 cases), and the rest had no special rule (5 cases). The destruction of the cobalt-chromium porcelain crown was the destruction and exfoliation of the porcelain layer. Analysis: There were significant differences in the anti-compression destructive power among groups (P 0.05), that is, there were differences between groups. There were significant differences between groups B, E and A, C and D (P 0.05). There was no significant difference in the compressive destructive force between the two groups after 10 000 cycles, 20 000 cycles and 30 000 cycles. Conclusion: 1. Comparing with the strength of cobalt-chromium porcelain crowns with 1.5 mm of VI thickness, the edge-shaped or 0.3 mm or more of the full zirconium crowns with 1.0 mm of VI thickness can meet the clinical needs. It has no effect on the compressive strength of all zirconium crown (limited to 30000 times in this experiment).
【学位授予单位】：河北医科大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：R783.3

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