口腔医学研究

口腔医学研究 ›› 2021, Vol. 37 ›› Issue (4): 325-329.DOI: 10.13701/j.cnki.kqyxyj.2021.04.011

• 口腔修复学研究 • 上一篇    下一篇

不同粘接间隙对CAD/CAM PMMA暂时修复体固位力的影响

罗有成, 赵健, 杨双, 吴哲*   

  1. 广州医科大学附属口腔医院修复科·广州医科大学附属口腔医院·广州口腔疾病研究所·口腔医学重点实验室 广东 广州 510140
  • 收稿日期:2020-08-25 发布日期:2021-04-15
  • 通讯作者: *吴哲,E-mail:zhewudentist@gzhmu.edu.cn
  • 作者简介:罗有成(1990~ ),男,江西九江人,医师,硕士,研究方向:口腔数字化修复。
  • 基金资助:
    广州医科大学高水平大学临床研究提升计划资助课题(编号:201716019)广州市卫生健康科技项目(编号:20181A011104)

Effect of Cement Space on Retention of CAD/CAM PMMA Provisional Crowns

LUO Youcheng, ZHAO Jian, YANG Shuang, WU Zhe*   

  1. Department of Prosthodontics, Guangzhou Medical University, Key Laboratory of Oral Medicine, Guangzhou Institute of Oral Disease, Stomatology Hospital of Guangzhou Medical University, Guangzhou 510140, China
  • Received:2020-08-25 Published:2021-04-15

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摘要： 目的: 探讨设置不同粘接间隙参数对CAD/CAM PMMA全冠的固位力的影响。方法: 选取5颗因正畸需要拔除的第一前磨牙作为研究对象,按全冠牙体预备标准进行牙体预备。使用口腔扫描仪(CS3600)和Exo-cad 软件完成全解剖PMMA全冠的设计,依照设置粘接剂间隙参数不同分为6组。距离修复体终止线2 mm内粘接间隙 0 μm,终止线2 mm以上粘接间隙分别设置为20 μm、40 μm、60 μm,记为0-20组、0-40组、0-60三组;距离修复体终止线2 mm内粘接间隙 20 μm, 终止线2 mm以上粘接间隙分别设置为20 μm、40 μm、60 μm,记为20-20 组、20-40组、20-60三组。使用椅旁切削机完成PMMA全冠制作(n=30)。通过触觉-视觉表初步评估修复体的边缘适合性和稳定性;使用体式显微镜测量边缘间隙值;万能实验机进行拉伸实验检测固位力,使用SPSS 19.0统计软件对数据进行分析。结果: 针对不同粘接间隙参数,PMMA的全冠平均边缘间隙均符合临床要求。其中,0-20组平均边缘间隙最大(83±6) μm,20-60组平均边缘间隙最小(37±5) μm(P＜0.05),边缘间隙与粘接间隙呈负相关。不同粘接间隙参数的设置,PMMA全冠固位力存在统计学差异(P＜0.05)。其中,20-20组固位力最大(61±6) MPa,0-60组固位力最小(39±5) MPa(P＜0.05)。结论: 粘接间隙设置为20~20 μm时,CAD/CAM PMMA全冠修复体的固位力和稳定性可以达到满意效果。

关键词: 计算机辅助设计/计算机辅助制造, 粘接间隙, 边缘间隙, 聚甲基丙烯酸甲酯, 暂时修复体

Abstract: Objective: To explore the effect of cement space on the retention of CAD/CAM PMMA provisional crown. Methods: Five first premolars extracted for orthodontics were selected and prepared according to the standard of full crown tooth preparation. Intraoral scanner (CS3600) and Exo-cad software were used to complete the design of full anatomical PMMA crown. The samples were divided into 6 groups according to the setting of cement space. Among them, the cement space within the finish line 2 mm was 0 μm, and the cement space above the finish line 2 mm was set to 20 μm, 40 μm, and 60 μm, respectively, which were named as group 0-20, group 0-40, and group 0-60. The cement space within the finish line 2 mm was 20 μm, and the cement space above the finish line 2 mm was set to 20 μm, 40 μm, and 60 μm, respectively, which were named as group 20-20, group 20-40, and group 20-60. PMMA full crowns were made by chair side milling machine (n=5, N=30). The marginal suitability and stability of the restoration were evaluated by tactile-visual evaluation. The edge gap was measured by stereo zoom microscope. The retention force was detected by tensile test with a universal testing machine. The data were analyzed by SPSS 19.0 statistical software. Results: With the setting of different cement space parameters, the average marginal gap of the CAD/CAM PMMA crowns (P＜0.001) met the clinical requirements. Among them, the average marginal gap of group 0-20 was the largest (83±6) μm, and the mean marginal gap of group 20-60 was the smallest (37±5) μm (P<0.05). There was a negative correlation between marginal gap and cement space. There was significant difference in the retention of PMMA full crown with different cement space parameters. Among them, the retention force of group 20-20 was the highest [(61±6) MPa] and group 0-60 was the lowest [(39±5) MPa]. Conclusion: The retention and stability of CAD/CAM PMMA full crown restoration can achieve satisfactory results when the cement space is set to 20-20 μm.

Key words: computer aided design/computer aided manufacture, cement space, marginal gap, poly(methyl methacrylate), provisional restoration