口腔医学研究

口腔医学研究 ›› 2021, Vol. 37 ›› Issue (2): 118-121.DOI: 10.13701/j.cnki.kqyxyj.2021.02.006

• 牙体修复学研究 • 上一篇    下一篇

不同制备形态对短冠磨牙髓腔固位冠抗折性影响的研究

粟猛, 屈直*   

  1. 锦州医科大学附属第二医院口腔修复科 辽宁 锦州 121000
  • 收稿日期:2020-06-08 发布日期:2021-02-11
  • 通讯作者: 屈直,E-mail:quzhi7777@sina.com
  • 作者简介:粟猛(1992~ ),男,湖南常德人,硕士,住院医师,研究方向:髓腔固位冠、牙体保存。
  • 基金资助:
    辽宁省重点研发计划指导计划项目(编号:2018225031)

Effect of Preparation Designs on Fracture Strengths of Endocrown of Maxillary Short Coronal Molars

SU Meng, QU Zhi*   

  1. Department of Prosthodontics, The Second Affiliated Hospital of Jinzhou Medical University, Jinzhou 121000, China
  • Received:2020-06-08 Published:2021-02-11

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摘要： 目的:比较3种不同预备深度和有无牙本质肩领对髓腔固位冠修复体及牙体抗折性的影响,为临床上髓腔固位冠修复短冠磨牙的牙体预备提供参考。方法:收集牙颈部至根尖形态完整的上颌离体恒磨牙30颗。设置3种髓腔预备深度3 mm、4 mm、5 mm,两种边缘预备形式,随机分为6组,通过CAD-CAM技术制作氧化锆髓腔固位冠进行修复,随后进行抗折强度测试,记录折裂负荷值以及折裂模式。结果:6组样本的折裂负荷值不管是在对接组还是肩台组中,最大载荷值均为3 mm组<4 mm组<5 mm组,但组间两两比较无显著性差异。肩台组的最大载荷值大于对接组,在3 mm和4 mm组中差异性有统计学意义。6组样本折裂模式中均以不可修复折裂为主,5 mm组中均呈现不可修复性折裂。结论:通CAD-CAM技术制作的氧化锆髓腔固位冠修复上颌短冠磨牙时,3 mm和4 mm的髓腔预备深度均能满足临床抗折强度要求,但不宜超过4 mm;另外,预备形态中引入1 mm的牙本质肩领可作为临床一种有效增加牙体和修复体抗折强度的预备方式。

关键词: 髓腔固位冠, 预备深度, 牙本质肩领, 抗折性能

Abstract: Objective: To evaluate the effect of restoration design with different preparation depths and with or without ferrule on the failure load of maxillary short coronal molar restored with endocrown. Methods: Thirty permanent molars with complete morphology from the neck to the apical were collected. Three kinds of pulp cavity preparation depth, i.e. 3 mm, 4 mm, and 5 mm and two kinds of margin design were randomly divided into six groups, which were restored with zirconia endocrowns by CAD-CAM technique. The flexural strength test was recorded with the fracture load value and the fracture mode. Results: No matter the butt margin group or the shoulder group, the maximum loading value of the six groups was 3mm<4mm<5mm, however, there was no significant difference between two groups. The maximum load value of the shoulder group was greater than that of the butt margin group, and there was a statistically significant difference between the 3mm and 4mm groups. In the fracture mode of six groups of samples, irremediable fracture was the main one, and all samples in the 5mm group presented irremediable fracture. Conclution: When maxillary short coronal molars were restored with zirconia endocrowns by CAD-CAM technology, the preparation depth of pulp cavity at 3mm and 4mm could meet the requirements of clinical flexural strength, however, no more than 4mm. In addition, the introduction of 1mm dentin shoulder collar could be used as a clinical preparation method to effectively increase the flexural strength of teeth and prostheses.

Key words: endocrown, preparation depth, ferrule, fracture resistance