中国实用口腔科杂志

中国实用口腔科杂志 ›› 2025, Vol. 18 ›› Issue (4): 440-446.DOI: 10.19538/j.kq.2025.04.008

• 论著 • 上一篇    下一篇

斜面洞形设计对牙根纵裂患牙粘接后抗折力的影响研究

李慧影1a，2，王    通1b，付    静1c，郭婧涵1a，2，房志敏1a，2，许海平1a，2   

  1. 1. 青岛大学附属医院a口腔内科，b信息管理部，c口腔修复科，山东 青岛 266003；2. 青岛大学口腔医学院，山东 青岛 266023
  • 出版日期:2025-07-30 发布日期:2025-07-30
  • 通讯作者: 许海平
  • 基金资助:
    国家自然科学基金（81600903）

  • Online:2025-07-30 Published:2025-07-30

摘要： 目的    研究斜面洞形设计对牙根纵裂（vertical root fracture，VRF）粘接治疗后牙根抗折力的影响。方法    研究于2024年1—12月在青岛大学口腔医学院科研实验室进行。收集单根牛前牙64颗，截冠获得15 mm牙根样本，统一根管预备。随机选取其中60个样本用于加载实验，将其随机分3组（1个对照组和2个实验组，每组20个）。其中，对照组为完整牙根，仅充填根管；实验组劈根建立VRF模型后预备粘接面，根据预备形态分为斜面组（制备根面向根管倾斜的斜面）和平行组（不做斜面），牙科显微镜下测量预备后的粘接面积，并用树脂粘接修复裂根。于万能材料试验机垂直加载，并记录抗折力。采用Pearson相关性分析检验抗折力和粘接面积间的相关性。通过牙科显微镜观察对照组裂纹方向，并记录实验组牙体-材料粘接面的断裂模式；通过扫描电镜观察实验组牙体-材料粘接面形态。另4个样本以同样方法制备VRF模型，并按照斜面组、平行组的形态预备粘接面（每组2个），不粘接，通过扫描电镜观察其粘接面牙本质小管形态，并采用ImageJ 1.8.0测量未粘接的4个样本的牙本质小管面积占比。结果    斜面组的粘接面积明显大于平行组，差异有统计学意义（t = 5.468，P < 0.001）。各组样本的抗折力比较，差异有统计学意义（F = 6.505，P = 0.003）；进一步组间两两比较发现，平行组样本的抗折力明显低于对照组，差异有统计学意义（q = 5.099，P = 0.002），而斜面组与对照组比较差异无统计学意义（q = 2.420，P = 0.210），斜面组和平行组比较差异无统计学意义（q = 2.679，P = 0.150）。实验组样本的抗折力和粘接面积相关性分析结果显示，二者为具有统计学意义的正相关（r = 0.910，P < 0.001）。加载后实验组样本断裂模式以Ⅲ型（混合破坏）为主，斜面组剥脱材料表面存在大量树脂突，而平行组材料表面光滑；在未粘接样本的粘接面中，平行组的牙本质小管面积占比为（38.39 ± 1.60）%，明显大于斜面组［（20.42 ± 1.40）%］，差异有统计学意义（t = 19.150，P < 0.001）。结论    粘接面设计斜面洞形可增加粘接面积，增加暴露牙本质小管横断面，提高VRF粘接后牙根的抗折力。

关键词: 牙根纵裂, 粘接治疗, 意向性牙再植, 斜面洞形, 抗折力

Abstract: Objective    To investigate the fracture resistance of root with vertical root fracture（VRF）after reattachment with bevel cavity design. Methods    The study was conducted in the scientific research laboratory of School of Stomatology，Qingdao University from January to December 2024. Totally sixty-four single-rooted bovine teeth were collected. The crowns were removed to obtain 15 mm-long root samples，and the root canals were uniformly prepared. Sixty of these samples were randomly selected for the loading experiment and randomly divide into 3 groups（1 control group and 2 experimental groups，n = 20）. The control group consisted of complete roots，and only root canals were filled；in experimental groups，roots were split to establish VRF models and the bonding surfaces were prepared. According to the preparation morphology，the experimental groups were divided into two subgroups：the bevel group（with a bevel inclined towards the root canal），and the parallel group（without bevel design）. The bonding area was measured under a dental microscope after cavity preparation，and the fractured roots were bonded with resin. After bonding，the roots were fractured with a universal material testing machine and the fracture load was recorded. Pearson correlation analysis was used to test the correlation between the fracture resistance and the bonding area. The crack direction of the roots in the control group was observed under the dental microscope，and the fracture patterns of the tooth-material bonding surfaces in the experimental groups were recorded. The morphology of the tooth-material bonding surface in the experimental groups was also observed by scanning electron microscope. VRF models of another 4 roots were prepared in the same way，and the bonding surfaces were prepared according to the morphology of the bevel group and the parallel group（2 in each group），without reattachment. The morphology of the dentinal tubule on the bonding surface was observed by scanning electron microscope. The proportion of the dentinal tubule area of the 4 unattached samples was measured by ImageJ 1.8.0. Results    The bonding area of the bevel group was obviously larger than that of the parallel group，and the difference was statistically significant（t = 5.468，P < 0.001）. The comparison of fracture resistance among the groups showed statistically significant differences（F = 6.505，P = 0.003）；further pairwise comparisons between groups showed that the fracture resistance of the roots in the parallel group was obviously lower than that in the control group，and the difference was statistically significant（q = 5.099，P = 0.002）. There was no statistically significant difference between the bevel group and the control group（q = 2.420，P = 0.210），nor between the bevel group and the parallel group（q = 2.679，P = 0.150）. The analysis results of the correlation between the fracture resistance and the bonding area of the samples in the experimental groups showed that there was a positive correlation with statistical significance between the two（r = 0.910，P < 0.001）. Mixed fracture（type Ⅲ）was the main fracture mode in the experimental groups after loading. On the material de-bonding surfaces，numerous resin tags were observed in bevel group，while the surfaces of parallel group were smooth. For the bonding surfaces of the unattached samples，the proportion of dentinal tubule area in the parallel group was（38.39 ± 1.60）%，which was significantly larger than that in the bevel group［（20.42 ± 1.40）%］，and the difference was statistically significant（t = 19.150，P < 0.001）. Conclusion    The design of bevel cavity on the bonding surface can increase the bonding area and the cross-section of the exposed dentin tubules，and improve the fracture resistance of reattached root with VRF.

Key words: vertical root fracture, reattaching treatment, intentional dental replantation, bevel cavity, fracture resistance