Meyerson Danielle, Li Fang-Chi, Kishen Anil
Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.
Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.
J Endod. 2025 Jan;51(1):78-84. doi: 10.1016/j.joen.2024.11.002. Epub 2024 Nov 9.
The traditional endodontic cavity (TEC) facilitates canal preparation, but may increase susceptibility to root fracture; conservative endodontic cavities (CEC) aim to preserve tooth structure to maintain the structural integrity of root-filled teeth. The objective of this study was to evaluate the effect of access cavity design and the degree of pulp chamber root removal on the microstrain distribution patterns under different levels of functional loading using digital moiré interferometry.
Twelve extracted human teeth (n = 12) were included, comprising of mandibular premolars (n = 6) and mandibular first molars (n = 6). Specimens were subjected to physiologic levels of compressive loading ranging from 10 to 50 N for each group. Digital moiré interferometry fringe patterns were acquired three times for each pecimen: prior to endodontic cavity preparation (control group (CG)), after conservative endodontic cavity preparation (CEC), and following traditional endodontic cavity preparation (TEC). The acquired fringe patterns were used to determine the microstrain distribution at the coronal and cervical dentin. The data were analyzed qualitatively and quantitatively using one-way ANOVA and T-tests (P < .05).
The intact crowns of CG teeth showed significantly less microstrain, when compared to CEC and TEC with a distinct shift in coronal microstrain in both CEC and TEC groups. There were significant differences between both the coronal and cervical microstrain in the CG, CEC, and TEC groups.
The roof of the pulp chamber contributes to a distinct biomechanical response in posterior teeth. The microstrain at the coronal and cervical level increased significantly following de-roofing of the pulp chamber in both CEC and TEC groups, with the TEC resulting in higher coronal microstrain compared to CEC group.
传统牙髓腔（TEC）便于根管预备，但可能会增加牙根折裂的易感性；保守牙髓腔（CEC）旨在保留牙齿结构以维持根管治疗后牙齿的结构完整性。本研究的目的是使用数字云纹干涉测量法，评估开髓洞形设计和髓室去顶程度对不同功能负荷水平下微应变分布模式的影响。
纳入12颗拔除的人牙（n = 12），包括下颌前磨牙（n = 6）和下颌第一磨牙（n = 6）。每组标本承受10至50 N的生理压缩负荷水平。对每个标本在牙髓腔预备前（对照组（CG））、保守牙髓腔预备后（CEC）和传统牙髓腔预备后（TEC）分别采集三次数字云纹干涉测量条纹图案。采集到的条纹图案用于确定冠部和颈部牙本质的微应变分布。使用单因素方差分析和t检验对数据进行定性和定量分析（P < 0.05）。
与CEC和TEC相比，CG组完整牙冠的微应变明显更小，CEC组和TEC组的冠部微应变均有明显变化。CG组、CEC组和TEC组的冠部和颈部微应变之间均存在显著差异。
髓室顶对后牙的生物力学反应有显著影响。CEC组和TEC组在髓室去顶后，冠部和颈部水平的微应变均显著增加，与CEC组相比，TEC组导致更高的冠部微应变。
