磨牙牙体缺损桩核冠与全冠修复的应力对比研究

Stress comparison and analysis of post-core crown and full crown in severely defected molar

目的对比分析磨牙牙体大面积缺损桩核冠和全冠修复后,存留牙体组织的应力状况,为磨牙牙体缺损的修复设计提供参考。方法分别建立上下颌磨牙大面积缺损桩核冠修复和牙体充填后全冠修复2种修复方式的三维有限元分析模型,模拟牙齿在咀嚼过程的受力情况,计算分析上述2种修复状况下,存留牙体组织的应力分布状况。结果磨牙桩核冠修复后应力集中区在根管口和牙颈部;全冠修复后,应力集中在牙颈部,全冠修复后牙颈部的最大应力小于桩核冠修复后根管口的最大应力。结论磨牙大面积缺损修复时,若牙体预备后存留壁厚度不小于1.5mm,全冠修复较桩核冠修复更有利于利用牙齿固有结构保存存留牙体组织的抗力性。

Objective To compare and analyze the stress distribution of the remaining tissue of defected mandibular molar after post-core crown and full-crown restoration. Methods 3-D finite element analysis models for postcore crowns and full crowns restoration of severely defected mandibular molar were established. By stimulating the chewing process, stress distribution of the remaining tissue of teeth was calculated and analyzed. Results The stress of mandibular molar after post-core crown restoration concentrated upon root canal orifice and dental cervix. In full crown restoration, the stress concentrated upon dental crown and dental cervix. Conclusion When restoring severely defected teeth, full crown restoration is better than post-core crown in keeping natural structure and strength of teeth.