Amid Reza, Kadkhodazadeh Mahdi, Dehnavi Farshad, Brokhim Mahyar
Dental Research Center, Research Institute of Dental Sciences, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
J Adv Periodontol Implant Dent. 2018 Jun 20;10(1):35-41. doi: 10.15171/japid.2018.007. eCollection 2018.
Splinting of teeth is performed for effective distribution of loads in mobile teeth and to lower the stress applied to compromised teeth. Biomechanics cannot adequately explain load distribution around natural teeth. This study aimed to compare the distribution pattern and magnitude of stress and strain around splinted and non-splinted teeth with compromised periodontium using three-dimensional (3D) finite element analysis (FEA).
Six mandibular anterior teeth were scanned and data were registered in CATIA® and then SolidWorks® software programs. The jawbone was also designed. In the second model, the teeth were splinted with fiber-reinforced composite (FRC). The models were then transferred to ANSYS® software program and after meshing and fixing, 100- and 200-N loads were applied at zero and 30° angles. The magnitude and distribution of stress and strain in the periodontal ligament (PDL) and the surrounding cortical bone were determined.
A significant reduction in stress was noted in cortical bone around central and lateral incisors while an increase in stress was noted around the canine tooth after splinting. All these changes were more significant under 100-N load compared to 200-N load and greater differences were noted in response to the application of oblique loads compared to vertical loads.
Splinting decreased the magnitude of stress and strain in teeth close to the center of splint and increased the stress and strain in teeth far from the center of splint. Adequate bone support of canine teeth must be ensured prior to selection of splinting as the treatment plan for the anterior mandible since it increases the longevity of all the teeth.
牙齿夹板固定术用于在活动牙齿中有效分散负荷，并降低施加于受损牙齿的应力。生物力学无法充分解释天然牙周围的负荷分布情况。本研究旨在使用三维（3D）有限元分析（FEA）比较牙周膜受损的夹板固定牙和未夹板固定牙周围应力和应变的分布模式及大小。
扫描六颗下颌前牙，并将数据记录到CATIA®软件中，然后导入SolidWorks®软件程序。同时设计颌骨。在第二个模型中，用纤维增强复合材料（FRC）对牙齿进行夹板固定。然后将模型转移到ANSYS®软件程序中，进行网格划分和固定后，以0°和30°角施加100 N和200 N的负荷。测定牙周膜（PDL）和周围皮质骨中应力和应变的大小及分布。
夹板固定后，中切牙和侧切牙周围皮质骨的应力显著降低，而尖牙周围的应力增加。与200 N负荷相比，在100 N负荷下所有这些变化更显著，并且与垂直负荷相比，斜向负荷作用下的差异更大。
夹板固定可降低靠近夹板中心牙齿的应力和应变大小，并增加远离夹板中心牙齿的应力和应变。由于夹板固定会增加所有牙齿的使用寿命，因此在选择夹板固定作为下颌前部治疗方案之前，必须确保尖牙有足够的骨支持。
