Department of Endodontics, Faculty of Dentistry, Selcuk University, Konya, Turkey.
Department of Prosthodontics, Faculty of Dentistry, Selcuk University, Konya, Turkey.
J Endod. 2018 Mar;44(3):475-479. doi: 10.1016/j.joen.2017.08.037. Epub 2017 Dec 16.
Immature teeth (IT) can be managed by using several treatment options, depending on the vitality of the tooth. The aim of this finite element stress analysis study was to evaluate the effect of different treatment procedures on the stresses in three-dimensional IT models.
Three-dimensional finite element stress analysis premolar tooth model was created as control (model 1), modified to simulate IT. Eleven models were created to simulate IT filled with (model 2) calcium hydroxide (CH), (model 3) mineral trioxide aggregate (MTA), (model 4) Biodentine (B), (models 5 and 6) MTA plug and B plug without root-filling, (models 7 and 8) MTA plug and B plug with root-filling with composite restoration, and amputation by using (model 9) CH, (model 10) MTA, and (model 11) B. Materials and structures were assumed to be homogenous and isotropic. A 300 N load was applied to the models from the functional cusps and central fossa with a 135° angle. Cosmosworks structural analysis program was used. The results were presented considering the von Mises criteria, and the scale range was limited to 0-10 + MPa.
CH use in comparison with temporary filling increased the stresses within the root. MTA filling showed less stresses when compared with B filling. MTA and B plug increased the stresses at apical and root; however, when the roots were filled using gutta-percha and the crowns were restored with composite resin, the stresses at the coronal side of the roots were reduced. The stresses were distributed more favorably in the models simulating CH, MTA, or B amputation. Amputation by using MTA and B showed similar stresses with natural tooth model.
CH is not a favorable dressing material for IT when compared with MTA and B. MTA or B plug increases the stresses at apical, whereas root-filling reduces the stresses within the root. Amputation by using CH, MTA, and B in combination with composite resin restoration may save both the coronal and root structure of IT.
根据牙齿活力,可采用多种治疗方案来处理年轻恒牙(IT)。本有限元应力分析研究旨在评估不同治疗方案对三维 IT 模型中牙齿的影响。
建立作为对照的三维有限元前磨牙模型(模型 1),并修改为模拟 IT。创建了 11 个模型,以模拟 IT 分别用氢氧化钙(CH)(模型 2)、三氧化矿物聚合体(MTA)(模型 3)、Biodentine(B)(模型 4)填充,MTA 栓和 B 栓不进行根管填充(模型 5 和 6)、MTA 栓和 B 栓进行根管填充并用复合修复体修复,用 CH(模型 9)、MTA(模型 10)和 B(模型 11)截断。假设材料和结构为同质和各向同性。从功能尖和中央窝以 135°角向模型施加 300 N 的负载。使用 Cosmosworks 结构分析程序。结果考虑了 von Mises 标准,且标度范围限于 0-10+MPa。
与临时填充相比,CH 的使用增加了牙根内的应力。与 B 相比,MTA 填充时的应力更小。MTA 和 B 栓增加了根尖和根的应力;然而,当用牙胶尖填充根管并用复合树脂修复牙冠时,根部冠侧的应力降低。模拟 CH、MTA 或 B 截断的模型中,应力分布更有利。用 MTA 和 B 截断与天然牙模型显示出相似的应力。
与 MTA 和 B 相比,CH 不是处理 IT 的理想敷料材料。MTA 或 B 栓增加根尖的应力,而根管填充则降低牙根内的应力。用 CH、MTA 和 B 联合复合树脂修复进行截断可能会保存 IT 的冠部和根部结构。