Effect of Different Treatment Options on Biomechanics of Immature Teeth: A Finite Element Stress Analysis Study

Introduction: 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. Methods: 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 degrees 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 + M Pa. Results: 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. Conclusions: 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.