Influence of Reconstructive Technique and Ferrule Height on Stress Distribution in Endodontically Treated Molars: A 3D Finite Element Analysis Study
Asma Al-Rumaimah, Ibrahim Al-Shami, Sara Jahaf, Abdulwahab Al-kholani, Mahmoud, ALmustafa
Background: Endodontically treated teeth restored with a different type of restorative technique may
experience a fracture. Accurate information about the stress distribution of endodontically treated
lower first molars restored with different techniques is needed. This study was conducted to investigate
and analyze the influence of reconstructive technique and ferrule effect on the stress distribution of
endodontically treated molars (ETM).
Methods: six three-dimensional finite elements (FE) models of a mandibular first molar were constructed
(via MIMIC and Solid Works software). Based on the reconstructive methods used and the presence of a
ferrule, Models have been divided into model 1 with a 2mm ferrule and model 2 without a ferrule. The
models were restored with cast-made posts (A1 and A2), fiber posts (B1 and B2), and endocrown (C1
and C2). A vertical, oblique, and horizontal load of 200N was applied to each 3D model, and Von Mises
stress was analyzed using ANSYS software.
Results: all stress values were within physiological limits under all cases of load application. Areas of
maximum stress concentration were located at the loading points of the crowns for all models except the
A2 model, in which maximum stress lies on the middle of the distal root. Models C1 and C2 showed the
highest stress, followed by models A1 and A2. while, models B1 and B2 showed the lowest stress. The
ferrule group showed more satisfactory stress distribution.
Conclusions: All the reconstructive techniques can be considered adequate alternatives for restoring
ETM. Models of fiber posts showed a homogeneous stress distribution while cast post and core models
exhibited the highest stress. The endocrown models reduced stress in the root canal's inner wall in
comparison with other models. Ferrule presence was shown a positive effect.
