The Effect of Resection Angle on Stress Distribution after Root-End Surgery

Area of Science:

• Biomaterials Science
• Dental Mechanics
• Endodontics

Background:

• Retrograde endodontic treatment is crucial for preserving teeth.
• Understanding stress distribution in treated teeth is vital for clinical success.
• Oblique load application presents unique biomechanical challenges.

Purpose of the Study:

• To evaluate how different resection angles in apicectomy affect stress distribution.
• To analyze stress patterns in endodontically treated maxillary incisors under oblique loads.
• To compare the biomechanical outcomes of 45° and 90° apicectomy versus no apicectomy.

Main Methods:

• A 3D numerical model of an endodontically treated maxillary incisor with a fiber post was created.
• Three groups were defined: control (no retrograde obturation), 45° resection (R45), and 90° resection (R90).
• Finite element analysis was used to simulate a 45° oblique occlusal load and analyze maximum principal stress (MPS).

Main Results:

• The control group exhibited higher stress values in the surrounding bone tissue.
• Apicectomy groups (R45 and R90) demonstrated improved stress distribution in the fiber post, cement, and root dentin.
• Both apicectomy angles resulted in better stress distribution compared to the control.

Conclusions:

• A 90° apicectomy angle leads to more homogeneous stress distribution, potentially reducing failure.
• A 45° apicectomy also offers superior stress distribution over no apicectomy and is clinically feasible.
• Apical root resection angles significantly influence the biomechanical stability of retrograde endodontic treated teeth.