# The Effect of Stress Distribution by Fiberglass Post System With Different Designs on Endodontically Treated Maxillary Central Incisors: A Three-Dimensional Finite Element Analysis

## TL;DR

This study uses 3D modeling to compare how different fiberglass post designs affect stress in treated teeth under various chewing forces.

## Contribution

The study introduces a finite element analysis comparing stress distribution in different fiber post designs for restored teeth under varied loading conditions.

## Key findings

- Tapered posts caused the highest stress in dentin and cementum under vertical loading.
- Parallel posts showed the least stress in dentin, cementum, and periodontal ligament under oblique loading.
- FEA results suggest parallel fiber posts reduce stress in tooth-restoration complexes.

## Abstract

Background: The stress distribution pattern in endodontic posts under masticatory load is crucial for optimizing prosthesis design. Limited research exists on the effect of various force vectors on teeth restored with fiber posts of different designs. This study analyzes and compares the stress distribution in endodontically treated maxillary central incisors restored with fiber posts of varying designs using finite element analysis (FEA).

Methods: Three identical 3D finite element models of a maxillary central incisor were created from computed tomography (CT) scan images. Three models with different glass fiber post designs (parallel, tapered, and two-stage cylindrical) were also developed. Stress analysis was conducted using the ANSYS 12.1 software (ANSYS, Inc., Canonsburg, PA, USA) under a physiological load of 70 N, applied at 90°, 45°, and 180° angles to the maxillary incisor restored with a post, core, and crown until the prosthetic complex fractured.

Results: Under vertical loading, the tapered post showed the highest stress concentration at the dentin and cementum levels, with values reaching 5.078 MPa and 3.227 MPa, respectively. Horizontal loading resulted in lower von Mises stress levels at the cancellous bone (4.316 MPa) and within the post (8.385 MPa) for the tapered post. The parallel post demonstrated the least stress in dentin (5.1598 MPa), cementum (10.0258 MPa), and periodontal ligament (PDL) (0.0107 MPa) under oblique loading.

Conclusions: This study suggests that post selection should be based on each clinical scenario's material properties and design considerations. FEA results showed significantly lower stress values in various regions of the tooth-restoration complex when a parallel fiber post was used in endodontically treated maxillary central incisors.