Abstract:

Objective

To investigate the influence of the fiber post on stress distribution of endodontically-treated molars restored by resin-based composite.

Methods

The CT images of maxillary 1st molar of the right side were elaborated by software， and two three-dimensional finite element models of the endodontically-treated molar， restored by resin-based composite with or without a fiber post， were developed. Static loads （600 N）， simulating the maximum bite force， were applied vertically to the occlusal surfaces of the samples， while 200 N， imitating masticatory force， were applied to functional inclinations at a 45° angle. Von Mises stresses on both the tooth and the composite restoration were calculated.

Results

With the same load static loads applied， group A and group B had similar Von Mises stress distribution. There was always a stress concentration area on the neck of the buccal side of the tooth in group B， around the cementoenamel junction. Under the maximum bite force， the peak of Von Mises stress of group B was lower than that of group A on the outer surface of residual tooth tissue，but higher on the inner surface. Under the masticatory force， Von Mises stress value of group B was below that of group A. In both cases， stress was reduced on the composite restorations of group B.

Conclusions

Insertion of the fiber post could reduce stresses on both the residual tooth and the composite restoration， thus it might have some positive effect on preventing root fracture and restoration failure. Stress concentration around tooth neck indicates a higher position of tooth fracture.

Key words: Fiber post, Resin-based composite, Finite element analysis, Stress analysis