Finite element analysis and fracture resistance testing of a new intraradicular post

Objectives

The objective of the present study was to evaluate a prefabricated intraradicularthreaded pure titanium post, designed and developed at the São José dos CamposSchool of Dentistry - UNESP, Brazil. This new post was designed to minimizestresses observed with prefabricated post systems and to improve cost-benefits.

Material and methods

Fracture resistance testing of the post/core/root complex, fracture analysis bymicroscopy and stress analysis by the finite element method were used for postevaluation. The following four prefabricated metal post systems were analyzed:group 1, experimental post; group 2, modification of the experimental post; group3, Flexi Post, and group 4, Para Post. For the analysis of fracture resistance, 40bovine teeth were randomly assigned to the four groups (n=10) and used for thefabrication of test specimens simulating the situation in the mouth. The testspecimens were subjected to compressive strength testing until fracture in an EMICuniversal testing machine. After fracture of the test specimens, their roots weresectioned and analyzed by microscopy. For the finite element method, specimens ofthe fracture resistance test were simulated by computer modeling to determine thestress distribution pattern in the post systems studied.

Results

The fracture test presented the following averages and standard deviation: G1(45.63±8.77), G2 (49.98±7.08), G3 (43.84±5.52), G4 (47.61±7.23). Stress washomogenously distributed along the body of the intraradicular post in group 1,whereas high stress concentrations in certain regions were observed in the othergroups. These stress concentrations in the body of the post induced the samestress concentration in root dentin.

Conclusions

The experimental post (original and modified versions) presented similar fractureresistance and better results in the stress analysis when compared with thecommercial post systems tested (08/2008-PA/CEP).