Stress analysis during root canal filling by vertical and lateral condensation procedures: a three-dimensional finite element model of a maxillary canine tooth

Objective To investigate the distribution of stresses that occur in a maxillary canine tooth during vertical and lateral condensation of gutta-percha in the root canal. Design An elaborate three-dimensional finite element model of a maxillary canine tooth was developed for the purposes of stress analysis. A sample stress analysis was also performed to demonstrate the variations in stress values that occur between different solutions of the same problem. Methods A 3D finite element analysis was performed, on a maxillary canine tooth model which was created using the dimensions of computer tomographic scans of a cadaveric maxilla as reference. Result If the manual operations of the endodontist are transcribed to the software by considering the finite size of the plugger or the spreader, then the maximum stresses generated in the dentine are much smaller than the reported tensile strength of this material. Conclusion The causes of the fractures in the dentine reported by previous investigators must be traced to conditions which were not considered in this study. These include aspects of modelling, which is the most important single parameter on which the final results depend. Stresses calculated by means of the complicated 3D model appear to agree with those recovered from a simpler 2D idealisation.