Effect of Loading Direction, Crown Coverage, and Adjacent Teeth on Stresses in Post-Restored Premolars

The aims of this finite elemental stress analysis (FEA) study were to evaluate the effects of loading direction, crown coverage, and adjacent teeth on stress distribution in premolar tooth models restored using fiber-post restoration. Three 3D premolar tooth FEA models were created as follows: Model 1: sound tooth; Model 2: tooth-model including root filling, fiber-post and composite resin restoration; Model 3: tooth-model including root filling, fiber-post, composite resin core and ceramic crown. Three more models were created using Models 1, 2, and 3 with adjacent teeth (Models 4, 5, and 6). The Cosmoworks structural-analysis program was used for the stress analysis, which was based on the von Mises criterion. High stress concentrations were observed at the mesial side of the sound tooth models while the stresses were localized at both sides in the others. Loading with a nonzero inclination angle caused higher stress concentrations within the tooth structure than is other models with the normal/vertical loading. The presence of adjacent teeth strongly influenced stress distributions and concentrations in Models 4, 5, and 6, reducing the stress level. Meanwhile, crown restoration did not change the stress patterns.