Influence of Different Elastic Moduli of Dowel and Core on Stress Distribution in Root

This study was carried out to investigate the influences of elastic moduli of the dowel-core combination on the stress distribution in the root by the use of 2-dimensional finite element analysis. The peak stress at the dowel-cement interface was influenced strongly by a change of elastic modulus of the post (from 20, 000kg/mm2 as a hard prefabricated post to 8, 000kg/mm2 as a custom cast post) for both vertical and 45 degree oblique loading (ρ>90%). Peak dentinal stress adjacent to the luting cement layer depended only on the post material for vertical loading (ρ≈99%). In contrast, the post and core materials (from 8, 000kg/mm2 as cast core to 300kg/mm2 as composite resin core) acted in cooperation on the stress magnitude for oblique loading, but the influence of the core material was stronger than that of the post (ρ of core≈41% and ρ of post≈26%). On the other hand, at the marginal region the effect of the core material contributed more than 86% to the peak stress value for both loadings, and the post material affected at most about 11% of the bending resistance.