OBJECTIVETo investigate stress distribution of different material restored post-cores in dentine and provide a theoretical guidance for clinical use.

METHODSA three-dimensional finite element model of maxillary central incisor restored with post-core and PFM crown was constructed by SCT scan technology. Based on this model, stress distribution in dentine was analyzed before and after post-core restorations with 6 different materials, including cast Ni-Cr alloy, cast titanium alloy, cast gold alloy, glass fiber reinforced composite, polythene fiber reinforced composite, and common composite resin.

RESULTSWhen the tooth was restored with cast Ni-Cr alloy post and PFM crown, the maximum tensile stress and Von Mises stress in dentin at post apex increased 152% and 162% respectively, compared with a tooth restored only with PFM crown. If polythene fiber reinforced composite was used as post material, the stress distribution did not significantly change. When the other materials were used for the post, the stress distribution changed greatly. The elastic modulus of post-core materials affected the stress distribution pattern in dentine.

CONCLUSIONThe materials with elastic modulus similar to that of dentin, such as polythene fiber reinforced composite, may be suitable for post restoration.