Fracture Resistance, Failure Mode and Pull-Out Bond Strength of Polymer-Infiltrated Ceramic-Network Post-Core Fabricated using Computer-Aided Design/Computer-Aided Manufacturing

This study compared fracture resistance (FR), failure mode (FM), and pull-out retention in endodontically-treated teeth restored with computer-aided design- and-manufacturing polymer-infiltrated ceramic networks (PICN) to cast post-core. A total of 45 maxillary central incisors were selected, endodontically treated, and were prepared to receive the post- core restorations. The specimens were randomly divided into five groups (n = 9): CG: control (without post-core); NC1, NC2: cast nickel- chromium (Ni-Cr) post-core; and VE1, VE2: PICN post-core. Groups CG, NC1, and VE1 were subjected to the FR test, while Groups NC2 and VE2 were subjected to the pull-out retention test. FR were recorded, and FM were classified as favourable or non-favourable, while the degree of retention in the maximum force was recorded in Newton. A one-way ANOVA was used to assess the FR, and an independent T-test was used for retention of post-core. No significant mean differences of FR between Ni-Cr versus PICN group (p = 0.261). Non-favourable FM was recorded in all samples in the NC group, with 88.9% of the VE group showed favourable FM. No significant mean differences were recorded in retention between NC2 and VE2 (p>0.05). PICN post-core exhibited favourable FR, FM, and retention values, thus having the potential to be used as a substitute post-core in endodontically-treated anterior teeth.