An in vitro evaluation of a carbon fiber-based post and core system

Statement of problem. A self-contained post and core system, Composipost, comprising an epoxy-based carbon fiber post, a composite core material, and a low viscosity Bis-GMA bonding resin, has recently been marketed for the restoration of pulpless teeth. Purpose. This study compared the in vitro performance and the failure characteristics of the Composipost system against existing post and core combinations. Material and methods. Using extracted human teeth, three post and core test groups and one control group were then tested to failure with an obliquely applied compressive load at 130 degrees in a Hounsfield testing machine with a crosshead speed of 5 cm/minute. Results, The mean stress values at failure (MNm(-2)) with standard deviations for each group were as follows: Composipost system 8.89, SD 2.40; stainless steel post and composite core 14.18, SD 3.49; cast gold alloy post and gold alloy core 15.25, SD 4.07; and endodontically treated tooth only 24.84 SD 4.58. Conclusion. The specimens restored with the Composipost system exhibited inferior strength properties in comparison to the other post and core systems tested (p < 0.01). Teeth without post and core foundations tested significantly stronger than the other comparison groups (P < 0.01).