Objectives: The objective of this study was to compare the fracture resistance and mode of failure of endodontically treated teeth restored with three different post systems at two lengths. Methods: Seventy human single-rooted premolars were endodontically treated and sectioned at the buccal CEJ. Teeth were randomly distributed into groups of ten and assigned to one of seven treatment groups. Three different pre-fabricated posts, Parapost XP, Light Post and Snowlight, were cemented at either 5 or 10 mm into a post space and standardized composite cores fabricated. A composite core group with no post served as a control. Samples were stored for 24 hours in 100% humidity at 37°C and were subsequently loaded at 90° to the longitudinal axis until ultimate failure occurred. An initial failure load and mode of failure were also recorded and analyzed using two-way ANOVA. Results: The average initial failure loads at 10 mm in Newtons were: Parapost XP 170.05 ± 60.08; Lightpost 123.29 ± 46.64; Snowlight 70.43 ± 32.26. The average initial failure loads at 5 mm were: Parapost 111.08 ± 49.84; Lightpost 64.25 ± 33.83; Snowlight 62.85 ± 18.47. The control group value was 40.24 ± 9.52. Core debonding from the tooth interface was the mode of initial failure for all samples. Root fractures upon ultimate failure occurred in 25% of the Parapost XP samples and no root fractures occurred in any other group. Conclusions: Parapost XP samples had significantly higher initial and ultimate failure loads than Lightpost or Snowlight samples at each of the two respective post lengths. Results indicate that stainless steel post provides better support for a core than glass or quartz fiber-reinforced post when a 90° load is applied. The glass and quartz fiber-reinforced post were not found to be significantly different for providing fracture resistance at 90° load angle.

Back to the Prosthodontics Research Program
Back to the IADR/AADR/CADR 82nd General Session (March 10-13, 2004)

Top Level Search