Comparison of Retention of Titanium ParaPost Luted with MTA and Four Common Dental Cements: An in Vitro Study

Statement of the problem: When root perforation occurs in the middle third of the root, considerable canal length that would normally be available for post placement must be filled by the repair material, which necessitates placement of a considerably shorter post, leading to poor retention.Purpose: The aim of this study was to compare retention of titanium ParaPost luted with MTA and four different cements.Materials and methods: One hundred recently extracted human sound mandibular premolars were selected and coronal portion of each tooth was removed. The roots were endodontically instrumented and assigned to 5 groups (n=20). In five groups, the specimens were obturated with gutta-percha/AH26 sealer and the post was cemented into the roots with one of the five luting agents: zinc phosphate Harvard (group ZP), glass-ionomer GC (group GI), resin cement Panavia F2.0 (group PF2), self-adhesive cement RelyX Unicem (group RU) and mineral trioxide aggregate White ProRoot (group MTA). In each specimen, a parallel-sided titanium ParaPost was seated to a depth of 10 mm in the post space prepared with the corresponding drill size. The debonding force (Newton) was measured using a universal testing machine and the failure mode was evaluated by a stereomicroscope. Statistical analysis was performed by ANOVA and Tukey test (α=0.05). Results: The means and standard deviations of post retention in different groups were: ZP (311.3±41.0), GI (289.2±35.5), PF2 (285.0±29.5), RU (191.3±21.8) and MTA (185.0±24.4). One-way ANOVA showed significant differences in retention values between the groups (P=0.000). Tukey test showed that although there were no significant differences in the retention of posts luted with ZP, GI and PF2, they were significantly (P 0.05) higher than those luted with MTA and RU.Conclusion: The results of this study showed that retention of posts luted with mineral trioxide aggregate was lower in comparison with other common luting agents