Retention of three endodontic post systems

To evaluate the retention of three post systems using one adhesive and one cement. The hypothesis tested was that there was no significant difference among the posts.

90 freshly extracted single rooted lower bicuspids were evaluated for similar root morphology. The teeth were decoronated using an Isomet saw leaving a 15 mm-long sample. Preoperative digital radiographs were taken of all samples from the buccal and mesial direction. A glide path was established with #15K type file. Roots were then instrumented to working length to a size #40 .04 using Profile nickel titanium files. 1cc of distilled water was used as an irrigant after each file to remove dentinal debris. The teeth were then obturated with custom fit #40 0.04 taper gutta percha points and AH Plus as a sealer, using a warm vertical compaction technique. Residual gutta percha of 5 mm was left. The samples were divided into three experimental groups to receive posts. Group 1: Fiber White Para-Post No. 2 red; Group 2: No. 1 DT Light Post; Group 3: PeerlessPost No. 3. Post spaces were created in Groups 1 and 2 with the appropriate drills supplied by the manufacturer using a slow speed handpiece. The post spaces from Group 3 required no further preparation after endodontic treatment. All posts were cemented with Nexus 2 Universal Luting System. A layer of excess cement was left in the most coronal portion of the tooth for visual confirmation of tensile strength failure. Using an Instron the teeth were mounted in a custom-made jig to prevent crushing of the post and to ensure extension perpendicular to the long axis of the post. Samples were then subjected to tensile stresses until failure occurred. Failure was defined as the maximum load produced under tensile load that corresponded to visual separation of the post from the tooth. The maximum load at failure in kilograms was recorded. The average of each group was compared for significant difference. Data was analyzed using ANOVA at a significance level of P= 0.016 (Bonferroni correction for multiple t-tests).

Maximum load at failure, measured in kilograms, were as follows: PeerlessPosts 126.07 kg, Fiber White Posts 90.14kg, and DT Light Posts 88.46 kg. ANOVA revealed a statistically significant difference among the three posts systems. PeerlessPosts required statistically significantly higher force to be removed while there was no statistically significant difference between the Fiber White Posts and the DT Light Posts; therefore, the hypothesis was rejected.