Retention of posts luted with phosphate monomer-based composite cement in canals obturated using a eugenol sealer

To examine the effect post-obturation sequencing had on retention of endodontic posts luted with a phosphate monomer-based resin cement into canals previously obturated using a eugenol-based sealer.

64 single-rooted teeth were decoronated, and root canals were filed, cleaned, and shaped with a size 5 Gates Glidden drill and 0.12 taper rotary instrumentation. Teeth were then divided into 4 groups of 16 specimens each. Group 1 was not obturated, and served as a control. The other three groups were obturated with gutta percha and a eugenol-based sealer. Post space preparation and post cementation were completed at three different post-obturation intervals - immediate (Group 2), 1 week (Group 3), and 4 weeks (Group 4). Ten-mm deep post spaces were prepared with a size 6 Gates Glidden drill, and size 5 Paraposts were cemented with Panavia 21 OP. Following 48-hour of storage, specimens were mounted in PVC pipe with acrylic, and the posts were removed in tensile mode using a universal testing machine at 1 mm min(-1), with data recorded in kilograms.

Group 1 (controls) mean = 61.80, SD = 16.21; Group 2 (immediate) mean = 38.70, SD = 12.97; Group 3 (1 week) mean = 43.15, SD = 14.66; Group 4 (4 weeks) mean = 18.82, SD = 8.00. Using ANOVA and Bonferroni tests, Group 1 demonstrated significantly greater mean retention strength values than Groups 2 and 3 (P < 0.05), which in turn had significantly greater mean retention strength values than Group 4 (P < 0.05).