Retention of Overdenture Posts Cemented with Self-Adhesive Resin Cements

Purpose: This study investigated effect of 2 self-adhesive resin cements on retention of overdenture anchor posts after 30 days aging in water. Methods: Forty caries-free human cuspids were randomly assigned to 4 test groups (n = 10) according to Cement. All teeth were severed perpendicular to their long axes 2 mm coronal to CEJ. Root canals were enlarged to receive endodontic obturation and post channels were drilled 9 mm to receive Uni-Anchor Straight Type overdenture posts 1.2 mm diameter (Attachments International Inc). Posts were cemented to specimens in group A with Breeze (Pentron), self-adhesive resin cement, in group B with Max-Cem (Kerr), self-adhesive resin cement, in group C with Fuji (GC), Glass Ionomer cement and group D with Flecks (Mizzy Inc), Zinc phosphate cement (control). Roots were notched with diamond bur to ensure adequate retention to acrylic bases. Specimens were centrally positioned into plastic moulds and tray resin was poured into the moulds. Specimens were then stored in distilled water at 37 0C for thirty days. Each specimen was then placed in a special jig and loaded in tension in Instron universal testing machine (model 4301) at crosshead speed of 1mm/minute until failure. Maximum force required to dislodge each post was recorded. Means and standard deviations were calculated and data were analyzed statistically with ANOVA at (p<.05). Results: Means and SDs in N were: 706.54(204.6) for Breeze, 585.1(213.5) for Max-cem, 449.2(181.1) for Fuji & 330.4(120.6) for Fleck's. ANOVA revealed significant differences among the means (P<0003). Adhesive failure was observed with all groups except for Breeze cement where 8 specimens underwent cohesive fracture of the dentin. Conclusions: It is concluded that Breeze Cement resulted in highest retention force and most frequent cohesive failure and thus would be expected to perform clinically in superior manner. Acknowledgments: Pentron, Attachments International Inc.