Retention strength of ball-attachment titanium post for removable partial denture or overdenture

Aim: To evaluate the retention of an endodontic titanium post with a spherical head for removable partial denture or overdenture attachment according to surface treatment type. Methods: Sixty healthy single-rooted teeth, sectioned at the enamel/cementum junction, were treated endodontically and steadily fixed in the embedding acrylic resin. The titanium posts were subdivided into four groups: control, no surface treatment (Ctrl); posts with macro-retentive grooves (MR); air abrasion of the post surface (AB); and posts with macro-retentive grooves and air abrasion of the post surface (MR+AB). The posts were luted in the root canal using self-adhesive dual resin cement. Pull-out testing was performed using a universal testing machine until complete detachment was achieved. After pull-out testing, the metallic posts were examined under an optical microscope and the failures were classified based on the cement distribution pattern on the extracted posts: 0, no cement left on the post (cement/post failure); 1, post surface partially covered by adhered cement (post/cement and dentin/cement mixed failure); 2, post surface completely covered by cement (dentin/cement failure). The retention data were analyzed by one-way ANOVA, Bonferroni–Dunn test (p<0.05) and Weibull analysis. Results: AB showed the highest retention value (485.37±68.36), followed by MR+AB (355.80±118.47), MR (224.63±42.54) and Ctrl (113.12 ± 51.32). AB and MR showed the highest Weibull moduli. Conclusions: The data indicated that air abrasion alone could significantly increase the retention of titanium posts/attachments for use with overdentures or removable partial denture.