Characterizing the Abutment Prosthetic Support Interface of a Hybrid Abutment In Vitro for Single and Partial Fixed Dental Prostheses

PURPOSE: To investigate the resistance, retention, and prosthetic adaptability of an abutment prosthetic support interface (APSI) for single and splinted implant restorations. MATERIALS AND METHOD: Twenty-five 3 mm hexagonal-tapered hybrid abutments were subjected to fatigue testing to evaluate resistance of cemented metal crowns, applied on-axis and off-axis. Crowns of three different heights, 10 mm, 12 mm, and 14 mm were assessed. Retention was evaluated via dislodgement force testing for two configurations, single crowns (n=5) cemented on five 3 mm-high hybrid abutments and five 6 mm-high 8° tapered abutments; and splinted two-unit prostheses (n=10) cemented on two 3 mm-high hybrid abutments and two 3 mm-high 8° tapered abutments, both arranged in converging implant configurations. RESULTS: All resistance specimens subjected to axial loading survived 1 million cycles. Off-axis loading resulted in implant body fractures in all specimens for 12 mm and 14 mm crown heights. Mean number of cycles to failure was 320,117 ± 114,230 for the 12 mm group and 137,375 ± 144,420 for the 14 mm group. Mean dislodgment forces of single crowns cemented on 3 mm-high hybrid abutments compared to 6 mm-high 8° tapered abutments were significantly different (p