Effects of Abutment and Screw Access Channel Modification on Dislodgement of Cement-Retained Implant-Supported Restorations

This study investigated the influence of implant abutment and screw access channel modification on the retention of copings. Titanium abutment access openings were either left open or modified by placing two vent holes 3 mm from the occlusal edge and 180 degrees apart. Access openings sealed with a resin material were used as controls. Metal copings were cemented and subjected to tensile testing until failure. Access openings with two vent holes resulted in significantly higher mean retention values compared to the opened or sealed screw access groups (P .05). Cement flow was affected by the internal vent, which increased the area of cementabutment contact.