IADR Abstract Archives
Evaluation of Marginal Acuracy and Retention of CAD/ CAM Cemented versus Screw Retained Implant-supported Restoration
Objectives: The aim of this study is to compare the effect of different CAD/CAM veneering techniques on marginal accuracy and retention of cemented versus screw retained esthetic implant supported restorations .
Methods: For cement retained implant supported restorations(I), custom hybrid zirconia abutments connected with the implant via titanium base were computer aided designed and computer aided manufactured CAD/ CAM and milled by VHF milling machine. Customized hybrid zirconia abutments were then overlaid by CAD/CAM Full Contoured Super Translucent Multilayered zirconia crowns (A) or Solid Zirconia copings which were furtherly veneered by Hand layering (B) using porcelain specifically developed for veneering of zirconia coping or by Pressing on using ZirPress ingots (C).For screw retained implant supported restorations (II) Super Translucent Multilayered Full contoured zirconia crowns (A) and Solid Zirconia Anatomical copings (B&C) were manufactured by same zirconia materials as cement retained and same milling machine and techniques of veneering, but they were CAD/CAM to directly screwed to implant analog.
Results: Results revealed that within all tested samples, Screw retained full contoured subgroup (IIA) showed the lowest marginal gap mean value 16.45 µm, while the Cement retained press veneered subgroup (IC) showed the highest marginal gap mean value 34.95± µm.Cement retained group recorded statistically significant higher retention mean value (458.72 N) than Screw retained group (313.84 N).The highest statistically significant retention mean value was recorded by Press veneered subgroup (446.445 N), followed by Hand veneered subgroup (359.025 N), then Full contoured subgroup (353.375 N).
Conclusions: Screw retained implant supported zirconia crowns had better marginal adaptation than Cement retained.Full contoured implant supported zirconia crowns had better marginal adaptation than veneered (hand layered or pressed on). Cement retained implant supported zirconia crowns recorded higher retentive mean values than screw retained. Press veneered implant supported zirconia crowns showed higher retentive mean values than full contoured or hand veneered.
Methods: For cement retained implant supported restorations(I), custom hybrid zirconia abutments connected with the implant via titanium base were computer aided designed and computer aided manufactured CAD/ CAM and milled by VHF milling machine. Customized hybrid zirconia abutments were then overlaid by CAD/CAM Full Contoured Super Translucent Multilayered zirconia crowns (A) or Solid Zirconia copings which were furtherly veneered by Hand layering (B) using porcelain specifically developed for veneering of zirconia coping or by Pressing on using ZirPress ingots (C).For screw retained implant supported restorations (II) Super Translucent Multilayered Full contoured zirconia crowns (A) and Solid Zirconia Anatomical copings (B&C) were manufactured by same zirconia materials as cement retained and same milling machine and techniques of veneering, but they were CAD/CAM to directly screwed to implant analog.
Results: Results revealed that within all tested samples, Screw retained full contoured subgroup (IIA) showed the lowest marginal gap mean value 16.45 µm, while the Cement retained press veneered subgroup (IC) showed the highest marginal gap mean value 34.95± µm.Cement retained group recorded statistically significant higher retention mean value (458.72 N) than Screw retained group (313.84 N).The highest statistically significant retention mean value was recorded by Press veneered subgroup (446.445 N), followed by Hand veneered subgroup (359.025 N), then Full contoured subgroup (353.375 N).
Conclusions: Screw retained implant supported zirconia crowns had better marginal adaptation than Cement retained.Full contoured implant supported zirconia crowns had better marginal adaptation than veneered (hand layered or pressed on). Cement retained implant supported zirconia crowns recorded higher retentive mean values than screw retained. Press veneered implant supported zirconia crowns showed higher retentive mean values than full contoured or hand veneered.
