IADR Abstract Archives
Retention Force Evaluation for All-Zirconia, All-PEEK and Zirconia-PEEK Telescopic Attachments
Objectives: To investigate retention force of different CAD/CAM telescopic attachments (All-Zirconia, All-PEEK, Zirconia-PEEK telescopic attachments) for implant-retained mandibular overdenture.
Methods: Fifteen acrylic resin models of edentulous mandible without alveolar undercuts were fabricated and divided into three groups; group ZZ (primary and secondary CAD/CAM crowns were fabricated from zirconia), group PP (primary and secondary CAD/CAM PEEK crowns) and group ZP (primary crowns were fabricated from zirconia and secondary crowns from PEEK). Two implants were inserted in the canine regions and overdentures were constructed for each model. Each overdenture was subjected to 540 cycles of insertion and removal in the presence of artificial saliva, representing 6 months of usage and the extractor device of the universal testing machine was operated with crosshead speed 50 mm/min with a load cell of 3.5KN.The achieved maximum values of the retention load were recorded at the beginning of the study (initial retention) and after 540 cycles of insertion and removal simulating the clinical service(final retention). Results were statistically analyzed, ANOVA (P<0.05).
Results: (ZP) group reported the highest retention force values among all groups. Paired sample testing showed significant decrease in final retention values for the PP and ZP groups by time (p=0.001), (p=0.001) and no significant loss in retention force values for the ZZ group (p= 0.067). Statical analysis revealed significant difference between the initial and final retention of the three groups.
Conclusions: Within this study, zirconia is more preferred as a secondary telescopic crown against a primary zirconia one. Regarding the initial and final retention force values, PEEK can still be used as a secondary crown for telescopic attachment against either zirconia or PEEK primary crowns despite of the loss of retention by time.
Methods: Fifteen acrylic resin models of edentulous mandible without alveolar undercuts were fabricated and divided into three groups; group ZZ (primary and secondary CAD/CAM crowns were fabricated from zirconia), group PP (primary and secondary CAD/CAM PEEK crowns) and group ZP (primary crowns were fabricated from zirconia and secondary crowns from PEEK). Two implants were inserted in the canine regions and overdentures were constructed for each model. Each overdenture was subjected to 540 cycles of insertion and removal in the presence of artificial saliva, representing 6 months of usage and the extractor device of the universal testing machine was operated with crosshead speed 50 mm/min with a load cell of 3.5KN.The achieved maximum values of the retention load were recorded at the beginning of the study (initial retention) and after 540 cycles of insertion and removal simulating the clinical service(final retention). Results were statistically analyzed, ANOVA (P<0.05).
Results: (ZP) group reported the highest retention force values among all groups. Paired sample testing showed significant decrease in final retention values for the PP and ZP groups by time (p=0.001), (p=0.001) and no significant loss in retention force values for the ZZ group (p= 0.067). Statical analysis revealed significant difference between the initial and final retention of the three groups.
Conclusions: Within this study, zirconia is more preferred as a secondary telescopic crown against a primary zirconia one. Regarding the initial and final retention force values, PEEK can still be used as a secondary crown for telescopic attachment against either zirconia or PEEK primary crowns despite of the loss of retention by time.
