Retention of Zirconia-PEEK versus cobalt-chromium-PEEK telescopic attachments for implants retained mandibular overdenture

Objective: The study compared the retention of two types of telescopic attachments made of Zirconia-PEEK and cobalt-chromium-PEEK for complete lower dentures retained by implants. Subjects and Methods: Twelve completely edentulous patients were randomly chosen. The patients were allocated into two groups; Group I, received a zirconia primary coping and PEEK as a secondary coping’s telescopic attachment. Group II (The control group) : Patients received a cobalt chromium primary coping and PEEK as a secondary coping’s telescopic attachment. A nexygen universal testing machine measured retention at three month intervals for 12 months in both groups. Results: Zirconia-PEEK double crown has recorded higher retentive value than cobalt-chromium-PEEK double crown at baseline, three months, and six months with difference not considered as statistical significances as P value > 0.05. But at 9 months Cobalt-chromium-PEEK double crown recorded higher retentive value than zirconia-PEEK double crown with differences considered as statistical significanse as P value ≤ 0.05.Conclusion: In spite of the good esthetic and lightweight advantages of zirconia, cobalt-chromium has significantly higher retentive value than zirconia.