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Tanu Gupta
Ashish Choudhary
Prabhakar Gupta
Sachin Kumar


Double-crown-retained mandibular overdentures, PEEK frameworks, Retention, Wear


Purpose: To evaluate the change in the retention of novel metallic and non-metallic combinations for double-crown-retained mandibular overdentures on implants.

Methods: Cylindrical bases were used to insert four implants arranged in an arch, with 10 mm inter-implant spacing anteriorly, and 35 mm posteriorly. Five groups (n = 8 each) of different materials combinations were tested for retention: zirconia abutments/PEEK framework (ZP), PEEK abutments/ PEEK framework (PP), titanium abutments/PEEK framework (TP), titanium abutments/CoCr framework (TC), and titanium abutments/gold copings/cobalt-chromium framework as the control group (TG). The abutment retention height was 4 mm with 1° convergence angle.

Results: The initial median retention of all groups ranged from 10.0 to 33.3 N. After 10,000 insertion/separation cycles, the median retention ranged from 10.3 to 35.0 N. The change in the retention after 10,000 cycles was not statistically significant within groups ZP and TG. For groups PP and TP, there was a slight increase in retention with partial significance. The retention of group TC showed fluctuation with a partially significant decrease in retention.

Conclusions: The use of novel metallic and non-metallic combinations in the construction of double-crown-retained mandibular overdentures on implants resulted in acceptable levels of retention and might be recommended for clinical application.


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