Strain Gauge Analysis of the Stresses Induced by Different Secondary Coping Materials in Tooth Supported Telescopic Overdentures.

Purpose: To compare the stresses induced on the supporting abutments by different secondary coping materials; zirconia, Polyetheretherketone (PEEK) and Polyetherketone ketone (PEKK) in tooth supported telescopic overdentures using strain gauge analysis.

Materials and methods: A virtual model simulating a completely edentulous mandibular arch with two telescopic overdenture abutments in the canine region was designed and printed. The abutments received a milled zirconia primary coping. The secondary coping was milled out of zirconia in the model ZR, PEEK in the model PE and PEKK in the model PK. Five overdentures were made for each model. Strain gauge rosettes were bonded mesial and distal to each abutment. Unilateral and bilateral loadings were applied. An ANOVA test was used for statistical analysis between the three models.(α=0.01).

Results: Significant differences were found between the three models during unilateral and bilateral loading. Post Hoc Tukey tests showed significant difference between ZR and PE models, ZR and PK models in addition to PE and PK models during unilateral and bilateral loading.

Conclusion: Zirconia copings induced the highest stress while the lowest stress values were induced by the PEKK copings.