Optical Stereometric Analysis of Milled and Not-Milled Copings for Removable Overdentures on an Experimental Partially Edentulous Mandible

ORIGINAL ARTICLE
Srđan D. Poštić, Slobodan Dodić, Ivan V. Tanasić, Miloš Milošević, Stevan Avramov, Vladimir Biočanin, Ljubiša Ristić, Igor Đorđević, Aleksa Milovanović, Miloš Maksimović, Ekatarina Ž. Džigurski, Predrag M. Šojić

 
For citation: Poštić SD, Dodić S, Tanasić IV, Milošević M, Avramov S, Biočanin V, Ristić L, Đorđević I, Milovanović A, Maksimović M, Džigurski EŽ, Šojić PM. Optical Stereometric Analysis of Milled and Not-Milled Copings for Removable Overdentures on an Experimental Partially Edentulous Mandible. International Journal of Biomedicine. 2026;16(2):232-241. doi:10.21103/Article16(2)_OA13
 
Originally published June 5, 2026

Abstract: 

Background: This study aimed to examine the effect of differential stress distributions on the occlusal surfaces of the control and experimental copings.
Methods and Results: The study used two master casts of a lower jaw with bilateral terminal edentulous seats. Their topography was identical, indicating a partially edentulous lower jaw according to Eichner's B3 (and C2) classification (i.e., Kennedy class 1). The control cast had conventional oval copings. The experimental cast had the surfaces simulating three specific milled copings covering the remaining tooth substance. Controlled loading was measured using a gnathodynamometer. Loading stages were at 400, 800, and 1000 N. Measurements of strain and displacement were provided by the Digital Image Correlation Method. The "Wilcoxon Lambda" two-sample test was used in the analysis of deformation between the control rounded and experimental milled copings under loading.
Smaller values of deformations were measured on milled copings. There were statistically significant differences in displacement between the control rounded and experimental milled copings (Pr > |Z| = 0.001) as well as in deformations (Pr > |Z| = 0.0298).
Conclusion: Experimental milled copings are less susceptible to deformation than the control rounded copings. These findings may have clinical significance for improving primary and secondary retention of overdentures on milled copings.

Keywords: 
copings • overdenture • shortened dental arch • digital image correlation technique • optic stereometry
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Received March 23, 2026.
Accepted May 7, 2026.
© 2026 The Author(s). International Journal of Biomedicine is published by IMRDC.
This is an open access article under the CC BY-NC-ND 4.0 license.