Comparative Evaluation of Trueness and Precision of PMMA Three-Unit Bridges Fabricated Using Three Milling Devices

Year 2025, Volume: 3 Issue: 1, 12 - 16, 30.04.2025

Gökçen Dinçer , Münir Demirel

https://doi.org/10.62243/edr.1643661

Abstract

Aim This in vitro study aimed to evaluate the trueness and precision of three-unit bridge restorations fabricated using different milling devices.
Material and method A dental model prepared for bridge restorations in the right first premolar and first molar was scanned using a laboratory scanner (inEos X5, Dentsply Sirona). The data were imported into dental design software (DentalCAD 3.1 Rijeka; exocad GmbH) to create a bridge restoration design, saved as a reference (R-STL). Ten bridges were milled from polymethylmethacrylate blocks (Telio CAD LT A2 B55, Ivoclar Vivadent, Liechtenstein) using three milling devices: Cerec MC XL (C-STL), Cerec Primemill (P-STL), and inLab MC X5 (X-STL). The restorations were rescanned with an intraoral scanner (Cerec Primescan, Dentsply Sirona), and the datasets were analyzed using a 3D analysis program (Geomagic Control X v.2020.1, 3D Systems, NC, USA). Statistical analyses included one-way ANOVA, post hoc Tukey tests, and the Shapiro-Wilk test (α = 0.05).
Results Significant differences in trueness were observed among the groups (p < 0.001), with the inLab MC X5 device (X-STL, RMS = 32 μm) showing the highest trueness and the Cerec MC XL group (C-STL, RMS = 44 μm) the lowest. No significant differences in precision were found (p = 0.117).
Conclusion The choice of milling device significantly affects the trueness of three-unit bridge restorations, with the inLab MC X5 device producing the most accurate results. However, precision did not differ significantly among the devices.

Keywords

Milling devices, Polymethylmethacrylate, Precision, Three-unit bridge, Trueness

Ethical Statement

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Supporting Institution

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Thanks

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