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Published on: December 20, 2024
Different CAD/CAM-processing routes for zirconia restorations: influence on fitting accuracy
Philipp Kohorst1, Janet Junghanns, Marc P Dittmer
1Department of Prosthetic Dentistry and Biomedical Materials Science, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany. Kohorst.Philipp@mh-hannover.de
Computer-aided design/computer-aided manufacturing (CAD/CAM) systems offer superior fitting accuracy for four-unit zirconia fixed dental prostheses compared to CAM-only systems. All evaluated processing routes yielded clinically acceptable results, but CAD/CAM demonstrated greater precision.
Area of Science:
- Dental Materials Science
- Biomaterials Engineering
- Prosthodontics
Background:
- Computer-aided design/computer-aided manufacturing (CAD/CAM) has revolutionized dental prosthetics fabrication.
- Zirconia is a popular material for fixed dental prostheses (FDPs) due to its strength and aesthetics.
- The processing route can significantly impact the fitting accuracy of CAD/CAM-fabricated restorations.
Purpose of the Study:
- To evaluate the influence of different processing routes on the marginal fitting accuracy of four-unit zirconia FDPs.
- To compare the precision of laboratory CAD/CAM, in-laboratory CAD/CAM, and centralized milling center production methods.
Main Methods:
- Three groups of ten four-unit zirconia frameworks were fabricated using different processing routes: CerconCAM (CAM-only), CerconCAD/CAM (in-laboratory CAD/CAM), and Compartis (centralized milling).
- Frameworks were veneered with recommended ceramics.
- Marginal accuracy was assessed using a replica technique, measuring horizontal marginal discrepancy, vertical marginal discrepancy, absolute marginal discrepancy, and marginal gap. Statistical analysis was performed using one-way ANOVA (p < 0.05).
Main Results:
- Mean horizontal discrepancies ranged from 22 μm (CerconCAM) to 58 μm (Compartis).
- Mean vertical discrepancies ranged from 63 μm (CerconCAD/CAM) to 162 μm (CerconCAM).
- Mean absolute marginal discrepancies ranged from 94 μm (CerconCAD/CAM) to 181 μm (CerconCAM), with marginal gaps between 72 μm (CerconCAD/CAM) and 112 μm (CerconCAM, Compartis).
- All processing routes resulted in clinically acceptable marginal accuracy.
- Significant differences in marginal accuracy were observed based on the processing route (p < 0.05).
Conclusions:
- CAD/CAM systems demonstrated higher precision in manufacturing four-unit zirconia FDPs compared to a CAM-only system.
- The processing route significantly influences the marginal accuracy of zirconia FDPs.
- All evaluated methods produced restorations with clinically acceptable marginal fit.
