Marginal Fit of Metal Copings Made by Three Fabrication Routes

Objective: The accuracy of marginal fit is essential for the longevity of metal restorations because any gap increases biological and mechanical risks. Digital fabrication methods, such as milling and 3D printing, were introduced to reduce the errors seen in conventional casting. This study compares the marginal gaps of copings made by the three techniques to identify the most accurate method within clinical limits. Materials and Methods: Thirty copings, ten per technique, were made on a standardized maxillary molar preparation. Vertical marginal gaps were measured at the buccal and lingual reference points under a stereo microscope at ×40 using image analysis software. Results: Mean marginal gap was 36.05 μm for printed Co-Cr, 45.15 μm for milled Ti, and 67.04 μm for cast Co-Cr. Differences were significant at p ≤ 0.05. Conclusion: 3D printing produced the smallest gaps, followed by milling, then casting. All means were within a commonly accepted clinical limit of 100 μm. Clinical significance, digital workflows can reduce inaccuracy and support restoration longevity.