Year: 2022 | Month: June | Volume 9 | Issue 1

Evaluation of Marginal and Internal Fit Discrepancy of Crowns Fabricated Using Conventional, Milling, and Three Dimensional Printing Techniques

Urvashi Sharma M. R. Dhakshaini Shrutik Krishna Poojary K. N. Raghavendra Swamy
DOI:10.30954/IJDMS.1.2022.1

Abstract:

Aim: The aim of this study was to evaluate and compare fit of metal crown fabricated through conventional, Computer-aided design and manufacturing (CAD/CAM), and direct metal laser sintering (DMLS) (3D printing) techniques. Materials and Methods: A  lower typhodont molar tooth was prepared. The impression was made using elastomeric impression material. The impression was poured with type  IV die stone. Molar die was prepared. Ten cobalt chromium crowns were prepared using lost wax technique. Then, the die was scanned using lab scanner (UP 3D Acublu, Germany) and the image was saved as a standard tesellation language (.stl) file in a CAD software (ExoCAD Matera, Germany). Crown was virtually designed and ten crowns were milled using cobalt chromium blocks. The same.stl file was sent to DMLS printer (Object Eden 260VS; Stratasys) and 30 crowns were printed using cobalt chromium powder with a 5  µm layering thickness. Silicone replica technique was used to measure the marginal and internal fit. Horizontal marginal fit was measured at eight different points on the sample. Then, the sample was sectioned mesiodistally and internal gap was measured at five different points. All the measurements were done in ×50 magnification of a stereolitho microscope. Results: The conventional group showed the highest mean internal and marginal gap of 90.37  µm and 73.05  µm, respectively. 3D-printed crowns showed lowest mean marginal and internal gap of 27.27  µm and 23.83  µm, respectively. Conclusion: Fit discrepancy of crowns fabricated through the three techniques was within clinically acceptable range. However, 3D-printed crowns showed the best fit.

• PDF Download