Comparitive evaluation of marginal fit of zirconia copings fabricated using two different CAD systems with one CAM system: An In-vitro study

This study directed towards the in vitro evaluation of the vertical marginal fit of zirconia copings fabricated by using two different scan and cad systems. The scan systems used were LAVATM SCAN ST SCANNER and 3SHAPE D900 SCANNER. In this study the tested copings were not cemented to the die before evaluation because when specimens are cemented, they may lose the precision of the primary adaptation, thereby allowing cement type, viscosity and cementation techniques to influence the results.The precision of the marginal fit was evaluated by direct viewing and external measurements as opposed to sectioning. In comparison with 3SHAPE AND LAVA ST, four aspects are taken. Comparing the mesial aspect 3SHAPE HAS 25.1973 microns, LAVA 35.7900, In Buccal aspect 3SHAPE has 16.8293, LAVA 32.2420, In Distal 3SHAPE has 26.4273 and LAVA has 50.1840, In lingual aspect 3SHAPE has 27.8533 and LAVA has 25.9127. 3SHAPE specimens shows marginal mean deviation of 24.0768 and LAVA shows 36.032 marginal deviation. These results indicated that the scanning system did affect the marginal fit of CAD/CAM ceramic restorations, regardless of the ceramic type.The result shows 3SHAPE D900 scanner have more accuracy than LAVATM ST SCANNER