Zahraa M Al-Hawwaz* and Adel F Ibraheem

Department of Conservative and Cosmetic Dentistry,
College of Dentistry, University of Baghdad, Baghdad, Iraq.


The objective of this in vitro study was to evaluate and compare the marginal and internal gaps of full contour zirconia crowns using three different digital intra-oral scanners with different software design. Samples were distributed into five groups eight for each according to the type of scanner and software design used during milling procedure as follows: Group A: CEREC Omnicom + InLab SW 16.1. Group B: TRIOS3 + software of 3Shape dental system.  Group C: TRIOS3 + InLab SW 16.1. Group D: CS3600 + software of exocad program.  Group E: CS3600 + InLab SW 16.1. The crowns of all groups were milled with the same milling machine inLab MCX5. The marginal and internal fitness of crown was evaluated by direct measurement of cement thickness through sectioning procedure. The data were then analyzed using One-way ANOVA test and Tukey’s (HSD) test. The results of this study showed that the least marginal gap was recorded in Group C (59.038, ±9.667) followed by Group D (63.405, ±6.038), Group E (64.674, ±6.478), Group B (70.112, ±4.954) and Group A (81.703, ±7.428) respectively. While for the internal gap, the least internal gap was recorded at Group C and Group B (119.691, ±4.107), (119.192, ±4.068) respectively followed by Group A (123.254, ±6.777), Group D (123.485, ±5.353) and Group E (130.816, ±3.926). As a conclusion, the intra-oral scanner that provides more accurate seating of monolithic crown restoration was TRIOS3.

Keywords: intraoral scanner, digital impression, STL datasets, CAD/CAM, all ceramic restoration, marginal fitness, internal fitness.