Marginal Adaptation of Monolithic Zirconia Crowns Using Different Print Scanning Techniques.

Objectives: The aim of this study was to evaluate the marginal adaptation of monolithic crowns manufactured using different scanning techniques.
Methods: A descriptive, in vitro, comparative study was performed. A total of 60 natural teeth previously disinfected were prepared and divided into three groups of 20 (A, B,C). For each group a different scanning method was applied for its manufacturing using CAD/CAM technology. For group A the working model was scanned, for group B the final silicone impression and for group C the prepared teeth were scanned using an intraoral scanner. Before sintering the teeth, these were colored and once ready glazed. The surfaces were prepared by applying ZPRIME and then cemented using a resinous cement (RELYX, 3M EPSE), these were evaluated in four points (mesial, distal, buccal, palatine) using a scanning electronic microscope for the evaluation of the marginal adaptation.
Results: According to the quality of the marginal adaptation and type of scanning method. Group A was (40.47 SD ± 6.46). Group B (33.37 SD ± 5.78) and group C (18.49 SD ± 4.41). The L value of the H statistic, for 2 degrees of freedom was 12.69 µm for mesial, 10.71 µm for distal, 18.62 µm for the buccal and 7.08 µm for the palatine (p ≤0.05).
Conclusions: The technique of the prepared teeth obtained better results , compared to the impression scanning technique. The work model obtained the highest average , leaving this group with the largest gap. Nevertheless, all groups are within the acceptable parameters.