Effect of intraoral scanning distance on the marginal discrepancy of milled interim crowns

Abstract

AbstractPurposeTo compare the marginal discrepancy between milled interim crowns fabricated using intraoral digital scans acquired at different scanning distances.Materials and methodsTen acrylic typodont teeth were prepared for interim crowns. Three different resin frames of 2.5‐, 5‐, and 7.5‐mm heights were fabricated and attached to an intraoral scanner (Omnicam). Three groups were created based on the different scanning distances tested: 2.5 mm (Group A), 5 mm (Group B), and 7.5 mm (Group C). Intraoral digital scans were performed on four tooth surfaces: mesial, distal, buccal, and lingual (n = 10). Each experimental scan was used to design and fabricate a milled polymethylmethacrylate anatomically contoured crown. Vinyl polyether silicone was used three times to assess the marginal discrepancy of the specimens by measuring five marginal points on digital photographs. One‐way analysis of variance test was used to analyze the data, followed by Tukey's honestly significant difference test (α = 0.05).ResultsThe mean marginal discrepancy values in Group C were significantly higher than those in Groups A (p ≤ 0.000) and B (p = 0.001). There was no significant difference between Groups A and B (p = 0.702). There were no significant differences among the four surfaces in any of the scanning distance groups (p1 = 0.583, p2 = 0.390, and p3 = 0.135; p > 0.05).ConclusionsThe interim crowns fabricated with a scanning distance of 7.5 mm showed the greatest marginal discrepancy when compared with crowns fabricated using 2.5‐ and 5‐mm scanning distances.