Marginal and Internal Fit of Monolithic Zirconia Crowns Fabricated by Using Two Different CAD-CAM Workflows: An In Vitro Study

Objectives: Few studies have evaluated the marginal fit of computer-aided design—computer-aided manufacturing (CAD-CAM) monolithic zirconia crowns fabricated through completely digital workflow; however, internal these restorations is not well known. The purpose this in vitro study was to evaluate and by using workflow, including intraoral scanner (IOS) scans, compare results those a semi-digital which combined conventional impressions, poured casts, extraoral (EOS) scanning. Materials methods: A typodont right mandibular first molar prepared for complete-coverage ceramic crown scanned an IOS. impressions preparation were also made, stone casts EOS. Virtual models generated both workflows, identical virtual anatomic contour designed CAD software. Monolithic IOS (ZI; n = 10) EOS (ZE; groups. silicon replica technique used crowns. Measurements made at 13 points on buccolingual mesiodistal cross-sections per specimen with ×6.5 ×50 zoom stereo microscope. from groups statistically compared Independent Samples t-tests Mann–Whitney U test (α 0.05). Results: Mean gap values all measurement locations ZE significantly higher than ZI (p ≤ 0.002). Overall mean ranged between 29 43 µm (median: 28–42 µm) 42 75 43–77 ZE. Conclusion: Completely workflow scans provided better CAD-CAM where obtained Yet, workflows acceptable (<120 µm). Clinical Relevance: may be advantageous fabrication as favorable can less material waste potentially shortened overall treatment time impression files transferred production facility electronically. need corroborated clinical studies.