Work

Internal and marginal fit of digitally fabricated all-ceramic crowns with auxiliary retentive features on short clinical abutments: a micro-CT study

Year: 2025

Type: article

Abstract: Background: Short clinical crowns/abutments (SCC) pose a challenge in achieving adequate retention. Auxiliary retentive features (ARF), such as grooves, are commonly employed to enhance retention. The marginal gap (MG) and internal fit (IF) of restorations are critical factors influencing clinical success. This study aimed to evaluate the MG, IF, and cement volume of digitally fabricated (computer-aided design (CAD) and computer-aided manufacturing (CAM)) all-ceramic crowns with and without grooves on SCC using micro-computed tomography (micro-CT). Methods: Tukey tests. Results: < 0.001). Group 1 exhibited the lowest MG and IF, followed by Group 3, Group 2, and Group 4. Group 4 showed the highest average marginal discrepancy (AMD) and average wall discrepancy (AWD) ((AMD: Z1 = 197.36 ± 10.56 µm; Z7 = 226.5 ± 8.24 µm), (AWD: Z2 = 150.05 ± 10.89 µm; Z6 = 169.38 ± 10.57 µm)), followed by Group 2 > Group 3 > Group 1. The greatest discrepancy at the cuspal area was observed in Group 2, followed by Group 3 > Group 1 > Group 4. In the central fossa, the maximum discrepancy was also noted in Group 2 (CFD = 194.48 ± 13.71 µm). No significant differences were found in total cement space volume among the groups. Conclusion: CAD/CAM crowns with grooves demonstrated clinically acceptable MG and IF values, with lithium disilicate crowns showing superior performance. These findings support the use of CAD/CAM technology for SCC restorations and underscore the importance of material selection and crown design for optimal clinical outcomes.

Source: PeerJ

DOI: 10.7717/peerj.19813