Marginal bone level of dental implants using computer-aided design/computer-aided manufacturing customized abutment and prefabricated abutment–A five-year follow-up

Background/purpose: Computer-aided design/computer-aided manufacturing (CAD/CAM) allows for the customization of implant abutments as an alternative to prefabricated options. The purpose of this study was to compare the marginal bone levels of dental implants using CAD/CAM customized abutments (CA) versus prefabricated abutments (PA) over a five-year follow-up period. Materials and methods: Implants were divided into two groups based on abutment type: CA and PA. Marginal bone level (MBL), changes in MBL and bone-to-implant contact ratio (BIC), were assessed from baseline to 5 years post-prosthetics loading. Additionally, the study analyzed based on dental arches, opposing structure types, and the distance from implant platform to the cementoenamel junction of adjacent teeth (CEJ-PL). Results: Overall, MBL increased significantly for all implants from baseline to 5 years. The CA group in the mandible showed significantly higher MBL compared to the PA group (0.98 ± 0.71 mm vs. 0.54 ± 0.55 mm). Implants opposed by fixed restorations (FRs) experienced significantly more MBL compared to those opposed by natural teeth (NT) after 5 years. Implants placed at a depth greater than 3 mm (CEJ-PL > 3 mm) exhibited significantly greater changes in MBL on the distal side after 5 years compared to those placed at a shallower depth (CEJ-PL ≤ 3 mm). Conclusion: The MBL and changes in MBL showed similar trend between the CA and PA groups in the five-year follow-up. The CA group exhibited significantly more bone remodeling after one year, particularly for implants opposing FRs and those with a CEJ-PL distance exceeding 3 mm.