Marginal fit of titanium and zirconia abutments: Micro-CT analysis

The lack of high-resolution three-dimensional evidence comparing marginal fit and biological sealing between CAD/CAM titanium and zirconia abutments manufactured under identical digital workflows remains a critical gap in implant prosthodontics. Digital workflows enhance implant prosthodontic precision, yet differences in marginal fit between CAD/CAM titanium and zirconia abutments are unclear. Therefore, it is of interest to assess marginal adaptation, internal fit and bacterial microleakage of 60 digitally fabricated abutments using micro-CT and bacterial infiltration tests. Titanium abutments showed smaller marginal gaps (12.4 ± 3.8 µm) and higher internal contact (73.2 ± 8.4%) than zirconia (23.7 ± 6.2 µm; 58.9 ± 11.7%) (p < 0.001). Bacterial leakage was lower in titanium (13.3%) compared to zirconia (43.3%) (P < 0.05). Thus, CAD/CAM titanium abutments demonstrated superior marginal fit, internal adaptation and microbial sealing.