Material jetting-based fabrication of a modified zirconia implant-supported crown: evaluation of dimensional accuracy in vitro

The dimensional accuracy and fit of zirconia implant-supported crowns fabricated using material jetting (MJ) technology remain unclear, particularly at critical intaglio interfaces. This study compared the accuracy of a modified implant-supported crown fabricated by MJ and subtractive manufacturing (SM). A modified implant-supported crown structure was designed and fabricated using MJ (Carmel 1400 C, Xjet) and SM techniques (n = 12 crowns and 12 inlays per group). Three intaglio regions were analyzed: the inlay intaglio surface (IIS), crown–inlay contact surface (CIS), and crown–abutment contact surface (CAS). Specimens were scanned, aligned to CAD references via best-fit in 3D inspection software, and assessed for trueness and precision. Trueness was analyzed using independent t-tests (α = 0.05), and intraclass correlation coefficient (ICC) was used to assess the agreement of precision. MJ exhibited significantly higher trueness than SM in all regions (p < 0.05), with the largest difference observed in the CIS region. All MJ samples remained within the clinical threshold (< 120 μm), while SM exceeded it in CIS (203.08 μm). ICC analysis showed low agreement in precision between MJ and SM. SM restorations exhibited seating interference, whereas MJ restorations achieved complete seating with good adaptation. MJ technology achieved high dimensional accuracy in implant-supported crowns with complex structures, outperforming SM in critical regions. Besides RMS values, maximum deviations in key contact areas are also clinically important, as excessive peaks may cause seating interference.