Digitization of a Single Tissue-Level Implant Without Scan Body - A Feasibility Study.

OBJECTIVE

This in vitro feasibility study evaluated the agreement between virtual implant positions obtained from intraoral scans of a tissue-level implant with and without a scan body for single-crown restorations.

METHODS

Three intraoral scanners (TRIOS 5 (TRI), Primescan (PRI), and DCS Scan (DCS)) were used to digitize one tissue-level implant placed in a typodont model with a fully visible implant shoulder. Ninety-six intraoral scans were obtained, with each scanner performing 16 scans with a scan body (SB) and 16 scans without a scan body (noSB). An additional 32 scans were acquired with a laboratory scanner for comparison. Linear deviations at the implant shoulder and apex, as well as angular deviations, were evaluated. Statistical analysis included one-way ANOVA, Scheffé's method for multiple comparisons, and unpaired t-tests (p<0.05).

RESULTS

At the implant shoulder, linear vector deviations between SB and noSB scans remained below 100 µm in all scans except one DCS scan, and no significant differences were detected among the intraoral scanners (p>0.05). Deviations were larger at the implant apex, where DCS showed significantly greater deviations between SB and noSB scans than TRI and PRI (p<0.01). Compared with the laboratory-scanner SB scans, noSB scans showed no significant differences among scanners at the implant shoulder or apex (p>0.05).

CONCLUSION

Under the restricted conditions of this in vitro study, intraoral scans of ideally positioned tissue-level implants without a scan body showed close agreement with scan-body-based scans at the implant shoulder. The workflow may be feasible for selected tissue-level implant situations in which the implant shoulder and internal geometry are fully visible and the implant-specific CAD geometry is available. However, omitting the scan body may increase deviations, particularly at the implant apex, in a scanner-dependent manner. Clinical studies and restoration-fit analyses are required before clinical recommendations can be made.

CLINICAL SIGNIFICANCE: Direct intraoral scanning of selected, ideally positioned tissue-level implants without a scan body may simplify the digital workflow for single-implant crowns. However, this approach should not yet replace established scan-body workflows until validated by clinical and restoration-fit studies.