Accuracy of scannable anatomic healing abutments for implant-supported crown and fixed partial prostheses: An in vitro comparison with conventional scan bodies.

STATEMENT OF PROBLEM Accurate digital implant scanning is critical for the fit, function, and biological stability of implant-supported restorations. Anatomic scannable healing abutments (AHAs) have been proposed as an alternative to conventional scan bodies (SBs) to simplify digital workflows and facilitate the development of an adequate emergence profile. However, their accuracy in crown and short-span fixed dental prosthesis scenarios remains insufficiently investigated.

Purpose

The purpose of this in vitro study was to compare the trueness and precision of implant position detection obtained using AHAs versus SBs in single-crown and short-span fixed dental prosthesis configurations. MATERIAL AND

Methods

Two partially edentulous maxillary models were digitally designed and 3-dimensionally (3D) printed: 1 with a single molar edentulous site and 1 with a 3-tooth posterior edentulous span. Implant analogs were placed in the models to simulate a single implant site and a 3-unit implant fixed dental prosthesis site. AHAs (test group) or SBs (control group) were connected to the analogs. A desktop scanner was used to obtain baseline scans for each group, while 15 consecutive intraoral scans per group were acquired using an intraoral scanner. Linear (mesiodistal, buccolingual, coronoapical), angular, and overall 3D deviations at the implant platform center were calculated and analyzed using the t test and Mann-Whitney U test.

Results

For the single-crown model, AHAs demonstrated significantly better mean 3D trueness than SBs (20 µm and 74 µm; P<.001), as well as better angular deviation (0.11 degrees and 0.44 degrees; P<.001). Precision was also better for AHAs, with a mean 3D deviation of 10 ±5 µm compared with 67 ±37 µm for SBs (P<.001). In the 3-unit fixed dental prosthesis model, AHAs consistently showed better trueness and precision at both premolar and molar positions. At the molar site, mean 3D trueness was 24 µm for AHAs versus 103 µm for SBs (P<.001), and mean 3D precision was 22 ±9 µm versus 79 ±54 µm (P<.001).

Conclusions

AHAs demonstrated significantly higher trueness and precision than SBs for implant position detection in single-crown and short-span fixed dental prosthesis scenarios.