Accuracy of Different Complete-Arch Digital Scanning Techniques with a Combined Healing Abutment-Scan Body System

Investigate the effects of three different complete-arch digital implant scanning techniques used with a combined healing abutment-scan body (CHA-SB) system on the accuracy (trueness and precision) and scan time.

A poly(methyl methacrylate) master model simulating an edentulous maxilla was fabricated with four parallelly inserted dental implants. A CHA-SB system was attached to each implant. The model surface was scanned using a structured blue light industrial extraoral scanner to achieve a reference model standard tessellation language file (MRM-STL). Three different scanning techniques-(1) conventional technique with unmodified master model, (2) scan body splinting technique using orthodontic elastic ligatures and plastic splint materials, and (3) land-marking technique using pyramid-shaped glass-ceramic markers-were performed. Fourteen consecutive digital scans were made by using an intraoral scanner (IOS) for each technique, converted to an STL file, and superimposed on the MRM-STL. Trueness and precision were calculated for each technique. The scan time was also recorded. The data were analyzed with one-way analysis of variance (ANOVA) and Tukey honest significant difference (HSD) tests (α = .05).

Effects of different scanning techniques on the trueness (distance and angular deviations; P < .001) and scan time (P = .002) were statistically significant. For precision, different scanning techniques had only a significant effect on the distance deviation (P < .001).

Regarding trueness and precision, none of the scanning techniques was superior to others. The scan body splinting technique led to significantly less scan time.