Complete arch implant scans with standard scan bodies versus scannable healing abutments on scanning accuracy, scanning time, and number of photograms: A comparative clinical study

Abstract

Statement of problem

Digital scans for complete arch implant fixed dental prostheses are typically performed using implant scan bodies (ISBs). Scannable healing abutments may be an alternative to ISBs. However, evidence on the accuracy, scanning time, and number of photograms of digital scans using scannable healing abutments remains uncertain.

Purpose

The purpose of this clinical study was to evaluate the scanning accuracy, scanning time, and number of photograms of scannable healing abutments of several heights in comparison with standard ISBs.

Material and methods

A reference stone cast was obtained from a patient with 7 maxillary implants from a splinted open-tray conventional impression. It was digitized by using a laboratory scanner (E4 Scanner). A milled titanium bar was manufactured, and passive fit was evaluated clinically and radiographically. Three groups (n=15) were determined based on the devices used during the intraoral scanning procedure (TRIOS 4): standard ISB (Scanbody 2800) (Group STD), 5-mm height scannable healing abutment (TissueShaper 5 mm) (Group TS5), and 7-mm height scannable healing abutment (TissueShaper 7 mm) (Group TS7). The implant abutment discrepancy between the platform of the abutments of the digitized reference cast and the intraoral scans from the different groups were calculated. Maximum deviation (highest value of misfit per scan) and overall deviations (mean of all the deviations of the scan) were considered. The scanning time and number of photograms were registered. The 1-way ANOVA and Tukey tests were used to analyze trueness. The Levene test was used to analyze the precision. ANOVA and the post hoc Tukey test were used to evaluate the scanning time and numbers of photograms (α=.05).

Results

Significant trueness differences were found in the overall and maximum misfit among the groups (P<.05). Significant precision discrepancies were revealed in the maximum misfit (P<.05) but not in the overall misfit (P=.56). The highest deviations were in the STD group (overall: 94 ±6 µm; maximum misfit: 172 ±24 µm), followed by TS5 (overall: 72 ±10 µm; maximum misfit: 112 ±15 µm) and TS7 (overall: 63 ±9 µm; maximum misfit: 91 ±20 µm). Significant differences in scanning time and number of photograms were found between the STD group and both the TS5 and TS7 groups (P<.01). The longest scanning time (129.9 ±16.7 s) and highest number of photograms (1322 ±150 photograms) were in the STD group in comparison with TS5 (71.7 ±10.8 s; 805 ±104 photograms) and TS7 (77.3 ±0.9 s; 764 ±119 photograms).

Conclusions

The tested scannable healing abutments improved the accuracy and decreased the scanning time and number of photograms in complete arch implant digital scans recorded by using the IOS assessed.