Accuracy of complete arch implant scans recorded by using intraoral and extraoral photogrammetry systems and a noncalibrated splinting technique: A clinical study.

Abstract

Statement of problem: Different implant scanning techniques can be used to capture the position of the implants being restored, including intraoral and extraoral photogrammetry (PG) systems and noncalibrated splinting methods. However, clinical studies that have analyzed the accuracy these implant scanning techniques are sparse.

Purpose: The purpose of this clinical study was to assess the trueness and precision of complete arch implant scans captured by using 2 extraoral and an intraoral PG system and a noncalibrated splinting technique.

Material and methods: A patient with a maxillary edentulous arch with 4 osseointegrated implants participated in the study. Each implant had an implant abutment (SRA RB Abutment). To obtain the reference file (control), an optical marker (iCam4D scan body) was hand tightened on each implant abutment, and 10 consecutive PG scans were obtained by using a calibrated extraoral PG system (iCam4D). Four groups were created depending on the system used to capture the position of the implants: Grammee, MicronMapper, Elite, and IOConnect (n=10). In the Grammee group, the corresponding optical marker was tightened on each implant abutment and PG scans were recorded by using the camera of the extraoral PG system. In the MicronMapper group, an optical marker of the extraoral PG device was hand tightened on each implant abutment, and PG scans were recorded by using the camera of the system. In the Elite group, scan bodies were hand tightened on the implant abutments, and intraoral scans were captured by using the corresponding intraoral scanner (IOS) (Aoralscan Elite). Euclidean linear and angular measurements were calculated on the 10 reference scans, and the average of each was used to compare the discrepancies with the same measurements obtained on each experimental scan. One-way ANOVA and Tukey post hoc tests were used to analyze the trueness data. The Levene test was used to analyze the precision values (α=.05).

Results: Significant linear trueness discrepancies were found among the groups (P<.001). The Grammee and MicronMapper groups had the best linear trueness, while the IOConnect had the worst linear trueness. The mean linear discrepancies ranged from 20 to 48 µm among the groups. The Levene test revealed no significant linear precision discrepancies among the groups (P>.05). Additionally, statistically significant angular trueness differences were revealed among the groups (P<.001). The Elite group had the best angular trueness. The mean angular discrepancies ranged from 0.12 to 0.45 degrees among the groups. Additionally, the Levene test revealed significant angular precision discrepancies among the groups tested (P<.001). The MicronMapper and Elite groups had the best angular precision.

Conclusions: The 4 implant scanning techniques tested may provide a reliable digital data acquisition method for capturing the 3D position of implants being scanned.