Clinical accuracy of complete arch implant scans recorded by using a noncalibrated splinting technique, intraoral photogrammetry, and extraoral photogrammetry with snap-on markers.

Statement of problem: The selection of an implant scanning technique for recording implant positions is a critical element that impacts the implant-prosthodontic discrepancy. However, clinical studies that have analyzed the accuracy of the different implant scanning techniques are lacking. Additionally, the impact of the retention system of the markers on the accuracy of extraoral photogrammetry (PG) devices is unknown.

Purpose: The purpose of this clinical study was to compare the accuracy of complete arch implant scans captured by using intraoral and extraoral PG devices and a noncalibrated splinting method.

Material and methods: A patient with a mandibular edentulous arch with 4 osseointegrated implants with implant abutments (Multi-Abutment) participated in the study. To obtain the reference file (control), a screw-retained optical marker was hand tightened on each implant abutment, and 10 succeeding PG scans were recorded by using a calibrated extraoral PG system (Micron Mapper). Three groups were developed based on the technique used to capture the implant scans: MicronMapper, Elite, and IOConnect (n=10). In the MicronMapper group, a snap-on optical marker of the extraoral PG device was positioned on each implant abutment, and PG scans were recorded with the camera of the PG 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). In the IOConnect group, scan bodies were hand tightened on the implant abutments connected in the center of the arch, and intraoral scans were captured by using an IOS (TRIOS 5). Euclidean linear and angular measurements were calculated on the 10 reference scans, and the average was used to compare the discrepancies with the same measurements obtained on each experimental scan. One-way ANOVA and Tukey tests were used to analyze the trueness data. The Levene test was used to analyze the precision values (α=.05).

Results: Linear precision discrepancies were found among the groups tested (P=.008). The IOConnect group had significantly better linear precision than the MicronMapper and Elite groups (P=.017). Additionally, significant angular trueness differences were found among the groups tested (P<.001). The MicronMapper and Elite groups (P<.001) and Elite and IOConnect (P<.001) were significantly different from each other. The Elite group had the best angular trueness. Moreover, the Levene test demonstrated significant angular precision discrepancies among the groups tested (P=.026). The MicronMapper and Elite groups had the best angular precision.

Conclusions: The implant scanning technique tested impacted the trueness and precision of complete arch implant scans.