Accuracy of photogrammetric imaging versus conventional impressions for complete-arch implant-supported fixed dental prostheses: A comparative clinical study

Published:November 11, 2021

Abstract

Statement of problem

Clinical studies on the accuracy of the photogrammetric imaging technique for complete-arch implant-supported fixed dental prostheses are lacking.

Purpose

The purpose of this clinical study was to evaluate the accuracy (trueness) of photogrammetric imaging for complete-arch implant-supported prostheses by comparing photogrammetric imaging with verified conventional splinted impressions.

Material and methods

Completely edentulous arches with at least 4 implants were included. Both photogrammetric imaging and conventional splinted impressions were performed in each jaw. The conventional casts were verified and scanned by using a laboratory scanner as the control. The distances and angulations between different implants (interimplant distances and interimplant angulations) were measured in all photogrammetric and conventional standard tessellation language (STL) files by using a reverse-engineering software program. The distance deviations between the photogrammetric and conventional impressions of the same participant were calculated as the primary outcome, and the angular deviations were obtained as the secondary outcome with descriptive analyses. The comparison between distance deviations and the clinically acceptable level of deviations (150 μm) was conducted by using the 1-sample t test. The effect of interimplant distances, interimplant angulations, and jaw (maxilla or mandible) on deviations was analyzed by using the Spearman correlation analysis, Kruskal-Wallis test, or Student t test, depending on the type of data (α=0.05 for all tests).

Results

Fourteen edentulous jaws were included. The overall distance deviation of photogrammetric imaging was 70 ±57 μm, significantly lower than the clinically acceptable level of misfit (150 μm; P<.001). The overall angular deviation was 0.432 ±0.348 degrees. The distance deviations were correlated with interimplant distances with a correlation coefficient (r) of 0.371 (P=.002). Interimplant angulation was not correlated with distance or angular deviations (P=.914, P=.914). Jaw was not correlated with distance or angular deviations either (P=.190, P=.209).

Conclusions

The accuracy (trueness) of photogrammetric imaging of complete-arch implant-supported prostheses was within a clinically acceptable range of errors. Distance deviations increased with greater interimplant distances. Interimplant angulations and jaw (maxilla or mandible) had no significant effect on the accuracy of photogrammetric imaging.