Comparative study of the accuracy of an implant intraoral scanner and that of a conventional intraoral scanner for complete-arch fixed dental prostheses

Abstract

Statement of problem: Most of the available digital systems are designed to image teeth and soft tissue rather than dental implants. However, although some are marketed specifically to record implant position, whether these products are better for implant scanning is unclear.

Purpose: The purpose of this in vitro study was to compare the accuracy of an implant intraoral scanner (PiC camera) with that of an intraoral scanner (TRIOS 3) for 6 implants placed in completely edentulous arches.

Material and methods: Two maxillary master models with 6 external hexagonal Ø5.1-mm implants were used, one with parallel and the other with angled implants. The reference values were obtained with a coordinate measuring machine. Ten scans were made per model (parallel and angled) and system (intraoral and implant) (n=10), after which the 3-dimensional coordinates for each implant were determined with a computer-aided design software program and compared with the linear and angular reference values. Statistical significance was determined with the Student t test (α=.05).

Results: Statistically significant differences (P<.001) were found in both precision and trueness. The overall errors relative to the reference in the parallel implant-supported casts based on the implant scanner were 20 μm (P=.031) and 0.354 degrees (P=.087) compared with 100 μm (P<.001) and 1.177 degrees (P<.001) in the cast based on conventional digital scans. The global errors in the angled implant casts were 10 μm (P=.055) and 0.084 degrees (P=.045) for the implant digital scans and 23 μm (P=.179) and 0.529 degrees (P<.001) for the conventional digital scans.

Conclusions: The implant intraoral scanner delivered greater precision and trueness than the conventional instrument for imaging complete-arch implant-supported prostheses.