Capability of seven intraoral scanners to reproduce interdental spaces between two adjacent veneer preparations

Abstract

Statement of problem: Intraoral scanners (IOSs) can be used to fabricate tooth-supported restorations. The bridge scanning error appears in the interproximal space between the proximal surfaces of adjacent teeth that have a diastema. However, the interdental space threshold that IOSs are capable of reproducing without presenting the bridge scanning error is unknown.

Purpose: The purpose of this in vitro study was to assess the capability of different IOSs to reproduce interdental spaces between 2 adjacent veneer preparations.

Material and methods: A virtual model encompassing the maxillary right to the left canine was designed. Both central incisors had a veneer preparation. The virtual design was duplicated 5 times. On each model, a space was created between the veneer preparations (from 0.1 to 0.6 mm), and each cast was printed and duplicated in dental stone. The interdental space was modified with polishing strips and checked with calibrated interproximal gauges. Six groups were created depending on the space (0.1, 0.2, 0.3, 0.4, 0.5, and 0.6 mm) tested and the 7 subgroups based on the IOS examined: i700, TRIOS 5, Primescan, Freedom Air, Elite, iTero Element 5D Plus, and iTero Lumina (n=10). Each specimen was evaluated: no error, partial error, and complete error between veneer preparations. The Fisher test was used to compare the outcome (complete, partial, and no error) among the subgroups tested (α=.05).

Results: No association was found between the 0.6- and 0.5-mm interdental space and no bridge scanning error (P>.999). Additionally, no association was found between the 0.1-mm interdental space tested and the complete bridge scanning error (P>.999). However, for the 0.4, 0.3, and 0.2 subgroups, a significant association was found between the corresponding space and the partial or complete scanning error (P<.001).

Conclusions: The interdental space reproduction capabilities depended on the mesiodistal dimension of the space and IOSs selected. All the IOSs tested were able to reproduce the 0.6- and 0.5-mm space, but none of the IOSs were capable of reproducing the 0.1-mm interdental space. Additionally, only the iTero Lumina and Freedom Air systems were capable of reproducing the 0.2-mm space between veneer preparations. The interdental space reproduction threshold for the iTero Lumina and Freedom Air systems was 0.2 mm, for the TRIOS 5, i700, Primescan, and Elite systems 0.4 mm, and for the iTero Element 5D 0.5 mm.