Validity, Reliability, Reproducibility of Full-arch Digital Impressions: a Systematic Review

Methods: An electronic search was conducted through PubMed database using the following keywords: “digital impression*” with “journal category - dental journals” filter, “intraoral digital impression*”, “intraoral scan*”. No language or time limitation was applied. The retrieved items were screened based on a three-stage revision that subsequently considered titles, abstracts, and full texts. Only studies dealing with full-arch impressions were considered. Reference lists of the selected studies were also searched for potentially relevant research.

Results: In only 7 of the published studies complete-arch scans had been performed intraorally, rather than on dry skulls, reference models or conventional impressions. Of these 7 studies only 3 papers reported data on validity, reliability, and reproducibility of digital measurements, while the other ‘in vivo’ investigations focused on scanning times, patients’ perception, fit of orthodontic retainers. Only 2 of the marketed scanning systems have so far been tested under clinical conditions.

Conclusions: The evidence on the effectiveness of full-arch digital impressions should be strengthened with ‘in vivo’ trials of the several currently available scanning systems. Also, further information should be collected on the validity of intraoral scans performed in children, as well as on their attitude towards this new technique.