Digital and conventional impressions have similar working times.

Data sourcesMedline, Cochrane, Science Direct, Scopus and Embase were electronically searched and complemented with hand searches. Studies published from 1955 to July 2016 were considered.Study selectionClinical studies (prospective, retrospective and RCTs) relating to digital implant or tooth impression techniques, comparing patient reported outcome measures (PROMs) and procedure working times compared to conventional impression techniques were considered. The following exclusions were adhered to; in vitro studies, ex vivo studies, systematic reviews, clinical cases, animal studies and any studies not comparing digital and conventional impression techniques.Data extraction and synthesisData extraction was carried out independently by two reviewers. Risk of bias assessment was conducted using the Cochrane tool for RCTs and a modified Newcastle-Ottawa scale for non-RCTs. In all 2943 publications were reviewed following the initial electronic search, of which 2916 were excluded at this stage. A qualitative analysis was conducted.ResultsFive studies were included; all three of the RCTs included were at high' risk of bias and the observational studies were judged to have a methodology of medium quality. Given the differences in the studies, a meta-analysis could not be performed. Three studies conducted involved implant supported prostheses only, two reported on tooth supported prostheses with a total of 155 participants included. Four studies comparing PROMs between the different impression techniques reported, a digital impression technique reduced anxiety and nausea, being considered more comfortable than a conventional impression technique. The remaining study reported no difference in patient comfort when comparing techniques. With respect to procedure working time three studies reported that the digital impression technique required less time; conversely two studies reported less time for the conventional technique.ConclusionsThis systematic review draws two conclusions; working times are similar for both conventional and digital impression techniques and patients prefer the experience of digital to conventional impressions. It does acknowledge the lack of relevant studies in this area.