title: Digital versus analog complete-arch impressions for single-unit premolar implant crowns: Operating time and patient preference.
abstract: BACKGROUND
  Digital impression-making techniques are supposedly more patient friendly and less time-consuming than analog techniques, but evidence is lacking to substantiate this assumption.
  
  
  OBJECTIVE
  The purpose of this in vivo within-subject comparison study was to examine patient perception and time consumption for 2 complete-arch impression-making methods: a digital and an analog technique.
  
  
  METHODS
  Fifty participants with a single missing premolar were included. Treatment consisted of implant therapy. Three months after implant placement, complete-arch digital (Cerec Omnicam; Sirona) and analog impressions (semi-individual tray, Impregum; 3M ESPE) were made, and the participant's opinion was evaluated with a standard questionnaire addressing several domains (inconvenience, shortness of breath, fear of repeating the impression, and feelings of helplessness during the procedure) with the visual analog scale. All participants were asked which procedure they preferred. Operating time was measured with a stopwatch. The differences between impressions made for maxillary and mandibular implants were also compared. The data were analyzed with paired and independent sample t tests, and effect sizes were calculated.
  
  
  RESULTS
  Statistically significant differences were found in favor of the digital procedure regarding all subjective domains (P<.001), with medium to large effect sizes. Of all the participants, over 80% preferred the digital procedure to the analog procedure. The mean duration of digital impression making was 6 minutes and 39 seconds (SD=1:51) versus 12 minutes and 13 seconds (SD=1:24) for the analog impression (P<.001, effect size=2.7).
  
  
  CONCLUSIONS
  Digital impression making for the restoration of a single implant crown takes less time than analog impression making. Furthermore, participants preferred the digital scan and reported less inconvenience, less shortness of breath, less fear of repeating the impression, and fewer feelings of helplessness during the procedure.
authors.affiliation: Associate Professor, Department of Fixed and Removable Prosthodontics and Biomaterials, University of Groningen, University Medical Center Groningen, Center for Dentistry and Oral Hygiene, Groningen, The Netherlands. Electronic address: u.schepke@umcg.nl.
authors.forename: Ulf
authors.initials: U
authors.lastname: Schepke
authors.affiliation: Professor, Department of Fixed and Removable Prosthodontics and Biomaterials, University of Groningen, University Medical Center Groningen, Center for Dentistry and Oral Hygiene, Groningen, The Netherlands.
authors.forename: Henny J A
authors.initials: HJ
authors.lastname: Meijer
authors.affiliation: Associate Professor, Department of Public and Individual Oral Health, University of Groningen, University Medical Center Groningen, Center for Dentistry and Oral Hygiene, Groningen, The Netherlands.
authors.forename: Wouter
authors.initials: W
authors.lastname: Kerdijk
authors.affiliation: Professor, Department of Fixed and Removable Prosthodontics and Biomaterials, University of Groningen, University Medical Center Groningen, Center for Dentistry and Oral Hygiene, Groningen, The Netherlands.
authors.forename: Marco S
authors.initials: MS
authors.lastname: Cune
mesh_terms: D001641:Bicuspid; D017076:Computer-Aided Design; D003442:Crowns; D015921:Dental Implants; D003760:Dental Impression Materials; D003761:Dental Impression Technique; D006801:Humans; D003765:Models, Dental; D057240:Patient Preference; D012117:Resins, Synthetic; D011795:Surveys and Questionnaires
chemical_list: D015921:Dental Implants; D003760:Dental Impression Materials; C022821:Impregum; D012117:Resins, Synthetic