title: The quality of impressions for crowns and bridges received at commercial dental laboratories.
abstract: OBJECTIVE
  To determine the quality of impressions for crown and bridge work made in general dental practice.
  
  
  METHODS
  All impressions for crown and bridge work which had been sent to four commercial dental laboratories in the UK were assessed by two examiners, each laboratory being visited on two occasions.
  
  
  METHODS
  290 cases which had been received by the laboratories on the days of the visits were assessed for a number of factors related to quality. There was no selection or rejection--all impressions received were examined.
  
  
  RESULTS
  Flexible plastic trays were used for the majority of working impressions for crown and bridge work in general dental practice (72%), many had been re-used (> 13%), defects in the recording of the prepared teeth were common, and cross infection control was not routine.
  
  
  CONCLUSIONS
  Quality standards for impressions for crown and bridge work in general dental practice in the UK are a cause for concern if the sample of cases seen in this study is typical.
authors.affiliation: Department of Restorative Dentistry, School of Clinical Dentistry, University of Sheffield.
authors.forename: R B
authors.initials: RB
authors.lastname: Winstanley
authors.forename: P V
authors.initials: PV
authors.lastname: Carrotte
authors.forename: A
authors.initials: A
authors.lastname: Johnson
mesh_terms: D003442:Crowns / Q000592:standards*; D003760:Dental Impression Materials; D003761:Dental Impression Technique / Q000295:instrumentation / Q000592:standards*; D003779:Denture Design / Q000592:standards; D003829:Denture, Partial / Q000592:standards*; D004203:Disinfection; D004739:England; D004867:Equipment Design; D017743:Equipment Reuse; D005792:General Practice, Dental; D006801:Humans; D017053:Infection Control; D007284:Inlays / Q000592:standards; D007574:Jaw Relation Record; D007754:Laboratories, Dental; D010969:Plastics; D011176:Post and Core Technique / Q000592:standards; D055656:Prescriptions / Q000592:standards; D011787:Quality of Health Care; D013499:Surface Properties; D019231:Tooth Preparation, Prosthodontic / Q000592:standards
chemical_list: D003760:Dental Impression Materials; D010969:Plastics