Quality of Impressions and Work Authorizations Submitted by Dental Students Supervised by Prosthodontists and General Dentists

Abstract

Preclinical fixed prosthodontics is taught by Department of Prosthodontics faculty members at Virginia Commonwealth University School of Dentistry; however, 86% of all clinical cases in academic year 2012 were staffed by faculty members from the Department of General Practice. The aims of this retrospective study were to quantify the quality of impressions, accuracy of laboratory work authorizations, and most common errors and to determine if there were differences between the rate of errors in cases supervised by the prosthodontists and the general dentists. A total of 346 Fixed Prosthodontic Laboratory Tracking Sheets for the 2012 academic year were reviewed. The results showed that, overall, 73% of submitted impressions were acceptable at initial evaluation, 16% had to be poured first and re-evaluated for quality prior to pindexing, 7% had multiple impressions submitted for transfer dies, and 4% were rejected for poor quality. There were higher acceptance rates for impressions and work authorizations for cases staffed by prosthodontists than by general dentists, but the differences were not statistically significant (p=0.0584 and p=0.0666, respectively). Regarding the work authorizations, 43% overall did not provide sufficient information or had technical errors that delayed prosthesis fabrication. The most common errors were incorrect mountings, absence of solid casts, inadequate description of margins for porcelain fused to metal crowns, inaccurate die trimming, and margin marking. The percentages of errors in cases supervised by general dentists and prosthodontists were similar for 17 of the 18 types of errors identified; only for margin description was the percentage of errors statistically significantly higher for general dentist-supervised than prosthodontist-supervised cases. These results highlighted the ongoing need for faculty development and calibration to ensure students receive the highest quality education from all faculty members teaching fixed prosthodontics.Dr. Imbery is Associate Professor,

The quality of undergraduate crown and bridge impressions: a three-cycle audit

“…Over the audit period, the overall proportion of satisfactory working impressions and those with only minimal defects increased to 85% which is very encouraging and compares very favourably to many previous studies. 4,5,6,7,8,12,13,18 This paper reinforces the benefits of clinical audit and provides a contemporary benchmark from which further studies can be undertaken.…”

“…Deficiencies in the quality assurance process has been reported elsewhere. 18 The subsequent action plan (Table 5) sought not only to review the undergraduate teaching, but to focus on the quality assurance process. Illuminated magnifiers were provided for use on clinic and staff were asked to check all impressions with these magnifiers or loupes.…”

“…Whilst there is still room for improvement, if the proportion of 'satisfactory' and 'minimal defect' impressions are combined, the cycle of three audits and implemented action plans have ensured that 85% of sampled impressions were acceptable, which compares extremely favourably with previous studies. 4,5,6,7,8,12,13,18 This audit has limitations. Each sample of 100 impressions was assessed by different examiners which decreases the standardisation and reliability of results across the three audits.…”

“…A recent study at the Virginia Commonwealth University School of Dentistry found 27% of unsatisfactory undergraduate impressions were submitted by qualified general practitioner supervisors. 18 The inability for a technician to construct a restoration from an inadequate impression or failure of a constructed restoration to fit will have both clinical and financial implications, and it is therefore in the interest of all stakeholders to ensure that impressions made are of the highest quality.…”

Laboratory Technician Assessment of the Quality of Single‐Unit Crown Preparations and Impressions as Predictors of the Clinical Acceptability of Crowns as Determined by the Treating Dentist: Findings from the National Dental Practice‐Based Research Network

“…Beier et al also found a high level of clinically acceptable impressions; of 1466 impressions evaluated in this University setting, only 3% were clinically unacceptable . Findings from another University suggest a similar low incidence of unacceptable impressions at 4% . None of these studies correlated the quality of the impressions to the clinical fit of the crowns made from these impressions.…”