Objectives: The European Union’s Medical Devices Directive (Directive 93/42/EEC) places legal and ethical obligations on dental practitioners to adequately design, prescribe and fabricate good quality prostheses. The purpose of this investigation was to examine the quality of written instructions and choice of impression trays and materials for both fixed and removable prosthodontics in Ireland.

Methods: A pre-piloted questionnaire was distributed to a number of large commercial laboratories geographically distributed throughout Ireland. Information was sought relating to the quality of written instructions and use of impression trays and materials for three forms of ‘dental precision casting’- cobalt-chromium based removable partial dentures (RPDs), full veneer porcelain-fused-to-metal crowns (PFMs), and fixed bridges (FBs). Descriptive statistics are reported.

Results: Information was received relating to 301 items, of which 48% (n=145) related to PFMs, 32% (n=96) related to FBs, and 20% (n=60) related to RPDs. All items were privately funded. 49% (n=148) of master impressions were made using a plastic stock tray (32% of RPDs, 55% of PFMs, 52% of FBs). Poor or no written instructions were provided in 52% (n=157) of cases (65% of RPDs, 65% of PFMs, 25% of FBs). The technician felt that master impressions had been appropriately disinfected prior to being sent to the laboratory in 78% of cases.

Conclusion: The written instructions and master impressions examined in this study failed to meet the relevant ethical and legal requirements in over half of cases examined. Further investigation into the reasons for this is warranted.