Assessing the quality of clinical procedures and technical standards of dental laboratories in fixed partial denture therapy.

PURPOSE: This study was conducted to assess the quality of impressions and tooth preparations sent to dental laboratories in Jordan and to determine the technical capabilities of these laboratories to construct fixed partial dentures.
MATERIALS AND METHODS: A sample of 136 impressions and stone casts were examined for clinical errors in 35 laboratories that construct fixed partial dentures. They were sorted into unusable, unsatisfactory, acceptable, or satisfactory categories. The type of impression material and tray, opposing arch impressions, and occlusal records were noted. Instructions to technicians were assessed for completeness and clarity. Information regarding laboratory staff and equipment were collected.
RESULTS: Half of the specimens inspected were categorized as unusable or unsatisfactory; these were found in commercial laboratories. They showed at least one clinical error such as drags or indefinite finishing lines in impressions and inadequate reduction, undercuts, or obvious taper on stone casts. Alginate impression material was used for 65% of the cases. Only 27% of specimens were accompanied with instructions; of these 22% were graded poor. No occlusal records were available with 54% of the specimens and no articulators were used except in dental school laboratories. The dental schools and some commercial laboratories had the best staff and equipment and were more capable of fabricating fixed partial dentures than those of the Ministry of Health and the Royal Med cal Services.
CONCLUSION: The quality of abutment preparation and impressions were unsatisfactory or unusable in 50% of cases. Of the 37 available instructions 8 were not clear. The dental schools and some commercial laboratories were technically capable of producing good quality fixed partial dentures.