Laboratory contamination of dental prostheses

I n prosthodontics, several materials, instruments, and pieces of equipment are used which cannot be sterilized. Thus a potential for bacterial crosscontamination between the dental operatory and the prosthetic laboratory has been established, constituting a potential health hazard in prosthodontic practice.’ Laboratory bacterial cross-contamination among denture patients was demonstrated by Katberg.* Specific sources and pathways of cross-contamination within the dental laboratory were identified by Clarke et al3 and Fisher et al.” As a result of these findings, safety guidelines were developed and outlined in the Occupational Health and Safety Act.” On the basis of Clark’s study, a sanitation-hygiene code for dental laboratories was approved by the National Association of Dental Laboratories in 1970. The recommendations of the study stated, “Acceptable sanitation practices in transporting articles to and from the laboratory, and in processing articles within the laboratory itself, can significantly reduce the health hazard to laboratory and other workers, minimize cross-contamination of appliances and assure that a sanitary product is delivered to the dental office for the patient.“3 Specific guidelines were established to be followed for all phases of laboratory work, and voluntary compliance was encouraged. It was suggested that all finished dental prostheses be placed in sealed plastic bags containing a disinfectant solution, labeled, and accompanied by instructions to rinse the prosthesis prior to delivery to the patient. Regrettably, hygiene in many laboratories continues to be substandard which suggests the need for more stringent control measures. The dentist is faced with the possibility of contamination of prostheses