September 2007 ■ Journal of Dental Education 1223 Infection Control Procedures in Commercial Dental Laboratories in Jordan Ziad Nawaf Al-Dwairi, B.D.S., Ph.D. Abstract: The risk of cross-infection in dental clinics and laboratories has attracted the attention of practitioners for the past few years, yet several medical centers have discarded compliance with infection control guidelines, resulting in a non-safe environ- ment for research and medical care. In Jordan, there is lack of known standard infection control programs that are conducted by the Jordanian Dental Technology Association and routinely practiced in commercial dental laboratories. The aim of this study was to examine the knowledge and practices in infection control among dental technicians working in commercial dental laboratories in Jordan. Data were collected from the dental technicians by a mailed questionnaire developed by the author. The questionnaire asked respondents to provide demographic data about age and gender and to answer questions about their knowledge and practice of infection control measures: use of gloves, use of protective eyeglasses and face shields, hepatitis B virus (HBV) vaccination, laboratory work disinfection when sent to or received from dental offices. and regularly changing pot water or pumice slurry. Of the total respondents, 135 were males (67.5 percent) and sixty-five were females (32.5 percent) with a mean age of twenty- seven years. The results showed that 24 percent of laboratory technicians wore gloves when receiving dental impressions, while 16 percent continued to wear them while working. Eyeglasses and protective face shields were regularly worn by 35 percent (70/200) and 40 percent (80/200) of technicians, respectively. Fourteen (14 percent) had received an HBV vaccination, and 17 percent inquired if any disinfection measures were taken in the clinic. Eighty-six percent of the technicians reported that pumice slurry and curing bath water were rarely changed. Only five dental technicians (two males and three females) were considered to be fully compliant with the inventory of infection control measures, a compliance rate of 2.5 percent with no significant differ- ence between males and females (p>0.05). In conclusion, there is lack of compliance with infection control procedures of dental technicians working in commercial laboratories in Jordan. Dr. Al-Dwairi is Assistant Professor, Department of Restorative Dentistry, Jordan University of Science and Technology. Direct correspondence and requests for reprints to Dr. Ziad Nawaf Al-Dwairi, Department of Restorative Dentistry, Jordan University of Science and Technology, P.O. Box 3030, Irbid-Jordan; ziadd@just.edu.jo. Key words: infection, dental, technician, laboratory, Jordan Submitted for publication 1/24/06; accepted 6/7/07 T here is growing concern about the issue of cross-infection in dental clinics and labora- tories, especially after several studies found that transmission of infection to dental laboratory technicians is mainly by contaminated impressions or by improper handling of clinical items after arrival at the dental laboratory. Three studies published in 1990, 1996, and 2002 reported that more than 60 percent of prostheses delivered to dental clinics from laboratories were contaminated with patho- genic microorganisms originating in the oral cavity of patients. 1-3 In prosthetic laboratories, lathes and pumice used for polishing and finishing of prosthe- ses have been described as the greatest sources of contamination. 4 Potential pathogenic microbiologic cross- contamination from various sources by way of the dental laboratory has been documented, and guide- lines to reduce it have been published. 5 A previous study reported that nine out of ten sterile complete dentures that were fractured and sent to different dental laboratories for repair were contaminated with potentially pathogenic microorganisms. 6 Several studies have found pumice in commercial laborato- ries that was contaminated by potentially pathogenic microorganisms, such as gram-negative bacilli of the genus Acinetobacter, as well as Micrococcus, Pseudomonas, Moraxella, and Alcaligenes. 6-8 These bacteria, which are not part of normal oral flora, can cause serious diseases if passed to patients whose dentures are polished with contaminated material and to the technician by exposure to contaminated aerosol. Williams et al. 9 reported an increase in cases of pneumonia in individuals exposed to lathe aero- sol. Another study reported ten cases of infection by Mycoplasma pneumoniae involving persons working in dental prosthetic laboratories; the investigators suspected that these infections were derived from manipulation of prostheses contaminated by these microorganisms. 10 Dental prostheses should be disinfected before they are sent to the laboratory and upon return to the dental clinic. However, despite rigorous control of sterilization and disinfection of instruments in dental clinics, prosthetic appliances do not always receive adequate infection control. 11