Long-term sterility of orthodontic-surgical appliances.

The aim of this study was to evaluate the long-term sterility of new dental appliances according to the non rigid wrapping employed and assess the effectiveness of sterilization in a steam autoclave at 134 degrees for 20 minutes using physical, chemical, and biological indicators. All the experimental (E) samples and the control samples (C) were assigned to one of three groups according to the type of packaging: paper bag (E1), paper/plastic pouch (E2), nylon tubing bag (E3). Each bag contained standardized orthodontic wires and brackets and sterility indicators. The samples were evaluated at the following experimental times: immediately, and 6, 12, 24 and 30 months post-sterilization. The samples were analyzed under aerobic and anaerobic conditions in keeping with the protocol currently in use at the Department of Microbiology, School of Dentistry, University of Buenos Aires. The group of control, non-sterilized samples (C1, C2, C3) were analyzed prior to the onset of the study, and were found to be contaminated. None of the sterilized samples in any of the three experimental groups evidenced contamination at any of the experimental times. The results showed that, under the present conditions, the packages and orthodontic appliances remained sterile for 30 months. These results show the importance of controlling sterility and the storage conditions over time for all the orthodontic/surgical appliances used in invasive treatments.