The role of needle purging in reducing transfer of microorganisms from local anesthetic cartridge diaphragms.

The literature is reviewed to demonstrate the significant amount of contamination on the external surface of the anesthetic cartridge diaphragm. Current methods of cartridge diaphragm decontamination to prevent injection of pathogens are discussed. A series of bacteriologic tests were conducted to determine the probability of transfer of pathogens from the diaphragm surface through the needle lumen of three different sizes to the deposition site. Results of needle purging suggest that a significant reduction in the transfer of microorganisms is possible using this technique.