From Registred Dental Hygenist web site By Lory Laughter, RDH, BS, MS ... Are disposable items sterile? "This review leads to a very important point of question. If items that come into contact with mucosal tissues are to be sterile, why are single-use disposable items used in dentistry not normally sterilized? I've worked in practices where 2x2 gauzes were sterilized prior to use in surgical situations. When gauze is used in the oral cavity, it makes sense that it should be sterile, not introducing microorganisms with the potential to cause infection. Yet, unsterile single-use burs, saliva ejectors , lip retractors, and prophy angles are the norm. A study published in The Dental Advisor (March 2012) demonstrated unsterile pre-packaged burs showed bacterial colony growth when cultured on blood agar plates. In contrast, pre-sterilized burs showed no bacterial growth. During the study, burs were exposed to a broth containing 5% sheep's blood for 30 secon...