Can Oral Debris on Dental Instruments Harbor Organisms from Disinfection?

Background and Aim: Reusable dental instruments are continually contaminated with debris and body fluids, which require cleaning decontamination and sterilization prior to re-use. This study was aimed to assess if remaining blood and debris on instruments can prevent instruments from being fully disinfected and sterilized because of harboring microorganisms and impeding disinfectant penetration. Materials and Methods: 42 unwashed contaminated instruments were collected in the case group, while 42 washed contaminated instruments formed the control group. Samples were collected in 2 separate sterile trays, and then submerged in 2% Hydrogen Peroxide (NanoSil) for 3 hours. Sterile swabs impregnated with Trypticase Soy Broth (TSB) were used for sampling. Specimens were transferred to mediums before incubating for 24 hours at 37°C. Samples with bacterial growth were transferred to blood agar, chocolate agar and McConkey agar to identify bacterial species. Results: There was 100% absence of bacterial growth in control samples, while unwashed instruments showed 28.6% (12 samples) presence of growth. Conclusion: This study indicates that remaining blood and debris on instruments may shelter microorganisms. Thus soaking contaminated instruments in disinfectant within the required time and washing them properly via a mechanical system before autoclaving, develops a discreet, secure sterilizing method with the highest success.