Efficacy of Various Sterilization Techniques on Diamond-Coated Dental Burs

Objectives: The objective of this study was to evaluate the effectiveness of various combinations of debriding, washing, ultrasonic cleaning and sterilization methods on the sterilization of contaminated and inoculated diamond-coated burs.
Methods: Diamond-coated burs (6856.31.018 FG Coarse Round-End Taper Diamond, Brasseler) and extracted human third molars were sterilized with a steam sterilizer (Amsco 400, Steris). Enamel and dentin from the extracted teeth were abraded with the diamond-coated burs for 30 seconds with a high-speed handpiece. The burs were subsequently inoculated with one of the following microorganisms: Enterococcus faecalis ATCC 19433, Staphylococcus aureus ATCC 6538, or Pseudomonas aeruginosa ATCC 15442. Twenty-four hours after inoculation, the burs were subjected to various sterilization treatments and then cultured for bacterial contamination. Twenty burs were used per group. See table below. For a positive control group, burs received no decontamination or sterilization after immersion in the bacterial suspension. A negative control group with no bacterial exposure and no decontamination was conducted on manufactured prepackaged unused burs and cultured for the presence/absence of bacteria. The number of CFU/mL was determined per group.
Results: Except for the positive control, no CFU/mL or no growth was found for all treatment groups and for all bacterial types. None of the prepackaged unused burs demonstrated any bacterial growth.
Conclusions: The contaminated and inoculated diamond-coated burs tested in this study may be successfully sterilized to eliminate the tested bacteria.