Effectiveness of various decontamination methods on CAD/CAM camera mirror sleeves.

AIM: The purpose of this study was to evaluate the effectiveness of several methods of disinfection and sterilization of computer-aided design/computer-aided manufacturing (CAD/CAM) camera mirror sleeves (Omnicam; Dentsply Sirona).

MATERIALS AND

METHODS

The outer surface of seven groups of mirror sleeves were inoculated by submerging them in suspensions of Staphylococcus aureus and Pseudomonas aeruginosa. Post inoculation, the groups were decontaminated as follows: Group A: no decontamination or sterilization following inoculation (positive control); Group B: surface cleaning with a neutral soap (Dawn Dish Soap, Procter & Gamble) and water only; Group C: surface disinfection with 17% isopropanol (CaviWipes; Metrex). Groups D to F received a different high-level disinfection (HLD) solution in an HLD container (Dentsply Sirona) as follows: Group D: 0.55% ortho-phthalaldehyde (OPA) (Cidex OPA; Johnson & Johnson); Group E: 7.5% hydrogen peroxide (H2O2) (Sporox II; Sultan); Group F: 7.35% H2O2 and 0.23% peracetic acid (PAA) (Compliance; Metrex). Group G received dry-heat sterilization (Rapid Heat Sterilizer; Cox). Also, dry-heat sterilized mirror sleeves that were not exposed to bacteria and not disinfected served as a negative control. The presence of bacteria was tested on the inside and outside of the sleeves by plating samples on TSA II. A percent reduction in CFU/ml from the positive control group was determined per group.

RESULTS

All methods of disinfection except Dawn Dish Soap resulted in greater than 99.99% reduction in CFU/ml compared with the positive control group.

CONCLUSIONS

Both HLD or dry-heat sterilization resulted in no growth of microorganisms in cultures taken from both the outside and inside surfaces of the bacteria-contaminated mirror sleeves.