In vitro evaluation of cleaning efficacy of detergents recommended for use on dental instruments

BackgroundThe cleaning stage of instrument decontamination processes is a critical control point, and removal of protein deposits is used as a marker of cleaning efficacy. An important factor is the choice of cleaning solution especially in the absence of any defined standards for detergent effectiveness.MethodsFollowing method validation, stainless steel tokens were inoculated with reconstituted citrated blood and added to a 24-multiwell plate and immersed in different cleaning solutions for 5 minutes, agitated at 25 (20°) tilts/min at 22°C and at the manufacturers' recommended temperatures. Desorbed protein was measured using the bicinchoninic acid assay.ResultsFrom a starting concentration with a median of 3,700 μg of blood protein of all solutions tested, alkaline detergent (Haemo-sol) removed the largest proportion of protein (median, 2,070 μg), and surgical handwash removed the least protein (median, 0 μg). Reverse osmosis water demonstrated useful blood-removing properties with a median of 1,421 μg.ConclusionThe cleaning system we utilized is a simple, inexpensive method to compare the cleaning efficacies of detergents and may be used as a first stage in benchmarking cleaning efficacy of detergents. Not all solutions used in cleaning dental instruments are efficacious at removal of blood.