A Survey of Methods Used to Treat Contaminated Orthodontic Instruments: And an Experimental Comparison of the Three Cleaning Methods Most Commonly Used

Abstract

This study involved two areas of investigation. First, questionairres were sent to 350 orthodontists in order to determine the types and frequency of methods used to treat contaminated instruments in their practices. Two hundred eighty replies were received. Second, using orthotolidine reagent strips, three commonly-used cleaning methods (alcohol wipe, soap and water scrub, and ultrasonic cleaning) were compared as to their effectiveness in the removal of a potentially dangerous contaminant, blood, from a representative orthodontic instrument, the band pusher. A sample of 15 instruments was tested.

The survey showed that a variety of cleaning, disinfecting, and sterilizing procedures were used in various combinations in the practices surveyed. Less than 4.3% of the respondants treated hand instruments -- the group most likely to be contaminated with blood -- in a manner acceptable to various authorities on the subject, such as: The Expert Committee on Hepatitis of the World Health Organization, the United States Institutes of Health, and The Council on Dental Therapeutics of the American Dental Association.

Of the three cleaning methods tested, ultrasonic cleaning was the most effective for removing blood from the test instruments, and alcohol wiping was least effective. Both alcohol wiping and soap and water scrubbing left detectable amounts of blood on all instruments tested.

Since: a) orthodontic instruments may be contaminated with blood during routine treatment procedures, b) asymptomatic carriers of serum hepatitis may constitute at least 1% of the population, and the viruses of both forms of viral hepatitis may be found in the serum of 5 - 35% of apparently healthy persons, c) as little as .00005 ml of infected blood is capable of transmitting the disease, and d) a high percentage of the sample of orthodontists responding used inadequate methods to treat their instruments, the danger of transmission of viral hepatitis exists in the great majority of orthodontic practices surveyed in this study.