Infection Control: Then and Now
John A. Molinari, PhD
If time travel were possible, it would be interesting to observe how a dentist, hygienist, and assistant from a practice circa 1980 would react if they were transported to a dental practice in 2019. Chances are they would be quite surprised by the additional precautions and procedures today's dental professionals perform on a daily basis. The following discussion will review a few of the changes they might notice.
Personal Protection: The first and most obvious difference the time travelers would see today would be gloves, face masks, and protective eyewear worn by everyone treating patients. Using gloves as an example, the majority of dental team members started wearing gloves for patient care in the mid-1980s. The American Dental Association first approached this topic in a 1976 article published in The Journal of the American Dental Association. It was aimed at protecting dental healthcare providers from what is still the most infectious bloodborne occupational pathogen, the hepatitis B virus. Dental colleagues did not realize back then that they would soon adapt and change from "wet finger dentistry" to "barrier-protected dentistry" and be safer because of it.
Asepsis and Instrument Pro-cessing: As the time travelers would be escorted into today's clinical operatories by an infection control assistant, they would find instruments in pouches, cassettes on bracket trays ready for patient care, wrapped sterilized instruments that are stored in designated cabinet drawers, and fewer loose items on counter surfaces. As surprising as these changes would appear to them, an even more surprising change would be seen when they entered the area where contaminated instruments are reprocessed for patient care. They would notice the absence of the familiar glutaraldehyde sterilization container, where they cold sterilized a number of items in their practice. Instead, the dental team from the past now would see a designated instrument reprocessing area, where the overwhelming majority of treatment items are heat sterilized and other heat-labile items are replaced with single-use disposables.
In the practice world of 40 years ago, contaminated instruments were often cleaned manually with a scrub brush. Accidental sharps exposures were not uncommon during these procedures; postexposure treatment often stopped after handwashing, and incidents were infrequently reported for follow-up. Although ultrasonic cleaners designed for mechanical removal of debris were found in most dental practices, a number of dental personnel still relied on hand scrubbing as the final cleaning step before sterilization. Ultrasonic units were not periodically checked to determine whether they were functioning properly. Ultrasonic cleaning solutions may have been changed only weekly, or as one descriptor stated, "when the unit solution becomes cloudy after use."
Now, the time travelers would observe that the solutions used to clean contaminated items are changed at least daily, and the cleaning efficiency of the equipment is periodically monitored using aluminum foil or commercial test strips impregnated with artificial organic soil. They would note that the risky procedure of hand scrubbing instruments is rarely used. It has been replaced by a large ultrasonic unit and a built-in piece of equipment, which the infection control assistant calls an instrument washer. "Do not confuse this unit with a dishwasher," she tells them. "Instrument washers are developed, tested, and FDA-registered to clean sensitive medical instruments. Again, they are not to be confused with dishwashers, which are designed to clean dishes and some pots and pans."
The assistant goes on to tell her colleagues from the 1980s how the practice's autoclaves are monitored weekly using calibrated spore testing, as recommended by the Centers for Disease Control and Prevention, to ensure equipment is working properly. She even mentions that within the last year, the practice began using strips called class V integrators to monitor each sterilization cycle. These strips contain a thin tube with chemical ink that reacts to the parameters of temperature, pressure, and time during the sterilization cycle. "They do not take the place of the required weekly biologic spore test monitoring," she says, "but we can pick up sterilization cycle failures much more rapidly and correct problems by using these integrators as an adjunct to our biologic monitoring system."
After they return to their own time and compare their experiences, the 1980 dental care providers would realize that they have glimpsed the future of infection control in dentistry. A list comparing what they were used to doing and what 21st century dental practices routinely perform is shown in Table 1. Today's dental professionals take many procedures for granted, but the following should be noted: You must remember where you came from, in order to know where you are, as you prepare for the future.