The Canadian Journal of Dental Technology
IDS Special Issue - April 1999

What do we know today about disease transmission that we did not 10 years ago? More importantly, the transition from knowing to doing something about it has taken a serious amount of time.

Where were you 10 years ago in Infection Control? Where are you now?

Dental clients are very aware of disease transmission today. If a technician in a laboratory has an illness, what are the chances he could pass it on to the patient that will be wearing that prosthetic tomorrow? Or, in reverse, what are the chances blood from an impression may contain pathogenic bacteria or viruses? We have known for years that Dental Technicians have had a greater occupational risk of Hepatitis B than Dentists or Auxiliaries.

It used to be that the word Disinfection was only heard in surgery rooms in hospitals. We all knew there were bacteria somewhere out there, but they never, ever came close to affecting our lives. Bacteria and viruses are too small to be seen, in fact they have to be in millions before we can recognize them as a colony. We never realize the power of microbes until we are affected by them. We all can imagine someone coughing in your face, then realizing three days later that was the source of your cold. These were the situations we tried to avoid. Then many of us started to slowly realize that some colleagues and acquaintances over time had had problems with disease that were occupationally oriented. How did they get infected? Why was it not obvious at the time?

Reservoirs of Infection

All infections have an incubation period. The most difficult concept for us to fathom is that microbes are truly invisible and that every time we have contact with microbes, we become infected. Now, becoming infected does not always lead to sickness or disease. After infection our immune system fights the invading microbes with varying degrees of success. This Incubation Period, between the time of infection and the onset of disease is different for all microbes. For example with Salmonella sp (an example of food poisoning) it is only a matter of hours after you have been infected until you know you are sick. For Influenza, it may be a few days, but the frightening aspects of incubation periods are for Hepatitis and Tuberculosis. They are in the range of 6 months. That can be a long period of anxiety if one fears that they have been infected.

Why do we get sick? There are several factors such as the type of microbial invader (how virulent or pathogenic it is), the number of microbial invaders and most importantly the strength or robustness of the host (ourselves).

We all, at different stages of our lives, may or may not be more susceptible to disease. If we are undergoing drug treatments for asthma or cancer, we will have a suppressed immunity. Others that are in the immune suppressed group are diabetics, elderly people or even someone who has not slept well for several nights. The unfortunate reality is that we only find out several weeks or months later, that we have been exposed to harmful bacteria. We can not see them, so in our minds they do not exist until we get sick.

We have learned a lot in this past decade about long term microbial invasion of our bodies. Ulcers, once believed to be caused by acids, have been found in 90% of cases to be a bacteria from the Spirochaete family. Arterial sclerosis, for years was believed to be solely the deposition of fatty steroids like cholesterol, has now been found to be caused by bacterial biofilms. Even chronic fatigue in many instances has been linked to a Candida type systemic fungal infection.

Time for Preventive Action

Dentistry has perhaps the finest reputation for maintaining a serious attitude about infection control. In reality, it has had to. What other health care group is exposed to the blood and saliva of such numbers of patients? The links between the Dental Laboratory and the Dental Clinic are frequent, and the potential for transmission of disease is great. Coordination and cooperation between these groups are the keys to success in breaking the Circle of Infection.