Pathogens in dentistry: Dental assisting

Pathogens are disease-producing microorganisms and are commonly present in the dental office. As a dental assistant, you need to be aware of the types of microorganisms found in the blood, saliva, and other body fluids of patients, understand how they spread, and how to use infection control procedures to protect your patients, yourself, and the dental team by helping break the chain of infection.

Now, the three major groups of microorganisms found in the dental office are bacteria, viruses, and fungi, and each group has specific structures, modes of transmission, and reproductive processes.

Let’s start with bacteria. Bacteria are single-celled microorganisms that come in a variety of shapes, including spheres, rods, and spirals.

They can survive and reproduce on their own, when conditions are right. Most pathogenic bacteria thrive at normal body temperature, which is 98.6°F, or 37°C; and they prefer a dark and moist environment.

Some bacteria, referred to as aerobes, need oxygen to survive while anaerobes, grow without oxygen. Other bacteria, called facultative anaerobes, can grow with or without oxygen! There are also some bacteria that can survive under harsh environmental conditions by changing into spores, which are extremely difficult to destroy.

Next are viruses. Compared to bacteria, viruses are much smaller.

And, in contrast to bacteria, they’re unable to survive outside of a host cell. Instead, viruses must enter a host cell and take over its normal functions so the virus can replicate or make copies of itself. After replication, the virus is released from the host cell, which is destroyed in the process.

Last are fungi. Fungi are commonly referred to as molds and yeasts.

Now, we all have a wide variety of normal flora, or beneficial, non-pathogenic bacteria, viruses, and fungi in and on our bodies that help protect us from pathogenic microorganisms by competing with them for space and nutrients. For example, if the bacteria normally found in the mouth are destroyed by a broad-spectrum antibiotic, candidiasis, an opportunistic infection, can occur.

Alright, next let’s focus on some of the common pathogenic bacteria you’ll encounter in the dental setting and the diseases they cause. The most common bacterial diseases you’ll see in your patient are dental caries and periodontal disease.

These involve the formation of dental biofilm, or dental plaque that’s made up of communities of bacteria.

The bacteria grow and multiply as they feed upon the food and drinks we consume. In the process, they create acids that damage the teeth, and cause inflammation in the periodontal tissues.

If dental caries or periodontal disease go untreated, you may see an abscess, which is a collection of pus, or an accumulation of fluid composed of bacteria, dead cells, and tissue.

Okay, let’s switch gears and look at some common viral pathogens, including herpes simplex virus, or HSV; human immunodeficiency virus, or HIV, viral hepatitis, and COVID-19.

There are two types of herpes simplex virus.

In general, Type 1 tends to cause infections above the waist and typically affects the lips, called herpes labialis;

while Type 2 tends to cause infections below the waist and involves the genitals, called herpes genitalis. The oral lesions, commonly called cold sores or fever blisters, are highly contagious, can spread through saliva or direct contact, and pose a significant risk in dental settings.

Human immunodeficiency virus causes acquired immunodeficiency syndrome, or AIDS. HIV attacks the immune system, increasing susceptibility to opportunistic infections. Many individuals with HIV appear healthy and have no visible symptoms.