What is gum disease?
There are multiple types of gum disease, but we will focus on two of the most common – gingivitis and chronic periodontitis.
Gingivitis is a plaque-induced disease of the gums where inflammation is present. Plaque is a material that is composed of bacteria as well as food debris, also known as calculus.
Periodontitis is also a plaque-induced disease of the gums, though it is not sufficient to initiate periodontitis (other factors must be present besides plaque in order to cause periodontitis). The main characteristic of periodontitis is the destruction of the periodontal ligaments (PDL) that surround the tooth. Periodontal ligaments connect the bone to a layer of tooth known as the cementum. Along with PDL loss, bone loss can be present with prolonged periodontitis.
Although gingivitis always precedes periodontitis, not all gingivitis will become periodontitis. In fact, periodontitis is most commonly seen in those who have plaque and are also a susceptible host. This means that other individuals have immunological factors that cause inflammation more readily, and when plaque is introduced, periodontal ligament destruction occurs due to the inflammatory response of their bodies. As the PDL is slowly removed, the gums recede. With no forces acting on the supporting alveolar bone of the teeth (the PDL exerts forces on the bone from chewing and other masticatory functions), new bone will not be laid down – leading to bone loss. As bone is lost over time, teeth will have less and less retention and will eventually become mobile.
What bacteria most commonly cause gum disease?
There are multiple bacteria that are known to cause periodontal disease, such as Porphyromonas gingivalis, Tannerella forsythia, and Aggregatibacter actinomycetemcomitans.
How do we classify periodontal disease?
There are various ways to identify gum disease. Large pocket depths, bleeping on probing, and clinical attachment loss are all signs that infection may be present. However, chronic periodontitis is clinically measured specifically by clinical attachment loss. This means periodontal ligaments have been diminished, and the gum has recessed.
Chronic periodontitis that is slight shows CAL of 1-2 mm. Moderate chronic periodontitis measures CAL of 2-4mm. Any calculation above 4mm indicates severe chronic periodontitis.
The depth of the pocket does not aid us in identifying disease. For instance, if an individual has gingivitis their gum tissue may be inflammed, causing their tissue to rise above the cementum-enamel junction (the part where the crown meets the root). When the probing depth is read, it may appear that the pocket is larger that it really is. This is why it’s important to look for signs of periodontitis such as gingival recession and bone loss.
Newman, Takei, Klokkevold, & Carranza. (2016). Clinical Periodontology (10th ed.).
(n.d.) Classification and Epidemiology of Periodontal Diseases. Dr. Dunivan. A.T. Still Missouri School of Dentistry and Oral Health
What influences gum disease such as periodontitis? What are the other gum diseases?
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