Disease Process

How does Gum Disease Progress?

The mouth contains over 300 species of bacteria- that may not sound many, but within one hour of brushing your teeth, there are over a million bacteria per mm2 of tooth surface.

Roughly speaking that is 10% of the population of the world in bacteria in your mouth just one hour after brushing, and that’s a healthy mouth! Try not to think about that next time you’re kissing someone.

So let’s look at the process of . Within minutes of brushing a pellicle forms on your tooth, you may have heard this referred to as ‘biofilm’. This is a very thin film of glyco-proteins from your saliva and is important in allowing protective elements in saliva to be absorbed onto your tooth.

Bacteria penetrate this pellicle to form the root of all evil ‘dental plaque’. Plaque can build up on filling surfaces, around braces, crowns and bridges, implants and partial dentures as well as on teeth. It cannot simply be rinsed off, so despite mouthwash claims- without brushing- plaque will stay on your teeth.

Recently, Listerine had to remove their then current advertisement, as it was deemed to be false and misleading by the ADA, claiming ‘it removes plaque’ now they have changed the word to biofilm!

Bacteria are often classified into aerobic and anaerobic; aerobic are air loving and survive best in the presence of air. Anaerobic (anti- ‘air’ obic) live best without it.

Why is this important? Well, bacteria that are aerobic build up first on your teeth and as plaque gets thicker and thicker, the bacteria at the base (nearest your tooth surface) start being starved of air and the conditions begin to favour bacteria who prefer being without air. As this happens, we often observe in the mouth, a progression from gingivitis to periodontitis and loss of attachment of the support for your teeth begins to occur.

What does this mean to you? If you go too long without brushing, or if you aren’t brushing well and plaque is left to build up and stay on your teeth- you are putting yourself more at risk of gum disease.

The amount of plaque you have in your mouth at the gum margin (where the tooth and gum meet) is proportional to the level of gingivitis you will experience. More plaque equals more severe gingivitis.

Many studies have shown that stopping brushing will bring on gingivitis and starting it again will cause it to disappear. How severe your gingivitis presents, depends on how susceptible you are and this relates to your genetics and the strength of your immune system. We call this ‘host susceptibility’ and it makes you either more, or less likely to have the problem- it may also affect the severity of the problem. You may have heard someone refer to it simply by saying’ ‘I have good or bad genes’.

There are a number of different factors that are important for chronic gingivitis to progress to periodontitis. The predominant two are:

  • The presence of plaque (the older the build up- i.e. the more anaerobic bacteria, the more risk you have). It is for this reason that most treatment is based on the regular, careful and thorough removal of our arch-enemy ‘plaque’.
  • Host susceptibility. Most of the time, there is a balance in the body between the bacteria and us. If this changes, we go from healthy to diseased. It may change, because of bacterial imbalance in the biofilm, a reduction in your immune system, or an increase in the amount of dental plaque.

If plaque is not removed, over time it will harden to form calculus or tartar (they are the same thing). Elements in your saliva (calcium and phosphate) cause this to happen, which is why calculus forms mostly where you have salivary glands- behind your front teeth on the bottom and on the cheek side of your upper first molar teeth.

If you lean your head forward and look behind your front bottom teeth, you may be able to see a yellowish build up on the tooth, around the gum margin extending up the back of the tooth – depending of course, on how good you are at cleaning your teeth and when you last saw a dentist.

Plaque always comes first and calculus can start to form after 2 weeks, although it may take many months to build up under the gum.

This is a good time to talk about the two types of calculus- calculus that forms above the gum, we call supra gingival- ‘above- gum’ and that forming below the gum on the root surface, we call sub- gingival- ‘below- gum’. Sub gingival calculus tends to be much darker in colour- brown or black and it sticks very firmly to your tooth roots.

Calculus can be detected visually under the gum and is seen by the dentist when blowing a little bit of air to reflect the gum margin, or by checking with a probe, or perhaps it is identified on X-rays as small white flecks. These flecks are often found between the molar teeth.

Why is calculus significant? Calculus is extremely hard and the longer it remains on your teeth the harder it gets and the more difficult it becomes to remove, especially once it builds up under the gum. You cannot remove it with brushing, mouthwash or flossing– it requires your dentist to use special instruments.

However, you can remove the soft dental plaque and stop it from forming in the first place. So if you haven’t had a clean for a while, it is really important you see your dentist or hygienist.

The main reason calculus is a problem is because plaque is attracted to it and sticks on its surface- we know how harmful the bacteria in plaque is and the toxins they produce can be… If you don’t know… re-read this series!

The general process for developing periodontal disease is as follows:

(i) Plaque builds up around your teeth- if it is not removed, over time it hardens to form calculus and more plaque sticks on top. Inflammation is your body’s response to bacteria and toxins; your gums become swollen and often bleed as a result.

(ii) The bone supporting your tooth is not yet affected with gingivitis. Plaque continues to build up and with the swelling of the gum, plaque begins to form slightly under the gum margin. If left, in susceptible people, the inflammation can begin destroying the bone supporting your teeth.

(iii) The gingival (gum) margin now becomes detached from the tooth and a pocket forms. Now plaque is much further under your gum and out of harm’s way…well, from the threat of your toothbrush anyway!

(iv) Here it multiplies and can harden to form (sub-gingival) calculus creating more inflammation and further bone destruction. Like termites destroying the foundation for your home, bacteria under the gum slowly eat away at the support for your teeth.

Gum recession often occurs as the disease progresses and bone continues to be lost. Eventually the teeth involved start to move and progressively loosen, until they become so loose and painful, that they fall out, or more likely, need to be removed because the prognosis is hopeless.

The disease may progress in a gradual fashion, or with bursts of attachment loss separated by periods of no change. It is very difficult to predict these times and so to give ourselves the best possible chance of slowing the progression, we need to begin gum treatment as early as possible and make sure we keep monitoring it.

A chronic gingivitis can exist for many years (indicating success on the part of our body’s defences). It doesn’t always lead to destructive periodontitis and attachment loss, but the progression could be started by a reduction in your body’s defences, or a change in the amount of bacteria in your mouth.