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Factors that cause tooth decay- your definitive guide

Today Time Dental‘s series on tooth decay continues with the cause of tooth decay. Last week we looked out the signs and symptoms of tooth decay and what it can lead to.

For decay to occur there needs to be three main factors: decay-causing bacteria, fermentable carbohydrates, and time.

There are other factors that can contribute to decay which we will shall discuss but it makes sense that the key to preventing tooth decay is to deal with the three main factors that cause it.

The bacteria that causes tooth decay


The decay-causing bacteria are specific types that produce acid from carbohydrates that we eat such as glucose, sucrose and fructose. We have already discussed how the mouth is in a constant tug-of-war all day long between remineralization and demineralization, so the decay will occur when the balance is tipped by the acid producing bacteria resulting in more demineralization. The area that the decay occurs on the tooth is where the plaque bacteria is left behind. The most common areas being in between the teeth and in the pits and fissures of your back teeth as these are the most plaque-retentive sites.

Carbohydrates such as glucose, fructose and sucrose in foods that we eat are converted into acids such as lactic acid by a process called fermentation. If this acid is left in contact with the tooth it can dissolve the mineral content of the tooth resulting in the “white spot lesions” indicating the early stages of decay.

The frequency of exposure of the teeth to the acid produced by the bacteria affects whether tooth decay is likely to start. So after eating meals or snacks the bacteria in the mouth will use the sugar to produce the acid which decreases the pH level in the mouth making the teeth at risk of tooth decay. The buffering effect of the saliva helps to neutralize the acid but only over a period of 30 -60 minutes. You can understand  that the resulting tooth decay is dependent on the frequency of acid attack produced by the bacteria.

Other factors such as reduced saliva rate which affects the buffering action to counter the acid attack can affect the likelihood of decay. Certain medical conditions and also medication can affect the saliva rate.

Next time we’ll be looking at the preventative measures to stop tooth decay happening.



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