Do teeth really dissolve if left in the soft drinks?


We have heard that if human tooth is dipped overnight in soft drinks such as Coke and Pepsi, the tooth will dissolve overnight. Is this really true? Well the good news is that even if the tooth is dipped in the same soft drinks for months, it will not dissolve completely. Before we look into this phenomena, let’s briefly overview what happens inside our mouth upon exposure to soft drinks?

Dental erosion or chemical induced mineral loss from tooth structure occurs at pH below 5.5 (pH is a measure of acidity/alkalinity of any substance. Generally lesser the pH, the more pronounced mineral loss will be expected). Inside the mouth, the mineral loss from the tooth has been shown to be pH dependant. Low pH solutions have more potential to cause mineral loss leading to softening of the tooth surface as well as softening of dental fillings. Once the process of mineral loss starts inside the mouth, the bacteria in mouth may further accelerate this process. In addition, the saliva flow decreases which means that the low pH will be maintained inside the mouth for longer duration, hence facilitating more mineral loss.

Does that mean all foods and drinks with pH less than 5.5 will cause mineral loss?

The answer is No.

The classical example is yogurt which has pH less than 4.0. Yogurt does not cause mineral loss from tooth because it contains high levels of Calcium and Phosphate (supersaturation) rather the teeth uptake Calcium from Yogurt.

Now let’s look at the tooth dipped in soft drinks solution. At the start, the soft drinks or solutions having less than 5.5 pH will cause mineral loss from tooth. The tooth will start to leach out Calcium and other minerals into the solution till the solution reaches a point where Calcium and other minerals reach an equilibrium level. At this point, no further loss of Calcium or other minerals will occur. The only way the tooth can now loose Calcium will be if part of the solution is removed, hence depleting Calcium concentration which will cause leaching out of Calcium from tooth.  

To conclude the soft drinks and acidic drinks are more harmful when ingested as they have more potential to cause mineral loss from teeth as well as dental fillings. Rinsing mouth with water immediately after soft drinks helps clear the low pH. Similarly avoiding brushing your teeth 30 minutes to an hour after soft drink ingestion also prevents mechanical loss of Calcium from tooth.

Muhammad Wasif Haq, Mehwish Batool, Syed Hammad Ahsan, Muneeb Ahmed Lone and Tanweer ul Islam(2012). Dental erosion; influencing factors & pH analysis. Canadian Journal of Applied Sciences. 2012; 2(1): 222-32

Written by Muhammad Wasif Haq (2019)
Perth, Australia
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