The role that calcium plays in teeth remineralization and demineralization mechanics cannot be understated because teeth are made of it.
In other words, its presence is a factor that affects cavity formation and also its subsequent repair from tooth decay.
Table of Contents:
Teeth are made of calcium
Calcium is a quintessential mineral for maintaining healthy teeth because your tooth is literally made of it in the form of hydroxyapatite.
Hydroxyapatite [Ca₁₀(PO₄)₆(OH)₂] is the predominant mineral form for teeth and it consists of calciums, phosphates, and hydroxyl groups. Alternatively, it is also commonly referred to as calcium apatite.
Facts:
Enamel inorganic portion is 87% of volume and 95% of its weight.
The inorganic part consists of 89% calcium hydroxyapatite, 4% calcium carbonate, 2% calcium fluoride, and 1.5% magnesium phosphate,
Pure hydroxyapatite is composed of 57% phosphorus, 40% calcium and 2% hydroxyl ions.
In summary, calcium is very important for our dentition because without it, we wouldn't have teeth. This is also why calcium along with phosphorus are considered tooth minerals.
Calcium in Remineralization/Demineralization
Teeth will shift between states of demineralization (cavity formation) and remineralization (enamel repair).
Demineralization. Loss of tooth minerals, calcium & phosphate.
Remineralization. Gain of tooth minerals, calcium & phosphate.
Demineralization mechanics
During tooth decay formation or while under acidic attacks, the enamel will begin to demineralize. That is characterized by a loss of the minerals, calcium and phosphate from the surfaces of teeth.
Consequently, if the tooth loses enough calcium, the overall structural integrity will become compromised and collapse under its own weight. The end result is a cavitation/hole or otherwise known as a "cavity."
Alternate explanation: Acidic attacks cause the tooth to start dissolving. The tooth mineral hydroxyapatite breaks up into its individual components, calcium and phosphate, which get released back into the mouth.
Remineralization mechanics
Remineralization of demineralized tooth surfaces begins when the acidic oral environment gets buffered back to neutral. This is characterized by regaining the lost minerals calcium and phosphate back into the surfaces of the teeth.
Caveat: Remineralization can only proceed if there is excess calcium in the saliva. In other words, if you don't have enough calcium in your saliva, there will be nothing to remineralize. Basically, if you don't have the building blocks to repair the enamel, it will not be able to repair itself.
Calcium is the limiting factor for remineralization
Studies have shown that it is calcium (Ca) and not phosphate (PO4), is often the limiting factor in tooth remineralization. In vivo, our mouth soften have Ca:PO4 ratio of 0.3 which makes it the limiting mineral.
The ideal ratio is 1.6 which means our mouths should have a lot more calcium than phosphate. However, in most instances, the reverse is true where there is more phosphate than calcium. That means that the oral environment is not optimized to restore damaged enamel.
Now that brings us to our next topic of how to acquire/obtain sufficient calcium so that we can remineralize carious lesions effectively.
How to get calcium for teeth
The two most common ways to get calcium for teeth to remineralize would be from our diet and also from using toothpastes.
Diet
Ideally, we should all be getting our RDA (recommended daily allowance) of calcium through our diet alone. However, a lot of adults fail to meet the RDA standards which is how people end up at risk for osteoporosis.
Dairy products - cheese, milk and yogurt.
Dark green leafy vegetables - broccoli and kale.
Fish with edible soft bones - sardines and canned salmon
Calcium-fortified foods and beverages - cereal.
Supplements as an alternativeTeeth made of calcium
If you're not able to meet your daily calcium requirements from consuming whole foods, an alternative would be taking supplements.
Forms of calcium supplements:
Calcium carbonate (40% elemental Ca)
Calcium citrate (21% elemental Ca)
Calcium gluconate (9% elemental Ca)
Calcium lactate (13% elemental Ca)
Calcium hydroxyapatite
Yes, you read that last one correctly, there are supplements in the form of hydroxyapatite. That is precisely the same mineral found in your teeth and bones!
Note: Since hydroxyapatite is often taken as a supplement, that also makes hydroxyapatite-based toothpastes very safe to use.
Toothpaste
A lot of toothpastes contain calcium in one form or another as an ingredient in its formulation. The purpose is to ensure an excess supply of Ca to fight tooth decay.
Forms of Ca found in toothpastes:
Hydroxyapatite toothpastes. Often marketed as a fluoride alternative dentifrice, this type of toothpaste is as close to a synthetic enamel paste as you can possible get.
Calcium carbonate. A common toothpaste ingredient that also acts as a mild whitening abrasive. If you don't know what this is, TUMS is made of it.
Tricalcium phosphate. A stabilized functional version of calcium phosphate that does not interact with fluoride toothpastes. This is by Rx only.
CCP-ACP based toothpastes. Casein phosphopeptide-amorphous calcium phosphate is a stabilized version of calcium which maximizes remineralization capabilities.
The nano-hydroxyapatite toothpastes have been incredibly trendy but they also command a price premium oftening priced at $10-12 a tube. But if you want a cavity prevention toothpaste that is fluoride free, this is your only option.
Calcium may interfere with fluoride
One study demonstrated that toothpastes with sodium monofluorophosphate and calcium carbonate can help prevent/reduce cavities.
However, other forms of fluoride such as sodium fluoride (NaF) and stannous fluoride (SnF2) may have reduced anti-caries efficacy when formulated with calcium carbonate.
Explanation: Poorly soluble forms of calcium will interact with fluoride to form CaF (calcium fluoride) thus reducing its bioavailability in the mouth. That means the amount of Ca and F that can be adsorbed by your teeth will be reduced.
Exception: Toothpastes with calcium in the form of casein phosphopeptide amorphous calcium phosphate (CPP-ACP) does not suffer from reduced bioavailability. It maintained a near 100% bioavailability of fluoride and calcium.
As of the moment, the CCP-ACP toothpastes are by prescription only meaning that you can only obtain it through your dentist. You can't purchase it without a dental license.
Is calcium good for teeth?
Yes, having enough calcium in our diet ensures that we build and maintain strong healthy teeth. Without it, our teeth will become weakened via demineralization or decalcification. Both of which results in a loss of calcium from the dentition.
Overall, it is a necessary mineral if we want to strengthen our teeth. If you remember while growing up, the old adage about drinking enough milk to help grow strong bones and teeth. That still holds true to this very day.
Takeaway
Calcium is good for our teeth because it plays an important role in keeping them healthy. Lack of it will result in demineralization and decalcification of the enamel.
During demineralization, teeth lose calcium.
However, teeth require calcium during remineralization to repair itself.
Calcium is also the limiting mineral during enamel repair.
In summary, it is of utmost importance to consume enough of it in our diet so that we can effectively fight off tooth decay. It also doesn't hurt to use a toothpaste which have it in its formulation because that can only help. Last but not least, don't forget to get your dental check up every 6 months to make sure you're on track!