The toothpaste ingredient, tricalcium phosphate is primarily used as a tooth remineralization agent although it does have a couple of additional benefits that you may not be aware of. As for its safety, you can practically eat it without it being harmful. I believe that should give you a good idea for how "dangerous" it can be.
Tricalcium phosphate in toothpaste overview:
Description: White amorphous powder often taken as a bone supplement.
Benefits: Tooth remineralization, acid neutralization, teeth desensitization.
Antagonists: No adverse interactions with other ingredients.
Side effects: None observed in practice.
Safety: Safe for ingestion. No observed risks.
Availability: Prescription only.
What is tricalcium phosphate in toothpaste?
Tricalcium phosphate (TCP) is a calcium salt of phosphoric acid, it is essentially made of calcium and phosphate which are the bone/teeth minerals. Its appearance is that of a white amorphous powder.
If that description sounds too foreign for you, TCP is commonly found in bone/calcium supplements, antacids, and also in prescription toothpaste.
Rx toothpastes with TCP:
3M Clinpro 5000
Colgate Prevident 5000
In regards to toothpaste formulations, tricalcium phosphate is typically referred to as a stabilized functional version of calcium phosphate. The reason is because when it is in this form, it does not interact with fluoride in the toothpaste.
Benefits in toothpaste
The primary purpose of tricalcium phosphate in toothpaste is as a remineralization agent but it can also be used to neutralize oral acids and desensitize teeth. Overall, you can think of it as a protective ingredient that is beneficial for your teeth in many ways. It is better to have it than to not have it.
Remineralize teeth
Tricalcium phosphate can help remineralize teeth because it can directly supply calcium and phosphate to demineralized enamel. This will essentially repair minor enamel defects such as incipient carious lesions.
Remineralization and demineralization dynamics:
Demineralization is when the tooth loses minerals (calcium/phosphate).
Remineralization is when the tooth regains the lost minerals.
What makes TCP so advantageous is that it packages the calcium and phosphate into a functionalized form that is stabilized. It will not interact with other toothpaste ingredients (fluoride) before it reaches the tooth.
Important points regarding its efficacy
Fluoride is still the most important remineralizing agent but tricalcium phosphate can certainly help with the process. This was demonstrated in a study that used a combination of fluoride and TCP.
The diagram below shows that fluoride with TCP was the most effective at remineralizing. However, fluoride alone was still much more effective than TCP without fluoride.
Remineralization effectiveness of toothpastes:
Fluoride + TCP.
Fluoride without TCP.
TCP without fluoride.
No TCP and no fluoride.
Last but not least, TCP is also not as effective as hydroxyapatite when it comes to remineralization. Studies demonstrated that TCP was less effective than hydroxyapatite as well as CCP-ACP in repairing enamel.
In conclusion, while tricalcium phosphate can remineralize teeth, it is less effective than both fluoride and hydroxyapatite. Although when you combine it with those two ingredients, it can exponentiate their effects.
 Neutralize acids
Aside from remineralizing teeth, it can also help prevent or reduce the risk of cavities by neutralizing oral acids. Tricalcium phosphate can act as a buffering agent by rebalancing the pH back to neutral.
This is important because teeth become decayed and eroded only when the oral pH drops into the acidic range which results in demineralization.
However, when the pH rises back to neutral, the remineralization process begins. It is able to do this because the mouth naturally has a phosphate buffering system. As you can see in the name, TCP literally contains phosphates!
Desensitize teeth
While not the most prominent effect nor is it actively marketed, TCP can in fact desensitize teeth by occluding open dentinal tubules. That means it works the same way in desensitizing teeth as stannous fluoride and hydroxyapatite.
Studies have shown that it can occlude the dentinal tubules but it isn't as effective as hydroxyapatite or CCP-ACP in doing so. Basically it is not the most effective desensitizer but it can help alleviate some of the discomfort.
Antagonists
As of this moment, there are no known antagonistic toothpaste ingredients that interact with tricalcium phosphate. As a matter of fact, TCP was developed because other forms of calcium such as calcium carbonate, would negatively impact fluoride in toothpaste.
Studies have shown that calcium carbonate would bind with sodium fluoride and thus reduce the bioavailability of fluoride. The calcium and fluoride would interact with each other and form calcium fluoride instead of interacting with the tooth!
The advantage in using TCP is that it does NOT interact with fluoride in that way, which is why it is referred to as a functional version of calcium. This results in a greater bioavailability of fluoride that can be used to repair the enamel.
Side effects
Toothpaste is meant to be used topically and then expectorated afterwards so there should be very little adverse effects if any at all.
Although if you do miraculously ingest a lot of it, the typical adverse reactions would be similar to excessive calcium in the blood (hypercalcemia).
Digestive symptoms - nausea, vomiting, poor appetite, or constipation.
Nephrotic symptoms - increased thirst or more frequent urination.
Muscle weakness and twitches.
Tiredness, fatigue, and confusion.
According to Penn Medicine, hypercalcemia can cause bones to become more fragile and break more easily but that is not applicable for toothpaste calcium. Hypercalcemia from toothpaste ingestion does not have the same underlying etiology so you need not be concerned.
Safety
Overall, tricalcium phosphate is a relatively safe ingredient to be used in toothpaste because it is technically a bone/calcium supplement.
Two common uses for TCP:
Bone/calcium supplement. Yes, this is sold in a tablet/pill form to be taken as a supplement. Calcium supplements can come in many other forms as well such as calcium hydroxyapatite.
Antacid for heartburn. Pepto Kids is a tricalcium phosphate antacid that is used to relieve heartburn or indigestion for children.
The point that I'm trying to make is that it is safe enough to eat so even if you swallow some from your toothpaste, it will not harm you.
In case you needed additional reassurance, studies have shown that no adverse effects have been observed when TCP is absorbed. It poses little risk because osteoclasts and macrophages will break it down to be properly absorbed.
Where can I buy it?
Unfortunately you can't purchase toothpastes with tricalcium phosphate over the counter. It is available by prescription only, meaning you need to have to prescribed for you by your dentist.
As proof, here is the product label for clinpro 5000 which clearly states it is by Rx.
If you're interested in using this product, you should schedule a consultation with your dentist to discuss if you are a candidate for it.
Verdict
In my opinion, I think tricalcium phosphate is a fabulous toothpaste ingredient for preventative dentistry because of its remineralization, oral buffering, and desensitizing capabilities.
Who would benefit from using this type of toothpaste:
High risk for cavities.
White spot lesions.
After braces removal.
It is an ingredient that I would consider using in my own personal toothpaste formulation. I can't find any reason not to use it.
Reasons I would include it in toothpaste:
Calcium is the limiting factor for remineralization.
CCP-ACP is more effective than TCPÂ but it's derived from dairy so there may be allergic interactions for some people.
Once again, it is a candidate to be included in my future remineralization toothpaste. Although one question I do have is why it is only in prescription toothpastes...
