The purpose of sodium lactate in toothpaste is to increase the uptake of fluoride on the enamel surface but the mechanism it does so is unclear.
In regards to its safety, it is relatively safe to use since it is commonly used in other medical products to treat various conditions.
What is sodium lactate?
Sodium lactate is essentially the sodium salt of lactic acid. It can be produced by fermenting the sugar of corn and beets, and then using it to neutralize lactic acid.
In other words, it is very natural… Although most people are probably more familiar with its use as an IV drip.
Technical specifications:
- Description – organic sodium salt with lactate as the counterion
- Molecular formula – C3H5NaO3
Other uses:
- Ringer’s lactate solution – IV drip used to restore electrolyte balance.
- Food additive, preservative, acidity regulator, bulking agent.
- Shampoos and soaps since it is an effective humectant and moisturizer.
- Toothpastes.
What sodium lactate does in toothpaste
When sodium lactate is used as a toothpaste ingredient, it appears to enhance fluoride uptake on the enamel surface. That means it increases the tooth’s absorption of fluoride thus increasing the cavity preventative effects of the toothpaste.
Studies have shown that toothpastes with sodium lactate resulted in significantly greater surface microhardness recovery, relative erosion resistance and enamel fluoride uptake vs other toothpastes. However, the mechanism via how it accomplishes this is still unclear.
In summary, your teeth will receive an extra boost from fluoride’s protective and strengthening effects if there is lactate in the toothpaste formulation.
Benefits of fluoride on teeth
Regardless of whether sodium lactate is present, fluoride in toothpaste will strengthen, repair, and protect the enamel when applied topically.
How fluoride helps teeth:
- Strengthens enamel. Fluoride ions will replace the hydroxyl ions, thus converting the tooth mineral hydroxyapatite to fluorapatite. This improved mineral is larger, more stable, and more acid resistant. In other words, it is less likely to succumb to cavities.
- Repairs weakened enamel. Demineralized enamel from acidic attacks can be repaired with fluoride, which pulls in other tooth minerals such as calcium and phosphate. The combination of all 3 will help remineralize the damaged tooth.
- Protects enamel from acid dissolution. Fluoride can form a calcium-fluoride layer over the teeth which acts as a sacrificial barrier. When bacteria attacks the tooth with acid, this layer will dissolve first instead of the enamel.
What the addition of lactate does in the toothpaste is to exponentiate the existing benefits from fluoride, thus making it more efficacious.
Side effects
There is only one research study with sodium lactate in toothpaste and there were no adverse effects reported. It is still a novel toothpaste ingredient and not very many dentifrices even have it in their formulation.
As of the moment, only a few of the Sensodyne toothpastes even contain it.
Nonetheless, it should be relatively safe to use since it is a major ingredient in IV drips used in hospitals. Patients who are dehydrated or present with fluid loss often receive this to replenish their electrolytes and fluids.
Potential adverse effects
There may not have been any reported side effects in toothpaste use but adverse effects have been reported when it has been used elsewhere.
| Type of reaction | Signs & Symptoms |
|---|---|
| Allergic reaction | Rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; Wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; Unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat. |
| Fluid and electrolyte problems | Mood changes, confusion, muscle pain or weakness Fast or abnormal heartbeat, severe dizziness or passing out, Increased thirst, seizures, feeling very tired or weak, decreased appetite Unable to pass urine or change in the amount of urine produced, dry mouth, dry eyes, or severe upset stomach or throwing up. |
| Others | Shortness of breath Big weight gain Swelling in the arms or legs. |
To reiterate, the side effects noted above can be potentially observed when sodium lactate is used as an IV drip or other form of medication. None of it has been reported or observed when used in oral care products.
As of the moment, it should be relatively safe to be used in toothpaste since you’re not ingesting or swallowing any of it. All toothpaste should be spit back out so that minimizes the absorption of it into your system.
If anything, it is probably safer as a toothpaste ingredient than when used elsewhere.
Takeaway
Sodium lactate is a novel toothpaste ingredient since it was only fairly recently when it began to be added to some of the sensodyne formulations. As a matter of fact, there are only a handful of the sensodyne toothpastes even with it.
That means there isn’t much information in regards to it.
However, what we do know is that it seems to help increase the fluoride uptake on the enamel surfaces of teeth. That in turn helps exponentiate the benefits of fluoride on teeth thus making the fluoridated toothpastes more efficacious.
Aside from that, we don’t actually know how it does what it does.