MI Paste Plus is a prescription topical paste used to strengthen tooth enamel, reduce sensitivity, and prevent cavities. It combines a milk-derived protein called RECALDENT with 900 ppm of fluoride to deliver calcium, phosphate, and fluoride directly to the tooth surface. Dentists most commonly recommend it for patients at high risk of cavities, those with braces, and people dealing with dry mouth.
How MI Paste Plus Works
The active ingredient in MI Paste Plus is a compound derived from milk casein protein. It carries calcium and phosphate ions and releases them onto the tooth surface, essentially resupplying the building blocks your enamel needs to repair itself. This process is called remineralization, and it’s the same thing your saliva does naturally, just concentrated and applied where it’s needed most.
What makes the “Plus” version different from regular MI Paste is the addition of 900 ppm fluoride. When fluoride combines with the calcium and phosphate on the tooth surface, it creates a mineral layer called fluorapatite, which is more resistant to acid than the original enamel. This makes MI Paste Plus particularly effective for people who face ongoing acid exposure from sugary diets, acidic drinks, or reduced saliva flow.
Cavity Prevention for High-Risk Patients
MI Paste Plus is primarily used to prevent cavities in people whose teeth are under more stress than average. That includes patients with a history of frequent decay, those undergoing radiation therapy near the mouth, and anyone whose saliva production has dropped due to medication or medical conditions. A clinical trial comparing MI Paste Plus to a control group over six months found a significant reduction in early cavity scores among the MI Paste Plus users. The mean score of early lesions dropped by 2.9 units after two months and 3.85 units after four months, showing that benefits build over time with consistent use.
In the same study, MI Paste Plus performed slightly better than professional fluoride varnish applications, though the difference between the two wasn’t statistically significant. Both were clearly better than no treatment. This suggests MI Paste Plus is a strong at-home option that can match or approach the protection of in-office fluoride treatments.
White Spot Lesions After Braces
One of the most common uses for MI Paste Plus is treating or preventing white spot lesions, the chalky white marks that often appear on teeth during or after orthodontic treatment. These spots are areas where minerals have leached out of the enamel, typically around the edges of brackets where plaque accumulates. They’re not full cavities yet, but they’re the first visible stage of decay.
For orthodontic patients, dentists often prescribe MI Paste Plus as part of a daily regimen during and after braces. Clinical protocols for treating white spot lesions typically run about eight weeks, with follow-up assessments at 3, 6, 12, and 18 months to track whether the spots fade or disappear. Results vary. Some lesions remineralize enough to blend back into the surrounding enamel, while deeper or older spots may improve but not vanish completely. Starting treatment soon after braces come off gives the best chance of reversal, since newer lesions respond more readily to remineralization.
Tooth Sensitivity Relief
MI Paste Plus can help reduce dentin hypersensitivity, the sharp pain you feel when hot, cold, or sweet foods hit exposed areas of your teeth. This happens when the protective enamel thins or the gum line recedes, leaving tiny channels in the tooth’s inner layer open to stimulation. The calcium and phosphate in MI Paste Plus help plug those channels by depositing minerals on the exposed surface. The paste also adheres well to tooth surfaces and soft tissue, which allows it to stay in contact with sensitive areas longer than a regular rinse or toothpaste would.
Dry Mouth Support
People with chronic dry mouth (xerostomia) face a higher risk of decay because saliva is the mouth’s primary defense against acid and bacteria. Without enough of it, teeth lose minerals faster than they can be replaced. MI Paste Plus helps fill that gap by delivering minerals directly, bypassing the need for saliva to do the job. The University of Iowa’s head and neck protocols describe it as “probably the best product we have to provide oral comfort” for dry mouth patients, noting that it soothes dry oral tissue in addition to rebuilding tooth structure. Applying it at bedtime is especially useful since saliva flow drops even further during sleep.
How to Apply MI Paste Plus
Start by brushing your teeth thoroughly with your regular toothpaste (or a prescribed high-fluoride toothpaste if your dentist has recommended one) and rinsing with water. Then apply a pea-sized amount of MI Paste Plus along the gum line of your upper and lower teeth using a clean finger, toothbrush, or cotton swab. Pay extra attention to areas with visible white spots or known sensitivity.
Leave the paste on your teeth for at least two to three minutes. You can spit out excess afterward, but don’t rinse. Don’t eat or drink for 30 minutes after application. Many dentists recommend using it once daily at bedtime and leaving it on overnight for maximum contact time. Your dentist may adjust the frequency based on your specific situation.
Who Should Not Use MI Paste Plus
MI Paste Plus is made from milk casein protein, which means it is not safe for anyone with a milk protein allergy. This is a firm contraindication, not a precaution. The FDA has received adverse event reports related to allergic reactions in sensitive individuals. The product also contains benzoate preservatives, so people with a known sensitivity to benzoates should avoid it as well. If you’re unsure whether you have either allergy, check with your dentist or allergist before starting use.