MI Paste Plus is a topical cream you apply directly to your teeth after brushing. It delivers calcium, phosphate, and fluoride to strengthen enamel, and the basic routine takes about five minutes. Here’s how to use it correctly, how it works, and what to know before you start.
Step-by-Step Application
The process is straightforward. Brush your teeth with your regular toothpaste first, then rinse your mouth. Squeeze a pea-sized amount of MI Paste Plus onto a clean finger and spread it across your upper teeth in an even layer, making sure to coat along the gum line. Repeat for your lower teeth. Let the paste sit for at least three minutes, then spit out the excess. Don’t rinse afterward.
If you have white spot lesions (those chalky marks that signal early decay), pay extra attention to those areas when applying. You can also use a small interproximal brush to work the paste between teeth where cavities are most likely to start.
For the best results, apply it once a day at bedtime. Using it as the last thing before sleep gives the paste hours of uninterrupted contact with your teeth. You can even leave it on overnight. A 12-month clinical trial published in the European Journal of Orthodontics had participants apply MI Paste Plus once daily at bedtime after brushing, and that single nightly application was enough to show meaningful remineralization of early cavities that had formed around orthodontic brackets.
Finger Application vs. Custom Tray
Most people use the finger method described above. It’s simple, requires no extra equipment, and works well for general use. But if your dentist has made you a custom tray (the kind used for whitening), you can squeeze MI Paste Plus into the tray and wear it instead. The tray holds the paste against your teeth more evenly and can be especially useful if you’re treating sensitivity across many teeth at once or managing widespread white spot lesions. Either method delivers the same product to the same surfaces. The tray just keeps it in place more consistently.
What MI Paste Plus Actually Does
Your tooth enamel is mostly made of calcium and phosphate. Acids from bacteria and food pull those minerals out, weakening enamel over time. MI Paste Plus reverses that process by putting calcium and phosphate back in.
The key ingredient is a milk-derived protein called CPP-ACP (marketed as Recaldent). This protein does something clever: it keeps calcium and phosphate in a dissolved, usable form so your teeth can actually absorb them. Normally, calcium and phosphate clump together and become unavailable before they can do any good. The protein prevents that clumping. When your mouth becomes slightly acidic (which happens every time you eat), the calcium and phosphate release from the protein and become available right when and where your enamel needs them most.
The “Plus” in MI Paste Plus refers to the addition of 900 ppm fluoride. That’s a meaningful amount, roughly comparable to what’s in a standard toothpaste. Fluoride and CPP-ACP work synergistically: fluoride helps form a harder, more acid-resistant mineral in the enamel, while the protein ensures there’s enough calcium and phosphate available for that mineral to form. The original MI Paste (without “Plus”) contains CPP-ACP alone but no fluoride. If you’re already using a fluoride toothpaste and want the extra remineralization boost, the Plus version gives you both in one step.
Common Uses
MI Paste Plus is most commonly recommended for:
- White spot lesions: Those white, chalky patches on teeth, often seen after braces come off. These are areas where minerals have been lost but the enamel hasn’t broken down into a full cavity yet. Consistent use can help reverse them.
- Tooth sensitivity: After professional cleaning, scaling, root planing, or teeth whitening, MI Paste Plus can reduce sensitivity by helping rebuild the mineral layer that protects nerve endings.
- High cavity risk: If you’re prone to cavities due to dry mouth, medications, or diet, nightly use adds an extra layer of protection beyond regular toothpaste.
Who Should Not Use It
MI Paste Plus is derived from milk protein (casein). If you have a milk protein allergy, do not use it. This is not about lactose intolerance, which is a digestive issue. A milk protein allergy is an immune reaction, and even topical contact with casein can trigger it. The product also contains hydroxybenzoates, and people with allergies to those compounds should avoid it as well. If you experience any allergic reaction, stop using it immediately, rinse your mouth with water, and seek medical advice.
The product should be kept out of reach of children under six. For children between six and twelve, check with a dental professional before starting use. Adults and children over twelve can follow the standard application instructions.
Storage and Shelf Life
An unopened tube of MI Paste Plus has a shelf life of 30 months. Store it at room temperature. There’s no need to refrigerate it, but avoid leaving it in extreme heat (like a car in summer). The product comes in several flavors, including strawberry, mint, and vanilla, and the formulation is the same across all of them. Once you’ve been using a tube for a while, check the expiration date printed on the packaging to make sure it’s still within its effective window.