Most mouth sores caused by Invisalign heal within 10 to 14 days once the source of irritation is addressed. The sores are almost always friction injuries from the edges of the aligner rubbing against your cheeks, gums, or tongue. The good news: you can speed up healing and reduce pain with a few targeted steps at home.
Why Invisalign Causes Mouth Sores
The edges of clear aligners can have rough or sharp spots that dig into soft tissue, especially during the first few days of a new tray. Each time you switch to a new set, the fit changes slightly, and new pressure points can develop. Aligners also have attachments (the small bumps bonded to your teeth) that create additional friction zones on the inside of your lips and cheeks.
Beyond mechanical irritation, aligners aren’t perfectly smooth at a microscopic level. They contain grooves, ridges, and microcracks that encourage bacterial buildup. If you’re not cleaning your trays regularly, that bacterial film sits against an open sore for 20-plus hours a day, which can slow healing and raise the risk of gum inflammation.
Smooth the Tray Edge That’s Causing the Problem
Before you focus on healing the sore itself, stop it from getting re-injured every time you put your trays back in. Remove the aligner and run your finger along the edges to find the rough spot. Then use a fine-grit nail file (an emery board works perfectly) to gently smooth the area. File just enough to remove the roughness, and rinse the tray thoroughly before reinserting it.
If filing isn’t enough, or the irritation comes from a broader area rather than a single sharp edge, orthodontic wax is your next tool. Make sure your aligners are clean and properly seated on your teeth. Pinch off a pea-sized piece of wax, roll it between your thumb and index finger to soften it, then press it over the trouble spot. Use your fingertip to mold it around the area so it stays in place. The wax creates a smooth barrier between the plastic and your tissue, giving the sore room to heal while you continue wearing the tray.
Rinse With Salt Water
A warm saltwater rinse is one of the simplest and most effective ways to promote healing. Research on gingival wound healing found that a concentration of about one teaspoon of salt (5 grams) dissolved in one cup of water (250 ml) supports tissue repair. Rinse for about two minutes, three times a day. The salt draws fluid from swollen tissue, reduces bacteria in the area, and creates a better environment for new cells to close the wound.
Use Over-the-Counter Pain Relief
If the sore is making it painful to eat or wear your trays, topical products can help. Numbing gels containing benzocaine (sold under names like Orajel and Anbesol) work quickly to dull pain when applied directly to the sore. For a more antiseptic approach, hydrogen peroxide rinses like Peroxyl help clean the wound and can speed healing. Apply these products as soon as a sore appears for the best results.
You can also use both approaches. Apply the numbing gel before meals or before reinserting your trays, and use the antiseptic rinse at other times during the day. Just avoid using the hydrogen peroxide rinse more than directed on the label, since overuse can irritate healthy tissue.
Keep Your Aligners Clean
A dirty tray pressing against an open sore is a recipe for slower healing. Biofilm builds up on aligners quickly, and that bacterial layer increases the risk of both cavities and gum irritation. The most effective cleaning approach combines mechanical and chemical methods: brush the trays with a soft toothbrush, then soak them in a cleaning solution. Research has shown that brushing combined with a chemical cleaner outperforms brushing alone at removing bacterial buildup. Rinse them before putting them back in your mouth, especially after eating.
Avoid Foods That Delay Healing
What you eat while a sore is healing matters more than you might expect. Three categories of food are especially problematic:
- Acidic foods cause stinging and can actively delay healing. This includes citrus fruits, tomatoes, pineapple, berries, vinegar, coffee, and fruit juice.
- Spicy foods containing capsaicin irritate open sores. Skip hot sauce, salsa, curry, and anything with chili powder or crushed red pepper.
- Crunchy or rough foods can physically scrape the sore and reopen it. Avoid granola, pretzels, chips, popcorn, and crusty bread until the sore has closed.
Stick to soft, cool, or room-temperature foods while you’re healing. Hot food can also intensify pain at the sore site.
How Long Healing Takes
Friction sores inside the mouth generally heal in about 10 days once the cause of the injury is removed. If the irritation continues (because a sharp edge hasn’t been filed or wax hasn’t been applied), the sore can linger for weeks. The first three days after a sore forms are often the least painful, with discomfort peaking in the middle of the healing window before gradually fading. If you’ve addressed the source of the friction and are keeping the area clean, most sores resolve within two weeks.
When a Sore Isn’t Just Friction
Occasionally, what seems like a normal aligner sore is actually something else. An allergic reaction to the aligner material goes beyond typical soreness. It usually involves itching, burning, or swelling on soft tissues like the tongue, lips, or gums. Some people also develop a skin rash around the mouth, excessive saliva production, or a sore throat. If you notice these symptoms, remove the aligners and contact your orthodontist.
You should also pay attention to sores that don’t follow a normal healing pattern. Sores lasting longer than three weeks, new sores appearing before old ones have healed, unusually large ulcers, sores that are completely painless, or sores accompanied by fever all warrant a call to your provider. Pain that doesn’t respond to any of the topical treatments mentioned above is another signal that something beyond simple friction may be going on.