Mouth guards are effective at protecting teeth against grinding, clenching and has numerous other benefits. However, some people have experienced side effects such as tooth pain or increased saliva production. Some night guard users claim that a mouth guard hurts gums or causes too much discomfort and for these reasons they stopped wearing it. A properly fitting mouth guard should not hurt your gums.

If you are wearing a custom night guard, then your dentist or the dental lab that made your night guard will have to adjust it for you. The people who typically experience these issues are using a store bought boil and bite mouth guard. As such, the advice in this article is aimed primarily at this audience.

Possible Reasons Why Your Mouth Guard Hurts Gums

Here are the top reasons why your mouth guard hurts gums and how you can approach each problem.

You Are Not Used to Wearing a Night Guard

It is common for the first week or two of wearing a night guard to be uncomfortable. Even if there is no pain, you are not used to sleeping with a piece of plastic in your mouth. That feeling of waking up with sore gums, teeth, or any other annoyances that you don’t normally feel will go away as your mouth acclimates to the guard.

It may seem like you are simply trading one set of problems for another, however these issues are less severe and will disappear on their own. As long as you stop grinding or clenching your teeth at night, just proceed as usual and within a couple of weeks you will wake up free from pain.

Low Material Quality

Your boil and bite mouth guard might be old, or made from low quality material. Modern night guards are made of tough acrylic on the outside, but the inside should be a highly moldable, gel-like plastic. Aside from the initial discomfort it may bring you, you should otherwise be pain free. If you still experience pain after a week or two, then the quality of your night guard may be the reason, or you may have to reboil your mouth guard.

Night Guard not Molded Properly

One downside of a boil and bite mouth guard is that first time users can mistakenly make a poor mold on their first attempt. After boiling, the instructions may ask you to bite down on the guard in a certain way. For instance, you may be asked to bite with your jaw sticking forwards more, or to flip the guard upside down before making an impression of your teeth on the soft plastic.

Furthermore, the user may not know how hard they need to bite, or they may accidentally bite it at an angle. The end result is a night guard mold that fits awkwardly on your teeth, and this may irritate your gums as well. Sometimes, excess plastic that have been displaced where you bit down will form jagged edges that stab the inside of your mouth. These will need to be trimmed. If there is enough plastic left, you may be able to reboil the mouth guard once more to make a better mold on your teeth.

Sensitive Gums Caused by Gum Disease

Your gums may feel pain when wearing a night guard due to gum disease such as gingivitis or periodontitis. Make sure you floss regularly with dental floss, a water flosser, or both to remove plaque as part of your daily oral care regimen. You should also incorporate mouthwash because they can eliminate the bacteria in your mouth that causes gingivitis.


There are many reasons why a mouth guard hurts gums, and not all of it is the product’s fault. You might simply have to go through an adjustment period before the pain dissipates. Perhaps the quality of the night guard is low, in which case you may decide to get a custom night guard instead. For boil and bite mouth guards, it is common for a user to make a bad mold and reboiling it and trimming any excess plastic might be necessary.

If you do not have a good oral care regimen or do not go to dental check-ups every six months, you may be suffering from a gum disease that is making your gums sensitive. Be sure to stay on top of your dental hygiene to prevent discomfort beyond experiencing gum pain from wearing mouth guards.