Dentures need to stay moist whenever they’re out of your mouth. Most denture materials hold their shape by retaining water, so the simplest rule is this: if they’re not on your gums, they should be submerged in liquid. Beyond that basic principle, the type of liquid you use, the temperature, and your cleaning routine before storage all affect how well your dentures hold up over time.
Why Dentures Can’t Dry Out
Dentures are made from acrylic resin, a material that absorbs and releases moisture. When left in open air, the acrylic loses water and undergoes small dimensional changes. Research measuring denture width after just eight hours of drying found statistically significant increases in the distance between the back molars. While these shifts were small enough in a single episode that researchers considered them not clinically significant on their own, repeated cycles of drying and rehydrating compound the problem. Over time, a denture that regularly dries out can develop a subtly different shape, leading to a looser or more uncomfortable fit.
Keeping dentures submerged prevents this cycle entirely. The acrylic stays saturated, the shape stays stable, and the denture continues fitting the way it was designed to.
What to Soak Them In
Plain water works as a baseline. It keeps the acrylic moist and prevents warping. But if you want to go a step further, adding a denture-cleaning tablet to the water makes a meaningful difference in hygiene. A randomized clinical trial found that overnight storage in water with a cleaning tablet significantly reduced total bacterial counts compared to storage in plain water or dry storage. The tablets release a fizzing solution that breaks down the sticky film of bacteria that builds up on denture surfaces throughout the day.
This matters because that bacterial film isn’t just cosmetic. When it’s left to accumulate, it can contribute to a condition called denture stomatitis, a persistent redness and irritation of the tissue under the denture. Soaking in a cleaning solution overnight helps keep that biofilm under control, especially if your brushing routine isn’t perfect every single day.
If you use a cleaning tablet, follow the instructions on the package for how long to soak. Most dissolve in a few minutes but are designed for an overnight soak. Rinse your dentures thoroughly with clean water before putting them back in your mouth the next morning, since the soaking solution isn’t meant to be ingested.
Water Temperature Matters
Always use cool or lukewarm water. Hot water, and especially boiling water, can warp the acrylic permanently. Once a denture warps from heat exposure, the fit changes in ways that can’t be reversed at home. This applies to both cleaning and soaking. Even running dentures under very hot tap water can cause enough heat transfer to distort the material. Room-temperature or slightly warm water is safe and effective.
Clean Before You Store
Soaking alone doesn’t replace brushing. Before placing your dentures in their overnight container, brush them with a soft-bristled brush to remove food particles and loose debris. You can use a mild dish soap or a denture-specific paste. Avoid regular toothpaste, which often contains abrasives that can scratch the denture surface. Those tiny scratches create grooves where bacteria settle in and become harder to remove.
Rinse the dentures under running water after brushing, then place them in your soaking container. If you’re using a cleaning tablet, drop it into the water after the dentures are submerged. This sequence, brush, rinse, soak, gives you the best combination of mechanical cleaning and chemical disinfection overnight.
Choosing a Storage Container
Any clean container deep enough to fully submerge your dentures will work. Many people use the plastic cases that come with denture-cleaning products, but a clean cup or small bowl does the same job. The key is that every surface of the denture stays underwater. A denture sitting half-submerged can dry out and change shape on the exposed side while the submerged side stays stable, creating an uneven fit.
Change the water or solution fresh each night. Reusing the same liquid breeds bacteria rather than eliminating them. Give the container itself a quick rinse or wash every few days to prevent buildup on its walls.
Storing Dentures You Won’t Wear for a While
If you have a spare set or won’t be wearing your dentures for days or weeks, the same rule applies: keep them submerged. The American Dental Association recommends storing dentures in clean water or a denture-cleaning solution regardless of how long they’ll be out of your mouth. Change the water every day or two to keep it fresh.
Wrapping dentures in a damp towel and placing them in a sealed bag might seem like a reasonable shortcut, but the towel dries out faster than you’d expect, and within hours the dentures are essentially in dry storage. Full submersion in a container of water is more reliable and requires less attention.
What to Avoid
- Hot or boiling water. Warps the acrylic and permanently alters the fit.
- Bleach or harsh household cleaners. These can weaken the acrylic, discolor it, or corrode any metal components like clasps on partial dentures.
- Dry storage on a countertop or nightstand. Even one night of air drying starts the dehydration process.
- Regular toothpaste. Too abrasive for denture surfaces, creating microscopic scratches that harbor bacteria.
If your dentures have metal parts, check with your dental provider about which soaking solutions are safe. Some cleaning tablets contain ingredients that can tarnish or corrode certain metals over time, and your provider can recommend a compatible product.