A dental retainer is a custom-made orthodontic device used after braces or clear aligners to maintain the new, corrected position of the teeth. These appliances prevent the natural tendency of teeth to shift back toward their original positions, a process known as relapse. Most modern retainers are removable and made from clear thermoplastic materials or a combination of acrylic and metal wires, like a Hawley retainer. For nearly all types of removable retainers, the general rule is that they must be stored moist when not worn.
Why Retainers Must Stay Hydrated
The structural integrity of a retainer, particularly clear plastic types, relies heavily on hydration. These materials are somewhat porous and designed to absorb water to maintain their shape and flexibility. Allowing a retainer to dry out completely for a prolonged period can compromise its intended physical properties.
When these plastic polymers lose moisture, they can become brittle and much more susceptible to cracking or breaking. This dehydration also risks causing the retainer to warp or shrink slightly, changing its precise fit over the teeth. Even a subtle distortion in shape can prevent the retainer from effectively holding the teeth in place, potentially leading to unwanted tooth movement.
The need for moisture applies mainly to long-term storage, such as overnight or during the day when the appliance is not being worn. Short-term dryness, like the brief period while you are eating a meal, is typically not a concern because the material has not been out of the mouth long enough to fully dehydrate. However, leaving a retainer out on a counter or wrapped in a napkin for hours can quickly lead to the problems of brittleness and warping, compromising the orthodontic result.
Recommended Storage Solutions
When a retainer is removed from the mouth, the most straightforward and effective storage method is to submerge it in a liquid medium. Plain, cool tap water is acceptable for short-term soaking, although it is not the ideal solution for extended periods. Using cool water is important because higher temperatures can cause the thermoplastic material to soften and permanently deform.
For long-term storage, such as overnight, or for regular cleaning, distilled water is a better choice than tap water. Tap water contains minerals that can accumulate on the retainer’s surface over time, leading to the formation of white, chalky deposits known as calculus or mineral buildup. Distilled water prevents this problem because it has had these minerals removed.
Specialized retainer or denture cleaning tablets can be dissolved in water to create an effective soaking solution. These effervescent tablets help remove plaque, kill bacteria, and freshen the appliance. They often contain mild cleaning agents formulated to be safe for orthodontic plastics and should be used according to the manufacturer’s instructions for a short soak time, not continuous storage.
Common Storage Mistakes to Avoid
Exposing the retainer to high temperatures is a significant mistake, as it can irreversibly damage the precise plastic shape. Never leave the appliance in a location where temperatures can quickly rise, such as inside a car or near a heat source. The heat causes the material to soften and distort, rendering the retainer unusable because it will no longer fit your teeth.
Another common error involves using harsh household chemicals or abrasive cleaners that are not intended for dental appliances. Substances like bleach, alcohol-based mouthwash, or even standard toothpaste can etch the plastic surface, creating microscopic scratches where bacteria can hide and multiply. These chemicals may also lead to discoloration or structural breakdown of the retainer material over time.
Storing a retainer dry, especially by wrapping it in a paper towel or napkin, is a common mistake. The appliance is easily mistaken for trash and accidentally thrown away or lost. Always use the protective case provided by your orthodontist, placing the retainer inside a cool water solution when not in your mouth.