Following orthodontic treatment, retainers are used to maintain the alignment achieved by braces. These devices, whether fixed or removable, require consistent cleaning to prevent the accumulation of plaque and bacteria, which affects both oral health and the integrity of the appliance. Many users consider soaking their retainer in mouthwash, believing it will sanitize and freshen the device. However, this common practice is largely discouraged by dental professionals, as many commercial mouthwashes contain ingredients that can unintentionally damage the retainer materials.
Why Mouthwash Is Not a Recommended Cleaning Solution
Soaking a retainer in standard mouthwash is not recommended because it can lead to material degradation and undesirable aesthetic changes. Many popular formulas contain a high concentration of alcohol, typically ethanol, and artificial colorants. Prolonged exposure to these chemicals compromises the device’s structure and appearance.
The alcohol acts as a solvent, which can cause plastic or acrylic materials to become brittle, leading to micro-cracks and weakening the structure. This degradation risks compromising the fit, rendering the retainer less effective at holding teeth in their corrected positions. Furthermore, the strong artificial dyes commonly found in brightly colored mouthwashes can permanently stain the clear plastic.
This staining affects the transparency and visibility of clear thermoplastic retainers. Even alcohol-free mouthwashes contain pigments that bond to the porous surface of the plastic, causing discoloration.
How Retainer Materials React to Common Ingredients
The specific composition of a retainer determines its susceptibility to damage from mouthwash ingredients. Removable retainers are typically made from acrylic and wire (Hawley retainers) or thermoplastic polymers (clear aligner-style retainers). High concentrations of ethanol, which can exceed 20% in some mouthwashes, act as a plasticizer and solvent on these materials.
For acrylic materials, ethanol exposure can lead to drying out or crazing, which is the development of fine cracks on the surface. This damage weakens the retainer and creates microscopic pockets where bacteria can colonize more easily. Thermoplastic materials can react to alcohol by becoming cloudy or brittle, reducing the material’s flexibility and clarity.
Strong pigments permanently bond to the plastic because the surface of both acrylic and thermoplastic retainers is porous. The dyes penetrate these pores, leading to irreversible discoloration, often manifesting as a yellow or green tint.
Best Practices for Cleaning and Maintenance
Safe and effective methods should be used to clean and sanitize retainers daily. The simplest method involves gently brushing the retainer with a soft-bristled toothbrush and a non-abrasive cleaner. Mild, clear dish soap or specialized retainer cleaning solutions are excellent choices, as they effectively remove plaque and debris without damaging the material.
Avoid using standard toothpaste, as many formulations contain abrasive particles that can scratch the retainer’s surface. These scratches increase surface roughness, making the material more prone to staining and biofilm accumulation.
A deeper cleaning can be achieved once a week by soaking the retainer in a solution of one part white vinegar to one part water or by using specialized effervescent cleaning tablets.
When the retainer is not being worn, it should be stored properly in its ventilated case to keep it safe from damage. The retainer should be kept slightly moist to prevent the formation of hard tartar. Always use lukewarm or cool water for rinsing and cleaning, as hot water can cause plastic retainers to warp and compromise their fit.