A night guard is a custom-fitted oral appliance designed to protect your teeth from the damage caused by grinding and clenching, a condition known as bruxism. While intended to preserve oral health, finding the device discolored, particularly with a green tint, can be alarming. This discoloration is not a sign of a faulty material but rather a common indicator of microbial colonization on the appliance’s surface. The moist, warm environment of the mouth and the night guard’s case creates an ideal habitat for microscopic life to thrive.
The Microbial Culprits Causing Discoloration
The green color on your night guard is primarily a visual sign of a microbial biofilm. This biofilm forms when bacteria and fungi from your mouth are not fully cleaned away and are allowed to proliferate on the appliance’s surface. The most common bacterial agent responsible for a distinct blue-green color is Pseudomonas aeruginosa.
Pseudomonas aeruginosa produces a unique pigment called pyocyanin, which is a blue-green substance that readily stains the plastic material of the night guard. This bacterium is an opportunistic organism that flourishes in wet, dark conditions, making a persistently moist night guard case its perfect breeding ground. Another significant contributor to green or yellowish-green discoloration is the presence of mold or fungi, such as Candida species, which can appear in advanced stages of colonization.
The buildup of saliva and plaque on the night guard, which contains proteins and mineral deposits, provides the nutrient base for these microbes to establish themselves. When a night guard is not dried completely or is stored immediately in a closed container, the constant moisture encourages the growth of these microorganisms, leading to the visible discoloration.
Health Implications of Using a Green Night Guard
Using a night guard that has turned green is an indicator of poor hygiene and presents localized risks to your oral health. The microbial film coating the appliance serves as a reservoir for bacteria and fungi, which are reintroduced into your mouth every time you wear the guard. This continuous exposure significantly increases the overall bacterial load in the oral cavity.
The presence of a contaminated night guard can increase the risk of developing oral infections and localized inflammation. This includes conditions like gingivitis (gum inflammation) and stomatitis (general inflammation inside the mouth). The microbial buildup also contributes to chronic bad breath (halitosis) and accelerates the formation of plaque and tartar, as the appliance constantly sheds microorganisms.
Effective Strategies for Cleaning and Prevention
Preventing green discoloration requires consistent and specific cleaning habits to disrupt the microbial biofilm and eliminate the moist environment. After every use, the night guard must be rinsed under cool water to remove saliva and debris, then gently brushed with a soft-bristle toothbrush. It is important to use a non-abrasive soap or a specialized dental appliance cleaner, as regular toothpaste can be too abrasive and create micro-scratches where bacteria can hide.
For deep cleaning, soaking the night guard regularly, ideally once a week, in an approved solution is highly recommended. Effective options include denture cleaning tablets containing ingredients like sodium perborate or a solution of dilute white vinegar, which helps to break down mineral deposits and kill microbes. Alternatively, a soak in a 50:50 solution of water and over-the-counter hydrogen peroxide can also be used as a disinfectant.
A crucial step in prevention involves thorough drying and proper storage of the appliance. After cleaning, shake off excess water and allow the night guard to air-dry completely before placing it in its case. Storing the guard in a ventilated case rather than a closed, moist one inhibits the growth of the mold and bacteria that thrive in damp conditions. Avoid using harsh chemicals like bleach or boiling water, as these can damage the material of the night guard and compromise its fit and integrity.