Chlorhexidine is a powerful antiseptic commonly prescribed by dentists, often as a mouthwash, to treat gingivitis and other oral conditions. It acts as a broad-spectrum antimicrobial agent, effective against various bacteria, fungi, and some viruses. While highly effective in reducing dental plaque and preventing gum inflammation, a common side effect is extrinsic tooth staining. This discoloration can be a concern for individuals undergoing treatment.
The Cause and Appearance of Stains
The staining caused by chlorhexidine is a result of a chemical process in the mouth. Chlorhexidine is a positively charged molecule that readily binds to negatively charged surfaces, such as the tooth pellicle, which is a thin film of salivary proteins on the tooth surface. This binding allows chlorhexidine to remain in the mouth for an extended period, contributing to its sustained antimicrobial action.
Once bound, this adsorbed chlorhexidine attracts and reacts with chromogens, which are colored compounds found in foods and beverages. This interaction can lead to the formation of pigmented deposits on the teeth, resulting in visible stains. The stains typically appear as yellowish-brown to dark brown discolorations. They are most commonly observed along the gumline, in the spaces between teeth, and on the surface of the tongue. Chlorhexidine can also stain various dental restorations, including fillings, crowns, and dentures.
Factors That Worsen Staining
Several external factors can increase the severity of chlorhexidine staining. Diet plays a significant role, as certain foods and beverages contain high levels of chromogens that interact with the bound chlorhexidine. Primary culprits include drinks high in tannins, such as coffee, tea, and red wine, which cause noticeable discoloration. Dark berries and other highly pigmented foods also contribute to staining.
Tobacco use, whether smoking or chewing, is another major contributor to worsening stains. The chemicals in tobacco products combine with chlorhexidine, intensifying the staining potential. Additionally, pre-existing plaque buildup on teeth can exacerbate staining. Plaque provides a rougher, larger surface area for both the chlorhexidine and subsequent stain-causing compounds to adhere to, making the discoloration more pronounced.
Stain Removal and Prevention
Chlorhexidine staining is extrinsic, meaning it occurs on the outer surface of the teeth and is not permanent. The most effective method for removing these stains is a professional dental cleaning, which involves scaling and polishing by a dentist or dental hygienist. During this procedure, specialized tools are used to physically remove the stained deposits from the tooth enamel, restoring the natural tooth color.
For patients who must continue using chlorhexidine, several proactive measures can help prevent or minimize staining. Brush and floss your teeth thoroughly before using the rinse to remove plaque and food debris. Waiting at least 30 to 60 minutes after rinsing before eating or drinking can also reduce the interaction of chlorhexidine with staining agents from food. Avoiding stain-causing foods and beverages, especially those high in tannins, for the duration of the treatment period is also recommended. Do not use the chlorhexidine rinse immediately after brushing with certain toothpastes, as ingredients like sodium lauryl sulfate (SLS) can interfere with and potentially deactivate its effectiveness.