Halitosis (bad breath), stained teeth, cavities, dry mouth, or gum disease are reasons you may consider using a mouthwash, otherwise known as a mouth rinse. There are two main categories of mouth rinses, therapeutic and cosmetic. Therapeutic mouth rinses are meant to treat or prevent conditions like dry mouth, infections, decay, ulcers, and gum disease. Cosmetic mouth rinses are meant to neutralize breath odor or possibly whiten the teeth. Some mouth rinses may be a combination of both categories. Let’s start by looking at cosmetic mouth rinses. Whitening teeth is a very common procedure. Responding to consumer demand, mouth rinse companies have ventured into this market. The ingredient added to whitening mouth rinses to “whiten” teeth is hydrogen peroxide. The concentration of hydrogen peroxide these mouth rinses is too low, and the contact time with the teeth is too short to whiten teeth. If you have whitened your teeth recently with whitening gels, these mouth rinses may offer some benefit to slow the process of re-staining. These rinses are not very effective in removing stains despite overblown marketing claims. Another cosmetic category is mouth rinses for bad breath, which fall into two groups. The first group has been around for a long time. They contain a flavoring agent like mint, cinnamon, or bubble gum to give the mouth a fresh feeling. These are effective for a very short period and are meant to mask odors. If you like the feel and do not need longer-lasting odor control, these can be refreshing. The second category contains mouth rinses with the ingredient chlorine dioxide, which targets the primary causative agent in bad breath, sulfur compounds. Chlorine dioxide mouth rinses are more effective and longer-lasting for controlling odor and will still give you a refreshing feeling. If managing the bad breath is your goal, go with a chlorine dioxide rinse, like Closys. And do not worry, chlorine dioxide is not the same as chlorine bleach found in laundry detergent, sodium hypochlorite. Therapeutic mouth rinses also have a few categories. Let’s first explore dry mouth. Dry mouth is a symptom that can be painful and may lead to other problems due to bacteria accumulation. To help with dry mouth, some rinses have lubricating additives to help maintain a moist mouth. Most of these additives do not last long but can be soothing to a dry burning mouth if used frequently during the day. Biotene is an example. Another therapeutic category is cavity prevention. These rinses contain fluoride. Fluoride rinses can be beneficial in strengthening the enamel of the teeth, which assists in cavity prevention. Many brands have fluoride. Gum disease is another category. Some mouth rinses can help in decreasing the bacteria in the mouth that cause gum disease. The original Listerine falls into this category. There is a new rinse on the market that is molecular iodine-based. This rinse is not like iodine you are used to. It is molecular iodine, which is clear, non-staining, and non-allergenic. IO Tech International has its line of IO products available through some dental offices that are beneficial in controlling bacteria and viruses. Some prescription therapeutic mouth rinses are used for more advanced conditions like rampant decay, viral ulcers, and burning mouth from chemotherapy or radiation therapy. Ask your dentist about these if they are needed. Mouth rinses are either alcohol or water-based. Alcohol-based rinses will give you that tingling/burning feeling when you rinse. Some people like that feeling some do not. Alcohol also dries the mouth, so if dryness or sensitivity is a problem, use a water-based rinse. One last consideration is that warm salt water or salt with baking soda rinses are soothing and promote healing of the cheeks, gums, and tongue. If you want a soothing rinse that promotes healing and homeostasis in the mouth, this is a great and inexpensive option. However, these will not do much for cavity control or lasting bacterial or viral reduction. The bottom line decides why you want a mouth rinse and find one that suits your needs. Your dentist or dental hygienist is an excellent resource for this information. Dr. Robert A. Gallegos is a Fellow in the Academy of General Dentistry, visiting faculty of Spear Education, a member of the American Academy of Dental Sleep Medicine, the American Academy of Cosmetic Dentistry, and the American and Virginia Dental Associations. Dr. Gallegos practices dentistry in Middleburg, VA. www.MiddleburgSmiles.com.