In general, mouthwashes fall into two categories: cosmetic and therapeutic. Cosmetic mouthwashes taste pleasant and are formulated to temporarily control bad breath. But these rinses do not contain ingredients that can kill the bacteria associated with malodor. In comparison, therapeutic mouthwashes include active ingredients that help reduce bad and prevent dental problems such as gingivitis, plaque, and tooth decay.

Here Edward Harsini, DDS, the owner and operator of Smile Dental Clinics in Phoenix, explains the role mouthwash plays in an oral hygiene regimen and the differences between various types of rinses.

How necessary is mouthwash to an oral hygiene regimen?

This depends on different factors. For example, if a patient has an elevated risk of caries, meaning a high tendency to get cavities, mouthwash as part of an oral care program is a great idea. Also, mouthwash would be beneficial if someone is fitted with a dental appliance, such as a bridge or prosthesis, in their mouth.

What are the different types of mouthwash, and what purpose do they serve?

Mouthwash products are always expanding. Every day, manufacturers are launching new brands with a variety of benefits, such as whitening or for gum disease. The most important ingredient in a mouthwash is fluoride, and it should be xylitol-based. This naturally occurring alcohol is found in fruits and vegetables and is a natural antibacterial that reduces the amount of plaque on the teeth, which helps to prevent patients from getting cavities.

Is it true that mouthwash can interfere with the pH of the mouth and create an imbalance in the good and bad bacteria present?

This is definitely a possibility if someone uses an alcohol-based mouthwash. These mouthwashes are not at all beneficial to a patient’s oral health. What’s more, they actually cause dry mouth. The reason companies sell alcohol-based mouthwashes is because customers buy them—not because they have medicinal value.


How effective is mouthwash in preventing and curing bad breath?

Because mouthwash helps to reduce the number of microorganisms present, it’s very effective for oral care. Anytime the level of bacteria in the mouth can be decreased, this definitely helps to freshen a patient’s breath.

What’s better: mouthwash with or without alcohol?

Without alcohol.

How long should you rinse with mouthwash?

Rinse with mouthwash anywhere between 20 to 30 seconds. Also, one of the things I want to mention because of COVID is that there is a hydrogen peroxide mouthwash that dental offices use as a prewash to help kill viruses before the doctor begins working on a patient’s mouth. In addition, there are peroxide mouthwashes dentists use.

What benefits are there to using so-called natural mouthwashes?

If this type of mouthwash supports remineralization, then it would be good for the teeth. For example, if a mouthwash doesn’t contain fluoride but has some calcium remineralization material in it, that has value.

How does mouthwash help to reduce plaque accumulation, prevent gingivitis, limit the development of tartar and reduce the risk of periodontal disease?

There are mouthwashes that doctors can prescribe for patients after they perform a deep cleaning that actually lowers the level of microorganisms in the mouth. They assist the healing process after this procedure. These therapeutic mouthwashes are worth the investment because they reduce the level of microorganisms in the mouth that cause gum disease.

How often should mouthwash be used?

Probably once or twice a day. My suggestion to patients is not to eat or drink for at least 30 minutes after using mouthwash. This allows the mouthwash to really be effective in the mouth and oral cavity.

Are there any benefits to using a mouthwash made with salt and water?

There is some research that using saline mouthwash after surgery—like a day after surgery—is good. But there is also conflicting research that says there’s no difference between rinsing with saltwater or just water that’s room temperature. To me, this is like splitting hairs.

How safe and effective are tooth-whitening mouthwashes?

Whitening mouthwashes patients can use at home might be helpful. But the efficacy of these products is questionable and related to advertising. If there is a mouthwash that can remove stains, the rinse needs to be in very close contact with the tooth for a lengthy period of time to really be truly effective. My other concern with whitening mouthwashes concerns the ingredients they contain. How healthy is it for all of these chemicals to be in our mouth for an extended period of time? This is another conundrum that I’m sure requires long-term research to provide a definitive answer.

What questions should people ask themselves before deciding on a mouthwash to choose?

First, before individuals buy a mouthwash, they should be sure they will use it. Otherwise, this is a waste of money. Next, check the list of ingredients. Anytime an ingredient in the mouthwash ends in the letters ol, that means the rinse is alcohol-based and will dry the mouth. Stay away from these kinds of mouthwash. Third, if someone is prone to developing cavities and wants to make sure their oral rinse has therapeutic effects, they should confirm that the mouthwash contains fluoride.