The Mouthwash Experiment

Have you ever wondered whether the type of mouthwash you use matters? Probably not, but I have. In fact, I once had a conversation with my therapist about spending over an hour at Target trying to decide which type of mouthwash to buy. While I was able to move past that specific incident of OCD, the opportunity to more thoroughly and scientifically answer the question has finally arrived.

My local Target had an unadvertised sale on Crest mouthwashes, making them cheaper than their Up & Up store brand, so I had no choice but to run an experiment. You may notice the absence of a whitening mouthwash - it was not on sale. But it will be included as the fourth variety for testing. As a group, they represent the spectrum of mouthwashes on the market, regardless of brand.

The blue and purple mouthwashes both feature sodium flouride, the standard active ingredient in toothpaste, and claim anticavity protection; the purple wash is alcohol-free. The green mouthwash features cetylpyridinium chloride and claims antigingivitis and antiplaque protection; the chemical itself is an antiseptic, so it should also offer anticavity protection. Curiously, the purple mouthwash ALSO includes cetylpyridinium chloride, though not as an active ingredient. In case you're concerned about chemical decomposition, all 3 bottles have expiration dates within a month of each other and more than 18 months from today. Whitening mouthwashes include sodium hypochlorite, otherwise known as bleach, but no active ingredients.

The testing process will be quite straightforward, using my current oral care regimen with the addition of consistency controls. My twice-a-day process includes:

1) Flossing with a Waterpik oral irrigator using lukewarm water for the duration of a full reservoir, approximately 55 seconds on the highest pressure setting. In addition to being much more consistent than string flossing, the ADHA (not ADA) claims that water flossing is a comparable, if not perfect substitute for traditional flossing.

2) Brushing for a full cycle with a Sonicare ProResults-headed toothbrush. I usually top off after the 2 minute timer expires, but the brush vibrates in 30 second intervals, so I'll be able to consistently go for 2 minutes 30 seconds. My longtime toothpaste of choice is Colgate Total Whitening gel, the only variety that includes triclosan, an antibacterial agent, in addition to the standard active ingredient of sodium flouride. I generally prefer gels to pastes for use with an electric toothbrush due to their higher viscosity.

3) Each of the pictured mouthwashes recommend 10 mL per use and feature spillover caps for accurate measurement. They also recommend rinsing for 60 seconds, which I will time with a wristwatch. One potential complication is that Crest 3D White mouthwash recommends using 15 mL and features a cap without a measurement structure, but I'll cross that bridge when I come to it.

An experiment like this wouldn't be complete without some hypotheses. I traditionally use a whitening mouthwash, but while it may brighten your smile, it doesn't seem to do much, if anything, for your oral health. The blue mouthwash only has sodium flouride, effectively making it "brushing-plus". The green mouthwash has cetylpyridinium chloride, which I'm skeptical is actually effective against plaque. The purple mouthwash has both ingredients, so it's my pre-test favorite, the Crest Pro-Health Complete Rinse.