The truth about Toothpastes and mouthwashes

Wake up in the morning and robotically, feet drag us into the bathroom. The first thing that everyone mostly does is to start brushing with that fancy electric toothbrush (in my case, manual) to clean their teeth. And then next step would be to pick that giant bottle of mouthwash, pour in a glass, and do that vigorous gargling that can wake up any bacteria in the mouth and have them pack their bags! This ritual is very thoroughly practiced by so many that no one ever dared to question if this is right? And by that I mean , what are these two products that are meant to clean our teeth? I know chemistry was never liked by most of us, but how many actually read about their mechanism of action. Another very important question that might have not even been asked is, "can one do mouthwash after toothpaste immediately, or should there be a time gap between using both?"

Rinsing after toothpaste is a common phenomenon, because we want to clear that foam from our mouth. Who wants to go around with white stuff all over their teeth and face? I think that has led to one big confusion regarding the use of mouthwashes. Everyone thinks that mouthwash rinses are like water rinses and can be done alongside brushing, but clearing that confusion is the purpose of this article. NO! You should not be using mouthwash immediately after toothpastes.

A systematic review by Kolahi and Soolari in 2006 (1) has suggested that to obtain the best results and to optimize the antiplaque effect of chlorhexidine (CHX), it is best that the interval between toothbrushing and rinsing with CHX is more than 30 minutes, possibly close to 2 hours after brushing. The reason behind this gap is CHEMISTRY! Yes, everything boils down to chemistry. Let me explain here about CHX and toothpastes. CHX is cationic (positively charged), but most of the toothpastes have anions (negatively charged particles) like sodium lauryl sulfate and fluoride. If CHX and toothpastes are used together or immediately after each other, then they combine to form some salts which is not what we want. Now, you might wonder what about other mouthwashes like Listerine or any other? NHS says that regardless of the type of mouthwash, you should never rinse immediately after toothbrushing because rinsing will wash away the concentrated fluoride in the toothpaste(2)

However, I came across an article that says that the anti-plaque activity of CHX is not altered by using chlorhexidine rinse before or after brushing with a toothpaste(3). Well, the limitations of that study are that it was done for a very short period of time (4 days) and in very healthy individuals.

So, pause a second, understand what you read and follow the advise. Have a gap of at least 30mins between toothbrushing and using mouthwash to achieve the desired effect of healthy gums.

References

1. Kolahi, Jafar & Soolari, Ahmad. (2006). Rinsing with chlorhexidine gluconate solution after brushing and flossing teeth: A systematic review of effectiveness. Quintessence international (Berlin, Germany : 1985). 37. 605-12.
2. https://www.nhs.uk/live-well/healthy-teeth-and-gums/how-to-keep-your-teeth-clean/#:~:text=Using%20a%20mouthwash%20that%20contains,mouthwash%2C%20such%20as%20after%20lunch.
3. Evaluation of the Antiplaque Efficacy of Chlorhexidine Mouthwash immediately and 30 min after Brushing with Fluoride Toothpaste - A pilot study. 2019, Volume: 11, Issue: 2, Page no. 17-21, DOI:10.26715/rjds.11_2_4