What is the scientifically proven best mouthwash?

Mouthwashes. The problem here is they all have their own "scientific" data. My take on this is somewhat complicated. Listerene is good because of a proprietary oil in their mouthwash. By brand, it is the only alcohol-containing mouthwash i recommend. The others i recommend specifically because they have no alcohol (drying of mucosa and destroy good bacteria). Non alcoholic are breath rx, act, fluorigard.
Mouthwash. Your Pharmacist would be the best one to inquire from.
It depends. It depends what you are trying to prevent. If you want to prevent cavities, use act Fluoride rinse. If you want to prevent gingivitis (bleeding gums), use listerine. If you want to prevent gingivitis and have dry mouth, use crest prohealth. (it does not have the alcohol that listerine does which can make dry mouth worse.) finally, biotene rinse can be used to specifically help with dry mouth.
contains flouride. Listerine has a high alcohol content, which is hard to tolerate for most patients. It is a great mouthwash for removing plaque from your teeth. It also has a anticavity version which contains flouride. My Next Choice would be act or the generic equivalent next to it at the store. Act is milder, better tasting, but not as good at removing plaque.