That's what I used to think...
Of course they don't replace actual flossing! Haven't you ever gotten something stuck in your teeth that only floss would get out. I have some teeth that are so tight that I break the floss trying to floss between them (even with very thin floss).
For a "water jet" based device to eliminate flossing...the water jet would have to be so powerful that it would or could put a hole right thru the skin on the side of your mouth. This device is probably a great addition to a persons oral-care routine...but it's not going to replace flossing.
- Nick
Well, I just looked this up on my university's web directory of scholarly journals and actually found pretty reliable data on the topic. I scanned 5 journals published after 2005 which all pretty much reported very similar findings. I wanted to find out because I recently spent $60 on one for my 10 year old who got braces a few months ago. Though I personally supervised and even helped him with his flossing 2x's/day, the overwhelming stench that emanated from his mouth was worse than nauseating. You could literally smell him from 4-5 feet away! I asked his doc for suggestions and he insisted we purchase a water flosser. I thought he was nuts. My mom was a dental assistant and I'd flossed for years and only get pro cleanings every 5 years because I spend $80 so they can spend under 10 mins trying in vane to scrape up something, only to tell me I have "amazing" dental hygiene. I'm a germ-a-phobe and almost OCD when it comes to personal hygiene.
Anyway, I thought EXACTLY as you did, but I was desperately willing to try anything to make my son tolerable to be around. I was all set to see no results and expected that I'd have to stand in a long WalMart line to return the **** thing. Well, to my TOTAL shock, his chronic stench totally disappeared in less than a week! I'm serious. Yep. I bought one for my hubby and me the next week. OMG! Before the first time I used it, I flossed with a TwinLine flosser. Trust me, I know exactly how to floss correctly. Then I used the gizmo. I couldn't believe the crud that was still there! GROSS! I promise you, you won't believe this until you try one yourself. All 4 of us use it with a shot of mouthwash added to the water. My hubby is always kissable now...except after coffee or garlic...no flosser can fix that!
Anyway, here's what the most recent meta analysis I located had to say. BTW, I'd provide a URL, but scholarly journal access is only available to paid subscribers and students whose school pays the subscription fees to the publishers. Apparently, they compiled research data over a 50 year period, comparing string to water flossers. Important to note that only one brand, the Waterpik, was represented because of its market prevalence and mechanical consistency. This is fine by me, since that's the brand I bought. The conclusion was that this water flosser is roughly 30% less likely to cause bleeding than string floss, 3 times more effective at removing plaque and calculus (I'm assuming that's the stuff dentists scrape during cleanings). And, after viewing samples under a scanning electron microscope, they found it removes 99.9% of microbes and bio-film (I'm assuming that's a fancy word for scum) within the entire mouth, not just teeth. There's a whole lotta info I don't have time to cover, but the stats get even better for the water flosser among individuals who were flossing with string floss incorrectly. In one cited study, the team determined that 90% of those who regularly used string floss were doing it incorrectly and didn't know it! Also, it is not the PSI that causes these devices' effectiveness, they determined it is the hydraulic pulsing mechanism that supposedly makes the difference. The steady-stream faucet attachments were deemed useless.
Give one a try if you don't believe me. I wouldn't have believed me a month ago either. You have nothing to lose. Just return it. Let us know what you think if you do decide to give it a whirl! Also, it's probably not a good idea to force floss between two teeth that are so tight. My father did that for years with a stubborn gap until he literally chipped his tooth pulling out the floss! Weird.
Take care. =)