As orthodontists, we recommend water flossers often because they facilitate cleaning around braces and wires in a way that can be much easier to navigate than traditional flossing methods.
First, water flossers do NOT replace flossing. For best results, you have to mechanically remove plaque. Use the water flosser first, then brush. Once teeth are fairly clean, use a regular flossing method.
Important criteria: 1) sufficient water pressure, 2) large enough reservoir to complete the job in one fill, 3) reliability of the product/brand track record.
I don't love cordless water flossers due to the fact 1) they don't usually have large enough reservoirs to last long enough to completely clean your mouth 2) if they have large reservoirs, they are awkward and heavy to hold and handle, and 3) some don't have the same power as the corded models. Of the cordless bunch, the Waterpik Cordless Advanced is probably my favorite cordless flosser, but the attached reservoir, when filled with water, makes it awkward to handle and less portable to take on the road due to its large base.
I prefer a separate water flosser from the toothbrush. However, there are two situations where a brush/water flosser combo is worth a shot: 1) the patient knows themselves and they're inconsistent/lazy about flossing. In those cases, a built-in brush/water flosser combo is worth a try to see if it will encourage more frequent flossing. 2) If there's limited counter space in a very small, tight bathroom. The Sonic Fusion would be my favorite in this situation.
Water flossers work equally well with or without braces (i.e. there's not one specifically better for braces). The Waterpik Aquarius is probably my standard favorite for braces or without braces.
I have mentioned Waterpik because it's a solid brand that has been in the industry making water flossers for years (I had one as a kid), but other brands have put out products that have been catching up and are becoming comparable.
Electric toothbrushes in general are great for patients who struggle to brush correctly using small circular motions. However, very meticulous patients can hold the brushes against their gums too hard, which can abraid their gums and cause recession. It's not uncommon for dentists to see recession in these cases. The resulting sensitivity along the gum line, especially on the contralateral side to their dominant hand (for example, right-handers have more recession on the left, and worse hygiene on the right side of their mouths) can be bothersome.
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