Comparison
Water flosser vs string floss
Published
Note: This page contains affiliate links. If you buy through them we may earn a commission at no extra cost to you. Learn more
In short
String floss scrapes along the side of each tooth and is cheap, quiet and portable, but many people find it fiddly. A water flosser uses a pulsing jet of water to rinse between teeth and along the gumline, which many find easier, especially around braces or bridges. NHS guidance names floss and interdental brushes for cleaning between teeth, so ask your dentist or hygienist whether a water flosser suits you.
Products for this job
Compare all 8 productsOral-B iO6: Sensitive and Super-Sensitive modes, display
Check price on AmazonAffiliate linkSonicare Next-Gen 9900 Prestige: SenseIQ, 8 modes, display
Check price on AmazonAffiliate linkOral-B iO9: 7 modes, 3 heads, charging travel case
Check price on AmazonAffiliate link
Our verdict
Stick with string floss if you use it well and want the cheapest, most portable option. Consider a water flosser if floss is a struggle, or if you have braces, bridges or implants and your dental team agrees it suits you.
Cleaning between your teeth reaches places a toothbrush cannot. String floss has been the standard method for decades, while water flossers have become popular as an easier alternative. The two work in very different ways, take different amounts of time and suit different mouths. This guide compares them honestly, sets out what NHS guidance actually says, and explains when a dental professional might suggest one over the other. It does not claim either method prevents disease: the right choice is the one you will use properly, and your dental team is best placed to advise.
How each method works
String floss is a thin thread, waxed or unwaxed, that you slide between two teeth, curve into a C shape around one tooth and move gently up and down below the gumline. It physically scrapes the side of each tooth.
A water flosser pumps water from a reservoir through a narrow tip. You trace the tip along the gumline and pause between teeth while the pulsing jet rinses the gap. It does not scrape; it flushes. Countertop models plug in and hold more water, while cordless models have a smaller tank in the handle.
What NHS guidance says
The NHS advises cleaning between your teeth using interdental brushes or floss, and says your dentist or hygienist can show you the right technique and sizes. It does not give the same specific guidance for water flossers.
That does not mean water flossers are not useful. Some dental teams suggest them for people with braces, bridges or implants, or for people who cannot manage floss. It does mean you should ask your dental professional what suits your teeth rather than replacing floss on marketing claims alone.
Side by side
The table sums up the practical differences. Running costs are shown as what you need to buy, because prices vary widely.
| String floss | Water flosser | |
|---|---|---|
| How it cleans | Scrapes the tooth surface | Pulsing water jet rinses gaps and gumline |
| Time per session | A few minutes once practised | About a minute on many models |
| Ease of use | Fiddly for some, needs dexterity | Easier grip, but can splash |
| Braces and bridges | Needs threaders | Specialist tips available |
| Power and space | None, fits in a pocket | Mains or rechargeable, needs sink space |
| Ongoing purchases | Floss | Replacement tips, occasional descaling |
Who might prefer a water flosser
If you are unsure, our explainer on how a water flosser works and our guide on whether a water flosser is worth it go into more detail.
- People with fixed braces, where threading floss under wires is slow.
- People with bridges, crowns or implants, if their dental team recommends it.
- People with limited hand movement or arthritis who struggle to hold floss.
- Anyone who has given up on floss and would otherwise skip cleaning between teeth.
Who might stick with floss
Floss is cheap, silent, works anywhere and needs no electricity, water tank or bathroom space. If you already floss well and your dentist is happy, there is no need to change.
Some people use both: floss or interdental brushes for tight gaps and a water flosser for the gumline or around dental work. Whatever you use between your teeth, brush twice a day for about two minutes as the NHS advises. If you want an electric toothbrush to go with it, our premium electric toothbrush guide compares the leading models.
Getting started with a water flosser
Start on the lowest pressure setting with lukewarm water and lean over the sink. Aim the tip at the gumline and pause briefly between each tooth. Increase the pressure only once you are comfortable. Our step-by-step guide on how to use a water flosser covers settings and tips, and how to clean a water flosser explains descaling in hard water areas.
Note:Some bleeding when you start cleaning between teeth is common, but bleeding that carries on, or sore or swollen gums, is a reason to see a dentist.
Frequently asked questions
Can a water flosser replace string floss? It depends on your teeth. NHS guidance names floss and interdental brushes, so ask your dentist or hygienist whether a water flosser alone is suitable for you.
Should I floss before or after brushing? Many dental teams suggest cleaning between your teeth before brushing, but the most important thing is to do it regularly. Ask your hygienist for advice.
Is a water flosser good for braces? Many people with braces find a water flosser easier than threading floss. Your orthodontist can tell you what to use.
Do water flossers make a mess? They can at first. Lean over the sink and keep your lips almost closed around the tip so the water drains into the basin.
What you need
- Check price on AmazonAffiliate link
Oral-B iO6: Sensitive and Super-Sensitive modes, display
From: Best electric toothbrushes in the UK: premium models compared
- Check price on AmazonAffiliate link
Sonicare Next-Gen 9900 Prestige: SenseIQ, 8 modes, display