What the clinical evidence shows
Most oral hygiene claims are opinion. Waterpik vs flossing is one of the few areas with strong randomized-controlled-trial data. Here is what the peer-reviewed research actually shows:
Waterpik vs flossing — clinical evidence summary
| Ingredient | Dose | Role | Evidence |
|---|---|---|---|
| Plaque removal | Waterpik +29% | Waterpik removed 29% more plaque than string floss after single use (Lyle et al. 2013, J Clin Dentistry). | RCT |
| Gingivitis reduction | Waterpik +29-93% | Water flossing reduced gingivitis 29-93% more than string floss across multiple 4-8 week studies. | 5+ RCTs |
| Bleeding reduction | Waterpik +29-52% | Less gum bleeding after 4 weeks versus string floss in Sharma et al. 2005, J Clin Periodontology. | RCT |
| Braces cleaning | Waterpik 3x more effective | For orthodontic patients, water flossing far outperformed floss threaders (Sharma et al. 2008). | Strong evidence |
| Implant maintenance | Waterpik superior | Lower bleeding and inflammation around implants with water flosser vs floss (Magnuson et al. 2013). | RCT |
| Plaque score | Waterpik +70% | Water flossing + brushing removed 70% more plaque than brushing alone across studies. | Consistent finding |
| Pocket depth | Waterpik + mouthwash reduced most | Waterpik with chlorhexidine produced greater pocket reduction than string floss (Jolkovsky et al. 1990). | Historical RCT |
The verdict from dental literature: Waterpik is not just equivalent to flossing — it is measurably better in most clinical endpoints. The ADA accepts water flossing as an effective interdental cleaner, and the American Academy of Periodontology specifically recommends it for patients with braces, implants, crowns, and bridges.
How each method actually cleans your teeth
String floss: mechanical contact
A length of nylon or PTFE thread is inserted between teeth and pulled along the tooth surfaces to scrape off plaque. The physical contact is highly effective at removing adherent biofilm on smooth tooth surfaces. Good technique requires wrapping the floss in a "C" shape around each tooth and moving up-down along the surface.
Problems: (1) most users floss incorrectly (straight sawing motion misses the tooth surface); (2) only about 30% of adults floss daily; (3) physical thread cannot reach below the gumline where bacteria in gum pockets matter most; (4) frays and snags on crowns, fillings, or braces.
Water flosser (Waterpik): pulsating water jet
A motorized unit pulses water at controlled pressure (10-100 PSI in most Waterpik models) through a narrow nozzle. The user aims the jet at the gumline and between teeth. The combination of pulsation (1,200+ per minute) and pressure dislodges plaque, food debris, and bacteria, while reaching 3-6mm below the gumline where floss cannot reach.
Advantages: reaches deeper into gum pockets, effective around orthodontic appliances, less technique-dependent, flushes bacterial biofilm rather than pushing it around, gentler on inflamed gums.
Who should use which
Choose Waterpik if you:
- Have braces, retainers, or Invisalign
- Have dental implants, crowns, or bridges
- Have gum disease (gingivitis or periodontitis)
- Have arthritis or limited manual dexterity
- Struggle with flossing technique or hate flossing
- Want the deepest cleaning for chronic bad breath
- Are diabetic (higher gum disease risk)
- Have crowded teeth with tight contacts
Best model: Waterpik Aquarius WP-660 — our top all-around pick.
Stick with String Floss if you:
- Are on a strict budget ($3 vs $60+ upfront)
- Travel frequently and don't want to pack a flosser
- Have normal dental hygiene with no special needs
- Dislike the splatter of water flossing
- Have excellent flossing technique already
- Live in an area with unreliable electricity
- Need a backup method for travel
Pro tip: use floss tape (wider, gentler) rather than thin waxed floss — less likely to cut gums. Dental floss in a picks format (Oral-B Glide Floss Picks) is easier for beginners.
Why using both is the optimal approach
Dental hygienists and periodontists increasingly recommend using both tools daily for users serious about oral health. The combined protocol delivers what neither alone can:
The dual protocol (60 seconds total)
- Water flosser first (30 seconds) — dislodges food debris, flushes bacterial biofilm, reaches below gumline. Use at medium pressure initially.
- String floss second (20 seconds) — physical "C"-shape polishing of each tooth surface. Use waxed or PTFE floss.
- Brush last (2 minutes, the non-negotiable foundation) — removes remaining plaque and applies fluoride.
This is the protocol most periodontists use on their own patients. Waterpik for depth, floss for surface contact, brush for polish and fluoride.
Which Waterpik model should you buy?
Waterpik sells 15+ models. Here are the three that matter:
Waterpik Aquarius WP-660
Best Overall · $50-70 · 4.7/5The gold standard. 10 pressure settings, 90-second reservoir, 7 interchangeable tips (standard jet, orthodontic, pocket, plaque seeker, etc.), ADA-accepted, 3-year warranty. If you are buying one water flosser, buy this one.
Check Waterpik Aquarius on Amazon →Waterpik Cordless Advanced 2.0 WP-580
Best Portable · $70-90 · 4.5/5Waterproof (shower-safe), rechargeable battery (45 days per charge), 3 pressure settings, compact. Smaller reservoir (~45 seconds) is the trade-off for portability. Best for users who travel or want to use in the shower.
Check Waterpik Cordless on Amazon →Waterpik Sonic-Fusion 2.0 SF-04
Premium Combo · $180-220 · 4.4/5Combines a sonic electric toothbrush and water flosser in a single handle. Brushes and water flosses simultaneously. Saves counter space. Worth it if you want both tools without buying two separate devices.
Check Sonic-Fusion on Amazon →For the full rundown on water flossers across all price tiers, see our best water flosser 2026 guide.
Cost of ownership over 5 years
5-year cost: Waterpik vs string floss
| Ingredient | Dose | Role | Evidence |
|---|---|---|---|
| String floss (weekly roll) | ~$40 | 52 rolls × $0.75/roll over 5 years. No upfront cost, just recurring. | Cheapest option |
| Waterpik Aquarius | ~$60 | One-time purchase. 3-5 year life. Reservoirs are washable. | Mid-range |
| Waterpik + tips replacement | ~$100 over 5 years | Initial + replace tips every 3-6 months ($10-15 each). | Full ownership |
| Waterpik Sonic-Fusion | ~$300 over 5 years | Premium unit + brush head replacements. Replaces TWO tools (electric brush + flosser). | Combo value |
| Professional cleaning (twice yearly) | ~$1,500 | Regardless of home tool choice — still needed. | Non-negotiable |
Cost difference over 5 years: string floss saves ~$60 over Waterpik. Given the measurable health benefit and typical ROI of better oral hygiene (fewer cavities, fewer extractions, less periodontal work), Waterpik is clearly cost-effective for the long term.
Final verdict
For most people in 2026: a Waterpik is a smart upgrade over string flossing alone. The clinical evidence is consistent, the ADA accepts it as floss replacement, and the per-use cost is comparable over the long term. The Waterpik Aquarius WP-660 is the model to buy.
That said, string floss is not obsolete. For travel, budget-conscious users, or those with excellent flossing technique and no special circumstances, daily string flossing is genuinely effective. The best interdental cleaner is the one you actually use daily — choose based on what fits your life, not what sounds better in theory.
Ideal combined approach: Waterpik daily, string floss 2-3 times per week. Best of both worlds with minimal additional effort.
FAQ
Is a Waterpik better than flossing?
For most people, yes — a Waterpik removes 29% more plaque than traditional floss and 51% more than air floss, according to the 2013 Journal of Clinical Dentistry study. Water flossers are also 29-93% more effective at reducing gingivitis in randomized trials. That said, dental associations recognize both methods as effective when used correctly. The real answer: use both if possible (Waterpik first to dislodge debris, floss second for final polish), or use whichever one you will actually do daily. Compliance matters more than choosing "the best."
Does a Waterpik replace flossing?
Yes — the American Dental Association and Waterpik both state that water flossing is an acceptable alternative to traditional flossing when used correctly. It is officially accepted as an effective interdental cleaner. That said, traditional floss has two advantages: (1) physical "scraping" of the tooth surface that water pressure cannot fully replicate, and (2) portability (no batteries or charging). Most periodontists recommend Waterpik as replacement for flossing, especially for users with braces, implants, bridges, or limited manual dexterity.
What are the downsides of a Waterpik?
Main downsides: (1) upfront cost — $40-100+ vs $3 for dental floss; (2) counter space for the unit and reservoir; (3) messier than floss (water splatter — best used in shower); (4) electric dependency (won't work if power is out); (5) cordless models need battery replacement. That said, Waterpik products last 3-5+ years. Over that period, per-use cost is comparable to floss. The splatter issue resolves with practice — most users learn to keep mouth closed during use.
Should I floss or Waterpik first?
If you use both: Waterpik first, then floss. The water jet dislodges larger food particles and flushes bacteria, making your floss more effective at polishing the tooth surface. Most dental professionals agree this order. Alternative approach: use Waterpik daily and floss 2-3 times per week — gets most benefit with less effort. Users with gum disease or braces should follow their periodontist or orthodontist's specific sequence.
Which Waterpik should I buy?
For most users: Waterpik Aquarius WP-660 ($50-70) — best combination of features, 10 pressure settings, 1-minute reservoir, ADA-accepted, bestseller for 5+ years. For travel: Waterpik Cordless Advanced WP-560 ($60-80) — portable, waterproof for shower use. For premium: Waterpik Sonic-Fusion 2.0 ($180-220) — combines electric toothbrush and water flosser in one tool. Budget: WP-100 ($35) — basic but effective. Avoid: any Waterpik under $30 (usually off-brand dupes with worse pressure control).
Can a Waterpik heal gum disease?
A Waterpik alone cannot cure gum disease, but it is one of the most effective home tools for managing it. The 2005 Journal of Clinical Periodontology study showed Waterpik users had 26% more bleeding reduction than string floss users over 4 weeks. For gingivitis (reversible early stage), daily Waterpik + proper brushing can reverse the condition. For periodontitis (advanced), Waterpik is adjunct to professional scaling and root planing — it helps prevent recurrence but does not replace professional care. Use the Pik Pocket tip at lower pressure for periodontitis maintenance.
Are cheaper water flossers as good as Waterpik?
Some budget brands (H2Ofloss, Nicefeel) perform adequately for the price but lack Waterpik's track record and warranty. Cheap water flossers under $25 typically have: weaker pressure output, fewer nozzle options, shorter motor lifespan, and inconsistent quality control. Waterpik has 60+ years of R&D; the pressure consistency and reliability justify the premium. If budget is tight, refurbished Waterpiks on Amazon ($30-40) outperform new budget brands.
Waterpik Aquarius — the water flosser that wins every comparison
10 pressure settings, 7 tips, ADA-accepted, 3-year warranty. Remove 29% more plaque than string floss starting tonight.
Check Waterpik Aquarius on Amazon →