2Rank 02 of 8 · Best Electric Toothbrushes
Oral-B Oral-B iO Series 3
The Oral-B iO Series 3N won Stiftung Warentest's November 2024 round with grade 1.9, ahead of far more expensive brushes. Oscillating-rotating with a three-colour pressure sensor, at €69.
8.6BPR score
- €69Price
- approx. €194 over five yearsFive-year cost of ownership
- 2 of 8in Best Electric Toothbrushes
- 8.6BPR score 0–10
Review
What this product is
Written after the analysis, from the same sources the score is built on: the manufacturer's documentation, available studies and verified owner feedback.
The best-evidenced Oral-B here, and the model that made the point about price most clearly.
Stiftung Warentest's November 2024 round was won by the Oral-B iO Series 3N with grade 1.9 "gut", listed at €80 and now €69 — ahead of brushes costing several times as much. That result, alongside the 2025 headline that good brushing is possible under €50, is the clearest signal in this category that price does not buy cleaning.
It is oscillating-rotating with micro-vibrations — the technology with the marginal evidence edge, though a small one. A Cochrane review found plaque favouring oscillating-rotating at SMD 0.24 with a non-significant gingivitis difference, and a 2023 review found a Quigley-Hein plaque difference of 0.13 and a bleeding-site difference of 3.61. Real, small, and described by Cochrane's own authors as of unclear clinical importance.
The three-colour pressure sensor — red, green, white — is visual only and does not slow the motor. That distinction matters less than it sounds: the 36-month recession trial that supports pressure sensors used a visual sensor with a 0.8–2.5 N target zone, and no trial has ever isolated a motor-reducing sensor as better.
Battery runs about 14 days claimed, 17 measured. There is no app on the iO 3, which given the absence of outcome evidence for app coaching in general adults is not a loss.
The cost is the head lock-in. iO heads are iO-exclusive at €6.25 each — standard Oral-B round heads do not fit. Twenty heads over five years is €125, for a total of about €194. That is nearly double the Oral-B Pro 3's €3.33 heads.
Sources disagree on whether it has three or four modes.
Technical data
Specification
Figures from the manufacturer's documentation, verified against available outside sources. Values we could not confirm are marked as declared.
- Technology
- Oscillating-rotating with micro-vibrations
- Movements
- Not published by Oral-B for the iO line
- Modes
- 3 or 4 - sources disagree
- Pressure sensor
- Three-colour (red/green/white), visual only
- Timer
- 30-second quadpacer
- Battery
- approx. 14 days claimed, 17 days measured
- App
- None on the iO 3
- Head price
- EUR 24.99 for 4 = EUR 6.25 each, iO-exclusive
- Five-year cost
- approx. EUR 194
- Stiftung Warentest 11/2024
- iO Series 3N WINNER, grade 1.9 gut, listed at EUR 80
- Price
- EUR 69
Component scores
Where the score
comes from.
Four components, equal weight, each on a 0–10 scale and each resting on a named source. The overall score is their mean — the full procedure is in the methodology.
What we liked
- The iO Series 3N won Stiftung Warentest November 2024 with grade 1.9
- Oscillating-rotating, the technology with the marginal evidence edge
- Three-colour pressure sensor — the design used in the 36-month recession trial
- €69 against an €80 test price
- 17 days measured battery against a 14-day claim
- No app, which the evidence says costs you nothing
Worth knowing
- iO-exclusive heads at €6.25 — standard Oral-B round heads do not fit
- €125 of heads over five years, nearly double the Pro 3's
- Pressure sensor is visual only and does not slow the motor
- Oral-B publishes no movements-per-minute figure for the iO line
- Sources disagree on whether it has three or four modes
- The 2024 grade reaches us via t-online reporting, not test.de
Comparison
How it compares
within the category
All values come from the same analysis and are comparable only within the category Best Electric Toothbrushes.
| Product | Score | Five-year cost of ownership | Price |
|---|---|---|---|
| Philips Sonicare 5500Top score | 8.8 | €265 with genuine heads / approx. €110 with third-party heads | €75 |
| Oral-B iO Series 3This product | 8.6 | approx. €194 over five years | €69 |
| Category average8 products analysed | 7.8 | — | — |
FAQ
Frequently asked questions
Is oscillating-rotating better than sonic?
Marginally, on weak evidence. A Cochrane review of 17 trials and 1,369 participants found plaque favouring oscillating-rotating at SMD 0.24 (95% CI 0.02 to 0.46) but a gingivitis difference that was not statistically significant at SMD 0.35 (95% CI -0.04 to 0.74). The authors wrote that the difference is small and its clinical importance unclear. UK national guidance is blunter: the evidence is insufficient to conclude any mode of action is superior. Buy on comfort and head cost.
Why can't I use ordinary Oral-B heads?
The iO platform uses a different head attachment, so the €3.33 round heads that fit Pro-series brushes do not fit iO handles. That is a deliberate €6.25-per-head arrangement, and it costs roughly €60 more over five years than a Pro 3. Factor it in before choosing between the two Oral-Bs.
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