Electric toothbrush research · Denmark
You were right that Sonicare solves your gunk problem — but not for the reason you think, and the obvious upgrade would have made it worse. Six models priced across Danish and EU retail.
Every current Sonicare cleans identically — Electric Teeth scored the 5300, 5500, 6100, 6500 and 7100 all 100/100 across a 2.5× price spread, and Stiftung Warentest says cheap models are barely worse than ones costing hundreds. So the money buys ergonomics, running cost and, in your case, fewer places for gunk to hide.
HX7400/01 · white
Visible pressure light-ring, a real sensitive mode, 3 intensities, 48-day battery. The promo drops it to what POWER charges for its own 5300 — a step up that normally costs 200 kr more is currently 70 kr over the best 5500.
HX7101/01 · black
Timer, pacer, strong pressure sensor, 46-day battery, current-generation motor — the cheapest brush with everything that matters. Want white? Philips' own DK store has HX7108/02 at 512 kr delivered; do not buy the /02 on amazon.de at 672 kr.
HX9992/02 · black
The only Sonicare with a seamless button — introduced specifically to stop grime collecting in the button seam. Half the price of its replacement. But see the timing section: Elgiganten held it at 1.299 kr all summer until late August, so this is not its floor. Fallback: amazon.de at 1.488 kr.
Sonicare heads also slide onto a metal stem, and Philips' own support page tells you to wipe “the top seal (around the metal shaft)”. Anyone selling you a stem-free brush is wrong. The real difference is geometry and void volume:
The strongest evidence is negative and quite striking: five Reddit searches deliberately loaded against Sonicare (“sonicare mold inside brush head”, “sonicare black gunk brush head base”) all returned Oral-B threads instead.
This is the part that would have cost you money. The iO's magnetic coupling replaced the thin shaft with a wide hollow tube, and its heads have side vents — bigger void, worse drainage. r/oralbtoothbrush runs a standing stream of iO mould threads (“Don't Buy Any Oral-B IO Series — Mold”, 179 upvotes; most recent thread 11 days ago). Oral-B's own iO cleaning page concedes it, telling you to run water inside the top of the handle to remove “gunk”.
The problem with the IO is the tube shape of the handle and brush head… The Sonicare however is a metal tip that vibrates — it's a much tighter fit, so stuff doesn't accumulate inside. — a dental hygienist, r/DentalHygiene (~2 yrs ago). She adds that Oral-B acknowledged the issue to her directly.
Worth knowing so you can overrule this knowingly: Forbrugerrådet Tænk's April 2026 test of 95 brushes put the iO series top in several categories. It is not a bad brush. It is the wrong brush for your specific complaint.
Sonicare still has a stem and a rubber top seal, and Philips prescribes a weekly detailed clean of exactly that area. The one peer-reviewed study here (Morris et al., J Dent Hyg 2014) found solid-head brushes carried up to 3,162× less Fusobacterium than hollow-head ones — but the hollow-head brushes it tested were a Sonicare DiamondClean and an Oral-B SmartSeries, so by its logic Sonicare sits in the same category as Oral-B. It was also part-funded by the distributor of the solid-head brush that won. Directionally informative, not decisive.
And be sceptical of the health framing: nearly every “mouldy toothbrush health risk” page is dental-practice SEO content. For a healthy adult this is a disgust and product-quality problem — a completely legitimate reason to spend money, just not a medical emergency. (Also: pink or orange slime isn't mould, it's Serratia marcescens.) The highest-value habit, whatever you buy: take the head off after every use and store it so it drains. Most horror photos online are heads left assembled and used well past the 3-month replacement mark.
Since crevices are the whole reason you're shopping, here is the shortlist ranked on that axis alone. Each filled dot is a place dirt provably collects. Note the awkward result: the more expensive mid-tier brush has more buttons, and therefore more seams, than the cheaper one.
Ranked by total delivered cost, not sticker price. Every shop name and every price links straight to that seller's own product page, so you can check each one yourself — rejected rows included. Highlighted rows are the cheapest credible source for that model.
| Model | HX number | Shop | Item | Ship | Total | Notes |
|---|---|---|---|---|---|---|
| 5300 | HX7101/01 black | amazon.de | 445 | free | 445 | Sold by Amazon, −19%, next-day |
| 5300 | HX7101/01 black | Compumail | 461 | 39 | 500 | 10 in stock |
| 5300 | HX7101/01 black | Proshop | 460 | 39 | 499 | På lager, read on Proshop's own page |
| 5300 | HX7108/02 white | Philips.dk | 512 | free | 512 | Best white. Down from 749 RRP; a “register for 75 kr off” offer sits on the same page |
| 5300 | HX7108/01 white | 2smile.dk | 519 | free | 519 | Ships in 24h; W2 head. URL slug says “5400” — legacy slug, the page is a 5300 |
| 5300 | HX7108/01 white | NiceHair.dk | 540 | free | 540 | Feed price, not opened |
| 5300 | HX7108/01 white | POWER.dk | 649 | C&C | 649 | Same price POWER charges for the 6100 |
| 5500 | HX7111/01 black | Compumail | 540 | 39 | 579 | 20 in stock. Stiftung Warentest category winner |
| 5500 | HX7110/01 white | amazon.de | 582 | free | 582 | Sold by Amazon |
| 5500 | HX7111/01 black | Notino.dk | 695 | 54 | 749 | disputed A 556 kr figure sits in Notino’s structured data, but that feed publishes ex-VAT; the buy button reads 694,60. Not competitive either way |
| 6100 | HX7400/01 white | POWER.dk | 649 | C&C | 649 | −300 kr, ends 24 Sep Home delivery +49 |
| 6100 | HX7400/01 white | Compumail | 622 | 39 | 661 | 4 in stock, S2 Sensitive head |
| 6100 | HX7400 white | CS MEGASTORE | 636 | 39 | 675 | Feed price, not opened |
| 6100 | HX7406/02 blue | amazon.de | 735 | free | 735 | Includes travel case, −33% |
| 6100 | HX7400/01 white | Elgiganten | 829 | 49 | 878 | Bot-walled; total unconfirmed |
| 7100 | HX7421/01 black | Compumail | 880 | 39 | 919 | Skip — same 100/100 cleaning as the 5300 |
| 5300 duo | HX7109/01 | Proshop | 848 | 39 | 887 | 443/handle — two handles, two travel cases. Cheapest per-brush anywhere, if two is useful |
| Model | HX / variant | Shop | Item | Ship | Total | Notes |
|---|---|---|---|---|---|---|
| 3100 | HX3673/14 black | CS MEGASTORE | 290 | 39 | 329 | Fjernlager, 5–7 days. near all-time low |
| 3100 | HX3673/14 black | amazon.de | 345 | free* | 345 | Travel case + USB charger, arrives Tue. *free on first order only |
| 4100 | HX3683/54 black | amazon.de | 432 | free | 432 | Limited-time deal −21%. HX3681 is discontinued — this is the live 4100 |
| Prestige 9900 | HX9992/02 black | philips.dk | 1.429 | free | 1.429 | 1 unit left Seamless button |
| Prestige 9900 | HX9992/12 blue | amazon.de | 1.488 | free | 1.488 | Reliably stocked. Best fallback for the seamless button |
| DiamondClean 9000 | HX9911/94 | amazon.de | 1.052 | free | 1.052 | Also outgoing-gen, also at rock bottom |
| SURI Pro 2.0 | brush only | amazon.co.uk | 741 | 89 | 830 | Sold by SURI. Amazon 30-day returns instead of a self-funded parcel to the UK |
| SURI Pro 2.0 | brush only | trysuri.com | €99 | €9,50 | ≈811 | DK VAT included, import fees covered under €150. Returns are the catch |
| SURI Pro 2.0 | + UV-C case | amazon.co.uk | 916 | 95 | 1.010 | ≈50 kr over buying direct, for a one-click return path |
| Curaprox Hydrosonic Easy | entry model | Den Glade Mund | 764 | free | 764 | promo ends 20 Sep then 899 |
| Curaprox Hydrosonic Pro | CHS 200 | Den Glade Mund | 1.296 | free | 1.296 | promo ends 20 Sep then 1.525. Heads cost double |
Each line is the lowest price seen that week on pricerunner.dk — so an endpoint can sit below the spot price in the tables above. Full series, not the site's default three-month window — which hides both the real floor and the normal baseline. Two clear answers and two muddy ones.
Mostly no — and not when you'd expect. Across four years of November data, the mid-range Sonicares move 4–16% off their October/December baseline, and the month's real low usually lands in the first half of November. Black Friday week itself was repeatedly more expensive than the low set two weeks earlier.
| Model | 2022 | 2023 | 2024 | 2025 | Verdict |
|---|---|---|---|---|---|
| 3100 HX3673/14 | 352 −16% | 333 −11% | 351 −4% | 329 −6% | Today's 290 kr is below every November low ever recorded. Waiting is pointless. |
| 5300 HX7108/02 | — | — | — | 386 −13% | One year of data. ~60 kr below today — and it landed 6 Nov, not Black Friday. |
| 5500 HX7110/01 | — | — | 819 ±0% | 553 −13% | 2024 saw no November discount at all. |
| 6100 HX7400/01 | — | — | — | 583 −4% | Barely moves. POWER's current 649 kr is competitive with its November behaviour. |
| Prestige 9900 HX9992 | 1.599 −29% | 1.299 −43% | 1.169 −43% | 1.299 −30% | The one real annual event. Four years running, 29–43% off, always via Elgiganten or Whiteaway. |
Digging into the daily series undercuts the clearance story above. Elgiganten held the 9900 at 1.299 kr for the whole of June, July and August 2026 — 89 consecutive days, a sustained level rather than a promo needle. That campaign ended around 28 August, and Elgiganten has since gone back to 2.039 kr.
So today's 1.429 kr at philips.dk is 130 kr above a price that was standing three weeks ago, and 1.488 kr at amazon.de is 190 kr above it. It is still roughly half the next-generation model, and it is still the only seamless-button Sonicare — but it is not the bargain the “last unit” urgency implies. Given the 9900 has reached ≤1.299 kr in each of the last four Novembers, this is the one model on the list genuinely worth waiting ten weeks for — with the caveat that it is outgoing stock and may simply sell out first.
Buy now if you want the 3100 (already below every historical November price) or the 6100 (its November discount is negligible, and POWER's promo expires first). Consider waiting only for the Prestige 9900, where the annual pattern is strong and consistent. For the 5300, waiting for early November might save ~60 kr — not enough to keep living with the Oral-B if the gunk is what is bothering you.
Philips states on its own DK site that every Sonicare head fits every Sonicare handle (the one exception is Philips One, which isn't on this list). So head choice is free of handle choice, and the premium lines are optional. At four heads a year:
| Tier | Head | Shop | Pack | kr/head | kr/year | Notes |
|---|---|---|---|---|---|---|
| Cheapest genuine | C1 ProResults HX6018/07 | Proshop | 8 · 253 kr | 31,63 | 127 | Fjernlager 5–6 days. Bundle with a handle to clear Proshop's 800 kr free-shipping line |
| Cheapest in stock today | C1 ProResults HX6016/87 | Proshop | 6 · 200 kr | 33,33 | 133 | På lager |
| Sensitive, genuine | S2 Sensitive HX6058/87 | Proshop | 8 · 292 kr | 36,50 | 146 | The head type the 6100 ships with |
| Mid genuine | C3 Premium Plaque Defence HX9044 | Proshop | 4 · 217 kr | 54,25 | 217 | BrushSync RFID. Nice-to-have, not a cleaning upgrade |
| Premium genuine | A3 Premium All-in-One HX9094 | Proshop | 4 · 298 kr | 74,50 | 298 | What the Prestige ships with |
| Worst mainstream | C3 HX9044/88 | Elgiganten | 4 · 379 kr | 94,75 | 379 | Three times the ProResults rate for the same fitting |
| Third-party | MundFrisk own-brand black | MundFrisk.dk | 8 · 149 kr | 18,63 | 75 | 19 reviews, states plainly it isn't a Philips product. Saves ~52 kr/yr over genuine |
| Third-party, branded | Dentadan Gentle Clean | MundFrisk.dk | 8 · 169 kr | 21,13 | 85 | Established Danish oral-care brand |
Budget ~130 kr/year, not the 250–380 kr the premium shelf price suggests. The gap between the cheapest genuine head and the best third-party one is about 52 kr a year — roughly 260 kr over a five-year handle life. Real, but far too small to change which brush you buy.
On the third-party question, honestly: they fit — the click-on collar is a simple mechanical interface. You lose BrushSync (the RFID chip that auto-selects a mode and counts down to replacement), which costs nothing on a 5300 and costs you a manual mode press on a 6100. The genuine risk is bristles splaying before three months, and nobody publishes durability data on the clones. One to avoid outright: the 59 kr “compatible” 4-pack on Elgiganten is marketplace stock from a seller rated 2,52/5 across 192 ratings, with 49 kr shipping and no click-and-collect — delivered it works out at 27 kr/head, barely under a genuine ProResults.
Aggregators get these wrong often enough to matter, and several would have cost real money. Links included so you can verify each rejection yourself.
| What | Seen at | Price | Why rejected |
|---|---|---|---|
| Oral-B iO, any model | everywhere in DK, 299–2.999 kr | — | Wide hollow drive tube and vented heads make your exact complaint worse. Rejected on merit, not price or stock. |
| Next-gen DiamondClean 9900 HX9813/91 | amazon.de | 3.054 | Launch-priced, token −14% discount. The only addition over the HX9992 is an on-handle coverage display — about 1.600 kr for a screen on a toothbrush. |
| Next-gen 9000 HX9214/84 | amazon.de | 3.376 | Price inversion — 322 kr more than the next-gen flagship above it. |
| “Cheapest 3100” HX4033/26 | amazon.de | 314 | Wrong generation. Sits in the same variant strip as HX3673 and is easy to grab by mistake. |
| 5300 HX7108/02 — the SKU on PriceRunner | amazon.de | 672 | Italian import listing, no Amazon stock, third-party only. The same brush is 519 kr in Denmark as HX7108/01. |
| 4100 HX3681/33 | Proshop | 378 | “Varen er udgået” — discontinued. The stale price still shows in aggregators. |
| Old ProtectiveClean 4300/4500 HX6800 / HX6830 | Danish shelves generally | 469–649 | Previous generation, priced above a current-gen 5300. Verify the HX number, never the marketing name. |
| “Sonicare 6100” HX6877/34 | Avxperten | 2.525 | The worst listing found. HX6877 is the old ProtectiveClean 6100, sold under the same marketing name as the current HX7400/01 — at nearly four times POWER’s price for the real thing. |
| ProtectiveClean 5100 / 4300 HX6859/29, HX6807/28 | Punkt1 | 649–1.199 | Old generation at or above current-gen prices — the 4300 is listed at exactly POWER’s promo price for the current 6100. Out of stock anyway. |
| Anything at Punkt1 | punkt1.dk | — | Same catalogue and product IDs as POWER (sister chains) but it does not carry POWER’s 6100 promo — 829 kr against 649 kr for the identical product page. Useful for checking stock, never for price. |
| 3100 HX3671/11 | Proshop, via Google Shopping | 399 | HX3671 ≠ HX3673. No travel case, no USB charging case. |
| SURI Pro 2.0 | ubuy.dk | >1.088 | Google advertised 855 kr; the page says 1.088 kr excluding shipping and customs, US-spec unit needing a voltage transformer, no EU warranty path. |
| Curaprox Hydrosonic Pro, “D2C price” | curaprox.dk | 1.220 | That figure is the site's structured data, published ex-VAT. The real shelf price is 1.525 kr. A text-only scrape would have crowned this the winner. |
| Hydrosonic Pro “member price” | Webapoteket | 1.373 | PriceRunner quotes it as open pricing; it is members-only. List price is 1.525 kr. |
| Open-box units HX7108/04, HX7110/01, HX3681/23 | amazon.de Retourenkauf | 542–576 | Each costs more than, or saves under 6 kr against, a sealed unit. Pointless risk. |
| Duo 2-packs HX7119, HX8596/21, HX3675/15 | Proshop, 24hshop, avXperten | 669–4.399 | Two handles. Sticker price reads like a premium single — except the HX7109/01 duo, which is genuinely the cheapest per handle. |
| Laifen Wave LFTB01 | pricerunner.dk | 524 | No pressure sensor — disqualifying. Its “no nooks or crannies” marketing is contradicted by its own cleaning guide, which tells you to disassemble weekly and rinse the drive shaft. |
| Oclean X Pro / X Ultra | pricerunner.dk | 275–999 | Good hardware, but Oclean's own guide admits moisture trapped at the head joint “can contribute to mold growth”. No hygiene advantage over a 5300. |
| Ordo Sonic+ · Philips One · Colgate hum | various | — | No pressure sensor (Ordo, Philips One); the hum's head gap is reported as “really hard to clean” — your complaint exactly. |
Seven research agents across four price sources: pricerunner.dk and Google Shopping (both DK-resolving — confirmed “Danmark, København V” from the IP), amazon.de and amazon.co.uk, Danish retailers checked directly on their own sites, plus geizhals.de and idealo.de as EU benchmarks. Reddit was read through a browser on the warmed-up session that old.reddit.com requires.
No cross-border arbitrage worth chasing. The German benchmarks put the 6100 at 516–537 kr against 649 kr in Denmark, but neither site publishes per-offer shipping to DK nor filters to merchants that ship here — on a 600 kr item, DE shipping eats a 130 kr gap. Their real value was confirming Danish pricing on the 5300 and 5500 sits at the EU going rate rather than inflated.
Where the numbers came from. Every price in these tables was read from the seller's own product page except where a row says “feed price” — Compumail, Proshop, Notino, Elgiganten, csmegastore, hjem.dk, NiceHair and avXperten sit behind bot walls that return 403 or 429 to automated requests, so a handful of their prices come from Google's merchant feed and should be confirmed on arrival. Google's feed was measurably stale in two places (Compumail's 5300 read 448 in the feed against 461 live; CS Megastore's 3100 read 285 against 290 live).
Every proposed listing was checked visually against a reference image, not just by name. The tells that matter: the 6100 has two buttons and a light ring — a one-button photo means a mislabelled 5300/5500 or the old HX6877; the Prestige 9900 has a flush seamless button; the next-gen HX9813 replaces it with a round display.
Prices converted from EUR use the ECB reference rate of 11 Sep 2026 (7.4748). Amazon's DKK quotes are its own internal FX, not the ECB rate — they are what you actually pay, but they will not match a straight conversion.