电动牙刷怎么选：4项标准与研究证据

On the shelf, every electric toothbrush boasts a big Hz number and a long list of modes, which makes buying one confusing. How to choose an electric toothbrush gets much simpler if you look at four groups of criteria: type of motion, modes and timer, bristles, and battery. This guide goes through each one, along with what the research does and does not say.

Where does an electric toothbrush beat a manual one?

The detailed comparison is in our article are sonic electric toothbrushes any good. Two further studies add to it:

• Thomassen et al. (2022): a network meta-analysis of 28 publications with 56 comparisons after a single brushing. Powered toothbrushes removed more plaque than manual ones, with high certainty but a small effect. PubMed
• Pitchika et al. (2019): followed 2,819 adults in Germany for 11 years. Powered toothbrush users showed slower deepening of gum pockets and attachment loss, and kept 19.5% more teeth than manual brushers. This is an observational study, so it cannot prove cause and effect. PubMed

The NHS still stresses that electric or manual matters less than cleaning every surface of every tooth, for about 2 minutes, twice a day (NHS).

How to choose an electric toothbrush: 4 criteria

1. The type of motion and vibration frequency of the brush head.
2. The modes you actually need, plus a brushing timer.
3. Soft bristles and replacement heads that are easy to buy.
4. Battery capacity and a charging method that suits your routine.

Type of motion and frequency

There are two main types: round oscillating-rotating heads, and elongated heads that vibrate side to side at high speed (sonic). Here is what the research shows:

• Cochrane review by Deacon et al. (2010): 15 trials, 1,015 people. Because too few trials compared the same type of action, the authors could not say any type was superior. PubMed
• Clark-Perry and Levin (2020): pooled 12 trials. Oscillating-rotating brushes came out slightly ahead on whole-mouth plaque and number of bleeding sites, but showed no difference on two other gum indices. PubMed
• Thomassen et al. (2022) rated the advantage of oscillating-rotating over sonic as very small, with moderate certainty.

Inmax currently distributes sonic toothbrushes only, so we will be clear: recent reviews lean slightly towards oscillating-rotating brushes, but that gap is far smaller than the effect of brushing for the full time every day. As for frequency, the Hz figure only tells you how fast the head vibrates; lower frequencies usually feel gentler for beginners, and studies do not rank cleaning power by Hz.

Modes and timer

Look for one gentle mode (often called Sensitive or Soft) for days when your gums feel tender, and one standard cleaning mode for daily use.

A timer helps you brush for the full 2 minutes; many models also pulse every 30 seconds to tell you to move to the next part of your mouth. Vinmec, a Vietnamese hospital group, also lists the timer as an advantage of electric toothbrushes (Vinmec, Vietnam). If you tend to brush hard, favour a model with a pressure sensor, or train yourself to hold the head very lightly. Ask the seller or read the manual to confirm exactly which of these features a model has.

Bristles and replacement heads

• Choose soft bristles and a head small enough to reach your back molars.
• Check that replacement heads are on sale, fit the handle and are reasonably priced — this is a cost you will pay regularly for years.
• Spare heads in the box are a bonus. For when to change heads, see how often to replace an electric toothbrush head.

Battery and charging

A rechargeable battery is more convenient than disposable ones, especially when travelling. A USB Type-C port lets you share a cable with your phone. IPX7 water resistance means the brush can handle water while you brush and rinse it; it does not mean you can charge it while the port is wet. Charging habits that extend battery life are covered in how to charge a water flosser battery properly, which applies to electric toothbrushes too.

How to choose an electric toothbrush for different users

• Switching from a manual brush: start with a lower frequency to get used to the vibration.
• Sensitive gums or gum recession: soft bristles, a gentle mode and no pressing; see also gum recession: causes and care.
• People with braces: read our dedicated article electric toothbrushes for people with braces.
• People with limited hand movement: Vinmec includes older adults and people with arthritis or disabilities among those who should consider an electric toothbrush, since manual brushing is hard work for them.
• Children: need a small head and adult supervision; see electric toothbrushes for children.

Common mistakes when buying

• Chasing the highest Hz or the most modes and ignoring how comfortable the brush feels.
• Forgetting to budget for replacement heads over several years.
• Trusting certification labels without checking. For example, the ADA Seal of Acceptance is a programme of the American Dental Association: the ADA's Council on Scientific Affairs reviews evidence of safety and effectiveness, and the Seal lasts 5 years (ADA). If a product claims the Seal, you can check it on the ADA website.
• Not asking about the warranty and who handles repairs.

Suggested Inmax electric toothbrushes

All four models are sonic toothbrushes running on a 1,200 mAh battery with USB Type-C charging, rated IPX7 waterproof and covered by a 24-month warranty:

• M1: 120–140 Hz, the gentlest vibration in the M range; 5 modes: Clean, Refresh, Whitening, Polish, Sensitive.
• M3: the same 5 modes as the M1 but vibrating at 248–320 Hz, black body, with 2 extra brush heads in the box.
• M2 Art: 250–400 Hz, the strongest in the M2 family; colour icon display, 5 modes including both Soft and Power.
• M5: slim 199.4 mm body, 20,000 vibrations per minute; its 4 modes include Gum Care and Sensitive.

To line the models up side by side, use the comparison page; for more questions, contact Inmax. Shops that want to stock them can read the dealer policy.

Frequently asked questions

Are sonic toothbrushes worse than rotating ones?

Reviews show oscillating-rotating brushes slightly ahead on a few measures, but the difference is very small. Brushing correctly and for long enough matters more than the type of motion.

Should I buy an electric toothbrush with a pressure sensor?

It helps if you tend to brush hard. If your brush has none, hold the head lightly against your teeth and let the motor do the work.

Can an electric toothbrush replace dental floss?

No. The spaces between teeth still need their own cleaning, with floss, a water flosser or interdental brushes.

This guide gives you a better basis for choosing a toothbrush; it does not replace your dentist's advice about your own teeth and gums.