How Long Does Invisalign or Invisible Braces Treatment Take?

Written By Dr Neville Bass B.D.S., B.Sc., M.Sc., D.Orth
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published
September 10, 2026

Invisalign or invisible braces treatment can take anywhere from a few weeks to 18 months, depending on what needs correcting. 

For many patients, treatment takes around 6 to 18 months, while Invisalign states that the average treatment time is 12 to 18 months. However, if you only need a small correction to your upper or lower teeth, treatment can sometimes take just a few weeks. 

Your dentist or orthodontist will assess your teeth and give you a more accurate estimate based on your individual needs.

You can find more information about Invisalign in Harley Street at Bass Orthodontics or call us on 020 7580 8780.

What is the minimum time Invisalign treatment can take?

Very minor corrections using Invisalign can be completed in just a few weeks, particularly when treatment is limited to one dental arch or involves a small amount of tooth movement.

Some patients may only need a small adjustment to their upper or lower front teeth. In these cases, a short course of clear aligners may be appropriate. Invisalign also says that patients can start seeing results within the first few weeks.

The exact timeframe will depend on the movement required, how well your teeth respond to treatment and how consistently you wear your aligners.

How long does Invisalign normally take?

For more typical cases, Invisalign treatment usually takes between 6 and 18 months. The official Invisalign website reports an average treatment time of 12 to 18 months, although simpler cases can be completed in around six months.

More complicated cases can take longer. If you have significant crowding, larger gaps or a more complex bite problem, your treatment may need more time.

This is why it is difficult to give an exact timeframe without examining your teeth. Two people with Invisalign may have very different treatment plans.

What happens during Invisalign treatment?

Invisalign treatment starts with an assessment by your dentist or orthodontist. They will examine your teeth and may use a digital 3D scan to plan how your teeth need to move.

Your aligners are then made specifically for your teeth. Each aligner is slightly different and is designed to move your teeth gradually towards their planned positions.

You will normally change your Invisalign aligners every 7 to 14 days according to the schedule given by your dentist or orthodontist. 

Your progress will also be monitored throughout treatment. Your dentist or orthodontist will check that your teeth are moving as planned and that your aligners are fitting correctly. They can make adjustments to your treatment if needed.

Does wearing Invisalign for longer each day make treatment faster?

Wearing your aligners as instructed is important for keeping treatment on schedule. Invisalign aligners are designed to be worn for most of the day, with the exact instructions provided by your dental professional.

If you regularly leave your aligners out for too long, your teeth may not move as planned. This can affect how well the next aligner fits and may mean that treatment takes longer.

Following your dentist or orthodontist's instructions gives your treatment the best chance of progressing as planned.

Do I need retainers after Invisalign treatment?

Yes. You must wear retainers after Invisalign treatment if you want to maintain your new smile - and not wearing retainers could impact your long term results.

Once your teeth have been moved, they can naturally start to shift back towards their previous positions. This is known as relapse. Retainers help hold your teeth in their new positions while your mouth adapts.

Your dentist or orthodontist will tell you how often to wear your retainers. Some people are initially advised to wear them full time before moving to night-time wear.

Retention is not simply an optional final step. It is an important part of keeping the results you have worked towards throughout your Invisalign treatment.

Can Invisalign treatment take longer than expected?

Yes, Invisalign treatment can sometimes take longer than expected due to not wearing your retainer or teeth not moving as expected. Your estimated treatment time is a guide rather than a guarantee. Teeth do not always move at exactly the same speed, and some movements can take longer than expected.

Not wearing your aligners for the recommended amount of time can also delay progress. Missed appointments, problems with aligner fit or the need for additional aligners can affect the final treatment time.

The best way to stay on track is to follow your dentist or orthodontist's instructions and attend your recommended appointments.

Is Invisalign faster than traditional braces?

In some cases, Invisalign can be quicker than traditional braces. Invisalign reports that multiple studies have found treatment completed five months faster on average compared with braces. However, this does not mean that every Invisalign case will be faster. The most important factor is the complexity of your individual case.

How long will my Invisalign treatment take?

For some people, Invisalign treatment can take just a few weeks. For others, it may take 6 to 18 months or longer. The more straightforward the correction, the shorter treatment may be.

Your dentist or orthodontist can assess your teeth and explain how long your treatment is likely to take. Once treatment is complete, remember that wearing your retainers as instructed is essential to help prevent your teeth from moving back.