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Is 18 hours a day enough for Invisalign?

Invisalign clear aligners have revolutionized orthodontic treatment, providing an aesthetically pleasing and comfortable alternative to traditional metal braces. One of the keys to Invisalign’s effectiveness is the patient’s compliance in wearing the removable aligners for the prescribed time each day.

Most orthodontists recommend wearing Invisalign aligners for 20 to 22 hours per day for the fastest and best results. However, many patients wonder if they can get away with less time and still achieve their desired outcome.

What Does Invisalign Require?

When you begin Invisalign treatment, your orthodontist maps out a complete treatment plan customized to move your teeth into their optimal position. They then design a series of clear plastic aligners that will incrementally move your teeth into each position along the way.

Each aligner is intended to be worn for approximately two weeks before switching to the next in the series. For the aligners to be effective, they need adequate time to apply constant gentle pressure to the teeth to encourage the movement.

Invisalign provides the following recommendations for aligner wear:

  • Aligners should be worn for 20 to 22 hours per day
  • Only remove aligners for eating, drinking, brushing, and flossing
  • Change to a new set every two weeks
  • Wear retainers after treatment to maintain results

Wearing your aligners for less than 20 hours per day reduces the amount of time they are exerting force on the teeth. This can slow down treatment progress and inhibit the aligners from moving your teeth properly.

Can You Get Away With 18 Hours of Wear?

Many patients are tempted to try to shorten their recommended Invisalign wear time. Realistically, is 18 hours of wear time enough to still achieve good treatment progress?

Every hour does count when it comes to the effectiveness of Invisalign treatment. However, some patients may be able to complete treatment successfully with slightly less than the recommended 20 hours of daily wear.

Several factors impact whether a shortened wear time of 18 hours per day may be sufficient:

  • Your specific treatment plan – Plans involving minor tooth adjustments may be more forgiving than those requiring complex movements.
  • Your tooth and jaw structure – Your anatomy can affect how easily or difficult your teeth are to move.
  • Your age – Younger patients tend to achieve faster progress than older patients.
  • Your compliance level – Wearing aligners consistently for 18 hours daily is better than 16 hours of inconsistent wear.

In most cases, 18 hours of daily Invisalign use will still produce good results. However, treatment will usually take longer overall than if you wore the aligners for the full 22 hours. It is best to discuss your particular situation with your orthodontist.

Potential Problems With Reduced Wear Time

While 18 hours per day may work for many patients, decreasing your wear time too significantly comes with risks, such as:

  • Slower tooth movement and stalled progress
  • Longer total treatment time
  • Not achieving the desired results
  • Needing additional aligners or mid-course corrections
  • Increased costs if more aligners are needed
  • Avoidable frustration from extended treatment time

Any reduction in treatment progress can mean your teeth are not being moved and straightened as planned. This can leave teeth still overlapped or crooked when aligners are changed. Your orthodontist may need to revise your treatment plan and create new aligners to get you back on track.

Tips for Achieving 18 Hours of Daily Wear

If your orthodontist approves reducing your Invisalign wear time to 18 hours per day, here are some tips to help you maximize these hours:

  • Put aligners in first thing in the morning and wear all day until dinner
  • Wear aligners for at least 4 hours before first removal
  • Aim for 8-10 continuous overnight hours of wear
  • Carry your case to reinsert aligners after meals or snacks
  • Track your wear time with the Invisalign Mobile App
  • Stick to the 2-week aligner change schedule

It is essential to maintain your prescribed aligner change schedule, even if progress seems stalled. Changing aligners keeps the teeth moving based on the initial treatment plan.

Ask Your Orthodontist About Your Options

While the Invisalign company recommends 20-22 hours of daily aligner wear for the most predictable and timely results, some patients can complete treatment successfully with slightly fewer hours of wear. The exceptions are if you have:

  • Very crooked teeth or complex dental issues
  • Experienced a lack of progress
  • Missed scheduled aligner changes

These situations usually require strict adherence to the prescribed timeline and hours of wear.

If you are hoping to wear your aligners for 18 hours per day instead of the recommended 22 hours, have an open conversation with your orthodontist. Discuss your specific treatment plan and dental needs.

Together, you can decide if slightly reducing your daily Invisalign wear is appropriate in your unique situation. Your orthodontist may approve trying 18 hours of wear time as long as you closely follow the treatment plan and report any stalled progress at your check-up visits. With their guidance, 18 hours per day may be enough for you to gain your dream smile.


Invisalign offers a more comfortable and discreet method for straightening teeth compared to traditional braces. However, aligners only work properly when worn for adequate time. Most orthodontists recommend wearing Invisalign for 20-22 hours per day for the fastest and most predictable results.

Some patients wish to shorten the recommended wear time for convenience or comfort. While not ideal, wearing aligners 18 hours a day may be sufficient if approved by your orthodontist. However, reduced wear time increases the risk of slower progress and complications. Discuss your particular treatment goals with your orthodontist to decide if decreasing your daily wear to 18 hours could work for you.

With close monitoring and smartly structured wear time focusing on overnight and all-day use, 18 hours per day may produce successful outcomes for some Invisalign patients. But for more complex cases or if progress stalls, the standard 20-22 hours of daily wear remains the safest recommendation for achieving your best smile.