Invisalign clear aligners

How clear aligners work

Clear aligners are a series of thin, clear plastic trays, custom-made to fit your mouth. Each one puts gentle pressure on your teeth to move them a small step toward a planned position.^1,2 You switch to a new set every one to two weeks, as your dentist directs.^2,3,4

Aligners suit many kinds of bite problems, but not all of them. Our article Is Invisalign right for you? looks at what the research says.

Getting started

• Your teeth and jaws are assessed first. According to the American Association of Orthodontists, this usually involves X-rays, photos and digital scans.³
• Any other dental work, such as fillings, should be finished before your aligners are made, because they're made to fit your teeth as they are now.¹
• Active gum disease has to be under control before aligner treatment can start.²
• Aligners are usually made off-site, so there's a wait between your scan and your first set. Delivery can take four to six weeks.¹

During treatment

Wear time

Aligners are usually worn 20 to 22 hours a day, and taken out only to eat, drink and clean your teeth.^2,3,4 Wearing them less than prescribed can make treatment take longer and affect the result.²

Check-ups

You'll have regular check-ups throughout treatment to make sure your teeth are moving as planned.¹

Attachments and spacing

Small bumps of tooth filling material, called attachments, may be bonded to some teeth to help the aligners grip and move them. They can fall off and need replacing, and they're removed when treatment ends. Some treatment plans also include filing slightly between teeth to make room (called interproximal reduction), which can leave teeth temporarily sensitive.²

Refinements

Extra aligners are often needed to fine-tune the result. Research suggests most tooth movements may not be fully achieved with the first set alone,⁹ and Align Technology, the maker of Invisalign, describes these refinements as a normal part of complex treatment.⁵

What it feels like

Most people's teeth feel sore for a few days after starting each new set. Some people have a slight lisp at first, which usually goes away within one or two weeks. Call us if soreness doesn't ease after a few days, or if you have sharp pain.²

Eating, drinking and cleaning

• Take your aligners out to eat or drink anything other than cool or lukewarm plain water. Other drinks can cause cavities and stains, and hot drinks can warp the plastic.²
• Brush and floss after each meal or snack, before you put your aligners back in.²
• Clean your aligners each time before you put them in, with a soft toothbrush, water and a small amount of toothpaste. Keep them away from hot water and harsh chemicals.²
• Store them in their case whenever they're out of your mouth. Don't chew gum with them in.²
• Smoking or vaping with aligners in can discolour or damage them.²
• Keep up your regular check-ups and cleanings during treatment.²

Things to know before you start

Align Technology's own patient instructions list some risks. Cavities, gum disease and white spots on the teeth can develop if brushing and flossing slip during treatment. Tooth roots can shorten (root resorption), as with other orthodontic treatment. Existing crowns or bridges can come loose. Rarely, people have an allergic reaction: if you have swelling or trouble breathing, stop wearing the aligners and get medical help right away. And because teeth vary in size and shape, an ideal result isn't always possible, even when the aligners are worn as directed.²

After treatment: retainers

Teeth tend to drift back toward where they started, partly because the fibres in the gums pull on them. That's why a retainer is needed after any orthodontic treatment, aligners or braces.^4,6 Retainers can be fixed (attached to the teeth) or removable, and may be worn all the time or part of the time.⁷ Without them, another round of treatment could be needed.⁶

How long it takes, and cost

The number of aligners and the length of treatment depend on the problem being corrected.¹ Cost depends mainly on how complex your case is; the type of appliance and the length of treatment also matter.⁸ If you have dental insurance, check your plan: orthodontic coverage is often a separate benefit.⁸ Ask us about cost at your assessment.

General dentist or orthodontist?

A general dentist may provide basic orthodontic treatment or refer you to an orthodontist, a dentist who has completed a university post-graduate specialty program in orthodontics.⁷ Our dentists are general dentists. Ask us whether your case is one we treat, or one better suited to an orthodontist.