What is Invisalign, and is it worth it?

Invisalign is a teeth-straightening system that uses a series of clear, custom-made removable aligners to shift teeth gradually into a planned position. Whether it is worth it depends on two things that are worth being blunt about: how complex your case is, and whether you will actually wear them for 20 to 22 hours a day. See Invisalign.

For the right case and a compliant wearer, it produces results comparable to fixed braces, far less visibly. For a complex case, or for someone who will not keep them in, fixed braces are the more reliable choice — not the inferior one.

Invisalign is one brand of clear aligner. The Australian Dental Association describes the category in general terms: "Clear aligners are custom made thin plastic trays that are worn over the teeth to straighten them", and notes that "Many people will know them by their individual brand name."

How it works

Aligners are crafted from smooth plastic, made to fit your teeth precisely. Each set applies gentle pressure at planned points to move specific teeth a small distance, and you progress through the series over the course of treatment.

One expectation to set early, in the ADA's own words: "Although the aligners are clear plastic, they are not invisible." They are discreet rather than undetectable, which is a real difference at conversational distance.

The planning is done from a 3D digital scan of your teeth, from which the whole sequence of movements is designed before the first aligner is made. That gives both you and the clinician a clear picture of the intended endpoint and the route to it. See Technology.

Two elements patients are often not told about in advance:

• Attachments. Small tooth-coloured composite bumps bonded to some teeth, which give the aligners something to grip so they can produce certain movements. They are usually necessary, they are visible up close, and they are removed at the end.
• Interproximal reduction (IPR). Small amounts of enamel polished from between the teeth to create space where crowding needs to be resolved without extractions. It is minor and routine, but it is irreversible.

Neither is a drawback so much as a fact of the treatment. Ask whether your plan includes them.

The genuine advantages

Appearance. The aligners are difficult to see, which matters a great deal to many adults who would not consider fixed braces. That is a legitimate reason to choose a treatment. See How to get straight teeth without braces.

Comfort. There are no brackets or wires to irritate the cheeks and lips, and there are fewer emergency appointments for broken brackets or protruding wires. There is still pressure and tenderness for a day or two after each new aligner — that pressure is the treatment working. Compare What are the most common complaints associated with conventional braces?.

Removability. You take them out to eat and to clean your teeth, so there are no dietary restrictions and brushing and flossing are unchanged. For oral hygiene during orthodontics, this is a real clinical advantage, and the ADA's own braces instructions show why: with fixed appliances "brushing after every meal is recommended as food can get stuck around the brackets", and "Cleaning between your teeth with string floss can be tricky while wearing braces", so floss threaders or interdental brushes are needed. With aligners, the ADA's line is simply that "Your teeth can be brushed and flossed as normal when having clear aligner treatments." Decalcification marks around brackets are a well-known risk of fixed appliances. See What are the hygiene benefits of Invisalign? and Dental Cleans & Hygienists.

Planning visibility. The digital plan lets you see the intended sequence and endpoint before starting.

The requirements, stated honestly

Aligners must be worn 20 to 22 hours a day. They are removed only for eating, drinking anything other than water, and cleaning your teeth. This is the single factor that most determines whether treatment succeeds. The ADA puts the same requirement without an hour count: "The trays should be worn at all times other than when eating and drinking liquids other than water." See How to protect your aligners and your smile.

Removability cuts both ways: an appliance you can take out is an appliance you can leave out. Wearing them for 14 hours a day does not give you slower progress — it gives you aligners that no longer fit, tracking that fails, and a plan that has to be rescanned and restarted.

If you know you will not keep to it, say so at the consultation. Fixed braces work whether you are motivated that week or not, and for some people that is exactly the right reason to choose them. See Conventional braces vs lingual braces vs Invisalign.

Other practical points:

• Anything other than water must be removed for — including coffee, which stains the aligners. There is a dental reason as well as a cosmetic one: "Drinking liquids such as fruit juice or soft drink while wearing clear aligners can trap the liquids against the teeth, which can cause damage to the teeth if it happens frequently" (Australian Dental Association)
• Treatment length varies widely with complexity, from months for minor alignment to considerably longer for significant correction — see How long does orthodontic treatment take?
• Aligners must be cleaned daily, or they discolour and smell. The ADA's method: clean the trays whenever you clean your teeth, "ideally twice per day", using "an antibacterial liquid soap and a spare toothbrush", then "Rinse well following with warm water"
• They are easy to lose. A lost aligner means going back to the previous one and calling the practice — Contact Us

Where fixed braces still do better

Clear aligners are not a universal replacement, and a good clinician will tell you when they are not the right tool — the ADA says the same thing in one sentence: "Your dentist or orthodontist will advise you if clear aligners are suitable for your individual situation." Fixed appliances remain more predictable for:

• Significant rotations, particularly of round-rooted teeth like premolars and canines
• Substantial vertical movements — intruding or extruding teeth
• Closing extraction spaces and large bodily tooth movements
• Severe crowding or complex bite correction
• Growing children where growth modification is part of the plan — see Children's Braces & Invisalign and When should I take my child to see an orthodontist?
• Anyone unlikely to manage the wear requirement

There is nothing second-rate about fixed braces. As the ADA notes, "Traditional metal braces have been used for about a hundred years and are still commonly used to straighten teeth." They are the appliance with the longest track record and the widest range of achievable movement. Where the discrepancy is skeletal rather than dental, jaw surgery may form part of the plan.

Who provides it matters

Invisalign can be provided by general dentists and by specialist orthodontists. Both are legitimate. See General Dentistry and Specialist Orthodontists.

What actually determines the result is the diagnosis and the treatment plan — deciding what needs to move, in what order, whether space is needed, and whether aligners can achieve it at all. That is orthodontic judgement rather than a function of the appliance. Specialist orthodontist vs general dentist: which is best for Invisalign? goes through exactly where that judgement shows.

A reasonable approach: ask who is planning your case, what their orthodontic training is, and what happens if the teeth do not track as designed. Complex cases and cases involving jaw discrepancies are appropriately referred to a specialist orthodontist, whose registration you can verify on the AHPRA register — see Dentists & Registered Specialists and Our Team. Provider tier badges are a volume measure, not a quality one: Why should I choose a Blue Diamond Invisalign provider?.

Aligners bought online without an examination

The distinction between a planned aligner case and a mail-order one is the reason this section exists. The Australian Dental Association's position is explicit: it "do not recommend Australians have DIY orthodontic treatment. There are many risks to this treatment. They can lead to permanent damage to your teeth, gums, and jaw joints." What it recommends instead is in-person treatment "which includes a thorough assessment before starting treatment and ongoing supervision". The aligner itself is not the safeguard; the examination, the diagnosis and the review appointments are.

Retention is permanent

This is the part most often glossed over. Teeth drift for life. Whatever moved them once, they will move again without retention.

Expect to wear retainers indefinitely — typically full-time briefly, then nightly, long-term — or to have a fixed retainer bonded behind the front teeth. Anyone who had braces as a teenager and now has crowded lower front teeth is the evidence for this. See Will my teeth need retainers after I've had braces?.

Ask what retention is included in the quoted fee, and what replacement retainers cost. It is a running cost, not a one-off.

Cost

Cost varies with the complexity of the case and the number of aligners required. It is broadly comparable to fixed braces for equivalent treatment, sometimes more. See the Price Guide and What is the cost of braces?.

Worth asking before committing:

• What the total fee covers — refinements, replacement aligners, retainers
• What happens if additional aligners are needed part-way through
• What your health fund covers, and over what period
• Whether payment plans are available — Payment Plans. Where a plan is advertised as interest free, that describes the plan term only: a deposit may be required, an establishment fee and ongoing account fees may apply, and charges can apply if the balance is not cleared within the agreed period. The applicable terms depend on the provider and the amount financed, and are set out in writing before you commit

Deciding

The decision is a personal one, and it should follow an examination rather than a photograph. A consultation should establish whether your case is suitable for aligners at all, what the alternatives are, what movements are planned, how long it will take, and what retention will involve. See Complimentary Orthodontic Consultation and How do I know which orthodontic treatment is best for me?. Confirm the current terms when you book — what the appointment includes, whether records such as scans or radiographs are part of it or charged separately, and whether any deposit applies.

If clear aligners are not the right tool for your case, a good clinician will say so — and that is more useful to you than a plan that starts smoothly and stalls at aligner fourteen.

Common questions

What exactly is interproximal reduction, and how much enamel comes off?

IPR is enamel polished from the sides of the teeth, between them, to create the space that crowding needs. It is done with fine strips or discs, a fraction at a time, usually across several teeth rather than a lot from one. It is not painful and it does not require anaesthetic in most cases.

On the amount, we would rather be straight with you than confident: the independent reference material this site works from does not carry a figure for how much enamel IPR removes, so we are not going to publish one. What is certain is the part that matters for your decision — it does not grow back. Enamel is not replaced, so whatever is removed is removed for good.

The questions to ask at the planning appointment, where the answers are specific to your scan rather than general:

• How many teeth is IPR planned for, and at which stages of the series?
• What is the alternative — extraction of a tooth, expanding the arch, or accepting some residual crowding? Each has its own trade-off, and there is usually more than one workable plan.
• Will my contacts still be tight afterwards? Food packing between teeth is the complaint that occasionally follows heavier reduction.

IPR is routine and, done judiciously, unremarkable. It is worth knowing about beforehand rather than discovering at the third appointment.

Can I whiten my teeth at the same time, using the aligners as trays?

Ask before you do anything, and do not buy a kit to use in them.

There is a legal line here that surprises people. Schedule 10 of the Poisons Standard lists substances "of such danger to health as to warrant prohibition of their sale, supply and use other than in specified exempt circumstances", and it states that teeth whitening products containing more than 6% hydrogen peroxide or 18% carbamide peroxide may only be sold, supplied and used by registered dental practitioners as part of their dental practice. Those provisions are formalised in all state and territory poisons legislation. Anything above that threshold is not a consumer product in Australia, whatever the website selling it says.

There is also a sequencing point that costs real money to get wrong. Ceramic and composite do not lighten. If you have a crown, a veneer or a bonded filling in your smile line, whitening the natural teeth around it will make it stand out, and the fix is remaking the restoration rather than adjusting it — see I want to whiten my teeth but one of my front teeth has a porcelain crown.

Practically: whitening and aligner treatment are two separate treatments that can often be coordinated, and the sensible order is usually to finish the movement, settle the result, whiten, and then match any restorative work to the final shade. Raise it at the planning appointment so the sequence is decided once. See Teeth Whitening and how can I improve the whiteness of my teeth?

What happens if my teeth stop tracking the plan?

It is common enough that the industry has a word for the remedy — refinement — and knowing that in advance turns an alarming appointment into an expected one.

Tracking means the tooth is where the digital plan says it should be at that stage. When a tooth lags, the aligner no longer seats fully against it, which you can sometimes see as a small air gap at the tip. The usual responses are to hold on the current aligner longer, to add or reposition an attachment, to adjust the IPR, or to rescan and issue a new series of aligners from where the teeth actually are.

Why it happens is worth being honest about: sometimes wear time, sometimes a movement that was optimistic on the plan, sometimes an attachment that has debonded without being noticed. Only the first of those is your doing.

This is the reason for two of the questions in the cost list above, and they are worth asking in dollars rather than in principle: are refinements included in the quoted fee, and what happens if a whole new series is needed? Practices answer this differently and the difference can be substantial. Ask before you start, not at the point where you need the answer.

Are clear aligners suitable for my child or teenager?

Sometimes, and the decision turns on two things that have nothing to do with the appliance.

What the plan is trying to do. If growth is being guided — a skeletal discrepancy in a child who is still growing — that is a different kind of treatment from moving teeth within the jaws, and it typically needs fixed or functional appliances rather than aligners. The ADA leaves the judgement where it belongs: "Your dentist or orthodontist will advise you if clear aligners are suitable for your individual situation."

Whether the wear requirement is realistic. The honest part of that conversation is not about the child's character but about the practicalities — school, sport, meals away from home, and the simple fact that a removable appliance in a pocket is an appliance that gets lost. Fixed braces work regardless of motivation on any given week, and for some teenagers that is exactly the right reason to choose them rather than a criticism.

On timing, the ADA's published position is that "The Australian Society of Orthodontists' recommend children have an orthodontic assessment between the ages of 7 – 10", and that "All the adult teeth do not have to be present in the mouth for an assessment to be done. An examination at this age can allow for early intervention treatment should it be needed." Waiting until every adult tooth is through can mean waiting past the point where growth could have been used. See Children's Braces & Invisalign and when should I take my child to see an orthodontist?

Practical details

Invisalign is a registered trademark of its manufacturer. Orthodontics is a recognised dental specialty; specialist registration can be verified on the AHPRA register, or by calling 1300 419 495.

Smile Solutions, Level 1, 220 Collins Street, Manchester Unity Building, Melbourne VIC 3000. Phone 13 13 96, or theteam@smilesolutions.com.au. Monday–Friday 8.00am–6.00pm, Saturday 8.30am–1.30pm, Sunday by appointment.

Published 28 March 2024, by Dr Avi Aggarwal. General information only; it does not replace advice from your treating practitioner. Outcomes vary between individuals, and all treatment carries risks. Payment plan terms are set by the credit provider and change; confirm current terms directly before you commit.

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