Frequently Asked Questions about Clear Aligners and Invisalign

Clear aligner treatment is an orthodontic method that moves the teeth with a series of thin, clear, custom-made plastic aligners. Each aligner moves the teeth one small step as set out in the digital treatment plan; the aligners are changed in sequence at set intervals. Invisalign is one of the registered brand names for this method.

Brackets are bonded to the teeth and apply force with a wire; they stay fixed in the mouth throughout treatment. Clear aligners are removable; they come out for eating and brushing. Aligners are less noticeable and make oral hygiene easier, but to be effective they must be worn for most of the day. Which method suits you is decided at the examination, based on the type of problem and your expectations.

For a detailed comparison, see the Clear aligners or braces? page.

Because the aligners are clear and thin, they are usually not noticed when you talk. The small tooth-coloured bumps (attachments) bonded to some teeth can be seen up close. Keeping the aligners clean keeps them as inconspicuous as possible.

It can be used for many alignment problems such as crowding, gaps between teeth, and deep, open and crossbites. There are different protocols for children in the mixed dentition, for teenagers and for adults. Marked skeletal jaw discrepancies may need additional methods or surgical planning. Suitability is assessed with an examination, X-rays and a digital scan.

Untreated gum disease, active decay, being unable to wear the aligners for the recommended time and some advanced skeletal problems may mean that clear aligner treatment is postponed or a different method is chosen. These conditions are usually treated first, and orthodontic planning follows.

There is no upper age limit; it can be used in adults whose teeth, gums and supporting bone are healthy. In children, the timing of treatment depends on the erupting teeth and jaw development. Protocols for the mixed dentition cover roughly ages 6–10.

They are all examples of orthodontics with clear aligners; the material, digital planning software, manufacturing process and available auxiliary features (such as attachment designs and protocols for children and teenagers) vary by manufacturer. What matters most in treatment is correct diagnosis, proper planning and follow-up by the orthodontist.

In some cases part of the treatment can be done with braces and the rest completed with clear aligners, or the other way round. The orthodontist decides this based on the remaining tooth movements and the needs of the case.

With both methods you feel some pressure for a while as the teeth move. With clear aligners this is usually limited to the first 1–3 days after switching to a new aligner; with braces a similar period follows wire adjustments. Braces can also irritate the inside of the cheeks and lips. How discomfort is felt varies from person to person.

The duration depends on the type and severity of the problem. Mild crowding may be corrected within a few months, while comprehensive cases usually take 12–24 months. Wearing the aligners for the recommended time is the most important factor in keeping to the expected duration. Your estimated duration is shared once the digital treatment plan has been prepared.

Wearing them 20–22 hours a day is usually recommended. The aligners come out only for eating, for drinking anything other than water, and for brushing. Wearing them for less time can delay the teeth reaching their planned position and make it harder for the next aligner to fit.

Aligners are mostly changed for the next one every 1–2 weeks. Your orthodontist sets the interval according to your treatment plan; do not change aligners early on your own.

Check-ups are usually every 6–10 weeks; they may be more frequent at the start. At check-ups the fit of the aligners, whether the tooth movements follow the plan and your oral health are assessed, and the next sets of aligners are given.

Attachments are small tooth-coloured composite bumps bonded to the surface of some teeth. They help the aligner grip the tooth better and make difficult movements such as rotation and extrusion more controlled. At the end of treatment they are removed by polishing them off without harming the tooth.

Interproximal reduction (IPR) creates space by removing fractions of a millimetre of enamel from the contact surfaces of the teeth. It is done in planned, limited amounts, taking enamel thickness into account. Whether it is needed and how much is decided during digital planning; it is not used in every treatment.

For clear aligner planning, a 3D model of the teeth is usually obtained with an intraoral digital scanner. The scan takes a few minutes and no impression material is used. Tooth movements are planned on this model, and a simulation of the plan can be shared with the patient.

Digital planning software shows the stages of tooth movement and the target position in a 3D simulation. This simulation is a plan; because biological response varies from person to person, mid-course corrections (an additional set of aligners) may be needed during treatment.

Yes. Teeth do not always follow the plan exactly; in that case a new scan is taken and additional aligners are made for the remaining movements. This is a normal part of the process and is assessed at check-ups.

In many cases, space can be gained without extraction through expansion, interproximal reduction or adjusting the position of the teeth. In some situations, such as severe crowding or markedly protruding teeth, extraction may be needed. This decision is based on your records.

If there is active decay, gum disease or infection, these need to be treated before orthodontic treatment. A scale and clean is also usually recommended beforehand.

When you switch to a new aligner, it is normal to feel pressure or tenderness in the teeth for the first 1–3 days; it shows the teeth are moving. This usually eases by itself. If a sharp edge irritates your tongue or cheek, or the pain lasts more than a few days, let the clinic know.

In the first days you may have a slight lisp on some sounds. As your tongue gets used to the aligner, this mostly passes within a few days. Reading aloud and talking help you get used to it faster.

Aligners are taken out for eating. With the aligners in, drinking only plain water is recommended. Tea, coffee, fruit juice and fizzy drinks can stain the aligners if drunk with them in, and sugar trapped between the teeth and the aligner can raise the risk of decay. After eating, brush your teeth and put the aligners back in.

Rinse the aligners morning and evening with lukewarm (not hot) water and clean them gently with a soft brush. Hot water can warp the aligners; abrasive toothpastes can dull the surface. When you take the aligners out, put them in their case rather than wrapping them in a napkin; this prevents most losses.

Smoking with the aligners in can yellow them and harms oral health. Smoking also has a negative effect on gum health and on results after treatment. The aligners need to be taken out, and the teeth cleaned before putting them back in.

Let the clinic know as soon as possible. Depending on the situation, your orthodontist may advise you to keep wearing the previous aligner or move to the next one, or a new aligner may need to be made. Until it is decided what to do, having an aligner in your mouth if possible stops the teeth from shifting back.

Aligners can be worn for most sports. If a mouthguard is needed for contact sports, discuss this with your orthodontist. During intense exercise, keep drinking water.

Carry your previous aligner and the aligner case as well as the one you are wearing. If the trip is long, plan with your orthodontist in advance when the next aligners should be put in. Do not leave the aligners in a hot car or in direct sunlight.

This is not recommended. A random adjustment to the edge of the aligner can affect how it grips the tooth and transmits force. For temporary relief you can use orthodontic wax; if the discomfort continues, contact the clinic and ask for the edge to be smoothed at the clinic.

Brushing after breakfast in the morning and before bed at night is recommended. Waiting about 30 minutes after acidic food or drink, rather than brushing straight away, can help protect the enamel.

No. Mouthwashes can support brushing and interdental cleaning, but they do not mechanically remove plaque from the tooth surface, so they cannot replace brushing.

Chewies are small, soft, flexible cylinders that help the aligners seat fully on the teeth. With the aligners in, you bite on them gently with different teeth for a few minutes. Your orthodontist will tell you whether you need them and how often.

Feeling pressure for 1–3 days when switching to a new aligner is normal, and going back to the previous aligner on your own is not recommended. However, if the aligner does not fit at all or the pain is severe, contact the clinic; your orthodontist will advise you according to the situation.

Orthodontic societies recommend that most children are assessed by an orthodontist at around age 7. At this age the first permanent molars and incisors are coming through, so the bite and jaw development can be assessed. Not every child needs treatment; some are only monitored.

Consistent wear is key to the success of treatment. Family support, a clear daily routine and following progress together at check-ups make it easier. Some aligners for teenagers have colour-changing indicators that give an idea of wear time.

Clear aligner protocols for the mixed dentition are planned to leave room for erupting teeth and adapt to changing teeth. During this period the aligners may need to be updated with a new scan more often.

At lunch the aligners are taken out and put in their case; after eating, the mouth is rinsed with water and the aligners put back in. If possible, the teeth are brushed. Not wrapping the aligners in a napkin reduces the risk of losing them.

Contact the clinic right away. In most cases moving to the previous or next aligner is recommended; the orthodontist decides which aligner to wear. Going without an aligner for a long time can cause the teeth to move back.

It is usually considered once the first permanent molars and front incisors have erupted, at roughly ages 6–10. The starting time is decided more by how far the teeth have erupted and the type of problem than by age.

Some children need no further treatment after early treatment, while many need a shorter and simpler second stage once the permanent teeth have erupted. This depends on the situation at the end of Phase 1 and on how growth progresses.

Yes. A gap between the two upper front teeth during expansion is expected and usually closes by itself within a few weeks to a few months, or during the next stage of orthodontic treatment.

Pressure and tenderness in the teeth may be felt in the first days after the appliance is fitted or activated. This feeling usually eases within a few days. If pain keeps increasing, or there is a sore or something digging in, contact the clinic.

Methods that support upper jaw development are most effective at an early age; for this reason, assessment is recommended as soon as the problem is noticed, usually between ages 6 and 10. A first check-up at around age 7 helps to get the timing right.

Not always. Some crowding can be normal while the permanent front teeth erupt, and part of it may reduce by itself as the jaws grow. The amount of crowding and whether there is enough space are assessed by examination and, if needed, X-rays.

After the screw is turned, there may be a feeling of pressure and tightness in the teeth, palate and at the bridge of the nose lasting from a few minutes to a few hours. Most children describe it as bearable. If pain is severe or constant, contact the clinic.

In people who have finished growing, the growth of the lower jaw cannot be guided. In adults with mild to moderate cases, tooth position and bite can be improved; for a marked skeletal retrusion, orthodontics and jaw surgery may need to be planned together.

The aligners need to keep being worn; however, check-up appointments can be planned around the exam calendar. By talking to the clinic before busy periods, you can arrange aligner changes and check-ups together.

A slight change in speech may be noticed in the first days; most young people get used to it quickly. Because the aligners are taken out for meals, eating is not affected.

The aligners are designed taking into account the changing baby teeth and erupting teeth. If a baby tooth falls out earlier than expected or the aligner no longer fits properly, contact the clinic for a check; the plan is updated if needed.

Both methods are effective in suitable cases. Aligners offer advantages in appearance and hygiene but need regular wear; braces do not depend on wear. The choice is made together at the examination, based on the type of problem, the teenager's cooperation and the family's preference.

Wear time is set by the orthodontist's plan; usually it may need to be worn from a few hours up to 12–14 hours a day, including time at home and during sleep. Regular wear directly affects the result.

Even if the teeth look straight, the relationship of the jaws, impacted or missing teeth and the space available can only be understood through an examination and, if needed, X-rays. A single check-up at around age 7 helps decide the way forward.

Short-term thumb sucking usually does not cause lasting problems. However, thumb sucking that continues after the permanent teeth start to erupt can cause an open bite and forward tilting of the upper front teeth. Family support and, when needed, habit-breaking appliances can help the child stop.

For treatments that make use of growth, the most suitable time is usually the growth spurt, which for most children falls between ages 10 and 14. An orthodontic check-up at an earlier age helps to get the timing right.

It depends on the type of appliance and the severity of the problem. In palatal expansion, active expansion lasts a few weeks, while the appliance may stay in the mouth for several months. Functional appliances are usually worn for 9–18 months.

Especially with appliances that cover the palate, some sounds may be harder to make for the first few days. As the tongue gets used to the appliance, speech usually returns to normal quickly. Reading aloud can help speed this up.

During pregnancy gum sensitivity and bleeding can increase, so extra care with oral hygiene is needed. Ongoing clear aligner treatment can usually continue under the orthodontist's supervision. X-rays are not taken unless necessary. Before starting a new treatment, it is recommended that you talk to your orthodontist and, if needed, your obstetrician.

For details, see our article on orthodontic treatment during pregnancy.

Implants fuse with the bone and cannot be moved; however, they are often included in the plan as fixed points for moving the other teeth. Bridges and crowned teeth can affect planning; these restorations are assessed separately at the examination for bonding attachments and aligner fit.

Active gum disease must be treated before orthodontic treatment. Once gum health is under control, orthodontic treatment can be planned with follow-up together with a periodontist.

Jaw joint (TMJ) complaints should be assessed separately before orthodontic treatment. Orthodontic treatment does not solve every joint problem; the decision is made together with the relevant specialists depending on the source of the complaint.

In some cases whitening gel can be applied using the aligners; however, because colour differences can appear on teeth with attachments, whitening is mostly recommended at the end of treatment. Decide the timing together with your orthodontist.

Whitening done under a dentist's supervision with suitable concentrations does not wear away the enamel. The most common side effect is temporary tooth sensitivity. Uncontrolled and excessive use, however, can cause sensitivity and gum irritation.

In adults, the lower jaw itself cannot be brought forward without surgery; however, in mild and moderate cases the bite and appearance can be improved by changing the position of the teeth. If a marked change in the facial profile is wanted, surgical options are discussed.

If gum disease is under control and there is enough bone supporting the teeth, treatment can be planned. In these cases tooth movements are planned more cautiously and gum check-ups continue throughout treatment.

Because the palatal suture has fused in adults, skeletal expansion with a conventional appliance is limited. In suitable cases, mini-screw-assisted or surgically assisted expansion is considered. If the narrowing is dental, arch expansion with clear aligners can be an option.

It may be possible; however, because attachments do not whiten and sensitivity can increase while teeth are moving, whitening is usually planned for after the attachments are removed. The decision should be made together with your dentist.

No. Whitening affects only natural tooth tissue. If there are fillings or crowns on the front teeth, they may need to be replaced after whitening to match the new shade.

If orthodontic treatment is needed, orthodontics usually comes first; the implant is placed after the teeth have been moved into the right position. This is because an implant cannot be moved once it has fused with the bone.

Yes, in suitable cases. The plan is prepared taking into account that the implant will not move, and the teeth that need to move are positioned accordingly.

Yes. Teeth shifting back is common when a retainer is not worn. Because the shift is often limited, it can be corrected in suitable cases with a short course of clear aligner treatment. Wearing a retainer regularly afterwards is important.

Aligners do not change the colour of the teeth. However, if coloured drinks are consumed with the aligners in, the liquid trapped between aligner and tooth can cause staining and increase the risk of decay. That is why drinking only water with the aligners in is recommended.

Yes. As long as the teeth, gums and supporting bone are healthy, orthodontic treatment can be carried out at older ages too. With age, assessment of the gums and bone becomes more important.

Your concerns and expectations are heard, and an intraoral and facial examination is carried out. If needed, records such as X-rays and a digital scan are taken. With this information you are told whether clear aligners are suitable, any alternative methods and the estimated process. Details: The first orthodontic examination.

The fee varies from person to person depending on factors such as the extent of the problem, treatment length, the number of aligners needed, additional procedures and retention after treatment. For this reason, fee information is given in writing after the examination and treatment planning. We explain the factors that determine the fee on this page.

The examination and records usually take 30–60 minutes. The time can vary depending on whether X-rays and a digital scan are needed.

You can reach us by phone, WhatsApp or the examination request form. Once your request is received, a suitable day and time are arranged together. Our team speaks English.

Yes. Getting a second opinion is a patient's right, especially when extraction, surgery or long-term treatment is recommended. Bringing your previous X-rays and records can avoid unnecessary repeat tests.

No. Orthodontic problems often cause no pain. If you are unsure about the alignment of the teeth, the bite or your child's dental development, you can come for an assessment.

Because custom aligners have a manufacturing cost, the fee for clear aligner treatment is often different from braces. However, a comparison is only meaningful when the scope of both methods is assessed for the same case. You can ask for fee information for both options after the examination.

Because the fee for orthodontic treatment depends on the diagnosis and treatment plan, accurate fee information cannot be given without an examination. After the examination you can receive the treatment scope and fee in writing.

Usually not. At the first examination an assessment is made and the necessary records are taken. In clear aligner treatment, the aligners are delivered after digital planning and manufacturing. If decay or gum treatment is needed beforehand, that is done first.

General dentists can also carry out orthodontic treatment; however, for cases involving jaw development, skeletal problems or complex situations, an assessment by a dentist with specialist orthodontic training is recommended. Feel free to ask about the dentist's area of specialisation at the examination.

Teeth tend to move back towards their old positions, especially in the first months after treatment. That is why a retainer is used after treatment. Removable retainers are usually recommended full-time for a while and then mostly at night; in some cases a thin fixed wire is bonded behind the teeth. Details: Retention.

Because tooth positions can change throughout life, using a retainer long term, often indefinitely at night, is recommended. Your orthodontist sets the schedule according to your treatment.

Contact the clinic soon. A broken or loose retainer can let the teeth shift. If one end of a fixed wire has come away it may irritate your tongue; do not try to bend or pull it yourself.

On nights without the retainer the teeth may shift slightly; when you put it back in, it feels tight. If this feeling lasts a few days or the retainer does not fit, contact the clinic. Wearing the retainer regularly is the most effective way to keep the result of treatment.

Both have advantages. A fixed wire does not depend on remembering to wear it but needs careful cleaning; a removable retainer is easy to keep clean but must be worn regularly. Many patients use both together. The orthodontist chooses based on the situation before treatment and the type of treatment.

Some mild to moderate open bites of dental origin can be treated with clear aligners. For a marked open bite of skeletal origin, options such as braces, mini-screws or jaw surgery are considered.

Protruding teeth have a higher risk of breaking from knocks. Wearing a mouthguard during sport and an early orthodontic assessment are recommended.

Yes. Problems such as crowding with deep bite, or gaps with crossbite, often occur together and are addressed within a single treatment plan. The order and length of treatment are planned according to how the problems affect each other.

A large share of mild to moderate protruding teeth of dental origin can be corrected with clear aligners. If the problem is due to a retruded lower jaw, methods such as appliances or mandibular advancement during growth may be needed.

A large share of mild and moderate deep bites can be corrected with clear aligners. In advanced cases, or when a skeletal problem is also present, braces, appliances or combinations may be needed.

In suitable cases, the pre-surgical and post-surgical orthodontic stages can be carried out with clear aligners. This decision depends on the type of tooth movement needed and the surgical team's plan.

Teeth continue to move slightly in adulthood too, and crowding of the lower front teeth can increase. This is also common in people who had orthodontic treatment before but did not wear a retainer. Mild cases can often be corrected with a short course of clear aligner treatment.

Lower front teeth touching the gum behind the upper front teeth or the palate can be a sign of a severe deep bite. If there are sores or tenderness on the gum, an examination is recommended.

Mild crossbites of dental origin can be corrected with clear aligners in suitable cases. If the crossbite is due to skeletal narrowing, additional methods may be needed.

Not every bite problem causes trouble. In some cases, however, tooth wear, gum recession, difficulty cleaning or chewing problems can develop over time. At the examination, the level of these risks for you is assessed.

In cases of dental origin and mild skeletal cases, the bite can be improved with clear aligners by changing the position of the teeth. For a marked skeletal underbite in adults, surgical options are considered.

Assessment is recommended as soon as it is noticed. Methods that support upper jaw development are more effective at an early age, so waiting can reduce the options.

If the gap is due to the position of the teeth, it can often be closed with clear aligners. If it is due to small teeth, a missing tooth or a thick lip frenum, additional aesthetic or surgical procedures may be needed.

The tongue constantly pushing between the front teeth when swallowing and speaking can contribute to an open bite developing or returning after treatment. That is why tongue habits are also taken into account in the treatment plan.

During growth, some skeletal problems can be reduced with orthopaedic appliances. In adults with mild to moderate cases, tooth position and bite can be improved; however, for marked skeletal discrepancies, surgery may be needed to change the facial profile.

Usually not. Assessment during the growth years is recommended, especially for crossbites that shift the jaw to one side. Treating it early can make correction possible with simpler methods.

In most mild and moderate crowding, space can be gained without extraction through expansion, IPR or adjusting the position of the teeth. In severe crowding and some cases where the profile is also considered, extraction may be needed.

It can reopen if no retainer is worn. That is why long-term retention with a fixed wire bonded behind the front teeth and/or a night-time retainer is recommended.

In clear aligner treatment, check-ups are mostly every 6–10 weeks and aligner changes are done at home. So visits to the clinic are usually less frequent than with braces. Your orthodontist sets the check-up interval according to the needs of your case.

Because aligners are given in sets, you can spend the time between check-ups at home. However, check-ups at the clinic are needed at regular intervals throughout treatment. Your travel pattern can be discussed at the examination and the check-up schedule planned around it; long gaps between check-ups can affect the course of treatment.