Introduction to Invisalign

Introduction to Invisalign

What is Invisalign?

Invisible braces as an easy and comfortable alternative.

Nobody likes having bad teeth. If you have a crooked smile as an adult, chances are you are already looking into what options you can get that aren’t visible to the naked eye. Retainers are fine for minor problems, but for a lot of people retainers just don’t do enough aggressive correcting to fix the problem in a timely manner. For children, braces are always an option, but they may not be the best option out there. Invisalign is the alternative for people who want to fix their teeth without having to announce it to the world.

The Invisalign process starts with a visit to the dentist. At first, not much is done, but they will examine your teeth and discuss your options with you. The dentist can give you an idea of what expectations are realistic and what time frame you are looking at. He will also answer your questions as to how the aligners are used, how much the whole process will cost, and how long you have to wait to get started with the correction process.

A plaster mold of your teeth is then cast and dispatched to the Invisalign lab. They analyze it and determine what changes need to be made to your teeth using 3D software. The plans are then sent to the dentist who analyzes them and approves the plan of action. Then, customized trays (known as aligners) are made using your teeth as a guide. These will be of a shape unique to you alone.

You will need to wear your plastic aligners for some time, around 6 months usually, swapping trays every 2 weeks. Each new aligner moves your teeth progressively towards their ultimate destination, a winning smile. The aligners stay in your mouth every moment of the day, and should only be taken out for two things: To eat something, and to brush your teeth (and floss, of course). Otherwise, they must always be in your mouth. This is not as tough as you might think!

As the name suggests, these aligners are invisible to anyone who doesn’t already know they are there, so it won’t be an issue during social situations. When eating out, simply take them out in the car or in the restroom if you don’t want anyone to know you’re wearing them.

How does Invisalign work?

The treatment process for Invisalign is basically as follows:

  1. You go to your orthodontist and they take rubber impressions of your teeth, along with photos of your teeth at different angles. These are sent to Invisalign.
  2. Invisalign develops a 3D computer model of your teeth ‘as is’.
  3. Invisalign works with your orthodontist to develop a similar 3D computer model of how you teeth should be, and also the actual path that your teeth must move in order to move from the starting position to the ending position. This animation is known as the ‘clincheck’, and you will usually get a copy of it to watch on your own computer.
  4. Apparently your teeth can safely move approximately 0.25mm every 2 weeks, so they take snapshots of your teeth during the animation at 2 weekly intervals. Invisalign makes plastic moulds (aligners) to represent these snapshots, so the end result is a customized sequence of plastic moulds to go from the current position of your teeth to the perfect position.
  5. You wear each plastic aligner for 2 weeks before discarding it, and your teeth gradually change position according to your ClinCheck. You have regular appointments with your orthodontist to ensure that your teeth are moving according to the treatment plan.
  6. At the end of the treatment duration, your teeth should be straight!

Invisalign Buttons

During Invisalign treatment, some people require “buttons”, which are small pieces of metal or plastic that work as hooks for small elastic bands.

Some people think buttons are the same as “attachments” but they are NOT the same. Attachments seem to be quite common with Invisalign, whereas buttons are less common.

The main point of buttons and elastics is to “pull” the teeth from the gums slightly, either straight out or on a particular angle. The purpose of buttons is to hold elastics, and the purpose of elastics is to close gaps between the top and bottom teeth. Many patients with traditional metal or ceramic braces also need to wear elastics to close gaps in their bite.

Unlike attachments, which are blobs of tooth cement, buttons are physical hooks that your Invisalign dentist or orthodontist sticks on your teeth using tooth cement. The buttons are generally stuck to the base of the teeth near the gum line.

The elastics can connect your top and bottom teeth in different formations, depending on the angle that is required to move your teeth into the correct position. For example, your orthodontist may attach three buttons and tell you to wear elastics in a triangle formation, or you may have four buttons to create a square shape with the elastic.


A clin-check is a 3D animation that shows how your teeth will move from their current (‘before Invisalign’) position to their final (‘after Invisalign’) position.

The starting point for the clin-check is the impressions (or 3D scan), x-rays and photos that the Invisalign doctor takes of your teeth before you get your trays. Your doctor then works with Invisalign to figure out the final position for your bite and teeth, plus the way that the teeth need to move to get there.

The clin-check is then used to create your Invisalign trays by taking snapshots of your teeth during the animation that reflect where your teeth would be every 2 weeks. These snapshots are then used to create the Invisalign aligners that you will wear throughout your treatment. (So if you imagine turning the video into a sequence of snap-shot pictures, each pair of Invisalign trays gets your teeth to the next picture in the sequence.) You then wear the Invisalign aligners to gradually change the position of your teeth according to your clin-check.


Before you start Invisalign, your orthodontist or dentist will need to get a model of the way your teeth are at the moment. They do this by creating an ‘impression’, which is an imprint of your teeth with enough detail that it enables an exact replica of your teeth to be made. These physical impressions are made using putty (which is something like Play-Doh™).

Taking the impressions is normally completely painless and takes only a few minutes, although some people may find it a bit uncomfortable, particularly those with a strong gag reflex. There is also a new alternative that some Invisalign providers now offer in their offices where 3D digital scans are taken with computer imaging technology rather than physical impressions.

Once your impressions (or scans) have been taken, they are used as the ‘starting point’ (along with your photos and x-rays) to create your clin-check.

You’ll probably only need to get one set of impressions taken, unless your treatment doesn’t work as expected and you need either a mid-course correction or a set of refinement trays once you’re done with your first set of trays. In these cases, you’ll probably get new photos and impressions taken before the new Invisalign trays are ordered.

iTero 3D Scanning

Some Invisalign providers now offer ‘impressionless scanning’ that can be used to create a 3D model of your teeth that your doctor can use as a basis for your Invisalign treatment plan.

The scan is an alternative to taking putty impressions. If you would prefer a scan rather than impressions, you may like to search for an Invisalign provider who offers this service, which is known as the Cadent iTero™ Digital Impression System.

The iTero website gives the following advantages of their digital scanning technology over traditional impressions:

  • improved accuracy and precision
  • more comfortable
  • faster (no need to wait for the putty to set)
  • no messy putty that may cause gagging

They also state that the scans are performed with visible light, with no exposure to radiation.

Invisalign Treatment Plan

Before you start Invisalign, your orthodontist will examine your teeth and create a treatment plan for your case, which describes what will need to happen in order for you to achieve the straight teeth that you want.

This includes information like the orthodontic appliances that will be used (e.g. Invisalign or ceramic braces), the estimated treatment duration, as well as specific techniques that will be used such as slenderizing some teeth, sticking on cement ‘attachments‘, tooth extraction, or using buttons and elastics.

Your orthodontist will also consider retention – i.e. which type of retainer(s) will be used to stop your teeth from moving back into their natural alignment after your Invisalign treatment.

When using Invisalign, part of the treatment plan will be represented in the video animation ‘clin-check’, which shows how the teeth should move at each stage of your treatment.

To create your treatment plan, your orthodontist will likely examine your teeth, jaw and bite alignment, and look at your x-rays. They should also factor in your own personal goals – i.e. the results you’d like to achieve with your treatment.

Invisalign Provider Status Levels

Invisalign doctors sometimes advertise themselves with labels such as “Elite Invisalign Provider” or “Premium Preferred Invisalign Provider”. But what do they mean?

These designations are part of a ‘ranking system’ that Align Technology, Inc. (the company behind Invisalign) uses to describe the doctor’s experience level with Invisalign.

To start with, each orthodontist or dentist who would like to treat patients with the Invisalign system must complete a specialized Invisalign training program. Then, the levels of experience that Invisalign providers can earn begin with Provider and continue upward to Preferred Provider, Premier Preferred, Elite Preferred, and Super Elite. Invisalign states on their website that these designations “are primarily based on the relative number of historical Invisalign cases a dentist or orthodontist has submitted.”

However, this provider status actually seems to be associated with the dental practice rather than with specific orthodontists or dentists, i.e. “Where multiple Invisalign providers are associated with a single combined practice, the Invisalign Advantage Program designation reflects that of the dentist or orthodontist with the most Invisalign cases submitted.” So you should always ask about the individual Invisalign experience of any doctor you consider.

Invisalign also states on their website that “It is your responsibility to independently determine if a particular provider is right for you. Align makes no guarantee or assurance of any particular treatment outcome or that you will be an eligible candidate for Invisalign treatment. Only a licensed dental professional who has completed Invisalign training is qualified to determine if Invisalign treatment is right for you.”

So do your research when choosing a provider, and remember that more experience might mean more practice, but that does not always mean better results!

Interproximal Reduction

As part of their Invisalign treatment, some people will require a procedure known as Interproximal Reduction. This process essentially means that your orthodontist ‘shaves’ the sides of certain teeth to make more space between your teeth for them to move into place. This shaving procedure is also known as stripping or slenderizing, but the technical term is Interproximal Reduction (IPR).

Can you notice the gaps?

The required width of the gap depends on your individual case. Here are some photos of teeth taken directly after shaving was performed, with the gaps indicated. The side IPR was 0.4mm and the one between the front teeth was 0.2mm.

If the shaving is performed correctly, your teeth should not have noticeable gaps at the end of your Invisalign treatment – in fact, the gaps are only made so that the teeth can go into the correct position.

What instrument do they use to perform the shaving procedure?

The type of equipment used for the IPR producedure may depend on your orthodontist’s preferences and/or the size of the gap that is required. For example, your orthodontist may use a very thin piece of metal ‘sand paper’ that is only rough on one side to make the small gaps (e.g. 0.2mm) but for the larger gaps, they may use a metal grinder with a very thin disk. If a grinding disk is used, the size of the disk used could be smaller than the size of the required gap, since the orthodontists hands will move a bit and you don’t want the gap to be too large.

What is the reason for shaving?

There are multiple possible reasons for stripping/shaving the teeth, for example:

1) To make room for the teeth to move, hopefully without the need for tooth extractions.

2) Not all of our teeth are naturally the same size, just like one foot is usually slightly bigger for most people. The computer program used by Invisalign detects these differences and works out how much the teeth need to be shaved to be closer to being the same size. This makes your teeth look better (more symmetrical) when the treatment is complete.

Ask your orthodontist whether interproximal reduction is required for your treatment plan, and talk to him/her about any concerns you may have.

Invisalign Attachments

During the treatment procedure, some people require “attachments”, which are small blobs of tooth cement (or something similar) that are glued to some of your teeth in order to allow the plastic trays to grip your teeth to twist and pull them.

Will I need attachments?

As part of your initial consultations, impressions are made and photographs taken of your teeth. Your orthodontist works with Invisalign to figure out which teeth need attachments. Make sure you ask about attachments during your consultation so you don’t get a rude shock when you pick up your first Invisalign trays! 😉

How are Invisalign attachments made?

When you go to get your first set of trays, a “stencil” (template) is placed over your teeth with holes for where the attachments need to go. The orthodontist then “spray-paints” the attachments on using the special glue. The stencil makes sure that the attachments go in exactly the right place for your teeth, otherwise your first aligners wouldn’t fit properly. The glue might have a bad taste, but the attachments dry within a minute or so.

Are the attachments visible?

In order to create the attachments, a color “glue” is selected to match your tooth color. So, if you have very white teeth, they use very white glue color and if you have off-white teeth then they select a similar shade of off-white for the glue color.

From the front, Invisalign attachments look like a dots in the middle of the teeth. Looking from the side without your aligners in, they stick out a little bit, although usually you’re wearing your aligners when other people are looking at you.

If you have attachments on your front teeth, your aligners will be more visible than if you did not have any attachments. This is because there are little bubbles in the aligners that correspond to the position of all of your attachments, and these bubbles are slightly visible when the light reflects off the plastic.

Do the attachments hurt?

The “spray-painting” procedure for getting the attachments glued on is usually painless. However, the attachments may cause additional discomfort when taking out the aligners, especially the top set. This is natural due to the tight fit of the aligners – it can seem like you’re trying to “pull out” your teeth when taking off aligners when there are attachments on the teeth. This can be a bit painful, especially at the very start of treatment when you aren’t quite used to the pain yet, and also every 2 weeks when starting a new set of trays when your teeth are especially sensitive. After a few days, there is not as much pain when taking out the new set of aligners, even with attachments, because your teeth have moved and the trays fit more comfortably (i.e. they don’t feel as tight).

Are Invisalign attachments abrasive?

Some patients find that attachments can be a little abrasive if they take out their aligners, depending on the size and shape of the attachments, since the inside of your mouth can get a bit tender where the attachments have been rubbing. However, you’re supposed to be wearing the aligners for almost all of the time, so this isn’t usually a big issue. It’s a bit of an incentive to put the trays back in, anyway, which is a good thing.

Can the attachments fall off?

Yes, the attachments can fall off, although it shouldn’t happen often and may not happen to everyone. Ask your orthodontist/dentist what you should do if an attachment falls off. They will probably tell you to call them the next day to figure out which attachment it was and when you should come back to the office to get it replaced. Depending on which attachment falls off at which time, they can sometimes just re-glue the attachment on at the next regular (6-weekly) check-up. But you should always check with your Invisalign provider if an attachment falls off so your treatment is not delayed unnecessarily.

What happens to the attachments at the end of my treatment?

When your treatment is finished, they “sand down” the attachments to remove them, and then polish your teeth. People shouldn’t be able to tell later that you’ve had attachments on your teeth.

Does food get stuck around the attachments?

This isn’t usually a problem for me personally, however, depending on the size and shape of the attachments (and the configuration of the rest of your teeth), it can be possible for food (e.g. spinach) to sometimes can get stuck around them. Most patients don’t seem to find this to be a bigger problem than getting food stuck between the teeth though. If you’re at an important function or dinner party, it’s probably best to ask someone to confirm that there’s no food caught in your teeth, just in case.

Other issues with Invisalign attachments?

The only additional comment I have is that it seems like the aligners make a very loud noise when I take them out (especially the top ones), and that I strongly suspect this is due to the large number of attachments I have. The plastic makes a few clicking sounds as I take out my top aligners, and there is just one click sound as the bottom aligners snap off around the attachments. I worried at the beginning that I was breaking them, but now I’m more comfortable with them and I don’t worry so much. (I mean, you’ve gotta get them out somehow…)

The reason I find the noise to be a problem is that it makes it very hard to take them out discreetly. Ideally, I would like to be able to quickly slip them out while nobody is looking, for example in a meeting when I know that food is about to be served, but if the room is quiet then there’s no way I can do that without attracting a lot of attention. And attention is the last thing I want while I am clawing away at my teeth trying to get the plastic trays off just before other people are planning to eat!

Invisalign and tooth whitening

You might be wondering whether you could use your Invisalign aligners as tooth whitening trays at the end of your treatment. That way, your beautiful straight teeth will look even better!

Apparently it is sometimes possible to use your last set of Invisalign aligners as tooth whitening trays. This would reduce the price of the tooth whitening procedure because the trays (which would normally have to be custom made to suit your teeth, although generally not quite to the extent of the Invisalign aligners) would not need to be specially made. Check with your Invisalign provider about whether this would be an option for you – some orthodontists even offer free tooth whitening at the end of Invisalign treatment.

How long do I need to keep my Invisalign aligners?

Throughout your treatment process, you’ll go through a whole pile of plastic aligners. If you’re like me, you may be wondering whether you should keep your old aligners.

My orthodontist recommended that I always keep my last aligner, just in case something goes wrong with my Invisalign treatment or I lose my aligners. So I have two plastic cases – one for my current set of aligners (for when I’m eating or brushing my teeth) and one for the old set. My orthodontist said that they will never put me back more than one set, but I like to keep my old ones anyway, just to remember how bad my teeth used to be!

By the way, each aligner is numbered in case you get them mixed up.

You might also like to use your last Invisalign aligner as a tooth whitening tray when you’re done with your treatment.

Can I fast track Invisalign?

Your teeth move into position within the first few days of wearing a new Invisalign aligner. Some people think it’s possible to ‘fast track’ their treatments by wearing each aligner for a few days or a week until it stops being super tight, and then they change to the next aligner.

In most cases, the orthodontists prevent this by giving you only a few aligners at a time, for example 3 aligners to last 6 weeks until the next regular check up. However, if your Invisalign provider gives you all of your trays up front, it’s not a good idea to go through the trays as fast as you can. Don’t forget that when your teeth are shifting with orthodontics, there is stuff going on underneath your teeth (i.e. in the gums) that you can’t necessarily see on the surface. For example, the roots may need time to grow. It’s therefore wise to give your body a chance to do what it needs to do and not force your teeth to move more than they are able to. It’s better to trust the professionals about that!

How long do the aligners need to stay in per day?

Invisalign can only work to straighten your teeth while you are actually wearing your aligners. Therefore, you should obviously try to wear your Invisalign aligners as much as possible. My orthodontist told me that I needed to wear my aligners for at least 22 hours per day, i.e. I could take my aligners out for a maximum of 2 hours per day.

During the first month or so, I followed this instruction very seriously – I timed my meals, wrote down notes on the durations and made sure I was not exceeding the 2 hours per day. Since then, I have been conscious that I should have them in as much as possible, but I don’t let it control my life.

If I have meals with other people then they will tend to be longer than usual, and I will generally excuse myself to the bathroom to make sure there’s no food in my teeth (or brush them) and put in my aligners immediately after the meal. While you are eating, you keep your aligners in your Invisalign case.

Apparently my teeth have been moving according to schedule – so far, all of my 6-weekly checkups have been fine. Remember that any agreement you have with your orthodontist about your treatment duration (and expectations in terms of results) would be dependent on you being ‘complaint’, so it is definitely best to wear them as much as possible.

How to take out Invisalign aligners

Since the Invisalign aligners are supposed to fit like a glove, you might be wondering how to get them off/out of your mouth. The aligners must be a very tight fit for your teeth, first so they stay on, and second so they put adequate pressure on the right teeth at the right time.

I think it is much harder to remove the aligners if you have attachments. In this case, you have to ‘unhook’ the aligners over the attachments in order to pull them off. This can be quite painful during the first few days of wearing a new aligner, for two reasons – first, your teeth have not moved yet, so the aligner is a very tight fit, and second, because your teeth are moving, they are very sensitive.

It takes quite a bit of force to remove the Invisalign aligners during this time. I was quite worried that I would snap my plastic aligners at first, but then I got used to it and realized that they are made of fairly hard plastic. I am quite rough with them now and I have not snapped any of my aligners yet, although they are plastic and so could conceivably break if you are very careless (although I think this is unlikely).

From personal experience, it is very helpful to have longish nails when trying to remove the Invisalign aligners. However, even with long nails, it can be difficult, especially if you have attachments. There is a special tool you can use that is designed for this purpose – something like a plastic hook. I’d definitely recommend getting something like this if you’re getting attachments – the last thing you want is to be sitting at home in a panic because you can’t take them out!

Personally, I don’t enjoy watching people claw away at their teeth to take our their aligners, so I will always walk away if I’m in the presence of others while needing to remove them (or if I am with a good friend I might ask them to look away quickly). Using a tool is a bit more civilized. However, if you don’t have attachments, or if you’re towards the end of your fortnight of wearing your aligners (or your total treatment time in general, i.e. when your teeth are straighter), the aligners usually pop out more easily.

Eating with Invisalign

Many people have the same question about Invisalign:

“Can you eat while wearing Invisalign aligners?”

The short answer is no – Invisalign aligners should be worn as much as possible but must be removed before eating. While you are eating, you keep your aligners in your Invisalign case.

At the start of my Invisalign treatment, I tried to eat a couple of things while keeping my aligners in, especially in the first couple of days of wearing a new set of aligners when it is quite painful to remove them. In summary, there are 5 main problems (in my opinion) with trying to eat while wearing aligners:

1) Inability to chew properly. The aligners generally do not line up correctly to let your teeth chew food the way they would if you were not wearing your aligners. I tried to get around this problem by eating food that crunched very easily (without your teeth needing to connect) and then dissolved in saliva (e.g. cookies and hard sweets), with limited success.

2) Damage to Invisalign. Trying to “chew” while wearing aligners puts strange stress on them – you could grind down the surface of them and the aligners could also bend. (Note that this would be while really abusing them – they usually do not bend at all while wearing them the way you should!) The last thing I needed was for my teeth to move in a strange way because I had broken the rules! (Plus, I assume that we would be expected to pay for new aligners to be made in the case of such non-compliance.)

3) The mess. I had no idea how much the food would stick to the aligners before I tried it. Let’s just say that I’m glad that I was staying home all day on the day I got silly enough to try it 🙂 Not only did it look terrible (especially chocolate cookies – NOT a good look!), but it took much longer to clean them than it should have. Apparently the aligners can be permanently stained with some foods too, although luckily this didn’t happen to me.

4) Less taste. I wasn’t really expecting this before I tried it, but food was far less enjoyable to eat while trying to eat with them in than it should have been – the taste was dampened. I’m pretty sure that we don’t have any taste-buds in our teeth so I have no idea why this is, but it’s something I observed so I’m reporting it here.

5) Tooth decay. Another reason why the recommend against trying to eat while wearing aligners is that you risk decay from the sugar in the foods.

UDPATE: Since writing this post, I’ve learned of another possible disadvantage and therefore reason to avoid eating with Invisalign aligners in your mouth:

6) Possible bite issues. When you bite down hard while wearing your aligners, e.g. when chewing, you are putting pressure on some of your teeth. While the plastic of the Invisalign aligners is relatively thin, it still needs to be thick and rigid enough to do its job. At the places where your teeth connect when you chew, there are 2 layers of the plastic. I heard from an orthodontist that it can sometimes be possible for this pressure to push some of your teeth back inside your gums a bit (i.e. either up or down) so that the end result when you take out your aligners is that there is a small gap where your teeth used to connect. This gap means that your chewing is less efficient when you finally get your Invisalign off. I was told that a very small gap caused in this way may naturally correct itself after treatment, but I wasn’t given any guarantees about it and I figure it’s better to be safe than sorry!

Does wearing the aligners change the way you eat?

Due to the pain associated with taking out the aligners, and the annoyance of having to make sure your teeth are relatively clean before replacing them, and not being allowed to have the aligners out for much time during the day, my eating habits have definitely changed as a result of having Invisalign. I used to “graze” throughout the day but now I find that I try to eat 3 bigger meals. This is not really good if you are trying to lose weight.

I also find myself eating junk food (for example, chocolate) after such meals when I do not really feel like it, just because I might feel like it later and I know it’s harder to have it later than have it now. Yes, I know that sounds pretty crazy but it does happen, quite a bit.

This phenomenon of over-eating was much worse at the start of my treatment, before I got comfortable with taking out my aligners quickly and while I was very conscientious with not having my aligners out of my mouth for more than 2 hours every day. However, I still find that it is bad for a few days every 2 weeks when I get new aligners, while they are tight and it hurts a lot to take them out.

What can I eat and drink after I remove the aligners?

If you take out your aligners, you can eat and drink anything. During the first few days of wearing a new set of aligners your teeth will be quite sensitive so it might be painful to crunch hard things, and near impossible to eat apples, but that is only for a few days every 2 weeks.

Drinking with Invisalign

Can you drink water while wearing aligners?

Yes, you can drink cold and room temperature water while wearing aligners. However, drinking hot water is not recommended because it may affect (i.e. melt) the plastic aligners.

Can you drink tea, coffee, or other hot drinks like soups while wearing aligners?

No, it is recommended that aligners are removed before drinking tea and coffee – the hot water may affect (i.e. melt) the plastic aligners. However, I sometimes have some herbal tea (without sugar) with my aligners in, although I leave the cup sitting for quite a while to make sure the liquid is not too warm before drinking it.

Can you drink alcohol or other cool drinks such as fruit juices while wearing aligners?

I was told to avoid drinking anything but water while wearing aligners, even if the liquid is not hot, primarily for two reasons. First, these liquids make the aligners dirty – a build up can form on them, which can actually start to look a bit grubby (and you want your aligners to be as “invisible” as possible) and it can also make the aligners smell bad. (Please refer to posts on cleaning for more details about this.) The second reason for avoiding drinking cool drinks other than water while wearing aligners is that the sugar in the drinks could cause your teeth to decay faster than usual (assuming you do not brush your teeth and clean your aligners after drinking).

What can I drink after I remove the aligners?

If you take out your aligners, you can drink anything.

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