The five things you need to know about aligners & Invisalign

The five things you need to know about Invisalign

I started my treating my first Invisalign patient in 2008. Prior to this, as a cosmetic dentist, if my patients didn’t like their smile I could only really offer them two solutions – braces or veneers. The majority of my patients weren’t too keen on braces, and veneers always seemed such an invasive way of getting things looking good. Did I really want to be drilling teeth down in a person who is in their 20’s and 30s? Not really – the healthiest tooth is one that has never had to be touched by a dentist – and besides, I preferred to work with what nature had already provided. 

12 years later, and over a thousand cases under my belt, I can say that the technology has progressed so much over that time that I can now take on clients that I would never have believed we would be able to be treated with Invisalign all those years ago. But equally, over the years I have found the same questions popping up again and again both during initial client consultations, and also reading clear aligner forums where people have commented on things that they had wish been explained more clearly to them before they started the journey.

So in this post I aim to go over what you need to know about achieving a great smile with clear aligners.

All aligners are the same right?


Not even close. 

Over the years I have tried a few other systems apart from Invisalign. Sometimes out of curiosity, sometimes because the manufacturer claimed it was the next big thing, or that it was cheaper, or maybe they just had really slick marketing (and I apologise to all the Dental Assistants I have trialed them on over the years!). 

I’ll discuss some of the differences further on in this post but lets talk about one of the main ones – what the aligner is made from. 

In the old days we used to use a material called EX40. It was rubbish – but it was all we had. The material was incredibly rigid which made learning to take the aligners in and out much more difficult. They were also much more painful to wear – because they were so rigid, patients would experience a huge amount of pressure (and therefore pain) for the first 48hours or so. They also weren’t great at keeping the teeth moving for the whole of the 2week cycle that they were being worn because they fatigued too quickly.

These days, Invisalign uses its patented SmartTrack material which has been such an improvement. The material is a lot more flexible and therefore more comfortable and makes the aligners so much easier to take in and out. The best part though, is that the aligners produce a lower force for a longer period of time – that not only means less pain for the patient, but the teeth are moving for most of the time that set is being worn.  More comfortable, more predictable, shorter treatment times.

You can still get EX40 though – Invisalign for a while had a nice side hustle selling their old material to other aligner companies!



When you are moving teeth you need the aligner to lock on to the teeth tightly, and you need all the forces that you are generating to be applied to each tooth at the right angle at the right time. If you are just pushing a tooth backwards or forwards that is easily accomplished by the aligner material itself. Once you start trying to untwist a tooth, or bring it up, or down, its an entirely different story. With these more complex movements it is easy for the tooth to “slip” in the aligner and not move – as you progress through the aligners that particular tooth will just fall further and further behind. At that point you are wearing aligners – but you are no closer to getting that smile you always wanted.

That is where attachments come in.

Attachments are small buttons of filling material that are placed on the surface of a tooth. They are easy enough to put on – no drilling or anesthetic needed. The challenge is that they can make the aligners more visible so we try and keep them off the front teeth wherever we can. 

So there are three types of attachment systems that aligner systems use. 

1. No attachments at all. Sounds great – but you have to ask yourself was your goal to wear aligners or was your goal to have straight teeth?  For simple movements though no attachments are required – which is it what some of the direct to customer systems are banking on (you know, the ones where you don’t actually ever see a dentist and the aligners are sent to you at home). 

2. Old style attachments. These are buttons that have the sole purpose of giving the aligner something to click on to lock the aligner into place.

3. Optimised attachments. Once again a product of the Invisalign R&D department – and once again something that has  a mind boggling amount of patents attached to them! With optimised attachments the software custom designs each individual attachment on a tooth by tooth basis to ensure that forces are applied to each tooth are at the perfect angle to get the tooth moving. I’m not an Invisalign scientist but I do know that when Invisalign transitioned from the old style attachments to the new generation attachments by patients treatment times dropped by a third almost overnight!

Love or hate them – attachments get you to the finish line quicker.


It's all about space

If you have crowded teeth we need to find the space to get them lining up nicely.

One option of course is to simply take teeth out. I’m not generally a big fan of that – and not surprisingly neither are my patients! It is always an option but one that is generally avoided wherever we possibly can (and for the vast majority of Invisalign cases I don’t perform any extractions at all)

Assuming we aren’t going to take out teeth there are three other main ways we gain space:

  1. Expansion. When looking at someone with crowding we often find that their middle and back teeth are pulled in a long way resulting in a narrow smile where we only get to see the front 4-6 teeth when someone is smiling. In expanding these teeth out to where they should be we not only create a more pleasing smile, but we also create room to resolve any crowding of the front teeth.
  2. Recontouring. This is where we polish away a (very!) small amount of enamel from in between the teeth to create a little more room. This is especially useful when the shapes of the teeth mean they don’t sit together very well.
  3. Proclining / TIlting the teeth. This is where you tip the front teeth outwards which creates a bit more room. You have to be a little careful that you don’t tilt the teeth out too much as it can lead to a bucked tooth appearance!

When seeing a dentist or orthodontist we will often use a combination of all three to achieve the best possible result. If you have ordered a DIY kit (where a company sends you you the aligners without seeing a dentist) then usually you are limited to option 3.


One & Done?......Refinements

So you’ve got your aligners – all you need to do is where them and once you get to the last one everything is going to look perfect right?

Well maybe……..but not usually.

All people are different, and correspondingly all teeth are different. We often find that with some patients their teeth move quickly and efficiently while in others the teeth are a little more stubborn. It is not uncommon to find at the end of a series of aligners that most of the teeth have moved really well while the a few others have been a little more stubborn and need a few more aligners made to get them to the finish line.

That is where refinements come in and all they are additional aligners that are made to get things looking as perfect as possible.

Some systems allow for refinements and some do not. Equally some dentists charge for additional rounds of aligners while for others it is included in the fee paid at the start. I have always included refinements as part of the treatment fee – after all what it is the point of getting 80% of the result you wanted?

Before going ahead with any aligner treatment make sure that you confirm that additional aligners can be made if the teeth do not completely straighten during the first round and also any costs that are associated with getting these extra aligners made. 


One & Done?......Refinements

A simple one this one.

Is your goal to wear aligners……or is your goal to have a great smile? 

If it is a great smile you are after you need to be aware that correcting any crowding will be a great step. But have you thought about the color of the teeth? What about the shape? I often find that over the years patients will have chipped and worn some of the front teeth. While not that noticeable when everything is crowded, as soon as you straighten everything up they can become quite obvious.

I have written a post on this previously:

The Last 5%