Where to begin, well to me aligners seem to be the ultimate turnkey operation……you take an impression, no its simpler that, you take a scan (people seem to think taking a scan is a ‘no brainer’ thing to do… its not) and send it way… the ‘system’ then produces a treatment plan for you… and all you do is serve up the aligners and collect the cash… you don’t even need to see the patient what with the trend to move to remote monitoring…. they stress how safe it is… you don’t need to see the dodgy dirty dentist what with all those aerosols and covid….patients pay their money, collect the aligners and simply return for retainers… hmmmm…in fact theres companies already out there missing out the dentist!
However, like most things, if something is too good to be true….
So… lets take a dip into aligners and see if they are really another form of plaque on the teeth… ‘plastic plaque’.
Aligners have been around for many, many years. I think it was back in 80s when Jack Sheridan wrote his book and we were pouring plaster models, sectioning the teeth and putting them in wax to create the incremental movements for our DIY aligners. Then in the the late 90’s Invisalign came along with the 3D printing of the models and used the very clever idea of ‘direct to market’ marketing … so now the patient comes in knowing what they need before even seeing a clinician.
At that time we were, how can I put it, conservative with the type of tooth movements we prescribed with aligners. Simple tipping and rotations.
So whats changed since? Well, the prescribed tooth movements for one. Movements we normally reserve for fixed appliances (like intrusion). But don’t forget, for every action theres a reaction. So intruding teeth will simply ping off the aligner as thats the reciprocal force and equilibrium must be achieved. But, ‘attachments’ come along. Nice blocks of composite bonded to the teeth. But hang on, these are ‘special’. FEM has designed them. Finite Element Model analysis calculates the force and so ensures the delivery of the movements.
And advances in AI blended with FEM ensure that the treatment plan will work! Really ? Don’t you just love it when someone turns to you and say’s “the computer says” . Grrrrrrrr Muppets...
Now one of the main ‘problems’ is that the aligner is simply pressure formed (forget vacuum forming - the aligners are too ‘baggy’ for my liking) and the plastic is thinned over the model. We can’t increase ‘the wire size’ like in a fixed appliance. Well, we can now. With Giphy producing a resin for ‘direct printing’ of the aligner, no models are needed. It will be possible to ‘enhance’ or ‘thicken’ certain areas of the aligner to re-enforce or deliver more force in that area. Sounds promising. Now I m getting excited. And, the move to ‘in office’ fabrication will save me thousands ..oh yes, now we’re cooking….(but oh my… they don’t tell you of the thousands of hours lost in learning the software, the intricacies of 3D printing etc. etc…. so be warned).
Back to pressure forming, another good bit of news is that the plastics has also improved with the advent of laminate materials e.g. Zendura FLX and CA PRO + so they have less water absorption and have better “resilience’ and hence force delivery.
So, overall, I d saY aligners are advancing and are far better than before. However, a solution to every malocclusion as many would suggest, I think not.
And the thing I haven’t mentioned is the elephant in the room … compliance…and we tip out hat to ‘House’…. as he says…’everyone lies’… do they really were them 20+ hours a day…. and can we really torque the teeth…. hmmm there must be an alternative… well there is … for truly invisible brace with minimal compliance issues its lingual orthodontics… don’t wish for fewer problems as the saying goes….
So, are we there yet? No, more brushing is required to polish the plastic plaque before its the solution to every malocclusion. Fantastic, not yet…..
ps Shout out to Ehsan for the photo
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