How Does the Invisalign Process Work?
The first step to starting Invisalign treatment is to get an exam at our office. The exam is free. At the exam we will determine whether or not you are a good candidate for Invisalign treatment. Invisalign is really good at what it does, but there are certain situations where Invisalign will not work very effectively. A key to remember is that Invisalign works for teens and adults. Kids that still have baby teeth, or adult teeth that still have to grow in a lot do not qualify.
Once we determine you are a good candidate for Invisalign, we take records. The records include photographs of your teeth and face, dental impressions of your teeth, and two x-rays. We send those records off to Invisalign with detailed instructions on how I want the teeth to be moved. Invisalign then scans your impressions, so that they have a 3D model of your teeth in their computer. Their technicians will move the teeth step by step in the computer model to their final positions. I then log on and review the movements of the teeth. Typically, they get it pretty close, but I have to instruct them on some fine point details of how I want the teeth to be moved. They make the changes, and then I review them again. I usually need to do this a couple of times to get the teeth exactly where I want them. Once I am satisfied, I ask Invisalign to go ahead and make the trays and mail them to our office. It usually takes about 4 weeks from the time of the impressions until we get the trays back to our office. Then you are ready to start straightening your teeth!
The way the system works is you wear a set of Invisalign trays (called aligners) for two weeks at a time. Each tray is manufactured so that the teeth are slightly straighter than the previous tray. The teeth will typically move 1/10mm per tray. So when you put a new tray in, the teeth in the tray are slightly straighter than your teeth are. This puts pressure on your teeth, and over the course of two weeks your teeth will move so that they match the tray.
Most people that get Invisalign treatment have crowded front teeth. So if you think about crowding, there is not enough room for the teeth to fit. We need to make more room somehow and we do this in several ways. On most people, I will have the trays do some expansion of the back teeth. This does several beneficial things. One, it makes more room to correct the crowding in the front. Two, it makes for a broader smile, which also looks better. For a lot of people, we will also bring the front teeth forward slightly. A third way we make more room to correct the crowding is to make some of the teeth slightly skinnier. This process is called interproximal reduction (a fancy way of saying we do a little bit of sanding or filing in between some of the teeth to make a little bit more room). This is not something that you can readily see and it stays well within the enamel of the tooth so that you don’t get sensitivity later.
On a lot of people we also need to use something called ‘attachments’ on the teeth. Attachments are small, tooth colored, bumps of plastic material (composite) that we need to put on some of the teeth. Basically, what they do is to give a handle or gripping point for the aligner to click into place around. They help the aligner stay on better and they also can put pressure on the teeth in the direction we need to straighten them out. Not everyone needs these, but a lot of people do.
Sometimes we will also ask people to wear rubberbands with their aligners. This is very similar to what we would ask a patient to do with traditional braces. We will use these to rotate a particular tooth, or if they are worn from the upper aligner to the lower aligner, they are used to help correct the bite.
I will ask most people to wear their aligners close to full time. A major advantage of the Invisalign system is that you can take them out to eat. We also ask you to take them out to brush and floss and you clean the aligners with a toothbrush at the time you are brushing. Typically, this means you will have your aligners in for about 20 hours a day. If you do not wear your aligners this much, the teeth will not have moved to their final position for that particular tray. When you go on to the next set of trays, they will not fit quite as well. This has a cumulative effect and by the time you get 3 or 4 trays down the line, they will not be fitting well at all.
Most of the time (I would estimate about 70%) we will get finished with your last tray and there will be a few teeth that are still slightly out of position. I tell people this ahead of time, because it is pretty normal. If that is the case, we take a new set of impressions and I have Invisalign make us some more trays to detail things. The process for this is identical to what I described earlier. The new trays will come back in 3-4 weeks and we will continue with straightening your teeth. Invisalign refers to these as refinement trays. There is not an additional fee for this, it is part of the process. Most people need to get 1 set of refinement trays. Invisalign allows us to do this up to 3 times, but in my experience that is very rare.
Once we are done with your final trays, it is time for retainers. Most Invisalign patients chose clear plastic retainers that look like Invisalign trays. Some people choose to get a fixed (permanent) retainer on the inside of their lower front teeth. This is a wire that goes across the inside of your lower front 6 teeth. The choice will be yours as to what kind of retainer we use. I ask most people to wear their retainers full time for 2 months and then we cut back to just while sleeping. Eventually, we get to the point where you are just wearing it a night or two a week. People often ask why we need to use retainers. The simple fact is that nothing about your body remains constant. It all changes as we age and that includes your teeth. Biting and chewing can put a lot of pressure on your teeth, and over time, these forces can move your teeth around.