How Teeth Whitening Trays Are Made
Have you ever wondered how your dentist makes those cool little dental trays that you whiten your teeth with? The answer is thermoforming.
Just like a toy manufacturer creates custom fitted moldings from plastic to fit a particular toy shape and design, so it is with the dentist.
Teeth whitening trays that are formed this way are highly effective at whitening your teeth because they strictly adhere to the exact shape of each tooth which ensures maximum exposure to a whitening reagent – teeth whitening gel. The first step in the whole process is the tooth impression.
You’ve experienced it – the doctor (or dental assistant) places a semi runny goop inside an arch-shaped impression tray and then tells you to “open wide.” The doctor then places a massive piece of plastic and pleasant tasting material (alginate) inside your mouth and presses it up against your teeth.
The pleasing taste of the impression material quickly fades, however, as you start to panic at the thought of having this huge foreign object block your airway for 2-5 minutes (which really feels like an hour).
For many people, this is where the gag reflex starts to kick in. You experience an overwhelming sensation that you are going to choke and die. At least it did for me the first time I experienced it (maybe this would be a better tactic to use on terrorists than water boarding).
Nevertheless, just like a mother giving birth is soon delivered from her travail, the doctor removes the impression and says “I think this might do…let’s do your lower teeth now and see how that goes.” And here we go again.
After both tooth impressions are completed they are taken back to the lab which is often right inside your doctor’s office or it is shipped out to an offsite lab for processing.
In the dental lab, the technician pours a stone material (like plaster) in the custom teeth impressions and then a model is formed – for each arch. The stone molds are then trimmed and then placed inside a thermoforming machine.
The thermoforming machine heats up a 4”x4” piece of rubbery plastic which is then vacuumed over the dental mold and then cooled and cut. Once the trays are cut they are sanitized then you can begin the whitening process.
This same process holds true for clear Essix-style retainers and night guards. The only difference is the material used during the thermoforming process. In all, the whole process of lab work takes just a few days.It make take your dentist up to two weeks to receive them from an off site lab.
Despite the unpleasantness of the impression method and the somewhat lengthy procedure of this system, the end result is fantastic and worth the wait.