Whitening Trays

During my time as a dental assistant, I used some advanced imaging techniques to take pictures of people's smiles. One of these people was myself, and I used this power to make my teeth nice and sparkly. By using a CBCT machine and taking impressions, I made the whitening trays shown in the pictures. 

CBCT, or cone beam computed tomography, is what I used to take a high-resolution picture of my head. It's like a traditional X-ray, but a rotating arm allows multiple images to be taken from different angles. 

Photo of myself using the CBCT machine

Once the CBCT scan was complete, the images were assembled together by the machine’s software into a detailed 3D model of my teeth and gums.

As fun as it would’ve been to 3D print a whitening tray directly from that model, its real purpose was diagnostic, confirming that both my teeth and gums were healthy enough for whitening. Happily, they were in great shape.

Working model

The process really began with making a 3D model of my teeth. Initially, I created an impression of my teeth by biting into an alginate mix and remaining still for 3 minutes. Alginate is derived from brown seaweed, and when mixed with water, it makes a tan sludgy substance perfect for making impressions. Besides being cost-effective and nontoxic, it's hydrophilic, so it works well in the presence of saliva. 

Then, I poured dental plaster into the mold, creating the working model seen above.

Thermoforming plastic

After this, I heated a thin sheet of thermoforming plastic and placed it over the working model. Using a vacuum sealer, it was molded over the model of my teeth.

Once it cooled, I trimmed the tray with a pair of scissors. I focused on making sure the tray fit comfortably, which meant going just over the teeth - not too far onto the gums. 

Voila! Besides making my teeth shiny, I learned an advanced imaging technique and a little bit of chemistry.