Dental Impressions

Dental impressions are molds of your teeth and surrounding oral tissues. Dentists use them to create a replica of your mouth, determine how your teeth fit together and plan treatments. They can be made with soft putty — often alginate or polyvinyl siloxane (PVS) — or a digital scanner.

Impressions are used to make:

• Restorative treatments: Crowns, bridges, veneers, dentures, implants
• Orthodontic appliances: Clear aligners, retainers
• Other custom appliances: Mouth guards, teeth-whitening trays, sleep apnea appliances, fluoride carriers

Types of dental impressions

There are three main kinds:

• Preliminary: Used early in treatment planning for study models
• Final: Used to create your dental appliance or final restoration
• Bite registration: Shows how your top and bottom teeth fit together

How are dental impressions taken?

Dentists use either traditional putty or digital tools.

• Traditional (putty-based) impressions: A soft material goes into a tray, which is pressed onto your teeth. After it hardens, the tray is removed and sent to a lab. There, technicians make a model of your mouth.
• Digital impressions with a scanner: A dentist uses a small wand to take intraoral pictures of your teeth. A computer combines the images into a 3D model. These are sent electronically to a lab.

Here’s a quick comparison:

Do dental impressions hurt?

Dental impressions don’t hurt, but the material can feel uncomfortable or trigger a gag reflex for some people. If you’re concerned, let your dentist know. They can recommend ways to make it easier.