Intraoral Scanner

Overview

An intraoral scanner is the pen-shaped wand a dentist sweeps around the mouth to capture a colour 3D model of the teeth and gums, replacing the tray of putty impression material. The model drops straight into design software for a crown, aligner or implant guide, so the same scan that records the case also drives the Dental Milling Machine that mills it.

Everything optical lives in the Optical Handpiece. An CMOS Image Sensor looks out through a Lens Assembly and a Folding Tip Mirror in the tip, while the Structured-Light Projector casts a known pattern of light onto the tooth. The way that pattern bends across the surface tells the scanner the depth at every point. Because a mouth is warm and wet, the Anti-Fog Mirror Heater heater keeps the tip mirror above dew point so breath cannot fog the view. The Processing Board board stitches each captured frame onto the growing model in real time and streams it down the Cabling & Connector to the Cart & Touchscreen, where the clinician watches the arch fill in on the touchscreen.

The wand never touches a patient directly: an autoclavable sleeve from Sleeve Tips covers the head and is swapped between patients.

How it works

Scanning is structured-light triangulation. The Pattern Laser Diode and Illumination LED in the Structured-Light Projector send light through the Pattern-Forming Optic, which turns it into a calibrated grid that the Folding Tip Mirror folds onto the teeth. The CMOS Image Sensor views that same patch from a slightly different angle through the Lens Assembly; because the projector-to-camera geometry is fixed by the Optical Bench Mount, the apparent shift of each projected feature gives its distance. One exposure yields one depth frame.

The Processing Board board runs the wand. An Microcontroller keeps the sensor and projector in lockstep so each frame is exposed under a known pattern, and an Compute SoC Module does the heavy work: it finds overlapping geometry between consecutive frames and registers them into one coordinate system, the same way panorama software aligns photos, except in three dimensions and at video rate. Colour comes from a separate white-LED exposure that paints texture onto the geometry. The finished mesh travels up the Tether Cable through the Connector to the cart.

Two practical problems shape the design. Fog is one: the Mirror Thermistor and Heating Element in the Anti-Fog Mirror Heater hold the Folding Tip Mirror warm so condensation never forms. Cross-contamination is the other: the Tip Optical Window on each Tip Body takes the patient contact, then goes to the autoclave while the optics stay clean. The Workstation Touchscreen on the Cart & Touchscreen shows the live model so the operator can see and fill any holes before ending the scan.