Superluminescent LED allows early dental diagnosis
A medical imaging technique that uses an InP-based superluminescent LED (SLED) is being used by dentists to detect teeth in the early stages of disease.
The US firm Lantis Laser has developed an optical coherence tomography (OCT) imaging instrument based around an SLED supplied by the Singapore-based company DenseLight Semiconductors.
According to dentists that have trialled the technique at the University of Pennsylvania (UPenn) School of Dentistry, OCT can detect oral problems before a conventional X-ray image can.
This is because the spatial resolution of the three-dimensional images produced by OCT is ten times better than an X-ray. The result could be earlier, less-damaging treatment of diseased teeth.
One reason for this is that X-ray detection of tooth decay depends on a variation in material density, which is a sign that damage has already been done, whereas OCT relies on more subtle variations in optical characteristics.
OCT requires a broadband light source, and Denselight's Sunil Phatak believes that it is the particularly "clean" power output of his company's SLEDs that benefits the dentists.
"Simply boosting the output power of an SLED by brute force is no longer acceptable," said Phatak. "Customers keep clamoring for "˜clean' power "“ useful optical power with low coherence noise, high polarization and wider spectral bandwidth."
Denselight's SLEDs produce over 50 mW output, with a spectral width of more than 70 nm.
"We have tried several broadband light sources. The Denselight 1310 nm SLED is clearly superior and performs well consistently in generating exceptionally clear images," said UPenn dentist Linda Otis.
Lantis Laser will now look to commercialize the technique and gain clearance from the Food and Drug Administration, the regulating body in the US. "OCT has a very definite function in dentistry," said Lantis's Stan Baron. "Lantis Laser is ready to embark on developing pre-production prototypes and then address market introduction in 2006."
