UCSF

It is challenging to identify demineralized areas of root lesions due to cervical erosion, calculus formation, and heavy staining of dentin. We have found that root caries can be imaged with extremely high contrast at short wavelength IR (SWIR) wavelengths beyond 1500-nm. Lasers are well suited for the selective removal of caries lesions from tooth surfaces. A CO₂ laser operating at a wavelength of 9.3-μm was combined with a thulium-doped fiber laser operating at 1880-nm for the selective removal of root caries lesions from extracted teeth. Serial SWIR reflectance images at 1880-nm were used to guide the CO₂ laser for image-guided laser ablation. Cross polarization optical coherence tomography (CP-OCT) was used to assess the initial depth of the lesions before removal and assess the volume of sound and demineralized tissue removed by the CO₂ laser. With this image-guided approach, we believe we can achieve highly selective lesion removal and minimal damage to surrounding sound tissues.