Selective ablation of dental caries using coaxial Co 2 (9.3-μm) and near-IR (1880-nm) lasers.

OBJECTIVE: The purpose of this study was to determine the feasibility of image-guided laser ablation of demineralization from tooth occlusal surfaces using coaxial near-infrared (NIR) and CO2 lasers.

MATERIALS AND METHODS: 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 simulated occlusal caries lesions from 10 tooth samples. Serial NIR reflectance images at 1880-nm were used to guide the CO2 laser for image-guided laser ablation. Polarization-sensitive optical coherence tomography (PS-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.

RESULTS: PS-OCT scans indicated that roughly ∼99% of the lesion was removed by image-guided laser ablation. A mean volume of 0.191-mm3 or 11.9-μm/voxel of excess enamel was removed during lesion removal.

CONCLUSION: A co-aligned NIR/CO2 laser scanning system has great potential for the highly selective removal of dental decay (demineralization). Lasers Surg. Med. © 2018 Wiley Periodicals, Inc.