Abstract

Selective caries treatment has been anticipated as an essential application of dentistry. In clinic, some lasers have already realized the optical drilling of dental hard tissue. However, conventional lasers lack the selectivity, and still depend on the dentist’s ability. Based on the absorption property of carious dentin, 6 Pm wavelength range shows specific absorptions and promising characteristics for excavation. The objective of this study is to develop a selective excavation of carious dentin by using the laser ablation with 6 Pm wavelength range. A mid-infrared tunable pulsed laser was obtained by difference-frequency generation technique. The wavelength was tuned around the absorption bands called amide 1 and amide 2. In the wavelength range from 5.75 to 6.60 Pm, the difference of ablation depth between demineralized and normal dentin was observed. The wavelength at 6.02 Pm and the average power density of 15 W/cm², demineralized dentin was removed selectively with less-invasive effect on normal dentin. The wavelength at 6.42 Pm required the increase of average power density, but also showed the possibility of selective ablation. This study provided a valuable insight into a wavelength choice for a novel dental laser device under development for minimal intervention dentistry.

© 2011 OSA/SPIE