Mouthwash to Deliver Indocyanine Green for Near Infrared Dental Fluorescence Imaging

Dental diseases significantly impact the quality of life and human populations; the current X-ray diagnostic dental imaging method may also bring the potential health risks to humans. This study used human extracted teeth and rats as animal model to test a new near-infrared (NIR) dental fluorescence imaging system with a painless mouthwash for administering indocyanine green (ICG). Our results show that the mouthwash delivery of ICG enables better image contrast than subcutaneous injection at short imaging time (1-10 minutes after ICG administration): for the erupted rat model, in vivo mouthwash (live rat) showed better imaging quality than injection method or ex vivo mouthwash (dead rat); for the unerupted molar, both mouthwash and injection showed the clear dental structures of the unerupted molars through endoscopic imaging; the dosage of mouthwash was at least 10 times lower than injection method. For human teeth, efficient image contrast was obtained in as short as 1 minute of ICG immersion; caries lesions were represented as a bright dot in the NIR windows. Overall, mouthwash serves as a painless and convenient method for administration of ICG; ICG-assisted NIR mouthwash dental imaging provides a low-cost and safe dental imaging tool for the diagnosis of dental diseases.