1. A method of capturing a digital dental image, comprising: illuminating a dental region of interest (ROI) using light sources; capturing reflectance images by receiving light reflected from ROI in narrow wavelength bands; processing captured reflectance images to determine relative tHb and its oxygenation level using at least a wavelength band that includes an isobestic wavelength for absorption coefficients of oxyhemoglobin (HbO 2 ) and deoxyhemoglobin (Hb); identifying selected areas of interest (AOI) within the dental ROI having selected pixel image characteristics of both hemoglobin's total concentration and oxygenation level; and displaying, storing, or transmitting the identified AOI within the dental ROI.