Patent ID: 7139068

Claim:
A method for determining optical characteristics of a dental object comprising the steps of: positioning a probe substantially in contact with the object, wherein the probe provides light to the object from one or more light sources and receives light from the object through one or more light receivers, wherein received light is transmitted to a measurement device for measurement, wherein the one or more light sources and the one or more light receivers have numerical apertures and positioning relative to each other to define at least first and second light source-light receiver pairs having first and second critical heights, respectively, below which light reflected from a surface of the object is not transmitted to the measurement device for measurement, wherein the first critical height is different from the second height; measuring optical properties of light received and transmitted to the measurement device, wherein a first measurement is taken based on the first light source-light receiver pair having the first critical height and a second measurement is taken based on the second light source-light receiver pair having the second critical height; and determining optical characteristics of the object based on the first and second measurements, wherein the optical characteristics of the object include optical characteristics of one or more subsurface characteristics of the object.