The effects of pulsed photothermal radiometry (PPTR) using a thermal camera on the optical and thermal properties of biological materials are investigated. Changing the pulse repetition frequency of the laser pulses affects the penetration depth of the laser, which can provide three-dimensional (3D) images in arbitrary planes and allow imaging deep within a solid tissue. A 3D heat conduction formulation that uses 3D optical diffusion is developed to derive a turbid frequency-domain PPTR (FDPPTR) model. The proposed model may be useful for non-contact, non-invasive, in situ evaluation for the depth profilometric imaging capabilities. The model is applied for monitoring carious and artificial subsurface lesions in human teeth.