Viability of imaging structures inside human dentin using dental transillumination

摘要

Dental Transillumination (DT) is a technique for imaging internal structures of teeth by detecting infrared radiation transmitted throughout the specimens. It was successfully used to detect caries even considering dental enamel and dentin scatter infrared radiation strongly. Literature reports enamel's scattering coefficient is 10 to 30 times lower than dentin; this explain why DT is useful for imaging pathologies in dental enamel, but does not disable its using for imaging dental structures or pathologies inside the dentin. There was no conclusive data in the literature about the limitations of using DT to access biomedical information of dentin. The goal in this study was to present an application of DT to imaging internal structures of dentin. Slices of tooth were confectioned varying the thickness of groups from 0.5 mm up to 2,5 mm. For imaging a FPA InGaAs camera Xeva 1.7-320 (900-1700 nm; Xenics, Inc., Belgium) and a 3W lamp-based broadband light source (Ocean Optics, Inc., USA) was used; bandpass optical filters at 1000±10 nm, 1100±10 nm, 1200±10 nm and 1300±50 nm spectral region were also applied to spectral selection. Images were captured for different camera exposure times and finally a computational processing was applied. The best results revealed the viability to imaging dentin tissue with thickness up to 2,5 mm without a filter (900-1700nm spectral range). After these results a pilot experiment of using DT to detect the pulp chamber of an incisive human tooth was made. New data showed the viability to imaging the pulp chamber of specimen.