2.1 Tooth Samples and MicroCT
Teeth were collected from patients in the San Francisco Bay area with
approval from the UCSF Committee on Human Research. The teeth were
sterilized using gamma radiation and stored in 0.1% thymol solution to
maintain tissue hydration and prevent bacterial growth.
The teeth were imaged using Microcomputed X-ray tomography (microCT)
with a 10 µm resolution. A Scanco microCT 50 from Scanco USA (Wayne,
PA) was used to acquire the images. MicroCT images of 120 teeth were
examined and ten teeth with occlusal lesions chosen with distinct
surface zones of mineral content approaching that off sound enamel were
selected and designated as arrested while ten teeth were chosen for
which the surface zones were not highly mineralized and those were
designated as active lesions. Often lesions are present on the tooth
that are only partially arrested and have both active and arrested areas
[9].