Visualization of penetration of TiO$_2$ nanoparticles into tooth tissues samples using optical coherence tomography

Penetration of nanoparticles into the tooth tissues is of significant interest in solving the problems, related to the reduction of the tooth sensitivity, enamel strengthening and restoration and cosmetic bleaching. In the present paper we demonstrate the possibility to use optical coherent tomography for visualization of penetration of nanoparticles into the tooth tissues. As a result of longterm treatment of the tooth tissue sample with the suspension of titanium dioxide nanoparticles we observed significant (up to 5 dB) growth of the OCT signal intensity from the depth 300-600 $\mu$m which is an evidence of nanoparticles penetration into the enamel and dentin.