Nondestructive monitoring of the repair of enamel artificial lesions by an acidic remineralization model using polarization-sensitive optical coherence tomography

Objectives. It is difficult to completely remineralize carious lesions because diffusion into the interior of the lesion is inhibited as new mineral is deposited in the outermost layers. In previous remineralization studies employing polarization sensitive optical coherence tomography (PS-OCT), two models of remineralization were employed and in both models there was preferential deposition of mineral in the outer most layer. In this study we attempted to remineralize the entire lesion using an acidic remineralization model and demonstrate that this remineralization can be monitored using PS-OCT. Methods. Artificial lesions approximately 100-150 mu m in-depth were exposed to an acidic remineralization regimen and the integrated reflectivity from the lesions was measured before and after remineralization using PS-OCT. Results. Automated integration routines worked well for assessing the integrated reflectivity for the lesion areas after remineralization. Although there was a high degree of remineralization, there was still incomplete remineralization of the body of the lesion. Conclusion. This study demonstrated that PS-OCT can be used to non-destructively measure changes in lesion structure and severity upon exposure to an acidic remineralization model. This study also demonstrated that automated algorithms can be used to assess the lesion severity even with the presence of a weakly reflective surface zone. (C) 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.