The research questions are: 1.) To evaluate quantitatively the overall NaCh and Nav 1.3, 1.6, 1.7, 1.8 1.9 isoform expressions in nerves of normal teeth as compared to diseased teeth 2.) To evaluate quantitatively hot/cold VR1 and CMR1 receptor expression in nerves of normal teeth as compared to the nerves in the modality-specific pain groups of diseased teeth 3.) To investigate the ultrastructural localization of NaCh isoforms in different fiber types and at sites that may be involved in pain generation.