The human tooth pulp has many nerve fibers and is a common source of pain. This study examines nerve fibers within normal and painful samples and identifies changes that can contribute to the generation of pain.

The human tooth pulp is a rich source of pain fibers and is a common site of pathology that is often accompanied by spontaneous and stimulus-induced lingering pain. A common treatment modality includes the extraction of the offending tooth diagnosed with irreversible pulpitis. Extracted teeth represent an abundant source of normal and diseased human nociceptors and the evaluation of these tissues represents a powerful model to study human pain mechanisms since the character of pain, pain levels, and response to stimuli can be documented prior to extraction.

The overall objective of this study is to correlate changes in the expression of Sodium Channels (NaCh) with clinical responses to hot and cold thermal stimuli, and the expression of the associated receptors/transducers responsible for receiving that stimulus in extracted teeth with severe and spontaneous pain. Teeth requiring extraction in the clinical setting will be used for this study.

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.

Inclusion Criteria:

• individuals 16-80 years old
• normal third molar(wisdom)teeth
• painful, diseased teeth requiring extraction

Exclusion Criteria:

• individuals under age 16 or above age 80
• pregnant females
• prisoners
• nonvital painful teeth

Healthy patients presenting to the dental clinic with an indication for extraction of their normal third molar(wisdom) teeth or diseased teeth that are associated with pain.