Sodium Channel Expression in Human Teeth

• Sodium Channel (NaCh) expression in nerves of normal teeth compared to diseased teeth. [ Time Frame: Immediately following extration of the tooth. ] [ Designated as safety issue: No ]
  Ex vivo lab bench study utilizing extracted human teeth.
  
  

• Vanilloid receptor subtype-1 (VR1) and cold-and menthol-sensative receptor-1(CMR1) expression in normal vs diseased teeth. [ Time Frame: Immediately following extraction of tooth. ] [ Designated as safety issue: No ]
  Ex vivo bench lab study utilizing extracted human teeth.
  
  

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.