IADR Abstract Archives
Evaluating Indolamine 2, 3 Dioxygenase’s (IDO) Role in Irreversible Pulpitis
Objectives: Pulpal disease involves both acute inflammation and often neurogenic inflammation driven by neuropeptide release. Systemically it is known that IDO can protect against, or potentiate, neurogenic changes associated with this (central) sensitisation. There are, however, no quantifiable data on any role IDO may play in pulpal inflammation. The objectives of this human study were to:
1. Compare IDO activity between healthy control teeth and irreversibly pulpitic teeth
2. Examine IDO activity related to pain intensity and duration of pain.
Methods: Healthy (orthodontic extraction of virginal teeth) and irreversibly pulpitic teeth were collected from those extracted at Newcastle Dental Hospital following ethical approval. No patient identifiable data was recorded, but the number of days’ pain and the severity of pain (out of 10) on the day of extraction were documented to indicate intensity and duration. Pulp tissue was removed via sectioning post-extraction. The samples then had IDO activity measured by high performance liquid chromatography.
Results: Results revealed that healthy samples (n=27) had low levels of IDO activity (3.19 ± 0.77 pmol/hr/mg of tissue) while painful samples (n=26) had a higher level (8.00 ± 1.6 pmol/hr/mg) which was significantly higher than the healthy samples, t (51) = -2.7375; p=0.0085; 95% CI of difference -8.3480, -1.2840). In painful teeth the mean duration of pain was 10 days (+/-17.8) and the mean intensity of pain on a numerical rating scale was 8.04 (+/-2.20). There was no correlation between pain duration (r= 0.0854, p>0.05) or pain intensity (r= 0.2433, p>0.05) and the level of IDO activity.
Conclusions: The results suggest a strong link between pulpitic teeth and the level of IDO activity. At present this link does not appear to be affected by pain severity or duration, but IDO undoubtedly plays a role within pulpal inflammation and with further research may represent an important target in the management of acute inflammatory and possibly chronic neuropathic pain following deafferentation.
1. Compare IDO activity between healthy control teeth and irreversibly pulpitic teeth
2. Examine IDO activity related to pain intensity and duration of pain.
Methods: Healthy (orthodontic extraction of virginal teeth) and irreversibly pulpitic teeth were collected from those extracted at Newcastle Dental Hospital following ethical approval. No patient identifiable data was recorded, but the number of days’ pain and the severity of pain (out of 10) on the day of extraction were documented to indicate intensity and duration. Pulp tissue was removed via sectioning post-extraction. The samples then had IDO activity measured by high performance liquid chromatography.
Results: Results revealed that healthy samples (n=27) had low levels of IDO activity (3.19 ± 0.77 pmol/hr/mg of tissue) while painful samples (n=26) had a higher level (8.00 ± 1.6 pmol/hr/mg) which was significantly higher than the healthy samples, t (51) = -2.7375; p=0.0085; 95% CI of difference -8.3480, -1.2840). In painful teeth the mean duration of pain was 10 days (+/-17.8) and the mean intensity of pain on a numerical rating scale was 8.04 (+/-2.20). There was no correlation between pain duration (r= 0.0854, p>0.05) or pain intensity (r= 0.2433, p>0.05) and the level of IDO activity.
Conclusions: The results suggest a strong link between pulpitic teeth and the level of IDO activity. At present this link does not appear to be affected by pain severity or duration, but IDO undoubtedly plays a role within pulpal inflammation and with further research may represent an important target in the management of acute inflammatory and possibly chronic neuropathic pain following deafferentation.