Study On The Anti-inflammatory Effect Of Local Application Of Indomethacin On Rat Dental Pulpal Trauma

Purpose: Trauma and procedures in conservative dentistry can often result in pulpal injury, leading to inflammatory response of pulp. Prostaglandin is an important proinflammatory mediator. The present study investigated the inhibitory effects of local application of indomethacin on the production of prostaglandins in the experimentally traumatized dental pulp of rats and sought to determine the optimal dose of indomethacin , in order to provide a novel anti-inflammation and analgesia therapy for pulpitis in the early stage. Methods: One hundred and sixty sterile SD rats were randomly divided into six groups: 10 in the normal control group, 30 in the untreated model group, 30 in the ZOE-treated group, and 90 in the indomethacin-treated group. The indomethacin- treated group was subdivided into three groups according to the high ,middle, and low dose of indomethacin used, with 30 rats in each. Except the control group, the other groups were further divided into three subgroups according to the time points observed after pulp trauma, which were the 2nd,6th and 12th hour. I-Listopathologic study (H.E staining) was used to observe the morphologic changes of pulpal tissues. Radioimmunoassay(RIA) was used to measure the kinetic changes of the levels of PGE2 ,6-keto-PGF1a (stable metabolite of PGI2 )and TXB2 (stable metabolite of TXB2) of pulpal tissues. Results: Dilated blood vessel , hyperemia, various degrees of neutrophil adhesion to the blood vessel wall and infiltration were observed in the untreated groups, demonstrating severe inflammatory responses in the traumatic pulps. Moderate 3 hyperemia responses could be observed in the ZOE-treated subgroup , high dose and middle dose of indomethacin-treated subgroups while mild hyperemia was observed in the low dose of indomethacin-treated subgroups. The levels of PGE2, 6- keto-PGF1a and TXB2 in the untreated subgroups were higher than that of the control group(pO.O5). The results suggested that ZOE and indomethacin could effectively block the cyclo-oxygenase pathway and reduce the production of prostaglandins. At the time point of 2 hour after trauma, each dose of indomethacin was more effective in reducing the level of PGE2 than ZOE. At the time point of 6 hour after trauma, middle and low doses of indomethacin were more effective in reducing the level of.6-keto-PGF1a than ZOE(p