RT-qPCR study of COX-1 and -2 genes in oral surgical model comparing single-dose preemptive ibuprofen and etoricoxib: A randomized clinical trialy.

BACKGROUND

This study aimed to evaluate the gene expression of cyclooxygenases (COXs) in an oral model of preemptive analgesia.

MATERIAL AND METHODS

Gingival tissue was collected during extraction of lower third molars from a randomized, triple-blind, split-mouth and placebo-controlled study. The eligible patients were randomly sorted to receive a single dose either of ibuprofen 400mg, or etoricoxib 120 mg or a placebo, one hour prior to surgery. The temporal course of RNAm was evaluated for COX-1 and -2 by means of a quantitative polymerase chain reaction in real time (RT-qPCR) at time zero and 30 minutes after the surgical procedure began, and it was correlated with clinical parameters (pain and maximum mouth opening).

RESULTS

There was a significant increase in COX-1 expression between T0 and T30 in ibuprofen (=0.004) and etoricoxib (=0.010) groups. As regards COX-2, there were increases from T0 to T30 in all groups (placebo, =0.012; ibuprofen, <0.001; etoricoxib, <0.001). All groups showed a significant decrease in COX-2:COX-1 ratio from T0 to T30 (placebo, =0.013; ibuprofen, <0.001; etoricoxib, =0.047). Experimental groups showed a significant correlation between COX-1 and COX-2 levels and clinical pain parameters.

CONCLUSIONS

The present preemptive analgesia study concludes that COX-2 RNAm induction was directly linked to third molar-related tissue inflammation and that the relation between COX-1 and COX-2 levels were inversely proportional to the preemptively administered nonsteroidal anti-inflammatory drugs COX-2 selectivity. Preemptive analgesia, dental extraction, cyclooxygenases, real-time polymerase chain reaction.