Lack of Interleukin 1-beta Expression Following Orthodontic Induced Root Resorption

Abstract

Objective: To determine the effect of orthodontic tooth movement on the expression ofinterleukin-1β mRNA in rats using RT-PCR.Materials and Methods: Sample consisted of eighteen 8-week-old male Wistar rats. Theright maxillary first molar of each animal was protracted using an orthodontic protraction appliance.The left maxillary first molar received no treatment and was assigned as the controlgroup. On day 21, all rats were sacrifice and divided in two equal groups. The first group,group (A), was histologically evaluated for the presence and size of potential resorptive lacunae.The second group, group (B), was investigated using RT-PCR in order to determineIL-1β mRNA expression.Results: Measurements revealed that the mean tooth movement was 0.23 mm in group Aand 0.24 mm in group B. The mean depth of the resorptive lacunae was 0.17×10-11 mm2 inthe control group and 4.9×10-11 mm2 in the intervention group (control group: left maxillaryfirst molars; right maxillary first molars were divided to group A & B, histologic study of groupA assures the existence of resorptive lacunae and its extent relative to control group). Thedifference between the two groups was statistically significant (p<0.05). The RT-PCR evaluationshowed no significant differences in IL-1β mRNA expressions of resorptive lacunaebetween the treated and untreated groups.Conclusion: Although interleukin1-beta is the most potent stimulator of bone resorptionand mediator of inflammatory response, the present study showed that the IL-1beta mRNAwas not expressed more significantly in root resorption lacunae of the treated molars relativeto the control group.

Keywords

• Interleukin-1 beta
• Gene Expression
• Root Resorption
• Orthodontics