Method: An orthodontic appliance was fabricated and applied between the molars and the incisors of rats. . In conjunction with orthodontic force commencement, the rats were treated by a single episode of 1000 shock waves and gingival crevicular fluid was collected for 3 days. The expressions and concentrations of different cytokines were evaluated by a commercial 4-multiplex fluorescent bead-based immunoassay. Every day, during three days, rats were sacrificed and the expression of different inflammatory cytokines was evaluated by immunohistochemical staining.
Result: 4-multiplex fluorescent bead-based immunoassay: All cytokines displayed a similar trend in both the shockwave treated and non-treated groups whereby the concentration peaked on the first day and declined thereafter. In all cases the different cytokine concentrations in the shockwave treated group was smaller compared to the non-treated, however a statistical significant differences was found only in regards to sRANKL (p=0.011) and a trend towards statistical significance was demonstrated in IL-6 on day 1 (p=0.065). Immunohistochemical staining: The percentage of cells expressing all inflammatory cytokines during the study's first two days was reduced in a statistically significant manner in the shock wave treated group compared to the non-treated group. On the first day, the percentage of cells expressing IL-1β and RANKL in the compression side peaked in both groups, with a sequential rise in TRAP positive cells' number.
Conclusion: The application of shockwave therapy during orthodontic tooth movement influences the expression of the inflammatory cytokines profile and may alternate the periodontal remodeling expected rate.