A study of interleukin 1β levels in peri-miniscrew crevicular fluid (PMCF)

Abstract

Background: This study provides a vital insight in assessing the clinical and biochemical changes in interleukin (IL)-1β levels in peri-miniscrew crevicular fluid (PMCF) during the course of orthodontic tooth movement.

Methods: The study comprised the analysis of IL-1β in peri-miniscrew crevicular fluid obtained from crevices around the miniscrews inserted in 11 patients (eight females and three males, mean age 17.3 ± 4.64 years) with all first premolar extraction and maximum anchorage requirement using miniscrew-supported anchorage. Miniscrews were loaded at 3 weeks after placement by 200-g nitinol closed coil springs of 9-mm length for en masse retraction. Peri-miniscrew crevicular fluid was collected at miniscrew placement (T1), at 3 weeks (T2/baseline) and on loading at 0 (T3) and 1 day (T4), 21 (T5), 72 (T6), 120 (T7), 180 (T8) and 300 (T9) days. IL-1β levels were estimated by enzyme-linked immunosorbent assay (ELISA). Peri-miniscrew tissue was examined for signs of inflammation, and also, miniscrew mobility was assessed with Periotest and handles of two mouth mirrors.

Results: IL-1β levels in all miniscrews were significantly higher at T1 and peaked again at T4 showing a bimodal peak. However, there was a gradual and statistically significant decrease in IL-1β till T5, while further changes till the end of the study were statistically not significant.

Conclusions: The changing levels of IL-1β levels in PMCF over a duration of 300 days are suggestive of the underlying inflammatory process. IL-1β levels in PMCF show a significant rise during miniscrew insertion and on immediate loading. The trend of gradually reducing IL-1β levels around the miniscrew over the period after loading towards baseline is suggestive of adaptive bone response to stimulus.

Figure 1

Assembly showing retraction mechanics using miniscrew as anchorage.

Figure 2

Trend of IL-1β levels in PMCF at different time intervals. 1-T1 (4 hours after Implant placement), 2-T2 (Baseline: 3 weeks, just prior to loading), 3-T3 (Just after loading: 0 day), 4-T4 (At 24 hours after loading: 1 day), 5-T5 (At 21 days), 6-T6 (At 72 days), 7-T7 (At 120 days), 8-T8 (At 180 days) and 9-T9 (At 300 days). The boxes represent the values from the 25th to the 75th percentile. The middle lines represent the medians. The vertical lines extend from the minimal to the maximal values, exluding the outliers marked with small dark circles.