Effect of Low-magnitude high-frequency vibration on IL-6 levels in gingival crevicular fluid during orthodontic treatment: a pilot study

Low-magnitude high-frequency (LMHF) vibration has been suggested as an adjunct to orthodontic treatment to modulate inflammatory responses and potentially influence tooth movement. However, its effect on cytokine expression, particularly Interleukin-6 (IL-6), in gingival crevicular fluid remains unclear. This exploratory pilot study included 9 participants randomly allocated to 3 groups ( n = 3 per group): control (orthodontic treatment only), experimental group 1 (80 Hz LMHF vibration), and experimental group 2 (130 Hz LMHF vibration). Gingival crevicular fluid samples were collected from six standardized sites per participant at baseline (T0) and after 7 days (T1). IL-6 mRNA expression was quantified using real-time polymerase chain reaction and analyzed using the Livak and Schmittgen method (2⁻ΔΔCt), with normalization to glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Non-parametric tests were employed due to the small sample size ( n = 9) and the non-normal distribution of the data, as indicated by the normality tests. Both LMHF vibration groups demonstrated a reduction in IL-6 expression relative to baseline compared to the control group after 7 days. However, intergroup differences were not statistically significant. Within the limitations of this pilot study, adjunctive LMHF vibration did not produce a statistically significant effect on IL-6 expression during early orthodontic tooth movement. Although a decreasing trend was observed, the findings are preliminary and should be interpreted with caution. Further large, well-designed studies are required to establish its potential role in orthodontics and oral health care.