A quantitative analysis of macrophage-colony-stimulating factor in peri-miniscrew implant crevicular fluid before and after orthodontic loading.

Objectives: To analyze macrophage-colony-stimulating factor (M-CSF), a bone remodeling biomarker in the peri-miniscrew implant crevicular fluid (PMICF) after insertion and orthodontic loading.

Materials and methods: This prospective study included 40 miniscrew implant (MSI) sites in 10 subjects undergoing fixed orthodontic mechanotherapy utilizing miniscrew anchorage. After dental alignment, miniscrews were inserted between the second premolar and first molar roots. After 21 days of insertion, MSIs were direct loaded with closed-coil springs (200 g force) for en masse retraction of anterior teeth. PMICF was collected with Periopaper™ strips from the gingival crevice around MSIs at six time points (T1-T6: 1 hour, 1 day, 21 days postinsertion, and 7, 21, and 42 days postloading). PMICF was quantified for M-CSF by enzyme-linked immunosorbent assay. Paired comparison of mean M-CSF concentrations before and after loading stages (T1-T6) was made using the Wilcoxon signed-rank test.

Results: The mean M-CSF concentration showed a significant peak at T3 (21 days postinsertion; 12.646 pg/mL; T1 vs T3: P < .0001). After orthodontic loading of miniscrews, M-CSF levels increased to 13.570 pg/mL at T4 (7 days after loading; T1 vs T4: P < .001) and maintained at a plateau to T5 (21 days postloading; 11.994 pg/mL). However, the difference between preloading and postloading was not statistically significant (T3 vs T4).

Conclusions: The maximum M-CSF activity around MSIs was observed at around 3 weeks of miniscrew insertion, suggesting underlying bone remodeling after surgical injury. However, orthodontic force on MSIs did not cause any significant surge in M-CSF levels postloading.