Assessment of coated orthodontic miniscrews with chlorhexidine hexametaphosphate antimicrobial nanoparticles: A randomized clinical trial.

Background: Using miniscrews to control anchorage made the application of force for various orthodontic treatment approaches easier and increased their effectiveness. Some problems may occur during the use of miniscrews, such as peri‑implant mucositis, mobility, postoperative pain, and failure. This study compared the success rate of miniscrews coated with chlorhexidine hexametaphosphate antimicrobial nanoparticles with that of uncoated miniscrews.

Methods: In a double-blind randomized controlled clinical trial using a split-mouth design, 80 miniscrews were inserted symmetrically into 40 individuals between the maxillary second premolar and first molar. Random allocation software was used to distribute the coated and uncoated miniscrews. The patients were monitored monthly, for a duration of 4 months. The main measure of interest was the success rate of miniscrews, which was assessed throughout follow-up periods of up to 4 months. The secondary objective was the assessment of the mobility of the miniscrews, peri‑implant health, and pain perception. A Wilcoxon signed-rank test and Kaplan-Meier survival analysis were applied to analyze the data.

Results: Main outcome: After the 4-month follow-up, the success rates of the miniscrews for coated and uncoated samples were 81.3% and 84.4%, respectively, which was a statistically insignificant difference.

Secondary outcome: Mobility and peri‑implant health were not statistically different between the coated and uncoated miniscrew groups. Pain intensity was rated higher on the first day, then decreased gradually, diminishing completely on the sixth and seventh day. However, the pain perception between the coated and uncoated miniscrews did not differ statistically.

Conclusions: Chlorhexidine-hexametaphosphate nanoparticles did not increase the success rate and stability, nor did they enhance peri‑implant health or affect pain perception during the short observation period.

Trial registration: This trial was registered at ClinicalTrials.gov; ID: NCT06124235.