Strontium-Hydroxyapatite Coated Mini-Screws: Antibacterial Effect and Stability

This randomized controlled clinical trial aims to evaluate the antibacterial efficacy and stability of strontium-incorporated hydroxyapatite (Sr-HA) coated orthodontic mini-screws (OMSs) used for maxillary canine retraction. A double-blind, split-mouth design was employed, involving 20 patients (aged 16-20 years), each receiving two titanium alloy mini-screws (1.6 mm × 8 mm): one coated with Sr-HA (5% concentration via electrochemical deposition) and one uncoated control. A total of 40 mini-screws were assessed. Following upper first premolar extractions, canine retraction was initiated using 150 g NiTi coil springs on 17×25 SS archwires. Mini-screws were placed between the upper second premolar and first molar without flap elevation or pilot hole drilling. Parameters including screw stability, antimicrobial activity, and gingival blood flow were monitored over a 4-month period. The incorporation of Sr-HA is hypothesized to enhance mini-screw osseointegration, reduce peri-implant inflammation, and improve clinical outcomes by leveraging the osteogenic and antibacterial properties of strontium. This study aims to provide evidence supporting the use of Sr-HA coatings to reduce mini-screw failure rates in orthodontic treatment.

NCT Number	NCT07105969
Lead Sponsor	Mansoura University
Conditions	Gingival Inflammation and Loss the Orthodontic Mini-screws
Enrollment	20 participants
Start Date	2025-05-14
Primary Completion	2026-03-14 (estimated)
Study Completion	2026-05-14 (estimated)
Updated on ClinicalTrials.gov	2025-08-26