Evaluation of Surface Characteristics and Osteogenic Potential of Nano-Hydroxyapatite Coated Orthodontic Mini Screws: An In Vitro Study

Introduction: Orthodontic mini screws, used as Temporary Anchorage Devices (TADs), are pivotal in modern orthodontics. Surface modifications like nano-hydroxyapatite (nHA) coatings may enhance their biological integration. Objectives: To evaluate and compare surface morphology and osteogenic potential of uncoated versus nHA-coated mini screws. Methods: Thirty-six titanium mini screws (1.5 mm × 6 mm) were split into coated and uncoated groups. Plasma spray coating with nHA was applied. Surface analysis was done via SEM and EDX. Osteogenic compatibility was assessed using MG-63 cell lines and MTT assay at 24 and 48 hours. Results: SEM revealed nano-textured, uniform coatings. EDX confirmed Ca/P ratios matching hydroxyapatite. At 48 hours, coated screws showed significantly higher cell viability (p = 0.042), with no cytotoxicity. Conclusions: nHA coatings improve mini screw bioactivity and osteoblast proliferation. Optimization of coating methods is necessary to avoid excess bulk and tip blunting. DOI: https://doi.org/10.52783/jchr.v15.i5.9970