Comparative evaluation of displacement of bisphosphonate-coated mini-implants in anterior en-masse retraction – A randomized control split-mouth clinical trial

Objectives: The clinical displacement of mini-implants can compromise anchorage during en-masse anterior retraction. This study evaluated whether bisphosphonate-coated mini-implants reduce displacement and enhance retraction efficiency compared to uncoated implants. Material and Methods: This was a split-mouth, randomized controlled clinical trial involving 30 patients requiring maximum anchorage following premolar extraction. Patients were randomly assigned to receive either bisphosphonate-coated or uncoated mini-implants in the maxillary arch. Cone beam computed tomography superimposition was used to assess implant displacement in the X (bucco-palatal), Y (mesio-distal), and Z (vertical) axes. Retraction space closure was measured using three-dimensional digital models at 3 and 6 months. Results: Miniscrew displacement was significantly lower in the bisphosphonate-coated group in the mesio-distal (Y) direction ( p < 0.05). The coated group also showed a significantly greater rate of space closure at both 3 and 6 months ( p < 0.05). Conclusion: Bisphosphonate coating reduces mini-implant displacement and may enhance the rate of anterior retraction when used in maximum anchorage cases.