title: Local application of zoledronate enhances miniscrew implant stability in dogs.
abstract: BACKGROUND
  The primary purposes of this study were to evaluate how locally delivered zoledronate affects the longitudinal stability of miniscrew implants (MSIs) and the healing of bone around MSIs.
  
  
  METHODS
  Using a randomized split-mouth design, 60 unloaded MSIs (5 × 1.6 mm) were placed in skeletally mature male foxhound-mixed breed dogs. The MSIs were randomly assigned to bilateral pairs of pilot holes (1.1 mm) that had been injected with either bisphosphonate zoledronate (n = 30, experimental group) or buffered saline solution (n = 30, control group). MSI stability was evaluated weekly for 8 weeks using resonance frequency analyses (Osstell Mentor; Integration Diagnostics, Göteborg, Sweden). Microcomputed tomography (6-μm voxel size) was used to determine the bone volume fractions of 3 layers of bone (6-24, 24-42, and 42-60 μm) surrounding the MSIs.
  
  
  RESULTS
  Resonance frequency analysis showed that the control MSIs were significantly (P <0.05) less stable than the experimental MSIs. Although there was little or no change in stability over time for the MSIs treated with zoledronate, the stability of the control MSIs decreased during the first 4 weeks, increased through week 6, and then decreased again. The 6- to 24-μm layer closest to the MSIs, on both the experimental and the control sides, showed significantly (P <0.05) less bone than did the 24- to 42-μm and the 42- to 60-μm layers. After 8 weeks, there was significantly more cortical bone surrounding the control than the experimental MSIs. In contrast, there was significantly more trabecular bone surrounding the experimental than the control MSIs.
  
  
  CONCLUSIONS
  One small locally delivered dose of zoledronate maintained the stability of MSIs over time, primarily because of greater amounts of trabecular bone surrounding the MSIs. Even though zoledronate enhanced the stability of MSIs in dogs, it should not be used clinically until further studies confirm its safe use in patients.
authors.affiliation: Private practice, San José, Costa Rica.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Cuairán
authors.affiliation: Chairman, Department of Orthodontics, Texas A&M University Baylor College of Dentistry, Dallas, Tex.
authors.forename: Phillip M
authors.initials: PM
authors.lastname: Campbell
authors.affiliation: Assistant clinical professor, Restorative Sciences, Texas A&M University Baylor College of Dentistry, Dallas, Tex.
authors.forename: Elias
authors.initials: E
authors.lastname: Kontogiorgos
authors.affiliation: Associate professor, Department of Orthodontics, Texas A&M University Baylor College of Dentistry, Dallas, Tex.
authors.forename: Reginald W
authors.initials: RW
authors.lastname: Taylor
authors.affiliation: Research scientist, Instituo Americano de Pesquisa e Ensino Odontologico, Curitiba, Paraná, Brazil.
authors.forename: Ana Cláudia
authors.initials: AC
authors.lastname: Melo
authors.affiliation: Regents professor and director of Orthodontic Research, Department of Orthodontics, Texas A&M University Baylor College of Dentistry, Dallas, Tex. Electronic address: phbuschang@bcd.tamhsc.edu.
authors.forename: Peter H
authors.initials: PH
authors.lastname: Buschang
mesh_terms: D000818:Animals; D050071:Bone Density Conservation Agents / Q000008:administration & dosage*; D001863:Bone Screws; D003722:Dental Alloys / Q000737:chemistry; D004164:Diphosphonates / Q000008:administration & dosage*; D004285:Dogs; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D007093:Imidazoles / Q000008:administration & dosage*; D007267:Injections; D008297:Male; D008334:Mandible / Q000187:drug effects / Q000601:surgery; D008437:Maxilla / Q000187:drug effects / Q000601:surgery; D008904:Miniaturization; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation*; D016348:Osseointegration / Q000187:drug effects*; D010027:Osteotomy / Q000379:methods; D011897:Random Allocation; D013997:Time Factors; D014025:Titanium / Q000737:chemistry; D014159:Transducers; D014732:Vibration; D055114:X-Ray Microtomography / Q000379:methods; D000077211:Zoledronic Acid
chemical_list: D050071:Bone Density Conservation Agents; D003722:Dental Alloys; D004164:Diphosphonates; D007093:Imidazoles; D000077211:Zoledronic Acid; D014025:Titanium