title: Ultraviolet photofunctionalization increases removal torque values and horizontal stability of orthodontic miniscrews.
abstract: BACKGROUND
  The objective of this study was to examine the effects of ultraviolet-mediated photofunctionalization of miniscrews and the in-vivo potential of bone-miniscrew integration.
  
  
  METHODS
  Self-drilling orthodontic miniscrews made from a titanium alloy were placed in rat femurs. Photofunctionalization was performed by treating the miniscrews with ultraviolet light for 12 minutes with a photo device immediately before implantation. Maximum insertion torque (week 0), removal torque (weeks 0 and 3), and resistance to lateral tipping force (week 3) were examined.
  
  
  RESULTS
  The removal torque at 3 weeks of healing was higher for the photofunctionalized screws than for the untreated screws. The regenerated bone tissue was more intact and contiguous around the photofunctionalized miniscrews than around the untreated ones. The miniscrew-bone complex seemed to produce interface failure, not cohesive fracture, in both groups. The displacement of untreated screws under a lateral tipping force was greater than that of photofunctionalized miniscrews.
  
  
  CONCLUSIONS
  These results suggest that photofunctionalization increases the bioactivity of titanium-alloy miniscrews and improves the anchoring capability of orthodontic miniscrews, even without modification of the surface topography.
authors.affiliation: Visiting scholar, Laboratory for Bone and Implant Sciences, The Jane and Jerry Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, School of Dentistry, University of California at Los Angeles, Los Angeles, Calif; associate professor, Department of Orthodontics, School of Dentistry, Aichi Gakuin University, Nagoya, Japan. Electronic address: machako@dpc.agu.ac.jp.
authors.forename: Masako
authors.initials: M
authors.lastname: Tabuchi
authors.affiliation: Visiting scholar, Laboratory for Bone and Implant Sciences, The Jane and Jerry Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, School of Dentistry, University of California at Los Angeles, Los Angeles, Calif.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Ikeda
authors.affiliation: Visiting scholar, Laboratory for Bone and Implant Sciences, The Jane and Jerry Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, School of Dentistry, University of California at Los Angeles, Los Angeles, Calif.
authors.forename: Kahori
authors.initials: K
authors.lastname: Nakagawa
authors.affiliation: Visiting scholar, Laboratory for Bone and Implant Sciences, The Jane and Jerry Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, School of Dentistry, University of California at Los Angeles, Los Angeles, Calif.
authors.forename: Makoto
authors.initials: M
authors.lastname: Hirota
authors.affiliation: Visiting scholar, Laboratory for Bone and Implant Sciences, The Jane and Jerry Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, School of Dentistry, University of California at Los Angeles, Los Angeles, Calif.
authors.forename: Wonhee
authors.initials: W
authors.lastname: Park
authors.affiliation: Professor, Department of Orthodontics, School of Dentistry, Aichi Gakuin University, Nagoya, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Miyazawa
authors.affiliation: Professor and chairman, Department of Orthodontics, School of Dentistry, Aichi Gakuin University, Nagoya, Japan.
authors.forename: Shigemi
authors.initials: S
authors.lastname: Goto
authors.affiliation: Professor, Laboratory for Bone and Implant Sciences, The Jane and Jerry Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, School of Dentistry, University of California at Los Angeles, Los Angeles, Calif.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ogawa
mesh_terms: D000497:Alloys; D000818:Animals; D001696:Biomechanical Phenomena; D001861:Bone Regeneration / Q000502:physiology; D001863:Bone Screws; D003722:Dental Alloys / Q000528:radiation effects; D045662:Dental Etching / Q000379:methods*; D005269:Femur / Q000601:surgery; D057927:Hydrophobic and Hydrophilic Interactions; D008297:Male; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D008904:Miniaturization; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation*; D016382:Orthodontic Appliance Design; D016348:Osseointegration / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors; D014025:Titanium / Q000528:radiation effects; D019415:Torque; D014466:Ultraviolet Rays; D014945:Wound Healing / Q000502:physiology
chemical_list: D000497:Alloys; D003722:Dental Alloys; C031462:titanium alloy (TiAl6V4); D014025:Titanium