title: Morphological evaluation of the active tip of six types of orthodontic mini-implants.
abstract: OBJECTIVE
  To morphologically evaluate the active tip of six different types of self-drilling mini-implants for orthodontic anchorage.
  
  
  METHODS
  Images of the active tips of the mini-implants were obtained with a Zeiss optical microscope Stemi 200-C, with magnification of 1.6X. The images of the surface were viewed with the Axio Vision program (Zeiss, Jena, Germany) to calculate linear and angular measures. Mini-implant morphology and the details of tips and threads were also evaluated through Scanning Electronic Microscopy (SEM) (JEOL, model JSM5800 LV - JEOL, Tokyo, Japan) with magnifications of 90X and 70X, respectively. The evaluation of the mini-implant taper shape was assessed using the formula: (b - a) / (2 x D).
  
  
  RESULTS
  The following variables were measured: (1) active tip width, (2) major diameter of external thread, (3) minor diameter of internal thread and taper of the mini-implant, (4) number of threads and lead of the screw, (5) angle of thread, (6) flank width and (7) pitch width.
  
  
  CONCLUSIONS
  Mini-implants from different manufacturers presented active tips with different characteristics. Mechanical testing is necessary to correlate the analyzed characteristics aiming to determine the best performance.
authors.affiliation: UFF, Niterói, RJ, Brazil. flaviamitiko@yahoo.com.br
authors.forename: Flávia Mitiko Fernandes
authors.initials: FM
authors.lastname: Kitahara-Céia
authors.forename: Tatiana Féres
authors.initials: TF
authors.lastname: Assad-Loss
authors.forename: José Nelson
authors.initials: JN
authors.lastname: Mucha
authors.forename: Carlos Nelson
authors.initials: CN
authors.lastname: Elias
mesh_terms: D001863:Bone Screws; D015921:Dental Implants; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation*; D016382:Orthodontic Appliance Design; D013499:Surface Properties; D019415:Torque
chemical_list: D015921:Dental Implants
keywords: Morphology; Orthodontic anchorage procedures; Orthodontics