title: Retrieval analysis of immediately loaded orthodontic mini-implants: material and tissue characterization.
abstract: OBJECTIVE
  To investigate the morphological and compositional alterations of retrieved orthodontic mini-implants and the type of adjacent bone, in relation to loading period and anatomical region.
  
  
  METHODS
  Seventy orthodontic mini-implants (Aarhus: n = 35 and AbsoAnchor: n = 35) were placed in the maxilla and mandible of 33 orthodontic patients for anchorage purposes. All mini-implants were immediately loaded for a period specified by treatment plan. Fifty-nine mini-implants were retrieved (Aarhus: n = 29 and AbsoAnchor: n = 30) and examined by stereomicroscopy, reflection Fourier transform infrared microspectroscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. Tissue samples adjacent to the implants were histologically examined to identify the bone type.
  
  
  RESULTS
  Changes in surface finish, formation of biological integuments, and compositional alterations mainly due to adsorption of proteinaceous material (rich in C, O, N, OH, NH, CH2/CH3, amide I, II, and III, and CH-OH) were identified in all mini-implants. In some cases, mineralized fragments were identified (rich in Ca, P, and Ca-P). In 25 out of the 59 histological sections examined, woven and lamellar bone types were detected. In 12 sections, only woven bone was detected, whereas in the residual 22, only lamellar bone was identified. A significant correlation was found between histological result and loading time but not between histology and region.
  
  
  CONCLUSIONS
  Morphological and elemental alterations were found for both types of mini-implant surfaces. An increase of the loading period increased the possibility of lamellar bone development around mini-implants.
authors.affiliation: *Orthodontics, mvasoglou@dent.uoa.gr.
authors.forename: Michail
authors.initials: M
authors.lastname: Vasoglou
authors.affiliation: **Oral Pathology and.
authors.forename: Evanthia
authors.initials: E
authors.lastname: Chrysomali
authors.affiliation: ***Biomaterials, School of Dentistry, National and Kapodistrian University of Athens, Greece.
authors.forename: Spiros
authors.initials: S
authors.lastname: Zinelis
authors.affiliation: *Orthodontics.
authors.forename: Ilias
authors.initials: I
authors.lastname: Bitsanis
authors.affiliation: *Orthodontics.
authors.forename: Nikos
authors.initials: N
authors.lastname: Haralambakis
authors.affiliation: *Orthodontics.
authors.forename: Margarita
authors.initials: M
authors.lastname: Makou
authors.affiliation: ***Biomaterials, School of Dentistry, National and Kapodistrian University of Athens, Greece.
authors.forename: George
authors.initials: G
authors.lastname: Epsilonliades
mesh_terms: D000328:Adult; D015921:Dental Implants; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible / Q000473:pathology / Q000503:physiopathology; D008422:Materials Testing / Q000379:methods; D008437:Maxilla / Q000473:pathology / Q000503:physiopathology; D008855:Microscopy, Electron, Scanning; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation* / Q000379:methods; D013314:Stress, Mechanical; D055815:Young Adult
chemical_list: D015921:Dental Implants