title: Orthodontic mini-implant diameter does not affect in-situ linear microcrack generation in the mandible or the maxilla.
abstract: BACKGROUND
  Microdamage reduces bone mechanical properties and thus could contribute to implant failure. The objective of this study was to investigate whether the diameter of mini-implants affects linear microcrack generation and whether this differs between the mandible and the maxilla because of their contrasting cortical thicknesses.
  
  
  METHODS
  Maxillary and mandibular quadrants of 5 dogs were randomly assigned to receive, in situ, no pilot drilling or mini-implant insertion (control), pilot drilling only without mini-implants, or pilot drilling plus a mini-implant of 1 of 3 diameters: 1.4 mm (n = 18), 1.6 mm (n = 18), and 2.0 mm (n = 18). Linear microcracks were assessed on basic fuchsin-stained sections by using epifluorescence microscopy.
  
  
  RESULTS
  Pilot drilling without mini-implant insertion produced significantly higher linear microcrack burdens in the mandible compared with the maxilla. In the both the mandible and the maxilla, all implants produced higher linear microcrack burdens than did the controls, yet there were no differences between the 3 implant diameters.
  
  
  CONCLUSIONS
  Neither the diameter of the mini-implant nor the site of insertion (mandible vs maxilla) had a significant effect on the amount of linear microdamage adjacent to the implant when the implants were inserted after pilot drilling in situ.
authors.affiliation: Department of Orthodontics and Oral Facial Genetics, School of Dentistry, Indiana University, Indianapolis, USA.
authors.forename: Sean Shih-Yao
authors.initials: SS
authors.lastname: Liu
authors.forename: Enrique
authors.initials: E
authors.lastname: Cruz-Marroquin
authors.forename: Jun
authors.initials: J
authors.lastname: Sun
authors.forename: Kelton T
authors.initials: KT
authors.lastname: Stewart
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Allen
mesh_terms: D000818:Animals; D015921:Dental Implants / Q000009:adverse effects*; D004285:Dogs; D008337:Mandibular Fractures / Q000473:pathology*; D008440:Maxillary Fractures / Q000473:pathology*; D008904:Miniaturization; D052280:Orthodontic Anchorage Procedures / Q000009:adverse effects* / Q000295:instrumentation*; D011897:Random Allocation
chemical_list: D015921:Dental Implants