title: Mechanical stability and clinical applicability assessment of novel orthodontic mini-implant design.
abstract: OBJECTIVE
  To compare the stability and clinical applicability of a novel orthodontic mini-implant design (N2) with the most widely used commercially available (CA) design.
  
  
  METHODS
  Two groups of mini-implants were tested: a CA design (1.5-mm diameter, 6-mm length) and N2 (3-mm diameter, 2-mm length, tapered shape). Implants were inserted in bone blocks of cortical bone simulation with varying densities (20 pounds per cubic foot [pcf], 30 pcf, and 40 pcf). A torque test was used to measure maximum insertion torque (MIT) and maximum removal torque (MRT). Compression and tension force vectors were applied at angles of 10°, 20°, 30°, and 40° using customized load pins to determine primary stability.
  
  
  RESULTS
  Mean MIT and MRT were higher in the N2 than the CA design at all three cortical bone densities except MRT in 20 pcf bone (not statistically significant). The mean compression force required to displace the N2 at all distances and angulations was greater for the N2 than the CA design. At all displacement distances, the highest mean tension force required for N2 displacement was at 10° angulation, whereas at 30° and 40°, the mean tension force required to displace the CA design was greater.
  
  
  CONCLUSIONS
  The primary stability of the N2 is superior to that of the CA design and is promising for both orthodontic and orthopedic clinical applicability, especially under compression force. The short length of the N2 reduces risk of damage to anatomic structures and root proximity during placement and orthodontic treatment. The stability of the N2 may be compromised in areas of high bone density and highly angulated tension force.
authors.affiliation: Section of Orthodontics, School of Dentistry, University of California, Los Angeles, Los Angeles, Calif 90095, USA.
authors.forename: Ha Na
authors.initials: HN
authors.lastname: Song
authors.forename: Christine
authors.initials: C
authors.lastname: Hong
authors.forename: Robert
authors.initials: R
authors.lastname: Banh
authors.forename: Tania
authors.initials: T
authors.lastname: Ohebsion
authors.forename: Greg
authors.initials: G
authors.lastname: Asatrian
authors.forename: Ho-Yin
authors.initials: HY
authors.lastname: Leung
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Wu
authors.forename: Won
authors.initials: W
authors.lastname: Moon
mesh_terms: D015519:Bone Density; D018786:Bone Substitutes / Q000737:chemistry*; D019245:Compressive Strength; D003722:Dental Alloys / Q000737:chemistry*; D015921:Dental Implants; D003799:Dental Stress Analysis; D008422:Materials Testing; D052280:Orthodontic Anchorage Procedures / Q000379:methods*; D016382:Orthodontic Appliance Design; D013314:Stress, Mechanical; D013718:Tensile Strength; D019415:Torque
chemical_list: D018786:Bone Substitutes; D003722:Dental Alloys; D015921:Dental Implants