title: Evaluation of Fracture Resistance of Orthodontic Mini-implants in the Transmucosal Profile Region.
abstract: This study sought to compare the fracture resistance of three trademarked orthodontic mini-implants in the transmucosal profile region. Thirty-six mini-implants of three different brands, separated into groups I, II and III, were tested. Each group consisted of 12 mini-implants of 6 mm in length. The mean diameter and length of the transmucosal profile of the mini-implants were 1.90 and 2.0 mm in group I, 1.77 and 1.0 mm in group II and 1.50 and 1.0 mm in group III, respectively. The tests were performed on a universal testing machine in compression mode, with a 2,000 kgf load, a speed of 4.0 mm per minute and a chisel-shaped active tip, which acted cross-sectionally on the transmucosal profile. Single-criterion analysis of variance was used to compare the three brands. A significance level of 5% and test power of 80% were adopted. The mean fracture resistance achieved by the mini-implants was 172.03 ± 25.59 N for group I, 162.35 ± 30.81 N for group II and 139.69 ± 42.99 N for group III. There was no statistically significant difference in mean fracture resistance among the tested mini-implant brands.
  
  
  
  The transmucosal profile diameter does not seem to be a deciding factor in the choice of mini-implants to minimize the risk of fractures.
  
  
  
  Although being an in vitro study it is possible to believe that this new brand has a very satisfactory resistance to fracture and enables its use with great efficiency.
authors.affiliation: Department of Orthodontics, CEUMA University, São Luís Maranhão, Brazil.
authors.forename: Arilton Mota
authors.initials: AM
authors.lastname: de Aguiar
authors.affiliation: Assistant Professor, Department of Orthodontics, CEUMA University São Luís, Maranhão, Brazil, 65075-120, e-mail: faubramante@hotmail.com.
authors.forename: Fausto Silva
authors.initials: FS
authors.lastname: Bramante
authors.affiliation: Department of Orthodontics, CEUMA University, São Luís Maranhão, Brazil.
authors.forename: Adelson Mota
authors.initials: AM
authors.lastname: de Aguiar
authors.affiliation: Department of Orthodontics, CEUMA University, São Luís Maranhão, Brazil.
authors.forename: Célia Regina Maio
authors.initials: CR
authors.lastname: Pinzan-Vercelino
mesh_terms: D000497:Alloys; D003722:Dental Alloys / Q000737:chemistry; D015921:Dental Implants; D003799:Dental Stress Analysis / Q000295:instrumentation; D004868:Equipment Failure; D006801:Humans; D008422:Materials Testing; D008904:Miniaturization; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation*; D016382:Orthodontic Appliance Design; D013314:Stress, Mechanical; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry
chemical_list: D000497:Alloys; D003722:Dental Alloys; D015921:Dental Implants; C031462:titanium alloy (TiAl6V4); D014025:Titanium
keywords: Orthodontic anchorage procedures; Tooth move-ment; Orthodontic appliances.