title: Surface analysis of 2 orthodontic mini-implants after clinical use.
abstract: BACKGROUND
  The purpose of this study was to analyze the design and surface morphology of 2 brands of mini-implants before and after 12 to 18 months of clinical use.
  
  
  METHODS
  We studied 22 mini-implants sold in the Brazilian market by 2 companies (Forestadent, Pforzheim, Germany; and Dental Morelli, Sorocaba, São Paulo, Brazil). The surface morphology of the mini-implants was analyzed by scanning electron microscopy before and after insertion in the oral environment to aid orthodontic movement.
  
  
  RESULTS
  The Forestadent and the Morelli mini-implants showed different shapes (size, screw thread design), and the surface morphology changed after clinical use. The most important surface morphology alterations after clinical use were strain in several parts and fracture of the active thread part of some mini-implants.
  
  
  CONCLUSIONS
  The results of the analyses showed that the screw threads of the mini-implants differ in pitch, angle, and length. The mini-implants also showed differences in body design, active tip, and taper. These differences affect the performance of the mini-implants. After clinical use, all mini-implants showed surface degradation, plastic deformation, and some fractures.
authors.affiliation: Professor, Department of Orthodontics, School of Health Science, Vale do Rio Doce University, Governador Valadares, Minas Gerais, Brazil. Electronic address: guilherme@ortodontiamarigo.com.br.
authors.forename: Guilherme
authors.initials: G
authors.lastname: Marigo
authors.affiliation: Adjunct professor, Materials Science Department, Military Institute of Engineering, Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Carlos Nelson
authors.initials: CN
authors.lastname: Elias
authors.affiliation: Professor, Department of Orthodontics, School of Health Science, Vale do Rio Doce University, Governador Valadares, Minas Gerais, Brazil.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Marigo
mesh_terms: D006801:Humans; D016382:Orthodontic Appliance Design; D009967:Orthodontic Appliances; D013499:Surface Properties