title: Retention and Mechanical Behavior of Attachment Systems for Implant-Retained Auricular Prostheses.
abstract: OBJECTIVE
  Auricular prostheses are artificial substitutes for facial defects. The retention of these has often been a problem. This study aimed to evaluate the mechanical behavior of 3 retained auricular prosthetic connections when submitted to a mechanical cycling test.
  
  
  METHODS
  Twelve samples with installed implants were obtained and divided into 3 groups according to their retention system with 4 samples in each group. I: bar-clip system; II: magnet system; and III: ball/o-ring system. Each of samples was submitted to the pull-out test during 3240 cycles (f = 0.5 Hz) to determine its tensile strength. The mechanical cycling test was performed using the servo-hydraulic machine MTS 810-Flex Test 40 (Eden Prairie, MN) that had a 2.5 mm shift at a 10 mm/s velocity. The retaining strength for each of the samples was obtained at 7 intervals.
  
  
  RESULTS
  The tensile strength for the group retained by the bar-clip system (29.60 N) was higher with statistically significant difference (P < 0.05) when compared with the group retained by the ball/o-ring system (9.41 N) and magnets system (8.61 N) for all periods assessed. The ball/o-ring system showed loss of retention during the fatigue test (Kruskal-Wallis, chi-squared = 17.28; P < 0.01).
  
  
  CONCLUSIONS
  The evaluated systems showed a tensile strength compatible with the clinical use and no fractures of the components were observed.
authors.affiliation: *Division of Oral and Maxillofacial Surgery, Piracicaba Dental School, State University of Campinas †Department of Prosthodontics and Periodontology, Piracicaba Dental School, State University of Campinas, Piracicaba, São Paulo, Brazil ‡Division of Oral and Maxillofacial Surgery, Universidad de La Frontera §Center for Biomedical Research, Universidad Autónoma de Chile, Temuco, Chile.
authors.forename: Eder Alberto
authors.initials: EA
authors.lastname: Sigua-Rodriguez
authors.forename: Douglas Rangel
authors.initials: DR
authors.lastname: Goulart
authors.forename: Zarina Tatia
authors.initials: ZT
authors.lastname: Santos
authors.forename: Natalia
authors.initials: N
authors.lastname: Alvarez-Pinzon
authors.forename: Sergio
authors.initials: S
authors.lastname: Olate
authors.forename: José Ricardo
authors.initials: JR
authors.lastname: de Albergaria-Barbosa
mesh_terms: D001696:Biomechanical Phenomena; D000069343:Bone-Implant Interface; D004431:Ear, External / Q000601:surgery*; D006801:Humans; D019736:Prostheses and Implants; D011474:Prosthesis Design; D011475:Prosthesis Failure; D060489:Prosthesis Retention / Q000379:methods*; D013718:Tensile Strength