title: Influence of surface characteristics on survival rates of mini-implants.
abstract: OBJECTIVE
  To compare the clinical performance and the survival rate of two mini-implant systems with different surface characteristics under immediate orthodontic loading.
  
  
  METHODS
  Seventeen machined titanium (MT) mini-implants and 15 sandblasted, large grit, acid-etched (SLA) mini-implants were placed in 10 patients. The mini-implants were immediately loaded and the patients seen at 7, 14, 30, 60, and 150 days. Clinical parameters such as anatomical location, character of the soft tissue at the screw head emergence, type of mini-implant system, diameter, and length were analyzed. In addition, the insertion torque recorded at the time of insertion was also assessed. Survival rate and clinical parameters were evaluated by the chi-square exact tests using the SAS version 9.1.
  
  
  RESULTS
  The overall survival rate was 87.5%. Over the four failing mini-implants, three were MT and one SLA resulting in an individual survival rate of 82.4% and 93.4%, respectively. In the failure group, all the fixtures had their screw emergence at the oral mucosa and recorded a torque range of less than 15 Ncm. The insertion torque statistically influenced the survival rate of the mini-implants (P < .05). Surface treatment, anatomical location, as well as soft tissue emergence were not statistically significant.
  
  
  CONCLUSIONS
  Surface characteristics did not appear to influence survival rates of immediately loaded mini-implants.
authors.affiliation: Department of Periodontics, University of Alabama at Birmingham, 1919 7th Ave South, SDB 412, Birmingham, AL 35294, USA. kcchaddad@gmail.com
authors.forename: Karim
authors.initials: K
authors.lastname: Chaddad
authors.forename: André F H
authors.initials: AF
authors.lastname: Ferreira
authors.forename: Nico
authors.initials: N
authors.lastname: Geurs
authors.forename: Michael S
authors.initials: MS
authors.lastname: Reddy
mesh_terms: D000134:Acid Etching, Dental; D000293:Adolescent; D000328:Adult; D000368:Aged; D001863:Bone Screws; D045662:Dental Etching / Q000379:methods; D003764:Dental Materials / Q000737:chemistry; D004868:Equipment Failure; D005500:Follow-Up Studies; D006801:Humans; D008422:Materials Testing; D008875:Middle Aged; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation*; D016382:Orthodontic Appliance Design; D013314:Stress, Mechanical; D013499:Surface Properties; D016019:Survival Analysis; D014025:Titanium / Q000737:chemistry; D014087:Tooth Movement Techniques / Q000295:instrumentation; D019415:Torque
chemical_list: D003764:Dental Materials; D014025:Titanium