title: Mini-implant stability at the initial healing period: a clinical pilot study.
abstract: OBJECTIVE
  To evaluate the changes of mini-implant stability over the initial healing period in humans.
  
  
  METHODS
  A sample of 19 consecutively treated patients (mean age 15.5 ± 7.3 years) was examined. In each patient, a mini-implant of a size of 2 × 9 mm was inserted into the anterior palate. Implant stability was assessed using resonance frequency analysis (RFA) immediately after insertion (T0), 2 weeks later (T1), 4 weeks later (T2), and 6 weeks later (T3). Insertion depth (ID) and the maximum insertion torque (IT) were measured. Data were tested for correlations between RFA, ID, and IT. All RFA values were tested for statistically significant differences between the different times.
  
  
  RESULTS
  The mean ID was 7.5 ± 0.6 mm, and the mean IT was 16.8 ± 0.6 Ncm. A correlation was found between RFA and ID (r = .726, P < .0001), whereas no correlations between RFA and IT or between IT and ID were observed. From T0 to T1, the stability (36.1 ± 6.1 implant stability quotient [ISQ]) decreased nonsignificantly by 4.9 ± 6.1 ISQ values (P > .05). Between T1 and T2, the stability decreased highly significantly (P < .001) by 7.9 ± 5.9 ISQ values. From T2 on, RFA remained nearly unchanged (-1.7 ± 3.5 ISQ; P > .05).
  
  
  CONCLUSIONS
  Mini-implant stability is subject to changes during the healing process. During weeks 3 and 4, a significant decrease of the stability was observed. After 4 weeks, the stability did not change significantly.
authors.affiliation: a  Instructor, Department of Orthodontics, Heinrich-Heine-University, Düsseldorf, Germany.
authors.forename: Manuel
authors.initials: M
authors.lastname: Nienkemper
authors.forename: Benedict
authors.initials: B
authors.lastname: Wilmes
authors.forename: Alexander
authors.initials: A
authors.lastname: Pauls
authors.forename: Dieter
authors.initials: D
authors.lastname: Drescher
mesh_terms: D000293:Adolescent; D015921:Dental Implants; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008904:Miniaturization; D009061:Mouth Mucosa / Q000473:pathology / Q000601:surgery; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation*; D016348:Osseointegration / Q000502:physiology; D010159:Palate / Q000473:pathology / Q000601:surgery; D010865:Pilot Projects; D011446:Prospective Studies; D013499:Surface Properties; D019415:Torque; D014732:Vibration; D014945:Wound Healing / Q000502:physiology
chemical_list: D015921:Dental Implants