title: Impact of mini-implant length on stability at the initial healing period: a controlled clinical study.
abstract: BACKGROUND
  Aim of the study was to assess the impact of the length of mini-implants inserted in the midpalatal region on the stability at the initial healing period.
  
  
  METHODS
  A sample of 20 consecutively treated patients (15.6 ± 7.2 years) was examined. A long mini-implant with a length of 11 mm and a diameter of 2 mm was inserted into the anterior palate of each patient. Resonance frequency analysis (RFA) was performed after insertion (T0), two weeks (T1), four weeks (T2), and six weeks (T3). Insertion depth (ID) and the maximum insertion torque (IT) were measured. RFA, ID and IT data were tested for correlations. RFA values were tested for statistical differences between the different times. Data was compared to a matched control group of patients who received short mini-implants with a length of 9 mm and a diameter of 2 mm.
  
  
  RESULTS
  Mean ID was 9.5 ± 0.6 mm and mean IT was 17.9 ± 3.8 Ncm. A correlation was found between RFA and ID (r = 0.59, P < .01). From T0 to T1 the stability (33.4 ± 3.5 ISQ) decreased highly significantly by 5.3 ± 3.5 ISQ values (P < .001) and significantly from T1 and T2 (P < .05) by 3.5 ± 3.7 ISQ values. From T2 on RFA nearly remained unchanged (-1.7 ± 3.9 ISQ; P > .05). At T1 stability was significantly lower than the control group. From T2 on there were no significant differences between the groups.
  
  
  CONCLUSIONS
  Long mini-implants provide high stability when inserted in the midpalatal region. After initial decrease RFA values remained stable from four weeks on and did not differ from the control group.
  
  
  BACKGROUND
  2013081293 (Clinical study register, University of 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; D000328:Adult; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention; D005260:Female; D006801:Humans; D008297:Male; D010159:Palate; D011446:Prospective Studies; D011474:Prosthesis Design; D014945:Wound Healing; D055815:Young Adult
chemical_list: D015921:Dental Implants