title: Effect of Anchor Length on the Pullout Strength of Palatal Mini Implants.
abstract: OBJECTIVE
  The aim of this study was to evaluate the pullout strength of 3 different orthodontic mini implants.
  
  
  METHODS
  Twenty-seven mini implants (diameter: 2 mm, length: 7 mm) were implanted into artificial bone (Sawbones; Pacific Research Laboratories Inc.) at depths of 3, 4, and 5 mm. The insertion torque (IT), resonance frequency (RF), pullout strength (PS), and anchor length (AL) were measured. One-way analysis of variance with Tukey honest significant difference (HSD) postcomparison were used to detect intergroup differences. The null hypothesis was that IT, RF, and PS would significantly correlate in the same brand.
  
  
  RESULTS
  In the implantation depths (ID) (5 and 4 mm), IT of Types C (16.67 and 14.33 N·cm) and Type B (14 and 13.33 N·cm) were significantly higher than Type A (10.33 and 9.33 N·cm). Type A had a largest AL and PS at the IDs (5 and 4 mm). In the IDs (3 mm), PS was no different. Type C had no correlation among the RF, IT, and PS. Therefore, null hypothesis was rejected.
  
  
  CONCLUSIONS
  AL exerted crucial effects on the PS of the mini implants.
authors.affiliation: *Assistant Professor, School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan. †Assistant Professor, Department of Orthodontics, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan. ‡Assistant Professor, Faculty of Oral Hygiene, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan. §Professor, School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan. ¶Professor, Department of Oral and Maxillofacial Surgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
authors.forename: Yu-Chuan
authors.initials: YC
authors.lastname: Tseng
authors.forename: Chun-Chan
authors.initials: CC
authors.lastname: Ting
authors.forename: Ju-Hui
authors.initials: JH
authors.lastname: Wu
authors.forename: Hong-Sen
authors.initials: HS
authors.lastname: Chen
authors.forename: Chun-Ming
authors.initials: CM
authors.lastname: Chen
mesh_terms: D001696:Biomechanical Phenomena; D040761:Biomimetic Materials; D015921:Dental Implants; D003799:Dental Stress Analysis; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D052280:Orthodontic Anchorage Procedures; D016382:Orthodontic Appliance Design; D013314:Stress, Mechanical; D013499:Surface Properties
chemical_list: D015921:Dental Implants