Effect of Mini-implant Diameters on Primary Stability and Viscoelastic Migration of Mini-implants under Orthodontic Loading

Objectives The objectives of the current study were to examine effects of mini-implant diameters on 1) primary stability and 2) time-dependent migration of mini-implant systems under a tangential loading.Materials and Methods Twenty one mini-implants (7 for each 1.4 mm, 1.6 mm, and 2 mm diameter mini-implant) were placed in mandibular sections of human cadavers (4 males and 3 females, 69.7+/-13.1 years). All mini-implants were 8 mm in length. A tangential load of 2N was applied to the mini-implant in bone under hydration for 2 hours. Migration was assessed as the change in displacement during initial loading followed by 2 hours constant loading. Mean and standard deviation (SD) of bone mineral density (BMD) were obtained using histogram of cone-beam computed tomography (CBCT) attenuation values surrounding the mini-implant hole. The cortical thickness along with the miniscrew hole was also measured using the CBCT image. Results The mini-implant diameters did not have an effect on determining the primary stability and migration of mini-implant (p=0.147). Positive correlations of migration with SD and COV were found (p=0.073). These correlations were independent of the mini-implant diameters (ANCOVA, p=0.11). Conclusions Time-dependent viscoelastic creep migration following the static displacement at the small level of orthodontic constant loading suggested that more complications may be produced due to the micromotion at the immediate loading after implantation.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Dentistry

Grantor dc:publisher

The Ohio State University

Year dc:date

2013

Author dc:creator

• Lee, Jim Ming-An

Contributors dc:contributor

• Kim, Do-Gyoon

• Dentistry
• miniscrews
• miniimplants
• viscoelasticity
• migration

Statement dc:rights

• unrestricted
• This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.

Language dc:language

English

Repository record dc:identifier

http://rave.ohiolink.edu/etdc/view?acc_num=osu1365079269

OAI identifier oai:identifier

oai:etd.ohiolink.edu:osu1365079269