Primary stability of microscrews based on their diameter, length, shape and area of insertion. an experimental study with Periotest.
BACKGROUND
The high number of publications about microscrews is an evidence of their clinical success. Many authors recommend specific microscrews, diameter, length, shape and site of insertion for each case, nevertheless there is no scientific evidence to support those recommendations.


OBJECTIVE
The aim of this study was to quantify the primary stability of microscrews using Periotest and evaluate the influence of diameter, length and shape in their primary stability. Material and methods. Seventy-two microscrews with different lengths, diameters and shapes were inserted into 6 lamb heads. Their primary stability was quantified using Periotest. The data analysis was carried out by the Statgraphics Plus software.


RESULTS
There were no statistical significant differences in the primary stability values of microscrews based on their diameter and length. But regarding to shape, conical microscrews provided more primary stability than cylindrical ones.


CONCLUSIONS
Neither the length ( 8 mm vs. 10 mm) nor the diameter (1.6 mm vs 2 mm) influences the primary stability of microscrews. When selecting the dimensions of microscrews for each case there are other factors to evaluate like cortical bone thickness. Conical microscrews provide more primary stability than cylindrical ones in lamb bone.
Maria
Orquin
O
Department of Orthodontics and Dentofacial Orthopedics - Universitat Internacional de Catalunya, Barcelona, Spain. morquin@ortodoncianovasmile.com
Ana
Molina
M
Andreu
Puigdollers
P
D000818:Animals; D001863:Bone Screws; D008437:Maxilla / Q000033:anatomy & histology / Q000601:surgery; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation*; D016382:Orthodontic Appliance Design; D016348:Osseointegration / Q000502:physiology; D010517:Periodontics / Q000295:instrumentation; D012756:Sheep; D013499:Surface Properties