Korean J Orthod.  2010 Jun;40(3):167-175. 10.4041/kjod.2010.40.3.167.

The validation of Periotest values for the evaluation of orthodontic mini-implants' stability

• Cha JY
• Yu HS
• Hwang CJ

• KMID: 1459570
• DOI: http://doi.org/10.4041/kjod.2010.40.3.167

Abstract

OBJECTIVE
The aim of this study was to validate the Periotest values for the prediction of orthodontic mini-implants' stability.
METHODS
Sixty orthodontic mini-implants (7.0 mm x O1.45 mm; ACR, Biomaterials Korea, Seoul, Korea) were inserted into the buccal alveolar bone of 5 twelve month-old beagle dogs. Insertion torque (IT) and Periotest values (PTV) were measured at the installation procedure, and removal torque (RT) and PTV were recorded after 12 weeks of orthodontic loading. To correlate PTV with variables, the cortical bone thickness (mm) and bone mineral density (BMD) within the cortical bone and total bone area were calculated with the help of CT scanning.
RESULTS
The BMD and cortical bone thickness in mandibular alveolus were significantly higher than those of the maxilla (p< 0.05). The PTV values ranged from -3.2 to 4.8 for 12 weeks of loading showing clinically stable mini-implants. PTV at insertion was significantly correlated with IT (-0.51), bone density (-0.48), cortical bone thickness (-0.42) (p< 0.05) in the mandible, but showed no correlation in the maxilla. PTV before removal was significantly correlated with RT (-0.66) (p< 0.01) in the mandible.
CONCLUSIONS
These results show that the periotest is a useful method for the evaluation of mini-implant stability, but it can only be applied to limited areas with thick cortical and high density bone such as the mandible.

Keyword

Periotest; Orthodontic mini-implants; Insertion torque; Mobility

MeSH Terms

Animals
Biocompatible Materials
Bone Density
Dogs
Korea
Mandible
Maxilla
Torque
Biocompatible Materials