The Effect of Time on Orthodontic Mini-Screw Implants Stability (An experimental study)

Hassan Moyasser Dawood Al-Nuaimy, Hussein Ahmad Jasim Al-Obaidy


Background: Mini-screw implants have become an accepted and reliable method for providing orthodontic anchorage. The present
study aimed to measure the primary and secondary stability of mini-screw implants using the removal torque value as indictor for
the stability and comparing between four different periods of mini-screw implants removal (Immediate, 2 weeks, 4 weeks and 6
Materials and Methods: Forty mini-screw implants, all of the same manufacture, length (7 mm), diameter (1.4 mm) and of cylinder
type, were implanted in the tibia bone of two sheep (ten in each tibia) after anesthesia and flap reflection using drilling burs. The
insertion torque were standardized and equalized for all mini-screws. Mini-screw implants were removed after different periods
of time (immediately, 2 weeks, 4 weeks and 6 weeks) using digital torque screw driver (DID-4). One-way ANOVA test was used to
compare among the groups.
Results: The results showed that mini-screw implants stability significantly decreased during the first two weeks then started to
increase during the four and six weeks.
Conclusions: It was concluded from this study that mini-screw implants stability is affected by the period of implantation, decreased
during the first two weeks and then started to increase.


MSI (Mini-screw implant); DID4 (digital insertion torque screw driver; Stability; Torque


Park H, Jeong S, Kwon O. Factors affecting the clinical

success of screw implants used as orthodontic anchorage.

Am J Orthod Dentofac Orthop. 2006; 130: 18–25.

Buschang PH, Carrillo R, Ozenbaugh B, Rossouw PE.

Survey of AAO members on mini-screw usage. J Clin

Orthod. 2008; 42: 513–8.

Reynders R, Ronchi L, Bipat S. Mini-implants in orthodontics;

a systematic review of the literature. Am J Orthod Dentofac

Orthop. 2009; 135: 564.

Branemark PI, Aspegren K, Breine U. Microcirculatory

studies in man by high resolution vital microscopy.

Angiology. 1964; 15: 329-32.

Branemark PI, Breine U, Adell R. Intraosseous anchorage

of dental prostheses. I. Experimental studies. Scand J Plast

Reconstr Surg. 1969; 3: 81-100.

Sakin Ç, Aylikci Ö. Techniques to measure miniscrew implant

stability. J Orthod Res. 2013; 1: 5-10.

Meredith N. Assessment of implant stability as a prognostic

determinant. Int J Prosthodont. 1998; 11: 491-501.

Roberts W, Smith R, Zilberman Y, et al. Osseous adaptation

to continuous loading of rigid endosseous implants. Am J

Orthod. 1984; 86: 95-111.

Johansson C, Albrektsson T. A removal torque and

histomorphometric study of commercially pure niobium

and titanium implants in rabbit bone. Clin Oral Implants

Res. 1991; 2(2): 4-9.

h t t p : / / w w w. c a l s . n c s u . e d u / a n _ s c i / e x t e n s i o n /

a n i m a l / 4 h y o u t h / s h e e p / s h e e p f a c t s . h t m .

Agfact A. Division of Animal Production Reviewed. 2003;

(1): 2.

Kott K, Church B, Jurgens A. Sheep Nutrition and Feeding.

Animal Nutrition Handbook. 2009; 16: 426-46.

Sharawy M, Carl E, Weller N, Tehemar S. Heat generation

during implant drilling: The significance of motor speed. J

Oral Maxillofac Surg 2002; 60: 1168.

Motoyoshi M, Yoshida T, Ono A, Shimizu N. Effect of

cortical bone thickness and implant placement torque on

stability of orthodontic mini-implants. Int J Oral Maxillofac

Implants. 2007; 22(7): 79-84.

Schorlemmeret S, et al. Inhibition of cortical and cancellous

bone formation in glucocorticoid-treated OVX sheep.

Bone. 2005; 37: 493.

Christopher CK. Implants for the narrow edentulous site. J

Dental Practice. 2006; 3: 146.

Boronat López A, Balaguer Martínez J, Lamas Pelayo

J, et al. Resonance frequency analysis of dental implant

stability during the healing period. Med Oral Patol Oral Cir

Bucal. 2008; 13: E244-7.

Barewal RM, Oates TW, Meredith N, Cochran DL.

Resonance frequency measurement of implant stability

in vivo on implants with a sandblasted and acid-etched

surface. Int J Oral Maxillofac Implants. 2003; 18: 641-51.

Roberts WE. When planning to use an implant for

anchorage, how long do you have to wait to apply force

after implant placement? Am J Orthod Dentofac Orthop.

; 121(1): 14A.

Derid S. Evaluting stability changes of mini-screw implants

using resonance frequency analysis in beagle dogs,

University of Saint Louis. 2010; 100-9.



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