Skip to main content
SpringerLink
Log in

Experimental investigation of the fracture torque of orthodontic anchorage screws

Experimentelle Untersuchungen zum Bruchdrehmoment kieferorthopädischer Minischrauben

  • Original Article
  • Published:
Journal of Orofacial Orthopedics / Fortschritte der Kieferorthopädie Aims and scope Submit manuscript

Abstract

Objectives

In contrast to dental implants that remain in the bone, orthodontic anchorage screws serve as temporary anchorage for orthodontic tooth movement and are removed after completion of treatment. The aim of the present study was to evaluate the stability of various commercially available orthodontic anchorage screws against torsion.

Materials and methods

The torsional deflection of ten different orthodontic anchorage screws from different manufacturers [Ortho Easy Pin (Forestadent), Benefit, quattro (both PSM Medical Solutions), Vector TAS (Ormco), AbsoAnchor® (DENTOS Inc.), OrthoLox, Dual-Top JA (both Promedia Medizintechnik), TAD (3M Unitek), INFINITAS (ODS) and tomas® (Dentaurum)] was tested in vitro in relation to the rotation angle using a self-developed set-up. The screws were positioned in a resin model with bone-like material properties. Shear tests were performed using the manufacturers’ own screwdrivers. Ten screws each were turned manually until a sudden drop in the measured torque occurred. At this point, the screw head was twisted off. Fracture torque and the torque at which the screws deformed plastically were evaluated. Mean values and standard deviations were calculated.

Results

According to the German industrial standard, the torque of orthodontic anchorage screws should reach at least 20 Ncm. The majority of the screws reached this nominal torque; however, a few screws fractured before reaching this value. Five screw types displayed plastic deformation below the threshold, at approximately 16 Ncm.

Conclusions

The results suggest that orthodontic anchorage screws generally meet the requirements of the standard and ensure safe clinical use. However, according to the present data, it may be assumed that a portion of the screws will be plastically deformed upon removal.

Zusammenfassung

Hintergrund und Ziel

Im Unterschied zu Dentalimplantaten, die dauerhaft im Knochen verbleiben sollen, werden orthodontische Minischrauben zum Ende der Behandlung entfernt. Ziel der vorliegenden Studie war es, die Stabilität verschiedener kommerzieller Minischrauben bei Torsion zu beurteilen.

Material und Methodik

Die Verformung unter Torsionsbelastung von 10 verschiedenen orthodontischen Minischrauben unterschiedlicher Hersteller [Ortho Easy Pin (Forestadent), Benefit, quattro (beide PSM Medical Solutions), Vector TAS (Ormco), AbsoAnchor® (DENTOS Inc.), OrthoLox, Dual-Top JA (beide Promedia Medizintechnik), TAD (3M Unitek), INFINITAS (ODS) und tomas® (Dentaurum)] wurden in vitro im Verhältnis zum Drehwinkel in einer selbstentwickelten Apparatur geprüft. Die Minischrauben wurden in einem Kunststoff mit knochenähnlichen Eigenschaften eingebettet. Die Abscherversuche erfolgten mit herstellereigenem Werkzeug. Jeweils 10 Schrauben wurden von Hand gedreht, bis ein plötzlicher Abfall des gemessenen Drehmoments auftrat. An diesem Punkt wurde der Schraubenkopf abgedreht. Ausgewertet wurden das Bruchdrehmoment und das Drehmoment, an dem sich die Schrauben plastisch verformten (Fließdrehmoment), ermittelt wurden Mittelwerte und Standardabweichungen.

Ergebnisse

Laut DIN 13997 soll das Abdrehmoment kieferorthopädischer Minischrauben mindestens 20 Ncm erreichen. Der überwiegende Teil der Minischrauben erreichte dieses Nenndrehmoment, nur wenige brachen vorher ab. Fünf Minischrauben zeigten plastische Verformungen unterhalb dieser Schwelle, ungefähr bei 16 N.

Schlussfolgerungen

In der Regel erfüllen kieferorthopädische Minischrauben die Anforderungen nach DIN 13997, sodass eine sichere klinische Anwendung gegeben ist. Doch gemäß den vorliegenden Daten ist davon auszugehen, dass ein Teil der Schrauben beim Entfernen plastisch deformiert wird.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5

Similar content being viewed by others

References

  1. Carano A, Lonardo P, Velo S et al (2005) Mechanical properties of three different commercially available miniscrews for skeletal anchorage. Prog Orthod 6:82–97

    PubMed  Google Scholar 

  2. Chaddad K, Ferreira A, Geurs N et al (2008) Influence of surface characteristics on survival rates of mini-implants. Angle Orthod 78:107–113

    Article  PubMed  Google Scholar 

  3. Chen CH, Chang CS, Hsieh Ch et al (2006) The use of microimplants in orthodontic anchorage. J Oral Maxillofac Surg 64:1209–1213

    Article  PubMed  Google Scholar 

  4. Standard DIN 13997:2012-10 (D) Zahnheilkunde - Kieferorthopädische Minischrauben. Dentistry — Orthodontic miniscrews

  5. Favero L, Pisoni A, Paganelli C (2007) Removal torque of osseointegrated mini-implants: an in vivo evaluation. Eur J Orthod 29:443–448

    Article  PubMed  Google Scholar 

  6. Frost HM (2004) A 2003 update of bone physiology and Wolff‘s Law for clinicians. Angle Orthod 74:3–15

    PubMed  Google Scholar 

  7. Frost HM (1990) Skeletal structural adaptations to mechanical usage (SATMU): 1. Redefining Wolff’s Law: the bone modeling problem. Anat Rec 226:403–413

    Article  PubMed  Google Scholar 

  8. Jolley T, Chung C (2007) Peak torque values at fracture of orthodontic miniscrews. J Clin Orthod 41:326–328

    PubMed  Google Scholar 

  9. Kim S, Cho J, Chung K et al (2008) Removal torque values of surface-treated mini-implants after loading. Am J Orthod Dentofacial Orthop 134:36–43

    Article  PubMed  Google Scholar 

  10. Kravitz N, Kusnoto B (2007) Risks and complications of orthodontic miniscrews. Am J Orthod Dentofacial Orthop 131:43–51

    Article  Google Scholar 

  11. Lietz T (2008) Mini-screws: aspects of assessment and selection among different systems. In: Ludwig B, Baumgaertel S, Bowman J (eds) Mini-implants in orthodontics. Quintessence, London, pp 11–72

    Google Scholar 

  12. Lima G, Soares M, Penha S et al (2011) Comparison of the fracture torque of different Brazilian mini-implants. Br Oral Res 25:116–121

    Article  Google Scholar 

  13. Melsen B, Costa A (2000) Immediate loading of implants used for orthodontic anchorage. Clin Orthod Res 3:23–28

    Article  PubMed  Google Scholar 

  14. Melsen B, Verna C (2005) Miniscrew implants: the Aarhus anchorage system. Semin Orthod 11:24–31

    Article  Google Scholar 

  15. Meursinge Reynders RA, Ronchi L, Ladu L et al (2012) Insertion torque and success of orthodontic mini-implants: a systematic review. Am J Orthod Dentofacial Orthop 142:596–614

    Article  PubMed  Google Scholar 

  16. Okazaki J, Komasa Y, Sakai D et al (2008) A torque removal study on the primary stability of orthodontic titanium screw mini-implants in the cortical bone of dog femurs. Int J Oral Maxillofac Surg 37:647–650

    Article  PubMed  Google Scholar 

  17. Papadopoulos MA, Tarawneh F (2007) The use of miniscrew implants for temporary skeletal anchorage in orthodontics: a comprehensive review. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 103:e6–e15

    Article  PubMed  Google Scholar 

  18. Reicheneder C, Rottner K, Bokan I et al (2008) Mechanical loading of orthodontic miniscrews-significance and problems: an experimental study. Biomed Tech (Berl) 53:242–245

    Article  Google Scholar 

  19. Schaffler MB, Radin EL (1985) Bone remodeling in response to in vivo fatigue microdamage. J Biomech 18:189–200

    Article  PubMed  Google Scholar 

  20. Suzuki E, Suzuki B (2011) Placement and removal torque values of orthodontic miniscrew implants. Am J Orthod Dentofacial Orthop 139:669–678

    Article  PubMed  Google Scholar 

  21. Vande Vannet B, Sabzevar M, Wehrbein H et al (2007) Osseointegration of miniscrews: a histomorphometric evaluation. Eur J Orthod 29:437–442

    Article  PubMed  Google Scholar 

  22. Wawrzinek C, Sommer T, Fischer-Brandies H (2008) Microdamage in cortical bone due to the over-tightening of orthodontic microscrews. J Orofac Orthop 69:121–134

    Article  PubMed  Google Scholar 

  23. Wehrbein H, Göllner P (2007) Skeletal anchorage in orthodontics: basics and clincal application. J Orofac Orthop 68:443–461

    Article  PubMed  Google Scholar 

  24. Wilmes B, Panayotidis A, Drescher D (2011) Fracture resistance of orthodontic mini-implants: a biomechanical in vitro study. Eur J Orthod 33:396–401

    Article  PubMed  Google Scholar 

Download references

Acknowledgments

The authors wish to thank the companies for providing the materials.

Author information

Authors and Affiliations

  1. Department of Orthodontics, University of Bonn, Bonn, Germany

    Susanne Reimann, Mustafa Ayubi & Christoph Bourauel

  2. Department of Orthodontics and Craniofacial Development, Kings College London, London, UK

    Fraser McDonald

  3. Endowed Chair for Oral Technology, Rheinische Friedrich-Wilhelms University of Bonn, Welschnonnenstrasse 17, 53111, Bonn, Germany

    Susanne Reimann

Authors
  1. Susanne Reimann
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Mustafa Ayubi
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Fraser McDonald
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Christoph Bourauel
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Susanne Reimann.

Ethics declarations

Conflict of interest

S. Reimann, M. Ayubi, F. McDonald, and C. Bourauel state that there are no conflicts of interest.

The accompanying manuscript does not include studies on humans or animals.

Additional information

Dr. rer. nat. Susanne Reimann.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Reimann, S., Ayubi, M., McDonald, F. et al. Experimental investigation of the fracture torque of orthodontic anchorage screws. J Orofac Orthop 77, 272–280 (2016). https://doi.org/10.1007/s00056-016-0032-6

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00056-016-0032-6

Keywords

Schlüsselwörter

Search

Navigation