Document Type : Original Article


Department of Orthodontics and Dentofacial Orthopaedics, The Oxford Dental College, Bengaluru, Karnataka, India


Aim: This study evaluated the effect of physical and chemical sterilization techniques on the fracture resistance of mini-implants.
Methods: Thirty-two titanium mini-implants of 1.5 x 8 mm were randomly divided into four groups: control, steam sterilized, dry heat sterilized, and chemically sterilized. The samples were then tested in the air for fracture resistance using a universal testing machine. A tangential load was applied to the head of the mini-implant with a 1 mm/min crosshead speed after blocking each of them in the machine. Also, the maximum load was recorded previous to screw fracture. he Kruskal-Wallis test and Mann-Whitney post hoc test were used for data analysis.
Results: The results of this study demonstrated the mean fracture resistance difference between the four groups was statistically significant at p<0.001. Moreover it was showed the control group had significantly higher mean fracture resistance compared to dry heat and chemically sterilized groups at p=0.001 and p=0.009 respectively. This was followed by the stem sterilized group demonstrating significantly higher mean fracture resistance as compared to dry heat and chemically sterilized groups at p=0.001 and p=0.01 respectively. Later, the chemically sterilized group also showed significantly higher mean fracture resistance as compared to the dry heat group at p=0.002. However, no significant difference was observed between the control and stem sterilized groups (p=0.29).
Conclusion: The steam sterilized group demonstrated the highest fracture resistance that was followed by the chemically sterilized group, and the least with the dry heat sterilized group.


Main Subjects

  1. DH ZhengFC Hou, YJ Zang & B Li. Effects of low-level laser therapy on orthodontic miniscrew stability: a systematic review. Eur J Med Res 2023 Jan 27;28(1):50.
  2. Loss T.F.A, Kitahara F.M.F, Silveira G.S. Fracture strength of orthodontic mini-implants. Dental Press J Orthod. May-June 2017;22(3):47-54. DOI: 1590/2177-6709.22.3.047-054.oar.
  3. SE Barros, G Janson, K Chiqueto, DG Garib, M Janson Effect of mini-implant diameter on fracture risk and self drilling efficacy. Am J Orthod Dentofacial Orthop 2011 OCT; 14(4), 181-192. https://pubmed.ncbi.nlm.nih. gov/21967956/.
  4. Scribante A, Montasser M.A, Radwan E.S, Bernardinelli L, Alcozer R, Gandini P, et. al. Reliability of orthodontic miniscrews: bending and maximum load of different Ti-6Al-4V titanium and stainless-steel temporary anchorage devices (TADs). Materials (Basel) 2018 Jul; 11(7):1138. doi: 3390/ma11071138.
  5. Alavi S, Asadi F, Raji S.A, Samie S. Effect of steam and dry heat sterilization on the insertion and fracture torque of orthodontic miniscrews. Dent Res J (Isfahan) 2020 May 1;17(3):219. DOI:4103/1735-3327.284729
  6. Manni A, Cozzani M, Tamborrino F. Factors influencing the stability of miniscrews. A retrospective study on 300 miniscrews. Eur. J. Orthod. 2011; 33, 388–395. DOI: 1093/ejo/cjq090.
  7. Hergel C.A, Acar Y.B, Ateş M. In-vitro evaluation of the effects of insertion and sterilization procedures on the mechanical and surface characteristics of mini-screws. Eur.Oral.Res. 2019; 53(1): 25-31. doi: 26650/eor. 20197993.
  8. Lim S.A, Cha J.Y, Hwang C.J. Insertion Torque of Orthodontic Miniscrews According to Changes in Shape, Diameter and Length. Angle Orthod, 2008;78 (2), 234-240. DOI: 2319/121206-507.1.
  9. Alavi S, Mousavi S.M, Shirban F. Effect of Heat Sterilization on the Load/Deflection of Heat-activated Orthodontic Wires. Orthod. J. Nepal, December 2014; 4(2), 24-27. doi: 4103/1735-3327.104871.
  10. Yadav A, Jayaprakash P.K, Singh R, Dawer M, Modi P, Sehdev B, et. al. Impact of recycling on the mechanical properties of nickel-titanium alloy wires and the efficacy of their reuse after cold sterilization. J Orthod Sci 2020;9. DOI: 4103/jos.JOS_45_19.
  11. W Rerhrhaye, B Ouaki, F Zaoui, E Aalloula The effect of autoclave sterilization on the surface properties of orthodontic brackets after fitting in the mouth Odontostomatol Trop 2011 Dec;34(136):29-34. https://
  12. G Jasoria, W Shamim, S Rathore A Kalra, M Manchanda, N Jaggi. Miniscrew implants as temporary anchorage devices in orthodontics: A comprehensive review. J Contemp Dent Pract 2013 Sep 1;14(5):993-9.
  13. Brindha M, Kumaran N.K, Rajasigamani K. Evaluation of tensile strength and surface topography of orthodontic wires after infection control procedures: An in vitro study. J. Pharm. Bioallied Sci. July 2014;6(1),44-48. doi: 4103/0975-7406.137386.
  14. R Suresh, P Kalidas Effects of Autoclave Sterilization on the Surface Parameters and Mechanical Properties of Different Composition of Five Orthodontic Arch Wires – An in Vitro Study. J. Contemp. Dent 2020; 8(1), 36-42.
  15. A Ardeshna, K Chavan, A Prakasam Effectiveness of different sterilization methods on clinical orthodontic materials. J Indian Orthod Soc 2023 Apr; 57(2), 98-105.
  16. Brown RN, Sexton BE. Comparison of stainless steel and titanium alloy orthodontic miniscrew implants: a mechanical and histologic analysis. Am J Orthod Dentofacial Orthop. 2014; 145:496–504. https://
  17. Z Gurdan, J Szalma. Evaluation of the success and complication rates of self-drilling orthodontic mini-implants. Niger J Clin Pract 2018 May;21(5):546-552.
  18. Yu WP, Yu JH, Wang SH & Hsu JT  The Effects of Diameter, Length and Insertion Method on the Stability of Orthodontic Miniscrew. J. Med. Biol. Eng. 2022; 42, 508–515. s40846-022-00737-0.
  19. Mattos C.T, Ruellas A.C, Sant'Anna E.F. Effect of autoclaving on the fracture torque of mini‐implants used for orthodontic anchorage. J Orthod 2011 Mar;38(1):15-20. DOI: 1179/14653121141200.
  20. Dalla Rosa F, Burmann P.F, Ruschel H.C. Evaluation of fracture torque resistance of orthodontic mini‑implants. Acta Odontol Latinoam 2016; 29:248‑54. https://
  21. BuckthalE, Kusy R.P Effects of cold disinfectants on the mechanical properties and the surface topography of nickel titanium arch wires. Am J Orthod Dentofacial Orthop 1988 Aug;94(2):117-22. DOI: 10.1016/0889-5406(88)90359-9.
  22. Pop S.I, Bratu D.C, Chiorean R. Biochemical Characteristics of Mini-implants Sterilised by Different Chemical and Physical Procedures. Materiale Plastice, 2017; 54(2):253-256. https://revmaterialeplastice. ro/pdf/12%20POP%20IZABELA%202%2017.pdf.
  23. Adelson R.T, Defatta R.J, Ducic Y. Integrity of craniofacial plating systems after multiple sterilization procedures. J Oral Maxillofac Surg 2007; 65: 940–44. DOI: 1016/j.joms.2005.12.059.
  24. Testarelli L, Gallottini L, Gambarini G. Mechanical properties of nickel‑titanium files following multiple heat sterilizations. Minerva Stomatol 2003; 52:169‑73.
  25. Silvaggio J, Hicks M.L. Effect of heat sterilization on the torsional properties of rotary nickel‑titanium endodontic files. J Endod 1997; 23:731‑4. DOI: 1016/ S0099-2399(97)80344-5.
  26. J E Buckthal, R P Kusy. Effects of cold disinfectants on the mechanical properties and the surface topography of nickel-titanium arch wires. Am J Orthod Dentofacial Orthop 1988 Aug;94(2):117-22. https://pubmed.ncbi.