Korean J Orthod.  2012 Feb;42(1):4-10.

Effect of surface anodization on stability of orthodontic microimplant

• Karmarker
• Yu W
• Kyung HM

Abstract

OBJECTIVE
To determine the effect of surface anodization on the interfacial strength between an orthodontic microimplant (MI) and the rabbit tibial bone, particularly in the initial phase after placement.
METHODS
A total of 36 MIs were driven into the tibias of 3 mature rabbits by using the self-drilling method and then removed after 6 weeks. Half the MIs were as-machined (n = 18; machined group), while the remaining had anodized surfaces (n = 18; anodized group). The peak insertion torque (PIT) and the peak removal torque (PRT) values were measured for the 2 groups of MIs. These values were then used to calculate the interfacial shear strength between the MI and cortical bone.
RESULTS
There were no statistical differences in terms of PIT between the 2 groups. However, mean PRT was significantly greater for the anodized implants (3.79 +/- 1.39 Ncm) than for the machined ones (2.05 +/- 1.07 Ncm) (p < 0.01). The interfacial strengths, converted from PRT, were calculated at 10.6 MPa and 5.74 MPa for the anodized and machined group implants, respectively.
CONCLUSIONS
Anodization of orthodontic MIs may enhance their early-phase retention capability, thereby ensuring a more reliable source of absolute anchorage.

Keyword

Orthodontic microimplant; Anodization; Self drilling; Interfacial shear strength

MeSH Terms

Rabbits
Retention (Psychology)
Shear Strength
Tibia
Torque

Figure

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  Figure 1 Tapered-type Absoanchor® microimplants (SH1312-06). A, machined-surface implant (left), anodized-surface implant (right); B and C, Scanning electron micrograph of an implant (×1,500) with a machined surface (B) and an anodized surface (C).

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  Figure 2 Placement of microimplants in the rabbit tibia. White circle indicates anodized implant.

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  Figure 3 Dimensions of an Absoanchor® microimplant (SH1312-6). d, core diameter (0.8 mm); h, screw height (0.25 mm); g, gap between thread (0.22 mm); b, screw base (0.28 mm); pitch, b + g (0.5 mm).

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  Figure 4 Comparison of the magnitude of insertion and removal torque for individual implants in the machined group.

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  Figure 5 Comparison of the magnitude of insertion and removal torque for individual implants in the anodized group.

Reference

1. Park HS, Bae SM, Kyung HM, Sung JH. Micro-implant anchorage for treatment of skeletal Class I bialveolar protrusion. J Clin Orthod. 2001. 35:417–422.

2. Bae SM, Park HS, Kyung HM, Kwon OW, Sung JH. Clinical application of micro-implant anchorage. J Clin Orthod. 2002. 36:298–302.

3. Kyung HM, Park HS, Bae SM, Sung JH, Kim IB. Development of orthodontic micro-implants for intraoral anchorage. J Clin Orthod. 2003. 37:321–328.

4. Kuroda S, Sugawara Y, Deguchi T, Kyung HM, Takano-Yamamoto T. Clinical use of miniscrew implants as orthodontic anchorage: success rates and postoperative discomfort. Am J Orthod Dentofacial Orthop. 2007. 131:9–15.

5. Baek SH, Kim BM, Kyung SH, Lim JK, Kim YH. Success rate and risk factors associated with mini-implants reinstalled in the maxilla. Angle Orthod. 2008. 78:895–901.

6. Wu TY, Kuang SH, Wu CH. Factors associated with the stability of mini-implants for orthodontic anchorage: a study of 414 samples in Taiwan. J Oral Maxillofac Surg. 2009. 67:1595–1599.

7. Kim SH, Lee SJ, Cho IS, Kim SK, Kim TW. Rotational resistance of surface-treated mini-implants. Angle Orthod. 2009. 79:899–907.

8. Jeon MS, Kang YG, Mo SS, Lee KH, Kook YA, Kim SH. Effects of surface treatment on the osseointegration potential of orthodontic mini-implant. Korean J Orthod. 2008. 38:328–336.

9. Shibli JA, Grassi S, de Figueiredo LC, Feres M, Marcantonio E Jr, Iezzi G, et al. Influence of implant surface topography on early osseointegration: a histological study in human jaws. J Biomed Mater Res B Appl Biomater. 2007. 80:377–385.

10. Ivanoff CJ, Widmark G, Johansson C, Wennerberg A. Histologic evaluation of bone response to oxidized and turned titanium micro-implants in human jawbone. Int J Oral Maxillofac Implants. 2003. 18:341–348.

11. Kieswetter K, Schwartz Z, Dean DD, Boyan BD. The role of implant surface characteristics in the healing of bone. Crit Rev Oral Biol Med. 1996. 7:329–345.

12. Cordioli G, Majzoub Z, Piattelli A, Scarano A. Removal torque and histomorphometric investigation of 4 different titanium surfaces: an experimental study in the rabbit tibia. Int J Oral Maxillofac Implants. 2000. 15:668–674.

13. Thomas KA, Kay JF, Cook SD, Jarcho M. The effect of surface macrotexture and hydroxylapatite coating on the mechanical strengths and histologic profiles of titanium implant materials. J Biomed Mater Res. 1987. 21:1395–1414.

14. Li D, Ferguson SJ, Beutler T, Cochran DL, Sittig C, Hirt HP, et al. Biomechanical comparison of the sandblasted and acid-etched and the machined and acid-etched titanium surface for dental implants. J Biomed Mater Res. 2002. 60:325–332.

15. Cho SA, Jung SK. A removal torque of the laser-treated titanium implants in rabbit tibia. Biomaterials. 2003. 24:4859–4863.

16. Sul YT. The significance of the surface properties of oxidized titanium to the bone response: special emphasis on potential biochemical bonding of oxidized titanium implant. Biomaterials. 2003. 24:3893–3907.

17. Son WW, Zhu X, Shin HI, Ong JL, Kim KH. In vivo histological response to anodized and anodized/hydrothermally treated titanium implants. J Biomed Mater Res B Appl Biomater. 2003. 66:520–525.

18. Sul YT, Johansson CB, Jeong Y, Wennerberg A, Albrektsson T. Resonance frequency and removal torque analysis of implants with turned and anodized surface oxides. Clin Oral Implants Res. 2002. 13:252–259.

19. Jungner M, Lundqvist P, Lundgren S. Oxidized titanium implants (Nobel Biocare TiUnite) compared with turned titanium implants (Nobel Biocare mark III) with respect to implant failure in a group of consecutive patients treated with early functional loading and two-stage protocol. Clin Oral Implants Res. 2005. 16:308–312.

20. Suh JY, Jang BC, Zhu X, Ong JL, Kim K. Effect of hydrothermally treated anodic oxide films on osteoblast attachment and proliferation. Biomaterials. 2003. 24:347–355.

21. Roberts WE, Smith RK, Zilberman Y, Mozsary PG, Smith RS. Osseous adaptation to continuous loading of rigid endosseous implants. Am J Orthod. 1984. 86:95–111.

22. Esposito M, Hirsch JM, Lekholm U, Thomsen P. Biological factors contributing to failures of osseointegrated oral implants. (I). Success criteria and epidemiology. Eur J Oral Sci. 1998. 106:527–551.

23. Olmedo D, Fernández MM, Guglielmotti MB, Cabrini RL. Macrophages related to dental implant failure. Implant Dent. 2003. 12:75–80.

24. Sánchez-Gárces MA, Gay-Escoda C. Periimplantitis. Med Oral Patol Oral Cir Bucal. 2004. 9:Suppl. 69–74. 63–69.

25. Zhu X, Kim K, Ong JL, Jeong Y. Surface analysis of anodic oxide films containing phosphorus on titanium. Int J Oral Maxillofac Implants. 2002. 17:331–336.

26. Zhu X, Ong JL, Kim S, Kim K. Surface characteristics and structure of anodic oxide films containing Ca and P on a titanium implant material. J Biomed Mater Res. 2002. 60:333–338.

27. Larsson C, Emanuelsson L, Thomsen P, Ericson LE, Aronsson BO, Kasemo B, et al. Bone response to surface modified titanium implants - studies on the tissue response after 1 year to machined and electropolished implants with different oxide thicknesses. J Mater Sci Mater Med. 1997. 8:721–729.

28. Frost HM. A 2003 update of bone physiology and Wolff's Law for clinicians. Angle Orthod. 2004. 74:3–15.

29. Motoyoshi M, Hirabayashi M, Uemura M, Shimizu N. Recommended placement torque when tightening an orthodontic mini-implant. Clin Oral Implants Res. 2006. 17:109–114.

30. Kim JW, Ahn SJ, Chang YI. Histomorphometric and mechanical analyses of the drill-free screw as orthodontic anchorage. Am J Orthod Dentofacial Orthop. 2005. 128:190–194.

31. Sul YT, Johansson CB, Kang Y, Jeon DG, Albrektsson T. Bone reactions to oxidized titanium implants with electrochemical anion sulphuric acid and phosphoric acid incorporation. Clin Implant Dent Relat Res. 2002. 4:78–87.

32. Sul YT, Johansson CB, Albrektsson T. Oxidized titanium screws coated with calcium ions and their performance in rabbit bone. Int J Oral Maxillofac Implants. 2002. 17:625–634.

33. Morais LS, Serra GG, Muller CA, Andrade LR, Palermo EF, Elias CN, et al. Titanium alloy mini-implants for orthodontic anchorage: immediate loading and metal ion release. Acta Biomater. 2007. 3:331–339.