Initial and Fatigue Bond Strengths of Nanofilled and Conventional Composite Bonding Adhesives

Abstract

Aim

To compare the initial and fatigue shear bond strengths of a nanofilled adhesive with a conventional light-cured adhesive in an ex vivo laboratory study.

Methods

Fifty hydroxyapatite discs were prepared by cold pressing. Using a standardized bonding protocol, 100 Victory series upper left central incisor brackets were bonded to discs with Transbond™ Supreme LV nanofilled composite resin and 100 brackets were bonded to discs with Transbond XT. Fifty brackets from each group were subjected to cyclic loading (5000 cycles at 2 Hz) at 50% of the mean bond strength in a Dartec Series HC10 Testing Machine. Initial (unfatigued) and fatigued bond strengths were determined by applying a shear force at the bracket/substrate interface using a custom-made metal jig in an Instron Universal Testing Machine.

Results and statistical analysis

One-way analysis of variance showed that Transbond Supreme LV exhibited higher initial mean bond strength than Transbond XT (P = 0·001). No statistically significant difference was found between the fatigue bond strengths of Transbond Supreme LV and Transbond XT (P = 0·323). Two-way analysis of variance demonstrated statistically significant differences when the effect of the composite resin (P = 0·013) and fatigue (P = 0·017) were considered individually. However, when considered in combination there was no statistical significance (P = 0·09). Kaplan–Meier survival analysis showed superior survival of unfatigued brackets with Transbond Supreme LV, but there was no significant difference between the adhesives after fatiguing.

Conclusions

The initial bond strength of Transbond Supreme LV was significantly higher than Transbond XT, while the fatigue bond strengths of both resins were comparable. Overall, Transbond Supreme LV demonstrated superior survival under loading than Transbond XT. However, while this was statistically significant for the initial loading, it was not significant after fatiguing. Although these laboratory findings are useful as indicators of potential clinical performance, extrapolation of these results should be carried out with caution.

Keywords

Adhesives bond strength fatigue nanofilled resin

Get full access to this article

View all access options for this article.

References

Kirk

, Othmer

, Kroschwitz

, Howe-Grant

Encyclopedia of Chemical Technology, 4th Edn. New York: Wiley, 1991, 397.

Mitra

, Wu

, Holmes

. An application of nanotechnology in advanced dental materials. J Am Dent Assoc 2003; 134: 1382–90.

Beun

, Glorieux

, Devaux

, Vreven

, Leloup

Characterization of nanofilled compared to universal and microfilled composites. Dent Mater 2007; 23: 51–59.

Botta

, Duarte

Jr , Paulin Filho

, Gheno

, Powers

. Surface roughness of enamel and four resin composites. Am J Dent 2009; 22: 252–54.

de Moraes

, Gonçalves Lde

, Lancellotti

, Consani

, Correr-Sobrinho

, Sinhoreti

. Nanohybrid resin composites: nanofiller loaded materials or traditional mycrohybrid resins? Oper Dent 2009; 34: 551–57.

Imthiaz

, Georgiou

, Moles

, Jones

. Comparison of hydroxyapatite and dental enamel for testing shear bond strengths. Aust Orthod J 2008; 24: 15–20.

Jones

, Cheuk

, Georgiou

, Moles

. Comparison of flouridated apatites with pure hydroxyapatite as potential biomimetic alternatives to enamel for laboratory-based bond strength studies. Aust Orthod J 2009; 25: 12–18.

Klocke

, Tadic

, Kahl-Nieke

, Epple

An optimized synthetic substrate for orthodontic bond strength testing. Dent Mater 2003; 19: 773–78.

Fox

, McCabe

, Buckley

. A critique of bond strength testing in orthodontics. Br J Orthod 1994; 21: 33–43.

10.

Bishara

, Soliman

, Laffoon

, Warren

. Effect of changing a test parameter on the shear bond strength of orthodontic brackets. Angle Orthod 2005; 75: 832–35.

11.

Gwinnett

. Bonding of restorative resins to enamel. Int Dent J 1988; 38: 91–96.

12.

Lee

, Georgiou

, Jones

. Initial and fatigue bond strengths of chromatic and light-cured adhesives. Aust Orthod J 2010; 26: 119–26.

13.

Klocke

, Kahl-Nieke

Influence of cross-head speed in orthodontic bond strength testing. Dent Mater 2005; 21: 139–44.

14.

Tavas

, Watts

. Bonding of orthodontic brackets by transillumination of a light activated composite: an in vitro study. Br J Orthod 1979; 6: 207–08.

15.

Lopez

. Retentive shear strengths of various bonding attachment bases. Am J Orthod 1980; 77: 669–78.

16.

Mackay

The effect of adhesive type and thickness on bond strength of orthodontic brackets. Br J Orthod 1992; 19: 35–39.

17.

Klocke

, Kahl-Nieke

Influence of force location in orthodontic shear bond strength testing. Dent Mater 2005; 21: 391–96.

18.

Soderquist

, Drummond

, Evans

. Bond strength evaluation of ceramic and stainless steel bracket bases subjected to cyclic tensile loading. Am J Orthod Dentofac Orthop 2006; 129: 175e7–e12.

19.

Reynolds

. A review of direct orthodontic bonding. Br J Orthod 1975; 2: 171–78.

20.

Montasser

. Effect of applying a sustained force during bonding orthodontic brackets on the adhesive layer and on shear bond strength. Eur J Orthod 2011; 33: 402–06.

21.

Retief

. The mechanical bond. Int Dent J 1978; 28: 18–27.

22.

Daskalogiannakis

Glossary of Orthodontic Terms. Chicago, IL: Quintessence Publishing Company, Inc., 2000, 112.

23.

Kruzic

, Nalla

, Kinney

, Ritchie

. Crack blunting, crack bridging and resistance-curve fracture mechanics in dentin: effect of hydration. Biomaterials 2003; 24: 5209–21.

24.

Loughran

, Versluis

, Douglas

. Evaluation of sub-critical fatigue crack propagation in a restorative composite. Dent Mater 2005; 21: 252–61.

25.

Pickett

, Sadowsky

, Jacobson

, Lacefield

Orthodontic in vivo bond strength: comparison with in vitro results. Angle Orthod 2001; 71: 141–48.

26.

Hajrassie

, Khier

. In-vivo and in-vitro comparison of bond strengths of orthodontic brackets bonded to enamel and debonded at various times. Am J Orthod Dentofac Orthop 2007; 131: 384–90.