Are nano-composites and nano-ionomers suitable for orthodontic bracket bonding?

The aim of this study was to test nano-composite (Filtek Supreme Plus Universal) and a newly introduced nano-ionomer (Ketac N100 Light Curing Nano-Ionomer) restorative to determine their shear bond strength (SBS) and failure site locations in comparison with a conventional light-cure orthodontic bonding adhesive (Transbond XT). Sixty freshly extracted human maxillary premolar teeth were arbitrarily divided into three equal groups. The brackets were bonded to the teeth in each group with different composites, according to the manufacturers' instructions. The SBS values of the brackets were recorded in Megapascals (MPa) using a universal testing machine. Adhesive remnant index scores were determined after failure of the brackets. The data were analysed using analysis of variance, Tukey honestly significant difference, and chi-square tests. The results demonstrated that group 1 (Transbond XT, mean: 12.60 +/- 4.48 MPa) had a higher SBS than that of group 2 (nano-composite, mean: 8.33 +/- 5.16 MPa; P < 0.05) and group 3 (nano-ionomer, mean: 6.14 +/- 2.12 MPa; P < 0.001). No significant differences in debond locations were found among the three groups. Nano-composites and nano-ionomers may be suitable for bonding since they fulfil the previously suggested SBS ranges for clinical acceptability, but they are inferior to a conventional orthodontic composite.

[1]  I. Reynolds.  A Review of Direct Orthodontic Bonding , 1975 .

[2]  A. Gwinnett,et al.  Incidence of white spot formation after bonding and banding. , 1982, American journal of orthodontics.

[3]  J Artun,et al.  Clinical trials with crystal growth conditioning as an alternative to acid-etch enamel pretreatment. , 1984, American journal of orthodontics.

[4]  R. N. Moore,et al.  Bonding orthodontic acrylic resin to enamel. , 1988, American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics.

[5]  B. Øgaard.  Prevalence of white spot lesions in 19-near-olds: A study on untreated and orthodontically treated persons 5 years after treatment , 1989 .

[6]  B. Ogaard,et al.  Prevalence of white spot lesions in 19-year-olds: a study on untreated and orthodontically treated persons 5 years after treatment. , 1989, American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics.

[7]  D. Ferguson,et al.  Shear, torsional, and tensile bond strengths of ceramic brackets using three adhesive filler concentrations. , 1991, American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics.

[8]  C. Davidson,et al.  Influence of filler parameters on the mechanical coherence of dental restorative resin composites. , 1996, Biomaterials.

[9]  L. Forsten.  Fluoride release and uptake by glass-ionomers and related materials and its clinical effect. , 1998, Biomaterials.

[10]  Raymond E. Kirk,et al.  Encyclopedia of chemical technology , 1998 .

[11]  N. Moszner,et al.  New developments of polymeric dental composites , 2001 .

[12]  G. Leloup,et al.  Dynamic and static moduli of elasticity of resin-based materials. , 2002, Dental materials : official publication of the Academy of Dental Materials.

[13]  N. Moszner,et al.  Nanotechnology for dental composites , 2004 .

[14]  Raed Ajlouni,et al.  Evaluation of a new nano-filled restorative material for bonding orthodontic brackets. , 2007, World journal of orthodontics.