Evaluation of a new nano-filled restorative material for bonding orthodontic brackets.
OBJECTIVE
To compare the shear bond strength of a nano-hybrid restorative material, Grandio (Voco, Cuxhaven, Germany), to that of a traditional adhesive material (Transbond XT; 3M Unitek, Monrovia, CA, USA) when bonding orthodontic brackets.


METHODS
Forty teeth were randomly divided into 2 groups: 20 teeth were bonded with the Transbond adhesive system and the other 20 teeth with the Grandio restorative system, following manufacturer's instructions. Student t test was used to compare the shear bond strength of the 2 systems. Significance was predetermined at P 5 .05.


RESULTS
The t test comparisons (t = 0.55) of the shear bond strength between the 2 adhesives indicated the absence of a significant (P = .585) difference. The mean shear bond strength for Grandio was 4.1 +/- 2.6 MPa and that for Transbond XT was 4.6 +/- 3.2 MPa. During debonding, 3 of 20 brackets (15%) bonded with Grandio failed without registering any force on the Zwick recording. None of the brackets bonded with Transbond XT had a similar failure mode.


CONCLUSIONS
The newly introduced nano-filled composite materials can potentially be used to bond orthodontic brackets to teeth if its consistency can be more flowable to readily adhere to the bracket base.
Bishara
Samir E
SE
Department of Orthodontics, College of Dentistry, University of Iowa, Iowa City, IA 52242, USA. sbishara@msn.com
Ajlouni
Raed
R
Soliman
Manal M
MM
Oonsombat
Charuphan
C
Laffoon
John F
JF
Warren
John
J
D000134:Acid Etching, Dental; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003743:Dental Enamel / Q000648:ultrastructure; D003764:Dental Materials / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D053758:Nanoparticles / Q000737:chemistry*; D016910:Orthodontic Brackets; D019279:Resin Cements / Q000737:chemistry*; D033081:Shear Strength; D013314:Stress, Mechanical; D013499:Surface Properties
D003188:Composite Resins; D003764:Dental Materials; C509998:Grandio; D019279:Resin Cements; C477790:Transbond XT