Shear bond strength of brackets bonded with two light-curing orthodontic adhesives.
OBJECTIVE
To compare the shear bond strength of stainless steel brackets bonded with two orthodontic adhesive systems, Transbond XT (3M Unitek) and Orthobond (Morelli Dental Products).


METHODS
Forty bovine teeth were randomly divided in two groups of 20 each: group 1 (control): Transbond XT primer + Transbond XT Adhesive paste (3M Unitek); group 2: Orthoprimer (Morelli Dental Products) + Orthobond. In each group all teeth were etched with 37% phosphoric acid, and all products were used according to manufacturers instructions. After 30 min, a universal testing machine was used to apply an occlusal shear force directly to the enamel/bracket interface at a speed of 0.5 mm/min. The groups were compared using Student's t-test.


RESULTS
Mean results and standard deviations for the groups were: group 1= 11.22 Mpa (1.68), group 2= 4.88 Mpa (1.18). A significant difference was observed in the bond strengths of the two groups evaluated (p < 0.0001).


CONCLUSIONS
Under the conditions of this study, Orthobond system presented lower shear bond strength when compared to Transbond XT.
Vilar
Rowan V
RV
School of Dentistry, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
Souza
Nathaly F
NF
Cal-Neto
Julio P
JP
Galvão
Myrela
M
Sampaio-Filho
Hélio
H
Mendes
Alvaro de Moraes
Ade M
D000134:Acid Etching, Dental; D000818:Animals; D002417:Cattle; D003188:Composite Resins / Q000737:chemistry; D055117:Curing Lights, Dental; D001840:Dental Bonding; D003743:Dental Enamel / Q000648:ultrastructure; D003799:Dental Stress Analysis / Q000295:instrumentation; D008422:Materials Testing; D016910:Orthodontic Brackets; D010756:Phosphoric Acids / Q000737:chemistry; D011897:Random Allocation; D019279:Resin Cements / Q000737:chemistry*; D033081:Shear Strength; D013193:Stainless Steel / Q000737:chemistry; D013314:Stress, Mechanical; D013997:Time Factors
D003188:Composite Resins; D010756:Phosphoric Acids; D019279:Resin Cements; C429625:Transbond Plus Self-Etching Primer; C477790:Transbond XT; C516047:Transbond XT Light Cure Adhesive Primer; D013193:Stainless Steel; C030242:phosphoric acid