The influence of dynamic fatigue loading on the separate components of the bracket-cement-enamel system.
OBJECTIVE
To evaluate the influence of cyclic loading and type of adhesive on the shear bond strength of the bracket-cement-enamel bond.


METHODS
The materials studied were: Transbond XT (a Bis-GMA resin composite cement), Fuji Ortho LC (a resin-modified glass-ionomer cement), and Fuji IX Fast (a conventional glass-ionomer cement). The shear bond strength (SBS) and the shear bond fatigue limits (SBFL) were determined after 72-hour storage in 37 degrees C water for the cement itself, the button-cement interface, the cement-enamel interface, and the bracket-cement-enamel system. The SBFL was determined with the aid of the "staircase method" at 10,000 cycles. The results were analyzed using ANOVA and Tukey HSD post hoc test (P < 0.05).


RESULTS
ANOVA showed significant differences between the SBS of the materials. Fatigue was observed in all substrate combinations, with the exception for the Fuji IX Fast cement-enamel and the Fuji Ortho LC bracket-cement-enamel combinations.
Algera
Tjalling J
TJ
Department of Orthodontics, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam, The Netherlands.
Kleverlaan
Cornelis J
CJ
Prahl-Andersen
Birte
B
Feilzer
Albert J
AJ
D000180:Acrylic Resins / Q000737:chemistry; D000465:Algorithms; D000538:Aluminum Silicates / Q000737:chemistry; D000818:Animals; D002417:Cattle; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry*; D003743:Dental Enamel / Q000648:ultrastructure*; D005899:Glass Ionomer Cements / Q000737:chemistry; D008422:Materials Testing; D016910:Orthodontic Brackets; D019279:Resin Cements / Q000737:chemistry; D033081:Shear Strength; D013193:Stainless Steel / Q000737:chemistry; D013314:Stress, Mechanical; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry
D000180:Acrylic Resins; D000538:Aluminum Silicates; D003738:Dental Cements; C439808:Fuji IX GP Fast; C095451:Fuji Ortho LC; D005899:Glass Ionomer Cements; D019279:Resin Cements; C477790:Transbond XT; D014867:Water; D013193:Stainless Steel