Effect of water, saliva and blood contamination on bonding of metal brackets with a 4-META/MMA/TBB resin to etched enamel.
OBJECTIVE
To investigate the influence of contamination by water, human saliva, and blood on the bonding of metal brackets with a 4-META/MMA/TBB resin to etched enamel.


METHODS
For compressive shear bond strength measurements, the surfaces of bovine enamel were prepared either by etching with 37% phosphoric acid solution for 10, 30, or 60 s and then dried with oil-free compressed air for 10 s, or by contaminating with water, human saliva, and blood. Brackets were applied with Super Bond under loads of 200, 400, or 600 g. The bonded samples were immersed in water for 1 d or thermo-cycled for 500 cycles, and the mean shear bond strengths were compared using two-way ANOVA and Scheffé's multiple comparisons test at P = 0.05.


RESULTS
The bond strengths to enamel etched for 60 s were independent of the variable load, regardless of the type of contamination. A short etching duration provided higher bond strengths than extended etching of samples contaminated with saliva and blood. The bond strengths to enamel etched for 10 s after thermal stress and immersion in water were from 11.4 to 30.4 MPa. The samples contaminated by saliva showed the lowest bond strength, and thermal stress did not reduce the bond strengths.
Itoh
T
T
Department of Orthodontics, Fukuoka Dental College, Japan. itoh@college.fdcnet.ac.jp
Fukushima
T
T
Inoue
Y
Y
Arita
S
S
Miyazaki
K
K
D000180:Acrylic Resins; D000704:Analysis of Variance; D000818:Animals; D001769:Blood; D001896:Boron Compounds; D002417:Cattle; D019245:Compressive Strength; D001840:Dental Bonding; D003743:Dental Enamel / Q000648:ultrastructure; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates; D008768:Methylmethacrylates; D008855:Microscopy, Electron, Scanning; D016910:Orthodontic Brackets; D019279:Resin Cements; D012463:Saliva; D018709:Statistics, Nonparametric; D014867:Water
D000180:Acrylic Resins; D001896:Boron Compounds; D008689:Methacrylates; D008768:Methylmethacrylates; D019279:Resin Cements; D014867:Water; C031172:4-META resin; C049495:Super-bond