Influence of surface treatment on the shear bond strength of ceramics fused to cobalt-chromium.
OBJECTIVE
To evaluate the influence of surface treatment on the shear bond strength between a Co-Cr alloy and two ceramics.


METHODS
Forty-eight metal cylinders were made (thickness: 4 mm, height: 3.7 mm) according ISO TR 11405. The 48 metallic cylinders were divided into four groups (n = 12), according to the veneering ceramic (StarLight Ceram and Duceram Kiss) and surface treatments: air-particle abrasion with Al(2)O(3) or tungsten drill (W). Gr1: StarLight + Al(2)O(3); Gr2: StarLight + W; Gr3: Duceram + Al(2)O(3); and Gr4: Duceram + W. The specimens were aged using thermal cycling (3000x, 5 to 55 degrees C, dwell time: 30 seconds, transfer time: 2 seconds). The shear test was performed with a universal testing machine, using a load cell of 100 kg (speed: 0.5 mm/min) and a specific device. The bond strength data were analyzed using ANOVA and Tukey's test (5%), and the failure modes were analyzed using an optical microscope (30x).


RESULTS
The means and standard deviations of the shear bond strengths were (MPa): G1 (57.97 +/- 11.34); G2 (40.62 +/- 12.96); G3 (47.09 +/- 13.19); and G4 (36.80 +/- 8.86). Ceramic (p= 0.03252) and surface treatment (p= 0.0002) significantly affected the mean bond strength values.


CONCLUSIONS
Air-particle abrasion with Al(2)O(3) improved the shear bond strength between metal and ceramics used.
Lombardo
Geraldo H L
GH
São Jose dos Campos Dental School, São Paulo State University (UNESP), São Paulo, Brazil.
Nishioka
Renato S
RS
Souza
Rodrigo O A
RO
Michida
Silvia M A
SM
Kojima
Alberto N
AN
Mesquita
Alfredo M M
AM
Buso
Leonardo
L
D020906:Air Abrasion, Dental; D000704:Analysis of Variance; D002858:Chromium Alloys; D003035:Cobalt; D001840:Dental Bonding; D003776:Dental Porcelain; D003799:Dental Stress Analysis; D008422:Materials Testing; D016876:Metal Ceramic Alloys; D008855:Microscopy, Electron, Scanning; D033081:Shear Strength; D018709:Statistics, Nonparametric; D013499:Surface Properties
D002858:Chromium Alloys; D016876:Metal Ceramic Alloys; D003776:Dental Porcelain; D003035:Cobalt