Evaluation of bond strength of various margin ceramics to a zirconia ceramic.
OBJECTIVE
This study evaluated the bond strengths of four different margin ceramics based on fluoroapatite and feldspath to a zirconia ceramic.


METHODS
Zirconia cores (Zirconzahn) (N=28, n=7/margin ceramic group) were fabricated according to the manufacturers' instructions (diameter: 4mm; thickness: 2mm) and ultrasonically cleaned. Four different margin ceramics (thickness: 5mm) (Cerabien Zr, Noritake; Ceramco PFZ, Ceramco; e.max, Ivoclar Vivadent and Triceram, Dentaurum) were vibrated and condensed in a stainless steel mould and fired onto their zirconia cores. After trying the specimens in the mould for minor adjustments, they were again ultrasonically cleaned and embedded in PMMA. The specimens were stored in distilled water at 37 degrees C for 1 week and shear bond strength (MPa+/-S.D.) tests were performed in a universal testing machine (crosshead speed: 0.5mm/min). Failure modes were recorded under SEM.


RESULTS
Significant effect of margin ceramic types were found on the bond strength values (P<0.05). The mean bond strength values of Ceramco margin ceramic to zirconia was significantly lower (25.4+/-4.5 MPa) (P<0.05) than those of Cerabien (31.6+/-6.4 MPa), e.max (35.9+/-8.4 MPa), and Triceram margin ceramic (38.8+/-7.1 MPa) systems.


CONCLUSIONS
Margin ceramics, compatible with zirconia framework material tested in the present study, exhibited high bond strength values. Variations in thermal expansion coefficients might influence their bond strength values.
Cömlekoğlu
M Erhan
ME
Ege University, School of Dentistry, Department of Prosthodontics, Izmir, Turkey. erhancomlek@yahoo.com
Dündar
Mine
M
Ozcan
Mutlu
M
Güngör
M Ali
MA
Gökçe
Bülent
B
Artunç
Celal
C
D002518:Ceramides / Q000737:chemistry; D001840:Dental Bonding; D018772:Dental Marginal Adaptation; D003776:Dental Porcelain / Q000737:chemistry*; D003799:Dental Stress Analysis; D003801:Dental Veneers; D008422:Materials Testing; D016876:Metal Ceramic Alloys / Q000737:chemistry*; D011176:Post and Core Technique / Q000295:instrumentation; D011474:Prosthesis Design; D033081:Shear Strength; D015040:Zirconium / Q000737:chemistry*
D002518:Ceramides; D016876:Metal Ceramic Alloys; C436063:TriCeram; D003776:Dental Porcelain; C058233:Ceramco; D015040:Zirconium; C028541:zirconium oxide