Bond strength of a resin cement to high-alumina and zirconia-reinforced ceramics: the effect of surface conditioning.
OBJECTIVE
The aim of this study was to evaluate the effect of two surface conditioning methods on the microtensile bond strength of a resin cement to three high-strength core ceramics: high alumina-based (In-Ceram Alumina, Procera AllCeram) and zirconia-reinforced alumina-based (In-Ceram Zirconia) ceramics.


METHODS
Ten blocks (5 x 6 x 8 mm) of In-Ceram Alumina (AL), In-Ceram Zirconia (ZR), and Procera (PR) ceramics were fabricated according to each manufacturer's instructions and duplicated in composite. The specimens were assigned to one of the two following treatment conditions: (1) airborne particle abrasion with 110-microm Al2O3 particles + silanization, (2) silica coating with 30 microm SiOx particles (CoJet, 3M ESPE) + silanization. Each ceramic block was duplicated in composite resin (W3D-Master, Wilcos, Petrópolis, RJ, Brazil) using a mold made out of silicon impression material. Composite resin layers were incrementally condensed into the mold to fill up the mold and each layer was light polymerized for 40 s. The composite blocks were bonded to the surface-conditioned ceramic blocks using a resin cement system (Panavia F, Kuraray, Okayama, Japan). One composite resin block was fabricated for each ceramic block. The ceramic-composite was stored at 37 degrees C in distilled water for 7 days prior to bond tests. The blocks were cut under water cooling to produce bar specimens (n = 30) with a bonding area of approximately 0.6 mm2. The bond strength tests were performed in a universal testing machine (crosshead speed: 1 mm/min). Bond strength values were statistically analyzed using two-way ANOVA and Tukey's test (< or = 0.05).


RESULTS
Silica coating with silanization increased the bond strength significantly for all three high-strength ceramics (18.5 to 31.2 MPa) compared to that of airborne particle abrasion with 110-microm Al2O3 (12.7-17.3 MPa) (ANOVA, p < 0.05). PR exhibited the lowest bond strengths after both Al2O3 and silica coating (12.7 and 18.5 MPa, respectively).


CONCLUSIONS
Conditioning the high-strength ceramic surfaces with silica coating and silanization provided higher bond strengths of the resin cement than with airborne particle abrasion with 110-microm Al2O3 and silanization.
Valandro
Luiz Felipe
LF
Department of Restorative Dentistry, Federal University of Santa Maria, Brazil.
Ozcan
Mutlu
M
Bottino
Marco Cícero
MC
Bottino
Marco Antonio
MA
Scotti
Roberto
R
Bona
Alvaro Della
AD
D020906:Air Abrasion, Dental; D000537:Aluminum Oxide / Q000737:chemistry*; D002516:Ceramics / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003776:Dental Porcelain / Q000737:chemistry*; D003799:Dental Stress Analysis / Q000295:instrumentation; D006801:Humans; D008422:Materials Testing; D019279:Resin Cements / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength; D014867:Water / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry*
C105314:AllCeram; D003188:Composite Resins; C483026:In-Ceram Alumina; C485633:In-Ceram Zirconia; C438843:Panavia-Fluoro; D019279:Resin Cements; D012821:Silanes; D014867:Water; D003776:Dental Porcelain; D012822:Silicon Dioxide; D015040:Zirconium; D000537:Aluminum Oxide; C028541:zirconium oxide