Air abrasion with 30-50 μm synthetic diamond particles, 60-80 μm cubic boron nitride particles and 110 μm aluminum oxide particles showed higher bond strength values than other methods.

Signum Zirconia Bond is effective for increasing the bond strength of adhesive resin cement to zirconia ceramic.

Background/purpose: Chipping and delaminating of veneering ceramics are critical problems in the fabrication of metal-ceramic restorations. The purpose of this study was to evaluate the effect of different air-abrasion particles on the shear bond strength of a ceramic to nickel-chromium (Ni-Cr) and cobalt-chromium (Co-Cr) alloys. Materials and methods: Forty square specimens (10 mm  10 mm  1.5 mm) were cast for each Ni-Cr and Co-Cr alloys. Specimens were divided into four groups for the air-abrasion procedures: 50-mm aluminum oxid particles (Al 2 O 3 ), 110-mm Al 2 O 3 particles, 30e50-mm synthetic diamond particles, and 60e80-mm cubic boron nitride particles. After the airabrasion procedures, specimens received ceramic veneering. The shear bond strength was determined at a crosshead speed of 1 mm/min. Data were statistically analyzed by a 2-way analysis of variance with post-hoc Tukey's test (a Z 0.05). Effects of the air-abrasion particles on each alloy were examined with a scanning electron microscope. Results: The highest bond strengths were obtained with application of air abrasion with 110-mm Al 2 O 3 particles and the lowest bond strengths were obtained with 50-mm Al 2 O 3 particles (P < 0.05).Conclusions: None of the tested alternative air-abrasion particles provided superior bond strengths compared with 110-mm Al 2 O 3 particles.

PURPOSEAlthough several surface treatments have been recently investigated both under in vitro and in vivo conditions, controversy still exists regarding the selection of the most appropriate zirconia surface pre-treatment. The purpose of this study was to evaluate the effect of alumina (Al) and aluminium nitride (AlN) coating on the shear bond strength of adhesive resin cement to zirconia core.MATERIALS AND METHODSFifty zirconia core discs were divided into 5 groups; air particle abrasion with 50 µm aluminum oxide particles (Al2O3), polishing + Al coating, polishing + AlN coating, air particle abrasion with 50 µm Al2O3 + Al coating and air particle abrasion with 50 µm Al2O3 + AlN coating. Composite resin discs were cemented to each of specimens. Shear bond strength (MPa) was measured using a universal testing machine. The effects of the surface preparations on each specimen were examined with scanning electron microscope (SEM). Data were statistically analyzed by one-way ANOVA (α=.05).RESULTSThe highest bond strengths were obtained by air abrasion with 50 µm Al2O3, the lowest bond strengths were obtained in polishing + Al coating group (P<.05).CONCLUSIONAl and AlN coatings using the reactive magnetron sputtering technique were found to be ineffective to increase the bond strength of adhesive resin cement to zirconia core.

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