Influence of air-particle deposition protocols on the surface topography and adhesion of resin cement to zirconia

Abstract

OBJECTIVES This study evaluated the influence of air-particle abrasion protocols on the surface roughness (SR) of zirconia and the shear bond strength (SBS) of dual-polymerized resin cement to this ceramic. MATERIALS AND METHODS Sintered zirconia blocks (n = 115) (Lava, 3M ESPE) were embedded in acrylic resin and polished. The specimens were divided according to the 'particle type' (Al: 110 µm Al2O3; Si: 110 µm SiO2) and 'pressure' factors (2.5 or 3.5 bar) (n = 3 per group): (a) Control (no air-abrasion); (b) Al2.5; (c) Si2.5; (d) Al3.5; (e) Si3.5. SR (Ra) was measured 3-times from each specimen after 20 s of air-abrasion (distance: 10 mm) using a digital optical profilometer. Surface topography was evaluated under SEM analyses. For the SBS test, 'particle type', 'pressure' and 'thermocycling' (TC) factors were considered (n = 10; n = 10 per group): Control (no air-abrasion); Al2.5; Si2.5; Al3.5; Si3.5; ControlTC; Al2.5TC; Si2.5TC; Al3.5TC; Si3.5TC. After silane application, resin cement (Panavia F2.0) was bonded and polymerized. Specimens were thermocycled (6.000 cycles, 5-55°C) and subjected to SBS (1 mm/min). Data were analyzed using ANOVA, Tukey's and Dunnett tests (5%). RESULTS 'Particle' (p = 0.0001) and 'pressure' (p = 0.0001) factors significantly affected the SR. All protocols significantly increased the SR (Al2.5: 0.45 ± 0.02; Si2.5: 0.39 ± 0.01; Al3.5: 0.80 ± 0.01; Si3.5: 0.64 ± 0.01 µm) compared to the control group (0.16 ± 0.01 µm). For SBS, only 'particle' factor significantly affected the results (p = 0.015). The SiO2 groups presented significantly higher SBS results than Al2O3 (Al2.5: 4.78 ± 1.86; Si2.5: 7.17 ± 2.62; Al3.5: 4.97 ± 3.74; Si3.5: 9.14 ± 4.09 MPa) and the control group (3.67 ± 3.0 MPa). All TC specimens presented spontaneous debondings. SEM analysis showed that Al2O3 created damage in zirconia in the form of grooves, different from those observed with SiO2 groups. CONCLUSIONS Air-abrasion with 110 µm Al2O3 resulted in higher roughness, but air-abrasion protocols with SiO2 promoted better adhesion. AbstractObjectives. This study evaluated the influence of air-particle abrasion protocols on the surface roughness (SR) of zirconia ceramic and the adhesion of dual-polymerized resin cement to this ceramic. Material and methods. Sintered zirconia blocks (N=115) (Lava, 3M ESPE) were embedded in acrylic resin and polished. The specimens were randomly divided into the following experimental groups considering the particle type (Al: 110 µm

Effect of Air-Abrasion Regimens and Fine Diamond Bur Grinding on Flexural Strength, Weibull Modulus and Phase Transformation of Zirconium Dioxide

“…It can be explained by the fact that force during particle deposition could erode the peaks and the depths but at the same time they are partially embedded on the surface diminishing eventually the surface roughness in these groups. Although alumina promotes rougher surface than silica coating, the bond strength between ceramic and resin cement is higher for silica coating than alumina abrasion, because of its chemical interaction to resin cement after silanization (26).…”

Characterization of Conventional and High-Translucency Y-TZP Dental Ceramics Submitted to Air Abrasion

“…Thus, the interaction between the materials (ceramic and resinbased cement) could be more effective. Second, the increased surface area and deep valleys produced by air-abrasion on ceramic surfaces will create more sites of retention available to the in situ polymerization of the resin-based cement (17,24).…”

Adhesion to Zirconium Dioxide Used for Dental Reconstructions: Surface Conditioning Concepts, Challenges, and Future Prospects

“…Thus, delicate application of air-abrasion protocols, using smaller particle size of 50 µm or less, as short as possible (approximately 20 s/cm 2 ) between 0.5 to 2.5 bar and with controlled nozzle distance of approximately 10 mm are among currently accepted conditioning parameters [9,35,37]. The increase in pressure during air-abrasion procedures can produce even deeper surface morphology, hindering the wettability and flow of resin luting cement into the irregularities [39,42].…”

“…In fact, the impact of particle deposition methods on zirconia is dependent on parameters such as particle morphology, pressure and duration [37] effecting residual compressive stress layer that stimulates phase transformation (t→m) and creates transformed zone depth (TZD) [9,40]. TZD typically ranges from 0.59 to 1.6 µm and interestingly with the good combination of deposition parameters this zone may even increases mechanical strength of zirconia [38,[40][41][42]. ISO standard 13356 suggests 25% as the maximum acceptable amount of monoclinic phase [8].…”

“…To date, controversial opinions are present regarding the harmful effects of particle deposition methods on zirconia [38][39][40][41][42], in that momentum of particles on zirconia yield to local lattice distortions or create new phase by ferroelastic domain switching. In fact, the impact of particle deposition methods on zirconia is dependent on parameters such as particle morphology, pressure and duration [37] effecting residual compressive stress layer that stimulates phase transformation (t→m) and creates transformed zone depth (TZD) [9,40].…”