Ferhan Egilmez1, Gulfem Ergun1, Isil Cekic-Nagas1, Pekka K Vallittu2, Mutlu Ozcan3, Lippo V J Lassila2. 1. Department of Prosthodontics, Gazi University Faculty of Dentistry, Ankara, Turkey. 2. Department of Biomaterials Science and Turku Clinical Biomaterials Centre, Institute of Dentistry, University of Turku, Turku, Finland. 3. Dental Materials Unit, Center for Dental and Oral Medicine-Clinic for Fixed and Removable Prosthodontics and Dental Materials Science, University of Zurich, Zurich, Switzerland.
Abstract
PURPOSE: This study aimed to evaluate the micro push-out (μ-PO) bond strength between zirconia and resin cement after addition of zirconia particles to increase the surface roughness. MATERIALS AND METHODS: Y-TZP zirconia specimens in three experimental groups were subjected to Y-TZP particle deposition via dipping into the milling residue suspension at different times prior to the sintering process. The dipping procedure was repeated twice for each specimen in group B, six times in group C, and ten times in group D. The specimens subjected to airborne-particle abrasion (110 μm Al2 O3, Rocatec Pre) acted as the control group (group A). All of the specimens were then bonded using adhesive resin cement (RelyX Ultimate). A μ-PO test was used to determine the bond strength values. One-way ANOVA at a 5% confidence level was performed for data analysis. Optical microscopy and scanning electron microscopy (SEM) were used to evaluate the failure modes and surface structure. RESULTS: Y-TZP particle deposition did not have a significant effect on the bond strength of the resin cement to zirconia specimens when compared to the control (p = 0.141). Higher bond strength values were observed in groups C and D than in control. The surface layer presented blister-like porosities with openings of various diameters ranging between 2 and 4 μm. CONCLUSION: Y-TZP particle deposition after dipping six and ten times did not improve the mean bond strength statistically but presented surface topography that may be favorable for increased micromechanical retention for adhesive resin cement. CLINICAL SIGNIFICANCE: Y-TZP particle deposition may create a more retentive surface than airborne-particle abrasion for adhesive bonding between zirconia surface and resin cement.
PURPOSE: This study aimed to evaluate the micro push-out (μ-PO) bond strength between zirconia and resin cement after addition of zirconia particles to increase the surface roughness. MATERIALS AND METHODS:Y-TZP zirconia specimens in three experimental groups were subjected to Y-TZP particle deposition via dipping into the milling residue suspension at different times prior to the sintering process. The dipping procedure was repeated twice for each specimen in group B, six times in group C, and ten times in group D. The specimens subjected to airborne-particle abrasion (110 μm Al2 O3, Rocatec Pre) acted as the control group (group A). All of the specimens were then bonded using adhesive resin cement (RelyX Ultimate). A μ-PO test was used to determine the bond strength values. One-way ANOVA at a 5% confidence level was performed for data analysis. Optical microscopy and scanning electron microscopy (SEM) were used to evaluate the failure modes and surface structure. RESULTS:Y-TZP particle deposition did not have a significant effect on the bond strength of the resin cement to zirconia specimens when compared to the control (p = 0.141). Higher bond strength values were observed in groups C and D than in control. The surface layer presented blister-like porosities with openings of various diameters ranging between 2 and 4 μm. CONCLUSION:Y-TZP particle deposition after dipping six and ten times did not improve the mean bond strength statistically but presented surface topography that may be favorable for increased micromechanical retention for adhesive resin cement. CLINICAL SIGNIFICANCE: Y-TZP particle deposition may create a more retentive surface than airborne-particle abrasion for adhesive bonding between zirconia surface and resin cement.