Effect of Water Storage on Hardness and Interfacial Strength of Resin Composite Luting Agents Bonded to Surface-Treated Monolithic Zirconia

• Published in: Dentistry journal Vol. 9; no. 7; p. 78
• Main Authors: Tzanakakis, Emmanouil-George, Dimitriadi, Maria, Tzoutzas, Ioannis, Koidis, Petros, Zinelis, Spiros, Eliades, George
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 04.07.2021; MDPI
• Subjects: Adhesive strength; Adhesives; Aluminum oxide; Bond strength; Bonding agents; Bonding strength; Cements; Chemical bonds; Composite materials; Coupling agents; Dental cement; Diamond pyramid hardness; Hardness; Interfacial strength; Intervals; Laboratories; Mechanical properties; Monomers; Parameters; Phosphates; Ranking; resin composite luting agents; Resins; Roughness; sandblasting; shear bond strength; Shear strength; Shear tests; Silanes; Silica; Silicon dioxide; Subgroups; Surface treatment; Topography; Water hardness; Water storage; Zirconia; zirconia ceramic; Zirconium dioxide; United States > US; Germany
• ISSN: 2304-6767; 2304-6767
• DOI: 10.3390/dj9070078

Background: Durable bonding between resin composite luting agents (CLA) and zirconia is still a matter of controversy. The purpose of this study was to evaluate the effect of water storage on hardness and interfacial strength of three CLA, a non-adhesive (Multilink Automix/ML), an adhesive (Panavia F 2.0/PF) and a self-adhesive (PermaCem 2.0/PC), bonded to polished (CL) and grit-blasted (AL: 50 μm alumina, SJ: Sil-Jet + Monobond Plus silane) monolithic zirconia surfaces. Methods: CLA specimens (n = 5/cement, condition) were prepared, stored under dry conditions or immersed in water, and Vickers hardness (VH) measurements were obtained at 1 h, 24 h, 1 week and 3 weeks intervals. Optical profilometry was used to determine the roughness parameters (Sa, Sz, Sdr, Sci) of zirconia surfaces (n = 5/treatment). A shear strength test (SBS, n = 10 × 2/cement) was performed to assess the strength and fractography of the cements bonded to zirconia after isothermal water storage and thermal-cycling (TC). Results: PF demonstrated significantly lower VHN after water storage at all time intervals, PC at 1 w, 3 w and ML at 3 w. SJ and AL showed significantly higher values from CL in all roughness parameters. Weibull analysis revealed the following significance in σο ranking within the same material: AL, SJ, ALTC > SJTC, CL > CLTC (PF); SJ, SJTC, AL, ALTC > CL, CLTC (PC) and SJ, SJTC > AL > ALTC > CL, CLTC (ML). Within the same surface treatment subgroups, the significance in σo ranking was PC, ML > PF (before/after TC) for SJ; PC > PF > ML (before TC), PC, PF > ML (after TC) for AL, and PC > PF > ML (before/after TC) for CL. For the m ranking, the only significant difference within each material group was found in PC (AL > ALTC) and for the same surface treatment in AL (PC > ML). Conclusion: There are significant differences in the water plasticization susceptibility of the CLA tested; the materials with adhesive monomers were the most affected. Tribo-chemical silica coating combined with a silane coupling agent was the most efficient bonding treatment for the non-adhesive and the self-adhesive materials. The adhesive CLA performed better on alumina-blasted than on tribo-chemically coated surfaces.