Novel silane encapsulation system for tribochemical resin bonding to a Co-Cr alloy

Abstract

A B S T R A C TObjectives: Encapsulated silane has been introduced in powders for tribochemical coating (SilJet Plus, SP), eliminating the need for a separate silane primer. The aim of the study was to comparatively evaluate the effect of SP on the surface properties and bond strength of a Co-Cr alloy with a resin composite. Methods: Co-Cr cast alloy disks were subjected to tribochemical treatments with CoJet (CJ), SilJet (SJ) and SP. Polished specimens were used as control (CR). The alloy surfaces were studied by optical profilometry (OIP; parameters Sa,Sz,Sdr,Sci), reflection FTIR microscopy (RFTIRM; CR,CJ,SJ silanized with S-Bond), scanning electron microscopy/energy dispersive X-ray microanalysis (SEM/EDX; Al + Si coverage), contact angle with water (CW) and shear bond strength with a flowable resin composite (SBS). Statistical analysis for OIP, Al + Si coverage, CW and SBS was performed by one-way ANOVA and Holm-Sidak multiple comparison tests and by Chi-square for the failure mode (a = 0.05). Results: CR demonstrated the lowest Sa,Sz,Sdr values from all sandblasted surfaces, excluding Sci of SJ. Among tribochemical treatments, no differences were found in Sa,Sz. CJ showed lower Sdr and SJ higher Sci. The peaks of SiÀ ÀOÀ À were very weak on CR, but detectable on CJ, SJ and SP, with no evidence of SiÀ ÀOÀ ÀCH 3 groups. The ranking of the statistical significant differences in CW measurements was SP > SJ + silane > CJ + silane > CR + silane. Well-defined Al and diffuse Si distributions were found on the alloy surface following tribochemical treatments. The maximum Al + Si coverage ranged between 50 and 54% (5000Â) and the random coverage between 7 and 11% (1000Â, p > 0.05 for both). Tribochemical treatments showed higher SBS from CR (p < 0.05), but with no statistically significant differences among them. CR demonstrated exclusively adhesive failures, whereas in tribochemically coated groups adhesive failures ranged from 10 to 20%. Clinical significance: Tribochemical treatments with encapsulated silane may be considered an efficient single-step alternative to conventional two-step systems for bonding to Co-Cr alloys, offering a significant reduction in chairside time.

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

“…The SBS values of PF and PC were significantly higher than ML, because of the establishment of interfacial bonding conditions on the rough substrate of zirconia and alumina. Alumina fragments implanted in zirconia surface have been identified after alumina grit-blasting or tribo-chemical coating procedures [ 12 , 13 ], where phosphate monomers can bond chemically [ 40 ]. The statistically insignificant differences in SBS between PC and PF on AL before and after TC, imply that the carboxylic monomers in PC do not substantially contribute to the SBS, especially when these cements demonstrated significant differences in the controls (CL).…”

“…For chemical bonding, adhesive monomers, mainly phosphate functionalized methacrylates, have been introduced in the resin composite luting agents and/or in their primers [ 3 , 8 , 9 ]. These monomers have been shown to react with zirconia [ 10 , 11 , 12 , 13 ] via three mechanisms, producing different Zr-P compounds [ 14 ]. The monodentate Zr-P salt has been considered as the primary bonding mechanism between a phosphate monomer (10-methacryloyloxydecyl dihydrogen phosphate/10-MDP) and zirconia [ 15 ], although the contribution of the bridging bidentate (two Zr bonded to one P) and phosphates bridged to Zr (two P bonded to one Zr) compounds cannot be excluded [ 10 ].…”