Effect of Oxidation and SiO2 Coating on the Bonding Strength of Ti-Porcelain

Abstract

Investigations on the effect of oxidation on titanium-ceramic adhesion were performed. Cast pure titanium was subjected to surface modification by preoxidation and introduction of an intermediate layer of SiO 2 by sol-gel process. Specimens were characterized by TG-DSC, XRD, and SEM/EDS. The adhesion between the titanium and porcelain was evaluated by three-point flexure bond test. Failure of the titanium-porcelain with preoxidation treatment predominantly occurred at the titanium-oxide interface. Preoxidation treatment did not affect the fracture mode of the titanium-ceramic system and did not increase the bonding strength of Ti-porcelain. The SEM results revealed the existence of microcracks on the SiO 2 coating surface oxidized at 800°C in an air furnace. During the porcelain fusion, minute amounts of oxygen were able to penetrate the cracks and caused localized oxidation of the Ti-substrate. Failure of the titanium-porcelain with SiO 2 coating predominantly occurred at the SiO 2 layer. The SiO 2 coating served as an effective oxygen diffusion barrier and improved the mechanical and chemical bonding between porcelain and titanium.

Improvement in Dental Porcelain Bonding to Milled, Noncast Titanium Surfaces by Gold Sputter Coating

“…Our EDS analysis results indicated that no contamination by the Al 2 O 3 particles was present on the sandblasted Ti surface (SB group), which also demonstrated sufficient bonding with the porcelain (bond strength 28.76 MPa). This bond strength value was similar to previously reported values …”

Titanium - ceramic restoration: How to improve the binding between titanium and ceramic

“…The effect of cooling rate is due to the change of heat stress of Ti-ceramic interface. 30 As a conclusion, the bond of ceramic over titanium is a sensitive technique influenced by the effects provoked mainly by the layer of surface oxide. Titanium and titanium alloys, based on their physical and chemical properties suitable for titanium-ceramic restorations, but careful selection of processing methods, ceramic materials, laboratory skill and strict protocol for ceramic bonding to titanium are necessary to improve the bonding between titanium and ceramic.…”

“…26 The use of Au (gold), 6,29 Si 3 N 4 , chrome, SiO 2 and TiO 2 as intermediate layers has been investigated. 30 Several study showed that the titanium ceramic adhesion could be improved by coating cast titanium surface with Au. 29 This can be explained by the formation a Ti-Au intermetallic compound and surpressed the formation of a Ti-deficient intermediate layer, resulting in improved adherence between ceramic and titanium.…”

“…2 Silica (SiO 2 ) coating was an effective intermediate layer to improve titanium-ceramic adhesion, 30 it could be suggested that the oxidation of the Ti-ceramic sysem; during the ceramic fusion, minute amounts of oxygen were able to penetrate the cracks and caused localized oxidation of the Ti-substrate. The SiO 2 coating prevented the diffusion of oxygen to the titanium surface and improved the mechanical and chemical bonding between titanium and ceramic and another study reported that when ceramic was fired in vacuum in the presence of the gold layer, the titanium-ceramic bonding was weakened in as-cast titanium and was not affected in machined titanium.…”

Bonding of dental porcelain to non-cast titanium with different surface treatments

“…The bond strength primarily depends on the mechanical and chemical properties of the interface between the metal and porcelain 9,10) . Although extensive studies have employed different surface treatments of Ti prior to porcelain sintering [11][12][13][14][15][16][17][18][19] , a simple and practical technique to improve Ti-porcelain bond strength has not been well determined, and the underlying mechanism for the bonding of Ti and porcelain is not well understood.Chemical solution treatment is a method that can be used to treat and clean metallic surfaces for clinical applications 20) . In industrial fields, an alkaline or acid solution has been successfully employed to clear superficial pollutants from Ti and Ti alloys 21) .…”