Porcelain bonding on Ti: Its dependence on surface roughness, firing time and vacuum level

Abstract

Adherence of porcelain on titanium and possible bonding mechanisms were studied. The main variables were surface roughness, firing time and vacuum level. Adherence was greatly affected by the degree of surface roughness. The bond strength for Al,O,-blasted rough surfaces was superior to those ground by S i c paper or polished. The fracture was partly cohesive for the Al,O,-blasted surfaces as a result of mechanical interlocking. For smoother surfaces fracture occurred adhesively. Increased firing time and reduced vacuum level decreased the bond strength when mechanical interlocking was weak. This was most likely related to poor adherence of the interfacial oxide layer to the titanium substrate.

Effect of sandblasting conditions on alumina retention in representative dental alloys

“…In implant technology, sandblasting with alumina grains is also used for surface roughening in combination with acid-etching to enhance osseointegration 16) , but concerns have been raised regarding the impact of alumina fragments embedded in these surfaces on their eventual osseointegration 17) . Although several previous studies have been performed to estimate the extent of alumina fragment retention 2,8,11,12,14,[16][17][18][19] , their conclusions were not definitive in terms of the effect of alumina grit size and application pressure on the prevalence of embedded fragments. Moreover, disparity in the way the Al content was presented precluded any meaningful comparison among these studies ( Table 1).…”

“…It has been estimated that sandblasting increases the total surface area of a metallic substrate by up to 6.5 times 1) , and increases the metal-ceramic bond strength of dental alloys [2][3][4][5][6] . Despite these benefits of sandblasting with alumina particles, currently available technologies have been inadequate to properly investigate potential adverse effects.…”

SEM/EDS evaluation of porcelain adherence to gold‐coated cast titanium

“…32 It was reported that improved bonding between CP titanium and porcelain was obtained on Al 2 O 3 -particle air-abraded titanium surfaces with increased surface roughness. 15 Mechanical bonding was suggested as the dominant factor. Recent research found that titanium-ceramic adhesion was improved when cast-titanium surfaces were subjected to chemical surface modifications.…”

“…13,14 The detrimental effect of the surface reaction layer on titanium-ceramic adhesion was reported in many cast titanium-ceramic bonding studies. [15][16][17][18][19] It has been proposed that the poor bond strength between porcelain and titanium was partly because of continual oxidation of titanium during the porcelain fusing and formation of a nonadherent oxide layer. 20 Thermodynamically, the equilibrium of titanium/oxygen system, based on the Ellinghams/Richardson diagram, 21 requires approximately 10 Ϫ110 to10 Ϫ90 atm of oxygen partial pressure between 400 and 800°C .…”

Cohesion and adhesion of nanoporous TiO2 coatings on titanium wires for photovoltaic applications

“…The mechanical resistance of the TiO 2 coating and its adhesion to the Ti substrate are therefore expected to play a key role in fiber performance. These properties are generally influenced by the roughness and cleanness of the substrate, the chemical affinity between the coating and the substrate, and the presence of cracks and other defects [7]. In the present case of a cylindrical geometry, a particularly important factor for the integrity of the interface between the Ti and the TiO 2 during deformation is expected to be the difference in Poisson's ratio (0.37 for Ti and 0.2 for monolithic TiO 2 ).…”