Titanium-porcelain system. Part IV: some mechanistic considerations on porcelain bond strengths.
The titanium-porcelain system can be considered as a double-layered structure, comprising of at least titanium substrate and porcelain body including bonding agent. Stress distribution pattern of such a double-layered structure is not necessarily same as that of a single beam under the 3-point bending testing mode. Previously tested porcelain-fired commercially pure titanium samples (n = 285) were re-evaluated. All obtained data on bond strengths and bond toughness (energy-to-break) were re-grouped in terms of c/t ratio, where c is the distance from the maximum compressive side of the beam to the calculated neutral axis and t is the thickness of titanium substrate plate thickness. It was found that (1) when the double-layered structure falls in the c < t situation, both bond strength and bond toughness are in a lower zone, which is slightly lower than the cohesive tensile strength of the porcelain, (2) when the c > t situation (with relatively thick porcelain application) is established, both bond strength and toughness are in higher zone than the porcelain itself, and (3) there is a transition zone between the above.
Oshida
Y
Y
Department of Restorative Dentistry, Indiana University School of Dentistry, Indianapolis 46202-5186, USA. yoshida@iupui.edu
Reyes
M J
MJ
D001840:Dental Bonding; D003776:Dental Porcelain; D006801:Humans; D066298:In Vitro Techniques; D008422:Materials Testing; D013314:Stress, Mechanical; D013499:Surface Properties; D014025:Titanium
D003776:Dental Porcelain; D014025:Titanium