Gold restoration cemented with zinc polycarboxylate usually fractures at which interface?
Zinc polycarboxylate has ability to bond chemically with tooth structure so less chance of failure at tooth cement inteface
In case of gold restorations usually adhesive failure occurs at the interface b/w gold & cement
In case of non-precious metals usually cohesive failure occurs b/w cement layer itself.
Cement-prosthesis
Cement itself
Tooth structure - cement
Prosthesis failure