Gold restoration cemented with zinc polycarboxylate usually fractures at which interface?: (A) Cement-prosthesis, (B) Cement itself, (C) Tooth structure - cement, (D) Prosthesis failure
Answer is A. 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.