<prompt> A 40 year old male patient complains of decayed tooth. Patient gives history of class I cavity preparation and restoration with conventional amalgam with 26. Intra-oral examination reveals proximal caries with 26. The copper content of the restoration done in this patient is?2-5612-309  <response>: Low-copper amalgam alloys contain 2 to 5 copper. The earliest successful amalgams were made by combining filings of such alloys with mercury. A typical modern low-copper amalgam alloy may contain 69.4 Ag, 26.2 Sn, 3.6 Cu, and 0.8 Zn. Amalgams made from such low-copper alloy filings are often referred to as conventional amalgams. High-copper amalgam alloys contain 12 to 30 copper, and because of their higher copper content, they display significantly better corrosion resistance than low-copper amalgams.Reference: Sturdevants Art and Science of Operative Dentistry, Mosby, 4th Edition, Page No: 149 