Prefabricated crowns made of tin-silver alloy for short-term adult posterior use. Refills of individual permanent crowns are available in boxes of five. 3M ESPE U41 ISO-Form Temporary First Bicuspid Crown, Upper Left, Tin-Silver Alloy, Size 6.4, Pack of 5. Pre-finished, contoured and belled to save placement time. Soft tin-silver alloy retains shape of preparation and is easily stretched and burnished to fit prep margins. Bicuspid and molar crown selection to cover adult posterior applications. Faster placement than acrylics and chemical resin for single units for a quicker procedure. Crown set is packaged in a unique, stackable tray that provides convenient, easy storage of prefabricated crowns.