Dental Gold & bonding alloys
We purchase and process in any condition gold, palladium, platinum dental crowns, bridges, posts, inlays, precious implant components, precious orthodontic braces and dental laboratory precious metals. In addition we also purchase refined bullion and Assay Office bars, ingots and cones.
Historically high gold content alloys were favoured for dentistry because of their acid resistance and their softness which facilitated ease of manufacture of units. Softness was of course also its drawback and small quantities of platinum were alloyed with gold to produce harder materials. Subsequently palladium, a then more economic platinum group metal, was used as the hardening element.
Towards the end of the last century small higher temperature furnaces became widely available and the use of palladium alloy, generally termed bonding alloy, became popular. Technical advances have enabled coefficients of expansion in palladium alloys and the dental porcelain materials to be matched so greatly improving the bonding.
Yellow dental scrap in the UK could be as high as 93% gold and 75% gold was quite common. Today UK dental scrap often reflects the historic categories of NHS approved alloys which stated particular minimums of precious metals content.
10D1/10DI = minimum of 60% fine gold content but with no maximum and most of those alloys contained 60% gold + 3 or 4% palladium as a hardening element, 10D2/10DII = minimum 45% fine gold content and these usually contained 45% gold + 20 to 45% palladium. Then as the bonding properties of palladium alloys became appreciated a subsequent 10D3/10DIII category was approved, initially the most popular form contained only 30% palladium plus 45% to 50% silver but these were superseded by higher palladium content alloys.
- Current yellow dental gold - gold content ranges 20% to 93%
- Current white dental gold - gold content ranges 45% to 58%
- Current palladium bonding materials - palladium content ranges 30% to 80%