Dentists have been advised to use a metal composite which uses platinum, palladium, iridium and ruthenium when choosing crowns for patients' teeth.

According to Dr Michael DiTolla, director of clinical research and education at Glidewell Laboratories in California, using a gold composite combined with the various platinum group metals (pgms) can significantly overcome most of the problems found in the use of crowns.

Dr DiTolla explains in Dental Economics that a composite which is 88 per cent gold, four per cent platinum, four per cent palladium, one per cent iridium and one per cent ruthenium can improve a porcelain crown by acting as its substructure.

The platinum-palladium-gold alloy particles are impregnated onto a wax sheet which is used to coat the refractory die.

When this die is then placed in a porcelain oven, the alloys fuse together to create a sintered, porous, solid metal coping, with the wax having been eliminated. The high nobility of the coping means that there is little likelihood of allergic reactions occurring, making it a safe and effective approach to giving people crowns.

The crowns also have less bacteria build-up than other types, Dr DiTolla claims.

Ÿ Adfero Ltd