Metal Alloys in Dentistry: Use and Properties

From the decline of precious alloys to the rise of cobalt-chromium and titanium, the properties that make each alloy suited to a specific clinical indication.

In the early days of dental technology, precious metal alloys — gold, platinum, palladium — were the near-exclusive choice for prosthetic restorations, valued for high corrosion resistance, biocompatibility and ease of working. The rising cost of precious metals and the search for more economically sustainable alternatives without sacrificing clinical quality led to the development of non-precious alloys, particularly cobalt-chromium, now widely used in current prosthetic practice.

Cobalt-chromium alloys offer an excellent combination of stiffness, specific strength and corrosion resistance, characteristics that make them the reference choice for removable partial denture frameworks and for porcelain-fused-to-metal substructures. The high elastic modulus of these alloys allows achieving thin connectors and frameworks without compromising rigidity, a non-secondary practical advantage in terms of patient comfort and bulk. Compared to nickel-containing alloys, cobalt-chromium also offers the advantage of generally being well tolerated even by nickel-allergic patients, a far from rare occurrence in the general population.

Titanium, particularly grade 5 alloy (Ti-6Al-4V, containing 6% aluminum and 4% vanadium), is today the reference material for dental implants and is also increasingly used in removable denture frameworks, where it significantly reduces the weight of the appliance compared to traditional cobalt-chromium, improves fit comfort and has less impact on the patient's taste perception. Titanium is generally considered one of the least allergenic metals overall, although rare cases of type IV hypersensitivity to the metal itself or to alloy components like aluminum or vanadium are documented.

Gold alloys for dental use, today reserved mostly for specific indications or patients with particular needs, typically contain a gold content between 45% and 55%, alloyed with other precious metals like platinum, palladium and sometimes iridium — the latter among the most expensive and hardest-to-refine metals overall, which further limits its use to cases where the specific properties of these alloys (high biocompatibility, excellent marginal fit) justify the higher cost compared to non-precious alternatives.

On Oralzon you'll find cobalt-chromium alloys, grade 5 titanium and gold alloys for prosthetic use, along with all the materials needed for working and finishing metal frameworks in the lab.