Corrosion Behaviour of Ceramics and Dental Alloys

The corrosive nature of saliva in human mouth requires the degrees of restraint to achieve maximum material safety. The corrosion parameters of dental alloys in the oral cavity are still widely discussed despite a great development of non-metallic materials. Our aim was to verify the release of elements from the saliva and determine their exact level by GF-AAS and ICP-MS.

Methods:

Four chrome-nickel dental alloys, dental alloy based on titanium (TiNbAl-Ti 86 %), noble alloy (AuAg) containing 77 % of gold and different types of ceramic materials (zirconia, alumina) were selected. The saliva was analyzed after delivering simulated denture for the corrosion behaviour of the materials.

Results:

Chromium release depends on the dental alloy composition and the time after delivering simulated denture. The nickel release depends on the delivering time only. Comparing zirconia and alumina ceramic material, the value of released ions is less in zirconia. The overvalue of dental alloys corrosion (the release of the nickel and chromium ions) in comparison with the corrossion values for all-ceramic material (the release of aluminium and zirconium ions) and also for dental alloy based on titanium was demonstrated.

Conclusion:

Analyzed dental alloys could be used for dental denture manufacturing, differences in chromium and nickel concentrations were found in the saliva. The presence of released ions in the saliva was also documentated in ceramic materials. None of the known dental materials can preserve absolute resistance against all corrosion forms. Acidity of the saliva can notably influence the concetration of released ions.

Supported by Internal Grant Agency of Ministry of Health, Czech Republic No. 9744-3