title: Ni-Cr based dental alloys; Ni release, corrosion and biological evaluation.
abstract: In the last years the dental alloy market has undergone dramatic changes for reasons of economy and biocompatibility. Nickel based alloys have become widely used substitute for the much more expensive precious metal alloys. In Europe the prevalence of nickel allergy is 10-15% for female adults and 1-3% for male adults. Despite the restrictions imposed by the EU for the protection of the general population in contact dermatitis, the use of Ni-Cr dental alloys is on the increase. Some questions have to be faced regarding the safety risk of nickel contained in dental alloys. We have collected based on many EU markets, 8 Ni-Cr dental alloys. Microstructure characterization, corrosion resistance (generalized, crevice and pitting) in saliva and the quantities of cations released in particular nickel and CrVI have been evaluated. We have applied non parametric classification tests (Kendall rank correlation) for all chemical results. Also cytotoxicity tests and an evaluation specific to TNF-alpha have been conducted. According to the obtained results, it was found that their behavior to corrosion was weak but that nickel release was high. The quantities of nickel released are higher than the limits imposed in the EU concerning contact with the skin or piercing. Surprisingly the biological tests did not show any cytotoxic effect on Hela and L929 cells or any change in TNF-alpha expression in monocytic cells. The alloys did not show any proinflammatory response in endothelial cells as demonstrated by the absence of ICAM-1 induction. We note therefore that there is really no direct relationship between the in vitro biological evaluation tests and the physico-chemical characterization of these dental alloys. Clinical and epidemiological studies are required to clarify these aspects.
authors.affiliation: PX Holding S.A., Dep R&D Corrosion and Biocompatibility Group, Bd. des Eplatures 42, CH-2304 La Chaux-de-Fonds, Switzerland.
authors.forename: L
authors.initials: L
authors.lastname: Reclaru
authors.affiliation: Institute for Pathology, REPAIR Lab, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstr.1, D-55101 Mainz, Germany.
authors.forename: R E
authors.initials: RE
authors.lastname: Unger
authors.affiliation: Institute for Pathology, REPAIR Lab, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstr.1, D-55101 Mainz, Germany.
authors.forename: C J
authors.initials: CJ
authors.lastname: Kirkpatrick
authors.affiliation: PX Holding S.A., Dep R&D Corrosion and Biocompatibility Group, Bd. des Eplatures 42, CH-2304 La Chaux-de-Fonds, Switzerland.
authors.forename: C
authors.initials: C
authors.lastname: Susz
authors.affiliation: PX Holding S.A., Dep R&D Corrosion and Biocompatibility Group, Bd. des Eplatures 42, CH-2304 La Chaux-de-Fonds, Switzerland.
authors.forename: P-Y
authors.initials: PY
authors.lastname: Eschler
authors.affiliation: PX Holding S.A., Dep R&D Corrosion and Biocompatibility Group, Bd. des Eplatures 42, CH-2304 La Chaux-de-Fonds, Switzerland.
authors.forename: M-H
authors.initials: MH
authors.lastname: Zuercher
authors.affiliation: Materials Science and Engineering Faculty, Politehnica of Bucharest, 060042 Bucharest, Romania.
authors.forename: I
authors.initials: I
authors.lastname: Antoniac
authors.affiliation: Institute of Dental Materials Science and Technology, University of Basel, Hebelstrasse 3, CH-4056 Basel, Switzerland.
authors.forename: H
authors.initials: H
authors.lastname: Lüthy
mesh_terms: D045744:Cell Line, Tumor; D002858:Chromium Alloys / Q000009:adverse effects / Q000737:chemistry*; D003722:Dental Alloys / Q000009:adverse effects / Q000737:chemistry*; D004563:Electrochemistry; D042783:Endothelial Cells / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008422:Materials Testing; D009000:Monocytes / Q000378:metabolism; D009532:Nickel / Q000009:adverse effects / Q000737:chemistry*; D012463:Saliva / Q000737:chemistry; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D002858:Chromium Alloys; D003722:Dental Alloys; D014409:Tumor Necrosis Factor-alpha; D009532:Nickel