title: Synergistic cytotoxic effects of ions released by zinc-aluminum bronze and the metallic salts on osteoblastic cells.
abstract: The use of copper-based alloys for fixed dental crowns and bridges is increasingly widespread in several countries. The aim of this work is to study the dissolution of a zinc-aluminum-bronze and the cytotoxic effects of the ions released on UMR-106 osteoblastic cell line. Two sources of ions were used: (1) ions released by the metal alloy immersed in the cell culture and (2) salts of the metal ions. Conventional electrochemical techniques, atomic absorption spectroscopy [to obtain the average concentration of ions (AC) in solution], and energy dispersive X-ray (EDX) spectroscopy analysis were used to study the corrosion process. Corrosion tests revealed a strong influence of the composition of the electrolyte medium and the immersion time on the electrochemical response. The cytotoxicity was evaluated with (a) individual ions, (b) combinations of two ions, and (c) the mixture of all the ions released by a metal disc of the alloy. Importantly, synergistic cytotoxic effects were found when Al-Zn ion combinations were used at concentration levels lower than the cytotoxic threshold values of the individual ions. Cytotoxic effects in cells in the vicinity of the metal disc were also found. These results were interpreted considering synergistic effects and a diffusion controlled mechanism that yields to concentration levels, in the metal surroundings, several times higher than the measured AC value.
authors.affiliation: Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA, CCT La Plata-CONICET), Facultad de Ciencias Exactas, Departamento de Química, Universidad Nacional de La Plata, Casilla de Correo 16, Sucursal 4, 1900 La Plata, Argentina.
authors.forename: Claudia A
authors.initials: CA
authors.lastname: Grillo
authors.forename: María L
authors.initials: ML
authors.lastname: Morales
authors.forename: María V
authors.initials: MV
authors.lastname: Mirífico
authors.forename: Mónica A
authors.initials: MA
authors.lastname: Fernández Lorenzo de Mele
mesh_terms: D000165:Acridine Orange; D000535:Aluminum / Q000633:toxicity*; D000818:Animals; D001672:Biocompatible Materials; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003114:Colony-Forming Units Assay; D004396:Coloring Agents; D003300:Copper / Q000633:toxicity*; D003343:Corrosion; D016319:Corrosion Casting; D003722:Dental Alloys / Q000633:toxicity*; D004357:Drug Synergism; D004563:Electrochemistry; D009499:Neutral Red; D010006:Osteoblasts / Q000187:drug effects*; D051381:Rats; D012492:Salts / Q000633:toxicity; D013052:Spectrometry, X-Ray Emission; D013054:Spectrophotometry, Atomic; D014001:Tin / Q000633:toxicity*; D015032:Zinc / Q000633:toxicity*
chemical_list: D001672:Biocompatible Materials; D004396:Coloring Agents; D003722:Dental Alloys; D012492:Salts; D009499:Neutral Red; D014001:Tin; D003300:Copper; D000535:Aluminum; D000165:Acridine Orange; D015032:Zinc