Abstract: Metallic materials, such as Co–Cr–Mo alloys, are exposed to aggres-
sive conditions in the oral cavity that represents an ideal environment for
metallic ion release and biodegradation. The metallic ions released from dental
materials can cause local and/or systemic adverse effects in the human body.
Therefore, dental materials are required to possess appropriate mechanical,
physical, chemical and biological properties. The biocompatibility of metallic
materials is very important for dental applications. Accordingly, the aim of this
study was to examine metallic ion release and cytotoxicity of Co–30Cr–5Mo
cast alloy as the initial phase of biocompatibility evaluation. Determination of
the viability of human (MRC-5) and animal (L929) fibroblast cells were
conducted using three in vitro test methods: the colorimetric methyl-thiazol-
tetrazolium (MTT) test, the dye exclusion test (DET) and the agar diffusion test
(ADT). Furthermore, the morphology and growth of the cells were analyzed
using scanning electron microscopy (SEM). The obtained results indicated that
Co–30Cr–5Mo alloy did not release harmful elements in concentrations high
enough to have detrimental effects on human and animal fibroblasts under the
given experimental conditions. Moreover, the fibroblast cells showed good
adhesion on the surface of the Co–30Cr–5Mo alloy. Therefore, it could be con-
cluded that Co–30Cr–5Mo alloy is a biocompatible material that could be
safely used in dentistry.