Author/Authors :
Dave, V Department of Dental Materials - Manipal College of Dental Sciences Mangalore - Manipal Academy of Higher Education - Manipal - Karnataka, India , Kotian, R Department of Dental Materials - Manipal College of Dental Sciences Mangalore - Manipal Academy of Higher Education - Manipal - Karnataka, India , Madhyastha, P Department of Dental Materials - Manipal College of Dental Sciences Mangalore - Manipal Academy of Higher Education - Manipal - Karnataka, India , Boaz, K Department of Oral Pathology and Microbiology - Manipal College of Dental Sciences Mangalore - Manipal Academy of Higher Education - Manipal - Karnataka, India , Rao, P Department of Chemistry - Manipal Institute of Technology, Manipal - Academy of Higher Education - Manipal - Karnataka, India , Charitha, B. P School of Graduate Sciences - JC Road Campus - Jain University - Bangalore, India
Abstract :
The aim of the present study was to assess the hardness, corrosion, and cytotoxicity of a commercially
available cobalt-chromium (Co-Cr) alloy before and after simulated heat treatments at porcelain ring temperature. Five
Co-Cr samples were fabricated using a lost wax casting procedure. Heat treatments were carried out at 650 °C, 750 °C,
850 °C, and 950 °C. Vickers hardness was measured for as-cast and heat-treated samples. The corrosion test was carried
out separately in 0.1 N NaCl, 1% citric acid and articial saliva at room temperature using potentiodynamic polarization
technique. Gingival tissue biopsy of patients was taken and cultured to measure the cell viability by MTT colorimetric
assay. Lowest hardness was observed at 650 °C. 0.1 N NaCl and 1% citric acid corrosion medium showed a similar trend
of corrosion rate. The least corrosion rate was found in articial saliva. Firing temperature has an impact on the physical,
chemical, and biological properties of Co-Cr alloy in long-term clinical use.
Keywords :
Cobalt-chromium , Heat treatment , Corrosion , Cytotoxicity , Hardness
