Elements released from dental casting alloys and their cytotoxic effects

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Toxicology

Background:

• Dental casting alloys are crucial in prosthodontics.
• Understanding their elemental release and cytotoxicity is vital for patient safety.
• Various alloy compositions exist, including high-noble and base-metal types.

Purpose of the Study:

• To investigate and compare element release from seven commercial dental casting alloys.
• To evaluate the cytotoxic effects of these alloys on Balb C fibroblasts.
• To correlate alloy composition with observed element release and toxicity.

Main Methods:

• In vitro study using one high-noble and six base-metal alloys (Ni-Cr, Co-Cr, Cu-based).
• Specimens conditioned in distilled water at 37°C for 72 and 168 hours.
• Element release analyzed in conditioning media; cytotoxicity assessed via MTT assay on fibroblasts.

Main Results:

• Element release increased significantly with longer conditioning times (168 vs. 72 hours).
• High-noble alloy showed minimal Zn release and no cytotoxicity.
• Cu-based (Thermobond) and Ni-Cr (CB Soft) alloys exhibited the highest element release and significant cytotoxicity.
• Co-Cr alloy (Wirobond C) was more cytotoxic than the high-noble alloy.

Conclusions:

• Element release from dental casting alloys is time-dependent.
• Chromium (Cr) and Molybdenum (Mo) content appear protective against dissolution.
• Copper (Cu) content increases susceptibility to corrosion, leading to higher cytotoxicity.