Resin-containing Ca(OH)2 has which level of cytotoxicity?

• A. severe cytotoxicity
• B. no cytotoxicity
• C. moderate cytotoxicity
• D. low cytotoxicity

Answer: (C)

Resin-containing calcium hydroxide liners bring together the bioactive action of calcium hydroxide with resin components. The calcium hydroxide part remains highly alkaline, which can irritate cells, while resin monomers that may leach out (especially if polymerization isn’t complete) can also affect cell viability. The combination tends to produce some adverse cellular effects, but not to a severe degree. So the material is best described as having moderate cytotoxicity: it’s not completely non-toxic, but it doesn’t cause widespread cell death either. This level reflects the balance between the bioactivity that supports healing and the potential cytotoxic effects from resin components.