A biomaterial used oral cavity should not become toxic, irritant, carcinogenic, and allergenic. Chitoson represents a new biomaterial in dentistry. To examine the toxicity of chitosan from tiger prawn shell waste on cell culture with MTT assay. Chitosan with concentration of 0.25%, 0,5%, 0.75% and 1% was used in this experiment Each sample was immersed on eppendor microtubes containing media c…