title: Letter: The FDA responds to the use of N-2 and RC-2B.
mesh_terms: D005557:Formaldehyde; D012387:Root Canal Filling Materials / Q000592:standards*; D012390:Root Canal Therapy / Q000379:methods; D014481:United States; D014486:United States Food and Drug Administration
chemical_list: D012387:Root Canal Filling Materials; D005557:Formaldehyde