An 8-year-old girl complains of tooth 21 discoloration and pain response to hot stimulus. Several months ago tooth 21 was treated for acute diffuse pulpitis by means of vital amputation. Objectively tooth 21 is ?lled, percussion is painless. X-ray shows the rooth to be formed by 2/3, cortical plate of the tooth socket remains intact in the area of root radix. What material should be used for root canal ?lling in this case?