<prompt> zone which is absent when repair is done with MTA as compared to calcium hydroxide:Zone of calcificationZone of necrosisZone of vascular inclusionNone of the zone is absent  <response>: Zones formed with calcium hydroxide CH pulp therapy from below CH to normal pulp are:Zone of liquefactive necrosisZone of coagulative necrosisInflammatory responseHard tissue barrier with vascular inclusions.The necrosis with pure CH is due to its high PH. But dycal which is a hard setting CH formulation forms hard tissue barrier without causing necrosis.Zones formed with MTA pulp therapyVery narrow or even absent coagulative necrosisReparative dentinogenesis zone resulting in dentin bridge with fewer vascular inclusion high quality.MTA is a biocompatible material. The excellent bacteria-tight seal accounts for the success with MTA. 