Before revision: In the case of partial necrosis, access to and into dentine would be needed, with the dentist progressively invading and drilling deeper into dentine, checking the sensory response -- which is usually without sensory response because of the partial necrosis.
After revision: In the case of partial necrosis, access to and into dentine would be needed, with the dentist progressively invading and drilling deeper into dentine, checking the sensory response — which is usually without sensory response because of the partial necrosis.