Basically, there are three layers of a tooth- Enamel(the outermost layer) , Dentin(the middle layer) and Pulp(the nerve of the tooth). When a cavity has already involved the pulp i.e. the nerve and the patient has started facing irreversible symptoms specially pain on lying back at night, difficulty in chewing food from that particular side and sensitivity to hot and cold beverages which lingers even after removal of stimulus, then restoration (filling) cannot be performed and RCT is the ultimate treatment plan. In these cases, if RCT is not performed at the earliest, then the cavity may extend to more deeper layers and cause root caries. Root caries calls for extraction of the tooth. So if you want to save the tooth and if you have started facing mild to moderate symptoms as mentioned above, then don’t think twice and believe in us.