The tooth consists of three layers.
When the decay is superficial in enamel or upper part of dentin, the dentist removes the decay and fills the cavity with a tooth colored filling material. When the decay reaches the inner part of the dentin or the pulp the patient feels continuous throbbing pain or pain that lingers for few minutes or hours even after removal of hot or cold stimulus. Many times the pain increases during night. Sometimes there is a pain to touch or pain on biting. In most of these cases a root canal is indicated if the tooth is salvageable. Many times root canal is needed in cases of deep cracks in the tooth.
Dentists specialized in root canal treatments are called Endodontists. Root canal is a procedure of saving a natural tooth. It allows the tooth to function in the oral cavity for rest of your life. Before proceeding for the root canal treatment the dentist may take radiograph of your teeth or perform various tests like vitality testing to come to a final diagnosis. Once confirmed the dentist numbs your tooth with a local anesthesia. A small rubber sheet called rubber dam is applied on the teeth to prevent contamination and also for patient protection. Then the dentist removes the decay and creates a small opening in the tooth. After this all the infected tissue is removed from the tooth with special instruments and disinfectant solutions. Sometimes if the infection is more, intracanal medicament is placed for a week or two to achieve better disinfection. After this the empty space is filled with a material called gutta percha followed by cement. Root canal is a completely painless procedure and requires around one to one and half hour. It can be completed in single visit or may need multiple visits depending on the situation and amount of infection. Most of the cases need crown coverage after the root canal. Due to advancement in technology and materials like dental operating microscope, different agitation systems, thermoplasticised obturation, bioceramic sealer, MTA etc, success rate of root canal has increased.
It is a routine dental procedure and does not require any rest. You can go back to your routine work after the treatment. Immediately after treatment you have to avoid foodstuffs that require chewing or hot food till the anesthesia wears off. Your dentist might instruct you to avoid eating hard food till the final coronal restoration or crown is placed. Daily brushing and flossing and annual dental check up should be done to prevent further complications.