Root canal therapy or treatment is done when your cavity is very deep and close to pulp chamber.  Pulp chamber is where your blood n nerve vessels are. So when your caries is close to pulp chamber you feel pain. But when it involves pulp chamber tooth becomes dead . So in RCT we remove the whole pulp chamber n clean it with medicament . N place fillings there . But because our teeth goes through lots of drilling. Half of tooth structure goes.  So we suggest placement of cap. RCT gives 90% success . Only in few cases it shows reinfection

Side effect not as it is. Risk is reinfection sometimes Failure rate of treatment is 10-15%, which is considered fairly great. Rct and  capping is done to save the tooth and prolong the life of it.

Hi RCT is the teeth saving procedure....it has to be done once the infection of the teeth reaches pulp(blood vessels and nerves)... It has to be done in 2 sittings....The tooth is drilled and the inner root canal has to be cleaned to eliminate the infection(removes all nerves and blood vessels) and then shaping the root canal and filling the root canal with Guttapercha point)....it is must to do capping after root canal treatment which also improves chewing capacity of the teeth....There is no side effects with this procedure .... If you left the teeth untreated even after the infection reaches deeper in the teeth,it can progress and causes infection at root apex,surrounding bones which causes bone erosion and resultant swelling in the face... An alternative to root canal is Extraction of the teeth...But removing one teeth will weekend the three nearby teeth and the neighbour teeth will tries to move to fill the gap and it gets weekends...Moreover removing one molar teeth will reduce the chewing efficiency by 50%