Root canal treatment is, simply said, extraction of the nerve and a root canal filling of the tooth. An untreated cavity that spreads reaches the edge of the dental nerve and causes the inflammation. Nerve inflammation can pass without symptoms (it spreads and nerve necrosis occurs) or with symptoms such as: cold-stinging pain or pulsing of the tooth (especially at night). The endodontic procedure must be carried out under sterile conditions with as little bacteria possible, as we are interested of thoroughly purifying the bacteria from the tooth canal. When we have removed the nerve and cleaned the canal, we have to fill it, to the sealing of the canal and make a final filling or dental crown.