Groosman, the father of endodontics, divided root canal treatment before 1976 into four stages. These four stages are collectively referred to as modern root canal treatment. After 1976, it is called contemporary root canal treatment. The concept of treatment has already undergone tremendous changes, which can be summed up in two sentences: "completely remove the original infection in the root canal system to prevent the introduction of new infection; strict filling of the root canal system and good coronal sealing to prevent re-infection". Anything contrary to this principle should be avoided as much as possible in the process of root canal treatment.
Random opening of the root canal during root canal treatment is not allowed in modern root canal treatment for the following reasons:
1. There are generally only 7 to 8 kinds of bacteria colonized in the infected root canal (in most cases, only 4 to 6 kinds), while there are more than 300 kinds of bacteria in the oral cavity (in addition, there are more than 200 kinds of bacteria in the literature), and the opening will introduce new bacteria into the root canal.
2. Among infected root canals, 70% to 80% of the infection is usually only located in the middle and upper segments of the root canal. Opening the root canal after root canal preparation will contaminate the originally "clean" middle and lower segment of the root canal.
3. The colonization of bacteria in the infected root canal was originally in a redox potential equilibrium. After the root canal preparation, the restraining effect between the bacteria was weakened, and the opening of the root canal easily made the "oral bacteria" entering the root canal lose control and proliferate rapidly.
4. The bacteria in the infected root canal are generally gram-negative bacteria, which are rare. A large number of literature reports that many cases of failure after complete root canal treatment are due to the detection of gram-positive bacteria in the root canal, especially the root canal infected by Enterococcus faecalis is almost an indication for tooth extraction.
1. Acute and chronic pulpitis: In fact, in most cases of pulpitis, the inflammation is limited to the coronal pulp. After pulping under local anesthesia, calcium hydroxide is used to seal the drug. One-time root filling is now the mainstream.
2. Acute and chronic periapical inflammation without abscess at the root tip: Pay attention to the principle of asepsis. In the case of complete derotation, the pulp can be opened (in cases where the pulp is not exposed, the pulp can be opened after changing a clean bur after the derotation is completed), the roof is removed, and edta, sodium hypochlorite are used to remove the infection in the pulp cavity, and there is a protaper device. If you don't have the option, you can start the preparation for debridement with the coronal in-depth method. If you don't have it, use the K-tumbler to dredge the root canal. Don't use the lifting method, this is the main reason for the pain after sealing the medicine, as for the balance force method, we will talk about it in another post), measure the length with the apex locator, cooperate with edta, and a large amount of flushing is the key point. Prepare to be one or two sizes larger than the initial setback, and you can seal the medicine with calcium hydroxide. You can add an appropriate amount of iodoform.
3. When an abscess is formed by periapical periodontitis, and the abscess is a subperiosteal or submucosal abscess: the root canal is prepared as in the case of no abscess. The difference is that the final incision needs to be made on the buccal side of the abscess. Depending on the size of the abscess, a drainage strip can be selected.
4. Periapical abscess, abscess limited to the root tip: This is the most complicated situation. If a smooth apical foramen drainage can be established (usually only anterior teeth can do this), it can be sealed after a large number of NS rinsing in clinical practice. So, the more extreme approach is to drill the cortical bone for drainage under local anesthesia, and we choose to open the root canal ( If the patients need cortical cortical drilling, they probably choose to pull out the tooth), which requires opening root canal. The second situation in which root canal opening is when the patient is in the acute inflammation stage, and the open drainage is combined with anti-inflammatory drugs to relieve the acute inflammation and then the root canal is removed.