The purpose of root canal retreatment is to heal the tooth by removing the pulp and restoring the physiological function of the endodontic tissue. Before root canal treatment, the soft tissues of the apical area must be cleaned. The untidy and bacterially contaminated parts of the root tip are removed.
Initial cleaning with an apical file is required for root canal retreatment in order to remove foreign bodies such as gum and gum fragments from the root. Root canal filling materials must also be treated with root canal retreatment before use.
Methods and requirements for the use of apical files：
When using a root-tip file, it is required that no foreign material is left in the root canal. First hold the file with your right hand, then hold both ends of the pliers with your left hand. Then press downward with the left hand so that the tip of the file enters the root canal (not into the root canal) until the tip of the file reaches the root. The tip of the file should be as close or as close to the inner wall of the root canal as possible to facilitate the operation.
Precautions：
(1) When removing gum scale from the root canal wall with an apical file, do not over-abrade the tooth, as too much grinding can cause dentin demineralization or even dentin perforation.
(2) Do not easily peel off the gum and resin materials by hand to prevent damage to the gum tissue during root canal cleaning.
(3) Be careful not to damage the gingival tissue by excessive force.
(4) Do not repeatedly clean the root canal files to avoid damaging the gingiva or causing other infections.
(5) Be careful not to get the tips of the files into the root tips and to stick the gum in the root canals together.
