what do you know about cavity preparation?
Cavity refers to the removal of carious tissue by dental surgery and the preparation of the cavity as required. The cavity has a certain shape and can accommodate and support the filling material to achieve the purpose of restoring the shape and function of the tooth.
The basic steps of cavity preparation
1.Opening and expanding the cavity or searching for the entrance: for the cavity with hidden lesions, the opening and searching for the entrance should be first opened and expanded to fully expose the cavity or form a pathway for surgical operation, so as to facilitate observation and operation. The baseless enamel at the edge of the cavity can be removed by a crack drill or diamond bur, and the cavity can be opened and expanded according to the lesions, or a groove can be made from one side of the cavity with a crack drill to form a surgical pathway.
2.Removal of rot: When the lesion scope is large, the rot should be removed first. The food residue and most of the rot in the cave can be removed with a digging spoon first, then the rot around the edge of the cave can be removed with a diamond bur, and finally the rot at the bottom of the cave can be removed. The removal and retention of a small amount of softened dentin near the medullary cavity at the bottom of the cavity should depend on the actual situation.
3.Design and prepare the shape of the cavity: The cavity edge line constitutes the shape of the cavity. Although all kinds of holes have basic shape requirements, the preparation of cavity shape should also take into account the scope of lesion destruction. The shape of the cavity should be designed according to the lesion range after the removal of the rot. The cavity should include all the diseased sites, and the cheek (lip) and tongue walls should reach the self-cleaning area. The shape of the cavity should conform to the basic principles of retentive shape and resistant shape. Do not wear away too much healthy tooth tissue during preparation.
4.Repair the cavity shape and clean the cavity: After the completion of the cavity shape preparation, the dentin debris in the cavity should be removed, and the cavity parts should be carefully checked to see whether the rot has been removed and whether the resistance shape and retention shape meet the requirements. If it does not meet the requirements, it should further remove the rotting material and modify the cavity shape to meet the requirements. Finally, the enamel at the edge of the hole is trimmed to align with the glaze column, and the hole is thoroughly cleaned to remove all debris.
5.Cavity disinfection: After the cavity preparation, there will inevitably be a small amount of bacteria in the dentin tubules. The ideal disinfection drug can not only kill the bacteria in the tubules but also not damage the pulp of the tooth, which is undoubtedly beneficial to the disinfection of the cavity. But the disinfection drugs used at present cannot meet the above requirements. Therefore, it is far more important to get rid of the rot than to disinfect the cavity. Most of the bacteria can be removed by removing the rotten material. Even if a small amount of bacteria remains, they will gradually lose their activity ability or die after a certain period of time due to the unfavourable environment after filling and repairing.
