If a cavity is hollowed out, it is definitely much more difficult to pull out the tooth, because after the cavity is hollowed out, the exposed part of the crown of the tooth is hard to withstand the force, and it will be shattered with a little force, so it is difficult to pull out the roots of the tooth together, and the top cavity has to be removed first, and then the roots are dug out little by little. Imagine, if you want to pull a radish, you must grab the radish with both hands and shake it slowly to pull out the radish and the roots in the soil together, if the radish is hollowed out and only a layer of shell is left, imagine a grasp, the radish on the ground will be broken, not to mention pulling out the whole radish intact, so try not to wait until the tooth decay is empty before pulling out the tooth.