Depending on the damage caused to the dead tooth, it could fall out in weeks or months. However, it is not recommended that the patient wait that long. If a tooth dies or rots with decay, you should visit your dentist as soon as possible. A number of factors can influence how quickly tooth decay progresses, including oral hygiene, diet, and more.
However, most cavities take several months or years to form. Technically speaking, tooth decay can destroy enough of a tooth to eventually fall out. However, even if the tooth remains, it may need to be removed if you wait long enough to treat the cavity. When decay reaches the center of the tooth, or pulp chamber, bacteria can travel through the connected root canals, significantly worsening the condition.
If endodontics isn't enough to save the tooth, then extracting it may be the only way to protect the rest of your smile. While most cavities develop over a period of months or years, poor oral hygiene can dramatically accelerate the progression of tooth decay. Tooth abscesses occur when the bacteria that cause cavities continue to spread below the tooth pulp.