Hi doc, what is the most reason to get back lower tooth pulled out or there is some remedy ?

Many reasons: The tooth may be hopeless & need to be extracted because of a root fracture, coronal fracture into the floor of the pulp chamber, periondontal (gum) disease with insufficient & un-repairable bone loss, or decayed too far below the level of the crest of bone to make it salvageable. The last reason would be a patient who could not afford to have it fixed or wise enough to try to save it, if possible.

Always best: To try to save teeth. Circumstances such as extensive decay, extensive tooth loss, associated bone loss or gingival tissue loss, economic reasons ..... Etc can result in necessitating the removal of the tooth. But if treatment is possible with an affordable and predictable outcome, always better to save than lose. Hope this helps.

A few: There are a number of indications for extraction of teeth. Hopeless decay or periodontal disease, trauma, insufficient room, malalignment. If serviceable, best to save most teeth. Ask your dentist about your situation.