Broken teeth can be caused by trauma or significant decay that has weakened the tooth structure to the point that it crumbles during normal use. Large restorations can lead to weakening of the tooth and possible fractures. The severity of the break and the condition of the remaining tooth will determine what procedures can be provided. With small fractures conservative treatment such as tooth colored fillings can be done to restore missing tooth structure.
Larger fractures may require additional procedures such as a build up with a crown. The tooth could fracture and be so compromised that the only options are root canal with crown or complete removal of the tooth. Extraction of the tooth may lead to shifting teeth that could later result in problems with bite or even compromising the other teeth.
To avoid other problems replacement of missing teeth should be discussed with your dental professional.