Losing a tooth due to decay, damage, or gum disease can happen to anyone. Many people question why they need to have it replaced, especially if it is a back tooth. The reason dentists recommend replacing the tooth is because a missing tooth can cause other dental problems. For one, your other teeth may shift out of place or become loose due to the empty space. Also, the jaw bone that once held the tooth in place can resorb and cause a weak spot in your jaw. You can avoid these related issues by replacing the tooth with a dental implant.