Yes, you need to replace it. In most cases replacing a missing tooth is important to prevent neighbouring teeth from shifting. Shifting teeth create areas that are difficult to keep clean and can lead to gum problems and teeth decay. Also, when teeth shift and no longer fit together properly, causes excessive wear, headaches, and many other problems.
Ideally, dental implants or bridges replace missing teeth. Dental implants replace the root of the tooth. Implants are made of titanium and are placed in the bone. After healing, a crown is placed on the implant. Implants don’t decay and typically last a long time. Implants are the best restoration in cases where the neighboring teeth are healthy and properly aligned.
A bridge may be the best option if the neighboring teeth are unhealthy. Replacing a tooth with a bridge involves reshaping neighboring teeth to which the bridge will attach. The cost of a three-tooth bridge will probably come close to the combined cost of the implant placement and implant crown.
Obviously, many considerations are taken into account with each patient when deciding how to replace a missing tooth. Ask your dentist what he or she would do if they were in your situation. That will help you with your own decision.