Why should I replace missing teeth?
Your appearance is one reason. Another is that the gap left by a missing tooth can mean more strain is put on the teeth at either side. A gap can also mean your ‘bite' is affected, because the teeth next to the space can lean into the gap and change the way the upper and lower teeth bite together. This can then lead to food getting packed into the gap, which causes tooth decay and gum disease.
The main alternatives are a fixed bridge or a dental implant. A dental bridge is made by putting crowns on the teeth at either side of the gap, and then joining these two crowns together by placing a false tooth in the space. This is all made in the laboratory and then the pieces are cemented into place with special adhesives. The bridge can't be removed.