If you have missing teeth, or are about to loose teeth, then filling the gaps can be achieved with a denture, bridge or implants. To some, dentures are a bit old fashioned, perhaps something that their grandparents might have worn, and they involve the hassle of removal and cleaning. Sometimes dentures, in addition to the plate, have unsightly clasps to help hold them in place.
Most fixed bridge involve preparing teeth each side of the gap to support the bridge. Once the teeth are prepped then it cannot be reversed. It is a shame to sacrifice some good tooth structure to replace a missing tooth elsewhere.
A major disadvantage with both dentures and bridges is that they fail to preserve the underlying bone and gum around the extracted teeth sites. The gum will continue to shrink throughout life, giving an aging effect. Dental implants, on the other hand, feel just like normal teeth, do not involve the cutting of adjacent teeth, are a much more permanent solution, and help prevent the aging effect.