When teeth have been missing for some time the bone and gums can begin to change shape. This can affect surrounding teeth.
Once a tooth is lost, the bone and gum will begin to recede. If you later decide to have an Implant fitted it may mean that the Implant would sit too high or the Crown would sit too low for your 'bite'. A material can be inserted into the cavity to encourage bone re-growth. Over time, this will provide a sufficient amount of bone to support the Implant.