Why replace teeth?
Missing teeth have a number of implications.
There is the obvious issue of appearance at sites where the gap is visible.
Gaps in the Dental Arch create instability. Much like in the world of building/construction an arch is a very stable structure whilst intact. If a component of an arch is lost it becomes unstable
Gaps in the mouth from missing teeth allow movement of teeth, especially teeth immediately next to gaps but also all of the teeth in the dental arch once it is unstable.
The resultant tooth movements mean spaces appear between teeth resulting in food traps and making cleaning of the teeth more difficult. The effect of this is the increased likelihood of tooth decay and gum problems.
The teeth opposing a gap (in the other jaw which bite onto a gap) will move if the contact on biting together is lost. This results in overgrowth of the unopposed tooth which leads to further potential for decay and gum problems.