Fifty-eight papers reporting survival rates of single implants were selected by use of the 'PubMed' and hand searching. The survival rate of single implants were assessed with reference to factors influencing osseointegration.

The results showed that single implants in general showed a high survival rate except a few failures in certain extreme conditions and early stages. Those failures and complications such as screw loosening and esthetic problem were almost solved with the development of implant components and surgical techniques and a better understanding of biology around a single implant. Single-tooth implant-replacement is now considered as a reliable and predictable treatment option for a single missing tooth and its application seems to expand to compromised situations which were previously thought to be impossible for single implant therapy.