Kyushikai Association promotes tooth transplantation for the replacement of lost teeth in adults. The policy of this group is to save and utilize patients¿ natural teeth as much as possible. Our consensus is that maintaining occlusal support is very important for the prevention of future tooth loss. Tooth loss increases after middle age; therefore, most cases of transplantation in our group use donor teeth with complete root formation, and the age of most patients is high. The purpose of tooth transplantation in these cases is a little different from that of other associations that primarily use donor teeth with incomplete roots. As in any country, there is economic disparity among our patients here in Japan. Since tooth transplantation is an inexpensive procedure, we believe it will become more common even with donor teeth with developed roots. In this book, we introduce our research on transplanted teeth with complete root formation. We hope our methods, findings, and discussions will be useful for patients and dental practitioners.