Abstract
The Periotest® values (PTVs) of 11 single free standing implants for a long period were measured.
In the 4 cases (A, B, C, D) of Brånemark system® , the PTVs of 2 cases (A, B) were about zero after a long period. The other PTVs of 2 cases (C, D) rapidly tended upwards for a half year, and since then tended downwards slowly. In the 4 cases (E, F, G, H) of ITI bonefit® , the PTVs of 2 cases (E, F) tended downwards for a long period and were about zero after g yrs. The PTV of case (G) was 1.0 immediately after the setting of the superstructure and -2.0 after 5 yrs.10 mos., but 6.4 after 9 yrs. 2 mos. because the screw loosing of the abutment and the implant body. The PTV was -2.8 after tightening the screw. The PTV of case (H) increased from 7.2 to 11.6 for l mo., and since then tended downwards gradually. In the 3 cases (I, J, K) of ITI Ftype, the PTV of case (I) tended upwards on the way, and was 3.4 after 12 yrs.11 mos. The PTVs of case (J) tended downwards slowly since starting of PTV measurement. The PTVs of case (K) were over 13.6 for 7 yrs. 2 mos. without unusual xray finding.
As mentioned above, the PTVs of single free standing implant changed variously for a long period. The prognoses of implants ought to be decided synthotically with PTV, intra-oral and x-ray examination.
