[A long-term retrospective clinical study of short dental implant restoration]

To evaluate the long-term results of short implants and assess its clinical importance.

A total of 77 short implants were consecutively placed in 43 patients from August 1998 to August 2004. The clinical data was reviewed and the crown-implant ratio (C/I) was measured. Twenty-nine short implants in 15 patients were loaded for more than 5 years and the marginal bone height around implant measured. The implant success and survival ratio were evaluzted according to Zarb's successful criteria and Wheeler's survival criteria.

The mean follow-up time was 5.4 years (36 ∼ 99 months). Among these 77 short implants, 74 implants were fixed restoration, which mean C/I was (1.08 ± 0.21), 3 implants were removable restoration. Of 29 short implants which were loaded for more than 5 years, the mesial bone height at the times immediately after inserting implant, before second stage surgery, loading for less than 3 years and loading for more than 5 years was (0.59 ± 0.66), (0.64 ± 0.59), (-0.05 ± 1.11), (-0.37 ± 1.29) mm; and the distal bone height was (0.62 ± 0.77), (0.60 ± 0.86), (-0.26 ± 1.12), (-0.23 ± 1.59) mm. The 5 year's survival rate and success rate were 97% and 93% respectively.

The success and survival rate of short dental implant under function were comparable to those reported for normal implants. By using the short implant, the patients can avoid the graft operation, alleviate sufferings, shorten the treatment period and reduce the cost. Therefore, it has a high value in clinical application.