Loss of Dental Implants and Factors Associated with the Outcome

Objectives:

To assess the outcome of different dental implants inserted at the Institute of Clinical Odontology, University of Oslo between 1990 and 2005. Implant loss is the outcome variable associated to factors regarding the patients.

Methods:

164 patients having had fixtures inserted and supra-structures made at the institute during these years were invited to join the study. Four of the patients were deceased, 4 have unknown addresses, 13 did not reply, and 30 did not want to or were unable to attend, leaving 104 patients available for examination. The examination consisted of radiographic and clinical evaluation and questionnaire regarding general health and quality of life.

Results:

104 patients treated with 318 implants were examined. Fourteen implants have been lost in 9 patients. Three patients lost 2 and 1 patient lost 3. Two implants were categorized as “sleeping implants” and never loaded.

The implants were categorized into 4 groups: Lost before loading, lost 0-5 years after loading, lost 5-10 years and lost after more than 10 years. Eight of the implants (2.5%) were lost within the first year after insertion and before loading, 3 were lost during the first 5 years after loading and 3 were lost 5 to 10 years after loading.

Nine implants were reported lost due to lack of osseointegration, 3 due to peri-implantitis and 2 losses were caused by fracture of the fixture.

Two of the 4 diabetic patients in the population (50%) experienced implant loss, 7 of the 95 non-diabetics (7.4%) experienced loss. The corresponding numbers for cardiac disease were 4/16 (25%) vs. 5/83 (6.0%) and for current/former smokers vs. non-smokers, the numbers were 8/55 (14.5%) vs. 1/44 (2.3%)

Conclusion:

Implant treatment has a high survival-rate, especially after the first year of insertion. Later implant loss seems to be associated with certain health and habitual factors.