Table 1.

Annual marginal bone loss

Implants	n	Speed ± SD
Failing	8	0.81 ± 0.95 mm per year
Surviving	72	0.12 ± 0.17 mm per year
All	80	0.19 ± 0.39 mm per year

SD, standard deviation.

For testing the rate of bone loss and for comparing failing with surviving implants, one site per patient was taken into consideration. The annual loss was determined as the difference between the first and last bone level divided by the corresponding time interval. Speed was significantly non-zero (p < 0.001). Failing and surviving implants did not differ significantly.