Table 2.

Visual grading of the bone structure relating to the distance from the metallic surface

Visual grading	2 mm		5 mm		10 mm		15 mm
	n	%	n	%	n	%	n	%
G0	1652	51.2	974	29.8	720	22.0	720	29.1
G1	924	28.6	730	22.4	212	6.4	44	1.8
G2	492	15.2	1108	33.9	966	29.5	188	7.6
G3	160	5.0	452	13.9	1378	42.1	1520	61.5
Total	3228	100.0	3264	100.0	3276	100.0	2472	100.0

n, total number of observations (two observations for each of the three operators).