Table 2.

Complications in dependence of the residual height of the alveolar ridge

	Residual height, binary		p-value
	< 3 mm [n = 63]	≥ 3 mm [n = 40]
Is the implant still in situ?
Yes [n = 100]	62	38	0.558
No [n = 3]	1	2
Bleeding-on-probing
No [n = 35]	17	18	0.087
Yes [n = 68]	46	22
Probing depth (mm)
0 mm [n = 68]	41	27	0.645
4 mm [n = 9]	5	4
5 mm [n = 12]	7	5
6 mm [n = 12]	9	3
8 mm [n = 1]	1	0
12 mm [n = 1]	0	1
Peri-implantitis
No [n = 88]	54	34	0.999
Yes [n = 15]	9	6
Mucositis
No [n = 19]	11	8	0.797
Yes [n = 84]	52	32
Membrane perforation
No [n = 67]	47	20	0.019
Yes [n = 36]	16	20

P-values were obtained from Chi-squared tests