Table 1.

Characteristics of patients and involved restorations and p-values of the univariate analysis by log-rank tests (categorial variables)

	Number of restorations		% of restorations		p value
	Total (N = 728)	Failed (N = 116)	Total (N = 728)	Failed (N = 116)
Type of disability					< 0.001
Intellectual (n = 41)	339	27	46.6	23.3
Physical (n = 7)	79	30	10.9	25.9
Both intellectual and physical (n = 53)	310	59	42.6	50.9
Gender					n.s.
Male (n = 51)	398	80	54.7	69.0
Female (n = 50)	330	36	45.3	31.0
Living situation					n.s.
Care facility (n = 52)	325	53	44.6	45.7
Private setting (with family or alone, n = 46)	380	60	52.2	51.7
Unknown (n = 3)	23	3	3.2	2.6
Oral hygiene					n.s.
Alone (n = 37)	282	42	38.7	36.2
With support (n = 48)	333	57	45.7	49.1
Impossible (n = 12)	76	10	10.4	8.6
Unknown (n = 4)	37	7	5.1	6.0
Nutrition					< 0.001
Without restrictions (n = 72)	517	57	71.0	49.1
Pureed/liquid food (n = 17)	120	32	16.5	27.6
Feeding tube (n = 9)	56	20	7.7	17.2
Unknown (n = 3)	35	7	4.8	6.0
Removable partial denture					< 0.001
Yes (n = 17)	141	44	19.4	37.9
No (n = 84)	587	72	80.6	62.1
Postoperative checkup within 3 months					0.038
Yes	278	13	38.2	11.2
No	450	103	61.8	88.8
Number of surfaces of the restoration					n.s.
1	365	54	50.1	46.6
2	201	25	27.6	21.6
≥ 3	162	37	22.3	31.9
Tooth type					< 0.001
Anterior	257	58	35.3	50.0
Premolar	181	21	24.9	18.1
Molar	290	37	39.8	31.9
Load-bearing restorationa					< 0.001
Yes	426	56	58.5	48.3
No	302	60	41.5	51.7
Location					n.s.
Upper jaw	410	74	56.3	63.8
Lower jaw	318	42	43.7	36.2

Due to the effect of rounding, some numbers do not sum up to 100%

n number of patients, n.s. not significant

^aRestorations including occlusal or incisal surfaces