TABLE 6.

Univariate Cox proportional hazard models for single crown failure

Factor	Hazard ratio (95% CI)	p value
Sex
Male	1
Female	0.88 (0.68, 1.14)	0.33
Age
<50 years	1
≥50 years	0.94 (0.72, 1.23)	0.65
Jaw
Maxilla	1
Mandible	0.67 (0.51, 0.88)	0.004
Crown region
Anterior	1
Posterior	0.66 (0.50, 0.88)	0.004
Tooth type
Incisor	1
Canine	0.94 (0.52, 1.69)	0.84
Premolar	0.66 (0.47, 0.93)	0.017
Molar	0.65 (0.46, 0.91)	0.013
Tooth vitality
Non‐vital	1
Vital	0.61 (0.47, 0.80)	<0.001
Post and core a
No	1
Yes	0.82 (0.50, 1.35)	0.44
Material
All‐ceramic	1
Gold ceramic	0.75 (0.49, 1.14)	0.17
Full gold	0.71 (0.37, 1.37)	0.31
CoCr ceramic	1.11 (0.61, 2.01)	0.73
Crown occluding to
Natural teeth	1
Fixed prosthesis	1.19 (0.91, 1.55)	0.21
Treatment provider
Dental student	1
General or specialist dentist	0.89 (0.61, 1.29)	0.53
Bruxism
No	1
Yes	1.55 (1.88, 2.02)	0.001
Smoking
No	1
Yes	1.37 (0.94, 1.99)	0.10
Ex‐smoker	0.85 (0.50, 1.46)	0.56

Abbreviation: 95% CI, 95% confidence interval.

^a Only for non‐vital teeth.