A Nested Case-Control Study of the Relationship between Salivary Inflammatory Mediators, Periodontal Parameters, and Preterm Birth in a Chinese Population

Table 4

Periodontal indexes and PGE2, IL-1β, IL-6, TNF-α, and 8-OHdG salivary levels in PTB and FTB in group C.

Variables	FTB control ()	Nested control ()	PTB ()	value (FTB control)	value (nested control)
PD (mm)				0.09	0.02
(%)	4.17; (1.20 to 14.51)	4.17; (1.51 to 12.80)	13.10; (3.89 to 28.23)	0.09	0.04
BI	1.58; (1.25 to 2.10)	1.54; (1.24 to 1.91)	2.75; (1.97 to 3.07)	0.004	0.001
TNF-α (pg/ml)				0.045	0.01
IL-1β (pg/ml)				0.86	0.84
PGE2 (pg/ml)				0.03	0.01
IL-6 (pg/ml)				0.25	0.27
8-OHdG (pg/ml)				0.30	0.09

. BI: bleeding index; FTB: full term birth; PTB: preterm birth; IL-1β: interleukin-1β; IL-6: interleukin-6; 8-OHdG: 8-hydroxy-deoxyguanosine; PD: probing depth; PGE2: prostaglandin E2; TNF-α: tumor necrosis factor-α.