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

Table 3

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

Variables	FTB control ()	Nested control ()	PTB ()	value (FTB control)	value (nested control)
PD (mm)				0.98	0.76
(%)	5.66; (0.67 to 16.07)	4.49; (0.94 to 10.21)	11.31; (3.21 to 17.26)	0.47	0.28
BI	1.95; (1.42 to 2.68)	1.83; (1.51 to 2.56)	1.77; (1.38 to 2.64)	0.83	0.86
TNF-α (pg/ml)				0.40	0.64
IL-1β (pg/ml)				0.81	0.78
PGE2 (pg/ml)				0.77	0.90
IL-6 (pg/ml)				0.28	0.51
8-OHdG (pg/ml)				0.84	0.77

. 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.