[Retracted] Effects of Periodontal Treatment on Levels of Proinflammatory Cytokines in Patients with Chronic Periodontitis: A Meta-Analysis

Table 1

Baseline characteristics of the included studies.

No.	First author	Year	Sample time (year.month)	Diagnostic method	No. of patients treat/con	Age (years)	Sex ratio (male/female)	Study design	Outcome measured
									Gingival crevicular fluid	Serum
1	Yu Qin	2018	2015.6~2017.10	ELISA	40/25		23/17	Retrospective	IL-6; TNF-α	NR
2	Jia Ning	2020	2018.1~2018.12	ELISA	64/64		39/25	Retrospective	IL-6; TNF-α	IL-6; TNF-α
3	Yuan Dan	2016	2014.1~2015.3	ELISA	43/43		26/17	Retrospective	IL-6; TNF-α	NR
4	Chang Chunrong	2013	2007.7~2008.10	ELISA	40/50	NR	NR	Retrospective	IL-6; TNF-α	NR
5	Zhang Junqi	2018	2015.1~2017.12	ELISA	50/50		32/18	Retrospective	IL-6; IL-8; TNF-α	IL-6; IL-8; TNF-α
6	Li Ming	2014	2011.1~2013.2	ELISA	40/40		18/22	Retrospective	IL-6	NR
7	Wu Liuzhong	2014	2012.2~2013.9	ELISA	72/72	23~67	38/34	Retrospective	IL-6; TNF-α	NR
8	Liu Haitao	2018	2015.8~2016.12	ELISA	36/36		19/17	Retrospective	IL-6; IL-8	IL-6; IL-8
9	Yu Jiangbo	2013	2012.1~2012.6	ELISA	32/0	45~65	15/17	Retrospective	IL-6; TNF-α	NR
10	Huang Haixia	2018	2015.9~2017.9	ELISA	46/43		24/19	Retrospective	IL-6; IL-8; TNF-α	IL-6; IL-8; TNF-α
11	Wu Di	2017	2013.10~2015.11	ELISA	67/67		37/30	Retrospective	NR	IL-6; TNF-α
12	Niu Jiahui	2018	2016.8~2017.7	ELISA	60/60		33/27	Retrospective	NR	IL-6; IL-8; TNF-α
13	Li Feng	2018	2016.1~2017.1	ELISA	40/40		25/15	Retrospective	NR	IL-8; TNF-α

Note: NR: not reported; Treat: treatment; Con: control.