Table 3 A summary of GCF sampling, method of storing the samples, ELISA kits and laboratory analysis of the included studies

Balli U (2014), [19]

Gingival crevicular fluid was sampled with filter paper using the intracrevicular method

The samples were placed into a sterile polypropylene tube and stored at -70 °C until analysis

ELISA Kit

Commercially available Periostin kit (Uscn Life Science Inc., Wuhan, China)

Jamesha FI (2018), [20]

Microcapillary pipettes

Wrapped in aluminum foil, placed inside separate sterile tubes and stored at − 80 °C in an ultra‑low temperature freezer

ELISA Kit

–

Sophia K (2020), [11]

Microcapillary pipettes

The GCF and serum samples were stored at -70 °C until the time of assay

ELISA Kit

–

Radhika BN (2019), [22]

Microcapillary pipette

Eppendorf tube and stored at –80 °C in a deep freezer, until further processing

ELISA Kit

Bioassay Technology Laboratory, 1713, Junjiang International Bldg, Yangpu Dist, Shanghai, China

Momeni F (2020), [21]

Paper strips

Store in buffer solution tube at -20 c

ELISA Kit

–

Rezaei B (2021), [23]

Paper strips

Placed into microcentrifuge tubes and stored at − 20 °C

ELISA Kit

–

Akman AC (2018), [18]

Standardized paper strips were inserted 1 mm depth

GCF samples were placed in sterile Eppendorf tubes and carefully wrapped to be stored in -80 °C

ELISA Kit

Human periostin ELISA kit Periostin (CSB-E16444h) Cusabio, Wuhan, China

Sari A (2022), [24]

The samples were collected within 30 s with standardized paper strips (Periopaper; Orafow Inc., Plainview, NY) by the orifce method

Periopaper strips were pooled in plastic Eppendorf microcentrifuge tubes and stored at – 80 °C

ELISA Kit

Elabscience, catalog no: E-EL-H6113