title: Release of Growth Factors into Root Canal by Irrigations in Regenerative Endodontics.
abstract: BACKGROUND
  The aim of this study was to investigate the release of growth factors into root canal space after the irrigation procedure of regenerative endodontic procedure.
  
  
  METHODS
  Sixty standardized root segments were prepared from extracted single-root teeth. Nail varnish was applied to all surfaces except the root canal surface. Root segments were irrigated with 1.5% NaOCl + 17% EDTA, 2.5% NaOCl + 17% EDTA, 17% EDTA, or deionized water. The profile of growth factors that were released after irrigation was studied by growth factor array. Enzyme-linked immunosorbent assay was used to validate the release of transforming growth factor (TGF)-β1 and basic fibroblast growth factor (bFGF) at 4 hours, 1 day, and 3 days after irrigation. The final concentrations were calculated on the basis of the root canal volume measured by cone-beam computed tomography. Dental pulp stem cell migration on growth factors released from root segments was measured by using Transwell assay.
  
  
  RESULTS
  Total of 11 of 41 growth factors were detected by growth factors array. Enzyme-linked immunosorbent assay showed that TGF-β1 was released in all irrigation groups. Compared with the group with 17% EDTA (6.92 ± 4.49 ng/mL), the groups with 1.5% NaOCl + 17% EDTA and 2.5% NaOCl + 17% EDTA had significantly higher release of TGF-β1 (69.04 ± 30.41 ng/mL and 59.26 ± 3.37 ng/mL, respectively), with a peak release at day 1. The release of bFGF was detected at a low level in all groups (0 ng/mL to 0.43 ± 0.22 ng/mL). Migration assay showed the growth factors released from root segments induced dental pulp stem cell migration.
  
  
  CONCLUSIONS
  The root segment model in present study simulated clinical scenario and indicated that the current irrigation protocol released a significant amount of TGF-β1 but not bFGF. The growth factors released into root canal space induced dental pulp stem cell migration.
authors.affiliation: Operative Dentistry and Endodontics, Guanghua School of Stomatology, Affiliated Stomatological Hospital, Guangdong Province Key Laboratory of Stomatology, Sun Yat-Sen University, Guangzhou, Guangdong, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zeng
authors.affiliation: Department of Endodontology, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania.
authors.forename: Sean
authors.initials: S
authors.lastname: Nguyen
authors.affiliation: Department of Endodontology, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania.
authors.forename: Hongming
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Endodontology, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania.
authors.forename: Hari Priya
authors.initials: HP
authors.lastname: Chebrolu
authors.affiliation: Regenerative Health Laboratory, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania.
authors.forename: Dalia
authors.initials: D
authors.lastname: Alzebdeh
authors.affiliation: Division of Oral and Maxillofacial Radiology, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania.
authors.forename: Mustafa A
authors.initials: MA
authors.lastname: Badi
authors.affiliation: Department of Endodontology, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania.
authors.forename: Jong Ryul
authors.initials: JR
authors.lastname: Kim
authors.affiliation: Guanghua School of Stomatology, Affiliated Stomatological Hospital, Guangdong Province Key Laboratory of Stomatology, Sun Yat-Sen University, Guangzhou, Guangdong, China. Electronic address: lingjq@mail.sysu.edu.cn.
authors.forename: Junqi
authors.initials: J
authors.lastname: Ling
authors.affiliation: Department of Endodontology, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania. Electronic address: myang@temple.edu.
authors.forename: Maobin
authors.initials: M
authors.lastname: Yang
mesh_terms: D002465:Cell Movement / Q000187:drug effects; D054893:Cone-Beam Computed Tomography; D003782:Dental Pulp / Q000166:cytology; D003786:Dental Pulp Cavity / Q000187:drug effects*; D004492:Edetic Acid / Q000627:therapeutic use; D004708:Endodontics / Q000379:methods*; D004797:Enzyme-Linked Immunosorbent Assay; D016222:Fibroblast Growth Factor 2 / Q000032:analysis / Q000187:drug effects; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000032:analysis*; D012038:Regeneration / Q000187:drug effects*; D012388:Root Canal Irrigants / Q000627:therapeutic use*; D018915:Root Canal Preparation / Q000379:methods; D012390:Root Canal Therapy / Q000379:methods*; D012973:Sodium Hypochlorite / Q000627:therapeutic use; D013234:Stem Cells; D019227:Tooth Apex / Q000187:drug effects; D014092:Tooth Root / Q000187:drug effects; D053773:Transforming Growth Factor beta1 / Q000032:analysis / Q000187:drug effects
chemical_list: D036341:Intercellular Signaling Peptides and Proteins; D012388:Root Canal Irrigants; D053773:Transforming Growth Factor beta1; D016222:Fibroblast Growth Factor 2; D004492:Edetic Acid; D012973:Sodium Hypochlorite
keywords: Cell migration; growth factors; irrigation; regenerative endodontics; root canal surface