Human periodontal ligament fibroblast response to PDGF-BB and IGF-1 application on tetracycline HCI conditioned root surfaces

. The purpose of this study was to investigate the effect of 2 growth factors, platelet‐derived growth factor‐BB (PDGF‐BB) and insulin‐like growth factor‐1 (IGF‐1) alone or in combination, on the adherence of human periodontal ligament fibroblast (PDL) to tetracycline HCI (TTC) conditioned and non‐conditioned periodontally involved root surfaces. There were 80 root dentine chips from 80 patients, ranging from 35 to 70 years of age, each with one periodontally involved tooth requiring extraction. A root dentine chip was obtained from the subgingival surface opposite to the periodontal pocket of each extracted tooth. The dentine chips were randomly distributed into one of 8 groups. In group 1, PDL Fibroblasts were cultured and allowed to attach on the dentine surface. In group 2, PDL fibroblasts were cultured on a PDGF‐BB pre‐treated dentine surface and in group 3, they were cultured on a IGF‐1 pre‐treated dentine surface. In group 4, PDL fibroblasts were cultured on a dentine surface pretreated with a combination of PDGF‐BB and IGF‐1. In group 5, PDL fibroblasts were cultured and allowed to attach on the TTC conditioned dentine surfaces. In groups 6 and 7, surface of dentine chips were conditioned with TTC and then were treated with PDGF‐BB or IGF‐1 respectively, followed by placement of PDL fibroblast and cultured. In group 8, dentine surfaces were conditioned with TTC and then pre‐treated with a combination of PDGF‐BB and IGF‐1 before the fibroblasts were cultured. After 24 h of incubation, the media was removed and samples were fixed and processed for SEM at magnifications of ×34, ×750, ×2000. Photographing and evaluation of samples was performed at ×750 in which fibroblast adherence was measured by counting cells within a standard test area. The results of the non‐TTC conditioned root surfaces demonstrated a significant increase in fibroblasts adherence in the PDGF‐BB and combination PDGF‐BB/IGF‐1 treatment groups (groups 2, 4) when compared to the control (group 1) as well as the TTC control (group 5). The combination of PDGF‐BB/IGF‐1 (group 4) did not significantly improve the adhesion of cells compared to PDGF‐BB alone (group 2), but did significantly improve adhesion when compared to IGF‐1 alone (group 3). There were no significant differences in cell morphology between the growth factor groups (groups 2, 3, 4) and control (group 1). In general, the cells demonstrated a fiat, stellate‐shaped morphology. The results of the TTC conditioned root surfac