Comparing the Bioactive Effects of Ethylenediaminetetraacetic Acid and Maleic Acid on TGF-β1 Release From Dentine and Dental Pulp Stem Cell Activity

Aim: The success of vital pulp treatment (VPT) has been linked to the release of growth factors (GFs) from the dentine matrix, which stimulate dental pulp stem cell (DPSC) activities. Ethylenediaminetetraacetic acid (EDTA) is a commonly used chelating agent that induces the release of GFs bound in the dentine matrix. A 7% Maleic acid (MA) solution has been shown to have better smear layer removal capability and less cytotoxicity compared with 17% EDTA. However, no study has evaluated the effect of 7% MA on the release of GFs from circumpulpal dentine and subsequent DPSC behaviour. This study aimed to evaluate the effect of 17% EDTA and 7% MA conditioning of circumpulpal dentine on the release of transforming growth factor-β1 (TGF-β1), as well as the DPSC activities. Methodology: Dentine slices treated with phosphate-buffered saline (PBS) acted as the control, while the experimental groups comprised 17% EDTA and 7% MA. The release of TGF-β1 was quantified using ELISA following treatment with the experimental solutions. DPSC proliferation was evaluated with the MTT assay, cell migration was assessed through scratch wound and transwell migration assays. Osteogenic differentiation potential of DPSCs was verified using Alizarin Red staining and an alkaline phosphatase (AP) activity assay. Results: 7% MA induced the highest release of TGF-β1 compared with 17% EDTA and PBS (p < 0.001). 7% MA at 1/1000 dilution significantly increased DPSC proliferation compared with 17% EDTA and PBS (p < 0.001). The scratch wound healing and transwell migration assays demonstrated superior DPSC migration in the 7% MA compared with the 17% EDTA group (p < 0.001). Alizarin Red staining and quantification indicated the highest formation of mineralized nodules in the 7% MA compared with the 17% EDTA group (p < 0.0001). The AP activity assay showed similar enzyme activity in 7% MA and 17% EDTA treated samples. Conclusions: Within the limitations of this study 7% MA performed better than 17% EDTA in promoting TGF-β1 release from dentine, as well as increased DPSC responses related to cell proliferation, migration, and mineralisation. These findings indicate that 7% MA may be a promising dentine conditioning agent during VPT procedures.