Effect of ethylenediaminetetraacetic acid and hyaluronic acid on the viability and cytokine expression of periodontal ligament fibroblasts

Assessment of the effects of citric acid and EDTA on cell viability of cultured human periodontal ligament cells attached to simulated avulsed permanent tooth using a spectrofluorometer-An in vitro study

BACKGROUND/AIM

The delayed re-implantation of avulsed teeth results in ankylosis, followed by replacement resorption and eventual loss of the tooth within 2-4 years. To prevent tooth loss, the root surface can be etched with acid to expose the collagen fibers present in the cementum layer. This process facilitates normal reattachment and regeneration of the periodontal ligament. This in-vitro study aimed to assess the viability and number of attached cultured Human Periodontal Ligament Cells (HPLC) on the dehydrated root surface of simulated avulsed teeth treated with citric acid and EDTA solutions.

MATERIALS AND METHODS

Sound human permanent teeth were included in the study. The root portions of the teeth were sectioned into slices, air-dried for 1 h, and divided into the following three groups: Group A-control; Group B-Citric acid treated for 30 min; Group C-EDTA treated for 5 min. The slices were then placed in cultured HPLC. After a 24-h incubation period, the slices were visualized under the microscope and prepared for reading the viable and dead HPLC using a spectrofluorometer, as well as for counting HPLC in a Neubauer Chamber.

RESULTS

The spectrofluorometer intensity for viable and dead HPLC showed a statistically significant difference (p = .003 and p = .002), with the mean intensity for viable HPLC greater in citric acid group (69.52 ± 74.51), followed by EDTA group (31.39 ± 9.12), and control group (-130.93 ± 30.99). The dead HPLC intensity was greater in the EDTA group (19.43 ± 47.31), followed by the citric acid group (1.28 ± 1.85), and the control group (-2.77 ± 0.76). The total number of cells in the Neubauer chamber showed a statistically significant difference (p < 0.001), with a higher count in the citric acid group (10.83 ± 4.08) followed by EDTA group (2.92 ± 2.92).

CONCLUSION

The application of citric acid for 30 min on the dehydrated root surface of avulsed teeth demonstrated superior outcomes compared to both EDTA treatment for 5 min and the control group.

Fibroblast Viability Through Mechanical and Chemical Root Surface Modifications in Periodontal Healing: An In Vitro Comparative Study

BACKGROUND

The wound-healing process incorporates a spectrum of periodontal therapeutic interventions that strive to restore the health and function of the periodontium. Fibroblasts play pivotal roles in tissue repair and regeneration. Extensive research has been focused on mechanical and chemical root surface modifications to enhance fibroblast adhesion, which is crucial for successful wound healing.

PURPOSE

This study aimed to assess the combined efficacy of mechanical and chemical root surface modifications in promoting fibroblast viability to root surfaces affected by periodontitis in comparison to chemical modifications alone.

MATERIALS AND METHODS

Root samples were collected from healthy individuals and those with advanced periodontitis. The specimens were prepared, and the experimental groups were categorized based on the type of surface modification with mechanical and/or chemical materials, including hyaluronic acid (HA), ethylenediaminetetraacetic acid (EDTA), enamel matrix derivatives (EMD), and EDTA/EMD. Fibroblasts were seeded onto previously treated root samples. Cell adhesion was assessed using a viability assay.

RESULTS

Fibroblast viability was significantly higher on root surfaces treated with chemical agents than on those treated with mechanical and chemical modifications. Long-duration EDTA and short-duration EMD treatments were significantly effective in enhancing cell viability. EDTA/EMD surface treatments resulted in significantly higher cell viability in all groups compared to the periodontitis root surfaces.

CONCLUSION

EDTA, EMD, and their combined application can potentially ameliorate periodontitis-induced surface structural impairments. Mechanical surface debridement can significantly affect the effectiveness of EDTA and EMD root conditioning agents.

[Periostin inhibits hypoxia-induced oxidative stress and apoptosis in human periodontal ligament fibroblasts via p38 MAPK signaling pathway]

OBJECTIVE

To investigate the effect of periostin on hypoxia-induced oxidative stress and apoptosis in human periodontal ligament fibroblasts and the molecular mechanism involved.

METHODS

In vitro cultured human periodontal ligament fibroblasts were placed in an anaerobic gas-producing bag for hypoxia treatment for 48 h followed by treatment with periostin at low (25 ng/mL), moderate (50 ng/mL) or high (100 ng/mL) doses. MTT assay was used to measure the cell viability, and the cell apoptosis rate was determined using flow cytometry. The contents of IL-1β, IL-6 and TNF-α in the cells were determined with ELISA, and ROS levels were measured using a fluorescent plate reader. The intracellular SOD activity was detected using ELISA. The expressions of HIF-1α, P21, cyclin D1, Bax, cleaved caspase-3, Bcl-2, P38MAPK and p-p38 MAPK proteins in the cells were detected with Western blotting.

RESULTS

Hypoxia treatment significantly reduced the cell viability (P < 0.05), increased P21, Bax, and cleaved caspase-3 protein levels (P < 0.05), promoted cell apoptosis (P < 0.05), and decreased cyclin D1 and Bcl-2 protein levels (P < 0.05) in the cells. Compared with the hypoxic group, the cells treated with periostin at different concentrations showed significantly increased cell viability (P < 0.05) with significantly lowered apoptotic rates (P < 0.05) and decreased expression levels of Bax and cleaved caspase-3 (P < 0.05) but significantly increased expression levels of cyclin D1 and Bcl-2 (P < 0.05). Hypoxic exposure of the cells resulted in significantly increased expression levels of HIF-1α and p-p38 MAPK (P < 0.05) and increased levels of IL-1β, IL-6, TNF-α and ROS (P < 0.05) but decreased SOD activity (P < 0.05). Periostin treatment at different concentrations significantly lowered the expression levels of HIF-1α and p-p38 MAPK (P < 0.05) and the levels of IL-1β, IL-6, TNF-α and ROS (P < 0.05) and significantly increased SOD activity in the hypoxic cells (P < 0.05).

CONCLUSIONS

Periostin promotes the proliferation, inhibits apoptosis, enhances cellular antioxidant capacity, and reduces inflammatory damage in human periodontal ligament fibroblasts exposed to hypoxia possibly by inhibiting the activation of the p38 MAPK signaling pathway.