Cellular viability and genetic expression of human gingival fibroblasts to zirconia with enamel matrix derivative (Emdogain®)

PURPOSE. The objective of this study was to investigate the biologic effects of enamel matrix derivative (EMD) with different concentrations on cell viability and the genetic expression of human gingival fibroblasts (HGF) to zirconia surfaces. MATERIALS AND METHODS. Immortalized human gingival fibroblasts (HGF) were cultured (1) without EMD, (2) with EMD 25 μg/mL, and (3) with EMD 100 μg/mL on zirconia discs. MTT assay was performed to evaluate the cell proliferation activity and SEM was carried out to examine the cellular morphology and attachment. The mRNA expression of collagen type I, osteopontin, fibronectin, and TGF-ß1 was evaluated with the real-time polymerase chain reaction (RT-PCR). RESULTS. From MTT assay, HGF showed more proliferation in EMD 25 μg/mL group than control and EMD 100 μg/mL group (P<.05). HGFs showed more flattened cellular morphology on the experimental groups than on the control group after 4h culture and more cellular attachments were observed on EMD 25 μg/mL group and EMD 100 μg/mL group after 24h culture. After 48h of culture, cellular attachment was similar in all groups. The mRNA expression of type I collagen increased in a concentration dependent manner. The genetic expression of osteopontin, fibronectin, and TGF-ß1 was increased at EMD 100 μg/mL. However, the mRNA expression of proteins associated with cellular attachment was decreased at EMD 25 μg/mL. CONCLUSION. Through this short term culture of HGF on zirconium discs, we conclude that EMD affects the proliferation, attachment, and cell morphology of HGF cells. Also, EMD stimulates production of extracellular matrix collagen, osteopontin, and TGF-ß1 in high concentration levels. Clinical Relevance. With the use of EMD, protective barrier between attached gingiva and transmucosal zirconia abutment may be enhanced leading to final esthetic results with implants.