title: Cellular viability and genetic expression of human gingival fibroblasts to zirconia with enamel matrix derivative (Emdogain®).
abstract: OBJECTIVE
  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.
  
  
  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-β1 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-β1 was increased at EMD 100 µg/mL. However, the mRNA expression of proteins associated with cellular attachment was decreased at EMD 25 µg/mL.
  
  
  CONCLUSIONS
  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-β1 in high concentration levels.
  
  
  CONCLUSIONS
  With the use of EMD, protective barrier between attached gingiva and transmucosal zirconia abutment may be enhanced leading to final esthetic results with implants.
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Kyung Hee University, Seoul, Republic of Korea.
authors.forename: Yong-Dae
authors.initials: YD
authors.lastname: Kwon
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Kyung Hee University, Seoul, Republic of Korea.
authors.forename: Hyun-Jung
authors.initials: HJ
authors.lastname: Choi
authors.affiliation: Department of Oral Anatomy, Dental School, Kangnung-Wonju National University, Kangnung, Republic of Korea.
authors.forename: Heesu
authors.initials: H
authors.lastname: Lee
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Kyung Hee University, Seoul, Republic of Korea.
authors.forename: Jung-Woo
authors.initials: JW
authors.lastname: Lee
authors.affiliation: Department of Prosthodontics and Operative Dentistry, Tufts University School of Dental Medicine, Boston, MA, USA.
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Weber
authors.affiliation: Department of Prosthodontics, School of Dentistry, Kyung Hee University, Seoul, Republic of Korea.
authors.forename: Ahran
authors.initials: A
authors.lastname: Pae
keywords: Cell attachment; Cell proliferation; Enamel matrix derivative (Emdogain®); Human gingival fibroblast; Zirconia