Enamel matrix derivative Emdogain® as an adjuvant for a laterally-positioned flap in the treatment of gingival recession: An electron microscopic appraisal

Enamel matrix derivative (EMD), such as Emdogain®, has been suggested for the improvement of wound healing in periodontal surgical therapy. The present qualitative study seeks to illustrate the ultrastructural changes associated with a human gingival wound at 10 days after the application of EMD as an adjunct to a laterally-positioned flap in a patient with gingival recession. An otherwise healthy patient, who had been suffering from bilateral gingival recession defects on teeth #23 and #26, was studied. One defect was treated with a laterally-positioned flap, while the other was treated with a combination of EMD and a laterally-positioned flap. Ten days after the operation gingival biopsy specimens were obtained from the dentogingival region and examined using a transmission electron microscope. A considerable difference was found in both the cellular and extracellular phases of EMD and non-EMD sites. The fibroblasts of EMD site were more rounded with plump cytoplasms and euchromatic nuclei. A well-developed rough endoplasmic reticulum and numerous mitochondria could be detected. In contrast, the fibroblasts of non-EMD site were of flattened spindle-like morphology. While the signs of apoptosis could rarely be detected at EMD site, apoptotic bodies and ultra-structural evidence of apoptosis (crescent-like heterochromatic nuclei and dilated nuclear envelopes) were consistent features at non-EMD site. The extracellular matrix at EMD site mainly consisted of well-organised collagen fibres, while non-EMD site contained sparse and incompletely-formed collagen fibres. Coccoid bacteria were noted within the extracellular matrix and neutrophils at non-EMD site. It seems that EMD may enhance certain features of gingival wound healing, which may be attributable to its anti-apoptotic, anti-bacterial or anti-inflammatory properties.