title: Effects of enamel matrix proteins on tissue formation along the roots of human teeth.
abstract: OBJECTIVE
  Enamel matrix-derived proteins (EMD) are thought to trigger the formation of acellular extrinsic fibre cementum (AEFC), while other reports indicate that EMD may have osteogenic potential. The aim of the present study was to characterize the tissues developing on the root surface following application of EMD.
  
  
  METHODS
  Twelve human periodontitis-affected teeth, scheduled for extraction, were treated with EMD. Two to 6 weeks later, the teeth were extracted, demineralized and processed for embedding in acrylic and epoxy resins. New tissue formation was analysed by light and transmission electron microscopy.
  
  
  RESULTS
  New tissue formation on the root was observed in the notch and on both scaled and unscaled root surfaces distant of the notch area in six defects. The newly formed tissues on the root were thick, collagenous, devoid of extrinsic fibres, and had an irregular surface contour. The presence of electron-dense, organic material in the collagenous matrix indicated at least partial mineralization. Embedded cells were numerous and the cells on the matrix surface were very large in size. Abundant rough endoplasmic reticulum and a prominent Golgi complex were evident. The presence of a split between the treated root surfaces and the newly formed tissue was a common observation, as was the presence of bacteria and host cells in the interfacial gap.
  
  
  CONCLUSIONS
  Following treatment with EMD, a bone-like tissue resembling cellular intrinsic fibre cementum may develop on the root surfaces, instead of AEFC. Furthermore, EMD may both induce de novo formation of a mineralized connective tissue on scaled root surfaces and stimulate matrix deposition on old native cementum. Interfacial bonding appeared to be weak after 6 weeks of healing.
authors.affiliation: Department of Periodontology and Fixed Prosthodontics, School of Dental Medicine, University of Berne, Berne, Switzerland. dieter.bosshardt@zmk.unibe.ch
authors.forename: Dieter D
authors.initials: DD
authors.lastname: Bosshardt
authors.forename: Anton
authors.initials: A
authors.lastname: Sculean
authors.forename: Péter
authors.initials: P
authors.lastname: Windisch
authors.forename: Bjarni E
authors.initials: BE
authors.lastname: Pjetursson
authors.forename: Niklaus P
authors.initials: NP
authors.lastname: Lang
mesh_terms: D025021:Cementogenesis / Q000502:physiology*; D003739:Dental Cementum / Q000187:drug effects; D003746:Dental Enamel Proteins / Q000627:therapeutic use*; D005260:Female; D048091:Guided Tissue Regeneration / Q000379:methods*; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D010518:Periodontitis / Q000628:therapy; D014092:Tooth Root / Q000187:drug effects* / Q000502:physiology / Q000648:ultrastructure
chemical_list: D003746:Dental Enamel Proteins; C109069:enamel matrix proteins