title: A histological and micro-CT investigation in to the effect of NGF and EGF on the periodontal, alveolar bone, root and pulpal healing of replanted molars in a rat model - a pilot study.
abstract: BACKGROUND
  This study aims to investigate, utilising micro-computed tomography (micro-CT) and histology, whether the topical application of nerve growth factor (NGF) and/or epidermal growth factor (EGF) can enhance periodontal, alveolar bone, root and pulpal tissue regeneration while minimising the risk of pulpal necrosis, root resorption and ankylosis of replanted molars in a rat model.
  
  
  METHODS
  Twelve four-week-old male Sprague-Dawley rats were divided into four groups: sham, collagen, EGF and NGF. The maxillary right first molar was elevated and replanted with or without a collagen membrane impregnated with either the growth factors EGF or NGF, or a saline solution. Four weeks after replantation, the animals were sacrificed and the posterior maxilla was assessed using histological and micro-CT analysis. The maxillary left first molar served as the control for the corresponding right first molar.
  
  
  RESULTS
  Micro-CT analysis revealed a tendency for all replanted molars to have reduced root length, root volume, alveolar bone height and inter-radicular alveolar bone volume. It appears that the use of the collagen membrane had a negative effect while no positive effect was noted with the incorporation of EGF or NGF. Histologically, the incorporation of the collagen membrane was found to negatively affect pulpal, root, periodontal and alveolar bone healing with pulpal inflammation and hard tissue formation, extensive root resorption and alveolar bone fragmentation. The incorporation of EGF and NGF did not improve root, periodontal or alveolar bone healing. However, EGF was found to improve pulp vascularisation while NGF-improved pulpal architecture and cell organisation, although not to the level of the control group.
  
  
  CONCLUSIONS
  Results indicate a possible benefit on pulpal vascularisation and pulpal cell organisation following the incorporation of EGF and NGF, respectively, into the alveolar socket of replanted molars in the rat model. No potential benefit of EGF and NGF was detected in periodontal or root healing, while the use of a collagen membrane carrier was found to have a negative effect on the healing response.
authors.affiliation: Department of Orthodontics, The University of Western Australia, Crawley, Western Australia 6009, Australia. frank.furfaro@uwa.edu.au.
authors.forename: Francesco
authors.initials: F
authors.lastname: Furfaro
authors.forename: Estabelle S M
authors.initials: ES
authors.lastname: Ang
authors.forename: Ricky R
authors.initials: RR
authors.lastname: Lareu
authors.forename: Kevin
authors.initials: K
authors.lastname: Murray
authors.forename: Mithran
authors.initials: M
authors.lastname: Goonewardene
mesh_terms: D000539:Alveolar Process / Q000187:drug effects* / Q000473:pathology; D000818:Animals; D003094:Collagen; D003782:Dental Pulp / Q000098:blood supply / Q000187:drug effects* / Q000473:pathology; D003790:Dental Pulp Necrosis / Q000517:prevention & control; D004195:Disease Models, Animal; D004815:Epidermal Growth Factor / Q000627:therapeutic use*; D008297:Male; D008437:Maxilla / Q000187:drug effects / Q000473:pathology; D008567:Membranes, Artificial; D008963:Molar / Q000187:drug effects* / Q000473:pathology; D018919:Neovascularization, Physiologic / Q000187:drug effects; D020932:Nerve Growth Factor / Q000627:therapeutic use*; D010519:Periodontium / Q000187:drug effects* / Q000473:pathology; D011671:Pulpitis / Q000209:etiology; D011897:Random Allocation; D017207:Rats, Sprague-Dawley; D012038:Regeneration / Q000187:drug effects; D012391:Root Resorption / Q000517:prevention & control; D020254:Tooth Ankylosis / Q000517:prevention & control; D014090:Tooth Replantation / Q000379:methods*; D014092:Tooth Root / Q000187:drug effects* / Q000473:pathology; D014945:Wound Healing / Q000187:drug effects; D055114:X-Ray Microtomography / Q000379:methods
chemical_list: D008567:Membranes, Artificial; D004815:Epidermal Growth Factor; D003094:Collagen; D020932:Nerve Growth Factor