Immunohistochemical investigation on the pattern of vimentin expression in regenerated and intact monkey and human periodontal ligament

The expression of vimentin is well documented in the intact animal and human periodontal ligament (PDL), but there is limited information on the pattern of vimentin expression in the regenerated PDL. The aim of the present study was to investigate the pattern of vimentin expression in the regenerated and intact monkey and human PDL. A total of 12 chronic recession-type defects were created in three monkeys (Macaca fascicularis) and treated either with guided tissue regeneration (GTR), or with an enamel matrix protein derivative (EMD). After 5 months, the animals were sacrificed and specimens containing the defects and surrounding tissues were dissected free, decalcified in EDTA and embedded in paraffin. Sections were (abetted immunohistochemically by using monoclonal antibody against vimentin (VIM 3134). Twelve patients, each of whom displayed one deep intrabony defect scheduled for extraction were treated with GTR, EMD or combination of EMD + natural bone mineral. (NBM). Following a heating period of 6 months, the teeth were extracted en block and immunohistochemically analysed according to the same protocol. as described in monkeys. The results revealed that in both monkeys and humans the newly formed PDL was labelled similarly for vimentin to the intact (non-treated) PDL. In all specimens, the newly formed PDL was in continuation with the intact parts of PDL, thus suggesting that the mesenchymal cells capable of regenerating the attachment apparatus may have their origin in the intact PDL. In conclusion, the present findings indicate that (a) the reformed PDL displayed a similar expression of vimentin to the intact (original) PDL, and (b) the cells capable of regenerating new PDL and new cementum appear to be of mesenchymal origin and their source may be in the intact PDL. (C) 2003 Elsevier Science Ltd. All rights reserved.