Methods: In this study we have established an ovine periodontal defect model to examine the regenerative potential of PDLSC implants. Critical-sized periodontal defects were surgically created on the exposed buccal plate of alveolar bone covering the mandibular first molar on both the left and right sides of 9 merino sheep. Autologous PDLSCs were seeded onto various biocompatible scaffolds, implanted into defects and then covered by the mucoperiosteal flap. Control defects in the same animals were implanted with scaffold alone. Animals were sacrificed at eight weeks post implantation and mandible alveolar bone blocks containing defects were excised. These blocks were fixed, analysed by CT microscopy and then processed for histological examination.
Results: The experimental animals showed excellent recovery and tolerance to the implants. Preliminary CT microscopy and histological analysis demonstrated that a cementum-like tissue had regenerated in the defects implanted with PDLSCs attached to HA/TCP scaffold which was not evident in the HA/TCP scaffold alone control in 2 sheep. Surviving implanted PDLSCs were also identified within the regenerated tissue. Once specimens from all 9 sheep have been processed for analysis, we anticipate the findings will determine which biocompatible scaffold is most suitable for use in future PDLSC-based periodontal tissue regeneration studies.
Conclusion: The present pre-clinical model can be used to further our understanding of PDLSCs in tissue engineering and establish more predictable regeneration of periodontal tissues as a prelude to human clinical trials.