Purpose: To provide a better understanding of basic molecular and cellular biologic concepts when using membrane barriers and bone grafts in periapical surgery with specific reference to GTR in periodontal regenerative therapy.
GTR: is a technique for enhancing and directing cell growth to repopulate specific parts of the peridontium that have been damaged by periodontal disease, tooth disease, or trauma.
Tissue regeneration: by using membrane barriers and/or bone grafting materials in periapical surgery is an example of tissue engineering technology.
Most highlighted results:
•Regeneration of periapical tissues after periapical surgery requires:
•1) Recruitment of progenitor stem cells to differentiate into committed osteoblasts, PDL cells and cementoblasts
•2) Growth/differentiation factors as necessary signals for attachment, migration, proliferation of stem cells.
•3) Local microenvironmental cues such as adhesion molecules and EMC and associated noncollagenous protein molecules. ( figure 3 )
•In animal studies at 3 to 5 month observation, if membrane barriers were not used to cover the bony defects both buccally and lingually with through-and-through osseous defects, the defects were filled with fibrous connective tissue.
•Clinically, the best application of membrane barriers in periapical surgery appears to be in combined endo-perio or perio-endo lesions or large periapical lesions communicating with the alveolar crest.
•The nature of regenerated periapical tissues after the use of bone grafts in periapical surgery remains unknown.
•All reported outcome studies of periapical wound healing by using bone grafts in periapical surgery are short term (12 month).
•Calcium sulfate can serve as scaffold for new bone formation in periapical surgery.
•Combination of platelet-rich plasma and tri-calcium phosphate placed in a bony defect after periapical surgery was shown to enhance bone regeneration. The host’s blood clot provides an excellent natural scaffold for wound healing.