Immunohistochemical Expression of Extracellular Matrix Components of Normal and Healing Periodontal Tissues in the Beagle Dog

Abstract

Periodontal regeneration requires formation of periodontal tissues lost due to periodontal disease. To better understand the formation of new periodontal tissues during periodontal repair and regeneration, immunohistochemical expression of extracellular matrix components of normal as well as healing periodontal tissues was evaluated and compared using the avidin-biotin complex immunohistochemical technique. For this purpose, horizontal furcation defects were created around mandibular P2 and P4 of 6 dogs after extraction of P1 and P3. The root surfaces were conditioned with citric acid and expanded polytetrafluoroethylene (ePTFE) membranes were placed and retained 0.5 mm above the cemento-enamel junction. The mucoperiosteal flaps were sutured in a coronal position. Two animals were sacrificed at 2, 4, and 8 weeks, and mesio-distal tissue slices containing normal or healing periodontal tissues were demineralized, dehydrated, and embedded in paraffin. Immunohistochemical localization of type I collagen (CI), fibronectin (FN), secreted protein, acidic and rich in cysteine (SPARC), vitronectin (VN), and bone sialoprotein (BSP) was performed on 6 microns thick sections. Morphological results demonstrated that at 2 weeks after defect creation, lesions were filled primarily with granulation tissue which was gradually replaced by newly-formed fibrous connective tissue, periodontal ligament (PDL), cementum, and bone between 4 and 8 weeks. The results of immunohistochemical study revealed that at 2 weeks the granulation tissue, especially in the intercellular spaces of inflammatory cells, was intensively stained for FN and VN. At 4 and 8 weeks, staining for CI, FN, and VN was found in fibrous connective tissue, the newly-formed PDL, cementum, and osteoid. Further the attachment zone of the PDL collagen fibers to cementum showed intense staining for FN. Immunostaining for SPARC was positive in the new PDL, cementum, and bone, while staining for BSP was restricted to the new cementum and bone. Interestingly, the PDL, especially in areas adjacent to active bone formation, demonstrated intense staining for BSP. However, fibrous connective tissue and PDL proper were unstained for BSP. These results indicate that FN and VN are involved in the early stages of periodontal repair, and periodontal regeneration is achieved through formation of periodontal tissues that are composed of different matrix components specific to different types of periodontal tissues.

Effect of Early Membrane Removal on the Treatment of Mandibular Class II Furcation Defects - A Controlled Clinical Trial with Re-entry after 12 Months

“…After 14 days, the tissue can present new collagen fibers, with an organization indicative of attachment to the dentin. Describing the tissues formed at 2 weeks of wound healing after GTR, Matsuura et al (21) reported that the defect was occupied predominantly by granulation tissue composed of numerous inflammatory cells and blood vessels, as well as formation of a fine layer of connective tissue between the granulation tissue and the root surface. At this stage, there is no significant bone or cementum formation.…”

Apatite Microtopographies Instruct Signaling Tapestries for Progenitor-Driven New Attachment of Teeth

“…The periodontal ECM is rich in collagen, fibronectin, tenascin, periostin, and other matrix molecules. 4,5 Collagen I is the principal protein component of Sharpey's fibers 6 and periostin is an indicator molecule of a functional PDL, as its expression changes dynamically in response to tension and compression. 7 Other periodontal glycoproteins such as fibronectin and tenascin provide arginin-glycine-aspartic acid (RGD) motifs for cell adhesion.…”

Periodontal regeneration following transplantation of proliferating tissue derived from periodontal ligament into class III furcation defects in dogs

“…Various surgical procedures have been developed for healing class II or III furcation defects (4,6), and various bone grafts and alloplastic materials have been transplanted (5,24,29); however, ankylosis, resorption, and long epithelial attachment are observed in alloplastic material-applied cases (8). It has been demonstrated that GTR is capable of successfully closing class III furcation defects in a dog model (11,17,18); however, the regeneration of class III furcation defects is often incomplete, even when GTR is employed, suggesting that this treatment is not effective for large, class III furcation defects (15,21,22), as it depends on natural healing ability. Since pPDL is basically capable of synthesizing periodontal tissue after transplantation, this treatment may be applicable to large periodontal tissue defects.…”