Orientation of Gingival Fibroblasts in Simulated Periodontal Spaces in Vitro

Abstract

The present study examined the orientation of gingival fibroblasts in simulated periodontal spaces in vitro. Extracted human teeth were root planed followed by root resection and root canal instrumentation. The middle and cervical thirds of each root were cut transversely to create 600-micron thick sections. Cortical bovine bone was cut, sectioned and contoured to create bone rings 600 micron thick with an internal diameter large enough to accommodate a root slice leaving a circumferential space varying from approximately 0.1 to 1.0 mm. Root slices and bone rings were incubated in a solution of collagenase and hyaluronidase to remove all remaining soft tissue and partially demineralized in EDTA (18%) for 30 minutes. Human gingival fibroblasts (HGF) were plated to confluency in tissue culture dishes. The dentin slices were then gently placed over the HGF monolayer along with bone rings around them to create simulated periodontal spaces. Control root slices were placed without bone rings around them. Cultures were maintained under standard tissue culture conditions. Representative specimens were obtained after 2, 3 and 4 weeks of culture and processed for scanning electron microscopy (SEM). At 2 weeks, the HGF had formed sheets of cells attached to the periphery of the root slices at one end and to the inner surface of bone rings at the other end. The orientation of cell sheets varied from being perpendicular to the periphery of the slice to oblique. At 3 and 4 weeks, the density and size of cell sheets increased and the orientation was maintained.(ABSTRACT TRUNCATED AT 250 WORDS)

Light and electron microscopic evaluation of biocompatibility, resorption and penetration characteristics of human collagen graft material

“…This in vitro interaction of fibroblasts with the extracellular matrix components has been proposed as a dynamic process which is integral to the formation of an oriented fibre system. A similar mechanism is responsible for the orientation of connective tissue in vivo (Harris et al 1981, Stopak et al 1982, such as is seen in the periodontal ligament (Stopak et al 1982, Aukhil et al 1986). The attachment of fibroblasts and fibroblast-like cells to the pre-viously denuded root surface, followed by orientation of these cells and their connective tissue matrix, may contribute to the new attachment apparatus in cases where periodontal disease has been treated surgically.…”

Periodontal regeneration: root surface demineralization

“…Cells began to migrate towards and attach to the root slices almost immediately following culturing of the fibroblasts with the root slices. Demineralized surfaces facilitated the attachment, migration and contraction fibroblasts, which led to the development of an orientated fiber attachment system between the demineralized surfaces (6,8,32,(78)(79)(80).…”

“…Pettersson & Aukhil (77) evaluated the effects of citric acid treatment of roots on the formation of new connective tissue attachment when progenitor cells from the periodontal ligament were allowed to populate the root surface. Using the concept of guided tissue regeneration, fenestration wounds were created on the buccal aspects of mandibular premolars in 6 beagle dogs. The exposed root surfaces were scaled and treated with either citric acid for 3 min or distilled water.…”

Long‐term culture of human periodontal ligament cells with autologous root discs

“…In appropriate experiments using dogs, monkeys and humans, it was siiown that primary contact of the proliferating periodonta] iigament with that root surface results in the formation of a new tissue resembling ceiiular cementum, and of collagen fibers whicii seem to arise from its surface (2,3). As a iarge number of biologicai questions involved remain unresoived, an in vitro model was proposed for studying problems of cell and coiiagen fiber attaciimeot and fiber orientation to and between opposing root surfaces (4)(5)(6)(7)(8)(9)(10). However, this modei was created from cell and tissue components derived from different species (rat, pig, human) and incompatible tissues (gingiva, calvaria, roots of teeth).…”

“…However, this modei was created from cell and tissue components derived from different species (rat, pig, human) and incompatible tissues (gingiva, calvaria, roots of teeth). Furthermore, many of the reported studies relied on rather short periods of culturing and some on disputable tissue evaluation (8,10).…”