Connective tissue regeneration to periodontally diseased teeth

237

There is still controversy as to the role of bone grafting materials in the formation of a new attachment apparatus and component tissues (bone, cementum, and periodontal ligament). The purpose of this study was to compare the healing of intrabony defects with and without the placement of decalcified freeze-dried bone allograft (DFDBA) in a nonsubmerged environment in humans. The most apical level of calculus on the root served as a histologic reference point to delineate root surfaces exposed to the oral environment and to measure new attachment apparatus and new component tissue formation. Free gingival grafts were placed over grafted and nongrafted defects to retard epithelial migration. Biopsies were obtained at 6 months and regeneration was evaluated histometrically. Data from 12 patients with 32 grafted and 25 nongrafted defects were submitted for statistical analysis. Results indicate that in nongrafted defects, a long junctional epithelium formed along the entire length of exposed root surfaces and often extended apical to the calculus reference notch. Free gingival grafts did not enhance regeneration of a new attachment apparatus, new cementum, new connective tissue, or new bone in nongrafted defects. The formation of a new attachment apparatus was observed when intrabony defects were grafted with DFDBA (x1.21 mm); significantly more new attachment apparatus (P less than .005), new cementum (P less than .005), new connective tissue (P less than .05), and new bone (P less than .0001) formed in intrabony defects grafted with DFDBA than in nongrafted defects. There was a greater chance for regeneration of a new attachment apparatus and component tissues in grafted defects than in nongrafted defects. New cellular cementum formed on old cementum and dentin but more often formed over both in the same defect). The periodontal ligament was more frequently oriented perpendicular to the root; there was greater loss in alveolar crest height in nongrafted than grafted defects (P less than .05); and extensive root resorption, ankylosis, and pulp death were not observed in grafted or nongrafted defects.

Section: Root Resorption and Ankylosismentioning

confidence: 97%

Histologic Evaluation of New Attachment Apparatus Formation in Humans

Bowers

Chadroff²,

Carnevale³

et al. 1989

237

“…2 This histological evidence is supported by clinical results that include bone fill of osseous defects and gain of clinical attachment levels. Currently, several materials have met these criteria in the human model: intraoral autogenous bone, [3][4][5] demineralized freeze-dried bone allograft (DFDBA), 6,7 DFDBA with bone morphogenetic protein (BMP), 8 barrier membranes, [9][10][11][12] citric acid application, 13 bovine-derived xenograft (BDX), 14,15 and enamel matrix derivative (EMD). 16,17 EMD and BDX have recently been introduced as part of the armamentarium for regenerative therapy.…”

mentioning

confidence: 99%

Clinical Comparison of an Enamel Matrix Derivative Used Alone or in Combination With a Bovine‐Derived Xenograft for the Treatment of Periodontal Osseous Defects in Humans

Velasquez-Plata

Scheyer

Mellonig

2002

105

124

“…Organized clot: plasma protein layer not visible, organized meshwork consisting of platelets, fibrin and erythrocytes. 4 …”

Section: Methodsmentioning

confidence: 97%

Scanning Electron Microscopy Observations of Initial Clot Formation on Treated Root Surfaces

Steinberg

Willey

1988

This study presents the morphological sequence of events in initial blood clot formation on various root surfaces of freshly extracted human teeth. Four teeth with periodontal disease (PD) and three teeth without PD were extracted and the roots sectioned into halves. Those root surfaces with PD had four treatment areas: (1) intact periodontal ligament (PDL), (2) unplanned PD, (3) PD plus planed, (4) PD plus planed plus application of pH 1 citric acid (CA). The roots with no PD had three treatment areas: (1) intact PDL, (2) planed, (3) planed plus CA. Both root halves were reinserted together into the original extraction site. Each root half was then removed at either zero, one, two or four minutes and prepared for scanning electron microscope (SEM) evaluation. SEM observations suggested that plasma proteins were deposited initially on all root surfaces. Platelets and erythrocytes enmeshed in fibrin deposited most rapidly and consistently over the plasma protein layer where intact PDL was present. Similar observations were noted on the planed plus CA surfaces and appeared to occur at an earlier time than on the planed-only surfaces. A constant feature at all time periods was the absence of organized clot formation over the plaque-free zone of the PD root surfaces. By two minutes all surfaces, except the plaque-free zone of the PD area, appeared to have clot lysis occurring. While clot formation appeared to occur more rapidly over surfaces in the non-PD roots, no marked morphological differences in clot formation were observed between PD and non-PD teeth with similar root surface treatments.