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Biomedical subjects

A M Polson

Publications and source records attributed to A M Polson.

16 recordsLinked to original sources
PubMed1992

Effect of metronidazole on experimental periodontitis: cell population characteristics.

Systemic administration of metronidazole during an experimental periodontitis resulted in significantly less active tissue destruction compared to drug-free animals. However, the size of the inflammatory infiltrates in both groups was similar. The present study assessed cell populations within the infiltrates of metronidazole receiving and drug-free animals. In the experimental group, metronidazole was administered orally to 4 squirrel monkeys (100 mg/kg body weight per day) for 17 days. After 3 days, marginal periodontitis was induced around maxillary and mandibular bicuspids and molars by tying silk ligatures at the gingival margins. In 4 monkeys of the drug-free control group, periodontitis was induced around similar teeth. Biopsies of the gingiva representing 3, 7 and 14 days of experimental periodontitis were taken in both groups. The total number of cells and the number of polymorphonuclear leucocytes (PMN's) were counted on one-micron sections. At 3 days after ligature placement, there were numerically less total cells and PMN's in the metronidazole receiving experimental group. At 7 and 14 days the total number of cells and the number of PMN's was significantly greater in the drug-free control group, where more active periodontal breakdown had occurred. These results emphasize the potentially destructive role of PMN's in acute bursts of tissue destruction.

Animals↗
PubMed1991

Histologic studies on the extension of the inflammatory infiltrate in human periodontitis.

This study was undertaken to re-examine early and recent morphologic descriptions of gingival and periodontal inflammation based on a study of gingival biopsies and block sections of human jaws. A collection of 350 autopsy and surgically retrieved jaw sections containing multiple teeth and displaying various stages of periodontal inflammation were subjected to routine histologic preparation and analyzed with step serial sections. 105 gingival biopsies, serially sectioned, including 15 clinically normal specimens, were also studied. The results of these investigations suggest that the inflammatory lesion extends into the alveolar process and elicits a response, often before evidence of crestal resorption or connective tissue attachment loss has occurred. Similarly, deep penetrations of inflammatory cells into the alveolar bone, periodontal ligament and periapical tissues, along with fibrosis and enlargement of the marrow spaces, were common findings with advancing disease. More widespread distributions of inflammatory cells than previously described were found in clinically normal gingiva, while in more inflamed gingiva, the inflammatory cell types found and their pattern of distribution varied greatly from individual to individual. These observations cast doubt on the perception of human periodontitis as a localized and marginal disease and suggest that its effects may be much more pervasive than previously thought.

Adult↗
PubMed1991

Correlations between periodontal tissue breakdown and cell populations.

The present study evaluated correlations between periodontal breakdown and cell populations during an experimental periodontitis. Periodontitis was induced by tying plaque retentive silk ligatures at the gingival margins of maxillary and mandibular bicuspids and molars of 4 squirrel monkeys. Periodontal destruction was evaluated at baseline, and 3, 7 and 14 days after ligature placement by measuring loss of connective tissue attachment and crestal alveolar bone. Cell populations were characterized at corresponding time points by counting polymorphonuclear leucocytes (PMNs), plasma cells and the total number of cells. At baseline, levels of connective tissue attachment and crestal alveolar bone were normal. At 3, 7 and 14 days, loss of attachment and loss of bone were statistically significant. At baseline PMNs and plasma cells were sparse. At 3, 7 and 14 days, the total number of cells and PMNs were statistically significantly increased compared to baseline. Periodontal tissue destruction was positively and strongly correlated with the number of PMNs. These correlations emphasize the potential role of PMNs during acute bursts of periodontal tissue destruction.

Animals↗
PubMed1979

Cell populations in the transseptal fiber region before, during and after experimental periodontitis in squirrel monkeys.

A study was designed to enumerate cell populations before, during and after experimentally induced periodontitis in squirrel monkeys. The clinically healthy gingival connective tissue adjacent to the sulcus contained populations of macrophages, plasma cells, lymphoid cells, and granulocytes, indicating that immune responses were probably in operation. Although these cell populations have been associated with tissue destruction, it is possible that they may serve to confine the antigens to the tissue adjacent to the sulcus, and reduce their spread apically. Active periodontitis was associated with the presence of granulocytes and macrophages in the transseptal fiber region. These cells are capable of causing the localized collagen degradation and bone resorption that occur during the destructive phase of the disease. Eight weeks after etiologic agents were removed, the cell populations in the transseptal fiber area returned to a level comparable with those in the pre-experimental, clinically healthy. This indicates that active periodontitis within the transseptal fiber region had ceased and repair had occurred.

Animals↗
PubMed1978

Osseous repair in infrabony periodontal defects.

The present investigation was undertaken to quantitate the osseous changes which occur throughout the entire circumferential extent of infrabony periodontal defects in patients with optimal plaque control. Fifteen defects were selected in nine patients. Periodontal surgery was scheduled after each patient had shown an ability to practice efficient plaque removal. Muco-periosteal flaps were raised and the osseous defects debrided. The dimensions of each defect were measured at several specific location points within the defect. The flaps were replaced at their original location and, post-operatively, optimal plaque control was maintained in the area (Mean Plaque Index 0.04). Six to 8 months after the initial surgery all areas were re-operated and the osseous defects were remeasured at the same specific location points. Each defect showed osseous regeneration at every location point. The mean initial osseous defect depth at a location point was 3.5 mm and the mean amount of bone regeneration which occurred was 2.5 mm. Crestal alveolar bone resorption occurred at almost half of the location points and averaged 0.7 mm. Eleven of the 15 defects had resolved completely. There were isolated areas where a shallow defect persisted in the remaining four defects. The behavior of an osseous defect throughout its circumferential extent was characterized by a combination of coronal bone regeneration (mean 77%) and marginal bone resorption (mean 18%). Infrabony periodontal defects may predictably remodel after surgical debridement and establishment of optimal plaque control.

Adult↗
PubMed1976

Alveolar bone regeneration after removal of inflammatory and traumatic factors.

In this investigation periodontal destruction was produced by a combination of inflammatory and traumatic factors. After the inflammation was resolved and the trama stopped, a significant amount of alveolar bone regeneration took place. The implications of these findings for the management of advanced periodontal disease are discussed.

Alveolar Process↗