Immunohistochemical study of experimentally drug-induced gingival overgrowth.

The increasing frequency of using in the medical practice drugs that have the potential to induce gingival overgrowth (GO) and the existence of many unknown aspects in GO etiopathogenesis have prompted us to carry out this immunohistochemical experimental animal study. We conducted a cell proliferation study by Ki67 immunostaining and a cytokeratin (CK) study using anti-pan-CK AE1∕AE3 and anti-MNF116 antibodies, investigating the differences induced by different classes of drugs that are more frequently involved in the induction of GO. The results of our study indicate that CK AE1∕AE3 plays an important role not only in normal cellular proliferation, but also in hypertrophic tissues, and can be considered a marker of the proliferative process occurring in GO. Immunostaining for the anti-MNF116 antibody was weaker and inconsistent in intensity compared to anti-CK AE1∕AE3 antibody, its staining pattern appearing as diffuse or zonal.

Experimental animal model in a histological study of drug-induced gingival overgrowth.

Gingival overgrowth (GO) is a pathology with important aesthetic and functional implications and with a multifactorial pathogenesis. Incriminated etiological factors include antihypertensive, antiepileptic and immunosuppressant medication. We aimed to evaluate the induction of gingival overgrowth on experimental rats, depending on the drug type, dose and duration. In the research conducted by us, the increase in gingival tissue production occurred gradually, depending on the administered medication and the time elapsed after its start. The study conducted shows that experimentally induced gingival overgrowth of the administered drugs is made possible by altering tissue homeostasis through altering the fibrocyte cell populations involved in the tissular turnover as well as those involved in the inflammatory process. A better understanding of the pathogenesis of this undesirable effect may lead to the development of improved management strategies for preventing it, or reducing it through non-surgical methods.

Clinical, imagistic and histopathological study of chronic apical periodontitis.

Periapical lesions are among the most frequent periodontal pathologies in human teeth, generally called apical periodontitis. Apical periodontitis is a continuation of the endodontic space infection and it is manifested as a response of the host defense against the microbial action. It may determine local inflammation, hard tissue resorption, destruction of other periapical tissues. The preliminary diagnosis of chronic periapical lesions is based on the clinical symptoms and imagistic investigation, which represent a reliable diagnosis instrument, but the histological investigation remains essential for a certain diagnosis. We performed a clinical and histological study of the periapical lesions, evaluating the various clinical and imagistic aspects and we compared them with the results of the histological examination, in order to establish the correspondence between the clinical-imagistic aspects and the morphological ones. The relation between the histological aspects, the clinical signs and imagistic aspects may provide valuable data both for establishing an accurate diagnosis and for adopting the most efficient treatment.

Study of some invasiveness markers as pathogenic factors in oral pseudoepitheliomatous hyperplasia.

Pseudoepitheliomatous hyperplasia is a benign reactivated epithelial lesion secondary to another pathology, whose incidence is difficult to establish. There still exist controversies regarding the origin and pathogenesis of these lesions. For this purpose, we performed an immuno-histochemical study upon 20 cases of oral pseudoepitheliomatous hyperplasia associated with inflammatory and neoplastic conditions, investigating a series of markers with a possible pathogenic potential in developing this type of lesions. Thus, the immunoreactivity study for ß-catenin showed the presence of a membrane reactivity in all the stratum spinosum and a predominantly cytoplasmatic reactivity, more rarely a nuclear one, in the cells of the basal stratum cells, especially in the epithelial apices that descend deeply in the chorion. Instead, in the case of vimentin, the reactivity was present only in the epithelial apices, especially in the peripheral cells, in comparison to the central ones, and especially in the cases where the epithelial apices descended deeply in the sublesional chorion. Moreover, we observed that the MMP9 reactivity in pseudoepitheliomatous hyperplasia lesions was present in the cells at the epithelium-chorion interface and especially in the epithelial apices that descend deeply into the chorion, and also in the epithelial chorion and networks. The study for CXCR4 immuno-reactivity showed a good reactivity in almost all layers of this hyperplastic lesion, with a maximum reactivity especially inside the epithelial apices that descend deeply in the sublesional chorion. Such an immunoprofile suggests the ability of the oral epithelial cells to undergo an epithelial mesenchymal transition process, thus acquiring mesenchymal characteristics through which it deeply migrates in the subadjacent chorion and contributes to the formation of epithelial apices in pseudoepitheliomatous hyperplasia. Moreover, the invasive ability of these lesions is also given by the average quantity of matrix metalloproteinases present in the epithelium-chorion interface determined by the activation of CXCR4 receptors at this level.