Costa, Antonio de Lisboa LopesBrito, Clarice Pereira de2020-07-142020-07-142020-03-02BRITO, Clarice Pereira de. Expressão imuno-histoquímica da p53 em líquen plano da mucosa oral. 2020. 54f. Dissertação (Mestrado em Ciências Odontológicas) - Centro de Ciências da Saúde, Universidade Federal do Rio Grande do Norte, Natal, 2020.https://repositorio.ufrn.br/jspui/handle/123456789/29617Lichen planus (LP) is a common immunologically mediated chronic disease, of unknown origin, which affects the skin and often the oral mucosa, among other mucous membranes. When it occurs in mouth, it is called oral lichen planus (OLP), and it is presented as a spontaneous onset disease, with a recurrent character. The objective of this research was to analyze the immunohistochemical expression of p53 in reticular and erosive oral lichen planus and fibrous hyperplasia, in order to perform a comparative analysis between the groups. The cross-sectional and retrospective, descriptive and semi-quantitative study of the immunohistochemical expression of p53, in 20 samples of reticular fluid, oral, 20 of oral erosive fluid and 20 of fibrous hyperplasia (control). In the statistical analysis, Kruskall-Wallis (KW) and Mann-Whitney (U) non-parametric tests were applied. The level of significance was set at 5% (p <0.05). It was observed that marking was present in all cases of erosive OLP (100%), in 17 cases of reticular OLP (85%) and in 15 cases of HF (78.9%). The cases of erosive OLP showed a higher nuclear immunoexpression of p53, compared to cases of reticular OLP, this difference being statistically significant (p <0.001). Likewise, cases of erosive OLP, when compared to HFs, showed higher nuclear immunoexpression of p53, with a statistically significant difference (p = 0.002). However, there was no statistically significant difference (p = 0.423) between reticular OLP and HFs, regarding to nuclear immunoexpression of p53. It can be concluded that cases of erosive oral lichen planus are more likely to malignant transformation compared to the reticular type and normal oral mucosa, since there is higher immunoexpression of this protein, which is clinically associated with several tumors of the human body.Acesso AbertoLíquen plano oralp53Imuno-histoquímicamasterThesisCNPQ::CIENCIAS DA SAUDE::ODONTOLOGIA