Expression of epithelial growth factors and of apoptosis-regulating proteins, and presence of CD57+ cells in the development of inflammatory periapical lesions.

OBJECTIVE: The mechanisms that stimulate the proliferation of epithelial cells in inflammatory periapical lesions are not completely understood and the literature suggests that changes in the balance between apoptosis and immunity regulation appear to influence this process.To evaluate the expression of the epidermal growth factor (EGF), its receptor (EGFR) and of the keratinocyte growth factor (KGF), the presence of CD57+ cells, the epithelial cell proliferation index, and the expression of the Bcl-2 protein in inflammatory periapical lesions (IPL) at different stages of development. METHODOLOGY: Our sample was composed of 52 IPLs (22 periapical granulomas - PG - and 30 periapical cysts - PC), divided into three groups: PGs, small PCs, and large PCs. Specimens were processed for histopathologic and immunohistochemical analyses. Sections were evaluated according to the amount of positive staining for each antibody. RESULTS: We found no significant differences among the groups regarding Bcl-2 (p=0.328) and Ki-67 (p>0.05) expression or the presence of CD57+ cells (p=0.748). EGF (p=0.0001) and KGF (p=0.0001) expression was more frequent in PCs than in PGs, and CD57+ cells were more frequent in IPLs with intense inflammatory infiltrates (p=0.0001). We found no significant differences in KGF (p=0.423), Bcl-2 (p=0.943), and EGF (p=0.53) expression in relation to inflammatory infiltrates or to the type of PC epithelial lining, but observed greater KGF expression (p=0.0001) in initial PCs. EGFR expression was similar among the groups (p>0.05). CONCLUSION: More frequent EGF and KGF expression in PCs and the greater presence of CD57+ cells in lesions with intense inflammatory infiltrates suggest that these factors influence IPL development. The greater KGF expression in initial PCs suggests its importance for the initial stages of PC formation.

Expression of epithelial growth factors and of apoptosis-regulating proteins, and presence of CD57+ cells in the development of inflammatory periapical lesions

Abstract The mechanisms that stimulate the proliferation of epithelial cells in inflammatory periapical lesions are not completely understood and the literature suggests that changes in the balance between apoptosis and immunity regulation appear to influence this process. Objective: To evaluate the expression of the epidermal growth factor (EGF), its receptor (EGFR) and of the keratinocyte growth factor (KGF), the presence of CD57+ cells, the epithelial cell proliferation index, and the expression of the Bcl-2 protein in inflammatory periapical lesions (IPL) at different stages of development. Methodology: Our sample was composed of 52 IPLs (22 periapical granulomas - PG - and 30 periapical cysts - PC), divided into three groups: PGs, small PCs, and large PCs. Specimens were processed for histopathologic and immunohistochemical analyses. Sections were evaluated according to the amount of positive staining for each antibody. Results: We found no significant differences among the groups regarding Bcl-2 (p=0.328) and Ki-67 (p>0.05) expression or the presence of CD57+ cells (p=0.748). EGF (p=0.0001) and KGF (p=0.0001) expression was more frequent in PCs than in PGs, and CD57+ cells were more frequent in IPLs with intense inflammatory infiltrates (p=0.0001). We found no significant differences in KGF (p=0.423), Bcl-2 (p=0.943), and EGF (p=0.53) expression in relation to inflammatory infiltrates or to the type of PC epithelial lining, but observed greater KGF expression (p=0.0001) in initial PCs. EGFR expression was similar among the groups (p>0.05). Conclusion: More frequent EGF and KGF expression in PCs and the greater presence of CD57+ cells in lesions with intense inflammatory infiltrates suggest that these factors influence IPL development. The greater KGF expression in initial PCs suggests its importance for the initial stages of PC formation.

Infecção secundária e persistente e sua relação com o fracasso do tratamento endodôntico / The relationship between secondary and persistent infections and failure of endodontic treatments

Objetivo: O objetivo da presente revisão de literatura foi discutir a relação entre a infecção secundária e a infecção persistente e o insucesso endodôntico. Material e Métodos: Foi realizada uma pesquisa bibliográfica abrangendo artigos de revisão e de pesquisa, a partir de buscas em bases de dados SciELO, Periodicos CAPES, PubMed e MedLine utilizando os seguintes descritores: endodontia, periodontite periapical, infecção. Foram incluídos artigos publicados no período de 1990 a 2016 e escritos nas línguas inglesa e portuguesa. Além disso, os artigos foram selecionados após a leitura do seu resumo e a verificação da adequação do mesmo ao conteúdoa dessa revisão. Resultados: A literatura atual parece concordar que a desinfecção inadequada do sistema de canais radiculares e mecanismos de adaptação e resistência microbiana desempenham papel importante no insucesso endodôntico. Porém, a mesma ainda é controversa com relação ao papel do E. faecalis nesses casos de insucesso. Conclusão: Pode-se concluir, dentro das limitações do presente estudo, que o respeito às técnicas endodônticas é fundamental para obter sucesso e que novos estudos, utilizando proteômica, podem contribuir para esclarecer quais os principais micro-organismos envolvidos, bem como seu mecanismo de ação.

Objective: The aim of the present literature review was to discuss the relationship between secondary infections and persistent infections and endodontic treatment failure. Materials and Methods: We conducted a literature search including review articles and original research by searching the SciELO, Periódicos CAPES, PubMed and Medline databases using the following descriptors: endodontics, apical periodontitis, and infection. We included articles that were published between 1990 and 2016, and written in either English or Portuguese. Articles were selected after reading their abstracts and verifying their relevance to the review content. Results: The current literature seems to agree that inadequate disinfection of the root canal system, along with mechanisms of bacterial adaptation and resistance play an important role in endodontic treatment failure. However, there is still controversy regarding the role of Enterococcus faecalis in these failures. Conclusion: From the present study's findings, we can conclude that strict compliance to the proper endodontic techniques is fundamental for treatment success. Additionally, we believe that further studies using proteomic techniques may help fill the gaps regarding the main microorganisms associated with endodontic treatment failure as well as their mechanisms of action.