Normal wound healing occurs in four overlapping stages - hemostasis, inflammation, proliferation, and remodeling. In the oral cavity, these processes occur in an infectious environment. Among the pathogens found in the oral community, Aggregatibacter actinomycetemcomitans (Aa) constitutes a well-recognized periodontal pathogen responsible for expressing several virulence factors, which activate a host response. Aim This study investigated whether Aa’s presence can interfere with oral keratinocyte tissue healing in an in vitro wound healing model. Methods Two groups were defined: Group KO (n=5) and Group KO+Aa (n=5). The Aa (JP2 strains) were cultivated in anaerobiosis, and the total protein extract was obtained. The keratinocytes were cultivated with the medium of standard culture until their confluence. After confluence, plates were allocated to each group. With the pipette’s tip, a “scratch” was made in the middle of each well of the plate, and the cells were cultured at 37°C in a humidified atmosphere with 5% CO2. The cells received the stimulus according to groups, and, at times 0, 5, 10, 24, and 48 hours, the wound areas were visualized and standardly recorded using an inverted microscope. Results When analyzing the timeframe, differences in wound measurements indicate a faster closure in the control group compared to the KO+Aa group, although not statistically significant. However, upon examining the wound closure measures, it was observed that the Aa protein extract significantly reduced wound closure at 10 and 48 hours (p<0.05), negatively impacting the keratinocyte’s behavior. Conclusion In summary, it was demonstrated that the pathogen Aa can interfere with the re-epithelization in vitro. hemostasis inflammation proliferation remodeling cavity environment community (Aa wellrecognized recognized factors response Aas s model defined n=5 n5 n 5 (n=5 KOAa n=5. . JP2 JP (JP strains anaerobiosis obtained confluence pipettes pipette tip scratch “scratch plate 37C C 37 CO2 CO 0 24 4 microscope timeframe significant However measures 1 p<0.05, p005 p p<0.05 , 05 (p<0.05) behavior summary reepithelization re epithelization n= (n= 3 2 p00 p<0.0 (p<0.05 (n p0 p<0. (p<0.0 p<0 (p<0. p< (p<0 (p< (p

Abstract Cementum is the mineralized tissue covering the tooth root that functions in tooth attachment and post-eruptive adjustment of tooth position. It has been reported to be highly similar to bone in several respects but remains poorly understood in terms of development and regeneration. Here, we investigate whether cementocytes, the residing cells in cellular cementum, have the potential to be protagonist in cementum homeostasis, responding to endocrine signals and directing local cementum metabolism. Cells from healthy erupted human teeth were isolated using sequential collagenase/EDTA digestions, and maintained in standard cell culture conditions. A cementocyte-like cell line was cloned (HCY-23, for human cementocyte clone 23), which presented a cementocyte compatible gene expression signature, including the expression of dentin matrix protein 1 ( DMP1 ), sclerostin ( SOST ), and E11/gp38/podoplanin ( E11 ). In contrast, these cells did not express the odontoblast/dentin marker dentin sialoprotein ( DSPP ). HCY-23 cells produced mineral-like nodules in vitro under differentiation conditions, and were highly responsive to inorganic phosphate (Pi). Within the limits of the present study, it can be concluded that cementocytes are phosphate-responsive cells, and have the potential do play a key role in periodontal homeostasis and regeneration.

RESUMO A engenharia de tecidos é um campo contemporâneo da ciência, que visa criar condições baseadas em princípios de biologia celular e molecular, bioengenharia e biomateriais para regenerar tecidos. As células tronco mesenquimais apresentam altas taxas de proliferação e são capazes de se diferenciar, sob certas condições, em multi-linhagens, sugerindo que elas têm grande potencial para atuar no campo da regeneração. As células tronco derivadas de tecidos dentais são uma fonte alternativa adequada de células mesenquimais uma vez que são de fácil acesso e têm baixa morbidade para o doador. Estudos demonstraram que elas já foram isoladas e caracterizadas a partir de diversos tecidos tais como polpa dentária, dentes decíduos esfoliados, ligamento periodontal, gengiva, folículo dental e papila apical. Entretanto, os estudos demonstram que há heterogeneidade entre essas populações e não existe um método padrão para selecionar as células-tronco dentais mais apropriadas para procedimentos regenerativos. O objetivo desta revisão é apresentar o conhecimento atual dos vários tipos de células-tronco derivadas de dentes e discutir as novas perspectivas para seu uso na engenharia de tecidos periodontais.

ABSTRACT Tissue engineering is a contemporary field of science, which aims to create conditions based on principles of cell and molecular biology, bioengineering and biomaterials to regenerate tissues. Mesenchymal stem cells present high proliferation rates and are able to differentiate into multilineages under certain conditions, suggesting that they have great potential to act in regeneration field. Tooth derived stem cells are a suitable alternative source of mesenchymal cells once they are easily accessible and have poor morbidity to the donor. Studies showed that they have been isolated and characterized from diverse tissues such as dental pulp, exfoliated deciduous teeth, periodontal ligament, gingiva, dental follicle and apical papilla. However studies show that there is heterogeneity among these populations and there is no standard method to select the most appropriate tooth derived stem cells for regenerative procedures. The aim of this review is to present the current perspective of the multiple types of tooth-derived stem cells and to discuss the basis for their use in periodontal tissue engineering.