Pulp capping materials exert an effect on the secretion of IL-1β and IL-8 by migrating human neutrophils

Pulp repair is a complex process whose mechanisms are not yet fully understood. The first immune cells to reach the damaged pulp are neutrophils that play an important role in releasing cytokines and in phagocytosis. The objective of this study was to analyze the effect of different pulp-capping materials on the secretion of interleukin-1 beta (IL-1&#946;) and interleukin-8 (IL-8) by migrating human neutrophils. Neutrophils were obtained from the blood of three healthy donors. The experimental groups were calcium hydroxide [Ca(OH)2], an adhesive system (Single Bond), and mineral trioxide aggregate (MTA). Untreated cells were used as control. Transwell chambers were used in performing the assays to mimic an in vivo situation of neutrophil chemotaxis. The pulp-capping materials were placed in the lower chamber and the human neutrophils, in the upper chamber. The cells were counted and the culture medium was assayed using ELISA kits for detecting and quantifying IL-1&#946; and IL8. The data were compared by ANOVA followed by Tukey's test (p < 0.05). The secretion of IL-8 was significantly higher in all groups in comparison to the control group (p < 0.05). The adhesive system group showed higher IL-8 than the MTA group (p < 0.05). The secretion of IL-1&#946; was significantly greater only in the MTA group (p < 0.001). It was concluded that only MTA is able to improve the secretion of IL-1&#946;, and all materials tested increased IL-8 secretion. These results combined with all the other biological advantages of MTA indicate that it could be considered the material of choice for dental pulp capping.(FAPESP) São Paulo Research Foundatio

Interleukin-1 beta and interleukin-8 in healthy and inflamed dental pulps

After aggression to the dental pulp, some cells produce cytokines in order to start and control the inflammatory process. Among these cytokines, interleukin-1 beta (IL-1&#946;) and interleukin-8 (IL-8) emerge as important ones. OBJECTIVE: The purpose of this study was to analyze the location, distribution and concentration of these cytokines in healthy and inflamed dental pulps. MATERIAL AND METHODS: Twenty pulps, obtained from healthy third molars (n=10) and from pulpectomies (n=10) were used for the study, with half of each group used for immunohistochemistry and half for protein extraction and ELISA assays. Fibroblasts obtained from healthy dental pulps, stimulated or not by Escherichia coli lipopolysaccharide (LPS), in order to simulate aggression on the cell cultures, were also used and analyzed by ELISA for IL-1&#946; and IL-8 as complementary information. Data obtained from immunohistochemistry were qualitatively analyzed. Data obtained from ELISA assays (tissue and cells) were statistically treated by the t-test (p<0.05). RESULTS: Immunohistochemically, it was observed that inflamed pulps were strongly stained for both cytokines in inflammatory cells, while healthy pulps were not immunolabeled. ELISA from tissues quantitatively confirmed the higher presence of both cytokines. Additionally, cultured pulp fibroblasts stimulated by LPS also produce more cytokines than the control cells. CONCLUSIONS: It may be concluded that inflamed pulps present higher amounts of IL-1&#946; and IL-8 than healthy pulps and that pulp fibroblasts stimulated by bacterial LPS produce higher levels of IL-1&#946; and IL-8 than the control group.(FAPESP) São Paulo Research Foundatio

Mechanical-physicochemical properties and biocompatibility of catechin-incorporated adhesive resins

Several anti-proteolytic dentin therapies are being exhaustively studied in an attempt to reduce dentin bond degradation and improve clinical performance and longevity of adhesive restorations. Objectives: This study assessed the effect of epigallocatechin-3-gallate (EGCG) on long-term bond strength when incorporated into adhesives. Material and Methods: Adhesive systems were formulated with EGCG concentrations of 0 wt%: (no EGCG; control); 0.5 wt% EGCG; 1.0 wt% EGCG, and 1.5 wt% EGCG. Flexural strength (FS), modulus of elasticity (ME), modulus of resilience (MR), compressive strength (CS), degree of conversion (DC), polymerization shrinkage (PS), percentage of water sorption (%WS), percentage of water solubility (%WL) and cytotoxicity properties were tested. Dentin microtensile bond strength (µTBS) was evaluated after 24 h and again after 6 months of water storage. The adhesive interface was analyzed using scanning electron microscopy (SEM). Results: No significant differences were found among the groups in terms of FS, ME, MR, CS and PS. EGCG-doped adhesives increased the DC relative to the control group. EGCG concentrations of 1.0 wt% and 0.5 wt% decreased the WS of adhesives. WL decreased in all cases in which EGCG was added to adhesives, regardless of the concentration. EGCG concentrations of 1.0 wt% and 0.5 wt% reduced cytotoxicity. EGCG concentrations of 1.0 wt% and 0.5 wt% preserved µTBS after 6 months of storage, while 1.5 wt% EGCG significantly decreased µTBS. SEM: the integrity of the hybrid layer was maintained in the 0.5 wt% and 1.0 wt% EGCG groups. Conclusion: EGCG concentrations of 1.0 wt% and 0.5 wt% showed better biological and mechanical performance, preserved bond strength and adhesive interface, and reduced cytotoxicity

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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Human pulp fibroblasts response to substances leached from direct pulp capping materials

Cavalcanti, BN. Resposta de fibroblastos de polpa humanos frente a substâncias liberadas por capeadores pulpares diretos [Tese de Doutorado]. São Paulo: Faculdade de Odontologia da USP; 2003. RESUMO O objetivo do presente estudo foi o de avaliar os efeitos citotóxicos de substâncias liberadas durante a aplicação de materiais utilizados em capeamento pulpar direto, sobre fibroblastos de polpa dentária humana. Utilizou-se para o experimento meios condicionados pelas substâncias a serem testadas, divididas nos grupos a seguir: grupo I: controle (meio de cultivo sem condicionamento); grupo II: cimento de hidróxido de cálcio; grupo III: adesivo dentinário; grupo IV: ácido ortofosfórico a 37%. O condicionamento foi realizado, colocando-se meio de cultivo fresco sobre os materiais de modo que a presa (grupo II), polimerização (grupo III) ou o contato direto (grupo IV) liberassem substâncias para esse meio de cultivo. Esse meio era colocado sobre as células durante todo o experimento, excetuando-se o grupo IV, onde o contato foi feito por um período de 15 segundos, conforme recomendações clínicas. Posteriormente foram realizadas contagens em hemocitômetro pelo método de exclusão por azul de Trypan, que cora somente as células mortas. As contagens foram realizadas em períodos de 0, 6, 12 e 24 horas para o experimento de viabilidade celular (curto prazo), onde se avaliou o percentual de células vivas sobre o total de células, e em períodos de 1, 3, 5 e 7 dias para o experimento de sobrevivência celular, no qual se avaliou o número absoluto de células vivas. Observou-se que as substâncias liberadas pelo adesivo dentinário são citotóxicas em qualquer período, diminuindo consideravelmente a viabilidade celular e afetando suas curvas de crescimento. Aquelas liberadas pelo ácido ortofosfórico a 37% provocam diminuição da viabilidade somente nos primeiros momentos do contato com as células, enquanto as substâncias liberadas durante a presa do hidróxido de cálcio não são citotóxicas em nenhum momento.The purpose of the present study was to evaluate the cytotoxic effects of substances leached during the use of direct pulp capping materials, on human pulp fibroblasts. There were used cell culture mediums conditioned by the test materials, as follows: group I: control (fresh medium without conditioning); group II: calcium hydroxide cement; group III: bonding system; group IV: 37% orthophosphoric acid. The medium conditioning was made, pouring the fresh conditioning medium on the materials, in order that its setting (group II), polymerization (group III) or the direct contact (group IV) would be able to leach substances to this culture medium. These conditioned mediums were put on the cells for the entire experiment, excepting the group IV, in which the mediums were put in contact with the cells for 15 seconds, following clinical recommendations. Cell counting was performed in hemocytometer, using the Trypan blue exclusion method, which mark only the dead cells. These counting was made at experimental times of 0, 6, 12 and 24 hours for the cell viability assay (short term), where it is evaluated the percentage of live cells on the total number of cells, and at experimental times of 1, 3, 5 and 7 days for the survival assay, in which is evaluated the absolute number of live cells. It was observed that the substances leached by the bonding system are cytotoxic at all experimental times, decreasing significantly the cell viability and affecting its growing rate. Those leached by the 37% orthophosphoric acid decreased the cell viability only at the first contact with the cells, and the substances leached during the setting of the calcium hydroxide cement are not cytotoxic

Biologia pulpar: da agressão à reparação

The study of the dental pulp can be extended from factors related to its aggression to those related to new concepts of regeneration. The purpose of this compilation of studies is to present the evolution of a research subject from damage to repair. Innitially, studies will demonstrate the ability of dental procedures to generate heat and consequently affect the dental pulp. In sequence, studies will also present some effects of different pulp capping materials on dental pulp cells, related to the cytotoxicity of these materials and inflammatory potential. Finally, as the subject is emmerging and gaining importance in the literature, this compilation will present data from recent studies on the role of dental pulp progenitor cells in the regeneration and repair of dental pulp, as well as an alternative for a scaffold that could be used for clinical translation of research in the field. In summary, dentists must be aware of these different aspects and that the knowledge on factors and mechanisms involved in the aggression of the dental pulp can also serve as basis for understanding aspects for regeneration.O estudo da polpa dentária pode se desdobrar desde fatores relacionados à sua agressão até àqueles relacionados a novos conceitos de regeneração. A proposta desta compilação de estudos é a de apresentar a evolução de uma linha de pesquisa desde a agressão até o reparo. Inicialmente, estudos demonstrarão a capacidade de procedimentos odontológicos em gerar calor e consequentemente afetar a polpa dental. Em sequência, estudos apresentarão alguns efeitos de diferentes materiais de capeamento pulpar em células da polpa dentária, relacionados à citotoxicidade e potencial inflamatório destes materiais. Finalmente, como um assunto emergente que vem ganhando importância na literatura, esta compilação apresentará dados de estudos recentes sobre o papel de células progenitoras na regeneração e reparo da polpa dentária, bem como uma alternativa de scaffold que pode ser utilizado para translação clínica da pesquisa neste campo. Em resumo, o profissional de odontologia deve estar atento para estes diferentes aspectos e para o fato de que o conhecimento de fatores e mecanismos envolvidos na agressão da polpa dentária podem também servir de base para o entendimento dos aspectos da regeneração

A hydrogel scaffold that maintains viability and supports differentiation of dental pulp stem cells

Objectives: The clinical translation of stem cell-based Regenerative Endodontics demands further development of suitable injectable scaffolds. Puramatrix™ is a defined, self-assembling peptide hydrogel which instantaneously polymerizes under normal physiological conditions. Here, we assessed the compatibility of Puramatrix™ with dental pulp stem cell (DPSC) growth and differentiation. Methods: DPSC cells were grown in 0.05–0.25% Puramatrix™. Cell viability was measured colorimetrically using the WST-1 assay. Cell morphology was observed in 3D modeling using confocal microscopy. In addition, we used the human tooth slice model with Puramatrix™ to verify DPSC differentiation into odontoblast-like cells, as measured by expression of DSPP and DMP-1. Results: DPSC survived and proliferated in Puramatrix™ for at least three weeks in culture. Confocal microscopy revealed that cells seeded in Puramatrix™ presented morphological features of healthy cells, and some cells exhibited cytoplasmic elongations. Notably, after 21 days in tooth slices containing Puramatrix™, DPSC cells expressed DMP-1 and DSPP, putative markers of odontoblastic differentiation