Differential cytotoxic effects on odontoblastic cells induced by self-adhesive resin cements as a function of the activation protocol.

OBJECTIVES: To evaluate the cytotoxic effects of exposing odontoblast cells to a variety of commercial self-adhesive cements polymerized using different activation modes. METHODS: Five cements: MaxCem Elite (MAX), Bifix SE (BSE), G-Cem LinkAce (GCE), Clearfil SA Luting (CAS), and RelyX U200 (U200) were mixed, dispensed into molds, and distributed in groups, according to polymerization protocols: immediate photoactivation; delayed photoactivation (10min self-curing plus light-activation); and chemical activation (no light exposure). Immortalized rat odontoblast cells (MDPC-23) were cultured. Cell viability was assessed by Trypan Blue staining and total cell death was assessed by annexin V-APC/7-AAD double staining and flow cytometry. Volatilized compounds from polymerized specimens of cements were evaluated by gas chromatography/mass spectrometry (GC-MS). Data was analyzed with 2-way ANOVA/Tukey tests (α=0.05). RESULTS: Exposure to all of the cements tested significantly reduced the cell viability, irrespective of the activation protocol (p<0.05). The least harmful cements were CSA and U200. Total death of cells significantly increased when exposed to BSE, GCE, and MAX, especially when chemically activated (p<0.05). Characteristic apoptotic cells increased after exposure to cements, mainly for MAX, regardless of the activation mode. Chemical activation of MAX also induced necrosis. Moreover, GCE and MAX exhibited higher percentages of late apoptotic/dead cells. Chromatograms revealed 28 compounds released from the cements tested, some of them with known carcinogenic effects. Selection of self-adhesive cements and polymerization protocols affect the cytotoxicity and cell viability of odontoblastic cells. CLINICAL SIGNIFICANCE: Despite the simplified cementation protocol, care is needed when cementing indirect restorations with self-adhesive cements, especially on recently exposed dentin. This category of material may cause differential cytotoxic effects and should be considered when selecting a cement. This is particularly true in clinical cases of light attenuation, where the polymerization depends on chemical activation, inducing higher cytotoxic damages when using some of the cements tested.

Cultura de fibroblastos dérmicos humanos na presença de ácido hialurônico e polietilenoglicol: efeitos na proliferação celular, produção de colágeno e enzimas relacionadas à remodelação da matriz extracelular / Culture of human dermal fibroblasts in the presence of hyaluronic acid and polyethylene glycol: effects on cell proliferation, collagen production, and related enzymes linked to the remodeling of the extracellular matrix

Introdução: Os preenchimentos cutâneos representam procedimentos comuns na dermatologia atual, sendo a maioria realizada com ácido hialurônico isolado ou associado a outras substâncias. Objetivo: Estudar os efeitos da adição de ácido hialurônico e polietilenoglicol a culturas de fibroblastos dérmicos humanos. Métodos: Foram avaliados: proliferação celular e produção de colágeno tipo 1 (COL1A1), na presença ou não de anticorpos antiCD44 (receptor de membrana de ácido hialurônico); síntese de metaloproteinase1 (MMP-1), fator tecidual inibidor de metaloproteinase1 (TIMP-1) e fator transformador de crescimento ß (TGF-ß), pela análise da expressão gênica via PCR (polymerase chain reaction); proliferação celular através da detecção da incorporação de um análogo da timidina no DNA celular. Resultados: Observou-se aumento na proliferação dos fibroblastos, bem como da síntese de colágeno nas culturas expostas ao ácido hialurônico, inibido parcialmente pela presença dos anticorpos antiCD44 nas culturas. A exposição das culturas ao ácido hialurônico aumenta a produção de TIMP-1 e TGF-ß e reduz a expressão de MMP-1. Esses efeitos não foram notados nas culturas expostas ao polietilenoglicol. Conclusão: In vitro, a adição de ácido hialurônico a culturas de fibroblastos dérmicos humanos aumenta a proliferação e síntese de COL1A1,TIMP-1 e TGF-ß, diminuindo a de MMP-1.A adição de antiCD44 às culturas reduz a proliferação celular e síntese de colágeno, podendo indicar o papel desse receptor na mediação desses eventos.

Introduction: Cutaneous fillings are a common procedure in today's dermatology, with the majority being carried out with hyaluronic acid isolated or combined with other substances. Objective: To study the effects of adding hyaluronic acid and polyethylene glycol to cultures of human dermal fibroblasts. Methods: The study evaluated: cell proliferation and production of type 1 collagen (COL1A1) in the presence or absence of anti-CD44 antibodies (membrane receptor for hyaluronic acid); the synthesis of metalloproteinase-1 (mmp-1), of tissue factor inhibitor of metalloproteinase-1 (TIMP - 1) and of transforming growth factor-α (TGF-α) through the analysis of gene expression via PCR (polymerase chain reaction); cell proliferation through the detection of the incorporation of a thymidine analogue in the cellular DNA. Results: Increased proliferation of fibroblasts and collagen synthesis were observed in the cultures exposed to hyaluronic acid, partially inhibited by the presence of anti-CD44 antibodies in the cultures. The exposure of cultures to hyaluronic acid enhances the production of TIMP-1 and TGF - α, and reduces the expression of MMP-1. These effects were not noticed in the cultures exposed to polyethyene glycol. Conclusion: In an in vitro setting, the addition of hyaluronic acid to cultures of human dermal fibroblasts increases proliferation and synthesis of COL1A1, TIMP-1 and TGF-α, decreasing that of MMP-1. The addition of anti-CD44 to the cultures reduces cell proliferation and collagen synthesis, which may indicate the role of that receptor in mediating those events.