RESUMO

This study investigated the incorporation of sources of calcium, phosphate, or both into electrospun scaffolds and evaluated their bioactivity on human dental pulp cells (HDPCs). Additionally, scaffolds incorporated with calcium hydroxide (CH) were characterized for degradation, calcium release, and odontogenic differentiation by HDPCs. Polycaprolactone (PCL) was electrospun with or without 0.5% w/v of calcium hydroxide (PCL + CH), nano-hydroxyapatite (PCL + nHA), or ß-glycerophosphate (PCL + ßGP). SEM/EDS analysis confirmed fibrillar morphology and particle incorporation. HDPCs were cultured on the scaffolds to assess cell viability, adhesion, spreading, and mineralized matrix formation. PCL + CH was also evaluated for gene expression of odontogenic markers (RT-qPCR). Data were submitted to ANOVA and Student's t-test (α = 5%). Added CH increased fiber diameter and interfibrillar spacing, whereas ßGP decreased both. PCL + CH and PCL + nHA improved HDPC viability, adhesion, and proliferation. Mineralization was increased eightfold with PCL + CH. Scaffolds containing CH gradually degraded over six months, with calcium release within the first 140 days. CH incorporation upregulated DSPP and DMP1 expression after 7 and 14 days. In conclusion, CH- and nHA-laden PCL fiber scaffolds were cytocompatible and promoted HDPC adhesion, proliferation, and mineralized matrix deposition. PCL + CH scaffolds exhibit a slow degradation profile, providing sustained calcium release and stimulating HDPCs to upregulate odontogenesis marker genes.

RESUMO

In vitro models of the dental pulp microenvironment have been proposed for the assessment of biomaterials, to minimise animal use in operative dentistry. In this study, a scaffold/3-D dental pulp cell culture interface was created in a microchip, under simulated dental pulp pressure, to evaluate the cell-homing potential of a chitosan (CH) scaffold functionalised with calcium aluminate (the 'CHAlCa scaffold'). This microphysiological platform was cultured at a pressure of 15 cm H2O for up to 14 days; cell viability, migration and odontoblastic differentiation were then assessed. The CHAlCa scaffold exhibited intense chemotactic potential, causing cells to migrate from the 3-D culture to its surface, followed by infiltration into the macroporous structure of the scaffold. By contrast, the cells in the presence of the non-functionalised chitosan scaffold showed low cell migration and no cell infiltration. CHAlCa scaffold bioactivity was confirmed in dentin sialophosphoprotein-positive migrating cells, and odontoblastic markers were upregulated in 3-D culture. Finally, in situ mineralised matrix deposition by the cells was confirmed in an Alizarin Red-based assay, in which the CHAlCa and CH scaffolds were adapted to fit within dentin discs. More intense deposition of matrix was observed with the CHAlCa scaffold, as compared to the CH scaffold. In summary, we present an in vitro platform that provides a simple and reproducible model for selecting and developing innovative biomaterials through the assessment of their cell-homing potential. By using this platform, it was shown that the combination of calcium aluminate and chitosan has potential as an inductive biomaterial that can mediate dentin tissue regeneration during cell-homing therapies.

Assuntos

RESUMO

STATEMENT OF PROBLEM: Based upon ethical questions and because of the difficulty of obtaining intact human teeth, researchers have used bovine teeth to assess the physical and mechanical properties of different dental materials. However, data from transdentinal cytotoxicity tests showing that the bovine dentin barrier is similar to the human dentin barrier is lacking. PURPOSE: The purpose of this in vitro study was to evaluate whether the bovine dentin barrier produces similar results to those obtained when the human dentin barrier is used to assess the transdentinal cytotoxicity of resin luting cements. MATERIAL AND METHODS: The number and diameter of dentinal tubules present in the human dentin barrier and bovine dentin barrier were evaluated and assessed with a t test (α=.05). After inserting the standardized dentin barriers into artificial pulp chambers, murine dental papilla-derived cells (MDPC-23) were seeded on the pulpal surface of the specimens, and the luting cements were applied to their occlusal surfaces. Then, the following groups were established for both human and bovine dentin barriers: no treatment (negative control); Single Bond Universal; RelyX Luting 2; RelyX U200; and RelyX Ultimate. After 24 hours, the viability (alamarBlue) and morphology (scanning electron microscopy) of the cells were evaluated with a 2-way analysis of variance and the Tukey honest significance test (α=.05). RESULTS: Dentinal tubules with larger diameters were observed in bovine dentin (P<.05), but the number of tubules was similar (P>.05). A reduction in viability and notable changes in the morphology of MDPC-23 cells occurred in the Single Bond Universal and RelyX Luting 2 groups in comparison with the negative control (P<.05). The RelyX U200 and RelyX Ultimate groups were statistically similar to the negative control (P>.05). No difference was found in cytotoxicity when the same luting cement was applied on human or bovine dentin barriers (P>.05). CONCLUSIONS: For transdentinal cytotoxicity tests of resin luting cements, the bovine dentin barrier proved similar results to the human dentin barrier.

Assuntos

RESUMO

BACKGROUND: Simulating a bacterial-induced pulpitis environment in vitro may contribute to exploring mechanisms and bioactive molecules to counteract these adverse effects. OBJECTIVE: To investigate the chronic exposure of human dental pulp cells (HDPCs) to lipopolysaccharides (LPS) aiming to establish a cell culture protocol to simulate the impaired odontogenic potential under pulpitis conditions. METHODOLOGY: HDPCs were isolated from four healthy molars of different donors and seeded in culture plates in a growth medium. After 24 h, the medium was changed to an odontogenic differentiation medium (DM) supplemented or not with E. coli LPS (0 - control, 0.1, 1, or 10 µg/mL) (n=8). The medium was renewed every two days for up to seven days, then replaced with LPS-free DM for up to 21 days. The activation of NF-κB and F-actin expression were assessed (immunofluorescence) after one and seven days. On day 7, cells were evaluated for both the gene expression (RT-qPCR) of odontogenic markers (COL1A1, ALPL, DSPP, and DMP1) and cytokines (TNF, IL1B, IL8, and IL6) and the production of reactive nitrogen (Griess) and oxygen species (Carboxy-H2DCFDA). Cell viability (alamarBlue) was evaluated weekly, and mineralization was assessed (Alizarin Red) at 14 and 21 days. Data were analyzed with ANOVA and post-hoc tests (α=5%). RESULTS: After one and seven days of exposure to LPS, NF-κB was activated in a dose-dependent fashion. LPS at 1 and 10 µg/mL concentrations down-regulated the gene expression of odontogenic markers and up-regulated cytokines. LPS at 10 µg/mL increased both the production of reactive nitrogen and oxygen species. LPS decreased cell viability seven days after the end of exposure. LPS at 1 and 10 µg/mL decreased hDPCs mineralization in a dose-dependent fashion. CONCLUSION: The exposure to 10 µg/mL LPS for seven days creates an inflammatory environment that is able to impair by more than half the odontogenic potential of HDPCs in vitro, simulating a pulpitis-like condition.

Assuntos

RESUMO

OBJECTIVE: Evaluate the influence of a polymeric catalyst primer (PCP) on esthetic efficacy (EE), degradation kinetics of hydrogen peroxide (H2 O2 ), and trans-amelodentinal cytotoxicity (TC) of bleaching gels. MATERIALS AND METHODS: The following groups were established: G1: No treatment (NC, negative control); G2: PCP; G3: 10% H2 O2 ; G4: PCP + 10% H2 O2 ; G5: 20% H2 O2 ; G6: PCP + 20% H2 O2 ; G7: 35% H2 O2 (positive control); G8: PCP + 35% H2 O2 . To determine EE, enamel/dentin discs (E/DDs) were stained and subjected or not to bleaching protocols for 45 min. To assess TC, the E/DDs were adapted to artificial pulp chambers. The extracts (culture medium + gel components diffused through E/DDs) were applied to odontoblast-like MDPC-23 cells. The viability (VB), oxidative stress (OxS), morphology (SEM), amount of H2 O2 diffused and the production of hydroxyl radical (OH• ) were assessed (two-way ANOVA/Tukey/paired Student t-test; p < 0.05). RESULTS: The highest EE was found in G8 (p < 0.05), and G4, G6, and G7 did not differ statistically (p > 0.05). In G4, the limited H2 O2 diffusion reduced OxS and increased cell VB (p < 0.05). CONCLUSIONS: Coating the enamel with PCP containing 10 mg/ml of manganese oxide before applying the 10% H2 O2 bleaching gel maintains the EE of conventional in-office bleaching and minimizes the toxic effects of this esthetic therapy. CLINICAL SIGNIFICANCE: Coating the enamel with a PCP before applying the bleaching gel may potentiate the EE of the conventional in-office tooth bleaching and reduce the toxicity of this professional therapy to the dental pulp.

Assuntos

RESUMO

Abstract Simulating a bacterial-induced pulpitis environment in vitro may contribute to exploring mechanisms and bioactive molecules to counteract these adverse effects. Objective To investigate the chronic exposure of human dental pulp cells (HDPCs) to lipopolysaccharides (LPS) aiming to establish a cell culture protocol to simulate the impaired odontogenic potential under pulpitis conditions. Methodology HDPCs were isolated from four healthy molars of different donors and seeded in culture plates in a growth medium. After 24 h, the medium was changed to an odontogenic differentiation medium (DM) supplemented or not with E. coli LPS (0 - control, 0.1, 1, or 10 µg/mL) (n=8). The medium was renewed every two days for up to seven days, then replaced with LPS-free DM for up to 21 days. The activation of NF-κB and F-actin expression were assessed (immunofluorescence) after one and seven days. On day 7, cells were evaluated for both the gene expression (RT-qPCR) of odontogenic markers (COL1A1, ALPL, DSPP, and DMP1) and cytokines (TNF, IL1B, IL8, and IL6) and the production of reactive nitrogen (Griess) and oxygen species (Carboxy-H2DCFDA). Cell viability (alamarBlue) was evaluated weekly, and mineralization was assessed (Alizarin Red) at 14 and 21 days. Data were analyzed with ANOVA and post-hoc tests (α=5%). Results After one and seven days of exposure to LPS, NF-κB was activated in a dose-dependent fashion. LPS at 1 and 10 µg/mL concentrations down-regulated the gene expression of odontogenic markers and up-regulated cytokines. LPS at 10 µg/mL increased both the production of reactive nitrogen and oxygen species. LPS decreased cell viability seven days after the end of exposure. LPS at 1 and 10 µg/mL decreased hDPCs mineralization in a dose-dependent fashion. Conclusion The exposure to 10 µg/mL LPS for seven days creates an inflammatory environment that is able to impair by more than half the odontogenic potential of HDPCs in vitro, simulating a pulpitis-like condition.

RESUMO

OBJECTIVE: To assess the influence of coating the enamel with a nanofiber scaffold (NS) and a polymeric catalyst primer (PCP) on the esthetic efficacy, degradation kinetics of hydrogen peroxide (H2O2), and trans-amelodentinal cytotoxicity of bleaching gels subjected or not to violet-LED irradiation. METHODOLOGY: The following groups were established (n = 8): G1- No treatment (negative control); G2- NS+PCP; G3- LED; G4- NS+PCP+LED; G5- 35% H2O2 (positive control); G6- NS+PCP+35% H2O2+LED; G7- 20% H2O2; G8- NS+PCP+20% H2O2+LED; G9- 10% H2O2; G10- NS+PCP+10% H2O2+LED. For esthetic efficacy analysis, enamel/dentin discs were stained and exposed for 45 min to the bleaching protocols. To assess the cytotoxicity, the stained enamel/dentin discs were adapted to artificial pulp chambers, and the extracts (culture medium + components diffused through the discs) were collected and applied to MDPC-23 cells, which had their viability, oxidative stress, and morphology (SEM) evaluated. The amount of H2O2 diffused and hydroxyl radical (OH•) production were also determined (two-way ANOVA/Tukey/paired Student t-test; p < 0.05). RESULTS: G6 had the highest esthetic efficacy compared to the other groups (p < 0.05). Besides the esthetic efficacy similar to conventional in-office bleaching (G5; p > 0.05), G10 also showed the lowest toxic effect and oxidative stress to MDPC-23 cells compared to all bleached groups (p < 0.05). CONCLUSION: Coating the enamel with a nanofiber scaffold and a polymeric catalyst primer, followed by the application of 10%, 20%, or 35% H2O2 bleaching gels irradiated with a violet LED, stimulates H2O2 degradation, increasing esthetic efficacy and reducing the trans-amelodentinal toxicity of the treatment.

Assuntos

RESUMO

This paper aimed to assess the influence of adhesive restoration interface on the diffusion of hydrogen peroxide (H2O2), indirect toxicity, and pro-inflammatory mediators expression by odontoblast-like cells, after in-office tooth whitening. Dental cavities prepared in bovine enamel/dentin discs were adhesively restored and subjected or not to hydrolytic degradation (HD). A whitening gel with 35% H2O2 (WG) was applied for 45 min onto restored and non-restored specimens adapted to artificial pulp chambers giving rise to the groups: SD- intact discs (control); SD/HP- whitened intact discs; RT/HP- restored and whitened discs; and RT/HD/HP- restored and whitened discs subjected to HD. The extracts (culture medium + WG components diffused through enamel/dentin/restoration interface) were collected and applied to odontoblast-like MDPC-23 cells. The study evaluated the amount of H2O2 in the extracts, as well as the cell viability (CV), cell morphology (CM), and gene expression of inflammatory mediators (TNF-α and COX-2) by the pulp cells exposed to the extracts (ANOVA and Tukey tests; 5% significance). All whitened groups presented lower CV than SD (control; p<0.05). The highest CV reduction and gene expression of TNF-α and COX-2 was observed in the RT/HD/HP group in comparison with SD/HP and RT/HP (control; p<0.05). CM alterations occurred in all whitened groups. The intensity of these cell side effects was directly related with the amount of H2O2 in the extracts. We concluded that adhesive restoration of dental cavity increases the H2O2 diffusion after in-office whitening, enhancing the indirect toxicity of this therapy and trigger pro-inflammatory overexpression by MDPC-23 cells.

Assuntos

RESUMO

OBJECTIVES: To investigate the transdentinal cytotoxicity (TC), degree of conversion (DC), and micro shear bond strength (µSBS) to dentin of light-cured resin cements (LCRCs) photoactivated directly or through a ceramic veneer( ± CV). MATERIALS AND METHODS: The TC was assessed using human dentin discs adapted into artificial pulp chambers. Odontoblast-like cells were seeded on the pulp surface of the discs, then three LCRCs( ± CV) were applied on their etched and hybridized occlusal surface (n = 8/group). The adhesive systems of each LCRCs and sterile phosphate-buffered saline were used as positive and negative controls, respectively. After 24 h, the viability and morphology of cells adhered on discs were assessed. The extracts (culture medium + components of the materials diffused through the discs) were applied on the MDPC-23 to evaluate their viability, adhesion/spreading (A/S), alkaline phosphatase activity (ALP), and mineralized nodule formation (MN). LCRCs( ± CV) specimens were evaluated concerning the DC and µSBS to dentin. Data were analyzed by one-, two-, or three-way ANOVA/Dunnett, Sidak, and Games-Howell tests (α = 5%). RESULTS: All LCRCs( ± CV) reduced cell viability, A/S, ALP, MN, and DC. Except for µSBS, the intensity of reduction was dependent on the LCRC used. LCRCs+CV resulted in lower DC and µSBS but did not increase the TC. SIGNIFICANCE: Besides the presence of CV between the light source and LCRCs reduces the degree of conversion and bond strength to dentin, these materials cause variable level of transdentinal toxicity to pulp cells. Thus, the composition and curing protocols of LCRCs should be revisited and reinforced to prevent mechanical and biological drawbacks.

Assuntos

RESUMO

Abstract This paper aimed to assess the influence of adhesive restoration interface on the diffusion of hydrogen peroxide (H2O2), indirect toxicity, and pro-inflammatory mediators expression by odontoblast-like cells, after in-office tooth whitening. Dental cavities prepared in bovine enamel/dentin discs were adhesively restored and subjected or not to hydrolytic degradation (HD). A whitening gel with 35% H2O2 (WG) was applied for 45 min onto restored and non-restored specimens adapted to artificial pulp chambers giving rise to the groups: SD- intact discs (control); SD/HP- whitened intact discs; RT/HP- restored and whitened discs; and RT/HD/HP- restored and whitened discs subjected to HD. The extracts (culture medium + WG components diffused through enamel/dentin/restoration interface) were collected and applied to odontoblast-like MDPC-23 cells. The study evaluated the amount of H2O2 in the extracts, as well as the cell viability (CV), cell morphology (CM), and gene expression of inflammatory mediators (TNF-α and COX-2) by the pulp cells exposed to the extracts (ANOVA and Tukey tests; 5% significance). All whitened groups presented lower CV than SD (control; p<0.05). The highest CV reduction and gene expression of TNF-α and COX-2 was observed in the RT/HD/HP group in comparison with SD/HP and RT/HP (control; p<0.05). CM alterations occurred in all whitened groups. The intensity of these cell side effects was directly related with the amount of H2O2 in the extracts. We concluded that adhesive restoration of dental cavity increases the H2O2 diffusion after in-office whitening, enhancing the indirect toxicity of this therapy and trigger pro-inflammatory overexpression by MDPC-23 cells.

Resumo Este trabalho teve como objetivo avaliar a influência da interface de uma restauração adesiva na difusão do peróxido de hidrogênio (H2O2), toxicidade indireta e expressão de mediadores pró-inflamatórios por células odontoblastóides, após clareamento dental em consultório. Cavidades dentárias preparadas em discos de esmalte / dentina foram restauradas com adesivo e submetidas ou não à degradação hidrolítica (HD). Um gel clareador com 35% H2O2 (WG) foi aplicado por 45 min em discos restaurados e não restaurados adaptados às câmaras pulpares artificiais dando origem aos grupos: SD- discos intactos (controle); SD / HP - Discos intactos clareados; RT / HP - discos restaurados e clareados; e RT / HD / HP - discos restaurados, clareados e submetidos a HD. Os extratos (meio de cultura + componentes WG difundidos através da interface esmalte/dentina/restauração) foram coletados e aplicados em células odontoblastóides MDPC-23. Foi avaliada a quantidade de H2O2 nos extratos, bem como a viabilidade (CV), morfologia (CM) e expressão gênica de mediadores inflamatórios (TNF-α e COX-2) pelas células pulpares expostas aos extratos (ANOVA e testes de Tukey; 5% de significância). Todos os grupos clareados apresentaram menor CV do que SD (controle; p <0,05). A maior redução CV e expressão gênica de TNF-α e COX-2 foi observada no grupo RT / HD / HP em comparação com SD / HP e RT / HP (controle; p <0,05). Alterações na CM ocorreram em todos os grupos clareados. A intensidade desses efeitos celulares teve relação direta com a quantidade de H2O2 nos extratos. Concluímos que a presença de uma cavidade contendo restauração adesiva aumenta a difusão de H2O2 após o clareamento em consultório, o que, por sua vez, aumenta a toxicidade indireta dessa terapia e desencadeia a expressão de mediadores pró-inflamatórios pelas células pulpares MDPC-23.

RESUMO

OBJECTIVES: Evaluate in vitro the esthetic efficacy and cytotoxicity of a bleaching gel containing 35% hydrogen peroxide (BG-35%H2O2), applied for different time intervals, on enamel coated or not with polymeric biomaterials. MATERIALS AND METHODS: Nanofiber scaffolds (NSc) and a primer catalyst (PrCa) were used to coat the bovine enamel/dentin discs before the application of BG-35%H2O2, according to the following groups: G1-negative control (NC, without treatment); G2, G3, and G4-BG-35%H2O2 applied for 3 × 15, 2 × 15, and 15 min; G5, G6, and G7-BG-35%H2O2 applied on enamel coated with NSc and PrCa for 3 × 15; 2 × 15, and 15 min, respectively. The culture medium with components of gel diffused through the discs was applied on MDPC-23 cells, which were evaluated regarding to viability (VB), integrity of the membrane (IM), and oxidative stress (OxS). The quantity of H2O2 diffused and esthetic efficacy (ΔE/ΔWI) of the dental tissues were also analyzed (ANOVA/Tukey; p < 0.05). RESULTS: Only G7 was similar to G1 regarding VB (p > 0.05). The lowest value of H2O2 diffusion occurred in G4 and G7, where the cells exhibited the lowest OxS than G2 (p < 0.05). Despite G5 showing the greatest ΔE regarding other groups (p < 0.05), the esthetic efficacy observed in G7 was similar to G2 (p > 0.05). ΔWI indicated a greater bleaching effect for groups G5, G6, and G7 (p < 0.05). CONCLUSION: Coating the dental enamel with polymeric biomaterials reduced the time and the cytotoxicity of BG-35%H2O2. CLINICAL SIGNIFICANCE: Coating the dental enamel with polymeric biomaterials allows safer and faster BG-35%H2O2 application.

Assuntos

RESUMO

OBJECTIVES: The aim of this study was to characterize polycaprolactone-based nanofiber scaffolds (PCL) incorporated with calcium hydroxide (CH) and evaluate their bioactivity on human dental pulp cells (HDPCs) when loaded with fibronectin (FN). MATERIALS AND METHODS: CH (0.1%; 0.2%; 0.4% w/v; or 0%) was incorporated into PCL (10% w/v) scaffolds prepared by electrospinning. Morphology and composition were characterized using SEM/EDS. HDPCs were seeded on the scaffolds and evaluated for viability (alamarBlue; Live/Dead), and adhesion/spreading (F-actin). Next, scaffolds containing 0.4% CH were loaded with FN (20 µg/mL). HDPCs were evaluated for viability, adhesion/spreading, migration (Trans-well), gene expression (RT-qPCR), alkaline phosphatase activity (ALP), and mineralization nodules (Alizarin Red). Data were submitted to ANOVA and post-hoc tests (α = 5%). RESULTS: Nanofibers with larger diameter were seen as CH concentration increased, while there was no effect on interfibrillar spaces. An increase in cell viability was seen for 0.4% CH, in all periods. Incorporation of CH and FN into the scaffolds increased cellular migration, spread, and viability, all intensified when CH and FN were combined. ALPL and DSPP expression, and ALP activity were not affected by CH and FN. COL1A1 was downregulated in all groups, while DMP1 was upregulated in the presence of CH, with no differences for the groups loaded with FN. CH increased the formation of mineralized matrix, which was not influenced by FN. CONCLUSIONS: In conclusion, the incorporation of CH enhanced the odontogenic potential of HDPCs, irrespective of the presence of FN. The PCL + 0.4% CH formulation may be a useful strategy for use in dentin tissue engineering. CLINICAL RELEVANCE: A change in the form of presentation of calcium hydroxide-based materials used for direct pulp capping can increase biocompatibility and prolong the vitality of dental pulp.

Assuntos

RESUMO

Background Decompressive craniectomy is a consolidated method for the treatment of malignant ischemic stroke (iS) in the territory of the middle cerebral artery. Thus, factors contributing to mortality constitute an important area of investigation. Objective To evaluate the epidemiological clinical profile and predictors of mortality in a single-center population of patients undergoing decompressive craniectomy for the treatment of malignant iS. Methods A single-center retrospective study was performed in 87 patients with malignant iS subjected to emergency decompressive craniectomy from January 2014 to December 2017. Age, gender, laterality, aphasia, time interval between disease onset and treatment, and clinical and neurological outcomes using the Glasgow coma scale were assessed. The patients were stratified by age: a group of participants 60 years old or younger, and a group of participants older than 60 years old for assessment of survival and mortality by the Kaplan-Meier test and log-rank comparison. The intensity of the association between demographic and clinical variables was evaluated by multivariate Cox regression. Results Ischemic stroke was prevalent in patients with hypertension (63.29%). Seventy seven (84%) patients had some type of postoperative complication, mostly pneumonia (42.8%). The risk of death was 2.71 (p » 0.0041) and 1.93 (p » 0.0411) times higher in patients older than 60 and with less than 8 points on the Glasgow coma scale, respectively. Conclusion Malignant iS has a significant mortality rate. Age above 60 years and Glasgow coma scale values below 8 were statistically correlated with unfavorable prognosis.

Contexto A craniectomia descompressiva é um método consolidado para o tratamento do acidente vascular cerebral isquêmico (AVCI) maligno no território da artéria cerebral média. No entanto, os fatores envolvidos na mortalidade constituem objeto de investigação. Objetivo Avaliar o perfil clínico epidemiológico e os preditores de mortalidade em uma população unicêntrica de pacientes submetidos à craniectomia descompressiva para tratamento de acidente vascular isquêmico maligno. Métodos Um estudo retrospectivo unicêntrico foi realizado com 87 pacientes com AVCI maligno submetidos à craniectomia descompressiva de emergência de janeiro de 2014 a dezembro de 2017. Idade, gênero, lateralidade, afasia, intervalo de tempo entre o início da doença e o tratamento, e escala de coma de Glasgow foram avaliados. Os pacientes foram estratificados por idade: um grupo com participantes com 60 anos de idade ou menos, e outro com participantes com mais de 60 anos para avaliação de sobrevida e mortalidade pelo teste de Kaplan-Meier e comparação log-rank. A intensidade da associação entre variáveis demográficas e clínicas foi avaliada por regressão multivariada de Cox. Resultados Houve prevalência de hipertensos (63,29%). Setenta e sete (84%) dos pacientes tiveram algum tipo de complicação pós-operatória, com predomínio de pneumonia (42,8%). O risco de morte foi 2,71 e 1,93 maior em pacientes com mais de 60 anos e com menos de 8 pontos na escala de coma de Glasgow, respectivamente. Conclusão O AVCI maligno ainda tem uma taxa de mortalidade significativa. Idade acima de 60 anos e valores da escala de coma de Glasgow abaixo de 8 foram estatisticamente correlacionados com um prognóstico desfavorável.

RESUMO

The current study evaluated the effects of taxifolin treatments on the viability of osteoblast-like cells, and on the expression of early mineralization markers, as part of the ongoing search for new endodontic materials able to induce periapical healing without causing cytotoxicity. Saos-2 osteoblast-like cells were exposed to different concentrations of taxifolin (5 and 10 µM), applied as pretreatments either for 24h and 72h, or continuously throughout the experimental protocol. Cell viability using the methylthiazole tetrazolium (MTT) assay, alkaline phosphatase activity using thymolphthalein monophosphate assays, deposition of mineralized nodules using alizarin red staining, and expression of ALP and COL-1 by qPCR were determined after 6 and 13 days of treatment. The data were analyzed statistically (p<0.05). Taxifolin was not cytotoxic in the concentrations tested. Pretreatments with taxifolin for 24h and 72h at 10 µM stimulated ALP activity, and increased mineralized nodule deposition by Saos-2 cells. Continuous treatment with taxifolin was not effective in stimulating ALP activity and mineralization. ALP and COL-1 gene expression increased with taxifolin pretreatments, since the highest mRNA levels were observed after 72h of pretreatment with taxifolin at 10 µM on day 13. In conclusion, taxifolin was cytocompatible, and induced mineralization markers when applied for short periods in osteoblast-like cell culture.

Assuntos

RESUMO

BACKGROUND: Potent signaling agents stimulate and guide pulp tissue regeneration, especially in endodontic treatment of teeth with incomplete root formation. OBJECTIVE: This study evaluated the bioactive properties of low concentrations of extracellular matrix proteins on human apical papilla cells (hAPCs). METHODOLOGY: Different concentrations (1, 5, and 10 µg/mL) of fibronectin (FN), laminin (LM), and type I collagen (COL) were applied to the bottom of non-treated wells of sterilized 96-well plates. Non-treated and pre-treated wells were used as negative (NC) and positive (PC) controls. After seeding the hAPCs (5×103 cells/well) on the different substrates, we assessed the following parameters: adhesion, proliferation, spreading, total collagen/type I collagen synthesis and gene expression (ITGA5, ITGAV, COL1A1, COL3A1) (ANOVA/Tukey; α=0.05). RESULTS: We observed greater attachment potential for cells on the FN substrate, with the effect depending on concentration. Concentrations of 5 and 10 µg/mL of FN yielded the highest cell proliferation, spreading and collagen synthesis values with 10 µg/mL concentration increasing the ITGA5, ITGAV, and COL1A1 expression compared with PC. LM (5 and 10 µg/mL) showed higher bioactivity values than NC, but those were lower than PC, and COL showed no bioactivity at all. CONCLUSION: We conclude that FN at 10 µg/mL concentration exerted the most intense bioactive effects on hAPCs.

Assuntos

RESUMO

Evaluate the kinetics of hydrogen peroxide (H2 O2 ) degradation, esthetic efficacy and cytotoxicity of a bleaching gel with 35%H2 O2 applied on enamel previously covered or not with polymeric nanofibrillar scaffold (SNan), polymeric primer catalyst (PPol), and both. Standardized enamel/dentin discs (n = 128) obtained from bovine teeth were adapted to pulp chambers. After covering enamel with the polymeric products, the bleaching gel was applied for 45 min, establishing the following groups: G1: no treatment (negative control); G2: 35%H2 O2 (positive control); G3: SNan; G4: PPol; G5: SNan + PPol; G6: SNan + 35%H2 O2 ; G7: PPol + 35%H2 O2 ; G8: SNan + PPol + 35%H2 O2 . The kinetics of H2 O2 degradation (n = 8), bleaching efficacy (ΔE/ΔWI; n = 8), trans-amelodentinal cytotoxicity (n = 8), and cell morphology (n = 4) were assessed (ANOVA/Tukey test; p < 0.05). Greater H2 O2 degradation occurred in G7 and G8. Bleaching efficacy (ΔE) was higher in G6, G7, and G8 in comparison with G2 (p < 0.05). However, no difference was observed for ΔWI (p > 0.05). G8 presented the lower level of trans-amelodentinal diffusion of H2 O2 , oxidative stress, and toxicity to the MDPC-23 cells (p < 0.05). Polymeric biomaterials increased the kinetics of H2 O2 decomposition, as well as maintained the esthetic efficacy and minimized the cytotoxicity caused by a bleaching gel with 35%H2 O2 . CLINICAL SIGNIFICANCE: Application of a bleaching gel with 35%H2 O2 on enamel previously covered by polymeric biomaterials maintains the esthetic efficacy and reduces the cytotoxicity caused by a single session of in-office dental bleaching.

Assuntos

RESUMO

INTRODUCTION: Guided tissue regeneration has been considered a promising biological strategy to replace conventional endodontic therapies of teeth with incomplete root formation. Therefore, in the present study, a collagen/gelatin hydrogel either containing dosages of fibronectin (FN), or not, was developed and assessed concerning their bioactive and chemotactic potential on human apical papilla cells (hAPCs). METHODS: Hydrogels were prepared by varying the ratio of collagen and gelatin (Col/Gel; v/v), and used to establish the following groups: Collagen (positive control); Col/Gel 4:6; Col/Gel 6:4; Col/Gel 8:2. The viability, adhesion, and spreading of cells seeded on the hydrogels were evaluated. Different concentrations of FN (0, 5, or 10 µg/mL) were incorporated into the best formulation of the collagen/gelatin hydrogel selected. Then, the hAPCs seeded on the biomaterials were assessed concerning the cell migration, viability, adhesion and spreading, and gene expression of ITGA5, ITGAV, COL1A1, and COL3A1. RESULTS: The Col/Gel 8:2 group exhibited better cell viability, adhesion and spreading in comparison with Control. Higher values of hAPC migration, viability, adhesion, spreading and gene expression of pulp regeneration markers were found, the higher the concentration was of FN incorporated into the collagen/gelatin hydrogel. CONCLUSION: Collagen/gelatin hydrogel with 10 µg/mL of FN had potent bioactive and chemotactic effects on cultured hAPCs.

Assuntos

RESUMO

Fibronectin (FN)-loaded nanofiber scaffolds were developed and assessed concerning their bioactive potential on human apical papilla cells (hAPCs). First, random (NR) and aligned (NA) nanofiber scaffolds of polycaprolactone (PCL) were obtained by electrospinning technique and their biological properties were evaluated. The best formulations of NR and NA were loaded with 0, 5, or 10 µg/ml of FN and their bioactivity was assessed. Finally, FN-loaded NR and NA tubular scaffolds were prepared and their chemotactic potential was analyzed using an in vitro model to mimic the pulp regeneration of teeth with incomplete root formation. All scaffolds tested were cytocompatible. However, NR and NA based on 10% PCL promoted the highest hAPCs proliferation, adhesion and spreading. Polygonal and elongated cells were observed on NR and NA, respectively. The higher the concentration of FN added to the scaffolds, greater cell migration, viability, proliferation, adhesion and spreading, as well as collagen synthesis and gene expression (ITGA5, ITGAV, COL1A1, COL3A1). In addition, tubular scaffolds with NA loaded with FN (10 µg/ml) showed the highest chemotactic potential on hAPCs. It was concluded that FN-loaded NA scaffolds may be an interesting biomaterial to promote hAPCs-mediated pulp regeneration of endodontically compromised teeth with incomplete root formation.

Assuntos

RESUMO

Abstract Potent signaling agents stimulate and guide pulp tissue regeneration, especially in endodontic treatment of teeth with incomplete root formation. Objective This study evaluated the bioactive properties of low concentrations of extracellular matrix proteins on human apical papilla cells (hAPCs). Methodology Different concentrations (1, 5, and 10 µg/mL) of fibronectin (FN), laminin (LM), and type I collagen (COL) were applied to the bottom of non-treated wells of sterilized 96-well plates. Non-treated and pre-treated wells were used as negative (NC) and positive (PC) controls. After seeding the hAPCs (5×103 cells/well) on the different substrates, we assessed the following parameters: adhesion, proliferation, spreading, total collagen/type I collagen synthesis and gene expression (ITGA5, ITGAV, COL1A1, COL3A1) (ANOVA/Tukey; α=0.05). Results We observed greater attachment potential for cells on the FN substrate, with the effect depending on concentration. Concentrations of 5 and 10 µg/mL of FN yielded the highest cell proliferation, spreading and collagen synthesis values with 10 µg/mL concentration increasing the ITGA5, ITGAV, and COL1A1 expression compared with PC. LM (5 and 10 µg/mL) showed higher bioactivity values than NC, but those were lower than PC, and COL showed no bioactivity at all. Conclusion We conclude that FN at 10 µg/mL concentration exerted the most intense bioactive effects on hAPCs.

Assuntos

RESUMO

OBJECTIVES: This study aimed to develop a porous chitosan-calcium-aluminate scaffold (CH-AlCa) in combination with a bioactive dosage of 1α,25-dihydroxyvitamin D3 (1α,25VD), to be used as a bioactive substrate capable to increase the odontogenic potential of human dental pulp cells (HDPCs). MATERIALS AND METHODS: The porous CH-AlCa was developed by the incorporation of an AlCa suspension into a CH solution under vigorous agitation, followed by phase separation at low temperature. Scaffold architecture, porosity, and calcium release were evaluated. Thereafter, the synergistic potential of CH-AlCa and 1 nM 1α,25VD, selected by a dose-response assay, for HDPCs seeded onto the materials was assessed. RESULTS: The CH-AlCa featured an organized and interconnected pore network, with increased porosity in comparison with that of plain chitosan scaffolds (CH). Increased odontoblastic phenotype expression on the human dental pulp cell (HDPC)/CH and HDPC/CH-AlCa constructs in the presence of 1 nM 1α,25VD was detected, since alkaline phosphatase activity, mineralized matrix deposition, dentin sialophosphoprotein/dentin matrix acidic phosphoprotein 1 mRNA expression, and cell migration were overstimulated. This drug featured a synergistic effect with CH-AlCa, since the highest values of cell migration and odontoblastic markers expression were observed in this experimental condition. CONCLUSIONS: The experimental CH-AlCa scaffold increases the chemotaxis and regenerative potential of HDPCs, and the addition of low-dosage 1α,25VD to this scaffold enhances the potential of these cells to express an odontoblastic phenotype. CLINICAL RELEVANCE: Chitosan scaffolds enriched with calcium-aluminate in association with low dosages of 1α,25-dihydroxyvitamin D3 provide a highly bioactive microenvironment for dental pulp cells prone to dentin regeneration, thus providing potential as a cell-free tissue engineering system for direct pulp capping.

Assuntos