ABSTRACT
Abstract Objective The aim of this in vitro study was to investigate the effect of two desensitizing agents and water on hydraulic conductance in human dentin. Material and Methods GLUMA Desensitizer PowerGel (GLU) contains glutaraldehyde (GA) and 2-hydroxyethyl methacrylate (HEMA), and Teethmate Desensitizer (TD) is a powder comprising tetracalcium phosphate (TTCP) and dicalcium phosphate anhydrous (DCPA) that is mixed with water. Deionized water was used as a negative control (CTR). Thirty discs with a thickness of 1.2 mm were cut from the coronal dentin of the third molars and cleaned with 0.5 M EDTA (pH 7.4). After being mounted in a split-chamber device, the discs were pressurized with water at 1 kPa and 3 kPa in order to measure flow rates with a highly sensitive micro-flow sensor and to calculate hydraulic conductance as a baseline value (BL). Following the application of GLU, TD, and CTR (n=10), hydraulic conductance was remeasured with intermittent storage in water after 15 min, 1 d, 1 w, and 1 m. Reduction in permeability (PR%) was calculated from hydraulic conductance. Data were statistically analyzed using nonparametric methods (α<0.05). Representative discs were inspected by SEM. Results PR% for GLU and TD were 30-50% 15 min and 1 m after their application. Post hoc tests indicated that PR% of CTR was significantly greater than those of GLU and TD at all time points tested. The PR% of GLU and TD were not significantly different. SEM examinations showed noncollapsed collagen meshes at the tubular entrances after GLU, and crystalline precipitates occluding the tubular orifices after TD, whereas CTR specimens showed typical patterns of etched dentin. Conclusions The present study on hydraulic conductance in dentin discs treated with two chemically different desensitizing agents and water as a control demonstrated that both products may be characterized as effective.
Subject(s)
Humans , Calcium Phosphates/chemistry , Glutaral/chemistry , Dentin/drug effects , Dentin Permeability/drug effects , Dentin Desensitizing Agents/chemistry , Methacrylates/chemistry , Surface Properties , Time Factors , Materials Testing , Water/chemistry , Microscopy, Electron, Scanning , Random Allocation , Edetic Acid/chemistry , Statistics, NonparametricABSTRACT
El controlar la infección es una obligación profesional de fundamental importancia así como la reducción del riesgo de contaminacióncruzada durante los procedimientos clínicos para la calidad y la seguridad en la práctica dental. Material y métodos: Un total de 27 impresiones individuales fueron obtenidas de pacientes, las cuales se dividieron en tres grupos para su tratamiento. Grupo control: nueve impresiones individuales usando una silicona por adición, sin desinfectar,fueron sumergidas en agua bidestilada durante 10 minutos. Grupo A: nueve impresiones individuales fueron sumergidas en glutaraldehído al 2 por ciento durante 10 minutos. Grupo B: nueve impresiones individuales fueron esterilizadas mediante autoclave a 134 oC por 15 minutos a 15 psi. Resultados: Después de realizar el conteo bacteriano respectivo de cada grupo de estudio, se observó el crecimiento bacteriano en dosgrupos, siendo notoria la falta de crecimiento en las muestras del grupoB, mientras que en el grupo control la cuenta fue mayor que en el grupo A. Conclusiones: El lavado de la impresión reduce la cantidad de microorganismos presentes mas no la desinfecta. El glutaraldehído al 2 por ciento fue eficaz en la eliminación de microorganismos no esporulados provenientes de la cavidad oral presentes en las impresiones conmaterial elastomérico. La eliminación completa de microorganismos puede ser lograda mediante la esterilización de las impresiones con material elastomérico...
Subject(s)
Humans , Infection Control, Dental/methods , Disinfection/methods , Sterilization/methods , Dental Impression Materials/standards , Culture Media , Dental Impression Technique , Glutaral/chemistry , Hot Temperature , Mexico , Colony Count, Microbial/methods , Silicone Elastomers , Data Interpretation, StatisticalABSTRACT
OBJECTIVE: Chemical solutions have been widely used for disinfection of dentures, but their effect on color stability of denture tooth acrylic resins after repeated procedures is still unclear. The aim of this in vitro study was to evaluate whether repeated cycles of chemical disinfectants affected the color stability of two denture tooth acrylic resins. MATERIAL AND METHODS: Sixty disc-shaped specimens (40 mm x 3 mm) were fabricated from two different brands (Artiplus and Trilux) of denture tooth acrylic resin. The specimens from each brand (n=30) were randomly divided into 6 groups (n=5) and immersed in the following solutions: distilled water (control group) and 5 disinfecting solutions (1 percent sodium hypochlorite, 2 percent sodium hypochlorite, 5.25 percent sodium hypochlorite, 2 percent glutaraldehyde, and 4 percent chlorhexidine gluconate). Tooth color measurements were made by spectrophotometry. Before disinfection, the initial color of each tooth was recorded. Further color measurements were determined after subjecting the specimens to 7, 21, 30, 45, 60, and 90 immersion cycles in each tested solution. Color differences (ΔE*) were determined using the CIE L*a*b* color system. Data were analyzed using two-way repeated measures analysis of variance (ANOVA) followed by Tukey tests. The significance level was set at 5 percent. RESULTS: There were statistically significant differences in ΔE* among the 5 disinfectants and water during the 90 cycles of immersion for both denture tooth acrylic resins. Distilled water promoted the greatest color change in both denture tooth acrylic resins, nevertheless none of tested disinfectants promoted ΔE* values higher than 1.0 on these acrylic materials during the 90 cycles of disinfection. CONCLUSIONS: Repeated immersion cycles in disinfecting solutions alter ΔE* values, however these values do not compromise the color of the tested denture tooth acrylic resins because they are imperceptible to the human eye.
Subject(s)
Humans , Acrylic Resins/chemistry , Denture, Complete , Dental Disinfectants/pharmacology , Immersion , Prosthesis Coloring , Analysis of Variance , Color , Chlorhexidine/analogs & derivatives , Chlorhexidine/chemistry , Chlorhexidine/pharmacology , Dental Disinfectants/chemistry , Disinfectants/chemistry , Glutaral/chemistry , Glutaral/pharmacology , Materials Testing/methods , Random Allocation , Spectrophotometry , Sodium Hypochlorite/chemistry , Sodium Hypochlorite/pharmacology , Time FactorsABSTRACT
O presente trabalho avaliou a influência da desinfecção química na estabilidade dimensional dos moldes de alginato com o uso de glutaraldeído a 2% e hipoclorito de sódio a 1%, com o uso de técnicas de aspersão e imersão em moldes de alginato. Foi confeccionado um modelo mestre em aço inoxidável, simulando dois pilares preparados para coroa total de uma prótese parcial fixa, com pontos de referência gravados na superfície oclusal e vestibular, obtendo assim a medida das distâncias interpilares. Foram confeccionados 40 corpos de prova, divididos em 5 grupos, sendo um grupo controle e 4 grupos testes. Os resultados foram submetidos à análise de variância em 2 critérios para avaliação de qual substância desinfetante, assim como qual técnica de desinfecção, provocava a menor alteração dimensional. De acordo com os resultados, os grupos que apresentaram menores alterações foram os que passaram pela técnica de aspersão. Quanto ao tipo de material utilizado (glutaraldeído e hipoclorito de sódio), os resultados não apresentaram diferenças estatisticamente significante na estabilidade dos moldes de alginato
This study evaluated the influence of chemical disinfection in the dimensional stability of alginate impressions using glutaraldehyde, 2% and sodium hypochlorite (NaOCl), 1%, using sprinkling and immersion techniques in the irreversible hydrocolloid impression. A stainless stell master model was made simulating two pillars were made, simulating two pillars prepared for full crown of a fixed partial denture, with reference points recorded in the vestibular and occlusal surface, thus obtaining a measure of distance pillar. 40 specimens were prepared, divided into five groups, one control group and four test groups. The results were subjected to statistical analysis ANOVA 2 ways to evaluate which of disinfectant substance and which technique of disinfection, caused the least dimensional change. According to the results, the groups that presented the smaller changes were the ones that passed by the sprinkling technique. Regarding the type of material used (glutaraldehyde and sodium hypochlorite), the results showed no statistically significant differences in the stability of alginate impressions
Subject(s)
Disinfection , Disinfectants , Glutaral/chemistry , Sodium Hypochlorite/chemistry , Dental Impression Materials , Solutions , Analysis of VarianceABSTRACT
Purpose: The aim of this study was to determine the effect of disinfectant procedures on the dimensional stability and surface quality of a tissue conditioner used as a functional impression material. Materials and Methods: A tissue conditioner (Visco-gel) used as a functional impression material was disinfected by immersion in 5.25% sodium hypochlorite or 2% glutaraldehyde solutions for 10 or 20 minutes, respectively. The control group consisted of specimens (n=10) that were not treated by disinfectants. For testing the dimensional stability, impressions of an aluminum edentulous arch with three reference points were made. After 24 hours of storage in distilled water, the specimens were treated by one of the disinfection procedures. Impressions were poured and, subsequently, 50 stone casts were measured with a Nikon profile projector. For surface roughness evaluation, disks that contained Visco-gel were pressed against glass slides. The disks were then stored in distilled water for 24 hours. After disinfection, 50 disk-shaped dental stone casts were prepared. Surface roughness values were determined using a profilometer. For each test, data were subjected to two-way analysis of variance (ANOVA) followed by Tukey's test (α = 0.05). Results: The results of the dimensional stability test showed that immersion of Visco-gel impressions in 5.25% sodium hypochlorite solution or 2% glutaraldehyde solution did not significantly change the anteroposterior (AP) and cross-arch (CA) distances of the resultant stone casts when compared to the control group (P>0.05). The surface quality of dental stone casts formed by Visco-gel did not change significantly when impressions were immersed in the disinfectant solutions for either 10 or 20 minutes, or when stored in distilled water (P>0.05). Conclusion: The results showed that the disinfectant solutions used in this study did not have a significant effect on the surface quality and dimensional accuracy of Visco-gel as a functional impression material.
Subject(s)
Biocompatible Materials/chemistry , Dental Arch/pathology , Dental Disinfectants/chemistry , Dental Impression Materials/chemistry , Dental Impression Technique , Models, Dental , Disinfection/methods , Elasticity , Glutaral/chemistry , Humans , Jaw, Edentulous/pathology , Methylmethacrylates/chemistry , Models, Anatomic , Sodium Hypochlorite/chemistry , Surface Properties , Temperature , Time Factors , Tissue Conditioning, Dental , Water/chemistryABSTRACT
Glutaraldehyde is the fixative most commonly used in electron microscope studies of biological tissues, however it is often necessary to use samples which were not fixed in this fixative, even with the usual uncertainty of the results that may be obtained. The fixation is the more delicate step of the sample processing. Therefore in this work, the quality of preservation of haemal nodes fixed with two classic aldehyde fixatives: formaldehyde and glutaraldehyde we have compared under the scanning electron microscope. Our results showed that both fixatives were successful in preserving the morphology of haemal nodes components; however glutaraldehyde conferred satisfactory results mainly in the preservation of parenchymal cells, whereas formaldehyde was better for preservation of stromal fibres.
El glutaraldehido es el fijador que se utiliza con más frecuencia en estudios en los tejidos biológicos a través microscopía electrónica. Sin embargo, a menudo es necesario utilizar muestras que no han sido fijadas con este fijador, aún con la incertidumbre de los resultados que se puedan obtener. La fijación es el paso más importante en el procesamiento de los tejidos. Por lo anterior, hemos efectuado este estudio comparando la calidad de conservación de nodos linfáticos hemales fijados con formaldehido y glutaraldehido. Los resultados muestran que ambos fijadores conservaron adecuadamente la morfología de los componentes de los nodos linfáticos hemales, sin embargo, el glutaraldehido conservó en mejores condiciones, principalmente, las células del parénquima, pero el formaldehido conservó mejor las fibras del estroma en nodos linfáticos.
Subject(s)
Animals , Tissue Fixation/methods , Glutaral/chemistry , Formaldehyde/chemistry , Lymph Nodes/ultrastructure , Organ Preservation/methods , Sheep , Microscopy, Electron, Scanning , Aldehydes/chemistryABSTRACT
OBJECTIVES: To assess and to compare the effects of Gluma® Desensitizer (GDL) with an experimental glutaraldehyde and HEMA containing fumed silica dispersion (GDG) on dentin permeability using a chemiluminous tracer penetration test. MATERIAL AND METHODS: Twenty disc-shaped dentin specimens were dissected from extracted human third molars. The dentin specimens were mounted in a split chamber device for determination of permeability under liquid pressure using a photochemical method. Ten specimens were randomly selected and allocated to the evaluation groups Gluma® Desensitizer as aqueous solution and glutaraldehyde/HEMA as fumed silica dispersion, respectively. Dentin disc permeability was determined at two pressure levels after removal of smear with EDTA, after albumin soaking, and after application of the desensitizing agents. Two desensitizer-treated and rinsed specimens of each group were examined by scanning electron microscopy (SEM) for surface remnants. RESULTS: Comparatively large standard deviations of the mean EDTA reference and albumin soaked samples permeability values refected the differences of the dentin substrates. The mean chemiluminescence values of specimen treated with GDL and GDG, respectively, were signifcantly reduced after topical application of the desensitizing agents on albumin-soaked dentin. The effects of GDL and GDG on permeability were not signifcantly different. Treated specimens showed no surface remnants after rinsing. CONCLUSIONS: The experimental desensitizer gel formulation reduced dentin permeability as effectively as the original Gluma® Desensitizer solution.
Subject(s)
Humans , Dentin Desensitizing Agents/pharmacology , Dentin Permeability/drug effects , Dentin/drug effects , Glutaral/pharmacology , In Vitro Techniques , Methacrylates/pharmacology , Dentin Desensitizing Agents/chemistry , Dentin Sensitivity/drug therapy , Glutaral/chemistry , Luminescence , Materials Testing , Microscopy, Electron, Scanning , Methacrylates/chemistry , Random Allocation , Silicon Dioxide/chemistry , Surface Properties/drug effectsABSTRACT
This study evaluated the release of glutaraldehyde from heat-polymerized acrylic resins subjected to disinfection followed by chemical and mechanical polishing. Ninety disc-shaped specimens (15 x 4 mm), 30 per resin (Lucitone 550, QC-20 and Classico), were made and assigned to 2 groups according to the type of polishing. One side of each specimen was not polished and the other was either mechanically (n=45) or chemically (n=45) polished, and immersed in water at 50°C for 1 h to allow the release of intrinsic substances and then kept in distilled water for 7 days. The specimens were disinfected by immersion in 2% glutaraldehyde for 10 min. After this period, 3 specimens from each group were immersed in water for 15, 30, 60, 120 and 240 min. For the 15-, 30-, 60-min immersions, 4 water exchanges were done at the end of period. High performance liquid chromatography (HPLC) was used to detect and quantify the glutaraldehyde released after each period. Data were analyzed statistically by two-way ANOVA and multiple comparisons were done by Tukeys and Scheffés tests (α=0.05). No glutaraldehyde release was observed from the specimens with chemical polishing at any of the immersion periods, while the mechanically polished specimens released glutaraldehyde. In the groups with water exchanges, Lucitone released more disinfectant in the 15-min period (0.040 μg/mL), Classico in the 30-min (0.021 μg/mL) and 60-min (0.018 μg/mL) periods, and QC-20 the same amount (-1.760 μg/mL) in all periods. In the groups without water exchanges, Lucitone released the highest amount of disinfectant (-1.370 μg/mL), differing significantly from QC-20 (0022 g/mL) and Classico (0019 g/mL), which were similar. The findings of this showed that chemically polished specimens from the 3 resin brands did not release glutaraldehyde after different periods of immersion, while glutaraldehyde release was observed from the mechanically polished specimens, especially from those made of Lucitone resin.
Este estudo determinou a liberação de glutaraldeído de resinas acrílicas termopolimerizáveis submetidas a polimento químico e mecânico e desinfetadas. Noventa corpos-de-prova circulares (15 x 4 mm), 30 de cada tipo de resina (Lucitone, QC-20 e Clássico), foram confeccionados e divididos em 2 grupos referentes ao tipo de polimento. Um dos lados de cada corpo-de-prova não foi polido e o outro foi polido mecanicamente (n=45) ou quimicamente (n=45), e imersos em água aquecida a 50°C por 1 h para liberação de substâncias intrínsecas e mantidos em água destilada por 7 dias. A seguir era realizada a desinfecção por imersão em solução de glutaraldeído a 2% por 10 min. Decorrido este período, três corpos-de-prova de cada grupo eram imersos em água por 15, 30, 60, 120 e 240 min. Nos períodos de 15, 30 e 60 min foram realizadas até 4 trocas de água após cada período. As amostras eram analisadas por meio de cromatografia líquida de alta eficiência (HPLC) após cada período. Os dados foram analisados estatisticamente pela Análise de Variância e testes complementares de Tukey e Scheffé (α=0,05). Os corpos-de-prova com polimento químico, de todas as marcas comerciais de resina, não liberaram glutaraldeído em qualquer um dos períodos de imersão em água, enquanto os com polimento mecânico liberaram. Nos grupos com trocas de água, a resina Lucitone liberou maior quantidade de desinfetante nas trocas de 15 min (0,040 μg/mL), a resina Clássico nas de 30 (0,021 μg/mL) e 60 min (0,018 μg/mL) e a QC-20 liberou a mesma quantidade (-1,760 μg/mL), em todos os períodos de imersão em água. Nos grupos sem trocas de água, a resina Lucitone liberou maior quantidade de desinfetante (-1,370 μg/mL), sendo diferente estatisticamente das resinas QC-20 (0,022 μg/mL) e Clássico (0,019 μg/mL), que são similares. Pelos resultados conclui-se que corpos-de-prova polidos quimicamente, das três marcas comerciais de resina, não liberaram glutaraldeído após os diferentes períodos de imersão. Contudo, nos corpos-de-prova polidos mecanicamente houve liberação do desinfetante, com Lucitone liberando maior quantidade em relação às demais resinas estudadas.
Subject(s)
Humans , Acrylic Resins/chemistry , Dental Disinfectants/chemistry , Dental Materials/chemistry , Dental Polishing/methods , Disinfection/methods , Glutaral/chemistry , Chromatography, High Pressure Liquid , Dental Polishing/instrumentation , Hot Temperature , Immersion , Materials Testing , Methylmethacrylate/chemistry , Polymerization , Polymethyl Methacrylate/chemistry , Temperature , Time Factors , Water/chemistryABSTRACT
Background and Objectives: This in-vitro study was conducted to evaluate the strength and properties of Type III and Type IV gypsum mixed with disinfectant solutions. Materials and Methods: Type III and Type IV gypsum were used for the study. Three different mixing solutions namely waterqueous solutions of 0.525% sodium hypochlorite and 2% glutaraldehyde were used. Gypsum materials were subjected to further modification by adding a mixture of 1.0% gum arabic and 0.132% calcium hydroxide before mixing with the disinfectant solutions, at two different liquid/powder (L/P) ratios for each. Both, the unmodified and the modified gypsum were tested for compressive and tensile strength after one hour and one week from the start of the mix. The crystalline configuration of the fracture fragments of the unmodified and modified set gypsum were studied under the scanning electron microscope. Results: The disinfectant solutions reduced the strength of both Type III and Type IV gypsum. Water showed higher-strength, which was followed by 0.525% sodium hypochlorite and 2% glutaraldehyde. The modified Type III and Type IV gypsum with reduced L/P ratio also showed strength values less than that of the control groups. Interpretation and Conclusion: Chemical disinfectants reduced the strength of gypsum when used as water substitutes. Gum Arabic and calcium hydroxide additives permitted lower L/P ratio, however, there was still excess water retained in the set gypsum that lowered the strength values of Type III and Type IV gypsum. Hence, further reduction of L/P ratio may increase the properties of the modified Type III and Type IV gypsum.
Subject(s)
Calcium Hydroxide/chemistry , Calcium Sulfate/chemistry , Compressive Strength , Crystallography , Dental Disinfectants/chemistry , Dental Materials/chemistry , Dental Stress Analysis/instrumentation , Glutaral/chemistry , Gum Arabic/chemistry , Humans , Humidity , Materials Testing , Mechanical Phenomena , Microscopy, Electron, Scanning , Powders , Sodium Hypochlorite/chemistry , Solutions , Stress, Mechanical , Tensile Strength , Time Factors , Water/chemistryABSTRACT
El objetivo de este estudio fue evaluar la eficacia de agentes de desinfección indicados para polisulfuros (mercaptanos), poliéteres y siliconas por condensación y por adición. Fueron confeccionadas noventa muestras de cada material, siendo treinta de ellas contaminadas con Streptococcus mutans o Staphylococcus aureus o Candida albicans. De cada solución microbiana fueron retiradas diez muestras del polisulfeto y de ambas las siliconas, que fueron inmersas por diez minutos en glutaraldehído al 2 por ciento y otras diez inmersas en agua destilada estéril (control negativo). Después de un nuevo lavado en agua destilada, las muestras fueron transferidas a medios de cultivo estériles. Las diez muestras restantes no fueron sometidas al agente de desinfección y fueron transferidas a medios asociados a agentes antimicrobianos específicos (control positivo). La turbidez de los medios de cultivo fue evaluada como indicativo del crecimiento microbiano siguiéndose a la incubación por 24 h a 37O C y se realizó la dilución y sembrado en placas de Petri para contar las colonias. Para el poliéter fue ejecutado el mismo procedimiento, pero el agente de desinfección usado fue el hipoclorito de sodio a 1. No hubo turbidez comprobatoria del crecimiento microbiano en ninguno de los medios de cultivo que contenían los especimenes sometidos a los agentes de desinfección. Se concluyó que el glutaraldehído al 2 por ciento es un agente de desinfección eficaz para el polisulfuro y para las siliconas por adición y por condensación, así como el hipoclorito a 1 por ciento es eficaz para el poliéter, para los microorganismos evaluados
The aim of this in vitro study was to evaluate the disinfection efficacy of elastomeric impression materials such as polysulfides, polyethers, condensation and addition silicones. Ninety samples of each material were made and every thirty samples contaminated with Streptococcus mutans or Staphylococcus aureus or Candida albicans. From each microbial solution there were taken ten samples of polysulfide and of both silicones which were immersed for ten minutes in a 2% glutaraldehyde solution and other ten immersed in sterile distilled water (negative control). After being washed again in distilled water, the samples were transferred to sterile culture medium. The last ten samples were not submitted to any disinfection agent and were transferred to mediums associated with specific anti-microbial agents (positive control). The turbidity of the culture mediums was evaluated as an indication of the microbial growth after a period of 24-hour incubation at 37oC and the dilution and seeding in Petri dishes were done to count the colonies. The same procedure was done for the polyether, but the disinfection agent used was 1% sodium hypoclorite. There was no proved turbidity of the microbial growth in any of the culture mediums which had samples submitted to the disinfection agents tested. It was concluded that the 2% glutaraldehyde is an effective disinfection agent to polysulfides and to both condensation and addition silicones, as well as 1% sodium hypoclorite is effective to polyether, for the tested microorganisms.
O objetivo deste estudo in vitro foi avaliar a eficácia de agentes de desinfecção indicados para polissulfetos, poliéteres e siliconas de condensação e adição. Foram confeccionadas noventa amostras de cada material, sendo cada trinta contaminadas com Streptococcus mutans, Staphylococcus aureus ou Candida albicans. De cada solução microbiana foram retiradas dez amostras do polissulfeto e de ambas as siliconas, que foram imersas por dez minutos no glutaraldeído a 2% e outras dez imersas em água destilada estéril (controle negativo). Após nova lavagem em água destilada, as amostras foram transferidas para meios de cultura estéreis. As dez amostras restantes não foram submetidas ao agente de desinfecção e foram transferidas para meios associados a agentes antimicrobianos específicos (controle positivo). A turbidez dos meios de cultura foi avaliada como indicativo de crescimento microbiano após incubação por 24 h a 37O C e realizou-se a diluição e semeadura nas placas de Petri para contagem de colônias. Para o poliéter foi executado o mesmo procedimento, porém o agente de desinfecção empregado foi o hipoclorito de sódio a 1%. Não houve turvação comprobatória de crescimento bacteriano em nenhum dos meios da cultura que continham corpos de prova submetidos aos agentes de desinfecção. Concluiu-se que o glutaraldeído a 2% é um agente de desinfecção eficaz para o polissulfeto e para as siliconas por adição e por condensação, assim como o hipoclorito a 1% é eficaz para o poliéter, para os microorganismos testados.
Subject(s)
Infection Control, Dental/instrumentation , Disinfectants/classification , Glutaral/chemistry , Sodium Hypochlorite/chemistry , Dental Impression Materials/standards , Silicone Elastomers , American Dental Association , Clinical Protocols , Colony Count, Microbial , Culture Media , Candida albicans/isolation & purification , Polyesters , Sulfides , Staphylococcus aureus/isolation & purification , Streptococcus mutans/isolation & purificationABSTRACT
To increase the biocompatibility and durability of glutaraldehyde (GA)-fixed valves, a biological coating with viable endothelial cells (ECs) has been proposed. However, stable EC layers have not been formed successfully on GA-fixed valves due to their inability to repopulate. In this study, to improve cellular adhesion and proliferation, the GA-fixed prostheses were detoxified by treatment with citric acid to remove free aldehyde groups. Canine bone marrow mononuclear cells (MNCs) were differentiated into EC-like cells and myofibroblast-like cells in vitro. Detoxified prostheses were seeded and recellularized with differentiated bone marrow-derived cells (BMCs) for seven days. Untreated GA-fixed prostheses were used as controls. Cell attachment, proliferation, metabolic activity, and viability were investigated and cell-seeded leaflets were histologically analyzed. On detoxified GA-fixed prostheses, BMC seeding resulted in uninhibited cell proliferation after seven days. In contrast, on untreated GA-fixed prostheses, cell attachment was poor and no viable cells were observed. Positive staining for smooth muscle a-actin, CD31, and proliferating cell nuclear antigen was observed on the luminal side of the detoxified valve leaflets, indicating differentiation and proliferation of the seeded BMCs. These results demonstrate that the treatment of GA-fixed valves with citric acid established a surface more suitable for cellular attachment and proliferation. Engineering heart valves by seeding detoxified GA-fixed biological valve prostheses with BMCs may increase biocompatibility and durability of the prostheses. This method could be utilized as a new approach for the restoration of heart valve structure and function in the treatment of end-stage heart valve disease.
Subject(s)
Dogs , Animals , Tissue Fixation , Tissue Engineering/methods , Swine , Proliferating Cell Nuclear Antigen/analysis , Muscle, Smooth/chemistry , Microscopy, Electron, Scanning , Immunohistochemistry , Heart Valves/cytology , Heart Valve Prosthesis , Glutaral/chemistry , Endothelial Cells/cytology , Cell Survival/physiology , Cell Proliferation , Cell Differentiation/physiology , Cell Culture Techniques/methods , Cell Adhesion/physiology , Bone Marrow Cells/chemistry , Platelet Endothelial Cell Adhesion Molecule-1/analysis , Actins/analysisABSTRACT
La utilidad de los procedimientos de asepsia y antisepsia, desinfección y esterilización, no tienen discusión, más aún en la práctica odontológica, donde está demostrada la posibilidad de contaminación cruzada con organismos altamente patógenos. En esta revisión se describen algunos conceptos nuevos relacionados con métodos de esterilización y mecanismos de acción de las sustancias utilizadas con este fin y se recuerdan los procedimientos a seguir para la obtención de una adecuada bioseguridad
Subject(s)
Antisepsis , Asepsis , Infection Control, Dental/methods , Sterilization/methods , Biguanides/chemistry , Dental Offices/standards , Disinfection/methods , Formaldehyde/chemistry , Glutaral/chemistry , Hot Temperature , Iodine Compounds/chemistry , Phenol/chemistry , Quaternary Ammonium Compounds/chemistry , SteamABSTRACT
O objetivo deste trabalho foi avaliar o potencial carcinogênico do formocresol e do glutaraldeído, nas concentraçöes utilizadas clinicamente, em testes de longa duraçäo, a partir do modelo experimental em hamsters sírius dourados para estudo da carcinogênese química bucal induzida pelo uso do DMBA a 0,5 por cento. A análise comparativa macro e microscópica das alteraçöes provocadas pela aplicaçäo tópica do formocresol diluído a 1/5 e glutaraldeído a 2 por cento sobre a mucosa lingual lateral, precedida ou näo por escarificaçäo, após 7, 13 e 20 semanas, permitiu verificar que o formocresol diluído a 1/5 e o glutaraldeído a 2 por cento induzem alteraçöes morfológicas que caracterizam displasia epitelial; näo houve induçäo à formaçäo de papilomas e carcinomas nos animais, tal como ocorreu com o DMBA a 0,5 por cento
Subject(s)
Animals , Cricetinae , Male , Female , 9,10-Dimethyl-1,2-benzanthracene/analysis , 9,10-Dimethyl-1,2-benzanthracene/chemistry , Formocresols/analysis , Formocresols/chemistry , Glutaral/analysis , Glutaral/chemistry , Carcinogens/analysis , Carcinogens/chemistryABSTRACT
A necessidade de se avaliar o potencial cariogênico do formocresol e glutaraldeído, nas concentraçöes utilizadas clinicamente, em testes de longa duraçäo, motivou a realizaçäo deste trabalho, a partir do modelo experimental em hamsters sírios dourados para o estudo da cariogênese química bucal induzida pelo uso do DMBA a 0,5 por cento. A análise comparativa das evoluçöes macroscópica e microscópicas das alteraçöes provocadas pela aplicaçäo tópica do formocresol diluido a 1/5 e do glutaraldeído a 2 por cento sobre a mucosa lingual lateral, precedida ou näo pelo procedimento de trauma por escarificaçäo, após 7, 13 e 20 semanas, permitiu verificar que: 1) O formocresol diluído a 1/5 e o glutaldeído a 2 por cento induzem alteraçöes epiteliais hiperplásicas nos locais das aplicaçöes, mas sem modificaçöes morfológicas que caracterizam displasia epitelial; 2) Näo houve induçäo à formaçäo de papilomas e carcinomas nos animais em que foram aplicados formocresol diluído 1/5 e glutaraldeído a 2 por cento, na mucosa da borda lateral da língua de hamster, tal como foi feito com o DMBA a 0,5 por cento. Desta forma, podê-se concluir que, o formocresol diluído a 1/5 e o glutaraldeído a 2 por cento, quando comparados ao DMBA a 0,5 por cento no mesmo método de aplicaçäo, näo säo carcinógenos completos