Increased whitening efficacy and reduced cytotoxicity are achieved by the chemical activation of a highly concentrated hydrogen peroxide bleaching gel

Abstract Objective This study was designed for the chemical activation of a 35% hydrogen peroxide (H2O2) bleaching gel to increase its whitening effectiveness and reduce its toxicity. Methodology First, the bleaching gel - associated or not with ferrous sulfate (FS), manganese chloride (MC), peroxidase (PR), or catalase (CT) - was applied (3x 15 min) to enamel/dentin discs adapted to artificial pulp chambers. Then, odontoblast-like MDPC-23 cells were exposed for 1 h to the extracts (culture medium + components released from the product), for the assessment of viability (MTT assay) and oxidative stress (H2DCFDA). Residual H2O2 and bleaching effectiveness (DE) were also evaluated. Data were analyzed with one-way ANOVA complemented with Tukey's test (n=8. p<0.05). Results All chemically activated groups minimized MDPC-23 oxidative stress generation; however, significantly higher cell viability was detected for MC, PR, and CT than for plain 35% H2O2 gel. Nevertheless, FS, MC, PR, and CT reduced the amount of residual H2O2 and increased bleaching effectiveness. Conclusion Chemical activation of 35% H2O2 gel with MC, PR, and CT minimized residual H2O2 and pulp cell toxicity; but PR duplicated the whitening potential of the bleaching gel after a single 45-minute session.

Chitosan-collagen biomembrane embedded with calcium-aluminate enhances dentinogenic potential of pulp cells

Abstract The development of biomaterials capable of driving dental pulp stem cell differentiation into odontoblast-like cells able to secrete reparative dentin is the goal of current conservative dentistry. In the present investigation, a biomembrane (BM) composed of a chitosan/collagen matrix embedded with calcium-aluminate microparticles was tested. The BM was produced by mixing collagen gel with a chitosan solution (2:1), and then adding bioactive calcium-aluminate cement as the mineral phase. An inert material (polystyrene) was used as the negative control. Human dental pulp cells were seeded onto the surface of certain materials, and the cytocompatibility was evaluated by cell proliferation and cell morphology, assessed after 1, 7, 14 and 28 days in culture. The odontoblastic differentiation was evaluated by measuring alkaline phosphatase (ALP) activity, total protein production, gene expression of DMP-1/DSPP and mineralized nodule deposition. The pulp cells were able to attach onto the BM surface and spread, displaying a faster proliferative rate at initial periods than that of the control cells. The BM also acted on the cells to induce more intense ALP activity, protein production at 14 days, and higher gene expression of DSPP and DMP-1 at 28 days, leading to the deposition of about five times more mineralized matrix than the cells in the control group. Therefore, the experimental biomembrane induced the differentiation of pulp cells into odontoblast-like cells featuring a highly secretory phenotype. This innovative bioactive material can drive other protocols for dental pulp exposure treatment by inducing the regeneration of dentin tissue mediated by resident cells.

Detection of Organochlorine Compounds Formed During the Contact of Sodium Hypochlorite with Dentin and Dental Pulp

This study used gas chromatography-mass spectrometry (GC-MS) to detect the products formed during the contact of sodium hypochlorite (NaOCl) with bovine pulp and dentin. For analysis of the products formed in the volatile phase, 11 mg of bovine pulp tissue were placed in contact with 0.5%, 2.5% and 5.25% NaOCl until complete tissue dissolution occurred. The solid phase microextraction (SPME) fiber was exposed inside the container through the cover membrane and immediately injected into the GC-MS system. 30 mg of the of dentin were kept in contact with NaOCl, and then the SPME fiber was exposed inside the container through the cover membrane for adsorption of the products and injected into the GC-MS system. The same protocol was used for the aqueous phase. For analysis of the volatile compounds, the final solution was extracted using pure ethyl ether. The suspended particulate phase of the mixture was aspirated, and ether was separated from the aqueous phase of the solution. The ether containing the products that resulted from the chemical interaction of dentin and pulp with the NaOCl was filtered and then injected into the GC-MS system for analysis of the aqueous phase. The aqueous and volatile phases of both dentin and pulp showed the formation of chloroform, hexachloroethane, dichloromethylbenzene and benzaldehyde. In conclusion, organochlorine compounds are generated during the contact of dentin and pulp with NaOCl at concentrations of 0.5%, 2.5% and 5.25%.

Este estudo utilizou a cromatografia gasosa acoplada a espectrometria de massa (CG-MS) para detectar os produtos que se formaram durante o contato de hipoclorito de sódio (NaOCl) com polpa dental bovina e dentina. Para a análise dos produtos formados na fase volátil, 11 mg de polpa bovina foram colocados em contato com 0,5 % , 2,5 % e 5,25 % de NaOCl, até à dissolução completa dos tecidos. A fibra de microextração em fase sólida (SPME) era exposta dentro do recipiente através da membrana da tampa, por 15 minutos, para a adsorção dos produtos formados e imediatamente injetada no CG-MS para análise. Para a análise da dentina, 30 mg do de amostras foram mantidas em contacto com o NaOCl, por 15 min, e então a fibra de SPME era exposta no interior do recipiente através da membrana de cobertura para a adsorção dos produtos e injectado no sistema de GC-MS. O mesmo protocolo foi utilizado para a fase aquosa. Para a análise dos compostos voláteis, a solução final foi extraída com éter etílico puro. A fase de partículas em suspensão da mistura foi aspirada, e o éter foi separado da fase aquosa da solução. O éter contendo os produtos que resultaram da interacção química da dentina e polpa com hipoclorito de sódio foi filtrado e, em seguida, injectado no sistema GC-MS para análise da fase aquosa. As fases aquosas e voláteis de dentina e polpa mostraram a formação de clorofórmio, hexacloroetano, dichloromethylbenzene e benzaldeído. Compostos organoclorados são gerados durante o contacto da dentina e polpa com hipoclorito de sódio em concentrações de 0,5 % , 2,5 % e 5,25 %.

Pulp Tissue Dissolution Capacity of Sodium Hypochlorite Combined with Cetrimide and Polypropylene Glycol

This study evaluated the influence of the addition of cetrimide and polypropylene glycol to sodium hypochlorite (NaOCl) on its capacity to dissolve pulp tissue. Bovine pulp fragments with standardized weight and volume were immersed for 5, 15 and 30 min in 2 mL of NaOCl and Hypoclean (NaOCl added with cetrimide and polypropylene glycol) solutions at 5.25%, 2.5%, 1%, 0.5% and 0.25% and afterwards re-weighted. Distilled water was used as a control. The percentage of tissue loss was considered for statistical analysis (univariate ANOVA, SPSS, v. 17.0) at 5% significance level. There was no tissue dissolution in the control group. NaOCl added with surfactants (Hypoclean) dissolved more pulp tissue (p<0.05) than NaOCl alone. Tissue dissolution was directly dependent on the concentration of solutions (p<0.05), and also on the time range (p<0.05). The combination of NaOCl at high and low concentrations with the surfactants cetrimide and polypropylene glycol increased significantly its capacity to dissolve pulp tissue.

Este estudo avaliou a influência da adição de cetramida e polipropilenoglicol ao hipoclorito de sódio (Hypoclean) na capacidade de dissolução pulpar do hipoclorito de sódio (NaOCl). Fragmentos de tecido pulpar bovino, com peso e volume padronizados foram imersos por períodos de 5, 15 e 30 min em 2 mL de NaOCl ou Hypoclean nas concentrações 5,25%, 2,5%, 1%, 0,5% e 0,25%. Após a imersão nas soluções testadas, os fragmentos foram novamente pesados. Como controle, foi utilizada água destilada. O percentual de perda tecidual foi considerado para análise estatística (ANOVA univariada, SPSS, v. 17.0). Não houve dissolução tecidual no grupo controle. A solução de NaOCl combinada a surfactantes (Hypoclean) dissolveu um maior percentual de tecido pulpar (p<0,05) que o NaOCl sem associações. A dissolução tecidual foi diretamente dependente da concentração das soluções (p<0,05), assim como do tempo de exposição às soluções (p<0,05). A adição dos surfactantes cetramida e polipropilenoglicol ao NaOCl em concentrações altas e baixas aumentou significativamente sua capacidade de dissolução do tecido pulpar.

Tenascin and Fibronectin Expression after Pulp Capping with Different Hemostatic Agents: A Preliminary Study

This study investigated the expression of extracellular matrix glycoproteins tenascin (TN) and fibronectin (FN) in pulp repair after capping with calcium hydroxide (CH), following different hemostasis protocols. Class I cavities with a pulp exposure were prepared in 42 human third molars scheduled for extraction. Different hemostatic agents (0.9% saline solution, 5.25% sodium hypochlorite and 2% chlorhexidine digluconate) were used and pulps were capped with CH cement. After 7, 30 or 90 days, teeth were extracted, formalin-fixed, and prepared for immunohistochemical technique. Hemostatic agents did not influence the expression of TN and FN. Both glycoproteins were found in the entire the pulp tissue and around collagen fibers, but were absent in the mineralized tissues. In the predentin, TN showed positive immunostaining and FN had a variable expression. Within 7 days post-treatment, a slightly more pronounced immunostaining on the pulp exposure site was observed. Within 30 days, TN and FN demonstrated a positive expression around the dentin barrier and at 90 days, a thin and linear expression of TN and FN was delimitating the reparative dentin. In conclusion, hemostatic agents did not influence TN and FN expression. Immunostaining for TN and FN was seen in different regions and periods, demonstrating their role in pulp repair.

Este estudo investigou a expressão das glicoproteínas Tenascina (TN) e Fibronectina (FN) da matriz extracelular no reparo pulpar após capeamento com hidróxido de cálcio (HC), seguindo diferentes protocolos de hemostasia. Cavidades de classe I com exposição pulpar foram preparadas em 42 terceiros molares humanos indicados para extração. Diferentes agentes hemostáticos (solução salina a 0,9%, hipoclorito de sódio a 5,25% e clorexidina a 2%) foram usados e as polpas foram capeadas com cimento de HC. Após 7, 30 ou 90 dias, os dentes foram extraídos, fixados em formalina e preparados para análise imunoistoquímica. Os agentes hemostáticos não influenciaram a expressão de TN e FN. Ambas glicoproteínas foram encontradas em todo tecido pulpar, ao redor das fibras colágenas e estiveram ausentes nos tecidos mineralizados. Na pré-dentina, a TN mostrou forte imunoexpressão e a FN teve uma expressão variável. Após 7 dias, foi observada uma expressão levemente mais pronunciada no lugar da exposição pulpar. Aos 30 dias, a TN e a FN demonstraram uma expressão mais forte sob a barreira dentinária e aos 90 dias, uma expressão fina e linear da TN e FN apresentava-se delimitando a dentina reparativa. Em conclusão, os agentes hemostáticos não influenciaram e expressão da TN e da FN. A imunoexpressão da TN e FN foi observada em diferentes regiões e períodos, demonstrando o seu papel no reparo pulpar.

Contenido químico de soluciones después de la irrigación del conducto radicular dentario / Chemical content of solutions after irrigation of the tooth root canal / Conteúdo químico das soluções após a irrigação do canal dentário radicular

Durante el tratamiento endodóntico, la irrigación del conducto radicular permite remover los residuos de los túbulos dentinarios. El objetivo de este estudio fue evaluar el contenido de soluciones de irrigación extraídas del conducto radicular luego de la pulpectomía en dientes con pulpitis y con necrosis pulpar, con el fin de determinar aquéllas menos agresivas sobre la dentina radicular. Se trabajó en 80 dientes humanos superiores unirradiculares y con NaClO 1%, EDTA 17%, Ca(OH)2 1%, clorhexidina 0,2% y agua destilada. Se aspiró el contenido de tres irrigaciones y se determinó pH, proteínas totales, hidroxiprolina, calcio y fósforo. El pH de las soluciones no tuvo cambios significativos. La mayor concentración de proteínas se halló en los aspirados con NaClO de dientes con necrosis y con EDTA de pulpitis, revelando mayor número de bandas por electroforesis con esta última solución. El contenido de hidroxiprolina fue mayor con Ca(OH)2 y con clorhexidina, y el de fósforo con EDTA y con NaClO para ambos tipos de dientes. Se detectó calcio con NaClO y clorhexidina. No hubo resultados diferentes entre dientes con pulpitis y con necrosis pulpar en todas las determinaciones químicas. Las soluciones de NaClO y EDTA resultaron eficaces en la eliminación de restos orgánicos de los conductos radiculares. Sin embargo, NaClO eliminó también calcio y fósforo; y la solución de EDTA, fósforo, posiblemente provenientes de la hidroxiapatita y de complejos proteicos de la dentina.

During endodontic treatment, irrigation of the root canal makes it possible to remove remainders of the dentin tubules. The aim of this study was to evaluate the content of extracted irrigation solutions of root canals after pulpectomy in teeth with pulpitis and pulp necrosis, in order to determine those Enless aggressive on root dentine. Work was performed on 80 unirradicular upper human teeth, with 1% NaClO, 17% EDTA, 1% Ca(OH)2, 0.2% chlorhexidine and distilled water. The content of three irrigations was aspired and pH, total proteins, hydroxiproline, calcium and phosphor were determined. pH of the solutions showed no significant changes. A greater protein concentration was obtained with NaClO from teeth with necrosis and with EDTA from teeth with pulpitis; the greatest number of electrophoretic bands were revealed with EDTA. The hydroxiproline content was greater with Ca(OH)2 and with chlorhexidine, and that of phosphor was greater with EDTA and with NaClO for both types of teeth. Calcium was detected with NaClO and chlorhexidine. There were no different results between teeth with pulpitis and those with pulp necrosis in all chemical determinations. NaClO and EDTA solutions were effective in the elimination of organic rests from the root canal. Nevertheless, NaClO also eliminated calcium and phosphor, and the EDTA solution eliminated phosphor, possibly originated from hydroxiapatite and from protein complexes of dentin.

Durante o tratamento do endodóntico, a irrigação do canal radicular permite remover os resíduoss dos túbulos dentinários. O objetivo deste estudo foi avaliar o conteúdo das soluções de irrigação extraídas do canal radicular após a pulpectomia em dentes com pulpite e com necrose pulpar, com a finalidade de determinar aquelas menos agresivas sobre a dentina radicular. O trabalho foi em 80 dentes humanos superiores unirradiculares e com NaClO 1%, EDTA 17%, Ca(OH)2 1%, clorexidina 0.2% e água destilada. Foi aspirado o conteúdo de três irrigações e se determinou pH, proteínas totais, hidroxiprolina, cálcio e fósforo. O pH das soluções não teve mudanças significativas. A maior concentração de proteínas foi encontrada nas aspirações com NaClO de dentes com necrose e o EDTA da pulpite, revelando maior número de faixas por eletroforese com esta última solução. O conteúdo de hidroxiprolina foi maior com Ca(OH)2 e com clorexidina, e o de fósforo com EDTA e com NaClO para ambos os tipos de dentes. Foi detectado cálcio com NaClO e clorexidina. Não houve resultados diferentes entre dentes com pulpite e com necrose pulpar em todas as determinações químicas. As soluções de NaClO e EDTA resultaram eficazes na eliminação de restos orgânicos dos condutos radiculares. Entretanto, NaClO eliminou também cálcio e fósforo; e a solução de EDTA, fósforo, possivelmente provenientes da hidroxiapatita e de complexos proteicos da dentina.

A biochemical and histopathological evaluation of generalized pulp calcification in young permanent teeth.

Pulp calcifications are a frequent finding on bitewing and periapical radiographs in older age-groups but their occurrence in the entire dentition in young subjects is unusual. We report such an unusual occurrence of generalized pulp calcification in a 13-year-old Indian female. Radiographic examination of the dentition revealed pulp calcifications in all permanent teeth, located mostly in the pulp chamber but with some in the root canals. The patient's dental, medical, and family history was noncontributory. Biochemical analysis of the removed pulp calcification from one of the teeth during endodontic treatment showed large amounts of calcium, phosphorus, and carbonate. However, metabolic evaluation of patient through liver and kidney function tests and other blood investigations did not reveal any metabolic disorder. The patient was also evaluated for any systemic, syndromic, or genetic involvement but this was also noncontributory. Therefore, we propose that this unusual case of generalized pulp calcification is of idiopathic origin. In this work, histopathological and biochemical evaluations of the pulp calcification was done to try and understand the initiation and progress of calcifications in pulpal tissue.

Contenido orgánico de extractos parcialmente purificados de pulpa dental humana y bovina / Organic content of human and bovine dental pulp partially purified extracts / Conteúdo orgânico de extratos parcialmente purificado de polpa dentária humana e bovina

La pulpa dental contiene tejido conectivo rico en proteínas, mayormente colágeno. El objetivo de este trabajo fue describir un método de purificación de componentes orgánicos pulpares humanos y bovinos, vital y necrótico para validar el modelo experimental bovino. Se prepararon extractos con 50 mg de fracción media de pulpas unirradiculares, 20 humanas o 1 bovina, en 500 µL de Tris-HCl 50 mM pH 7,4, floruro de fenil metil sulfonilo 1mM e hidrocloruro de benzamidina 5 mM frío. Se homogeneizó y centrifugó a 10000 rpm. Los sobrenadantes fueron parcialmente purificados con sulfato de protamina 1%, los sedimentos resuspendidos y dializados 2 horas con recambio en acetato de sodio 500 mM pH 6. Se determinaron proteínas, hidroxiprolina e hidratos de carbono, y se calculó el rendimiento según el contenido de hidroxiprolina. Se aplicó electroforesis en geles de poliacrilamida. Se encontró mayor contenido orgánico en tejido humano que en bovino, y en vital que en necrótico. Por hidroxiprolina/proteínas y rendimiento, el extracto bovino contendría mayor proporción de colágeno. En pulpas humanas se obtuvieron bandas a 78 y 80 kDa, y en bovinas a 74 y 76 kDa. No hubo diferencias entre tejido vital y necrótico. Las evidencias cuali y cuantitativas expresadas validarían al modelo bovino en investigaciones endodónticas.

The dental pulp contains connective tissue and is rich in proteins, mainly collagen. The aim of this study was to describe a purification method for organic compounds of human and bovine pulp tissues, either vital as necrotic, in order to validate the experimental bovine model. Extracts of 50 mg of the middle fraction of one root pulp teeth, 20 humans or 1 bovine, in 500 µL of cold 50 mM Tris - HCl pH 7.4, 1 mM phenyl methyl sulfonyl fluoride and 5 mM benzamidine hydrochloride were prepared. Extracts were homogenized and centrifuged at 10000 rpm. Supernatants were partially purified with 1% protamine sulphate, sediments re-suspended and dialyzed during 2 hours with a spare in 500 mM sodium acetate pH 6. Proteins, hydroxiproline and carbohydrates were determined, and the yield of the process was calculated according to the hydroxiproline content. Poliacrylamide gel electrophoresis was applied. A greater organic content was found in human than in bovine tissue, and in vital rather than in the necrotic one. Hydroxyproline/ proteins and yield evidenced that bovine extract would contain a larger proportion of collagen. Bands at 78 and 80 kDa in human pulp and at 74 and 76 kDa in the bovine tissue were observed. There was no difference between vital and necrotic tissues. The qualitative and quantitative evidences expressed in this work would validate the bovine research endodontic model.

A polpa dentária contém tecido conectivo rico em proteínas, na sua maioria colágeno. O objetivo deste trabalho foi descrever um método de puriIcação de componentes orgânicos da polpa dos humanos e bovinos, vitales e necróticos para validar o modelo experimental bovino. Foram preparados extratos com 50 mg de fração média de polpas unirradiculares, 20 humanas ou 1 bovina em 500 µL de Tris-HCl 50 mM pH 7,4, fenil-metil-sulfonil Juoreto 1 mM e hidrocloreto de benzamidina 5 mM frio. Foi homogeneizado e centrifugado a 10.000 rpm. Os sobrenadantes foram parcialmente puriIcados com sulfatos de protamina 1%, os sedimentos ressuspensos e dialisados 2 horas com recâmbio em acetato de sódio 500 mM pH 6. Foram determinadas proteínas, hidroxiprolina e hidratos de carbono e se calculou o rendimento conforme o conteúdo de hidroxiprolina. Foi aplicada eletroforese em géis de poliacrilamida. Maior conteúdo orgânico foi encontrado em tecido humano que em bovino e em vital que em necrótico. Por hidroxiprolina/proteínas e rendimento, o extrato bovino conteria maior proporção de colágeno. Em polpas humanas foram obtidas faixas a 78 e 80 kDa e em bovinas a 74 e 76 kDa. Não houve diferenças entre tecido vital e necrótico. As evidências qualitativas e quantitativas expressas validariam o modelo bovino em pesquisas endodônticas.

Dissolution of bovine pulp tissue in solutions consisting of varying NaOCl concentrations and combined with EDTA

This in vitro study evaluated (1) the dissolution of bovine pulp tissue in solutions consisting of varying NaOCl concentrations and combined with EDTA; and (2) the pH of these solutions before and after the experiment. The independent variables were the concentration and the volume of the solution. Thirty bovine pulps were divided in equal fragments, resulting in 90 fragments of pulp tissue. Each fragment was immersed in one of the following solutions: 1 percent NaOCl (4 ml), 2.5 percent NaOCl (4 ml), 1 percent NaOCl + 17 percent EDTA (2 ml : 2 ml), 1 percent NaOCl + 17 percent EDTA (1 ml : 3 ml), 2.5 percent NaOCl + 17 percent EDTA (2 ml : 2 ml), and 2.5 percent NaOCl + 17 percent EDTA (1 ml : 3 ml). The test solutions were dichotomized as either able or not able to dissolve the tissue, the latter being attributed when the dissolution of the pulp tissue was not complete within 48 hours. When the samples were able to dissolve the tissue, the time required for complete tissue dissolution was submitted to statistical analysis. The pH of the solutions was measured before and after the experiment. The pH variable was dichotomized as either changed or unchanged. The results demonstrated that the NaOCl solutions combined with 17 percent EDTA were not able to dissolve the tissue. The t-test revealed that the 2.5 percent NaOCl solution presented a lower mean dissolution time than the 1 percent NaOCl solution (p < 0.001). The pH of the solutions with equal volumes of NaOCl and EDTA decreased in 48 hours.

Análise do padrão de expressão de MMP-2, -9 e -8 em tecido humano pulpar normal e inflamado / Analysis of the expression perfile of MMP-2, -9 and -8 in normal and inflamed human pulp tissue

As metaloproteinases da matriz (MMPs) foram relacionadas a diversas doenças inflamatórias como artrite e também ao câncer. O presente trabalho tem por objetivo estabelecer o papel da MMP-2, MMP-9 e MMP-8 no processo de inflamação pulpar. Foram adotadas as seguintes hipóteses nulas: (1) o padrão de expressão das MMP-2, MMP-9 e MMP-8 não sofre alteração nos diferentes estágios da polpa humana: normal, reversível, transição, irreversível ou necrose; (2) não há diferença de expressão das MMP-2, -9 e MMP-8, considerando-se um mesmo estágio de inflamação tecidual pulpar. Os métodos utilizados foram: (I) Obtenção dos espécimes, que foram divididos em grupos de acordo com critérios adotados de semiologia subjetiva e objetiva. Obtiveram-se os seguintes grupos: GI (Controle) dentes hígidos (n=7); GII (Pulpite Reversível n=4); GIII (Pulpite Transição n=4); GIV (Pulpite Irreversível/Necrose n=8). Logo após exodontia, os dentes obtidos foram cortados ligeiramente abaixo da junção amelodentinária e fixados em formol a 10% por 48h. Foram lavados em água corrente (24h) para então serem processados histologicamente. Foram obtidas secções de 4m, aderidas em lâminas silanizadas e submetidas à imunomarcação (Técnica da Peroxidase), utilizando os anticorpos anti MMP-2, MMP-9 e MMP-8 humanos. A presença de imunomarcação foi realizada através da análise semi-quantitativa por escores, sendo que a quantificação de marcação por corte seguiu o seguinte escore: 0= ausente; 1= leve; 2= moderada; 3= intensa. Realizou-se teste estatístico não paramétrico Kruskal-Wallis, p<0,05. As comparações intergrupos revelaram, para CO: (1)MMP-2 - GI=GII=GIII, GIII=GIV, GI>GIV (p<0,01) e GII>GIV (p<0,05); (2)MMP-9 GI=GII=GIV, GII=GIII e GIII>GI (p<0,01); (3)MMP-8 GI=GII=GIII=GIV. Na região central da polpa, obteve-se: (1)MMP-2 GI=GII=GIII, GIII=GIV, GI>GIV (p<0,001) e GII>GIV (p<0,01); (2)MMP-9 GI=GII=GIII, GIII=GIV, GIV>GI (p<0,001) e GIV>GII (p<0,01); (3)MMP-8 GI=GII, GIII=GIV, GIII>GI (p<0,05),...

The matrix metalloproteinases (MMPs) have been related to various inflammatory diseases, such as arthritis, as well as to cancer. The aim of the present study was to establish the role of MMP-2, MMP-9 and MMP-8 in the process of dental pulp inflammation. The following null hypotheses were adopted: (1) the pattern of MMP-2, MMP-9 and MMP-8 expression does not undergo alteration in the following different stages of human pulp: normal, reversible, transition, irreversible or necrosis; (2) there is no difference in the expression of MMP-2, -9 and MMP-8, when considering the same stage of pulp tissue inflammation. The methods used were: (I) Obtainment of specimens, which were divided into groups according to the subjective and objective criteria of semiology adopted. The following groups were obtained: GI (Control) healthy teeth (n=7); GII (Reversible Pulpitis n=4); GIII (Transition Pulpitis n=4); GIV (Irreversible Pulpitis/Necrosis n=8). Soon after extraction the teeth obtained were cut slightly below the amelodentinal junction and fixed in 10% formol for 48h. They were washed under running water (24h) and were histologically processed afterwards. Sections of 4m were obtained, adhered to silanized slides, and submitted to immunomarking (Peroxidase Technique), using human anti MMP-2, MMP-9 and MMP- 8 antibodies. The presence of immunomarking was determined through semi-quantitative analysis by scores, and marking by cut was quantified using the following score: 0= absent; 1= slight; 2= moderate; 3= intense. The Kruskal-Wallis non-parametric statistical test was performed, p<0.05. Intergroup comparisons revealed the following: for CO: (1)MMP-2 - GI=GII=GIII, GIII=GIV, GI>GIV (p<0.01) and GII>GIV (p<0.05); (2)MMP-9 GI=GII=GIV, GII=GIII and GIII>GI (p<0,01); (3)MMP-8 GI=GII=GIII=GIV. In the central region of the pulp, the following results were obtained: (1)MMP-2 GI=GII=GIII, GIII=GIV, GI>GIV (p<0.001) and GII>GIV (p<0.01); (2)MMP-9 GI=GII=GIII, GIII=GIV, GIV>GI...

Protein content in irrigating solutions in contact with pulp tissue

Las soluciones de irrigación endodóntica pueden tener distintas accionesLas soluciones de irrigación endodóntica pueden tener distintas acciones. Una de ellas es la de disolver el tejido pulpar. Seevaluó in vitro la capacidad de diferentes soluciones de irrigaciónpara disolver tejido pulpar vital y necrótico mediante un estudio cuanti y cualitativo de proteínas pulpares totales solubles. Se utilizaron pulpas de dientes de bovinos jóvenes, vitales y con necrosis inducida. Se seccionaron en trozos pequeños, que se pesaron y colocaron en 1 ml de las siguientes soluciones: hipoclorito de sodio al 1por ciento y 2,5 por ciento, hidróxido de calcio al 1 por ciento y 5 por ciento, gluconato de clorhexidina al 0,2 por ciento, té al 1 por ciento y aguadestilada (control). Se colocaron a 37°C y se extrajeron muestras de 20 μl a luego de 30 min, 90 min y 20 hs. Se dosaron proteínas totales utilizando el método de Lowry y por electroforesis(SDS-Page 12 por ciento). Se determinaron bandas de proteínassolubles. Los resultados se analizaron por Anova En el analisis químico, de las corridas electroforéticas de proteínaspulpares bovinas se evidenció que tanto el hipoclorito de sodio en ambas concentraciones como el hidróxido de calcio producen desnaturalización de proteínas. No se demuestra acción solvente con clorhexidina, té y agua destilada.

Comportamento da polpa dental após pulpotomia e aplicaçäo de trifosfato de adenosina, hidróxido de cálcio e combinaçäo de ambos: estudo histológico em dentes humanos / Behaviour of dental pulps after pulpotomy and application of adenosin three-phosphate, calcium hydroxide and both combination: histological study in human teeth

A finalidade desta pesquisa foi verificar o comportamento da polpa dentária após pulpotomia e proteçäo do remanescente pulporradicular com os seguintes materiais: trifosfato de adenosina e hidróxido de cálcio com e sem tratamento prévio com trifosfato de adenosina. Foram utilizados 80 dentes pré-molares de pacientes com idade de 10 a 16 anos. Decorridos períodos de observaçäo de 7 e 40 dias, os dentes foram extraídos e submetidos à análise radiográfica e histológica. Com base nos resultados obtidos as condiçöes experimentais em que foi realizado este trabalho, pôde-se concluir que: Em relaçäo à análise histopatológica: - o ATP puro se mostrou como um material irritante ao tecido pulpar; - o hidróxido de cálcio associado ou näo às soluçöes de ATP foram bem tolerados pelo tecido pulpar; - o processo de reparo pulpar foi acelerado quando utilizada a soluçäo de ATP näo-tamponada, previamente ao hidróxido de cálcio...