Evaluation of two mineral trioxide aggregate compounds as pulp-capping agents in human teeth

Aim: The present randomized, controlled prospective study evaluated the histomorphological response of human dental pulps capped with two grey mineral trioxide aggregate (MTA) compounds. Methodology: Pulp exposures were performed on the occlusal floor of 40 human permanent pre-molars. The pulp was capped either with ProRoot (Dentsply) or MTA-Angelus (Angelus) and restored with zinc oxide eugenol cement. After 30 and 60 days, teeth were extracted and processed for histological examination and the effects on the pulp were scored. The data were subjected to Kruskal-Wallis and Conover tests (α = 0.05). Results: In five out of the 40 teeth bacteria were present in pulp tissue. No significant difference was observed between the two materials (P > 0.05) in terms of overall histological features (hard tissue bridge, inflammatory response, giant cells and particles of capping materials). Overall, 94% and 88% of the specimens capped with MTA-Angelus and ProRoot, respectively, showed either total or partial hard tissue bridge formation (P > 0.05). Conclusions: Both commercial materials ProRoot (Dentsply) and MTA-Angelus (Angelus) produced similar responses in the pulp when used for pulp capping in intact, caries-free teeth. © 2009 International Endodontic Journal.

Influence of the coloring agent concentration on bleaching gel and pulp chamber temperatures during dental bleaching

This study evaluated the Influence of the coloring agent concentration on the temperature of the gel layer and pulp chamber during dental bleaching with an LED/laser light source. Ten human incisors and a digital thermometer with K-type thermocouples were used. Using a high-speed spherical diamond bur, endodontic access was gained through openings on the lingual faces until pulp chamber was exposed. One end of the thermocouple was placed on the labial surface (immersed in bleaching gel) and the other end in the pulp chamber. The same 10 specimens were used in the 12 groups, according to the type and concentration of bleaching gel. Each bleaching gel was used in four different concentrations: manipulated without coloring, with normal quantity recommended by the manufacturer, with double the recommended amount of coloring, and with triple the recommended amount of coloring. The temperature rise was measured every 30 seconds for three minutes with a K-type thermocouple. The data were analyzed by ANOVA to examine the concentration and type of bleaching gel. This test was followed by Tukey's test, which was performed Independently for the gel at the labial surface and the pulp chamber (a = 5%). For both surfaces, values of p = 0.00 were obtained for all factors and for the Interaction between them. The varying concentrations of coloring agent produced statistically significant differences in terms of temperature increase for both the gel layer and the pulp chamber during activation.

Response of human dental pulp to calcium hydroxide paste preceded by a corticosteroid/antibiotic dressing agent

Aim: To evaluate the treatment with corticosteroid/antibiotic dressing in pulpotomy with calcium hydroxide. Methods: Forty-six premolars were pulpotomized and randomly assigned into 3 groups. In Group I pulpal wound was directly capped with calcium hydroxide, and Group II and Group III received corticosteroid/antibiotic dressing for 10 min or 48 h, respectively, before pulp capping. Teeth were processed for histological analysis after 7, 30 or 60 days to determine inflammatory cell response, tissue disorganization, dentin bridge formation and presence of bacteria. Attributed scores were analyzed by Kruskal-Wallis and Mann-Whitney tests (α=0.05). Results: On the 7th day, all groups exhibited dilated and congested blood vessels in the tissue adjacent to pulpal wound. The inflammatory cell response was significantly greater in Group III (p<0.05). On the 30th day, in all groups, a thin dentin matrix layer was deposited adjacent to the pulpal wound and a continuous odontoblast-like cell layer underlying the dentin matrix was observed. On the 60th day, all groups presented a thick hard barrier characterized by an outer zone of dystrophic calcification and an inner zone of tubular dentin matrix underlined by a defined odontoblast-like cell layer. Conclusions: Within the limitations of present study, considering that the treatment was performed in healthy teeth, it may be concluded that the use of a corticosteroid/antibiotic dressing before remaining tissue protection with calcium hydroxide had no influence on pulp tissue healing.

Evaluation of the dentin-pulp complex after cavity preparation with ultrasonic diamond tip

The aim of this paper was to compare the dentin-pulp complex response to cavity preparation in human teeth using ultrasonic chemical vapor deposition (CVD) diamond tip and high-speed diamond bur. Class V buccal cavities were randomly prepared in 40 premolars from 14 patients aged 11 to 15 years. The cutting time was recorded and the cavities had the axial walls protected with gutta-percha and were filled with glass ionomer cement. The teeth were extracted at intervals of 0, 5, 10 and 20 days, and were decalcified, sectioned and stained by Hematoxylin & Eosin, Masson's Trichrome and Brown & Brenn techniques. The inflammatory response and cell disorganization were blindly evaluated by two examiners. The remaining dentin thickness (RDT) was measured by a linear scale using computer software. Statistical analysis by one-way ANOVA showed no statistically significant difference (P≤0.05) among the cavities prepared with either type of instrument, with mean RDT of 1132.50 mm. Cutting time and the pulp-dentin complex responses were analyzed statistically by Kruskal-Wallis and Dunn tests (P≤0.05). The ultrasonic CVD diamond tip took 5 times longer to prepare the cavities and there were no typical inflammatory pulp responses in cavities prepared with either type of cutting instrument, only mild to moderate cell disorganization was present. Even taking longer to cut the dental substrate, the ultrasonic CVD diamond tip produced similar pulp response compared to the conventional high-speed diamond bur.

Pulp tissue dissolution when the use of sodium hypochlorite and EDTA alone or associated

Purpose: The aim of the present study was to evaluate the tissue dissolving capacity of various concentrations of sodium hypochlorite either alone or in combination with 17% EDTA. Methods: Eighty bovine pulp fragments were prepared, and their weight was determined using a precision balance. Each pulp fragment was immersed for 2 hours in a solution/mixture that was based on the following groups: G1-saline solution; G2-0.5% NaOCl; G3-1.0% NaOCl; G4-2.5% NaOCl; G5-17% EDTA; G6-0.5% NaOCl+17% EDTA; G7-1.0% NaOCl+ 17% EDTA; and G8-2.5% NaOCl+17% EDTA. The final weight was measured, and the weight loss was calculated. A statistical analysis was performed using either the Student's t-test for paired samples or an ANOVA and Tukey tests (P<0.05 was considered to be significant). Results: We measured a significant difference between the sample weight before and after treatment for each of the tested groups (P<0.05). The 2.5% sodium hypochlorite solution (G4) completely dissolved the pulp tissue within the test period. NaOCl+EDTA was less effective than sodium hypochlorite alone at dissolving the pulp tissue (P<0.05), and EDTA alone (G5) did not markedly dissolve the pulp tissue. Conclusion: Using EDTA together with NaOCl reduced the tissue dissolving properties compared with NaOCl alone, regardless of the concentration of NaOCl that was used. © 2011 Só et al.; licensee EDIPUCRS.

Shelf Life of Fresh and Pasteurized Organic Passion Fruit (Passiflora Edulis F. Flavicarpa Deg.) Pulp

The shelf life of the organic passion fruit pulp, both fresh and pasteurized at 70C and 90C and stored under refrigeration, was evaluated. The heat treatment did not affect the sensory and physicochemical characteristics of the pasteurized pulps when compared with the fresh pulp, except for the ascorbic acid content. The pulps were also microbiologically safe. The pulps pasteurized at 70 and 90C were suitable for consumption for a minimum shelf-life period of 207 days of storage under refrigeration and for the fresh pulp it was attributed a shelf-life period of 60 to 90 days. The pulp pasteurized at 70C showed higher acceptance scores for all the attributes and purchase intention scores, suggesting a more stable behavior and higher sensory quality. Practical Applications: This work intended to evaluate the influence of the minimum pasteurization on the sensory acceptance and microbiological and physicochemical characteristics of the organic passion fruit pulp stored under refrigeration, with the aim to identify the shelf life. Heat treatment is one of the processes used for food preservation. Lower pasteurization temperature than that used by the Brazilian industries and storage under refrigeration showed to be appropriate for passion fruit pulp quality. In this way, the microbiological, physicochemical and sensory features of passion fruit were preserved. This work can be used as a reference for passion fruit pasteurization, which is able to increase the shelf life of this fruit while preserving its desirable original features. Journal Compilation © 2012 Wiley Periodicals, Inc.

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

Objectives: The clinical translation of stem cell-based Regenerative Endodontics demands further development of suitable injectable scaffolds. Puramatrix™ is a defined, self-assembling peptide hydrogel which instantaneously polymerizes under normal physiological conditions. Here, we assessed the compatibility of Puramatrix™ with dental pulp stem cell (DPSC) growth and differentiation. Methods: DPSC cells were grown in 0.05-0.25% Puramatrix™. Cell viability was measured colorimetrically using the WST-1 assay. Cell morphology was observed in 3D modeling using confocal microscopy. In addition, we used the human tooth slice model with Puramatrix™ to verify DPSC differentiation into odontoblast-like cells, as measured by expression of DSPP and DMP-1. Results: DPSC survived and proliferated in Puramatrix™ for at least three weeks in culture. Confocal microscopy revealed that cells seeded in Puramatrix™ presented morphological features of healthy cells, and some cells exhibited cytoplasmic elongations. Notably, after 21 days in tooth slices containing Puramatrix™, DPSC cells expressed DMP-1 and DSPP, putative markers of odontoblastic differentiation. Significance: Collectively, these data suggest that self-assembling peptide hydrogels might be useful injectable scaffolds for stem cell-based Regenerative Endodontics. © 2012 Academy of Dental Materials.

Effect of fluoride-treated enamel on indirect cytotoxicity of a16% carbamide peroxide bleaching gel to pulp cells

The aim of this study was to evaluate the possibility of fluoride solutions applied to enamel to protect pulp cells against the trans-enamel and transdentinal cytotoxicity of a 16% carbamide peroxide (CP) bleaching gel. The CP gel was applied to enamel/ dentin discs adapted to artificial pulp chambers (8 h/day) during 1, 7 or 14 days, followed by fluoride (0.05% or 0.2%) application for 1 min. The extracts (culture medium in contact with dentin) were applied to MDPC-23 cells for 1 h, and cell metabolism (MTT assay), alkaline phosphatase (ALP) activity and cell membrane damage (flow cytometry) were analyzed. Knoop microhardness of enamel was also evaluated. Data were analyzed statistically by ANOVA and Kruskal-Wallis tests (a=0.05). For the MTT assay and ALP activity, significant reductions between the control and the bleached groups were observed (p<0.05). No statistically significant difference occurred among bleached groups (p>0.05), regardless of fluoride application or treatment days. Flow cytometry analysis demonstrated 30% of cell membrane damage in all bleached groups. After 14 days of treatment, the fluoride-treated enamel presented significantly higher microhardness values than the bleached-only group (p<0.05). It was concluded that, regardless of the increase in enamel hardness due to the application of fluoride solutions, the treated enamel surface did not prevent the toxic effects caused by the 16% CP gel to odontoblast-like cells.

CCL3 and CXCL12 production in vitro by dental pulp fibroblasts from permanent and deciduous teeth stimulated by Porphyromonas gingivalis LPS

Objective: The aim of this study was to compare the production of the chemokines CCL3 and CXCL12 by cultured dental pulp fibroblasts from permanent (PDPF) and deciduous (DDPF) teeth under stimulation by Porphyromonas gingivalis LPS (PgLPS). Material and Methods: Primary culture of fibroblasts from permanent (n=3) and deciduous (n=2) teeth were established using an explant technique. After the fourth passage, fibroblasts were stimulated by increasing concentrations of PgLPS (0 - 10 pg/mL) at 1, 6 and 24 h. The cells were tested for viability through MTT assay, and production of the chemokines CCL3 and CXCL12 was determined through ELISA. Comparisons among samples were performed using One-way ANOVA for MTT assay and Two-way ANOVA for ELISA results. Results: Cell viability was not affected by the antigen after 24 h of stimulation. PgLPS induced the production of CCL3 by dental pulp fibroblasts at similar levels for both permanent and deciduous pulp fibroblasts. Production of CXCL12, however, was significantly higher for PDPF than DDPF at 1 and 6 h. PgLPS, in turn, downregulated the production of CXCL12 by PDPF but not by DDPF. Conclusion: These data suggest that dental pulp fibroblasts from permanent and deciduous teeth may present a differential behavior under PgLPS stimulation.

Pulp fruit added to culture medium for in vitro orchid development

As an additive in in vitro culture media, fruits have a great potential for facilitating economical orchid production because of lower technology requirements and the ease of obtaining raw materials to formulate culture media. We studied the in vitro growth of Cattleya bicolor Lindl. grown in a simplified culture medium supplemented with different kinds of fruit pulp. The experimental design was completely randomised, with eight seedlings per replication and ten replications per treatment, for a total of 80 seedlings per treatment. The culture medium was made using 150 g L -1 of pulp (without peel or seed) from the following fruits: ripe Santa Cruz tomatoes (Solanum lycopersicum L.), dwarf bananas (Musa cavendishii L.) of intermediate ripeness, light green chayote (Sechium edule (Jacq.) Sw), ripe papaya (Carica papaya L.) or green coconut (Cocos nucifera L.).The treatment control was MS 50 %. The treatments and the control were kept in a growth chamber for seven months before evaluating seedling survival percentage, shoot height, number of leaves, rooting percentage, root number, root length and dry masses of shoot and roots. The highest percentages of seedling survival were obtained using MS 50 %, banana and coconut medium. The seedling survival and rooting percentages illustrate that it is possible to emphasise the culture medium MS 50% and the culture medium supplemented with coconut on the most traditional culture medium with banana or tomato pulp. For the in vitro development of Cattleya bicolor Lindl., a simplified culture medium supplemented with coconut pulp is the most suitable for use as an alternative to MS 50%. A simplified culture medium supplemented with papaya pulp is not recommended for the in vitro development of Cattleya bicolor Lindl.

Physicochemical and bioactive properties of Hymenaea courbaril L. pulp and seed lipid fraction

This study aimed to assess the nutritional composition of the fruit and the physicochemical and bioactive properties of jatoba (Hymenaea courbaril L.) pulp and seed oils. The lipid content of both fractions was below 6%. There was a significant presence of minerals, especially, sodium, potassium and phosphorus. The main macronutrient in pulp and seed was crude fiber, and considerable amounts of Vitamin C, 51.87 and 121.45. mg/100. g respectively, were found. The physicochemical properties demonstrated the good quality of the oils. The oxidative stability index was influenced by the composition of fatty acids reaching a value of 45.97. h for the jatoba pulp oil. The most abundant bioactive compounds were α-tocopherol (886.37 and 993.63. mg/kg) and β-sitosterol (61.83 and 91.09. mg/kg) for pulp and seed oils, respectively. Among the unsaturated fatty acids in the pulp, the oleic (46.09%) and linolenic acid (14.54%) stood out. The pulp and seed oils can be considered a valuable source for new industrial, cosmetic and pharmaceutical products. © 2013 Elsevier B.V.

Effect of pectin extracted from citrus pulp on digesta characteristics and nutrient digestibility in broilers chickens

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The Number of Bleaching Sessions Influences Pulp Tissue Damage in Rat Teeth

Introduction: Hydrogen peroxide tooth bleaching is claimed to cause alterations in dental tissue structures. This study investigated the influence of the number of bleaching sessions on pulp tissue in rats. Methods: Male Wistar rats were studied in 5 groups (groups 1S-5S) of 10 each, which differed by the number (1-5) of bleaching sessions. In each session, the animals were anesthetized, and 35% hydrogen peroxide gel was applied to 3 upper right molars. Two days after the experimental period, the animals were killed, and their jaws were processed for light microscope evaluation. Pulp tissue reactions were scored as follows: 1, no or few inflammatory cells and no reaction; 2, <25 cells and a mild reaction; 3, between 25 and 125 cells and a moderate reaction; and 4, 125 or more cells and a severe reaction. Results from each experimental group were compared between groups and within groups to the corresponding unbleached upper left molars and analyzed for significant differences using the Kruskal-Wallis test (P < .05). Results: All tissue sections showed significant bleaching-induced changes in the dental pulp. After 1 bleaching session, necrotic tissue in the pulp horns and underlying inflammatory changes were observed. The extent and intensity of these changes increased with the number of bleaching sessions. After 5 sessions, the changes included necrotic areas in the pulp tissue involving the second third of the radicular pulp and intense inflammation in the apical third. Conclusions: The number of bleaching sessions directly influenced the extent of pulp damage. © 2013 American Association of Endodontists.

Isolamento de leveduras fermentadoras de pentoses e suas aplicações na produção de xilitol e etanol a partir do licor negro proveniente do processo Kraft de extração da celulose

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Aproveitamento de resíduos da indústria de celulose e papel em argamassa mista de revestimento interno

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)