NPY Y1 and VPAC1 receptor expression in human dental pulps

Neuropeptides such as neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP) have been shown by our research group to be present in human dental pulp tissue. Neuropeptides cannot cross cell membranes and therefore to exert their biological effects they must bind to selected receptors on the surface of target cell membranes. However, the expression of receptor proteins for NPY and/or VIP have yet to be reported in human pulp tissue. The presence of neuropeptide receptors can be conveniently determined by Western blotting using specific anti-receptor antibodies. Objectives: The aim of this work was to identify the presence of the NPY Y1 receptor and the VIP receptor VPAC1 in human dental pulp tissue from both intact and carious teeth using Western blotting. Methods: Pulp tissue was collected from both intact and carious teeth and membrane preparations from these tissues were then subject to sodium dodecyl sulphate gel electrophoresis (SDS-PAGE), transferred to nitrocellulose and probed with specific antibodies to either the NPY Y1 receptor or the VPAC1 receptor. Results: Individual Western blotting experiments revealed the presence of immunoreactive bands corresponding to the known molecular weights of the NPY Y1 and VPAC1 receptor proteins in both intact and carious pulp samples. Conclusions: Demonstration of the presence of NPY Y1 and VPAC1 receptor protein expression in pulpal tissue from intact and carious teeth provides further support for the roles of these neuropeptides in pulpal health and disease.

Vasoactive Intestinal Polypeptide (VIP) in Human Dental Pulps

Pulpal innervation is not exclusively sensory and there are potential roles for other neuropeptides such as vasoactive intestinal polypeptide (VIP) in pulpal health and disease. In the systemic circulation VIP relaxes vascular smooth muscles leading to vasodilatation. It has been shown that VIP fibres are associated with pulpal blood vessels and therefore VIP may mediate vasoactivity in the dental pulp. A growing body of evidence has now demonstrated that an additional major physiological role of VIP is to act as a survival factor. In order to gain a better understanding of the role of neuropeptides in the caries process it is of interest to specifically examine a role for VIP. Objectives: The aim of the present study was to determine the levels of VIP in carious (moderately carious and grossly carious) compared with non-carious teeth. Methods: A total of 68 teeth were included in the study (22 non-carious, 20 moderately carious and 26 grossly carious). VIP was measured in all samples using a sensitive and specific radioimmunoassay. Results: The mean concentration of VIP in the pulps of non-carious teeth was 7.69 ng/g (9.41 SD) compared to 14.93 ng/g (15.58 SD) in carious teeth. Pair-wise comparisons of VIP levels using Tukey’s test showed statistically significant differences in VIP expression between non-carious and moderately carious teeth (p=0.002) and between moderately and grossly carious teeth, (p=0.002). Conclusion: The significantly increased levels of VIP in moderately carious pulps compared with either non-carious or grossly carious pulps may suggest a role for VIP as a protective or survival factor.

Radioimmunoassay Quantitation of Neuropeptide Y (NPY) in Human Dental Pulps

Neuropeptide Y (NPY) is a 36 amino acid peptide that is abundantly expressed in both the central and peripheral nervous systems. NPY has previously been shown to be present in human dental pulp although its exact role in pulpal health and disease remains to be fully elucidated. In addition to serving a neurotransmitter role, NPY may also have a role in modulating the pulpal response to injury and inflammation. Indeed NPY is known to be a potent vasoconstrictor in a range of tissues. Recent work by our research group has demonstrated changes in sensory neuropeptide levels measured by radioimmunoassay (RIA) in healthy and carious teeth. In addition to elevated levels of sensory neuropeptides, it is also possible that the carious process is associated with increased levels of autonomic neuropeptides such as NPY. Objectives: The aim of the present study was to undertake a comprehensive quantitative RIA analysis of NPY expression in human dental pulps from carious and non-carious teeth. Methods: A total of 22 non-carious and 46 carious teeth were included in the study. NPY was measured in all samples using RIA. Briefly, the RIA system consisted of a total volume of 400 ul, comprising 100 ul anti-NPY antibody (Peninsula Laboratories), 200 ul human NPY synthetic standard or pulp sample, and 100 ul of 125I-labelled NPY as radioactive tracer. Results: The mean concentration of NPY in non-carious teeth was found to be 4.28 ng/g (4.34 SD) compared to 9.57 ng/g (9.39 SD) in carious teeth. Using ANOVA the difference in NPY levels between the non-carious group and the carious group was found to be statistically significant (p= 0.003). Conclusion: The significant increase in the levels of NPY in carious dental pulps reported in this study provides evidence for a role for NPY in the pulpal response to caries.

Brazilian fruit pulps as functional foods and additives: Evaluation of bioactive compounds

Eight tropical fruit pulps from Brazil were simultaneously characterised in terms of their antioxidant and antimicrobial properties. Antioxidant activity was screened by DPPH radical scavenging activity (126–3987 mg TE/100 g DW) and ferric reduction activity power (368–20819 mg AAE/100 g DW), and complemented with total phenolic content (329–12466 mg GAE/100 g DW) and total flavonoid content measurements (46–672 mg EE /100 g DW), whereas antimicrobial activity was tested against the most frequently found food pathogens. Acerola and açaí presented the highest values for the antioxidant-related measurements. Direct correlations between these measurements could be observed for some of the fruits. Tamarind exhibited the broadest antimicrobial potential, having revealed growth inhibition of Pseudomonas aeruginosa. Escherichia coli, Listeria monocytogenes, Salmonella sp. and Staphylococcus aureus. Açaí and tamarind extracts presented an inverse relationship between antibacterial and antioxidant activities, and therefore, the antibacterial activity cannot be attributed (only) to phenolic compounds.

SEM Study of Apical Morphological Alterations in Primary Teeth with Vital and Necrotic Pulps

This study evaluated, by SEM, the morphology of human primary teeth roots. Twenty-four teeth were divided into 3 groups: pulp vitality (group I) and pulp necrosis without (group II) and with apical periodontitis (group III). Roots were analyzed by the presence of periodontal ligament (PDL) fibers and resorption areas. In groups I and II, presence of PDL fibers and absence of resorption were observed in all cases (100%), while all specimens (100%) of group III showed no PDL fibers and resorption areas. In conclusion, there are morphological differences in the apical region of primary teeth with different pulpal and periapical pathologies.

Biofilm on the apical region of roots in primary teeth with vital and necrotic pulps with or without radiographically evident apical pathosis

Aim To evaluate, by scanning electron microscopy (SEM), the presence of biofilms on the external surfaces of the apical third of roots of human primary teeth with vital or necrotic pulps with and without radiographically evident periradicular pathosis. Methodology Eighteen teeth were selected: group I - normal pulp (n = 5), group II - pulp necrosis without radiographic evidence of periapical pathosis (n = 7) and group III - pulp necrosis with well-defined radiographic periapical pathosis (n = 6). After extraction, the teeth were washed with saline and immersed in 0.03 g mL(-1) trypsin solution for 20 min. The teeth were then washed in sodium cacodilate buffer and stored in receptacles containing modified Karnovsky solution. The teeth were sectioned, dehydrated in an ethanol series, critical-point dried with CO(2), sputter coated with gold and the external root surface in the apical third examined by SEM. Results In the teeth of groups I and II, the apical root surfaces were covered by collagen fibres, with no evidence of bacteria (100%). In the teeth of group III, the root apices had no collagen fibres but revealed resorptive areas containing microorganisms (cocci, bacilli, filaments and spirochetes) in all cases (100%). Conclusion Microorganisms organized as biofilms on the external root surface (extraradicular infection) were detected in primary teeth with pulp necrosis and radiographically visible periapical pathosis.

Comparative Histopathological Analysis of Human Pulps after Class I Cavity Preparation with a High-Speed Air-Turbine Handpiece or Er:YAG Laser

The purpose of this study was to comparatively evaluate the response of human pulps after cavity preparation with different devices. Deep class I cavities were prepared in sound mandibular premolars using either a high-speed air-turbine handpiece (Group 1) or an Er: YAG laser (Group 2). Following total acid etching and the application of an adhesive system, all cavities were restored with composite resin. Fifteen days after the clinical procedure, the teeth were extracted and processed for analysis under optical microscopy. In Group 1 in which the average for the remaining dentin thickness (RDT) between the cavity floor and the coronal pulp was 909.5 mu m, a discrete inflammatory response occurred in only one specimen with an RDT of 214 mu m. However, tissue disorganization occurred in most specimens. In Group 2 (average RDT = 935.2 mu m), the discrete inflammatory pulp response was observed in only one specimen (average RDT = 413 mu m). It may be concluded that the high-speed air-turbine handpiece caused greater structural alterations in the pulp, although without inducing inflammatory processes.

Hydrogen peroxide and supercritical carbon dioxide: a new bleaching stage for Eucalyptus kraft-O(2) pulps

Kraft pulp is currently bleached largely by the elemental chlorine free (ECF) technology with oxygen, chlorine dioxide, and hydrogen as active agents. This technology brought about significant environmental improvements in relation to standard processes based on chlorine gas and hypochlorite, but there is still need for further improvements. This study presents a novel environmentally friendly bleaching stage - the so-called `hydrogen peroxide in supercritical carbon dioxide`, P((SC-CO2)) - that can be adapted to current ECF bleaching processes, with preference in cases where hydrogen peroxide is already used. In this study, the P((SC-CO2)) stage was evaluated as a replacement to the last peroxide stage of the D(EP)DP bleaching sequence and to the first peroxide stage of the D(EP)DP sequence, for an oxygen delignified eucalypt kraft-O(2) pulp. The P((SC-CO2)) stage was run with 0.5% hydrogen peroxide, at 15% consistency, 70 degrees C, and 73 bar. The reaction time was 30 min. The performances of regular P stages and the new P((SC-CO2)) stage were compared. Promising results were observed with the DEP((SC-CO2))DP sequence; the P((SC-CO2)) decreased kappa number from 2.7 to 2.1, and the hexenuronic acid groups from 17.0 to 12.4 mmol kg(-1). The P((SC-CO2)) stage showed poor performance when applied in the D(EP)DP((SC-CO2)) sequence. It is concluded that the process presents potential but requires further optimization to improve selectivity and efficiency.

Attractiveness of Different Citrus Pulps to the Leaf-Cutting Ant Atta sexdens rubropilosa (Hymenoptera: Formicidae)

The most common control method Uses toxic baits consisted of dehydrated citrus pulp as carrier and attractant. However, the portion of the citrus fruit that is attractive to ants is still Unknown, despite its importance in chemical control. This study compared the attractiveness of different fruit parts of citrus pulps to Atta sexdens rubropilosa workers. Three treatments: pellets of industrial citrus pulp, albedo (mesocarp), and whole citrus pulp were offered randomly to ants and the removal of these substrates by workers was observed. Tie three pulps Were equally attractive to this species (F = 0.8033; p = 0.4633). Although the whole pulp included the epicarp, it was as attractive as the other treatments, possibly because, the material was heated during processing, eliminating any volatile substance that could repel ants.

Response of human pulps after professionally applied vital tooth bleaching

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Response of human pulps following acid conditioning and application of a bonding agent in deep cavities

Objectives. The aim of this in vivo study was to evaluate the human dental pulp response when a one-bottle adhesive system was applied on etched or unetched deep dentine.Methods. Eighteen class V deep cavity preparations were divided in three groups: group 1-total etching + two coats of single bond (SB) + composite resin (Z-100); group 2-enamel etching + two coats of SB + Z-100, group 3-cavity floor lined with a calcium hydroxide liner (Dycal) + acid-etching of enamel and lateral walls + two coats of SB + Z-100. Two teeth were used as intact control group. After 30 days the teeth were extracted and processed through H and E, Masson's trichrome and Brown and Brenn staining techniques.Results. Moderate inflammatory response, disorganization of pulp tissue, as well as, deposition of thin layer of reactionary dentin were observed in group 1 teeth in which the remaining dentin thickness (RDT) was less than 300 mum. These histological findings appear to be related to long resin tags formation and bonding agent diffusion through dentinal tubules. In group 2, slight inflammatory response was observed only in one tooth in which the RDT was 162 mum. In group 3, all the teeth showed normal histological characteristics which were similar to the intact control group. Presence of bacteria was not correlated with the intensity of pulpal response. The patients reported no symptoms during the experiment. Radiographic evaluation showed no periapical pathology for any of the teeth,Significance and conclusions. Acid-etched deep dentin (RDT less than 300 mum) lined with SB causes more intense pulpal response than unetched deep dentin. Based on the results observed in the present study and the conditions in which it was carried out, we recommend the application of a biocompatible liner before etching deep dentin and applying SB. (C) 2002 Academy of Dental Materials. Published by Elsevier B.V. Ltd. All rights reserved.

Response of human pulps capped with different self-etch adhesive systems

The aim of this study was to evaluate the response of human pulps capped with a calcium hydroxide hard-setting cement or with two-step self-etch adhesive systems. Pulp exposures were performed on the occlusal floor, and the bleeding control was performed with saline solution. The exposed pulp tissue was capped with Clearfil LB 2V (2V) or Clearfil SE Bond (SE) and restored with a composite resin. In control group, the pulpal wound was capped with Ca(OH)(2) cement and restored with Clearfil LB 2V or Clearfil SE Bond + composite resin. After 30 and 90 days, the teeth were extracted, processed for hematoxylin and eosin, and categorized in a histological score system. The pulpal response was worse for groups capped with the self-etch adhesive systems (2V and SE) in both periods of evaluation, when compared to their respective control groups at 90 days (p < 0.05). For both self-etch systems evaluated, the pulp tissue exhibited moderate to severe inflammatory cell infiltrate involving the coronal pulp with chronic abscesses. Dentin bridging was observed in a few specimens. For the calcium hydroxide groups, almost all specimens showed dentin bridge formation, with few scattered inflammatory cells and normal tissue below the pulp exposure site. Calcium hydroxide should be used as the material of choice for pulp capping, and the use of two-step self-etch adhesives for human pulp capping is contraindicated.

Comparative Histopathological Analysis of Human Pulps after Class I Cavity Preparation with a High-Speed Air-Turbine Handpiece or Er:YAG Laser

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fatty acids and bioactive compounds of the pulps and kernels of Brazilian palm species, guariroba (Syagrus oleraces), jeriva (Syagrus romanzoffiana) and macauba (Acrocomia aculeata)

BACKGROUND: Bioactive compounds are capable of providing health benefits, reducing disease incidence or favoring body functioning. There is a growing search for vegetable oils containing such compounds. This study aimed to characterize the pulp and kernel oils of the Brazilian palm species guariroba (Syagrus oleracea), jeriva (Syagrus romanzoffiana) and macauba (Acrocomia aculeata), aiming at possible uses in several industries.RESULTS: Fatty acid composition, phenolic and carotenoid contents, tocopherol composition were evaluated. The majority of the fatty acids in pulps were oleic and linoleic; macauba pulp contained 526 g kg(-1) of oleic acid. Lauric acid was detected in the kernels of all three species as the major saturated fatty acid, in amounts ranging from 325.8 to 424.3 g kg(-1). The jeriva pulp contained carotenoids and tocopherols on average of 1219 mu g g(-1) and 323.50 mg kg(-1), respectively.CONCLUSION: The pulps contained more unsaturated fatty acids than the kernels, mainly oleic and linoleic. Moreover, the pulps showed higher carotenoid and tocopherol contents. The kernels showed a predominance of saturated fatty acids, especially lauric acid. The fatty acid profiles of the kernels suggest that these oils may be better suited for the cosmetic and pharmaceutical industries than for use in foods. (C) 2011 Society of Chemical Industry