SEARCH · PubMed Health

Results for “DENTAL PULP”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources

PubMed2002

Three-dimensional wall structure and the innervation of dental pulp blood vessels.

The involvement of neural components in plasma extravasation and blood flow in the dental pulp has been established by pharmacological and physiological studies. We review here the segmental constitution of pulp vessels and the possible involvement of neural components in both the contractility and permeability of the pulp vessels from a morphological viewpoint. Six vascular segments can be identified based on the morphology of peri-endothelial cells, such as smooth muscle cells and pericytes. These are: muscular arterioles, terminal arterioles, precapillary arterioles, capillaries, postcapillary venules, and collecting or muscular venules. The perivascular nerve forms a mesh with numerous terminal varicosities, some of which attach directly to arteriolar smooth muscle cells. This mesh can be seen by scanning electron microscopy, and indicates the important role of neural components in regulating the pulpal circulation. After administering norepinephrine (0.2 mg/kg/dog), the surface texture of the smooth muscle cells of pulp arterioles reveals marked irregularities, which are correlated with arteriolar contraction. The pericytes in larger postcapillary venules (diameter 20 microm or larger) also show irregularities, whereas no changes are seen in the pericytes of either smaller postcapillary venules or capillaries. The intercellular spaces of pericytes in the postcapillary venules are wide enough for leukocytes to pass through, and the occasional extravasation of leukocytes through venule walls can be seen under electron microscopy. The microvessels of healthy human dental pulp react weakly to selectins, indicating that apparently healthy dental pulp may be weakly inflamed. In rat dental pulp, CGRP-immunoreactive nerves and nerve terminals containing many granular vesicles supply the postcapillary venules more densely than the arterioles, which suggests the involvement of postcapillary venules in neurogenic inflammation in the dental pulp.

Animals↗

PubMed2006

Histochemical and immunocytochemical study of hard tissue formation in dental pulp during the healing process in rat molars after tooth replantation.

Dental pulp is assumed to possess the capacity to elaborate both bone and dentin matrix under the pathological conditions following tooth injury. This study was undertaken to clarify the mechanism inducing bone formation in the dental pulp by investigating the pulpal healing process, after tooth replantation, by micro-computed tomography (mu-CT), immunocytochemistry for heat-shock protein (HSP)-25 and cathepsin K (CK), and histochemistry for both alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP). Under deep anesthesia, the upper right first molar of 4-week-old Wistar rats was extracted and immediately repositioned in the original socket. In control teeth at this age, the periphery of the coronal dental pulp showed intense ALP-positive and HSP-25-positive reactions, whereas there were no TRAP-positive or CK-positive cells. Tooth replantation weakened or terminated ALP-positive and HSP-25-positive reactions in the pulp tissue at the initial stages. At 3-7 days after operation, the ALP-positive region recovered from the root apex to the coronal pulp followed by HSP-25-positive reactions in successful cases showing tertiary dentin formation. In other cases, TRAP-positive and CK-positive cells appeared in the pulp tissue of the replanted tooth at postoperative days 5-10 and remained associated with the bone tissue after 12-60 days. Immunoelectron microscopy clearly demonstrated that CK-positive osteoclast-lineage cells made contact with mesenchymal cells with prominent nucleoli and well-developed cell organelles. These data suggest that the appearance of TRAP-positive and CK-positive cells is involved in the induction of bone tissue formation in dental pulp.

Acid Phosphatase↗

PubMedDate not supplied

Temperature changes in dental pulp associated with use of power grinding equipment on equine teeth.

OBJECTIVE: To quantify the temperature changes in the dental pulp associated with equine dental procedures using power grinding equipment. DESIGN: A matrix experimental design with replication on the same sample was followed to allow the following independent variables to be assessed: horse age (young or old), tooth type (premolar or molar), powered grinding instrument (rotating disc or die grinder), grinding time (15 or 20 seconds) and the presence or absence of water coolant. PROCEDURE: Sound premolar and molar teeth from a 6-year-old horse and a 15-year-old horse, which had been removed postmortem, were sectioned parallel to the occlusal plane to allow placement of a miniature thermocouple at the level of the dental pulp. The maximum temperature increase, the time taken to reach this maximum and the cooling time were measured (n=10 in each study). The teeth were placed in a vice and the instrument used on the tooth as per clinical situation. RESULTS: Significant differences were recorded for horse age (P < 0.001), instrument type (P < 0.001), grinding time (P < 0.001) and presence or absence of coolant (P < 0.001). There was no significant difference for tooth type. CONCLUSION: Thermal insult to the dental pulp from the use of power instruments poses a significant risk to the tooth. This risk can be reduced or eliminated by appropriate selection of treatment time and by the use of water irrigation as a coolant. The increased dentine thickness in older horses appears to mitigate against thermal injury from frictional heat.

Animals↗

PubMed2006

Effects of sonicated Prevotella intermedia, Fusobacterium nucleatum and Lactobacillus casei extracts on interleukin-8 production by human dental pulp cells.

The objective of this study was to determine the effects of Prevotella intermedia, Fusobacterium nucleatum and Lactobacillus casei on the production of IL-8 by human dental pulp cells. Human dental pulp cells from teeth of young patients (aged 18-25 years) were cultured and tested with sonicated P. intermedia ATCC 25611, F. nucleatum ATCC 25586 and L. casei ATCC 4646 extracts. IL-8 secreted into the culture supernatants were measured at 6, 12 and 24 hours using a quantitative sandwich enzyme immunoassay technique. Cell viability was evaluated using trypan blue exclusion technique. IL-8 production by human dental pulp cells increased significantly at 12 and 24 hours after exposure to P. intermedia and F. nucleatum, whereas L. casei extract exhibited low IL-8 production. The sonicated bacterial extracts did not significantly affect viability or total number of dental pulp cells.

Adolescent↗

PubMed1992

[Dental pulp in carious teeth].

Various etiologic causes lead to dental pulp changes ranging from inflammation to necrosis. The most frequent changes, however, are caused by bacterial activity and toxins from carious process. According to the opinion of various authors and on the basis of our investigations the conclusion can be made that all the forms of dental pulp changes can be developed as the sequela of the disease of supporting apparatus. Pathohistologic examination of dental pulp of cariously damaged teeth showed that the occurred changes are mostly the sequela of inflammation and regressive and progressive changes are found as well.

Adult↗

PubMed1992

[Demonstration of glutamate in primary sensory trigeminal neurons innervating dental pulp in rats].

Primary sensory trigeminal neurons supplying the dental pulp of incisors in rats were labelled by retrograde axonal transport. Using an auto-metallographic intensification procedure, 48 hrs. after injection of wheat-germ colloidal gold in the pulp, gold particles were detected in the cytoplasm of the neurons as black granulations. Glutamate was found in 45-60% of the neurons by submitting ganglion slices to an anti-glutamate immuno-serum revealed by immunocytochemistry. Among the neurons supplying the dental pulp of incisors by their peripheral process, 70% are Glu+, 30% Glu-. These observations suggest that the population of neurons supplying the dental pulp is not functionally homogeneous and that Glu- neurons use a different neurotransmitter. The coexistence of Glu+ and Glu- neurons could also indicate that glutamate expression is modulated during the life of these neurons.

Animals↗

PubMedDate not supplied

Histochemical identification of myosinlike substance in cells of the human dental pulp.

In this study of the human dental pulp, substances were found in smooth muscle cells, myoendothelial cells, fibroblasts, and odontoblastic processes that demonstrate staining and extraction characteristics identical to myosin in muscle. It is concluded that the myosinlike material similar to that found in cells elsewhere in the human also occurs in cells of the dental pulp.

Dental Pulp↗

PubMed2002

Effects of lead on the proliferation, protein production, and osteocalcin secretion of human dental pulp cells in vitro.

Teeth have been recognized as providing a useful long-term record of lead (Pb2+) uptake. However, information regarding the effects of lead on dental pulp tissue cells that foster dentinogenesis is scarce. This study investigated the effects of lead on dental pulp tissue using human dental pulp fibroblasts in vitro. Dental pulp cells from the teeth of young patients (aged 17-24 years) were cultured and subsequently treated with lead glutamate. It was shown that, in serum-free conditions, all the tested concentrations of lead (4.5 x 10(-5) M, 4.5 x 10(-6) M, and 4.5 x 10(-7) M) significantly increased pulpal cell proliferation. In the presence of 2% fetal bovine serum, increasing cell proliferation was observed only after exposure to a lead concentration of 4.5 x 10(-5) M. However, protein, procollagen type I, and osteocalcin productions were significantly decreased. The alteration of cell population and protein production of affected human dental pulp shown in this study are toxic effects of the lead.

Adolescent↗

PubMed2005

NF-kappaB activation in human dental pulp stem cells by TNF and LPS.

Post-natal human dental pulp stem cells (DPSCs) represent a unique precursor population in the dental pulp, which has multipotential and can regenerate a dentin/pulp-like structure. Because the dental pulp is frequently infected by oral bacteria due to dental decay, in this study, we examined whether lipopolysaccharide (LPS) and tumor necrosis factor (TNF) activated the immunologic transcription factor nuclear factor kappa B (NF-kappaB) in DPSCs. We found that both TNF and LPS activated the I-kappa B kinase complex (IKK) in DPSCs to induce the phosphorylation and degradation of IkappaBalpha, resulting in the nuclear translocation of NF-kappaB. Consistently, both TNF and LPS rapidly induced the expression of the NF-kappaB-dependent gene interleukin-8 (IL-8). However, unlike in monocytes, we found that LPS could not induce the phosphorylation of the NF-kappaB active subunit p65 in DPSCs. In summary, our studies suggest that DPSCs may be involved in immune responses during pulpal infection through activating NF-kappaB.

Blotting, Northern↗

PubMed1978

[Allergies and dental pulp (author's transl)].

A review of the articles dealing with allergy in the dental pulp is oppered. The dental pulp--furthermore when inflamed--showes antigens, lymphocyetes and plasmocytes, antibodies (IgG, IgA and IgE), mast-cells, histamine and possibly C3. However an hypersensitivity or allergy of immediate type elicited by circulating antibodies has never been demonstrated. In another way, two types of allergies of cellular type have been described in the dental pulp: graft rejection and contact hypersensitivity. Autoimmunity has also just been described.

Animals↗

PubMed2003

Perivascular niche of postnatal mesenchymal stem cells in human bone marrow and dental pulp.

Mesenchymal stem cell populations have previously been identified in adult bone marrow and dental pulp that are capable of regenerating the bone marrow and dental pulp microenvironments, respectively. Here we show that these stem cell populations reside in the microvasculature of their tissue of origin. Human bone marrow stromal stem cells (BMSSCs) and dental pulp stem cells (DPSCs) were isolated by immunoselection using the antibody, STRO-1, which recognizes an antigen on perivascular cells in bone marrow and dental pulp tissue. Freshly isolated STRO-1 positive BMSSCs and DPSCs were tested for expression of vascular antigens known to be expressed by endothelial cells (von Willebrand factor, CD146), smooth muscle cells, and pericytes (alpha-smooth muscle actin, CD146), and a pericyte-associated antigen (3G5), by immunohistochemistry, fluorescence-activated cell sorting (FACS), and/or immunomagnetic bead selection. Both BMSSCs and DPSCs lacked expression of von Willebrand factor but were found to be positive for alpha-smooth muscle actin and CD146. Furthermore, the majority of DPSCs expressed the pericyte marker, 3G5, while only a minor population of BMSSCs were found to be positive for 3G5. The finding that BMSSCs and DPSCs both display phenotypes consistent with different perivascular cell populations, regardless of their diverse ontogeny and developmental potentials, may have further implications in understanding the factors that regulate the formation of mineralized matrices and other associated connective tissues.

Adult↗

PubMed2005

[Study on enzymatically released human dental pulp cells with collagenase I in vitro].

OBJECTIVE: To investigate the alkaline phosphatase activity of enzymatically released human dental pulp cells with collagenase I in vitro. METHODS: We cultivated human dental pulp cells from connective tissue explants digested with collagenase I. Immunocytochemical staining was performed for characterization. When the subcultured cells grew in multilayers, the activity of alkaline phosphatase was examined by enzyme histochemical staining,and the ability of mineralization was detected. RESULTS: Cultures of human primary dental pulp cells became confluent after 15-20 days. Subcultured cells proliferated to multilayers in long-term cultures, and the staining of alkaline phosphatase was noted to be regional on culture slides. The pulp cells cultured in the presence of beta-glycerophosphate and L-ascorbic acid formed mineralization nodules. CONCLUSION: These results suggest that human dental pulp cells can be cultivated preferably from tissue explants digested with collagenase I in vitro. Enzyme histochemistry is useful for studying the biological behavior of dental pulp cells.

Alkaline Phosphatase↗

PubMed1999

cDNA cloning and sequencing of MH2 domain of Smad2 from human dental pulp cells.

OBJECTIVE: The purpose of this study was to clone and sequence the cDNA of MH2 domain of Smad2 from human dental pulp cells. METHODS: In this study, total RNA was isolated from primary cultured human dental pulp cells and reverse-transcribed into cDNA. The desired DNA product was obtained by nested PCR with 4 smad2 MH2 domain-specific primers. The segment was inserted into pBluescript II SK vector and the resulting plasmid was transformed into E. coli JM109. The double-strand cDNA of positive clone was sequenced by PE317-A automatic sequencing. RESULTS: cDNA of MH2 domain of Smad2 was obtained from human dental pulp cells. The sequence was consistent with that cloned from a human kidney cDNA library. No mutation was found. CONCLUSION: This study provides the first evidence of expression of smad2 in human dental pulp cells, and indicates that TGF-beta signaling may be mediated by Smad2 in human dental pulp cells. The cDNA cloned in pBluescript/S2MH2 could be used for further functional studies of Smad2 and MH2 domain in dental pulp cells.

Base Sequence↗

PubMed2004

Proliferation of dental pulp fibroblasts in response to thrombin involves mitogen-activated protein kinase signalling.

AIM: To examine the involvement of mitogen-activated protein kinases (MAPK) signalling on thrombin-stimulated human dental pulp fibroblasts (DPF). METHODOLOGY: Dental pulp fibroblasts were isolated from dental pulp connective tissue of third molars and expanded in vitro. Expression of thrombin receptors was analysed by RT-PCR, and cell proliferation was measured by 3[H]-thymidine incorporation assay. Phosphorylation levels of MAPK were determined by Western blot analysis, and alkaline phosphatase activity was measured to serve as a marker for odontogenic differentiation. Statistical analysis was performed by Student's t-test. RESULTS: Dental pulp fibroblasts express the thrombin receptors protease-activated receptor-1 (PAR-1), PAR-3 and PAR-4. Measurement of 3[H]-thymidine incorporation revealed a dose-dependent increase of DNA synthesis in response to thrombin treatment. The thrombin-induced mitogenic activity was decreased by the extracellular signal-regulated protein kinase (ERK) signalling inhibitor PD98059 (P < 0.05), and by SB203580 (P < 0.05), a p38 MAPK inhibitor. Western blot analysis demonstrated increased phosphorylation of ERK in DPF following stimulation with thrombin, while p38 MAPK and c-Jun NH2-terminal kinase (JNK) were not activated. Alkaline phosphatase activity of DPF remained unchanged upon incubation with thrombin. CONCLUSIONS: These results suggest that signalling via MAPK mediates the mitogenic activity of thrombin on DPF and may thus play a role during the early stages of pulp repair.

Adult↗

PubMed1993

An experimental study of osteogenesis by autografted dental pulp, periodontal ligament, and bone marrow in vivo.

Osteogenic activity of autografted dental pulp, periodontal ligament, and bone marrow of rat in vivo was investigated. Immunolocalization of ALPase in situ was also studied. One month after the transplantation, osteodentin was formed in all the dental pulp transplants (100%), bone or cementum like tissues were created in 20% of periodontal ligament transplants, and bone like tissues were in 20% of bone marrow transplants. After two months, osteodentin was produced in all the dental pulp transplants (100%) and bone like tissue were in 50% of both periodontal ligament and bone marrow transplants. Immunohistochemically, positive reactions to ALPase in situ were detected in cells just below the odontoblast layers in dental pulp, surface layers of alveolar bone in periodontal ligament, and endosteal membrane of bone marrow space. From these results, it was suggested that the cells of these three kinds of tissue can be termed osteogenic-fibroblasts in vivo.

Alkaline Phosphatase↗

PubMed1995

Evidence for the role of nitric oxide in the circulation of the dental pulp.

Many authors have studied the hemodynamics of the dental pulp; however, there are scarcely any data regarding the involvement of the L-arginine/nitric oxide pathway in the regulatory mechanism. Thus, we have examined the physiological effects of (1) NG-nitro-L-arginine as an inhibitor of nitric oxide synthesis and (2) the nitric oxide donor 3-morpholinosydnonimine on blood flow and vascular resistance in the canines of anesthetized cats to study the potential involvement of nitric oxide in the regulation of dental vascular homeostasis. Mean arterial blood pressure, heart rate, blood gases, pH, cardiac output, and tissue blood flow were determined prior to and 15 min after i.v. administration of either NG-nitro-L-arginine (30 mg/kg, n = 9) or 3-morpholinosydnonimine (1 mg/kg, n = 7). Blood flow was measured by radioactive-labeled microspheres. There were no significant differences in baseline parameters between the two groups of cats. The dental pulp blood flow decreased to 53 +/- 13% (p < 0.01) of the control level after NG-nitro-L-arginine administration, while it decreased only slightly (to 82 +/- 12%) after 3-morpholinosydnonimine administration. The dental pulp's vascular resistance increased to 367 +/- 69% (p < 0.01) of the control level after NG-nitro-L-arginine, while it decreased to 73 +/- 10% (p < 0.05) of control after 3-morpholinosydnonimine. We found that the L-arginine/nitric oxide pathway plays an important role in the regulation of pulpal blood circulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2000

Establishment and characterization of a culture system for enzymatically released rat dental pulp cells.

To establish a cell culture system that reflects the dentin formation in dental pulp tissue, we used dental pulp cells enzymatically isolated from rat incisor teeth. During the 20-day culture period, the cells exhibited various phenotypes of the odontoblast differentiation process, from the immature stage to the terminal mineralization stage. The cells began to form the mineralized nodules from day 10, and the nodules became larger by day 20. Alkaline phosphatase (ALP)-positive cells surrounded the mineralized nodules. The ALP activity in the cell layers was maximal on day 5, and gradually decreased to day 20. The calcium content in the cell layers was very low by day 10, and significantly increased from day 15. Sulfated glycosamino-glycans (GAGs) contained in the cell layers increased by day 15, but the content then decreased by day 20. The dental pulp cells produced a small amount of osteocalcin that was released into the culture medium by day 10, and the amount secreted increased markedly from day 15. The expression of osteocalcin and parathyroid hormone/parathyroid hormone-related peptide (PTH/PTHrP) receptor mRNA was evident as early as day 5, and the expression of each gradually increased with the number of days in culture. Dentin matrix protein (Dmp1) mRNA gene transcripts were identified by use of the reverse transcription polymerase chain reaction (RT-PCR) in the cells throughout the culture period. The present results demonstrate that this culture system is useful for studying the differentiation process of the odontoblast-like cells.

Alkaline Phosphatase↗

PubMed1989

Effects of insulin and parathyroid hormone on DNA synthesis and ornithine decarboxylase activity in cultured bovine dental pulp.

The effects of insulin and parathyroid hormone (PTH) on the proliferation of developing bovine dental pulp in an explant culture system were studied. Dental pulp explants were cultured on siliconized lens paper floating on the serum-free medium for up to 72 h. Ornithine decarboxylase (ODC) activity increased and reached a peak after 24 h. DNA synthesis increased continuously after a lag period of 24 h. Insulin (10 milliunits per ml) stimulated ODC activity 1.3-fold and DNA synthesis 1.5-fold. PTH alone (1 unit per ml) stimulated ODC activity in 1.7-fold, but did not affect DNA synthesis. PTH plus insulin caused greater increases in ODC activity and DNA synthesis in dental pulp explants than insulin alone (ODC, 2.6-fold; DNA, 3.7-fold). These results suggest that insulin and PTH are involved in the regulation of growth of dentinogenically active bovine dental pulp.

Animals↗