Comparison of Gingiva, Dental Pulp, and Periodontal Ligament Cells From the Standpoint of Mesenchymal Stem Cell Properties.

PubMed

Otabe, Koji; Muneta, Takeshi; Kawashima, Nobuyuki; Suda, Hideaki; Tsuji, Kunikazu; Sekiya, Ichiro

2012-01-01

The specific properties of mesenchymal stem cells (MSCs) in oral tissues still remain unknown though their existence has been previously reported. We collected gingiva, dental pulp, and periodontal ligament tissues from removed teeth and isolated MSCs. These MSCs were compared in terms of their yields per tooth, surface epitopes, and differentiation potentials by patient-matched analysis. For in vivo calcification analysis, rat gingival and dental pulp cells mounted on β-tricalcium phospateTCP were transplanted into the perivertebral muscle of rats for 6 weeks. Gingival cells and dental pulp cells showed higher yield per tooth than periodontal ligament cells (n=6, p<0.05). Yields of periodontal ligament cells were too low for further analysis. Gingival and dental pulp cells expressed MSC markers such as CD44, CD90, and CD166. Gingival and dental pulp cells obtained phenotypes of chondrocytes and adipocytes in vitro. Approximately 60% of the colonies of gingival cells and 40% of the colonies of dental pulp cells were positively stained with alizarin red in vitro, and both gingival and dental pulp cells were calcified in vivo. We clarified properties of MSCs derived from removed teeth. We could obtain a high yield of MSCs with osteogenic potential from gingiva and dental pulp. These results indicate that gingiva and dental pulp are putative cell sources for hard tissue regeneration.

Comparison of Gingiva, Dental Pulp, and Periodontal Ligament Cells From the Standpoint of Mesenchymal Stem Cell Properties

PubMed Central

Otabe, Koji; Muneta, Takeshi; Kawashima, Nobuyuki; Suda, Hideaki; Tsuji, Kunikazu; Sekiya, Ichiro

2012-01-01

The specific properties of mesenchymal stem cells (MSCs) in oral tissues still remain unknown though their existence has been previously reported. We collected gingiva, dental pulp, and periodontal ligament tissues from removed teeth and isolated MSCs. These MSCs were compared in terms of their yields per tooth, surface epitopes, and differentiation potentials by patient-matched analysis. For in vivo calcification analysis, rat gingival and dental pulp cells mounted on β-tricalcium phospateTCP were transplanted into the perivertebral muscle of rats for 6 weeks. Gingival cells and dental pulp cells showed higher yield per tooth than periodontal ligament cells (n=6, p<0.05). Yields of periodontal ligament cells were too low for further analysis. Gingival and dental pulp cells expressed MSC markers such as CD44, CD90, and CD166. Gingival and dental pulp cells obtained phenotypes of chondrocytes and adipocytes in vitro. Approximately 60% of the colonies of gingival cells and 40% of the colonies of dental pulp cells were positively stained with alizarin red in vitro, and both gingival and dental pulp cells were calcified in vivo. We clarified properties of MSCs derived from removed teeth. We could obtain a high yield of MSCs with osteogenic potential from gingiva and dental pulp. These results indicate that gingiva and dental pulp are putative cell sources for hard tissue regeneration. PMID:26858852

Characterization of stem and progenitor cells in the dental pulp of erupted and unerupted murine molars

PubMed Central

Balic, Anamaria; Aguila, H. Leonardo; Caimano, Melissa J.; Francone, Victor P.; Mina, Mina

2010-01-01

In the past few years there have been significant advances in the identification of putative stem cells also referred to as “mesenchymal stem cells” (MSC) in dental tissues including the dental pulp. It is thought that MSC in dental pulp share certain similarities with MSC isolated from other tissues. However, cells in dental pulp are still poorly characterized. This study focused on the characterization of progenitor and stem cells in dental pulps of erupted and unerupted mice molars. Our study showed that dental pulps from unerupted molars contain a significant number of cells expressing CD90+/CD45-, CD117+/CD45-, Sca-1+/CD45- and little if any CD45+ cells. Our in vitro functional studies showed that dental pulp cells from unerupted molars displayed extensive osteo-dentinogenic potential but were unable to differentiate into chondrocytes and adipocytes. Dental pulp from erupted molars displayed a reduced number of cells, contained higher percentage of CD45+ and lower percentage of cells expressing CD90+/CD45-, CD117+/CD45- as compared to unerupted molars. In vitro functional assays demonstrated the ability of a small fraction of cells to differentiate into odontoblasts, osteoblasts, adipocytes and chondrocytes. There was a significant reduction in the osteo-dentinogenic potential of the pulp cells derived from erupted molars compared to unerupted molars. Furthermore, the adipogenic and chondrogenic differentiation of pulp cells from erupted molars was dependent on a long induction period and infrequent. Based on these findings we propose that the dental pulp of the erupted molars contain a small population of multipotent cells, whereas the dental pulp of the unerupted molars does not contain multipotent cells but is enriched in osteo-dentinogenic progenitors engaged in the formation of coronal and radicular odontoblasts. PMID:20193787

TOOTH (The Open study Of dental pulp stem cell Therapy in Humans): Study protocol for evaluating safety and feasibility of autologous human adult dental pulp stem cell therapy in patients with chronic disability after stroke.

PubMed

Nagpal, Anjali; Kremer, Karlea L; Hamilton-Bruce, Monica A; Kaidonis, Xenia; Milton, Austin G; Levi, Christopher; Shi, Songtao; Carey, Leeanne; Hillier, Susan; Rose, Miranda; Zacest, Andrew; Takhar, Parabjit; Koblar, Simon A

2016-07-01

Stroke represents a significant global disease burden. As of 2015, there is no chemical or biological therapy proven to actively enhance neurological recovery during the chronic phase post-stroke. Globally, cell-based therapy in stroke is at the stage of clinical translation and may improve neurological function through various mechanisms such as neural replacement, neuroprotection, angiogenesis, immuno-modulation, and neuroplasticity. Preclinical evidence in a rodent model of middle cerebral artery ischemic stroke as reported in four independent studies indicates improvement in neurobehavioral function with adult human dental pulp stem cell therapy. Human adult dental pulp stem cells present an exciting potential therapeutic option for improving post-stroke disability. TOOTH (The Open study Of dental pulp stem cell Therapy in Humans) will investigate the use of autologous stem cell therapy for stroke survivors with chronic disability, with the following objectives: (a) determine the maximum tolerable dose of autologous dental pulp stem cell therapy; (b) define that dental pulp stem cell therapy at the maximum tolerable dose is safe and feasible in chronic stroke; and (c) estimate the parameters of efficacy required to design a future Phase 2/3 clinical trial. TOOTH is a Phase 1, open-label, single-blinded clinical trial with a pragmatic design that comprises three stages: Stage 1 will involve the selection of 27 participants with middle cerebral artery ischemic stroke and the commencement of autologous dental pulp stem cell isolation, growth, and testing in sequential cohorts (n = 3). Stage 2 will involve the transplantation of dental pulp stem cell in each cohort of participants with an ascending dose and subsequent observation for a 6-month period for any dental pulp stem cell-related adverse events. Stage 3 will investigate the neurosurgical intervention of the maximum tolerable dose of autologous dental pulp stem cell followed by 9 weeks of intensive task-specific rehabilitation. Advanced magnetic resonance and positron emission tomography neuro-imaging, and clinical assessment will be employed to probe any change afforded by stem cell therapy in combination with rehabilitation. Nine participants will step-wise progress in Stage 2 to a dose of up to 10 million dental pulp stem cell, employing a cumulative 3 + 3 statistical design with low starting stem cell dose and subsequent dose escalation, assuming that an acceptable probability of dose-limiting complications is between 1 in 6 (17%) and 1 in 3 (33%) of patients. In Stage 3, another 18 participants will receive an intracranial injection with the maximum tolerable dose of dental pulp stem cell. The primary outcomes to be measured are safety and feasibility of intracranial administration of autologous human adult DPSC in patients with chronic stroke and determination of the maximum tolerable dose in human subjects. Secondary outcomes include estimation of the measures of effectiveness required to design a future Phase 2/3 clinical trial. © 2016 World Stroke Organization.

Association between dental pulp stones and calcifying nanoparticles.

PubMed

Zeng, Jinfeng; Yang, Fang; Zhang, Wei; Gong, Qimei; Du, Yu; Ling, Junqi

2011-01-07

The etiology of dental pulp stones, one type of extraskeletal calcification disease, remains elusive to date. Calcifying nanoparticles (CNPs), formerly referred to as nanobacteria, were reported to be one etiological factor in a number of extraskeletal calcification diseases. We hypothesized that CNPs are involved in the calcification of the dental pulp tissue, and therefore investigated the link between CNPs and dental pulp stones. Sixty-five freshly collected dental pulp stones, each from a different patient, were analyzed. Thirteen of the pulp stones were examined for the existence of CNPs in situ by immunohistochemical staining (IHS), indirect immunofluorescence staining (IIFS), and transmission electron microscope (TEM). The remaining 52 pulp stones were used for isolation and cultivation of CNPs; the cultured CNPs were identified and confirmed via their shape and growth characteristics. Among the dental pulp stones examined in situ, 84.6% of the tissue samples staines positive for CNPs antigen by IHS; the corresponding rate by IIFS was 92.3 %. In 88.2% of the cultured samples, CNPs were isolated and cultivated successfully. The CNPs were visible under TEM as 200-400 nm diameter spherical particles surrounded by a compact crust. CNPs could be detected and isolated from a high percentage of dental pulp stones, suggesting that CNPs might play an important role in the calcification of dental pulp.

Expression of high mobility group box 1 in inflamed dental pulp and its chemotactic effect on dental pulp cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Xufang, E-mail: xufang.zhang@student.qut.edu.au; Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD 4059; Jiang, Hongwei, E-mail: jianghw@163.com

Highlights: • HMGB1 translocated from nucleus to cytoplasm during dental pulp inflammation. • HMGB1and its receptor RAGE were up-regulated in hDPCs under LPS stimulation. • HMGB1 enhanced hDPCs migration and induces cytoskeleton reorganization. • HMGB1 may play a critical role in dental pulp repair during inflamed state. - Abstract: High mobility group box 1 protein (HMGB1) is a chromatin protein which can be released extracellularly, eliciting a pro-inflammatory response and promoting tissue repair process. This study aimed to examine the expression and distribution of HMGB1 and its receptor RAGE in inflamed dental pulp tissues, and to assess its effects onmore » proliferation, migration and cytoskeleton of cultured human dental pulp cells (DPCs). Our data demonstrated that cytoplasmic expression of HMGB1 was observed in inflamed pulp tissues, while HMGB1 expression was confined in the nuclei in healthy dental pulp. The mRNA expression of HMGB1 and RAGE were significantly increased in inflamed pulps. In in vitro cultured DPCs, expression of HMGB1 in both protein and mRNA level was up-regulated after treated with lipopolysaccharide (LPS). Exogenous HMGB1 enhanced DPCs migration in a dose-dependent manner and induced the reorganization of f-actin in DPCs. Our results suggests that HMGB1 are not only involved in the process of dental pulp inflammation, but also play an important role in the recruitment of dental pulp stem cells, promoting pulp repair and regeneration.« less

Human dental pulp stem cells with highly angiogenic and neurogenic potential for possible use in pulp regeneration.

PubMed

Nakashima, Misako; Iohara, Koichiro; Sugiyama, Masahiko

2009-01-01

Dental caries is a common public health problem, causing early loss of dental pulp and resultant tooth loss. Dental pulp has important functions to sustain teeth providing nutrient and oxygen supply, innervation, reactionary/reparative dentin formation and immune response. Regeneration of pulp is an unmet need in endodontic therapy, and angiogenesis/vasculogenesis and neurogenesis are critical for pulp regeneration. Permanent and deciduous pulp tissue is easily available from teeth after extraction without ethical issues and has potential for clinical use. In this review, we introduce some stem cell subfractions, CD31(-)/CD146(-) SP cells and CD105(+) cells with high angiogenic and neurogenic potential, derived from human adult dental pulp tissue. Potential utility of these cells is addressed as a source of cells for treatment of cerebral and limb ischemia and pulp inflammation complete with angiogenesis and vasculogenesis.

A theranostic dental pulp capping agent with improved MRI and CT contrast and biological properties.

PubMed

Mastrogiacomo, S; Güvener, N; Dou, W; Alghamdi, H S; Camargo, W A; Cremers, J G O; Borm, P J A; Heerschap, A; Oosterwijk, E; Jansen, J A; Walboomers, X F

2017-10-15

Different materials have been used for vital dental pulp treatment. Preferably a pulp capping agent should show appropriate biological performance, excellent handling properties, and a good imaging contrast. These features can be delivered into a single material through the combination of therapeutic and diagnostic agents (i.e. theranostic). Calcium phosphate based composites (CPCs) are potentially ideal candidate for pulp treatment, although poor imaging contrast and poor dentino-inductive properties are limiting their clinical use. In this study, a theranostic dental pulp capping agent was developed. First, imaging properties of the CPC were improved by using a core-shell structured dual contrast agent (csDCA) consisting of superparamagnetic iron oxide (SPIO) and colloidal gold, as MRI and CT contrast agent respectively. Second, biological properties were implemented by using a dentinogenic factor (i.e. bone morphogenetic protein 2, BMP-2). The obtained CPC/csDCA/BMP-2 composite was tested in vivo, as direct pulp capping agent, in a male Habsi goat incisor model. Our outcomes showed no relevant alteration of the handling and mechanical properties (e.g. setting time, injectability, and compressive strength) by the incorporation of csDCA particles. In vivo results proved MRI contrast enhancement up to 7weeks. Incisors treated with BMP-2 showed improved tertiary dentin deposition as well as faster cement degradation as measured by µCT assessment. In conclusion, the presented theranostic agent matches the imaging and regenerative requirements for pulp capping applications. In this study, we combined diagnostic and therapeutic agents in order to developed a theranostic pulp capping agent with enhanced MRI and CT contrast and improved dentin regeneration ability. In our study we cover all the steps from material preparation, mechanical and in vitro characterization, to in vivo study in a goat dental model. To the best of our knowledge, this is the first time that a theranostic pulp capping material have been developed and tested in an in vivo animal model. Our promising results in term of imaging contrast enhancement and of induction of new dentin formation, open a new scenario in the development of innovative dental materials. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Vital Pulp Therapy—Current Progress of Dental Pulp Regeneration and Revascularization

PubMed Central

Zhang, Weibo; Yelick, Pamela C.

2010-01-01

Pulp vitality is extremely important for the tooth viability, since it provides nutrition and acts as biosensor to detect pathogenic stimuli. In the dental clinic, most dental pulp infections are irreversible due to its anatomical position and organization. It is difficult for the body to eliminate the infection, which subsequently persists and worsens. The widely used strategy currently in the clinic is to partly or fully remove the contaminated pulp tissue, and fill and seal the void space with synthetic material. Over time, the pulpless tooth, now lacking proper blood supply and nervous system, becomes more vulnerable to injury. Recently, potential for successful pulp regeneration and revascularization therapies is increasing due to accumulated knowledge of stem cells, especially dental pulp stem cells. This paper will review current progress and feasible strategies for dental pulp regeneration and revascularization. PMID:20454445

Functionalized scaffolds to control dental pulp stem cell fate

PubMed Central

Piva, Evandro; Silva, Adriana F.; Nör, Jacques E.

2014-01-01

Emerging understanding about interactions between stem cells, scaffolds and morphogenic factors has accelerated translational research in the field of dental pulp tissue engineering. Dental pulp stem cells constitute a sub-population of cells endowed with self-renewal and multipotency. Dental pulp stem cells seeded in biodegradable scaffolds and exposed to dentin-derived morphogenic signals give rise to a pulp-like tissue capable of generating new dentin. Notably, dentin-derived proteins are sufficient to induce dental pulp stem cell differentiation into odontoblasts. Ongoing work is focused on developing ways of mobilizing dentin-derived proteins and disinfecting the root canal of necrotic teeth without compromising the morphogenic potential of these signaling molecules. On the other hand, dentin by itself does not appear to be capable of inducing endothelial differentiation of dental pulp stem cells, despite the well known presence of angiogenic factors in dentin. This is particularly relevant in the context of dental pulp tissue engineering in full root canals, where access to blood supply is limited to the apical foramina. To address this challenge, scientists are looking at ways to use the scaffold as a controlled release device for angiogenic factors. The aim of this manuscript is to present and discuss current strategies to functionalize injectable scaffolds and customize them for dental pulp tissue engineering. The long-term goal of this work is to develop stem cell-based therapies that enable the engineering of functional dental pulps capable of generating new tubular dentin in humans. PMID:24698691

Electrophysiologic and functional evaluations of regenerated facial nerve defects with a tube containing dental pulp cells in rats.

PubMed

Sasaki, Ryo; Matsumine, Hajime; Watanabe, Yorikatsu; Takeuchi, Yuichi; Yamato, Masayuki; Okano, Teruo; Miyata, Mariko; Ando, Tomohiro

2014-11-01

Dental pulp tissue contains Schwann and neural progenitor cells. Tissue-engineered nerve conduits with dental pulp cells promote facial nerve regeneration in rats. However, no nerve functional or electrophysiologic evaluations were performed. This study investigated the compound muscle action potential recordings and facial functional analysis of dental pulp cell regenerated nerve in rats. A silicone tube containing rat dental pulp cells in type I collagen gel was transplanted into a 7-mm gap of the buccal branch of the facial nerve in Lewis rats; the same defect was created in the marginal mandibular branch, which was ligatured. Compound muscle action potential recordings of vibrissal muscles and facial functional analysis with facial palsy score of the nerve were performed. Tubulation with dental pulp cells showed significantly lower facial palsy scores than the autograft group between 3 and 10 weeks postoperatively. However, the dental pulp cell facial palsy scores showed no significant difference from those of autograft after 11 weeks. Amplitude and duration of compound muscle action potentials in the dental pulp cell group showed no significant difference from those of the intact and autograft groups, and there was no significant difference in the latency of compound muscle action potentials between the groups at 13 weeks postoperatively. However, the latency in the dental pulp cell group was prolonged more than that of the intact group. Tubulation with dental pulp cells could recover facial nerve defects functionally and electrophysiologically, and the recovery became comparable to that of nerve autografting in rats.

Comparison of the efficacy of a custom-made pulse oximeter probe with digital electric pulp tester, cold spray, and rubber cup for assessing pulp vitality.

PubMed

Dastmalchi, Nafiseh; Jafarzadeh, Hamid; Moradi, Saeed

2012-09-01

The ideal technique for the evaluation of pulp vitality should be noninvasive, painless, objective, reliable, and reproducible. To achieve this, the most routine tests are sensitivity tests. However, a major shortcoming with these tests is that they indirectly indicate pulp vitality by measuring a neural response. Pulse oximetry is a well-established oxygen saturation monitoring technique broadly used in medicine. However, its efficacy as the pulp vitality test should be evaluated. The aim of this study was to design and build a custom-made pulse oximeter dental probe and to evaluate its efficacy in comparison with electric pulp tester, cold spray, and a rubber cup in pulp vitality testing. Twenty-four single-canal mandibular premolars needing endodontic treatment were selected. The patients did not have systemic disease and did not consume drugs. Also, they had no clinically relevant signs of necrosis. The selected teeth were pulpally tested with 4 kinds of tests including pulse oximetry, the electric test, cold spray, and the rubber cup. After endodontic treatment of these teeth, which revealed the actual status of the pulp, the results were analyzed by the kappa test to show the efficacy of these tests. When comparing electric, cold, heat, and pulse oximeter tests with the gold standard, the kappa agreement coefficient was 18%, 18%, 14%, and 91%, respectively. The sensitivity of pulse oximetry, a rubber cup, electric test, and cold spray was 0.93, 0.60, 0.60, and 0.53, respectively. The specificity of these tests was 1.00, 0.55, 0.22, and 0.66, respectively. Pulp testing by using pulse oximetry is more reliable than the electric test, rubber cup, and cold spray. The custom-made pulse oximeter dental probe is an effective and objective method for pulp vitality assessment. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Idiopathic dental pulp calcifications in a tertiary care setting in South India.

PubMed

Satheeshkumar, P S; Mohan, Minu P; Saji, Sweta; Sadanandan, Sudheesh; George, Giju

2013-01-01

Dental pulp calcifications are unique and represent the dental pulp regenerative process. Dental pulp calcifications are sometimes routine findings in oral radiographs and may later serve as an important diagnostic criterion for a hidden aspect of systemic illness. The purpose of this study was to assess the patterns and prevalence of idiopathic dental pulp calcifications in a tertiary care setting in South India. A total of 227 patients were included in the study fulfilling the inclusion criteria. Age range of the study population was from 15 to 70 years. Teeth were examined under digital panoramic radiograph. The presence or absence of pulp stones was recorded. The presence of pulp stone were categorized according to the types classified as Type I, Type IA, Type II, Type IIA, Type II B, and Type III. The frequency of occurrence of pulp stones with sex, tooth type, dental arches, and types were compared with the types of calcification. Total no. of patients with pulpal calcification were 227 [females 133 (58.59%) and males 94 (41.40%)]. The most common type between both sexes was Type I (48%). Total no. of teeth with calcification was 697; maxilla (48%), mandible (52%). The prevalence of pulp stone was found to be higher in the molars in both the arches. Most no. of pulp stones are reported at the third and fourth decade of life. Idiopathic dental pulp calcifications are incidental radiographic findings of the pulp tissue and also may be an indicator of underlying disease.

Biomimetic extracellular matrix mediated somatic stem cell differentiation: applications in dental pulp tissue regeneration

PubMed Central

Ravindran, Sriram; George, Anne

2015-01-01

Dental caries is one of the most widely prevalent infectious diseases in the world. It affects more than half of the world's population. The current treatment for necrotic dental pulp tissue arising from dental caries is root canal therapy. This treatment results in loss of tooth sensitivity and vitality making it prone for secondary infections. Over the past decade, several tissue-engineering approaches have attempted regeneration of the dental pulp tissue. Although several studies have highlighted the potential of dental stem cells, none have transitioned into a clinical setting owing to limited availability of dental stem cells and the need for growth factor delivery systems. Our strategy is to utilize the intact ECM of pulp cells to drive lineage specific differentiation of bone marrow derived mesenchymal stem cells. From a clinical perspective, pulp ECM scaffolds can be generated using cell lines and patient specific somatic stem cells can be used for regeneration. Our published results have shown the feasibility of using pulp ECM scaffolds for odontogenic differentiation of non-dental mesenchymal cells. This focused review discusses the issues surrounding dental pulp tissue regeneration and the potential of our strategy to overcome these issues. PMID:25954205

Flow Line, Durafill VS, and Dycal toxicity to dental pulp cells: effects of growth factors

PubMed Central

Furey, Alyssa; Hjelmhaug, Julie; Lobner, Doug

2010-01-01

Introduction The objective was to determine the effects of growth factor treatment on dental pulp cell sensitivity to toxicity of two composite restoration materials, Flow Line and Durafill VS, and a calcium hydroxide pulp capping material, Dycal. Methods Toxicity of the dental materials to cultures of primary dental pulp cells was determined by the MTT metabolism assay. The ability of six different growth factors to influence the toxicity was tested. Results A 24 hour exposure to either Flow Line or Durafill VS caused approximately 40% cell death, while Dycal exposure caused approximately 80% cell death. The toxicity of Flow Line and Durafill VS was mediated by oxidative stress. Four of the growth factors tested (BMP-2, BMP-7, EGF, and TGF-β) decreased the basal MTT values while making the cells resistant to Flow Line and Durafill VS toxicity, except BMP-2 which made the cells more sensitive to Flow Line. Treatment with FGF-2 caused no change in basal MTT metabolism, prevented the toxicity of Durafill VS, but increased the toxicity of Flow Line. Treatment with IGF-I increased basal MTT metabolism and made the cells resistant to Flow Line and Durafill VS toxicity. None of the growth factors made the cells resistant to Dycal toxicity. Conclusions The results indicate that growth factors can be used to alter the sensitivity of dental pulp cells to commonly used restoration materials. The growth factors BMP-7, EGF, TGF-β, and IGF-I provided the best profile of effects, making the cells resistant to both Flow Line and Durafill VS toxicity. PMID:20630288

Epigenetic regulation in dental pulp inflammation

PubMed Central

Hui, T; Wang, C; Chen, D; Zheng, L; Huang, D; Ye, L

2016-01-01

Dental caries, trauma, and other possible factors could lead to injury of the dental pulp. Dental infection could result in immune and inflammatory responses mediated by molecular and cellular events and tissue breakdown. The inflammatory response of dental pulp could be regulated by genetic and epigenetic events. Epigenetic modifications play a fundamental role in gene expression. The epigenetic events might play critical roles in the inflammatory process of dental pulp injury. Major epigenetic events include methylation and acetylation of histones and regulatory factors, DNA methylation, and small non-coding RNAs. Infections and other environmental factors have profound effects on epigenetic modifications and trigger diseases. Despite growing evidences of literatures addressing the role of epigenetics in the field of medicine and biology, very little is known about the epigenetic pathways involved in dental pulp inflammation. This review summarized the current knowledge about epigenetic mechanisms during dental pulp inflammation. Progress in studies of epigenetic alterations during inflammatory response would provide opportunities for the development of efficient medications of epigenetic therapy for pulpitis. PMID:26901577

Regenerative Endodontics: Barriers and Strategies for Clinical Translation

PubMed Central

Kim, Sahng G.; Zhou, Jian; Ye, Ling; Cho, Shoko; Suzuki, Takahiro; Fu, Susan Y.; Yang, Rujing; Zhou, Xuedong; Mao, Jeremy J.

2014-01-01

SYNOPSIS Despite a great deal of enthusiasm and effort, regenerative endodontics has encountered substantial challenges towards clinical translation. Recent adoption by the American Dental Association (ADA) of evoked pulp bleeding in immature permanent teeth is an important step for regenerative endodontics. However, there is no regenerative therapy for the majority of endodontic diseases. Simple recapitulation of cell therapy and tissue engineering strategies that are under development for other organ systems has not led to clinical translation in regeneration endodontics. Dental pulp stem cells may appear to be a priori choice for dental pulp regeneration. However, dental pulp stem cells may not be available in a patient who is in need of pulp regeneration. Even if dental pulp stem cells are available autologously or perhaps allogeneically, one must address a multitude of scientific, regulatory and commercialization barriers, and unless these issues are resolved, transplantation of dental pulp stem cells will remain a scientific exercise, rather than a clinical reality. Recent work using novel biomaterial scaffolds and growth factors that orchestrate the homing of host endogenous cells represents a departure from traditional cell transplantation approaches and may accelerate clinical translation. Given the functions and scale of dental pulp and dentin, regenerative endodontics is poised to become one of the early biological solutions in regenerative dental medicine. PMID:22835543

Expression of Vesicular Glutamate Transporters VGLUT1 and VGLUT2 in the Rat Dental Pulp and Trigeminal Ganglion following Inflammation

PubMed Central

Hong, Jae Hyun; Kim, Yun Sook; Choi, So Young; Kim, Tae Heon; Cho, Yi Sul; Bae, Yong Chul

2014-01-01

Background There is increasing evidence that peripheral glutamate signaling mechanism is involved in the nociceptive transmission during pathological conditions. However, little is known about the glutamate signaling mechanism and related specific type of vesicular glutamate transporter (VGLUT) in the dental pulp following inflammation. To address this issue, we investigated expression and protein levels of VGLUT1 and VGLUT2 in the dental pulp and trigeminal ganglion (TG) following complete Freund’s adjuvant (CFA) application to the rat dental pulp by light microscopic immunohistochemistry and Western blot analysis. Results The density of VGLUT2− immunopositive (+) axons in the dental pulp and the number of VGLUT2+ soma in the TG increased significantly in the CFA-treated group, compared to control group. The protein levels of VGLUT2 in the dental pulp and TG were also significantly higher in the CFA-treated group than control group by Western blot analysis. The density of VGLUT1+ axons in the dental pulp and soma in the TG remained unchanged in the CFA-treated group. Conclusions These findings suggest that glutamate signaling that is mediated by VGLUT2 in the pulpal axons may be enhanced in the inflamed dental pulp, which may contribute to pulpal axon sensitization leading to hyperalgesia following inflammation. PMID:25290694

Expression of vesicular glutamate transporters VGLUT1 and VGLUT2 in the rat dental pulp and trigeminal ganglion following inflammation.

PubMed

Yang, Eun Sun; Jin, Myoung Uk; Hong, Jae Hyun; Kim, Yun Sook; Choi, So Young; Kim, Tae Heon; Cho, Yi Sul; Bae, Yong Chul

2014-01-01

There is increasing evidence that peripheral glutamate signaling mechanism is involved in the nociceptive transmission during pathological conditions. However, little is known about the glutamate signaling mechanism and related specific type of vesicular glutamate transporter (VGLUT) in the dental pulp following inflammation. To address this issue, we investigated expression and protein levels of VGLUT1 and VGLUT2 in the dental pulp and trigeminal ganglion (TG) following complete Freund's adjuvant (CFA) application to the rat dental pulp by light microscopic immunohistochemistry and Western blot analysis. The density of VGLUT2- immunopositive (+) axons in the dental pulp and the number of VGLUT2+ soma in the TG increased significantly in the CFA-treated group, compared to control group. The protein levels of VGLUT2 in the dental pulp and TG were also significantly higher in the CFA-treated group than control group by Western blot analysis. The density of VGLUT1+ axons in the dental pulp and soma in the TG remained unchanged in the CFA-treated group. These findings suggest that glutamate signaling that is mediated by VGLUT2 in the pulpal axons may be enhanced in the inflamed dental pulp, which may contribute to pulpal axon sensitization leading to hyperalgesia following inflammation.

Monitoring Notch Signaling-Associated Activation of Stem Cell Niches within Injured Dental Pulp

PubMed Central

Mitsiadis, Thimios A.; Catón, Javier; Pagella, Pierfrancesco; Orsini, Giovanna; Jimenez-Rojo, Lucia

2017-01-01

Dental pulp stem/progenitor cells guarantee tooth homeostasis, repair and regeneration throughout life. The decision between renewal and differentiation of these cells is influenced by physical and molecular interactions with stromal cells and extracellular matrix molecules forming the specialized microenvironment of dental pulp stem cell niches. Here we study the activation of putative pulp niches after tooth injury through the upregulation of Notch signaling pathway. Notch1, Notch2, and Notch3 molecules were used as markers of dental pulp stem/progenitor cells. Upon dental injury, Notch1 and Notch3 are detected in cells related to vascular structures suggesting a role of these proteins in the activation of specific pulpal perivascular niches. In contrast, a population of Notch2-positive cells that are actively proliferative is observed in the apical part of the pulp. Kinetics of these cells is followed up with a lipophilic DiI labeling, showing that apical pulp cells migrate toward the injury site where dynamic regenerative/repair events occur. The knowledge of the activation and regulation of dental pulp stem/progenitor cells within their niches in pathologic conditions may be helpful for the realization of innovative dental treatments in the near future. PMID:28611689

Idiopathic dental pulp calcifications in a tertiary care setting in South India

PubMed Central

Satheeshkumar, PS; Mohan, Minu P; Saji, Sweta; Sadanandan, Sudheesh; George, Giju

2013-01-01

Background: Dental pulp calcifications are unique and represent the dental pulp regenerative process. Dental pulp calcifications are sometimes routine findings in oral radiographs and may later serve as an important diagnostic criterion for a hidden aspect of systemic illness. Objective: The purpose of this study was to assess the patterns and prevalence of idiopathic dental pulp calcifications in a tertiary care setting in South India. Materials and Methods: A total of 227 patients were included in the study fulfilling the inclusion criteria. Age range of the study population was from 15 to 70 years. Teeth were examined under digital panoramic radiograph. The presence or absence of pulp stones was recorded. The presence of pulp stone were categorized according to the types classified as Type I, Type IA, Type II, Type IIA, Type II B, and Type III. The frequency of occurrence of pulp stones with sex, tooth type, dental arches, and types were compared with the types of calcification. Results: Total no. of patients with pulpal calcification were 227 [females 133 (58.59%) and males 94 (41.40%)]. The most common type between both sexes was Type I (48%). Total no. of teeth with calcification was 697; maxilla (48%), mandible (52%). The prevalence of pulp stone was found to be higher in the molars in both the arches. Most no. of pulp stones are reported at the third and fourth decade of life. Conclusion: Idiopathic dental pulp calcifications are incidental radiographic findings of the pulp tissue and also may be an indicator of underlying disease. PMID:23349577

Microarray evaluation of gene expression profiles in inflamed and healthy human dental pulp: the role of IL1beta and CD40 in pulp inflammation.

PubMed

Gatta, V; Zizzari, V L; Dd ' Amico, V; Salini, L; D' Aurora, M; Franchi, S; Antonucci, I; Sberna, M T; Gherlone, E; Stuppia, L; Tetè, S

2012-01-01

Dental pulp undergoes a number of changes passing from healthy status to inflammation due to deep decay. These changes are regulated by several genes resulting differently expressed in inflamed and healthy dental pulp, and the knowledge of the processes underlying this differential expression is of great relevance in the identification of the pathogenesis of the disease. In this study, the gene expression profile of inflamed and healthy dental pulps were compared by microarray analysis, and data obtained were analyzed by Ingenuity Pathway Analysis (IPA) software. This analysis allows to focus on a variety of genes, typically expressed in inflamed tissues. The comparison analysis showed an increased expression of several genes in inflamed pulp, among which IL1β and CD40 resulted of particular interest. These results indicate that gene expression profile of human dental pulp in different physiological and pathological conditions may become an useful tool for improving our knowledge about processes regulating pulp inflammation.

Osteoblastic differentiating potential of dental pulp stem cells in vitro cultured on a chemically modified microrough titanium surface.

PubMed

DE Colli, Marianna; Radunovic, Milena; Zizzari, Vincenzo L; DI Giacomo, Viviana; DI Nisio, Chiara; Piattelli, Adriano; Calvo Guirado, José L; Zavan, Barbara; Cataldi, Amelia; Zara, Susi

2018-03-30

Titanium surface modification is critical for dental implant success. Our aim was to determine surfaces influence on dental pulp stem cells (DPSCs) viability and differentiation. Implants were divided into sandblasted/acid-etched (control) and sandblasted/acid-etched coated with calcium and magnesium ions (CaMg), supplied as composite (test). Proliferation was evaluated by MTT, differentiation checking osteoblastic gene expression, PGE2 secretion and matrix formation, inflammation by Interleukin 6 (IL-6) detection. MTT and IL-6 do not modify on test. A PGE2 increase on test is recorded. BMP2 is higher on test at early experimental points, Osterix and RUNX2 augment later. Alizarin-red S reveals higher matrix production on test. These results suggest that test surface is more osteoinductive, representing a start point for in vivo studies aiming at the construction of more biocompatible dental implants, whose integration and clinical performance are improved and some undesired effects, such as implant stability loss and further surgical procedures, are reduced.

21 CFR 872.1720 - Pulp tester.

Code of Federal Regulations, 2011 CFR

2011-04-01

... DENTAL DEVICES Diagnostic Devices § 872.1720 Pulp tester. (a) Identification. A pulp tester is an AC or... current transmitted by an electrode to stimulate the nerve tissue in the dental pulp. (b) Classification...

21 CFR 872.1720 - Pulp tester.

Code of Federal Regulations, 2014 CFR

2014-04-01

... DENTAL DEVICES Diagnostic Devices § 872.1720 Pulp tester. (a) Identification. A pulp tester is an AC or... current transmitted by an electrode to stimulate the nerve tissue in the dental pulp. (b) Classification...

An in vivo model for evaluating the response of pulp to various biomaterials.

PubMed

McClugage, S G; Holmstedt, J O; Malloy, R B

1980-09-01

An in vivo model has been designed to study the acute response of exposed or unexposed dental pulp to the topical application of various biomaterials. This model permits sequential microscopic observations of the microvascular system of dental pulp before and after application of pulp capping agents, cementing agents, or cavity liners. The use of this experimental model provides useful information related to the tolerability of dental pulp to various biomaterials used in dentistry. Furthermore, this model serves as a useful supplement to more traditional long term methods for evaluating the biocompatability of dental materials.

Prevalence of Coronal Pulp Stones and Its Relation with Systemic Disorders in Northern Indian Central Punjabi Population

PubMed Central

Bains, Sandeep Kumar; Bhatia, Archana; Singh, Harkanwal Preet; Biswal, Swati Swagatika; Kanth, Shashi; Nalla, Srinivas

2014-01-01

Aim. To estimate the prevalence of coronal pulp stones in the molar teeth of dental outpatients of Sunam, Sangrur district, Punjab, India, to report any association between occurrence of pulp stones with age, gender, dental arch, side, and dental status and to find out correlation between pulp stones with dental and systemic diseases. Materials and Methods. 500 routine dental outpatients within age group of 18–67 years were involved in the study. Molar bitewing of left and right side of each patient was taken with XCP bitewing instrument and size 2 film. The presence or absence of pulp stones was recorded. Chi-square analysis was used to record the prevalence of pulp stones and to compare it with demographic and systemic factors. Results. Overall prevalence of pulp stones was 41.8%. Pulp stones were significantly higher in maxilla (11.59%) than mandible (6.54%), left side than right side, and first molar than other molars. Higher numbers of pulp stones were recorded in patients with cardiovascular disease (38.89%) than with cholelithiasis and renal lithiasis. Conclusion. Pulp stones were higher in maxillary arch than mandibular arch and in females than males. Cardiovascular patients had higher number of pulp stones than other groups. PMID:24944821

Tissue engineering: Dentin - pulp complex regeneration approaches (A review).

PubMed

Hashemi-Beni, Batool; Khoroushi, Maryam; Foroughi, Mohammad Reza; Karbasi, Saeed; Khademi, Abbas Ali

2017-10-01

Dental pulp is a highly specialized tissue that preserves teeth. It is important to maintain the capabilities of dental pulp before a pulpectomy by creating a local restoration of the dentin-pulp complex from residual dental pulp. The articles identified were selected by two reviewers based on entry and exit criteria. All relevant articles indexed in PubMed, Springer, Science Direct, and Scopus with no limitations from 1961 to 2016 were searched. Factors investigated in the selected articles included the following key words: Dentin-Pulp Complex, Regeneration, Tissue Engineering, Scaffold, Stem Cell, and Growth Factors. Of the 233 abstracts retrieved, the papers which were selected had evaluated the clinical aspects of the application of dentin-pulp regeneration. Generally, this study has introduced a new approach to provoke the regeneration of the dentin-pulp complex after a pulpectomy, so that exogenous growth factors and the scaffold are able to induce cells and blood vessels from the residual dental pulp in the tooth root canal. This study further presents a new strategy for local regeneration therapy of the dentin-pulp complex. This review summarizes the current knowledge of the potential beneficial effects derived from the interaction of dental materials with the dentin-pulp complex as well as potential future developments in this exciting field. Copyright © 2017 Elsevier Ltd. All rights reserved.

Uremia Induces Dental Pulp Ossification but Reciprocally Inhibits Adjacent Alveolar Bone Osteogenesis.

PubMed

Yang, Chih-Yu; Chang, Zee-Fen; Chau, Yat-Pang; Chen, Ann; Lee, Oscar Kuang-Sheng; Yang, An-Hang

2015-11-01

Uremic patients are predisposed to atrophy of the alveolar bone and narrowing of the dental pulp chamber. Such pulp chamber changes have only been diagnosed radiologically; however, this has not been supported by any pathological evidence. We used a uremic rat model with secondary hyperparathyroidism induced by 5/6 nephrectomy surgery and high-phosphate diet to examine the dental pulp and adjacent alveolar bone pathology. In addition, we collected pulp tissues for real-time PCR. We found an opposite histopathological presentation of the ossified dental pulp and the osteomalacic adjacent alveolar bone. Furthermore, pulp cells with positive staining for Thy-1, a surrogate stem cell marker, were significantly reduced in the pulp of uremic rats compared to the controls, indicating a paucity of stem cells. This was further evidenced by the reduced pulp expression of dickkopf-1 (Dkk-1), a Wnt/β-catenin signaling inhibitor produced by mesenchymal stem cells. In contrast, expressions of receptor activator of nuclear factor κB ligand (RANKL) and RANK in uremic pulp were up-regulated, probably to counteract the ossifying process of uremic pulp. In conclusion, uremic pulp ossifications were associated with a paucity of stem cells and dysregulated Dkk-1 and RANKL signaling systems, further shifting the imbalance toward osteogenesis. Strategies to counteract such an imbalance may offer a potential therapeutic target to improve dental health in uremic patients, which warrants further interventional studies.

Amnesia for electric dental pulp stimulation and picture recall test under different levels of propofol or midazolam sedation.

PubMed

Matsuki, Y; Ichinohe, T; Kaneko, Y

2007-01-01

To compare the amnesic effect of propofol and midazolam to electric dental pulp stimulation (invasive) and picture recall test (non-invasive) at two sedation levels with the aid of bispectral index (BIS) monitoring. The subjects were 10 male volunteers (24-34 years) classified as ASA physical status I. Propofol was administered to achieve a sedation score of three with a target-controlled infusion technique; it was then regulated to give a sedation score of two (P group). Midazolam was administered by a titration dosage to achieve a sedation score of three (M group). It then gradually decreased to give a sedation score of two. The BIS score, sedation score, plasma/serum concentration of propofol and midazolam, blood pressure, pulse rate, respiratory rate, end-tidal CO(2) tension and arterial oxygen saturation were observed at each sedation level in both groups. Amnesic effects were evaluated using a picture recall test and electric dental pulp stimulation. No difference was observed in the amnesic effect evaluated by picture recall test at the two sedation levels. Likewise, there was no difference at a sedation score of three when the amnesic effect was evaluated by electric dental pulp stimulation. In contrast, a significant difference was observed at a sedation score of two; midazolam produced amnesia in more subjects than did propofol. Propofol and midazolam did not show any significant difference in amnesic effects to non-invasive stimuli. For invasive stimuli, midazolam showed a stronger amnesic effect at the moderate sedation level, but not at the deeper sedation level.

Paleoproteomics of the Dental Pulp: The plague paradigm.

PubMed

Barbieri, Rémi; Mekni, Rania; Levasseur, Anthony; Chabrière, Eric; Signoli, Michel; Tzortzis, Stéfan; Aboudharam, Gérard; Drancourt, Michel

2017-01-01

Chemical decomposition and fragmentation may limit the detection of ancient host and microbial DNA while some proteins can be detected for extended periods of time. We applied paleoproteomics on 300-year-old dental pulp specimens recovered from 16 individuals in two archeological funeral sites in France, comprising one documented plague site and one documented plague-negative site. The dental pulp paleoproteome of the 16 teeth comprised 439 peptides representative of 30 proteins of human origin and 211 peptides representative of 27 proteins of non-human origin. Human proteins consisted of conjunctive tissue and blood proteins including IgA immunoglobulins. Four peptides were indicative of three presumable Yersinia pestis proteins detected in 3/8 dental pulp specimens from the plague-positive site but not in the eight dental pulp specimens collected in the plague-negative site. Paleoproteomics applied to the dental pulp is a new and innovative approach to screen ancient individuals for the detection of blood-borne pathogens and host inflammatory response.

Histopathologic changes in dental pulp of teeth with chronic periodontitis.

PubMed

Aguiar, Telma R; Tristao, Gilson C; Mandarino, Denize; Zarranz, Laila; Ferreira, Vinicius F; Barboza, Eliane P

2014-05-01

The aim of this study was to evaluate the histopathologic changes in dental pulp of teeth with chronic advanced periodontitis. In 22 patients, 30 teeth were selected for inclusion. Patients had received no periodontal treatment. No teeth had caries, abrasion, attrition, erosion, trauma, or restoration. Radiographically, all teeth showed bone-support destruction to the apex. Thermal and cavity tests were used to evaluate pulp vitality. After tooth extractions, crowns were separated from roots at the cementoenamel junction. Both the crowns and the roots were prepared for histopathologic analyses. Radicular pulp was analyzed considering both coronal and apical halves. In 100 percent of the cases, coronal pulp exhibited soft connective tissue. In the coronal half of radicular pulp, soft connective tissue was present in 60 percent of the cases, fibrosis in 30 percent, and fibrosis associated with dystrophic calcification in 10 percent. In the apical half of radicular pulp, 6.6 percent of the cases demonstrated fibrosis; 23 percent exhibited fibrosis associated with pulp atrophy and secondary dentin; and 63.3 percent showed fibrosis, pulp atrophy, secondary dentin, and diffuse calcification. Radicular pulp of teeth with chronic periodontitis presents characteristics compatible with pulp changes resulting from pulp aging. In such cases, endodontic treatment is not indicated to enhance periodontal treatment results.

Orthodontic treatment mediates dental pulp microenvironment via IL17A.

PubMed

Yu, Wenjing; Zhang, Yueling; Jiang, Chunmiao; He, Wei; Yi, Yating; Wang, Jun

2016-06-01

Orthodontic treatment induces dental tissue remodeling; however, dental pulp stem cell (DPSC)-mediated pulp micro-environmental alteration is still largely uncharacterized. In the present study, we identified elevated interleukin-17A (IL17A) in the dental pulp, which induced the osteogenesis of DPSCs after orthodontic force loading. Tooth movement animal models were established in Sprague-Dawley rats, and samples were harvested at 1, 4, 7, 14, and 21 days after orthodontic treatment loading. DPSC self-renewal and differentiation at different time points were examined, as well as the alteration of the microenvironment of dental pulp tissue by histological analysis and the systemic serum IL17A expression level by an ELISA assay. In vitro recombinant IL17A treatment was used to confirm the effect of IL17A on the enhancement of DPSC self-renewal and differentiation. Orthodontic treatment altered the dental pulp microenvironment by activation of the pro-inflammatory cytokine IL17A in vivo. Orthodontic loading significantly promoted the self-renewal and differentiation of DPSCs. Inflammation and elevated IL17A secretion occurred in the dental pulp during orthodontic tooth movement. Moreover, in vitro recombinant IL17A treatment mimicked the enhancement of the self-renewal and differentiation of DPSCs. Orthodontic treatment enhanced the differentiation and self-renewal of DPSCs, mediated by orthodontic-induced inflammation and subsequent elevation of IL17A level in the dental pulp microenvironment. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Vital pulp therapy of damaged dental pulp].

PubMed

Xuedong, Zhou; Dingming, Huang; Jianguo, Liu; Zhengwei, Huang; Xin, Wei; Deqin, Yang; Jin, Zhao; Liming, Chen; Lin, Zhu; Yanhong, Li; Jiyao, Li

2017-08-01

The development of an expert consensus on vital pulp therapy can provide practical guidance for the improvement of pulp damage care in China. Dental pulp disease is a major type of illness that adversely affects human oral health. Pulp capping and pulpotomy are currently the main methods for vital pulp therapy. Along with the development of minimal invasion cosmetic dentistry, using different treatment technologies and materials reasonably, preserving healthy tooth tissue, and extending tooth save time have become urgent problems that call for immediate solution in dental clinics. This paper summarizes the experiences and knowledge of endodontic experts. We develop a clinical path of vital pulp therapy for clinical work by utilizing the nature, approach, and degree of pulp damage as references, defense and self-repairing ability of pulp as guidance, and modern technologies of diagnosis and treatment as means.

Histological transformations of the dental pulp as possible indicator of post mortem interval: a pilot study.

PubMed

Carrasco, Patricio A; Brizuela, Claudia I; Rodriguez, Ismael A; Muñoz, Samuel; Godoy, Marianela E; Inostroza, Carolina

2017-10-01

The correct estimation of the post mortem interval (PMI) can be crucial on the success of a forensic investigation. Diverse methods have been used to estimate PMI, considering physical changes that occur after death, such as mortis algor, livor mortis, among others. Degradation after death of dental pulp is a complex process that has not yet been studied thoroughly. It has been described that pulp RNA degradation could be an indicator of PMI, however this study is limited to 6 days. The tooth is the hardest organ of the human body, and within is confined dental pulp. The pulp morphology is defined as a lax conjunctive tissue with great sensory innervation, abundant microcirculation and great presence of groups of cell types. The aim of this study is to describe the potential use of pulp post mortem alterations to estimate PMI, using a new methodology that will allow obtainment of pulp tissue to be used for histomorphological analysis. The current study will identify potential histological indicators in dental pulp tissue to estimate PMI in time intervals of 24h, 1 month, 3 months and 6 months. This study used 26 teeth from individuals with known PMI of 24h, 1 month, 3 months or 6 months. All samples were manipulated with the new methodology (Carrasco, P. and Inostroza C. inventors; Universidad de los Andes, assignee. Forensic identification, post mortem interval estimation and cause of death determination by recovery of dental tissue. United State patent US 61/826,558 23.05.2013) to extract pulp tissue without the destruction of the tooth. The dental pulp tissues obtained were fixed in formalin for the subsequent generation of histological sections, stained with Hematoxylin Eosin and Masson's Trichrome. All sections were observed under an optical microscope using magnifications of 10× and 40×. The microscopic analysis of the samples showed a progressive transformation of the cellular components and fibers of dental pulp along PMI. These results allowed creating a chart of qualitative and quantitative parameters to be used on the estimation on PMI based on microscopic degradation of dental pulp. The histological transformations of dental pulp as a function of time can be used as PMI indicators. Copyright © 2017 Elsevier B.V. All rights reserved.

DENTAL PULP TISSUE ENGINEERING

PubMed Central

Demarco, FF; Conde, MCM; Cavalcanti, B; Casagrande, L; Sakai, V; Nör, JE

2013-01-01

Dental pulp is a highly specialized mesenchymal tissue, which have a restrict regeneration capacity due to anatomical arrangement and post-mitotic nature of odontoblastic cells. Entire pulp amputation followed by pulp-space disinfection and filling with an artificial material cause loss of a significant amount of dentin leaving as life-lasting sequelae a non-vital and weakened tooth. However, regenerative endodontics is an emerging field of modern tissue engineering that demonstrated promising results using stem cells associated with scaffolds and responsive molecules. Thereby, this article will review the most recent endeavors to regenerate pulp tissue based on tissue engineering principles and providing insightful information to readers about the different aspects enrolled in tissue engineering. Here, we speculate that the search for the ideal combination of cells, scaffolds, and morphogenic factors for dental pulp tissue engineering may be extended over future years and result in significant advances in other areas of dental and craniofacial research. The finds collected in our review showed that we are now at a stage in which engineering a complex tissue, such as the dental pulp, is no longer an unachievable and the next decade will certainly be an exciting time for dental and craniofacial research. PMID:21519641

Dental Pulp Defence and Repair Mechanisms in Dental Caries

PubMed Central

Farges, Jean-Christophe; Alliot-Licht, Brigitte; Renard, Emmanuelle; Ducret, Maxime; Gaudin, Alexis; Smith, Anthony J.; Cooper, Paul R.

2015-01-01

Dental caries is a chronic infectious disease resulting from the penetration of oral bacteria into the enamel and dentin. Microorganisms subsequently trigger inflammatory responses in the dental pulp. These events can lead to pulp healing if the infection is not too severe following the removal of diseased enamel and dentin tissues and clinical restoration of the tooth. However, chronic inflammation often persists in the pulp despite treatment, inducing permanent loss of normal tissue and reducing innate repair capacities. For complete tooth healing the formation of a reactionary/reparative dentin barrier to distance and protect the pulp from infectious agents and restorative materials is required. Clinical and in vitro experimental data clearly indicate that dentin barrier formation only occurs when pulp inflammation and infection are minimised, thus enabling reestablishment of tissue homeostasis and health. Therefore, promoting the resolution of pulp inflammation may provide a valuable therapeutic opportunity to ensure the sustainability of dental treatments. This paper focusses on key cellular and molecular mechanisms involved in pulp responses to bacteria and in the pulpal transition between caries-induced inflammation and dentinogenic-based repair. We report, using selected examples, different strategies potentially used by odontoblasts and specialized immune cells to combat dentin-invading bacteria in vivo. PMID:26538821

Dental Pulp Defence and Repair Mechanisms in Dental Caries.

PubMed

Farges, Jean-Christophe; Alliot-Licht, Brigitte; Renard, Emmanuelle; Ducret, Maxime; Gaudin, Alexis; Smith, Anthony J; Cooper, Paul R

2015-01-01

Dental caries is a chronic infectious disease resulting from the penetration of oral bacteria into the enamel and dentin. Microorganisms subsequently trigger inflammatory responses in the dental pulp. These events can lead to pulp healing if the infection is not too severe following the removal of diseased enamel and dentin tissues and clinical restoration of the tooth. However, chronic inflammation often persists in the pulp despite treatment, inducing permanent loss of normal tissue and reducing innate repair capacities. For complete tooth healing the formation of a reactionary/reparative dentin barrier to distance and protect the pulp from infectious agents and restorative materials is required. Clinical and in vitro experimental data clearly indicate that dentin barrier formation only occurs when pulp inflammation and infection are minimised, thus enabling reestablishment of tissue homeostasis and health. Therefore, promoting the resolution of pulp inflammation may provide a valuable therapeutic opportunity to ensure the sustainability of dental treatments. This paper focusses on key cellular and molecular mechanisms involved in pulp responses to bacteria and in the pulpal transition between caries-induced inflammation and dentinogenic-based repair. We report, using selected examples, different strategies potentially used by odontoblasts and specialized immune cells to combat dentin-invading bacteria in vivo.

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

PubMed Central

SIPERT, Carla Renata; MORANDINI, Ana Carolina de Faria; MODENA, Karin Cristina da Silva; DIONÍSIO, Thiago José; MACHADO, Maria Aparecida Andrade Moreira; de OLIVEIRA, Sandra Helena Penha; CAMPANELLI, Ana Paula; SANTOS, Carlos Ferreira

2013-01-01

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 µg/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. PMID:23739851

Synthetic octacalcium phosphate-enhanced reparative dentine formation via induction of odontoblast differentiation.

PubMed

Wang, Xiaogu; Suzawa, Tetsuo; Miyauchi, Tomohiko; Zhao, Baohong; Yasuhara, Rika; Anada, Takahisa; Nakamura, Masanori; Suzuki, Osamu; Kamijo, Ryutaro

2015-11-01

Synthetic octacalcium phosphate (OCP) has been suggested to be a useful biomaterial for the regeneration of hard tissues, including bone. However, it remains unknown whether OCP induces dentine formation by dental pulp. We investigated biomineralization of dental pulp exposed to synthetic OCP in vitro and in vivo. When dental pulp was exposed directly to OCP, rapid formation of reparative dentine (RD) was induced and expression of dentine sialoprotein synthesis was observed in dental pulp adjacent to newly synthesized RD. OCP inhibited the proliferation of rat pulp cells and also promoted their odontoblastic differentiation in vitro, as alkaline phosphatase activity, mineralization of pulp cells and the expression level of dentine sialophosphoprotein were enhanced. Direct contact between OCP and pulp cells is required for OCP to exhibit its effects in vitro. The expression level of Runx2, a transcription factor whose downregulation is closely related to odontoblast differentiation, was downregulated in pulp cells cultured with OCP. Structural changes of OCP during culture were determined by Fourier transform infrared spectroscopy. OCP tended to be converted to carbonate hydroxyapatite after incubation with or without pulp cells, which may be analogous to biological apatite crystals. Taken together, our data suggest that synthetic OCP supports RD formation by dental pulp and downregulation of Runx2 may be involved in that stimulatory activity. Furthermore, OCP-apatite conversion is involved in this stimulatory capacity of OCP. Copyright © 2013 John Wiley & Sons, Ltd.

Comparative evaluation of the isolation and quantification of stem cells derived from dental pulp and periodontal ligament of a permanent tooth and to assess their viability and proliferation on a platelet-rich fibrin scaffold.

PubMed

Khurana, Rohit; Kudva, Praveen Bhasker; Husain, Syed Yawer

2017-01-01

The present study aims to comparatively evaluate the isolation and quantification of stem cells derived from dental pulp and periodontal ligament of a permanent tooth and to assess their viability and proliferation on a platelet-rich fibrin (PRF) scaffold. A total of 15 systemically healthy individuals between the age group of 15-25 years requiring third molar or orthodontic premolar extractions. Teeth were extracted atraumatically and transported to the laboratory. Stem cells were isolated from dental pulp and periodontal ligament. After attaining more than 90% confluency by the 7 th day, these cells were tested for their viability and characterization. Stem cells were also incubated with PRF and viability was assessed on the 7 th day. The mean number of cell for dental pulp stem cells (DPSCs) and periodontal ligament stem cell (PDLSC) was statistically insignificant ( P > 0.05). The mean live cell viability was compared between DPSC (98.07%) and PDLSC (98%). Both DPSC and PDLSC showed a high percentage of expression of CD73 markers, 30.40% and 29.80%, respectively. However, DPSCs and PDLSCs lacked expression of CD34 expressing only 3.47% and 3.53%, respectively. PRF membrane as a scaffold exhibited no cytotoxic effects on DPCS's or PDLSC's. The cell viability of cells cultured with PRF was statistically insignificant ( P > 0.05) when compared to the cells cultured with culture media. The study thus indicates that dental pulp and periodontal ligament are both rich sources of mesenchymal stem cells and can be successfully used for obtaining stem cells. PRF exhibits no cytotoxic effects on the cells and can be used in conjunction with dental stem cells.

[Biochemical study of the dental pulp in the calf].

PubMed

Vernole, B; Caprioglio, D; Mincione, E; Vannini, V; Tomasi, A; Bini, A; Franceschini, V

1990-01-01

A biochemical study of dental pulp of calves has been performed concerning: a) peroxydability b) A, E, C vitamins content c) glutation (GSH) content d) presence of paramagnetic compounds e) phosphorylation ratio The dental pulp from incisors of 5-months-old calves has been preserved. Immediately after decapitation the pulp was immersed in liquid nitrogen. Chromatographic (HPLC) and spectroscopic (NMR-ESR) techniques have been used. GSH in dental pulp are present and dosable (4.56 +/- 0.08 n moles/mg prot.) and GSSG (1.05 +/- 0.01 n moles/mg prot.). Because of blood traces in the extracted pulps, the AA. have determined the hemoglobin (Hb) dosage and GSH of erythrocytic derivation (Fig. 1). After deduction of GSH of erythrocytic derivation, the GSH really present in the pulp was 4.41 n moles/mg prot. and the GSSG was 0.90 n moles/mg prot. Peroxydability of the dental pulp has been evaluated with Lowry method with dental pulp homogenate and rat liver homogenate (see Table 1). The ESR spectre shows 4 resonances with the following values: g. 2.24-2.04-2.00-1.97; there are some free intermediary radicals (gr.-2.00) (Fig.2). The NMR spectre shows the presence of ATP (0.22 n moles/g) of inorganic phosphate (16.58 n moles g) (Fig.3). The pulp seems to have a lot of antioxidant factors. The next researches will be to study E, A and C vitamins concentrations. This high presence of GSH and GSSG may be an embryonic peculiarity.

Determining predictability and accuracy of thermal and electrical dental pulp tests: An in vivo study.

PubMed

Salgar, Avinash Ramchandra; Singh, Shishir H; Podar, Rajesh S; Kulkarni, Gaurav P; Babel, Shashank N

2017-01-01

Pulp sensitivity testing, even with its limitations and shortcomings, has been and still remains a very helpful aid in endodontic diagnosis. Pulp sensitivity tests extrapolate pulpal health from the sensory response. The aim of the present study was to identify the sensitivity, specificity, positive and negative predictive values (NPVs) of thermal and electrical tests of pulp sensitivity. Pulp tests studied were two cold and heat tests respectively and electrical test. A total of 330 teeth were tested: 198 teeth with vital pulp and 132 teeth with necrotic pulps (disease prevalence of 40%). The ideal standard was established by observing bleeding within the pulp chamber. Sensitivity values of the diagnostic tests were 0.89 and 0.94 for cold test, 0.84 and 0.87 for the heat tests, and 0.75 for electrical pulp test and the specificity values of the diagnostic tests were 0.91 and 0.93 for the cold tests, 0.86 and 0.84 for the heat tests, and 0.90 for electrical pulp test. The NPVs were 0.91 and 0.96 for the cold tests, 0.89 and 0.91 for the heat tests, and 0.84 for electrical pulp test. The positive predictive values were 0.89 and 0.90 for the cold tests, 0.80 and 0.79 for the heat tests and 0.88 for electrical pulp test. The highest accuracy (0.9393) was observed with cold test (icy spray). The cold test done with icy spray was the most accurate method for sensitivity testing.

EDTA conditioning of dentine promotes adhesion, migration and differentiation of dental pulp stem cells.

PubMed

Galler, K M; Widbiller, M; Buchalla, W; Eidt, A; Hiller, K-A; Hoffer, P C; Schmalz, G

2016-06-01

To evaluate the effect of dentine conditioning on migration, adhesion and differentiation of dental pulp stem cells. Dentine discs prepared from extracted human molars were pre-treated with EDTA (10%), NaOCl (5.25%) or H2 O. Migration of dental pulp stem cells towards pre-treated dentine after 24 and 48 h was assessed in a modified Boyden chamber assay. Cell adhesion was evaluated indirectly by measuring cell viability. Expression of mineralization-associated genes (COL1A1, ALP, BSP, DSPP, RUNX2) in cells cultured on pre-treated dentine for 7 days was determined by RT-qPCR. Nonparametric statistical analysis was performed for cell migration and cell viability data to compare different groups and time-points (Mann-Whitney U-test, α = 0.05). Treatment of dentine with H2 O or EDTA allowed for cell attachment, which was prohibited by NaOCl with statistical significance (P = 0.000). Furthermore, EDTA conditioning induced cell migration towards dentine. The expression of mineralization-associated genes was increased in dental pulp cells cultured on dentine after EDTA conditioning compared to H2 O-pre-treated dentine discs. EDTA conditioning of dentine promoted the adhesion, migration and differentiation of dental pulp stem cells towards or onto dentine. A pre-treatment with EDTA as the final step of an irrigation protocol for regenerative endodontic procedures has the potential to act favourably on new tissue formation within the root canal. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

A comparison of knowledge of local analgesia, pulp therapy and restoration of primary molar teeth amongst dental students, dentists and dental therapists within a dental hospital setting.

PubMed

Foley, J

2007-06-01

To gain an overview of knowledge of local analgesia, pulpal therapy and restorative procedures in the primary dentition amongst dental undergraduate students (DS), dental therapy students (DTS), recently-qualified dentists (QD) and dental therapists (DT), working within a Dental Hospital setting. A survey undertaken at Dundee Dental Hospital and School, NHS Tayside, United Kingdom to determine current knowledge regarding the use of local analgesia, pulp anatomy and pulp therapy techniques in addition to restoration of primary teeth. Data were available for 24 individuals (DS: 5; QD: 6; DTS: 8; DT: 5). Deficiencies in knowledge regarding the maximum safe dose for local analgesia, pulp canal anatomy, pulp therapy medicaments and the preparation required prior to placement of a pre-formed metal crown were noted in both student and staff groups. The knowledge of basic dental procedures for children amongst a group of dental students, student dental therapists and recently qualified dentists and dental therapists, was found to be imperfect. These findings indicate that more research is needed on the educational procedures used in the transfer of such knowledge and skills. Deficiencies in knowledge were identified in all areas assessed. Courses should be designed at both the pre- and postgraduate level to address and avoid such gaps in knowledge.

Human dental pulp stem cells derived from cryopreserved dental pulp tissues of vital extracted teeth with disease demonstrate hepatic-like differentiation.

PubMed

Chen, Y K; Huang, Anderson H C; Chan, Anthony W S; Lin, L M

2016-06-01

Reviewing the literature, hepatic differentiation of human dental pulp stem cells (hDPSCs) from cryopreserved dental pulp tissues of vital extracted teeth with disease has not been studied. This study is aimed to evaluate the hypothesis that hDPSCs from cryopreserved dental pulp tissues of vital extracted teeth with disease could possess potential hepatic differentiation. Forty vital extracted teeth with disease recruited for hDPSCs isolation, stem cell characterization and hepatic differentiation were randomly and equally divided into group A (liquid nitrogen-stored dental pulp tissues) and group B (freshly derived dental pulp tissues). Samples of hDPSCs isolated from groups A and B but without hepatic growth factors formed negative controls. A well-differentiated hepatocellular carcinoma cell line was employed as a positive control. All the isolated hDPSCs from groups A and B showed hepatic-like differentiation with morphological change from a spindle-shaped to a polygonal shape and normal karyotype. Differentiated hDPSCs and the positive control expressed hepatic metabolic function genes and liver-specific genes. Glycogen storage of differentiated hDPSCs was noted from day 7 of differentiation-medium culture. Positive immunofluorescence staining of low-density lipoprotein and albumin was observed from day 14 of differentiation-medium culture; urea production in the medium was noted from week 6. No hepatic differentiation was observed for any of the samples of the negative controls. We not only demonstrated the feasibility of hepatic-like differentiation of hDPSCs from cryopreserved dental pulp tissues of vital extracted teeth with disease but also indicated that the differentiated cells possessed normal karyotype and were functionally close to normal hepatic-like cells. Copyright © 2013 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Fibroblast growth factor-2 regulates the cell function of human dental pulp cells.

PubMed

Shimabukuro, Yoshio; Ueda, Maki; Ozasa, Masao; Anzai, Jun; Takedachi, Masahide; Yanagita, Manabu; Ito, Masako; Hashikawa, Tomoko; Yamada, Satoru; Murakami, Shinya

2009-11-01

Homeostasis and tissue repair of dentin-pulp complex are attributed to dental pulp tissue and several growth factors. Dental pulp cells play a pivotal role in homeostasis of dentin-pulp complex and tissue responses after tooth injury. Among these cytokines, fibroblast growth factor (FGF)-2 has multifunctional biologic activity and is known as a signaling molecule that induces tissue regeneration. In this study, we examined the effects of FGF-2 on growth, migration, and differentiation of human dental pulp cells (HDPC). HDPC were isolated from healthy dental pulp. Cellular response was investigated by [(3)H]-thymidine incorporation into DNA. Cytodifferentiation was examined by alkaline phosphatase (ALPase) assay and cytochemical staining of calcium by using alizarin red. Migratory activity was determined by counting the cells migrating into cleared area that had introduced with silicon block. FGF-2 activated HDPC growth and migration but suppressed ALPase activity and calcified nodule formation. Interestingly, HDPC, which had been pretreated with FGF-2, showed increased ALPase activity and calcified nodule formation when subsequently cultured without FGF-2. These results suggest that FGF-2 potentiates cell growth and accumulation of HDPC that notably did not disturb cytodifferentiation of the cells later. Thus, FGF-2 is a favorable candidate for pulp capping agent. These results provide new evidence for the possible involvement of FGF-2 not only in homeostasis but also in regeneration of dentin-pulp complex.

In vitro proliferation and osteogenic differentiation of human dental pulp stem cells in injectable thermo-sensitive chitosan/β-glycerophosphate/hydroxyapatite hydrogel.

PubMed

Chen, Yantian; Zhang, Fengli; Fu, Qiang; Liu, Yong; Wang, Zejian; Qi, Nianmin

2016-09-01

Injectable thermo-sensitive hydrogels have a potential application in bone tissue engineering for their sensitivities and minimal invasive properties. Human dental pulp stem cells have been considered a promising tool for tissue reconstruction. The objective of this study was to investigate the proliferation and osteogenic differentiation of dental pulp stem cells in injectable thermo-sensitive chitosan/β-glycerophosphate/hydroxyapatite hydrogel in vitro. The chitosan /β-glycerophosphate hydrogel and chitosan/β-glycerophosphate/hydroxyapatite hydrogel were prepared using the sol-gel method. The injectability of chitosan /β-glycerophosphate hydrogel and chitosan/β-glycerophosphate/hydroxyapatite hydrogel was measured using a commercial disposable syringe. Scanning electron microscopy was used to observe the inner structure of hydrogels. Then dental pulp stem cells were seeded in chitosan /β-glycerophosphate hydrogel and chitosan/β-glycerophosphate/hydroxyapatite hydrogel, respectively. The growth of dental pulp stem cells was periodically observed under an inverted microscope. The proliferation of dental pulp stem cells was detected by using an Alamar Blue kit, while cell apoptosis was determined by using a Live/Dead Viability/Cytotoxicity kit. The osteogenic differentiations of dental pulp stem cells in chitosan /β-glycerophosphate hydrogel and chitosan/β-glycerophosphate/hydroxyapatite hydrogel were evaluated by alkaline phosphatase activity assay and mRNA expression of osteogenesis gene for 21 days in osteogenic medium. The results indicated that there was no significant difference between chitosan /β-glycerophosphate hydrogel and chitosan/β-glycerophosphate/hydroxyapatite hydrogel in injectability. Cells within the chitosan/β-glycerophosphate/hydroxyapatite hydrogel displayed a typical adherent cell morphology and rapid proliferation with high cellular viability after 14 days of culture. Dental pulp stem cells seeded in chitosan/β-glycerophosphate/hydroxyapatite hydrogels had a higher alkaline phosphatase activity and better up-regulation of gene expression levels of Runx-2, Collagen I, alkaline phosphatase and osteocalcin than in chitosan /β-glycerophosphate hydrogels after osteogenic differentiation. These results demonstrated that the chitosan/β-glycerophosphate/hydroxyapatite hydrogel had excellent cellular compatibility and the superiority in promoting dental pulp stem cells osteogenic differentiation in vitro, showing that the combination of dental pulp stem cells and chitosan/β-glycerophosphate/hydroxyapatite hydrogel has the potential to be used for bone tissue engineering. © The Author(s) 2016.

Inflammatory response of human dental pulp to at-home and in-office tooth bleaching

PubMed Central

Vaz, Maysa Magalhães; Lopes, Lawrence Gonzaga; Cardoso, Paula Carvalho; de Souza, João Batista; Batista, Aline Carvalho; Costa, Nádia Lago; Torres, Érica Miranda; Estrela, Carlos

2016-01-01

ABSTRACT Tooth bleaching is a technique of choice to obtain a harmonious smile, but bleaching agents may damage the dental pulp. Objective: This study evaluated the inflammatory responses of human dental pulp after the use of two bleaching techniques. Material and Methods: Pulp samples were collected from human third molars extracted for orthodontic reasons and divided into three groups: control - no tooth bleaching (CG) (n=7); at-home bleaching with 15% carbamide peroxide (AH) (n = 10), and in-office bleaching with 38% hydrogen peroxide (IO) (n=12). Pulps were removed and stained with hematoxylin-eosin for microscopic analysis of inflammation intensity, collagen degradation, and pulp tissue organization. Immunohistochemistry was used to detect mast cells (tryptase+), blood vessels (CD31+), and macrophages (CD68+). Chi-square, Kruskal-Wallis, and Mann Whitney tests were used for statistical analysis. The level of significance was set at p<.05. Results: The inflammation intensity and the number of macrophages were significantly greater in IO than in AH and CG (p<0.05). The results of CD31+ (blood vessels per mm2) were similar in CG (61.39±20.03), AH (52.29±27.62), and IO (57.43±8.69) groups (p>0.05). No mast cells were found in the pulp samples analyzed. Conclusion: In-office bleaching with 38% hydrogen peroxide resulted in more intense inflammation, higher macrophages migration, and greater pulp damage then at-home bleaching with 15% carbamide peroxide, however, these bleaching techniques did not induce migration of mast cells and increased the number of blood vessels. PMID:27812622

Healthy Dental Pulp Oxygen Saturation Rates in Subjects with Homozygous Sickle Cell Anemia: A Cross-Sectional Study Nested in a Cohort.

PubMed

Souza, Soraia de Fátima Carvalho; Thomaz, Erika Bárbara Abreu Fonseca; Costa, Cyrene Piazera Silva

2017-12-01

To compare the percentage of arterial oxygen saturation (SpO 2 ) in healthy teeth with confirmed pulp vitality between individuals with sickle cell anemia (HbSS) and normal hemoglobin A (HbAA). This is a cross-sectional study nested within a cohort. Samples (n = 2543) comprised teeth with intact crowns and pulp vitality confirmed by thermal sensitivity tests and no history of caries, periodontal disease, or dental trauma. A total of 728 teeth of 113 individuals with HbSS and 1815 teeth of 246 individuals with HbAA were evaluated. Data analysis was performed using the χ 2 and Mann-Whitney tests and Spearman correlation analysis (α = 0.05). The study groups were comparable in terms of age, race, and sex (P > .05). Subjects with HbSS exhibited lower median SpO 2 levels in the body and upper teeth, excluding canines, than subjects with HbAA (P < .05). There were no significant differences in the evaluated parameters between the 2 groups (P > .05). Compared with individuals with HbAA, those with HbSS exhibited lower SpO 2 in maxillary teeth with confirmed pulp vitality, except in the canines. There was no correlation between SpO 2 levels of the body and dental pulp in individuals with HbSS or HbAA. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Nicotine stimulation increases proliferation and matrix metalloproteinases-2 and -28 expression in human dental pulp cells.

PubMed

Manuela, Rizzi; Mario, Migliario; Vincenzo, Rocchetti; Filippo, Renò

2015-08-15

Dental pulp is the specialized tissue responsible for maintaining tooth viability. When tooth mineralized matrix is damaged, pulp is exposed to a plethora of environmental stimuli. In particular, in smokers, pulp become exposed to very high concentrations of nicotine. The aim of this study was to investigate the effect of direct nicotine stimulation on human dental pulp cell proliferation. Moreover, as it is known that nicotine could upregulate the expression of matrix metalloproteinases (MMPs), enzymes involved in pulpal inflammation, the effects of nicotine stimulation on MMP-2 and MMP-28 gene expression have also been investigated. Human dental pulp cells were extracted from impacted third molars obtained from healthy patients undergoing routine orthodontic treatments. Such cells were treated with growing concentrations of nicotine in the presence or absence of a nicotine antagonist (hexamethonium chloride) or of a MEK signaling inhibitor (PD98059). Cell proliferation was evaluated by cell counting, while nicotine effects on MMP expression were evaluated by PCR. The data obtained indicate that nicotine is able to increase human dental pulp cell proliferation by acting through nicotinic cholinergic receptors and downstream MAPK signaling pathway. Moreover, it is also able to increase both MMP-2 and MMP-28 gene expression. In summary these results highlight that direct exposure of human dental pulp cells to nicotine results in an inflammatory response, that could have a role in pulpal inflammation onset, a pathological condition that, when ignored, could eventually spread to the surrounding alveolar bone and progress to pulp necrosis. Copyright © 2015 Elsevier Inc. All rights reserved.

C-myb Regulates Autophagy for Pulp Vitality in Glucose Oxidative Stress.

PubMed

Lee, Y H; Kim, H S; Kim, J S; Yu, M K; Cho, S D; Jeon, J G; Yi, H K

2016-04-01

Diabetes mellitus is closely related to oral-complicated diseases by oxidative stress. This study investigates whether cellular myeloblastosis (c-myb) could protect human dental pulp cells against glucose oxidative stress and regulate autophagy activity for pulp vitality. Diabetes mellitus was induced by streptozotocin in Sprague-Dawley rats, and their pulp tissue in teeth was analyzed in terms of pulp cavity and molecules by hematoxylin and eosin and immunohistochemistry staining. Human dental pulp cells were serially subcultured and treated with glucose oxidase in the presence of elevated glucose to generate glucose oxidative stress. The replication-deficient adenovirus c-myb and small interfering RNA c-myb were introduced for c-myb expression. The pulp tissue from the diabetic rats was structurally different from normal tissue in terms of narrow pulp capacity, reduced c-myb, and dentinogenesis molecules. Glucose oxidase treatment decreased c-myb and dentinogenesis molecules (bone morphogenetic protein 2 and 7, dentin matrix protein 1, and dentin sialophosphoprotein) in human dental pulp cells. However, overexpression of c-myb by adenovirus c-myb increased dentinogenesis, autophagy molecules (autophagy protein 5, microtubule-associated protein 1A/1B-light chain 3, and Beclin-1), and cell survival via p-AMPK/AKT signaling even with glucose oxidative stress. In contrast, the lack of c-myb decreased the above molecules and cell survival by downregulating p-AMPK/AKT signaling. The results indicate that diabetes leads to irreversible damage to dental pulp, which is related to downexpression of autophagy via the p-AMPK/AKT pathway by decline of c-myb. The findings of this study provide a new insight that c-myb could ameliorate autophagy activity and that it is applicable for monitoring complicated diseases of dental pulp. The involvement of c-myb in pulp pathology could serve a therapeutic target in oral-complicated diseases. © International & American Associations for Dental Research 2015.

The Experimental Study of the Performance of Nano-Thin Polyelectrolyte Shell for Dental Pulp Stem Cells Immobilization.

PubMed

Grzeczkowicz, A; Granicka, L H; Maciejewska, I; Strawski, M; Szklarczyk, M; Borkowska, M

2015-12-01

Carious is the most frequent disease of mineralized dental tissues which might result in dental pulp inflammation and mortality. In such cases an endodontic treatment is the only option to prolong tooth functioning in the oral cavity; however, in the cases of severe pulpitis, especially when complicated with periodontal tissue inflammation, the endodontic treatment might not be enough to protect against tooth loss. Thus, keeping the dental pulp viable and/or possibility of the reconstruction of a viable dental pulp complex, appears to become a critical factor for carious and/or pulp inflammation treatment. The nowadays technologies, which allow handling dental pulp stem cells (DPSC), seem to bring us closer to the usage of dental stem cells for tooth tissues reconstruction. Thus, DPSC immobilized within nano-thin polymeric shells, allowing for a diffusion of produced factors and separation from bacteria, may be considered as a cover system supporting technology of dental pulp reconstruction. The DPSC were immobilized using a layer-by-layer technique within nano-thin polymeric shells constructed and modified by nanostructure involvement to ensure the layers stability and integrity as well as separation from bacterial cells. The cytotoxity of the material used for membrane production was assessed on the model of adherent cells. The performance of DPSC nano-coating was assessed in vitro. Membrane coatings showed no cytotoxicity on the immobilized cells. The presence of coating shell was confirmed with flow cytometry, atomic force microscopy and visualized with fluorescent microscopy. The transfer of immobilized DPSC within the membrane system ensuring cells integrity, viability and protection from bacteria should be considered as an alternative method for dental tissues transportation and regeneration.

Comparison of in vivo dental pulp responses to capping with iRoot BP Plus and mineral trioxide aggregate.

PubMed

Shi, S; Bao, Z F; Liu, Y; Zhang, D D; Chen, X; Jiang, L M; Zhong, M

2016-02-01

To compare dental pulp responses to capping with iRoot BP Plus and mineral trioxide aggregate (MTA) in dogs. Pulps in 36 incisors of three 8-month-old beagle dogs were mechanically exposed and assigned to two experimental groups (iRoot BP Plus group and MTA group, n = 15 per group) and one control group (n = 6). Direct pulp capping was performed using either iRoot BP Plus or MTA. The animals were sacrificed 3 months later. Histological sections were stained with haematoxylin and eosin and categorized using a histologic scoring system. Statistical analysis was performed using the Mann-Whitney U-test, with the significance set at 0.05. The majority of specimens in both experimental groups were associated with complete calcified bridge formation and the absence of pulpal inflammation. There was no significant difference in pulp response to iRoot BP Plus or MTA after 3 months (P > 0.05). iRoot BP Plus and MTA had similar favourable results when used as pulp-capping agents. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Role of CD146 Enrichment in Purification of Stem Cells Derived from Dental Pulp Polyp.

PubMed

Tavangar, Maryam Sadat; Hosseini, Seyed-Mojtaba; Dehghani-Nazhvani, Ali; Monabati, Ahmad

2017-01-01

Hyperplastic pulpitis (pulp polyp) tissues contains cells with stem cell properties similar to that of the dental pulp stem cells (DPSCs). It has also been shown that CD146 enrichment can homogenize the cultures of DPSCs and enhance the colony forming potentials of their cultures. This study determines whether CD146 enrichment can help purifying the stem cells from heterogeneous cultures of the pulp polyp derived stem cells (PPSCs). Healthy dental pulps and pulp polyp tissues were enzymatically digested and the harvested single cells were sorted according to the presence of CD146 marker. The sorted cells were seeded directly for colony forming unit (CFU) assays of the negative and positive portions. Flowcytometric antigen panel and differentiation assays were used to see if these cells conform with mesenchymal stems cells (MSCs) definition. Differences between the between groups was assessed using independent t-test. The level of significance was set at 0.05. Normal pulp tissue derived cells formed higher colonies (42.5±16.8 per 10 4 cells) than the pulp polyp (17.75±8.9 per 10 4 cells) ( P =0.015). The CD146 positive portion of the polyp derived cells formed an average of 91.5±29.7 per 10 4 cells per CFU. On the other hand, CD146 negative portion did not show any colonies ( P <0.001). Both resources showed cells with flowcytometric antigen panel and differentiation potentials conforming to MSC definition. The entire CFU of PPSCs were formed within CD146 enriched portion. It seems that CD146 enrichment may reduce the number of possible fibroblasts of the pulp polyps and may further homogenize the culture of the PPSCs.

Iloprost up-regulates vascular endothelial growth factor expression in human dental pulp cells in vitro and enhances pulpal blood flow in vivo.

PubMed

Limjeerajarus, Chalida Nakalekha; Osathanon, Thanaphum; Manokawinchoke, Jeeranan; Pavasant, Prasit

2014-07-01

Prostacyclin (PGI2) is a biomolecule capable of enhancing angiogenesis and cellular proliferation. We investigated the influence of a PGI2 analogue (iloprost) on dental pulp revascularization in vitro and in vivo by using human dental pulp cells (HDPCs) and a rat tooth injury model, respectively. Iloprost stimulated the human dental pulp cell mRNA expression of vascular endothelial growth factor (VEGF), fibroblast growth factor-2 (FGF-2), and platelet-derived growth factor (PDGF) in a significant dose-dependent manner. This mRNA up-regulation was significantly inhibited by pretreatment with a PGI2 receptor antagonist and forskolin (a protein kinase A activator). In contrast, a protein kinase A inhibitor significantly enhanced the iloprost-induced mRNA expression of VEGF, FGF-2, and PDGF. Pretreatment with a fibroblast growth factor receptor inhibitor attenuated the VEGF, FGF-2, and PDGF mRNA expression, indicating opposing regulatory mechanisms. The effect of iloprost on the dental pulp was investigated in vivo by using a rat molar pulp injury model. The iloprost-treated group exhibited a significant increase in pulpal blood flow at 72 hours compared with control. The present study indicates that iloprost may be a candidate agent to promote neovascularization in dental pulp tissue, suggesting the potential clinical use of iloprost in vital pulp therapy. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Scaffolds to Control Inflammation and Facilitate Dental Pulp Regeneration

PubMed Central

Colombo, John S.; Moore, Amanda N.; Hartgerink, Jeffrey D.; D’Souza, Rena N.

2014-01-01

In dentistry, the maintenance of a vital dental pulp is of paramount importance, as teeth devitalized by root canal treatment may become more brittle and prone to structural failure over time. Advanced carious lesions can irreversibly damage the dental pulp by propagating a sustained inflammatory response throughout the tissue. While the inflammatory response initially drives tissue repair, sustained inflammation has an enormously destructive effect on the vital pulp, eventually leading to total necrosis of the tissue and necessitating its removal. The implications of tooth devitalization have driven significant interest in the development of bioactive materials that facilitate the regeneration of damaged pulp tissues by harnessing the capacity of the dental pulp for self-repair. In considering the process by which pulpitis drives tissue destruction, it is clear that an important step in supporting the regeneration of pulpal tissues is the attenuation of inflammation. Macrophages, key mediators of the immune response, may play a critical role in the resolution of pulpitis due to their ability to switch to a pro-resolution phenotype. This process can be driven by the resolvins, a family of molecules derived from fatty acids that show great promise as therapeutic agents. In this review, we outline the importance of preserving the capacity of the dental pulp to self-repair through the rapid attenuation of inflammation. Potential treatment modalities, such as shifting macrophages to a pro-resolving phenotype with resolvins are described, and a range of materials known to support the regeneration of dental pulp are presented. PMID:24698696

The expression of hyperpolarization-activated cyclic nucleotide-gated channel 1 (HCN1) and HCN2 in the rat trigeminal ganglion, sensory root, and dental pulp.

PubMed

Cho, Y S; Kim, Y S; Moozhayil, S J; Yang, E S; Bae, Y C

2015-04-16

Hyperpolarization-activated cyclic nucleotide-gated channel 1 (HCN1) and 2 (HCN2) are abundantly expressed in primary sensory neurons and contribute to neuronal excitability and pathological pain. We studied the expression of HCN1 and HCN2 in the rat trigeminal ganglion (TG) neurons and axons in the dental pulp, and the changes in their expression following inflammation, using light- and electron-microscopic immunocytochemistry and quantitative analysis. HCN1 and HCN2 were expressed predominantly in large-sized, neurofilament 200-immunopositive (+) or parvalbumin+ soma in the TG whereas they were expressed mostly in unmyelinated and small myelinated axons in the sensory root. The expression was particularly strong along the plasma membrane in the soma. In the dental pulp, majority of HCN1+ and HCN2+ axons coexpressed calcitonin gene-related peptide. They were expressed mainly in the peripheral pulp and pulp horn where the axons branch extensively in the dental pulp. The expression of HCN1 and HCN2 in TG neurons increased significantly in rats with experimentally induced inflammation of the dental pulp. Our findings support the notion that HCN1 and HCN2 are expressed mainly by both the soma of mechanosensitive neurons in the TG and peripheral axons of nociceptive neurons in the sensory root, and may play a role in the mechanisms of inflammatory pain from the dental pulp. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Recruitment of dental pulp cells by dentine and pulp extracellular matrix components.

PubMed

Smith, J G; Smith, A J; Shelton, R M; Cooper, P R

2012-11-01

The present study aimed to determine whether dentine tissue and preparations of extracellular matrix (ECM) from pulp (pECM) and dentine (dECM), and breakdown products, influenced pulp cell migration. Chemotaxis transwell and agarose spot assays demonstrated that both dentine and pulp ECM molecules acted as chemoattractants for primary pulp cells. Chemoattractant activities of dECM and pECM were enhanced when subjected to acid and enzymatic breakdown, respectively. This enhanced activity following physiologically relevant breakdown may be pertinent to the disease environment. Pulp cell migration in response to dental ECMs was dependent on an active rho pathway. Recruited cells exhibited increased stem cell marker expression indicating that dental ECMs and their breakdown products selectively attract progenitor cells that contribute to repair processes. In conclusion, combined these results indicate that ECM molecules contribute to cell recruitment necessary for regeneration of the dentine-pulp complex after injury. Copyright © 2012 Elsevier Inc. All rights reserved.

Histological and immunohistochemical study on the dental pulp of patients with diabetes mellitus.

PubMed

Moraru, Alina Iren; GheorghiŢă, Lelia Mihaela; Dascălu, Ionela Teodora; Bătăiosu, Marilena; Manolea, Horia Octavian; Agop Forna, Doriana; Râcă, Ana Maria; RaŢiu, Cristian Adrian; Diaconu, Oana Andreea

2017-01-01

Diabetes mellitus is a disease that brings numerous alterations in the human body, mainly on the blood vessels and nervous system, its complications being difficult to treat most of the time. Oral complications are largely known and studied. Changes that occur in the dental pulp are of importance for the dentists, considering regular procedures outcome. In early stages of the disease, new blood vessels appear especially under the odontoblasts layer as a reaction to stimuli. In later stages, the defense systems of the dental pulp are outnumbered, nervous branches will be destroyed and disorganized. When periodontal disease occurs as well the mortification of the dental pulp will be faster.

Antibacterial activities of extracts from Ugandan medicinal plants used for oral care.

PubMed

Ocheng, Francis; Bwanga, Freddie; Joloba, Moses; Borg-Karlson, Ann-Karin; Gustafsson, Anders; Obua, Celestino

2014-08-08

Medicinal plants are widely used for treatment of oral/dental diseases in Uganda. To investigate antibacterial activities of 16 commonly used medicinal plants on microorganisms associated with periodontal diseases (PD) and dental caries (DC). Pulp juice and solvent extracts (hexane, methanol and water) from the plants were tested against Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia associated with PD and Streptococcus mutans, Streptococcus sobrinus, Lactobacillus acidophilus associated with DC. Tests were done using agar well-diffusion (pulp juice) and agar-dilution (Solvent extracts) assays. Pulp juice from Zanthoxylum chalybeum and Euclea latidens showed activity against all the bacteria, Zanthoxylum chalybeum being most active. Hexane extract from aerial part of Helichrysum odoratissimum was most active (MIC: 0.125-0.5 mg/ml). Methanol extract from leaves of Lantana trifolia showed activity against all bacteria (MIC: 0.25-1 mg/ml). Several of the tested plants showed antibacterial activities against bacteria associated with PD and DC, meriting further investigations. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Three-dimensional culture of dental pulp stem cells in direct contact to tricalcium silicate cements.

PubMed

Widbiller, M; Lindner, S R; Buchalla, W; Eidt, A; Hiller, K-A; Schmalz, G; Galler, K M

2016-03-01

Calcium silicate cements are biocompatible dental materials applicable in contact with vital tissue. The novel tricalcium silicate cement Biodentine™ offers properties superior to commonly used mineral trioxide aggregate (MTA). Objective of this study was to evaluate its cytocompatibility and ability to induce differentiation and mineralization in three-dimensional cultures of dental pulp stem cells after direct contact with the material. Test materials included a new tricalcium silicate (Biodentine™, Septodont, Saint-Maur-des-Fossés, France), MTA (ProRoot® MTA, DENSPLY Tulsa Dental Specialities, Johnson City, TN, USA), glass ionomer (Ketac™ Molar Aplicap™, 3M ESPE, Seefeld, Germany), human dentin disks and polystyrene. Magnetic activated cell sorting for to the surface antigen STRO-1 was performed to gain a fraction enriched with mesenchymal stem cells. Samples were allowed to set and dental pulp stem cells in collagen carriers were placed on top. Scanning electron microscopy of tricalcium silicate cement surfaces with and without cells was conducted. Cell viability was measured for 14 days by MTT assay. Alkaline phosphatase activity was evaluated (days 3, 7, and 14) and expression of mineralization-associated genes (COL1A1, ALP, DSPP, and RUNX2) was quantified by real-time quantitative PCR. Nonparametric statistical analysis for cell viability and alkaline phosphatase data was performed to compare different materials as well as time points (Mann-Whitney U test, α = 0.05). Cell viability was highest on tricalcium silicate cement, followed by MTA. Viability on glass ionomer cement and dentin disks was significantly lower. Alkaline phosphatase activity was lower in cells on new tricalcium silicate cement compared to MTA, whereas expression patterns of marker genes were alike. Increased cell viability and similar levels of mineralization-associated gene expression in three-dimensional cell cultures on the novel tricalcium silicate cement and mineral trioxide aggregate indicate that the material is cytocompatible and bioactive. The tested new tricalcium silicate cement confirms its suitability as an alternative to MTA in vital pulp therapy.

A Miniature Swine Model for Stem Cell-Based De Novo Regeneration of Dental Pulp and Dentin-Like Tissue.

PubMed

Zhu, Xiaofei; Liu, Jie; Yu, Zongdong; Chen, Chao-An; Aksel, Hacer; Azim, Adham A; Huang, George T-J

2018-02-01

The goal of this study was to establish mini-swine as a large animal model for stem cell-based pulp regeneration studies. Swine dental pulp stem cells (sDPSCs) were isolated from mini-swine and characterized in vitro. For in vivo studies, we first employed both ectopic and semi-orthotopic study models using severe combined immunodeficiency mice. One is hydroxyapatite-tricalcium phosphate (HA/TCP) model for pulp-dentin complex formation, and the other is tooth fragment model for complete pulp regeneration with new dentin depositing along the canal walls. We found that sDPSCs are similar to their human counterparts exhibiting mesenchymal stem cell characteristics with ability to form colony forming unit-fibroblastic and odontogenic differentiation potential. sDPSCs formed pulp-dentin complex in the HA/TCP model and showed pulp regeneration capacity in the tooth fragment model. We then tested orthotopic pulp regeneration on mini-swine including the use of multi-rooted teeth. Using autologous sDPSCs carried by hydrogel and transplanted into the mini-swine root canal space, we observed regeneration of vascularized pulp-like tissue with a layer of newly deposited dentin-like (rD) tissue or osteodentin along the canal walls. In some cases, dentin bridge-like structure was observed. Immunohistochemical analysis detected the expression of nestin, dentin sialophosphoprotein, dentin matrix protein 1, and bone sialoprotein in odontoblast-like cells lining against the produced rD. We also tested the use of allogeneic sDPSCs for the same procedures. Similar findings were observed in allogeneic transplantation. This study is the first to show an establishment of mini-swine as a suitable large animal model utilizing multi-rooted teeth for further cell-based pulp regeneration studies.

Overexpression of interleukin-6 and -8, cell growth inhibition and morphological changes in 2-hydroxyethyl methacrylate-treated human dental pulp mesenchymal stem cells.

PubMed

Trubiani, O; Cataldi, A; De Angelis, F; D'Arcangelo, C; Caputi, S

2012-01-01

To evaluate morphological features, cell growth and interleukin-6 (IL-6) and interleukin-8 (IL-8) secretion in expanded ex vivo human dental pulp mesenchymal stem cells (DP-MSCs) after exposure to 2-hydroxyethyl methacrylate (HEMA).   Dental pulp mesenchymal stem cells were derived from the dental pulps of 10 young donors. After in vitro isolation, DP-MSCs were treated with 3 and 5 mmol L(-1) HEMA, and after 24, 48 and 72 h of incubation, their morphological features, cell growth, IL-6 and IL-8 secretion were analysed. Differences in the cell growth and in the interleukin secretion were analysed for statistical significance with two-way anova tests and the Holm-Sidak method for multiple comparisons.   Dental pulp mesenchymal stem cells revealed a decrease in cell growth with both treatments (P < 0.05), more evident at 5 mmol L(-1) . Microscopic analysis displayed extensive cytotoxic effects in treated cells, which lost their fibroblastoid features and became retracted, even roundish, with a large number of granules. An up-regulation of IL-6 and IL-8 in treated cells cytokines was evident (P < 0.05).   2-Hydroxyethyl methacrylate exhibited cytotoxicity, inhibited cell growth and induced morphological changes in cultured DP-MSCs. Moreover, in treated samples, an up-regulation of soluble mediators of inflammation such as IL-6 and IL-8 cytokines was found. The direct application of HEMA potentially induces an inflammation process that could be the starting point for toxic response and cell damage in DP-MSCs. © 2011 International Endodontic Journal.

Regenerative Endodontics in light of the stem cell paradigm

PubMed Central

Rosa, Vinicius; Botero, Tatiana M.; Nör, Jacques E.

2013-01-01

Stem cells play a critical role in development and in tissue regeneration. The dental pulp contains a small sub-population of stem cells that are involved in the response of the pulp to caries progression. Specifically, stem cells replace odontoblasts that have undergone cell death as a consequence of the cariogenic challenge. Stem cells also secrete factors that have the potential to enhance pulp vascularization and provide the oxygen and nutrients required for the dentinogenic response that is typically observed in teeth with deep caries. However, the same angiogenic factors that are required for dentin regeneration may ultimately contribute to the demise of the pulp by enhancing vascular permeability and interstitial pressure. Recent studies focused on the biology of dental pulp stem cells revealed that the multipotency and angiogenic capacity of these cells could be exploited therapeutically in dental pulp tissue engineering. Collectively, these findings suggest new treatment paradigms in the field of Endodontics. The goal of this review is to discuss the potential impact of dental pulp stem cells to Regenerative Endodontics. PMID:21726222

An Overview of Pathogen Recognition Receptors for Innate Immunity in Dental Pulp

PubMed Central

Jang, Ji-Hyun; Shin, Hee Woong; Lee, Jung Min; Lee, Hyeon-Woo; Kim, Eun-Cheol; Park, Sang Hyuk

2015-01-01

Pathogen recognition receptors (PRRs) are a class of germ line-encoded receptors that recognize pathogen-associated molecular patterns (PAMPs). The activation of PRRs is crucial for the initiation of innate immunity, which plays a key role in first-line defense until more specific adaptive immunity is developed. PRRs differ in the signaling cascades and host responses activated by their engagement and in their tissue distribution. Currently identified PRR families are the Toll-like receptors (TLRs), the C-type lectin receptors (CLRs), the nucleotide-binding oligomerization domain-like receptors (NLRs), the retinoic acid-inducible gene-I-like receptors (RLRs), and the AIM2-like receptor (ALR). The environment of the dental pulp is substantially different from that of other tissues of the body. Dental pulp resides in a low compliance root canal system that limits the expansion of pulpal tissues during inflammatory processes. An understanding of the PRRs in dental pulp is important for immunomodulation and hence for developing therapeutic targets in the field of endodontics. Here we comprehensively review recent finding on the PRRs and the mechanisms by which innate immunity is activated. We focus on the PRRs expressed on dental pulp and periapical tissues and their role in dental pulp inflammation. PMID:26576076

Dental pulp stem cells in regenerative dentistry.

PubMed

Casagrande, Luciano; Cordeiro, Mabel M; Nör, Silvia A; Nör, Jacques E

2011-01-01

Stem cells constitute the source of differentiated cells for the generation of tissues during development, and for regeneration of tissues that are diseased or injured postnatally. In recent years, stem cell research has grown exponentially owing to the recognition that stem cell-based therapies have the potential to improve the life of patients with conditions that span from Alzheimer's disease to cardiac ischemia to bone or tooth loss. Growing evidence demonstrates that stem cells are primarily found in niches and that certain tissues contain more stem cells than others. Among these tissues, the dental pulp is considered a rich source of mesenchymal stem cells that are suitable for tissue engineering applications. It is known that dental pulp stem cells have the potential to differentiate into several cell types, including odontoblasts, neural progenitors, osteoblasts, chondrocytes, and adipocytes. The dental pulp stem cells are highly proliferative. This characteristic facilitates ex vivo expansion and enhances the translational potential of these cells. Notably, the dental pulp is arguably the most accessible source of postnatal stem cells. Collectively, the multipotency, high proliferation rates, and accessibility make the dental pulp an attractive source of mesenchymal stem cells for tissue regeneration. This review discusses fundamental concepts of stem cell biology and tissue engineering within the context of regenerative dentistry.

Glutamate control of pulpal blood flow in the incisor dental pulp of the rat.

PubMed

Zerari-Mailly, Fouzia; Braud, Adeline; Davido, Nicolas; Touré, Babacar; Azérad, Jean; Boucher, Yves

2012-10-01

Glutamate is present in primary sensory afferents innervating the dental pulp and is known to exert vasoactive effects. The aims of this study were (i) to assess pulpal blood flow (PBF) after glutamate infusion in the dental pulp and (ii) to observe the distribution of glutamatergic nerve fibers expressing the vesicular transporters of glutamate (VGluT). The PBF was monitored with laser Doppler flowmetry before and after glutamate (0.5 M) infusion in the dental pulp vs. saline infusion. Immunochemistry for VGluT1, 2, and 3 was performed in addition to immunochemistry for the vascular and neuronal markers smooth-muscle actin (SMA), isolectin B4 (IB4), and calcitonin gene-related peptide (CGRP). Glutamate infusion resulted in a PBF increase that lasted for 60 s. Positive immunolabeling was observed for the three glutamate transporters, but was more pronounced for VGluT3. Moreover, VGluT3 immunoreactivity was observed within nerve fibers entering the dental pulp and terminating at the periphery and at the vicinity of odontoblasts. Also, VGluT3 was colocalized with the vascular marker SMA, and in some nerve fibers with IB4, but not with CGRP. This study provides support for a control of dental pulp microcirculation by neurons expressing VGluT3. © 2012 Eur J Oral Sci.

Influence of moderate to severe chronic periodontitis on dental pulp.

PubMed

Fatemi, K; Disfani, R; Zare, R; Moeintaghavi, A; Ali, Saadat A; Boostani, H R

2012-10-01

The relationship between periodontal disease and dental pulp changes is controversial and has been debated for many years. This human study was performed to evaluate the possible effects of moderate to advanced periodontal disease on the different aspect of dental pulp structure. Twenty hopeless permanent teeth were extracted from systemically healthy adults because of moderate to advanced chronic periodontitis, with a bone loss of >6 mm and a mobility of grade 2 or 3. Upon extraction, the apical 2 to 3 mm of the roots were immediately sectioned. Four to five sections were mounted on each slide, and every third slide was stained with hematoxylin and eosin. The specimens were histologically processed and examined by an oral pathologist. Non-inflamed pulp, with partial or complete necrosis in some sections and several non-necrotic sections, was found in only 6.3% of teeth. Most teeth (58.3%) displayed edematous pulps. Slightly fibrotic pulps were seen in 52.1% of sections. Odontoblastic integrity was seen in 31.3% of teeth. Most teeth (77.1%) displayed no pulp stones. In 43.8% of teeth, the pulp vessels displayed dilatation. Moderate to advanced periodontal disease can affect the dental pulp. Careful consideration of diagnostic and treatment planing in patients with endodontic-periodontal involvement is therefore recommended.

Influence of moderate to severe chronic periodontitis on dental pulp

PubMed Central

Fatemi, K; Disfani, R; Zare, R; Moeintaghavi, A; Ali, Saadat A.; Boostani, H. R

2012-01-01

Background: The relationship between periodontal disease and dental pulp changes is controversial and has been debated for many years. This human study was performed to evaluate the possible effects of moderate to advanced periodontal disease on the different aspect of dental pulp structure. Materials and Methods: Twenty hopeless permanent teeth were extracted from systemically healthy adults because of moderate to advanced chronic periodontitis, with a bone loss of >6 mm and a mobility of grade 2 or 3. Upon extraction, the apical 2 to 3 mm of the roots were immediately sectioned. Four to five sections were mounted on each slide, and every third slide was stained with hematoxylin and eosin. The specimens were histologically processed and examined by an oral pathologist. Results: Non-inflamed pulp, with partial or complete necrosis in some sections and several non-necrotic sections, was found in only 6.3% of teeth. Most teeth (58.3%) displayed edematous pulps. Slightly fibrotic pulps were seen in 52.1% of sections. Odontoblastic integrity was seen in 31.3% of teeth. Most teeth (77.1%) displayed no pulp stones. In 43.8% of teeth, the pulp vessels displayed dilatation. Conclusions: Moderate to advanced periodontal disease can affect the dental pulp. Careful consideration of diagnostic and treatment planing in patients with endodontic-periodontal involvement is therefore recommended. PMID:23493524

MAPK signaling is required for LPS-induced VEGF in pulp stem cells.

PubMed

Botero, T M; Son, J S; Vodopyanov, D; Hasegawa, M; Shelburne, C E; Nör, J E

2010-03-01

Caries-induced pulpitis is typically accompanied by an increase in dental pulp microvascular density. However, the mechanisms by which dental pulp cells recognize lipopolysaccharides (LPSs) remain unclear. We hypothesized that Porphyromonas endodontalis and Escherichia coli LPSs induce vascular endothelial growth factor (VEGF) expression in dental pulp stem cells (DPSC) and human dental pulp fibroblasts (HDPF) through mitogen-activated protein kinase (MAPK) signaling. ELISA, semi-quantitative RT-PCR, immunofluorescence, and Western blots were used. Here, we observed that LPSs induced VEGF expression in DPSC and HDPF cells, and both cell types express Toll-like receptor 4 (TLR- 4). Notably, LPS-induced VEGF is associated with phosphorylation of protein kinase C (PKC zeta) and extracellular signal-regulator kinase (ERK1/2) and is dependent upon MAPK activation. Analysis of these data, collectively, unveils a signaling pathway responsible for synthesis of VEGF by pulp cells and suggests a novel therapeutic target for the management of vascular responses in teeth with pulpitis.

Pulpar temperature changes during mechanical reduction of equine cheek teeth: comparison of different motorised dental instruments, duration of treatments and use of water cooling.

PubMed

O'Leary, J M; Barnett, T P; Parkin, T D H; Dixon, P M; Barakzai, S Z

2013-05-01

Although equine motorised dental instruments are widely used, there is limited information on their thermal effect on teeth. The recently described variation in subocclusal secondary dentine depth overlying individual pulp horns may affect heat transmission to the underlying pulps. This study compared the effect of 3 different equine motorised dental instruments on the pulpar temperature of equine cheek teeth with and without the use of water cooling. It also evaluated the effect of subocclusal secondary dentine thickness on pulpar temperature changes. A thermocouple probe was inserted into the pulp horns of 188 transversely sectioned maxillary cheek teeth with its tip lying subocclusally. Pulpar temperature changes were recorded during and following the continuous use of 3 different equine motorised dental instruments (A, B and C) for sequential time periods, with and without the use of water cooling. Using motorised dental instrument B compared with either A or C increased the likelihood that the critical temperature was reached in pulps by 8.6 times. Compared with rasping for 30 s, rasping for 45, 60 and 90 s increased the likelihood that the critical temperature would be reached in pulps by 7.3, 8.9 and 24.7 times, respectively. Thicker subocclusal secondary dentine (odds ratio [OR] = 0.75/mm) and water cooling (OR = 0.14) were both protective against the likelihood of the pulp reaching the critical temperature. Prolonged rasping with motorised dental instruments increased the likelihood that a pulp would be heated above the critical temperature. Increased dentinal thickness and water cooling had protective roles in reducing pulpar heating. Motorised dental instruments have the potential to seriously damage equine pulp if used inappropriately. Higher speed motorised dental instruments should be used for less time and teeth should be water cooled during or immediately after instrument use to reduce the risk of thermal pulpar damage. © 2012 EVJ Ltd.

Repair dentinogenesis following transplantation into normal and germ-free animals.

PubMed

Inoue, T; Shimono, M

1992-01-01

The purpose of this study was to investigate the dentinogenesis of dental pulp tissue following transplantation and during regeneration in normal and germ free animals, as well as in vitro experiments. (1) Partial and complete exposure of dental pulp in germ free rats by removing the enamel and dentin of molars. (2) The central portion of rat incisor which consisted of pulp and pulp chamber were autografted into various tissues. (3) Explants of rat pulp tissue were cultured on dentin matrix. (4) Resin bonding agent, 4-META/MMA-TBB-O (Superbond), was placed directly on surgically-exposed dental pulp. (1) Dentin bridge formation was recognized at 5 days after operation in germ free rat. (2) The cut surface of the transplant exhibited dentin bridge at 7 days after implantation, and the thickness of the newly formed dentin increased gradually thereafter up to 30 days. (3) Cultured pulp cells had high alkaline phosphatase activity and bone- or dentin-like hard tissue was synthesized on the dentin matrix in vitro. (4) Dentin bridge formation was evident on the surgically-exposed dental pulp even after application of Superbond. From these results, it is suggested that pulp tissue has a high activity of dentinogenesis both in vivo and in vitro and 3 days is enough for pulp cells to express the odontoblast phenotype when inflammatory factors are not present.

Cytotoxic effects of glass ionomer cements on human dental pulp stem cells correlate with fluoride release.

PubMed

Kanjevac, Tatjana; Milovanovic, Marija; Volarevic, Vladislav; Lukic, Miodrag L; Arsenijevic, Nebojsa; Markovic, Dejan; Zdravkovic, Nebojsa; Tesic, Zivoslav; Lukic, Aleksandra

2012-01-01

Glass ionomer cements (GICs) are commonly used as restorative materials. Responses to GICs differ among cell types and it is therefore of importance to thoroughly investigate the influence of these restorative materials on pulp stem cells that are potential source for dental tissue regeneration. Eight biomaterials were tested: Fuji I, Fuji II, Fuji VIII, Fuji IX, Fuji Plus, Fuji Triage, Vitrebond and Composit. We compared their cytotoxic activity on human dental pulp stem cells (DPSC) and correlated this activity with the content of Fluoride, Aluminium and Strontium ions in their eluates. Elution samples of biomaterials were prepared in sterile tissue culture medium and the medium was tested for toxicity by an assay of cell survival/proliferation (MTT test) and apoptosis (Annexin V FITC Detection Kit). Concentrations of Fluoride, Aluminium and Strontium ions were tested by appropriate methods in the same eluates. Cell survival ranged between 79.62% (Fuji Triage) to 1.5% (Fuji Plus) and most dead DPSCs were in the stage of late apoptosis. Fluoride release correlated with cytotoxicity of GICs, while Aluminium and Strontium ions, present in significant amount in eluates of tested GICs did not. Fuji Plus, Vitrebond and Fuji VIII, which released fluoride in higher quantities than other GICs, were highly toxic to human DPSCs. Opposite, low levels of released fluoride correlated to low cytotoxic effect of Composit, Fuji I and Fuji Triage.

Photoacoustic microscopy of human teeth

NASA Astrophysics Data System (ADS)

Rao, Bin; Cai, Xin; Favazza, Christopher; Yao, Junjie; Li, Li; Duong, Steven; Liaw, Lih-Huei; Holtzman, Jennifer; Wilder-Smith, Petra; Wang, Lihong V.

2011-03-01

Photoacoustic microscopy (PAM) utilizes short laser pulses to deposit energy into light absorbers and sensitively detects the ultrasonic waves the absorbers generate in response. PAM directly renders a three-dimensional spatial distribution of sub-surface optical absorbers. Unlike other optical imaging technologies, PAM features label-free optical absorption contrast and excellent imaging depths. Standard dental imaging instruments are limited to X-ray and CCD cameras. Subsurface optical dental imaging is difficult due to the highly-scattering enamel and dentin tissue. Thus, very few imaging methods can detect dental decay or diagnose dental pulp, which is the innermost part of the tooth, containing the nerves, blood vessels, and other cells. Here, we conducted a feasibility study on imaging dental decay and dental pulp with PAM. Our results showed that PAM is sensitive to the color change associated with dental decay. Although the relative PA signal distribution may be affected by surface contours and subsurface reflections from deeper dental tissue, monitoring changes in the PA signals (at the same site) over time is necessary to identify the progress of dental decay. Our results also showed that deep-imaging, near-infrared (NIR) PAM can sensitively image blood in the dental pulp of an in vitro tooth. In conclusion, PAM is a promising tool for imaging both dental decay and dental pulp.

Dental pulp neurophysiology: part 2. Current diagnostic tests to assess pulp vitality.

PubMed

Abd-Elmeguid, Ashraf; Yu, Donald C

2009-03-01

In this second part of our 2-part review, we discuss recent research about pulp tests that determine the vitality of the tooth and clinically accepted pulp testers. A pain response to hot, cold or an electric pulp tester indicates the vitality of only a tooth's pulpal sensory supply; the response does not give any idea about the state of the pulp. Although the sensitivity of these tests is high, when false-positive and false-negative results occur, they may affect the treatment of the tooth. A tooth falsely diagnosed as nonvital with an electric pulp tester may undergo an unnecessary root canal, whereas one falsely diagnosed as vital may be left untreated, causing the necrotic tissue to destroy the supporting tissues (resorption). The vascular supply is more important to the determination of the health of the pulp than the sensory supply. Pulp death is caused by cessation of blood flow and may result in a necrotic pulp, even though the pulpal sensory supply may still be viable. The pulp can be healed only if the circulating blood flow is healthy. Although still under investigation, diagnostic devices that examine pulpal blood flow, such as the pulse oximeter and laser Doppler flowmetry, show promising results for the assessment of pulp vitality.

Stem/progenitor cells from inflamed human dental pulp retain tissue regeneration potential

PubMed Central

Alongi, Dominick J; Yamaza, Takayoshi; Song, Yingjie; Fouad, Ashraf F; Romberg, Elaine E; Shi, Songtao; Tuan, Rocky S; Huang, George T-J

2011-01-01

Background Potent stem/progenitor cells have been isolated from normal human dental pulps termed dental pulp stem cells (DPSCs). However, it is unknown whether these cells exist in inflamed pulps (IPs). Aims To determine whether DPSCs can be identified and isolated from IPs; and if they can be successfully cultured, whether they retain tissue regeneration potential in vivo. Materials & methods DPSCs from freshly collected normal pulps (NPs) and IPs were characterized in vitro and their tissue regeneration potential tested using an in vivo study model. Results The immunohistochemical analysis showed that IPs expressed higher levels of mesenchymal stem cell markers STRO-1, CD90, CD105 and CD146 compared with NPs (p < 0.05). Flow cytometry analysis showed that DPSCs from both NPs and IPs expressed moderate to high levels of CD146, stage-specific embryonic antigen-4, CD73 and CD166. Total population doubling of DPSCs-IPs (44.6 ± 2.9) was lower than that of DPSCs-NPs (58.9 ± 2.5) (p < 0.05), and DPSCs-IPs appeared to have a decreased osteo/dentinogenic potential compared with DPSCs-NPs based on the mineral deposition in cultures. Nonetheless, DPSCs-IPs formed pulp/dentin complexes similar to DPSCs-NPs when transplanted into immunocompromised mice. Conclusion DPSCs-IPs can be isolated and their mesenchymal stem cell marker profiles are similar to those from NPs. Although some stem cell properties of DPSCs-IPs were altered, cells from some samples remained potent in tissue regeneration in vivo. PMID:20465527

Comparative evaluation of the isolation and quantification of stem cells derived from dental pulp and periodontal ligament of a permanent tooth and to assess their viability and proliferation on a platelet-rich fibrin scaffold

PubMed Central

Khurana, Rohit; Kudva, Praveen Bhasker; Husain, Syed Yawer

2017-01-01

Background: The present study aims to comparatively evaluate the isolation and quantification of stem cells derived from dental pulp and periodontal ligament of a permanent tooth and to assess their viability and proliferation on a platelet-rich fibrin (PRF) scaffold. Materials and Methods: A total of 15 systemically healthy individuals between the age group of 15–25 years requiring third molar or orthodontic premolar extractions. Teeth were extracted atraumatically and transported to the laboratory. Stem cells were isolated from dental pulp and periodontal ligament. After attaining more than 90% confluency by the 7th day, these cells were tested for their viability and characterization. Stem cells were also incubated with PRF and viability was assessed on the 7th day. Results: The mean number of cell for dental pulp stem cells (DPSCs) and periodontal ligament stem cell (PDLSC) was statistically insignificant (P > 0.05). The mean live cell viability was compared between DPSC (98.07%) and PDLSC (98%). Both DPSC and PDLSC showed a high percentage of expression of CD73 markers, 30.40% and 29.80%, respectively. However, DPSCs and PDLSCs lacked expression of CD34 expressing only 3.47% and 3.53%, respectively. PRF membrane as a scaffold exhibited no cytotoxic effects on DPCS's or PDLSC's. The cell viability of cells cultured with PRF was statistically insignificant (P > 0.05) when compared to the cells cultured with culture media. Conclusion: The study thus indicates that dental pulp and periodontal ligament are both rich sources of mesenchymal stem cells and can be successfully used for obtaining stem cells. PRF exhibits no cytotoxic effects on the cells and can be used in conjunction with dental stem cells. PMID:29386795

Characterization of Coronal Pulp Cells and Radicular Pulp Cells in Human Teeth.

PubMed

Honda, Masaki; Sato, Momoko; Toriumi, Taku

2017-09-01

Dental pulp has garnered much attention as an easily accessible postnatal tissue source of high-quality mesenchymal stem cells (MSCs). Since the discovery of dental pulp stem cells (DPSCs) in permanent third molars, stem cells from human exfoliated deciduous teeth and from supernumerary teeth (mesiodentes) have been identified as a population distinct from DPSCs. Dental pulp is divided into 2 parts based on the developing stage: the coronal pulp and the radicular pulp. Root formation begins after the crown part is completed. We performed a sequential study to examine the differences between the characteristics of coronal pulp cells (CPCs) and radicular pulp cells (RPCs) from permanent teeth, mesiodentes, and deciduous teeth. Interestingly, although we have not obtained any data on the difference between CPCs and RPCs in permanent teeth, there are some differences between the characteristics of CPCs and RPCs from mesiodentes and deciduous teeth. The MSC characteristics differed between the RPCs and CPCs, and the reprogramming efficiency for the generation of induced pluripotent stem cells was greater in RPCs than in CPCs from deciduous teeth. The proportion of CD105 + cells in CPCs versus that in RPCs varied in mesiodentes but not in permanent teeth. The results indicate that the proportion of CD105 + cells is an effective means of characterizing dental pulp cells in mesiodentes. Taken together, the stem cells in deciduous and supernumerary teeth share many characteristics, such as a high proliferation rate and an immunophenotype similar to that of DPSCs. Thus, mesiodentes accidentally encountered on radiographs by the general dental practitioner might be useful for stem cell therapy. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Human dental pulp pluripotent-like stem cells promote wound healing and muscle regeneration.

PubMed

Martínez-Sarrà, Ester; Montori, Sheyla; Gil-Recio, Carlos; Núñez-Toldrà, Raquel; Costamagna, Domiziana; Rotini, Alessio; Atari, Maher; Luttun, Aernout; Sampaolesi, Maurilio

2017-07-27

Dental pulp represents an easily accessible autologous source of adult stem cells. A subset of these cells, named dental pulp pluripotent-like stem cells (DPPSC), shows high plasticity and can undergo multiple population doublings, making DPPSC an appealing tool for tissue repair or maintenance. DPPSC were harvested from the dental pulp of third molars extracted from young patients. Growth factors released by DPPSC were analysed using antibody arrays. Cells were cultured in specific differentiation media and their endothelial, smooth and skeletal muscle differentiation potential was evaluated. The therapeutic potential of DPPSC was tested in a wound healing mouse model and in two genetic mouse models of muscular dystrophy (Scid/mdx and Sgcb-null Rag2-null γc-null). DPPSC secreted several growth factors involved in angiogenesis and extracellular matrix deposition and improved vascularisation in all three murine models. Moreover, DPPSC stimulated re-epithelialisation and ameliorated collagen deposition and organisation in healing wounds. In dystrophic mice, DPPSC engrafted in the skeletal muscle of both dystrophic murine models and showed integration in muscular fibres and vessels. In addition, DPPSC treatment resulted in reduced fibrosis and collagen content, larger cross-sectional area of type II fast-glycolytic fibres and infiltration of higher numbers of proangiogenic CD206 + macrophages. Overall, DPPSC represent a potential source of stem cells to enhance the wound healing process and slow down dystrophic muscle degeneration.

Evaluation of thermal cooling mechanisms for laser application to teeth.

PubMed

Miserendino, L J; Abt, E; Wigdor, H; Miserendino, C A

1993-01-01

Experimental cooling methods for the prevention of thermal damage to dental pulp during laser application to teeth were compared to conventional treatment in vitro. Pulp temperature measurements were made via electrical thermistors implanted within the pulp chambers of extracted human third molar teeth. Experimental treatments consisted of lasing without cooling, lasing with cooling, laser pulsing, and high-speed dental rotary drilling. Comparisons of pulp temperature elevation measurements for each group demonstrated that cooling by an air and water spray during lasing significantly reduced heat transfer to dental pulp. Laser exposures followed by an air and water spray resulted in pulp temperature changes comparable to conventional treatment by drilling. Cooling by an air water spray with evacuation appears to be an effective method for the prevention of thermal damage to vital teeth following laser exposure.

Dual ECM Biomimetic Scaffolds for Dental Pulp Regenerative Applications

PubMed Central

Huang, Chun-Chieh; Narayanan, Raghuvaran; Warshawsky, Noah; Ravindran, Sriram

2018-01-01

Dental pulp is a highly vascularized and innervated tissue that provides sensitivity and vitality to the tooth. Chronic caries results in an infected pulp tissue prone to necrosis. Existing clinical treatments replace the living pulp tissue with a non-responsive resin filling resulting in loss of tooth vitality. Tissue engineering approaches to dental pulp tissue regeneration have been investigated to preserve tooth vitality and function. However, a critical criterion is the choice of growth factors that may promote mesenchymal stem cell differentiation and more importantly, vascularization. But, the problems associated with growth factor dosage, delivery, safety, immunological and ectopic complications affect their translatory potential severely. The purpose of this study is to develop, characterize and evaluate a biomimetic native extracellular matrix (ECM) derived dual ECM scaffold that consists of a pulp-specific ECM to promote MSC attachment, proliferation and differentiation and an endothelial ECM to promote migration of host endothelial cells and eventual vascularization in vivo. Our results show that the dual ECM scaffolds possess similar properties as a pulp-ECM scaffold to promote MSC attachment and odontogenic differentiation in vitro. Additionally, when implanted subcutaneously in a tooth root slice model in vivo, the dual ECM scaffolds promoted robust odontogenic differentiation of both dental pulp and bone marrow derived MSCs and also extensive vascularization when compared to respective controls. These scaffolds are mass producible for clinical use and hence have the potential to replace root canal therapy as a treatment for chronic dental caries. PMID:29887803

Transforming growth factor-β-induced gene product-h3 inhibits odontoblastic differentiation of dental pulp cells.

PubMed

Serita, Suguru; Tomokiyo, Atsushi; Hasegawa, Daigaku; Hamano, Sayuri; Sugii, Hideki; Yoshida, Shinichiro; Mizumachi, Hiroyuki; Mitarai, Hiromi; Monnouchi, Satoshi; Wada, Naohisa; Maeda, Hidefumi

2017-06-01

The aim of this study was to investigate transforming growth factor-β-induced gene product-h3 (βig-h3) expression in dental pulp tissue and its effects on odontoblastic differentiation of dental pulp cells (DPCs). A rat direct pulp capping model was prepared using perforated rat upper first molars capped with mineral trioxide aggregate cement. Human DPCs (HDPCs) were isolated from extracted teeth. βig-h3 expression in rat dental pulp tissue and HDPCs was assessed by immunostaining. Mineralization of HDPCs was assessed by Alizarin red-S staining. Odontoblast-related gene expression in HDPCs was analyzed by quantitative RT-PCR. Expression of βig-h3 was detected in rat dental pulp tissue, and attenuated by direct pulp capping, while expression of interleukin-1β and tumor necrosis factor-α was increased in exposed pulp tissue. βig-h3 expression was also detected in HDPCs, with reduced expression during odontoblastic differentiation. The above cytokines reduced βig-h3 expression in HDPCs, and promoted their mineralization. Recombinant βig-h3 inhibited the expression of odontoblast-related genes and mineralization of HDPCs, while knockdown of βig-h3 gene expression promoted the expression of odontoblast-related genes in HDPCs. The present findings suggest that βig-h3 in DPCs may be involved in reparative dentin formation and that its expression is likely to negatively regulate this process. Copyright © 2017 Elsevier Ltd. All rights reserved.

Schwann Cell Phenotype Changes in Aging Human Dental Pulp.

PubMed

Couve, E; Lovera, M; Suzuki, K; Schmachtenberg, O

2018-03-01

Schwann cells are glial cells that support axonal development, maintenance, defense, and regeneration in the peripheral nervous system. There is limited knowledge regarding the organization, plasticity, and aging of Schwann cells within the dental pulp in adult permanent teeth. The present study sought to relate changes in the pattern of Schwann cell phenotypes between young and old adult teeth with neuronal, immune, and vascular components of the dental pulp. Schwann cells are shown to form a prominent glial network at the dentin-pulp interface, consisting of nonmyelinating and myelinating phenotypes, forming a multicellular neuroimmune interface in association with nerve fibers and dendritic cells. Schwann cell phenotypes are recognized by the expression of S100, glial fibrillary acidic protein (GFAP), myelin basic protein (MBP), Sox10, GAP43, and p75NTR markers. In young adult teeth, a dense population of nonmyelinating Schwann cells projects processes in close association with sensory nerve terminals through the odontoblast layer, reaching the adjacent predentin/dentin domain. While GAP43 and p75NTR are highly expressed in nonmyelinating Schwann cells from young adult teeth, the presence of these markers declines significantly in old adult teeth. Myelinated axons, identified by MBP expression, are mainly present at the Raschkow plexus and within nerve bundles in the dental pulp, but their density is significantly reduced in old adult versus young adult teeth. These data reveal age-related changes within the glial network of the dental pulp, in association with a reduction of coronal dental pulp innervation in old adult versus young adult teeth. The prominence of Schwann cells as a cellular component at the dentin-pulp interface supports the notion that their association with sensory nerve terminals and immune system components forms part of an integrated multicellular barrier for defense against pathogens and dentin repair.

Isolation, Characterization, and Differentiation of Dental Pulp Stem Cells in Ferrets.

PubMed

Homayounfar, Negar; Verma, Prashant; Nosrat, Ali; El Ayachi, Ikbale; Yu, Zongdong; Romberg, Elaine; Huang, George T-J; Fouad, Ashraf F

2016-03-01

The ferret canine tooth has been introduced as a suitable model for studying dental pulp regeneration. The aim of this study was to isolate and characterize ferret dental pulp stem cells (fDPSCs) and their differentiation potential. Dental pulp stem cells were isolated from freshly extracted ferret canine teeth. The cells were examined for the expression of stem cell markers STRO-1, CD90, CD105, and CD146. The osteo/odontogenic and adipogenic differentiation potential of fDPSCs was evaluated. Osteogenic and odontogenic marker genes were evaluated using quantitative real-time polymerase chain reaction (qRT-PCR) on days 1, 4, and 8 after osteo/odontogenic induction of fDPSCs including dentin sialophosphoprotein (DSPP), dentin matrix protein-1, osteopontin, and alkaline phosphatase. Human dental pulp cells were used as the control. The results were analyzed using 3-way analysis of variance. fDPSCs were positive for STRO1, CD90, and CD105 and negative for CD146 markers with immunohistochemistry. fDPSCs showed strong osteogenic and weak adipogenic potential. The overall expression of DSPP was not significantly different between fDPSCs and human dental pulp cells. The expression of DSPP in osteo/odontogenic media was significantly higher in fDPSCs on day 4 (P < .01). The overall expression of dentin matrix protein-1, osteopontin, and alkaline phosphatase was significantly higher in fDPSCs (P = .0005). fDPSCs were positive for several markers of dental pulp stem cells resembling human DPSCs and appeared to show a stronger potential to differentiate to osteoblastic rather than odontoblastic lineage. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Active Nanomaterials to Meet the Challenge of Dental Pulp Regeneration

PubMed Central

Keller, Laetitia; Offner, Damien; Schwinté, Pascale; Morand, David; Wagner, Quentin; Gros, Catherine; Bornert, Fabien; Bahi, Sophie; Musset, Anne-Marie; Benkirane-Jessel, Nadia; Fioretti, Florence

2015-01-01

The vitality of the pulp is fundamental to the functional life of the tooth. For this aim, active and living biomaterials are required to avoid the current drastic treatment, which is the removal of all the cellular and molecular content regardless of its regenerative potential. The regeneration of the pulp tissue is the dream of many generations of dental surgeons and will revolutionize clinical practices. Recently, the potential of the regenerative medicine field suggests that it would be possible to achieve such complex regeneration. Indeed, three crucial steps are needed: the control of infection and inflammation and the regeneration of lost pulp tissues. For regenerative medicine, in particular for dental pulp regeneration, the use of nano-structured biomaterials becomes decisive. Nano-designed materials allow the concentration of many different functions in a small volume, the increase in the quality of targeting, as well as the control of cost and delivery of active molecules. Nanomaterials based on extracellular mimetic nanostructure and functionalized with multi-active therapeutics appear essential to reverse infection and inflammation and concomitantly to orchestrate pulp cell colonization and differentiation. This novel generation of nanomaterials seems very promising to meet the challenge of the complex dental pulp regeneration. PMID:28793649

A Customized Self-Assembling Peptide Hydrogel for Dental Pulp Tissue Engineering

PubMed Central

Hartgerink, Jeffrey D.; Cavender, Adriana C.; Schmalz, Gottfried

2012-01-01

Root canal therapy is common practice in dentistry. During this procedure, the inflamed or necrotic dental pulp is removed and replaced with a synthetic material. However, recent research provides evidence that engineering of dental pulp and dentin is possible by using biologically driven approaches. As tissue engineering strategies hold the promise to soon supersede conventional root canal treatment, there is a need for customized scaffolds for stem cell delivery or recruitment. We hypothesize that the incorporation of dental pulp-derived stem cells with bioactive factors into such a scaffold can promote cell proliferation, differentiation, and angiogenesis. In this study, we used a cell adhesive, enzyme-cleavable hydrogel made from self-assembling peptide nanofibers to encapsulate dental pulp stem cells. The growth factors (GFs) fibroblast growth factor basic, transforming growth factor β1, and vascular endothelial growth factor were incorporated into the hydrogel via heparin binding. Release profiles were established, and the influence of GFs on cell morphology and proliferation was assessed to confirm their bioactivity after binding and subsequent release. Cell morphology and spreading in three-dimensional cultures were visualized by using cell tracker and histologic stains. Subcutaneous transplantation of the hydrogel within dentin cylinders into immunocompromised mice led to the formation of a vascularized soft connective tissue similar to dental pulp. These data support the use of this novel biomaterial as a highly promising candidate for future treatment concepts in regenerative endodontics. PMID:21827280

Cell-derived micro-environment helps dental pulp stem cells promote dental pulp regeneration.

PubMed

Zhang, Xuexin; Li, Hui; Sun, Jingjing; Luo, Xiangyou; Yang, Hefeng; Xie, Li; Yang, Bo; Guo, Weihua; Tian, Weidong

2017-10-01

The function of the dental pulp is closely connected to the extracellular matrix (ECM) structure, and ECM has received significant attention due to its biological functions for regulating cells. As such, the interaction between the ECM niche and cells is worth exploring for potential clinical uses. In this study, dental pulp stem cell (DPSC)-derived ECM (DPM) was prepared through cell culture and decellularization to function as the cell niche, and changes in DPSC behaviour and histological analysis of dental pulp tissue regeneration were evaluated following the DPM culture. DPM promoted the replication of DPSCs and exhibited retention of their mineralization. Then, the DPM-based culture strategy under odontogenic culture medium was further investigated, and the mineralization-related markers showed that DPSCs were regulated towards odontogenic differentiation. Dental pulp-like tissue with well-arranged ECM was harvested after a 2-month subcutaneous implantation in nude mice with DPM application. Additionally, DPSCs cultured on the plastic culture surface showed the up-regulation of mineralization makers in vitro, but there was a disorder in matrix formation and mineralization when the cells were cultured in vivo. DPM-based cultivation could serve as a cell niche and modulate DPSC behaviour, and this method also provided an alternative to harvest tissue-specific ECM and provided a strategy for ECM-cell interaction. © 2017 John Wiley & Sons Ltd.

Human intrabony defect regeneration with micro-grafts containing dental pulp stem cells: A randomized controlled clinical trial.

PubMed

Ferrarotti, Francesco; Romano, Federica; Gamba, Mara Noemi; Quirico, Andrea; Giraudi, Marta; Audagna, Martina; Aimetti, Mario

2018-05-19

The goal of this study was to evaluate if dental pulp stem cells (DPSCs) delivered into intrabony defects in a collagen scaffold would enhance the clinical and radiographic parameters of periodontal regeneration. In this randomized controlled trial, 29 chronic periodontitis patients presenting one deep intrabony defect and requiring extraction of one vital tooth were consecutively enrolled. Defects were randomly assigned to test or control treatments which both consisted of the use of minimally invasive surgical technique. The dental pulp of the extracted tooth was mechanically dissociated to obtain micro-grafts rich in autologous DPSCs. Test sites (n=15) were filled with micro-grafts seeded onto collagen sponge, whereas control sites (n=14) with collagen sponge alone. Clinical and radiographic parameters were recorded at baseline, 6 and 12 months postoperatively. Test sites exhibited significantly more PD reduction (4.9 mm versus 3.4 mm), CAL gain (4.5 versus 2.9 mm) and bone defect fill (3.9 versus 1.6 mm) than controls. Moreover, residual PD < 5 mm (93% versus 50%) and CAL gain ≥ 4 mm (73% versus 29%) was significantly more frequent in the test group. Application of DPSCs significantly improved clinical parameters of periodontal regeneration one year after treatment. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Effects of Various Dental Materials on Alkaline Phosphatase Extracted from Pulp: An Experiment for the Biochemistry Laboratory.

ERIC Educational Resources Information Center

Thompson, Lorin R.

1980-01-01

A laboratory experiment that demonstrates the effects of various dental materials on a representative enzyme from the pulp is outlined. The experiment encourages students to consider the effects that various restorative materials and techniques might have on enzymes in the living pulp. (Author/MLW)

Transplantation of human immature dental pulp stem cell in dogs with chronic spinal cord injury.

PubMed

Feitosa, Matheus Levi Tajra; Sarmento, Carlos Alberto Palmeira; Bocabello, Renato Zonzini; Beltrão-Braga, Patrícia Cristina Baleeiro; Pignatari, Graciela Conceição; Giglio, Robson Fortes; Miglino, Maria Angelica; Orlandin, Jéssica Rodrigues; Ambrósio, Carlos Eduardo

2017-07-01

To investigate the therapeutic potential of human immature dental pulp stem cells in the treatment of chronic spinal cord injury in dogs. Three dogs of different breeds with chronic SCI were presented as animal clinical cases. Human immature dental pulp stem cells were injected at three points into the spinal cord, and the animals were evaluated by limb function and magnetic resonance imaging (MRI) pre and post-operative. There was significant improvement from the limb function evaluated by Olby Scale, though it was not supported by the imaging data provided by MRI and clinical sign and evaluation. Human dental pulp stem cell therapy presents promising clinical results in dogs with chronic spinal cord injuries, if used in association with physical therapy.

Correlation between Histological Status of the Pulp and Its Response to Sensibility Tests

PubMed Central

Naseri, Mandana; Khayat, Akbar; Zamaheni, Sara; Shojaeian, Shiva

2017-01-01

Introduction: The purpose of this study was to assess the accuracy of sensibility tests by correlating it with histologic pulp condition. Methods and Materials: Assessment of clinical signs and symptoms were performed on 65 permanent teeth that were scheduled to be extracted for periodontal, prosthodontic or orthodontic reasons. The normal pulp and reversible pulpitis were considered as treatable tooth conditions while irreversible pulpitis and necrosis were considered as untreatable conditions. The teeth were then extracted and sectioned for histological analysis of dental pulp. Histologic status and classification corresponded to the treatable or untreatable pulp condition. Comparisons between histological treatable and untreatable pulp condition were performed with chi-square analysis for sensibility test responses. The positive predictive value (PPV), negative predictive value (NPV) and accuracy to detect untreatable from treatable pulp condition were calculated for each test. Results: A significant difference was detected in the normal and a sharp lingered response to heat and cold tests. There was significant difference in the negative response to EPT between histological groups. The kappa agreement coefficient between clinical and histological diagnosis of pulp condition was about 0.843 (P<0.001). The accuracy of cold and heat tests and EPT to detect treatable pulp or untreatable pulp states were 78, 74 and 62%, respectively. The sensibility tests diagnosed untreatable pulpitis with a higher probability (NPV=63%-67% -54%, PPV=83%-91% -95% for heat, cold and EPT, respectively). Conclusion: Sensibility test results were more likely to diagnose pulpal disease or untreatable pulp conditions. However, to increase the diagnostic accuracy patient history, clinical signs and symptoms and also radiographic findings in conjunction with sensibility tests must be used. The result of this small study demonstrated a good agreement between clinical and histological pulp diagnosis. PMID:28179918

Tooth coronal index and pulp/tooth ratio in dental age estimation on digital panoramic radiographs-A comparative study.

PubMed

Jain, Supreet; Nagi, Ravleen; Daga, Minal; Shandilya, Ashutosh; Shukla, Aastha; Parakh, Abhinav; Laheji, Afshan; Singh, Rahul

2017-08-01

Assessment of an age of an individual whether living or dead through teeth is one of the most reliable and simple method to calculate age than skeletal remains especially when they are in poor conditions. The study was carried out with aim of (i) to evaluate reliability of dental age assessment through two different methods for adults i.e. tooth coronal index and pulp/tooth ratio using digital panoramic radiographs and (ii) to compare these methods for their accuracy in age determination. The digital panoramic radiographs of 180 subjects of Chhattisgarh aged 15-70 years were selected for the study. The measurements were performed on the JPEG images of selected panoramic radiographs by using Adobe Acrobat 7.0 professional software. For tooth coronal index (TCI), height of the crown i.e. coronal height (CH) and the height of the coronal pulp cavity i.e. coronal pulp cavity height (CPCH) of mandibular second premolars and first molars was measured in millimeter (mm) and then TCI was calculated for each tooth and calculated age was compared with chronological age. For pulp/tooth ratio, the measurements of pulp chamber height (PCH) and crown root trunk height (CRTH) were performed on the mandibular first and second molar teeth, the pulp chamber crown root trunk height ratios (PCTHR) of selected tooth were calculated. The acquired data were subjected to Pearson correlation test, unpaired t test and Analysis of Variance (ANOVA) analysis. Results suggested that TCI (mandibular first molar r=-0.178), second premolar (r=-0.187) and PCTHR(mandibular first molar r=-0.921, second molar r=-0.901) correlated negatively with chronological age suggesting decrease in size of pulp cavity. Mandibular first molar was found to be most reliable tooth to estimate dental age. The study showed that both PCTHR and TCI have negative association with chronological age. PCTHR showed slightly higher negative correlation and proved as a better tool for age estimation than TCI. Statistically significant differences were observed between chronological and calculated age by both methods thus emphasizing the need for future clinical trials. Copyright © 2017 Elsevier B.V. All rights reserved.

IGF-1 and TGF-β stimulate cystine/glutamate exchange activity in dental pulp cells

PubMed Central

Pauly, Katherine; Fritz, Kimberly; Furey, Alyssa; Lobner, Doug

2011-01-01

Introduction The growth factors IGF-1 and TGF-β are protective to dental pulp cells in culture against the toxicity of the composite materials Durafill VS and Flow Line. Since the toxicity of these materials is mediated by oxidative stress, it seemed possible that the protective effects of IGF-1 and TGF-β were through enhancement of an endogenous antioxidant mechanism. Methods We used cultured dental pulp cells to determine the mechanism of the protective effects of IGF-1 and TGF-β, focusing on the glutathione system and the role of cystine/glutamate exchange (system xc-). Results We found that the toxicity of Durafill VS and Flow Line was attenuated by addition of glutathione monoethylester, suggesting a specific role for the cellular antioxidant glutathione. Supporting this hypothesis we found that IGF-1 and TGF-β were protective against the toxicity of the glutathione synthesis inhibitor buthionine sulfoximine. Since levels of cellular cystine are the limiting factor in the production of glutathione we tested the effects of IGF-1 and TGF-β on cystine uptake. Both growth factors stimulated system xc- mediated cystine uptake. Furthermore, they attenuated the glutathione depletion induced by Durafill VS and Flow Line. Conclusions The results suggest that IGF-1 and TGF-β are protective through the stimulation of system xc- mediated cystine uptake leading to maintenance of cellular glutathione. This novel action of growth factors on dental pulp cells has implications not only for preventing toxicity of dental materials but also for the general function of these cells. PMID:21689549

Pulp Obliteration in a Patient with Sclerodermatous Chronic Graft-versus-Host Disease.

PubMed

Gomes, Camilla Borges Ferreira; Treister, Nathaniel Simon; Miller, Brian; Armand, Philippe; Friedland, Bernard

2016-04-01

Dental pulp calcification is a common finding associated with localized dental trauma, genetic disorders, and systemic inflammatory diseases. Chronic graft-versus-host disease (cGVHD) is a frequent complication after allogeneic hematopoietic cell transplantation (allo-HCT) characterized by immune-mediated injury to the skin, mouth, eyes, liver, and other tissues, resulting in significant disability and reduced quality of life. We report a patient with sclerodermatous cGVHD who presented with general pulp calcification in all teeth 5 years after allo-HCT. A review of full mouth dental radiographs obtained just before allo-HCT revealed normal-appearing pulp chambers. Based on prior reports of generalized pulp calcification associated with progressive systemic sclerosis, we hypothesized that the etiology was likely related to the presence of cGVHD with associated vascular and fibrotic tissue changes within the pulp vasculature. Clinicians should consider cGVHD in the differential diagnosis of generalized pulp calcification. Copyright © 2016 American Association of Endodontists. All rights reserved.

Sodium channel Nav1.7 immunoreactivity in painful human dental pulp and burning mouth syndrome

PubMed Central

2010-01-01

Background Voltage gated sodium channels Nav1.7 are involved in nociceptor nerve action potentials and are known to affect pain sensitivity in clinical genetic disorders. Aims and Objectives To study Nav1.7 levels in dental pulpitis pain, an inflammatory condition, and burning mouth syndrome (BMS), considered a neuropathic orofacial pain disorder. Methods Two groups of patients were recruited for this study. One group consisted of patients with dental pulpitis pain (n = 5) and controls (n = 12), and the other patients with BMS (n = 7) and controls (n = 10). BMS patients were diagnosed according to the International Association for the Study of Pain criteria; a pain history was collected, including the visual analogue scale (VAS). Immunohistochemistry with visual intensity and computer image analysis were used to evaluate levels of Nav1.7 in dental pulp tissue samples from the dental pulpitis group, and tongue biopsies from the BMS group. Results There was a significantly increased visual intensity score for Nav1.7 in nerve fibres in the painful dental pulp specimens, compared to controls. Image analysis showed a trend for an increase of the Nav1.7 immunoreactive % area in the painful pulp group, but this was not statistically significant. When expressed as a ratio of the neurofilament % area, there was a strong trend for an increase of Nav1.7 in the painful pulp group. Nav1.7 immunoreactive fibres were seen in abundance in the sub-mucosal layer of tongue biopsies, with no significant difference between BMS and controls. Conclusion Nav1.7 sodium channel may play a significant role in inflammatory dental pain. Clinical trials with selective Nav1.7 channel blockers should prioritise dental pulp pain rather than BMS. PMID:20529324

Melatonin attenuates inflammation of acute pulpitis subjected to dental pulp injury

PubMed Central

Li, Ji-Guo; Lin, Jia-Ji; Wang, Zhao-Ling; Cai, Wen-Ke; Wang, Pei-Na; Jia, Qian; Zhang, An-Sheng; Wu, Gao-Yi; Zhu, Guo-Xiong; Ni, Long-Xing

2015-01-01

Acute pulpitis (AP), one of the most common diseases in the endodontics, usually causes severe pain to the patients, which makes the search for therapeutic target of AP essential in clinic. Toll-like receptor 4 (TLR4) signaling is widely involved in the mechanism of pulp inflammation, while melatonin has been reported to have an inhibition for a various kinds of inflammation. We hereby studied whether melatonin can regulate the expression of TLR4/NF-ĸB signaling in the pulp tissue of AP and in human dental pulp cells (HDPCs). Two left dental pulps of the adult rat were drilled open to establish the AP model, and the serum levels of melatonin and pro-inflammatory cytokines, including interleukin 1β (IL-1β), interleukin 18 (IL-18) and tumor necrosis factor α (TNF-α), were assessed at 1, 3 and 5 d post injury. At the same time points, the expression of TLR4 signaling in the pulp was explored by quantitative real-time PCR and immunohistochemistry. The AP rats were administered an abdominal injection of melatonin to assess whether melatonin rescued AP and TLR4/NF-ĸB signaling. Dental pulp injury led to an approximately five-day period acute pulp inflammation and necrosis in the pulp and a significant up-regulation of IL-1β, IL-18 and TNF-α in the serum. ELISA results showed that the level of melatonin in the serum decreased due to AP, while an abdominal injection of melatonin suppressed the increase in serum cytokines and the percentage of necrosis at the 5 d of the injured pulp. Consistent with the inflammation in AP rats, TLR4, NF-ĸB, TNF-α and IL-1β in the pulp were increased post AP compared with the baseline expression. And melatonin showed an inhibition on TLR4/NF-ĸB signaling as well as IL-1β and TNF-α production in the pulp of AP rats. Furthermore, melatonin could also regulate the expression of TLR4/NF-ĸB signaling in LPS-stimulated HDPCs. These data suggested that dental pulp injury induced AP and reduced the serum level of melatonin and that supplementation with melatonin may have a protective effect on AP by modulating TLR4/NF-ĸB signaling in the pulp and in pulp cells. PMID:25755829

A monoclonal antibody recognizes undifferentiation-specific carbohydrate moieties expressed on cell surface of the human dental pulp cells.

PubMed

Kang, Kyung-Jung; Ko, Seon-Yle; Ryu, Chun-Jeih; Jang, Young-Joo

2017-05-01

Human dental pulp cells are obtained from dental pulp tissue, and have the ability to form dentin and a pulp-like complex. Although adult stem cells have been identified from the primary culture by using specific cell surface markers, the identity of surface markers for the purification of stem cells within the dental pulp population are still unclear. Previously, we had constructed monoclonal antibodies against the undifferentiated cell-specific surface markers of human dental pulp cells (hDPCs) by performing decoy immunization. Among them, a monoclonal antibody against the cell surface antigen of the undifferentiated hDPCs (named UPSA-1) was purified and its heavy and light chain consensus regions were analyzed. The cell surface binding affinity of UPSA-1 mAb on the undifferentiated hDPCs was stronger than that on the differentiated cells. When tunicamycin was applied to hDPSCs during culture, the cell surface binding affinity of the antibody was dramatically decreased, and dentinogenic differentiation was reduced. The purified UPSA-1 antigen band resulting from immunoprecipitation disappeared or shifted down on the SDS-PAGE by deglycosylation. These data suggested that glycosylation on the cell surface might be a marker of an undifferentiated state, and that UPSA-1 mAb might be useful for identifying the carbohydrate moiety on the cell surface of undifferentiated pulp cells. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Oxygen saturation in the dental pulp of permanent teeth: a critical review.

PubMed

Bruno, Kely Firmino; Barletta, Fernando Branco; Felippe, Wilson Tadeu; Silva, Júlio Almeida; Gonçalves de Alencar, Ana Helena; Estrela, Carlos

2014-08-01

Pulse oximetry is a noninvasive method for assessing vascular health based on oxygen saturation level. The method has recently also been used to assess dental pulp vitality, but a median oxygen saturation level suggestive of normal pulp physiology has not been determined. The objective of this study was to make a critical analysis of the published research to establish the median oxygen saturation for the diagnosis of normal dental pulps in maxillary anterior permanent teeth using pulse oximetry. Studies reporting on the use of pulse oximeters to determine oxygen saturation in dental pulps were retrieved using the MEDLINE, Scientific Electronic Library Online, and Cochrane Central Register of Controlled Trials databases plus a manual search of relevant references cited by selected articles. Different combinations of the terms "oximetry," "oximeter," "pulp," "dental," and "dentistry" were used in the search. Statistical analysis was performed for each group of teeth (central incisors, lateral incisors, and canines) using R statistical software (US EPA ORD NHEERL, Corvallis, OR) and a random effects model (P < .0001) with an I(2) of 99%. Of the 295 articles found, only 6 met the inclusion criteria (472 teeth). Of these, the number of articles included in each analysis (according to tooth group) was as follows: all 6 studies (288 teeth) for central incisors at a median oxygen saturation of 87.73%, 3 studies (90 teeth) for lateral incisors at a median oxygen saturation of 87.24%, and 4 studies (94 teeth) for canines at a median oxygen saturation of 87.26%. The median oxygen saturation in normal dental pulps of permanent central incisors, lateral incisors, and canines was higher than 87%. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Pulpal reaction to a dental adhesive in deep human cavities.

PubMed

Torstenson, B

1995-08-01

In the last years several dental adhesives have been developed. They are supposed to chemically adhere to dentin and a liner to protect the pulp is not used. The aim of this study was to compare the short-term pulpal reaction, in an intra-toothpair study, between a dental adhesive, Scotchbond 2, and a lining system, Tubulitec, in combination with P-50 in surface-sealed cavities. Deep buccal cavities in 16 human pairs of premolars, 32 teeth, were restored in vivo with a light cured composite resin, P-50. To minimize bacterial contamination all cavities were treated with a cleanser, Tubulicid, and the cavities were surface-sealed with temporary cement, Coltosol. One tooth in each pair, the test, was treated with Scotchprep Dentin Primer and Scotchbond 2 Light Cure Dental Adhesive. In the other tooth in the pair, the control, Tubulitec Primer and Liner were used. The teeth were extracted after 6-14 days. The sections were evaluated for degree of inflammation and the presence of bacteria. Irrespective of treatment of dentin the majority of teeth, 23, including one pulpal exposure, revealed no inflammation or a few inflammatory cells. In four test teeth, including one pulpal exposure, and two controls, growth of bacteria was found on the cavity walls and slight or moderate inflammation was seen in the corresponding pulps. In one test and two control teeth slight inflammation was seen but no bacteria could be detected. In the absence of bacteria Scotchbond 2 did not seem to irritate the pulp.(ABSTRACT TRUNCATED AT 250 WORDS)

Success of Maxillary Alveolar Defect Repair in Rats Using Osteoblast-Differentiated Human Deciduous Dental Pulp Stem Cells.

PubMed

Jahanbin, Arezoo; Rashed, Roozbeh; Alamdari, Daryoush Hamidi; Koohestanian, Niloufar; Ezzati, Atefeh; Kazemian, Mojgan; Saghafi, Shadi; Raisolsadat, Mohammad Ali

2016-04-01

The use of cell-based therapies represents one of the most advanced methods for enhancing the regenerative response in craniofacial abnormalities. The main aim of this study was to evaluate the regenerative potential of human dental pulp stem cells, isolated from deciduous teeth, for reconstructing maxillary alveolar defects in Wistar rats. Human deciduous dental pulp stem cells were isolated and stimulated to differentiate into osteoblasts in culture media. Maxillary alveolar defects were created in 60 Wistar rats by a surgical procedure. Then, on the basis of the type of graft used to repair the bone defect, the rats were divided into 6 equal groups: groups 1 and 2, transplantation of iliac bone graft; groups 3 and 4, transplantation of stem cells derived from deciduous dental pulp in addition to collagen matrix; groups 5 and 6, transplantation of just collagen matrix. Then, fetal bone formation, granulation tissue, fibrous tissue, and inflammatory tissue were evaluated by hematoxylin-eosin staining at 1 month (groups 1, 3, and 5) and 2 months (groups 2, 4, and 6) after surgery, and data were analyzed and compared using the Fisher exact test. Maximum fetal bone formation occurred in group 2, in which iliac bone graft was inserted into the defect area for 2 months; there also were significant differences among the groups for bone formation (P = .009). In the 1-month groups, there were no significant differences between the control and stem cell-plus-scaffold groups. There were significant differences between the 2-month groups for fetal bone formation only between the control and scaffold groups (P = .026). The study showed that human dental pulp stem cells are an additional cell resource for repairing maxillary alveolar defects in rats and constitute a promising model for reconstruction of human maxillary alveolar defects in patients with cleft lip and palate. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Thermal Scanning of Dental Pulp Chamber by Thermocouple System and Infrared Camera during Photo Curing of Resin Composites.

PubMed

Hamze, Faeze; Ganjalikhan Nasab, Seyed Abdolreza; Eskandarizadeh, Ali; Shahravan, Arash; Akhavan Fard, Fatemeh; Sinaee, Neda

2018-01-01

Due to thermal hazard during composite restorations, this study was designed to scan the pulp temperature by thermocouple and infrared camera during photo polymerizing different composites. A mesio-occlso-distal (MOD) cavity was prepared in an extracted tooth and the K-type thermocouple was fixed in its pulp chamber. Subsequently, 1 mm increment of each composites were inserted (four composite types were incorporated) and photo polymerized employing either LED or QTH systems for 60 sec while the temperature was recorded with 10 sec intervals. Ultimately, the same tooth was hemisected bucco-lingually and the amalgam was removed. The same composite curing procedure was repeated while the thermogram was recorded using an infrared camera. Thereafter, the data was analyzed by repeated measured ANOVA followed by Tukey's HSD Post Hoc test for multiple comparisons ( α =0.05). The pulp temperature was significantly increased (repeated measures) during photo polymerization ( P =0.000) while there was no significant difference among the results recorded by thermocouple comparing to infrared camera ( P >0.05). Moreover, different composite materials and LCUs lead to similar outcomes ( P >0.05). Although various composites have significant different chemical compositions, they lead to similar pulp thermal changes. Moreover, both the infrared camera and the thermocouple would record parallel results of dental pulp temperature.

The effectiveness of low-intensity red laser for activating a bleaching gel and its effect in temperature of the bleaching gel and the dental pulp.

PubMed

Pleffken, Patrícia Rondon; Borges, Alessandra Bühler; Gonçalves, Sérgio Eduardo D E Paiva; Rocha Gomes Torres, Carlos

2012-04-01

The effectiveness of low-intensity red laser for activating a bleaching gel and its effect in pulp temperature was not investigated in dental literature. The objective of this study was to assess the effectiveness of low-intensity red laser for activating a bleaching gel, as well as its effect in temperature of the bleaching gel and the dental pulp. Forty extracted bovine teeth were immersed in a solution of coffee 14 days for darkening. The initial colors were recorded by spectrophotometric analysis. The specimens were randomly distributed into two groups (N = 20): the control, which did not receive light and the experimental group that received light from an appliance fitted with three red light-emitting laser diodes (λ = 660 nm). A green-colored, 35% H(2) O(2) -based bleaching gel was applied for 30 minutes, and changed three times. After bleaching, the colors were again measured to obtain the L*a*b* values. Color variation was calculated (ΔE) and the data submitted to the non-paired t-test (5%). To assess temperature, 10 human incisors were prepared, in which one thermocouple was placed on the bleaching gel applied on the surface of the teeth and another inside the pulp chamber. There was a significant difference between the groups (p = 0.016), and the experimental group presented a significantly higher mean variation (7.21 ± 2.76) in comparison with the control group (5.37 ± 1.76). There was an increase in pulp temperature, but it was not sufficient to cause damage to the pulp. Bleaching gel activation with low-intensity red laser was capable of increasing the effectiveness of bleaching treatment and did not increase pulp temperature to levels deleterious to the pulp. © 2011 Wiley Periodicals, Inc.

An ultrastructural study on indirect injury of dental pulp caused by high-speed missile projectile to mandible in dogs.

PubMed

Ren, Changqun; Liu, Ruifeng; Tian, Lei; Chen, Peng; Zhou, Shuxia

2008-12-01

The aim of this study was to evaluate the characteristics of indirect injury of dental pulp caused by high-speed missile projectile to mandible in dogs. Eighteen dogs aged 12-13 months were divided equally into six groups (n = 3 in each group) with random allocation, then a high-speed missile projectile (a ball bearing of stainless steel, phi6.0 mm, 0.88 g) was shot at right mandible body (the wound tract was below the fourth premolar, 1 cm or so to the root tips) of each dog, but the teeth were not wounded directly. The dogs were killed 6 h (n = 3), 24 h (n = 3), 3 days (n = 3), 7 days (n = 3), 2 weeks (n = 3) and 4 weeks (n = 3) after the wound, respectively; then ultrastructural change of dental pulp of the fourth premolar and the second premolar of right mandible, and the second premolar of left mandible was observed through transmission electron microscope. The results showed that mean initial velocity of projectiles was 778.0 +/- 33.2 m s(-1) and mean projection energy was 266.1 +/- 19.1 J, which were in conformity with parameters of gunshot wound. On the wound side, dental pulp of the fourth mandibular premolar was injured seriously and irreversible necrosis happened in the end; yet, dental pulp of the second mandibular premolar was injured less seriously, reversibly; on the opposite side, dental pulp of the second mandibular premolar was injured slightly and temporarily. It may be concluded that there are several characteristics in indirect injury of dental pulp caused by high-speed missile projectile to dogs' mandible: the injured area is relatively extensive; traumatic degree decreases progressively and sharply with the distance to the wound tract increasing; ultrastructural change of nerval damage takes place in early stage after wound, etc.

Evaluation of dental pulp sensibility tests in a clinical setting.

PubMed

Jespersen, James J; Hellstein, John; Williamson, Anne; Johnson, William T; Qian, Fang

2014-03-01

The goal of this project was to evaluate the performance of dental pulp sensibility testing with Endo Ice (1,1,1,2-tetrafluoroethane) and an electric pulp tester (EPT) and to determine the effect of several variables on the reliability of these tests. Data were collected from 656 patients seen in the University of Iowa College of Dentistry Endodontic graduate clinic. The results of pulpal sensibility tests, along with the tooth number, age, sex, number of restored surfaces, presence or absence of clinical or radiographic caries, and reported recent use of analgesic medications, were recorded. The presence of vital tissue within the pulp chamber was used to verify the diagnosis. The Endo Ice results showed accuracy, 0.904; sensitivity, 0.916; specificity, 0.896; positive predictive value, 0.862; and negative predictive value, 0.937. The EPT results showed accuracy, 0.75; sensitivity, 0.84; specificity, 0.74; positive predictive value, 0.58; and negative predictive value, 0.90. Patients aged 21-50 years exhibited a more accurate response to cold testing (P = .0043). Vital teeth with caries responded more accurately to cold testing (P = .0077). There was no statistically significant difference noted with any other variable examined. Pulpal sensibility testing with Endo Ice and EPT are accurate and reliable methods of determining pulpal vitality. Patients aged 21-50 exhibited a more accurate response to cold. Sex, tooth type, number of restored surfaces, presence of caries, and recent analgesic use did not significantly alter the results of pulpal sensibility testing in this study. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Effect of biomaterials on angiogenesis during vital pulp therapy

PubMed Central

SAGHIRI, Mohammad Ali; ASATOURIAN, Armen; GARCIA-GODOY, Franklin; SHEIBANI, Nader

2016-01-01

This review intended to provide an overview of the effects of dental materials, used in dentin-pulp complex and dental pulp regeneration, on angiogenesis processes during regenerative endodontic procedures. An electronic search was performed in PubMed and MEDLINE databases via OVID using the keywords mentioned in the PubMed and MeSH headings for English language published articles from January 2005–April 2014 that evaluated the angiogenic properties of different dental materials used in regenerative endodontic procedures. Of the articles identified in an initial search, only 40 articles met the inclusion criteria set for this review. Vital pulp therapy materials might have positive effects on angiogenesis events, while most of the canal irrigating solutions and antibiotic pastes have anti-angiogenic activity except for EDTA. Future clinical studies will be helpful in defining the mechanisms of action for dental materials that promote or inhibit angiogenesis events at applied areas. PMID:27546854

CYTOTOXICITY AND BIOCOMPATIBILITY OF DIRECT AND INDIRECT PULP CAPPING MATERIALS

PubMed Central

Modena, Karin Cristina da Silva; Casas-Apayco, Leslie Caroll; Atta, Maria Teresa; Costa, Carlos Alberto de Souza; Hebling, Josimeri; Sipert, Carla Renata; Navarro, Maria Fidela de Lima; Santos, Carlos Ferreira

2009-01-01

There are several studies about the cytotoxic effects of dental materials in contact with the pulp tissue, such as calcium hydroxide (CH), adhesive systems, resin composite and glass ionomer cements. The aim of this review article was to summarize and discuss the cytotoxicity and biocompatibility of materials used for protection of the dentin-pulp complex, some components of resin composites and adhesive systems when placed in direct or indirect contact with the pulp tissue. A large number of dental materials present cytotoxic effects when applied close or directly to the pulp, and the only material that seems to stimulate early pulp repair and dentin hard tissue barrier formation is CH. PMID:20027424

Influence of different types of light on the response of the pulp tissue in dental bleaching: a systematic review.

PubMed

Benetti, Francine; Lemos, Cleidiel Aparecido Araújo; de Oliveira Gallinari, Marjorie; Terayama, Amanda Miyuki; Briso, André Luiz Fraga; de Castilho Jacinto, Rogério; Sivieri-Araújo, Gustavo; Cintra, Luciano Tavares Angelo

2018-05-01

This systematic review (PROSPERO register: CRD42016053140) investigated the influence of different types of light on the pulp tissue during dental bleaching. Two independent authors conducted a systematic search and risk of bias evaluations. An electronic search was undertaken (PubMed/Medline, Embase, The Cochrane Library, and other databases) until May 2017. The population, intervention, comparison, outcomes (PICO) question was: "Does the light in dental bleaching change the response of the pulp to the bleaching procedure?" The intervention involved pulp tissue/cells after bleaching with light, while the comparison involved pulp tissue/cells after bleaching without light. The primary outcome was the inflammation/cytotoxicity observed in pulp after bleaching. Out of 2210 articles found, 12 articles were included in the review; four were in vivo studies (one study in dogs/others in human), and eight were in vitro studies (cell culture/with artificial pulp chamber or not). The light source used was halogen, light-emitting diode (LED), and laser. Only one in vivo study that used heat to simulate light effects showed significant pulp inflammation. Only two in vitro studies demonstrated that light influenced cell metabolism; one using halogen light indicated negative effects, and the other using laser therapy indicated positive effects. Given that animal and in vitro studies have been identified, there remain some limitations for extrapolation to the human situation. Furthermore, different light parameters were used. The effects of dental bleaching on the pulp are not influenced by different types of light, but different light parameters can influence these properties. There is insufficient evidence about the influence of different types of light on inflammation/cytotoxicity of the pulp.

Manufacturing of dental pulp cell-based products from human third molars: current strategies and future investigations

PubMed Central

Ducret, Maxime; Fabre, Hugo; Degoul, Olivier; Atzeni, Gianluigi; McGuckin, Colin; Forraz, Nico; Alliot-Licht, Brigitte; Mallein-Gerin, Frédéric; Perrier-Groult, Emeline; Farges, Jean-Christophe

2015-01-01

In recent years, mesenchymal cell-based products have been developed to improve surgical therapies aimed at repairing human tissues. In this context, the tooth has recently emerged as a valuable source of stem/progenitor cells for regenerating orofacial tissues, with easy access to pulp tissue and high differentiation potential of dental pulp mesenchymal cells. International guidelines now recommend the use of standardized procedures for cell isolation, storage and expansion in culture to ensure optimal reproducibility, efficacy and safety when cells are used for clinical application. However, most dental pulp cell-based medicinal products manufacturing procedures may not be fully satisfactory since they could alter the cells biological properties and the quality of derived products. Cell isolation, enrichment and cryopreservation procedures combined to long-term expansion in culture media containing xeno- and allogeneic components are known to affect cell phenotype, viability, proliferation and differentiation capacities. This article focuses on current manufacturing strategies of dental pulp cell-based medicinal products and proposes a new protocol to improve efficiency, reproducibility and safety of these strategies. PMID:26300779

Efficacy of Sex Determination from Human Dental Pulp Tissue and its Reliability as a Tool in Forensic Dentistry.

PubMed

Khanna, Kaveri Surya

2015-01-01

Sex determination is one of the primary steps in forensics. Barr body can be used as a histological method for identification of sex as it is found to be specific to female somatic cells and rare in male cells. To demarcate human dental pulp as an important identification tool of sex in forensic odontology (FO) and to evaluate the time period till which sex can be determined from pulp tissue using three stains H and E, Feulgen, and acridine - orange under fluorescence so as. 90 pulp samples (45 males and 45 females) were subjected to Barr body analysis for determination of sex using light and fluorescent microscopy. Barr body was found to be positive for female samples and negative or rare in the male sample (<3%). Barr body from human dental pulp tissue can be used as a successful determinant of sex identification in FO.

Comparison of the effects of cognitive behavioural therapy and inhalation sedation on child dental anxiety.

PubMed

Kebriaee, F; Sarraf Shirazi, A; Fani, K; Moharreri, F; Soltanifar, A; Khaksar, Y; Mazhari, F

2015-04-01

To compare the effectiveness of inhalation sedation with nitrous oxide/oxygen (N2O/O2) and cognitive behavioural therapy (CBT) in reducing dental anxiety in preschool children. Randomised controlled clinical trial. This study was conducted on 45 preschoolers with moderate to severe dental anxiety (determined by the Children's Fear Survey Schedule Dental Subscale), who required pulp treatment of at least one primary mandibular molar. Baseline anxiety and cooperation levels were determined using Venham Clinical Anxiety and Cooperation Scales (VCAS and VCCS) and Venham Picture Test (VPT) at the first dental visit (dental prophylaxis and fluoride treatment). Before the second dental visit (pulp treatment), the children were randomly assigned to one of three groups--1: control, 2: N(2)O/O(2) and 3: CBT. In group 1, the usual behaviour management techniques were used, in group 2, nitrous oxide/oxygen gas was used and in group 3, unrelated play, Benson's breathing and positive self-talk and modelling were used. Anxiety and cooperation levels were determined at three periods: injection, rubber dam placement and the application of a high-speed handpiece with VCAS and VCCS and VPT. Finally, anxiety and cooperation differences between the two dental visits were compared within the three groups. Chi square, ANOVA and Kruskal-Wallis and Mann-Whitney U tests were used. N(2)O/O(2) and CBT significantly resulted in lower anxiety and higher cooperation in the second visit (at all three periods) compared to the control, although there was no significant difference between these two treatment methods. Both test methods were effective in reducing dental anxiety in preschoolers. Considering the adverse effects and necessity of equipment and trained personnel when using nitrous oxide and oxygen inhalation sedation, cognitive behavioural therapy is preferable because of its better applicability.

Molecular and clinical analyses of Helicobacter pylori colonization in inflamed dental pulp.

PubMed

Nomura, Ryota; Ogaya, Yuko; Matayoshi, Saaya; Morita, Yumiko; Nakano, Kazuhiko

2018-04-16

Recently, dental pulp has been considered a possible source of infection of Helicobacter pylori (H. pylori) in children. We previously developed a novel PCR system for H. pylori detection with high specificity and sensitivity using primer sets constructed based on the complete genome information for 48 H. pylori strains. This PCR system showed high sensitivity with a detection limit of 1-10 cells when serial dilutions of H. pylori genomic DNA were used as templates. However, the detection limit was lower (10 2 -10 3 cells) when H. pylori bacterial DNA was detected from inflamed pulp specimens. Thus, we further refined the system using a nested PCR method, which was much more sensitive than the previous single PCR method. In addition, we examined the distribution and virulence of H. pylori in inflamed pulp tissue. Nested PCR system was constructed using primer sets designed from the complete genome information of 48 H. pylori strains. The detection limit of the nested PCR system was 1-10 cells using both H. pylori genomic DNA and bacterial DNA isolated from inflamed pulp specimens. Next, distribution of H. pylori was examined using 131 inflamed pulp specimens with the nested PCR system. In addition, association between the detection of H. pylori and clinical information regarding endodontic-infected teeth were investigated. Furthermore, adhesion property of H. pylori strains to human dental fibroblast cells was examined. H. pylori was present in 38.9% of inflamed pulp specimens using the nested PCR system. H. pylori was shown to be predominantly detected in primary teeth rather than permanent teeth. In addition, samplings of the inflamed pulp were performed twice from the same teeth at 1- or 2-week intervals, which revealed that H. pylori was detected in most specimens in both samplings. Furthermore, H. pylori strains showed adhesion property to human dental fibroblast cells. Our results suggest that H. pylori colonizes inflamed pulp in approximately 40% of all cases through adhesion to human dental fibroblast cells.

Evaluation of age-related changes with cross-sectional CT imaging of teeth

NASA Astrophysics Data System (ADS)

Fukui, Tatsumasa; Kita, Kanade; Kamemoto, Hiromasa; Nishiyama, Wataru; Yoshida, Hiroyasu; Iida, Yukihiro; Katsumata, Akitoshi; Muramatsu, Chisako; Fujita, Hiroshi

2017-03-01

Tooth pulp atrophy occurs with increasing age. An age estimation procedure using dental cone beam computed tomography (CBCT) imaging was developed. Clinical dental CBCT images of 60 patients (aged from 20 to 80 years) were evaluated. The ratio of the cross-sectional area of the pulp cavity to the cross-sectional area of the tooth (pulp cavity ratio) was calculated. The pulp cavity ratio in the labio-lingual plane of the mandibular anterior teeth and the mesio-distal plane of the maxillary anterior teeth was strongly correlated with the patients' age. The pulp cavity ratio of anterior teeth may be a useful parameter for estimating age.

Altered transcription of inflammation-related genes in dental pulp of coeliac children.

PubMed

Bossù, Maurizio; Montuori, Monica; Casani, Daniela; Di Giorgio, Gianni; Pacifici, Andrea; Ladniak, Barbara; Polimeni, Antonella

2016-09-01

Coeliac disease is a chronic small intestinal immune-mediated enteropathy precipitated by exposure to dietary gluten, and possible relationships between coeliac disease and dental pathogenic conditions during childhood have been poorly investigated. The dental pulp plays a pivotal role in the immune defence against possible entry of pathogens from teeth, and the aim of this work was to investigate quantitative transcription levels of selected genes (IL-9, IL-11, IL-15, IL-18, IL-21, IL-27, MICA, IFN-γ) coding for pro-inflammatory immune innate activities in the pulp of primary teeth from healthy children and children with coeliac disease. The pulp from primary teeth of 10 healthy children and 10 children with coeliac disease was used to extract RNA and prepare cDNA for quantitative PCR transcription analysis employing commercial nucleotide probes for selected genes. In children with coeliac disease, the genes coding for pro-inflammatory cytokines IFN-γ, IL-11, IL-18, and IL-21 were significantly overexpressed, suggesting the possible importance of these cytokines in the relationships between coeliac disease and dental disorders. For the first time, we reported in dental pulp of children possible relationships between coeliac disease and modulation in transcription of cytokine-dependent inflammatory activities. © 2015 BSPD, IAPD and John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

[Temperature-dependent changes in the microcirculation of the dental pulp].

PubMed

Raab, W H; Müller, H

1989-07-01

Laser Doppler flowmetry was used to study the changes in the blood flow within the dental pulp as a reaction to thermal stimuli between 17 degrees C and 57 degree C. Temperatures below 31 degrees C resulted in a reduction, temperatures above 43 degrees C in an increase in blood flow. Temperatures higher than 49 degrees C caused irreversible damage to the pulp's microcirculation. Experimental nerve blocks showed that the reactive increase is linked to the afferent rather than the sympathetic innervation of the tooth pulp.

Mesenchymal and embryonic characteristics of stem cells obtained from mouse dental pulp.

PubMed

Guimarães, Elisalva Teixeira; Cruz, Gabriela Silva; de Jesus, Alan Araújo; Lacerda de Carvalho, Acácia Fernandes; Rogatto, Silvia Regina; Pereira, Lygia da Veiga; Ribeiro-dos-Santos, Ricardo; Soares, Milena Botelho Pereira

2011-11-01

Several studies have demonstrated that human dental pulp is a source of mesenchymal stem cells. To better understand the biological properties of these cells we isolated and characterized stem cells from the dental pulp of EGFP transgenic mice. The pulp tissue was gently separated from the roots of teeth extracted from C57BL/6 mice, and cultured under appropriate conditions. Flow cytometry, RT-PCR, light microscopy (staining for alkaline phosphatase) and immunofluorescence were used to investigate the expression of stem cell markers. The presence of chromosomal abnormalities was evaluated by G banding. The mouse dental pulp stem cells (mDPSC) were highly proliferative, plastic-adherent, and exhibited a polymorphic morphology predominantly with stellate or fusiform shapes. The presence of cell clusters was observed in cultures of mDPSC. Some cells were positive for alkaline phosphatase. The karyotype was normal until the 5th passage. The Pou5f1/Oct-4 and ZFP42/Rex-1, but not Nanog transcripts were detected in mDPSC. Flow cytometry and fluorescence analyses revealed the presence of a heterogeneous population positive for embryonic and mesenchymal cell markers. Adipogenic, chondrogenic and osteogenic differentiation was achieved after two weeks of cell culture under chemically defined in vitro conditions. In addition, some elongated cells spontaneously acquired a contraction capacity. Our results reinforce that the dental pulp is an important source of adult stem cells and encourage studies on therapeutic potential of mDPSC in experimental disease models. Copyright © 2011 Elsevier Ltd. All rights reserved.

Cytotoxicity Evaluation of Self Adhesive Composite Resin Cements by Dentin Barrier Test on 3D Pulp Cells.

PubMed

Ulker, Hayriye Esra; Sengun, Abdulkadir

2009-04-01

The aim of this study was to evaluate the effects of five self-etch dental composite resin cements on the cell viability of bovine dental papilla-derived cells. The cytotoxicity of composite resin cements (Rely X Unicem Clicker, 3M ESPE; MaxCem; KERR, Panavia F 2.0; Kuraray, BisCem; Bisco and Bistite II DC; Tokuyama) was analyzed in a dentin barrier test device using three-dimensional (3D) pulp cell cultures. A commercially available cell culture perfusion chamber was separated into two compartments by 500 mum dentin disc. The three dimensional cultures placed on a dentin disk held in place by a special biocompatible stainless-steel holder. Test materials were introduced into the upper compartment in direct contact with the cavity side of the dentin disks according to the manufacturer's instructions. Subsequently, the pulpal part of the perfusion chamber containing the cell cultures was perfused with medium (2 ml/h). After an exposure period of 24 h, the cell survival was determined by the MTT assay. Statistical analyses were performed using the Mann-Whitney U-test. In dentin barrier test, cell survival was similar with Maxcem and negative control group (P>.05), and all other tested materials were cytotoxic for the three dimensional cell cultures (P>.05). The significance of composite resin cements is being more important in dentistry. The cytotoxic potencies demonstrated by these materials might be of clinical relevance. Some composite resin cements include biologically active ingredients and may modify pulp cell metabolism when the materials are used in deep cavities or directly contact pulp tissue.

Predictive values of thermal and electrical dental pulp tests: a clinical study.

PubMed

Villa-Chávez, Carlos E; Patiño-Marín, Nuria; Loyola-Rodríguez, Juan P; Zavala-Alonso, Norma V; Martínez-Castañón, Gabriel A; Medina-Solís, Carlo E

2013-08-01

For a diagnostic test to be useful, it is necessary to determine the probability that the test will provide the correct diagnosis. Therefore, it is necessary to calculate the predictive value of diagnostics. The aim of the present study was to identify the sensitivity, specificity, positive and negative predictive values, accuracy, and reproducibility of thermal and electrical tests of pulp sensitivity. The thermal tests studied were the 1, 1, 1, 2-tetrafluoroethane (cold) and hot gutta-percha (hot) tests. For the electrical test, the Analytic Technology Pulp Tester (Analytic Technology, Redmond, WA) was used. A total of 110 teeth were tested: 60 teeth with vital pulp and 50 teeth with necrotic pulps (disease prevalence of 45%). The ideal standard was established by direct pulp inspection. The sensitivities of the diagnostic tests were 0.88 for the cold test, 0.86 for the heat test, and 0.76 for the electrical test, and the specificity was 1.0 for all 3 tests. The negative predictive value was 0.90 for the cold test, 0.89 for the heat test, and 0.83 for the electrical test, and the positive predictive value was 1.0 for all 3 tests. The highest accuracy (0.94) and reproducibility (0.88) were observed for the cold test. The cold test was the most accurate method for diagnostic testing. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

[Correlation between dental pulp demyelination degree and pain visual analogue scale scores data under acute and chronic pulpitis].

PubMed

Korsantiia, N B; Davarashvili, X T; Gogiashvili, L E; Mamaladze, M T; Tsagareli, Z G; Melikadze, E B

2013-05-01

The aim of study is the analysis of pulp nerve fibers demyelination degree and its relationship with Visual Analogue Scale (VAS) score that may be measured as objective criteria. Material and methods of study. Step I: electron micrografs of dental pulp simples with special interest of myelin structural changes detected in 3 scores system, obtained from 80 patients, displays in 4 groups: 1) acute and 2) chronic pulpitis without and with accompined systemic deseases, 20 patients in each group. Dental care was realized in Kutaisi N1 Dental clinic. Step II - self-reported VAS used for describing dental pain. All data were performed by SPSS 10,0 version statistics including Spearmen-rank and Mann-Whitny coefficients for examine the validity between pulp demyelination degree and pain intensity in verbal, numbered and box scales. Researched Data were shown that damaged myelin as focal decomposition of membranes and Schwann cells hyperthrophia correspond with acute dental pain intensity as Spearman index reported in VAS numbered Scales, myelin and axoplasm degeneration as part of chronic gangrenous pulpitis disorders are in direct correlation with VAS in verbal, numbered and behavioral Rating Scales. In fact, all morphological and subjective data, including psychomotoric assessment of dental painin pulpitis may be used in dental practice for evaluation of pain syndrome considered personal story.

Effect of Propolis on Dentin Regeneration and the Potential Role of Dental Pulp Stem Cell in Guinea Pigs

PubMed Central

Ahangari, Zohreh; Naseri, Mandana; Jalili, Maryam; Mansouri, Yasaman; Mashhadiabbas, Fatemeh; Torkaman, Anahita

2012-01-01

Objective: Evaluation of the effect of Propolis as a bioactive material on quality of dentin and presence of dental pulp stem cells. Materials and Methods: For conducting this experimental split-mouth study,a total of 48 maxillary and mandibular incisors of male guinea pigs were randomly divided into an experimental Propolis group and a control calcium hydroxide group. Cutting the crowns and using Propolis or calcium hydroxide to cap the pulp, all of the cavities were sealed. Sections of the teeth were obtained after sacrificing 4 guinea pigs from each group on the 10th, 15th and 30th day. After they had been stained by hematoxylin and eosin (H&E), specimens underwent a histological evaluation under a light microscope for identification of the presence of odontoblast-like cells, pulp vitality, congestion, inflammation of the pulp and the presence of remnants of the material used. The immunohistochemistry (IHC) method using CD29 and CD146 was performed to evaluate the presence of stem cells and the results were statistically evaluated by Kruskal-Wallis, Chi Square and Fisher tests. Results: In H&E stained specimens, there was no difference between the two groups in the presence of odontoblast-like cells, pulp vitality, congestion, inflammation of the pulp and the presence of remnants of used material(p>0.05). There was a significant difference between the quality of regenerative dentin on the 15th and 30th days (p<0.05): all of the Propolis cases presented tubular dentin while 14% of the calcium hydroxide cases produced porous dentin. There was no significant difference between Propolis and calcium hydroxide in stimulation of dental pulp stem cells (DPSCs). Conclusion: This study which is the first one that documented the stimulation of stem cells by Propolis, provides evidence that this material has advantages over calcium hydroxide as a capping agent in vital pulp therapy. In addition to producing no pulpal inflammation, infection or necrosis this material induces the production of high quality tubular dentin. PMID:23508294

Inflammation triggers constitutive activity and agonist-induced negative responses at M(3) muscarinic receptor in dental pulp.

PubMed

Sterin-Borda, Leonor; Orman, Betina; De Couto Pita, Alejandra; Borda, Enri

2011-02-01

The purpose of this study was to investigate whether the inflammation of rat dental pulp induces the muscarinic acetylcholine receptor (mAChR) constitutive receptor activity. Pulpitis was induced with bacterial lipolysaccharide in rat incisors dental pulp. Saturation assay with [(3)H]-quinuclidinyl benzilate ([(3)H] QNB), competitive binding with different mAChR antagonist subtypes, and nitric oxide synthase (NOS) activity were performed. A drastic change in expression and response to mAChR subtypes was observed in pulpitis. Inflamed pulp expressed high number of M(3) mAChR of high affinity, whereas the M(1) mAChR is the main subtype displayed in normal pulp. Consistent with the identification of the affinity constant (Ki) of M(3) and Ki of M(1) in both pulpitis and in normal pulps are the differences in the subtype functionality of these cells. In pulpitis, pilocarpine (1 × 10(-11) mol/L to 5 × 10(-9) mol/L) exerted an inhibitory action on NOS activity that was blocked by J 104129 fumarate (highest selective affinity to M(3) mAChR). In normal pulps, pilocarpine (1 × 10(-11) mol/L to 5 × 10(-9) mol/L) has no effect. NOS basal activity was 5.9 times as high in pulpitis as in the normal pulp as a result of the activation of inducible NOS. The irreversible pulpitis could induce a mAChR alteration, increasing the high-affinity receptor density and transduction-coupling efficiency of inducible NOS activity, leading to a spontaneously active conformation of the receptor. Pilocarpine acting as an inverse agonist might be useful therapeutically to prevent necrosis and subsequent loss of dental pulp. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Classification of Ancient Mammal Individuals Using Dental Pulp MALDI-TOF MS Peptide Profiling

PubMed Central

Tran, Thi-Nguyen-Ny; Aboudharam, Gérard; Gardeisen, Armelle; Davoust, Bernard; Bocquet-Appel, Jean-Pierre; Flaudrops, Christophe; Belghazi, Maya; Raoult, Didier; Drancourt, Michel

2011-01-01

Background The classification of ancient animal corpses at the species level remains a challenging task for forensic scientists and anthropologists. Severe damage and mixed, tiny pieces originating from several skeletons may render morphological classification virtually impossible. Standard approaches are based on sequencing mitochondrial and nuclear targets. Methodology/Principal Findings We present a method that can accurately classify mammalian species using dental pulp and mass spectrometry peptide profiling. Our work was organized into three successive steps. First, after extracting proteins from the dental pulp collected from 37 modern individuals representing 13 mammalian species, trypsin-digested peptides were used for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis. The resulting peptide profiles accurately classified every individual at the species level in agreement with parallel cytochrome b gene sequencing gold standard. Second, using a 279–modern spectrum database, we blindly classified 33 of 37 teeth collected in 37 modern individuals (89.1%). Third, we classified 10 of 18 teeth (56%) collected in 15 ancient individuals representing five mammal species including human, from five burial sites dating back 8,500 years. Further comparison with an upgraded database comprising ancient specimen profiles yielded 100% classification in ancient teeth. Peptide sequencing yield 4 and 16 different non-keratin proteins including collagen (alpha-1 type I and alpha-2 type I) in human ancient and modern dental pulp, respectively. Conclusions/Significance Mass spectrometry peptide profiling of the dental pulp is a new approach that can be added to the arsenal of species classification tools for forensics and anthropology as a complementary method to DNA sequencing. The dental pulp is a new source for collagen and other proteins for the species classification of modern and ancient mammal individuals. PMID:21364886

EZH2 regulates dental pulp inflammation by direct effect on inflammatory factors.

PubMed

Hui, Tianqian; A, Peng; Zhao, Yuan; Yang, Jing; Ye, Ling; Wang, Chenglin

2018-01-01

Pulpitis is a multi-factorial disease that could be caused by complex interactions between genetics, epigenetics and environmental factors. We aimed to evaluate the role of Enhancer of Zeste Homolog 2 (EZH2) in the inflammatory response of human dental pulp cells (HDPCs) and dental pulp tissues. The expressions of inflammatory cytokines in HDPCs treated by EZH2 complex or EZH2 siRNA with or without rhTNF-α were examined by quantitative real-time polymerase chain reaction (q-PCR). The levels of secreted inflammatory cytokines including IL-6, IL-8, IL-15, CCL2 and CXCL12 in culture supernatants were measured by Luminex assay. In rat pulpitis model, the effects of EZH2 on dental pulp tissues were verified by histology. We invested the mechanisms of the effect of EZH2 on the inflammatory factors by ChIP assay. EZH2 down-regulation inhibited the expression of inflammatory factors, including IL-6, IL-8, IL-15, CCL2 and CXCL12 in HDPCs. EZH2 complex promoted the expression and secretion of these inflammatory factors in HDPCs, while EZH2 silencing could attenuate the promotion of inflammatory factors that were induced by rhTNF-α. In pulpitis models of rats, EZH2 down-regulation inhibited the inflammatory process of dental pulp while EZH2 complex showed no significant facilitation of pulpal inflammation. In addition, EZH2 could bind on the promoters of IL-6, IL-8 and CCL2, but not IL-15 and CXCL12, to affect the transcription of these proinflammatory cytokines. In HDPCs, EZH2 could induce inflammation, while EZH2 down-regulation could attenuate the inflammatory responses. EZH2 plays an important role in this inflammatory process of dental pulp. Copyright © 2017 Elsevier Ltd. All rights reserved.

Inhibition of TGF-β Signaling in SHED Enhances Endothelial Differentiation.

PubMed

Xu, J G; Gong, T; Wang, Y Y; Zou, T; Heng, B C; Yang, Y Q; Zhang, C F

2018-02-01

Low efficiency of deriving endothelial cells (ECs) from adult stem cells hampers their utilization in tissue engineering studies. The purpose of this study was to investigate whether suppression of transforming growth factor beta (TGF-β) signaling could enhance the differentiation efficiency of dental pulp-derived stem cells into ECs. We initially used vascular endothelial growth factor A (VEGF-A) to stimulate 2 dental pulp-derived stem cells (dental pulp stem cells and stem cells from human exfoliated deciduous teeth [SHED]) and compared their differentiation capacity into ECs. We further evaluated whether the vascular endothelial growth factor receptor I (VEGF-RI)-specific ligand placental growth factor-1 (PlGF-1) could mediate endothelial differentiation. Finally, we investigated whether the TGF-β signaling inhibitor SB-431542 could enhance the inductive effect of VEGF-A on endothelial differentiation, as well as the underlying mechanisms involved. ECs differentiated from dental pulp-derived stem cells exhibited the typical phenotypes of primary ECs, with SHED possessing a higher endothelial differentiation potential than dental pulp stem cells. VEGFR1-specific ligand-PLGF exerted a negligible effect on SHED-ECs differentiation. Compared with VEGF-A alone, the combination of VEGF-A and SB-431542 significantly enhanced the endothelial differentiation of SHED. The presence of SB-431542 inhibited the phosphorylation of Suppressor of Mothers Against Decapentaplegic 2/3 (SMAD2/3), allowing for VEGF-A-dependent phosphorylation and upregulation of VEGFR2. Our results indicate that the combination of VEGF-A and SB-431542 could enhance the differentiation of dental pulp-derived stem cells into endothelial cells, and this process is mediated through enhancement of VEGF-A-VEGFR2 signaling and concomitant inhibition of TGF-β-SMAD2/3 signaling.

Advanced glycation end products increase expression of S100A8 and A9 via RAGE-MAPK in rat dental pulp cells.

PubMed

Nakajima, Y; Inagaki, Y; Kido, J; Nagata, T

2015-04-01

Advanced glycation end products (AGE) are involved in the progression of diabetic complications. Although our previous reports show that AGE increased dental pulp calcification, AGE accumulation is also associated with inflammation. This study examined AGE effect on the expression of inflammation factors using rat dental pulp tissues and cell cultures. Receptor for AGE (RAGE), S100A8, S100A9, and interleukin (IL)-1β were selected as inflammation parameters. Rat dental pulp cells were cultured and treated with AGE, and the effects were determined by real-time PCR. An anti-RAGE antibody or MAPK pathway inhibitors (PD98059, SB203580, and SP60012) were used to investigate AGE signaling pathway. The mRNA levels of RAGE, S100A8, S100A9, and IL-1β were higher in diabetic pulp tissues. AGE increased mRNA expressions of S100A8, S100A9, and IL-1β in cultured dental pulp cells. In the presence of anti-RAGE antibody, AGE did not increase in S100A8 or S100A9 expressions. The AGE-induced increases in S100A8 and S100A9 were inhibited by PD98059 and SB203580, respectively. Advanced glycation end products increased mRNA expression of S100A8, S100A9, and IL-1β under diabetic pulp conditions, and AGE-induced increases in S100A8 and S100A9 expressions may be associated with the RAGE-MAPK signaling pathway. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Tissue Engineering of Necrotic Dental Pulp of Immature Teeth with Apical Periodontitis in Dogs: Radiographic and Histological Evaluation.

PubMed

El Ashiry, Eman A; Alamoudi, Najlaa M; El Ashiry, Mahmoud K; Bastawy, Hagar A; El Derwi, Douaa A; Atta, Hazem M

2018-05-15

To evaluate tissue engineering technology to regenerate pulp-dentin like tissues in pulp canals of immature necrotic permanent teeth with apical periodontitis in dogs. The study was performed on 36 teeth in 12 dogs. The experiment was carried out using split mouth design. In each dog 3 teeth were selected for implementing the study procedure. Apical periodontitis was induced in Group A and B teeth. Group (A): immature upper left 2 nd permanent incisors that were transplanted with a construct of autologous dental pulp stem cells with growth factors seeded in a chitosn hydrogel scaffold. Group (B): immature upper right 2 nd permanent incisor that received only growth factors with scaffold. A third tooth in each dog was selected randomly for isolation of dental pulp stem cells (DPSCs). Both groups were closed with a double coronal seal of white MTA (Mineral trioxide aggregate) and glass ionomer cement. Both groups were monitored radiographically for 4 months and histologically after sacrificing the animals. There was no statistically significant difference in radiographic findings between group (A) and group (B) for healing of radiolucencies, while there was statistically significant difference between group (A) and group (B) regarding radicular thickening, root lengthening and apical closure. Histologically, group (A) teeth showed regeneration of pulp-dentin like tissue while group (B) teeth did not show any tissue regeneration. Dental pulp stem cells and growth factors incorporated in chitosan hydrogel are able to regenerate pulp-dentine like tissue and help in complete root maturation of non-vital immature permanent teeth with apical periodontitis in dogs.

Potential dental pulp revascularization and odonto-/osteogenic capacity of a novel transplant combined with dental pulp stem cells and platelet-rich fibrin.

PubMed

Chen, Yong-Jin; Zhao, Yin-Hua; Zhao, Ya-Juan; Liu, Nan-Xia; Lv, Xin; Li, Qiang; Chen, Fa-Ming; Zhang, Min

2015-08-01

Our aim is to investigate the cytobiological effects of autologous platelet-rich fibrin (PRF) on dental pulp stem cells (DPSCs) and to explore the ectopic and orthotopic possibilities of dental pulp revascularization and pulp-dentin complex regeneration along the root canal cavities of the tooth by using a novel tissue-engineered transplant composed of cell-sheet fragments of DPSCs and PRF granules. Canine DPSCs were isolated and characterized by assaying their colony-forming ability and by determining their cell surface markers and osteogenic/adipogenic differentiation potential. The biological effects of autologous PRF on DPSCs, including cell proliferation, alkaline phosphatase (ALP) activity and odonto-/osteogenic gene expression, were then investigated and quantified. A novel transplant consisting of cell-sheet fragments of DPSCs and PRF granules was adopted to regenerate pulp-dentin-like tissues in the root canal, both subcutaneously in nude mice and in the roots of canines. PRF promoted the proliferation of DPSCs in a dose- and time-dependent manner and induced the differentiation of DPSCs to odonto-/osteoblastic fates by increasing the expression of the Alp, Dspp, Dmp1 and Bsp genes. Transplantation of the DPSC/PRF construct led both to a favorable regeneration of homogeneous and compact pulp-like tissues with abundantly distributed blood capillaries and to the deposition of regenerated dentin along the intracanal walls at 8 weeks post-operation. Thus, the application of DPSC/PRF tissue constructs might serve as a potential therapy in regenerative endodontics for pulp revitalization or revascularization.

DNA methylcytosine dioxygenase ten-eleven translocation 2 enhances lipopolysaccharide-induced cytokine expression in human dental pulp cells by regulating MyD88 hydroxymethylation.

PubMed

Wang, Xinxuan; Feng, Zhihui; Li, Qimeng; Yi, Baicheng; Xu, Qiong

2018-04-13

Dental pulp inflammation is a bacterially driven inflammation process characterized by the local accumulation of cytokines/chemokines that participate in destructive processes in the pulp. Multiple mechanisms are involved in dental pulp inflammation, including epigenetic events, such as DNA methylation/demethylation. Ten-eleven translocation 2 (TET2) is a recently discovered DNA methylcytosine dioxygenase that plays important roles in inflammatory disease. However, its role in the inflammatory response of dental pulp is unknown. We observed elevated mRNA and protein levels of TET2 after lipopolysaccharide (LPS) stimulation in human dental pulp cells (hDPCs). To identify the effects of TET2 on cytokine expression, TET2 was knocked down and cytokines were detected using a cytokine antibody array after LPS stimulation. The protein expression of GM-CSF, IL-6, IL-8 and RANTES decreased in the LPS-induced hDPCs following TET2 knockdown. The downregulated expression levels of IL-6 and IL-8 were further confirmed by real-time quantitative polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA). Additionally, the phosphorylation levels of IKK-α/β, p65 and IκBα of the NF-κB signaling pathway were decreased in the TET2-silenced group. Furthermore, the global 5-hydroxymethylcytosine (5hmC) level was significantly decreased and the genomic 5-methylcytosine (5mC) level was increased in the TET2-deficient hDPCs; TET2 depletion resulted in a decrease in the 5hmC level of the MyD88 promoter following LPS stimulation. These findings indicate that TET2 knockdown inhibits LPS-induced inflammatory response in hDPCs by downregulating MyD88 hydroxymethylation. Thus, TET2-dependent DNA demethylation might play an important role in dental pulp inflammation as an epigenetic regulator.

Thermal Scanning of Dental Pulp Chamber by Thermocouple System and Infrared Camera during Photo Curing of Resin Composites

PubMed Central

Hamze, Faeze; Ganjalikhan Nasab, Seyed Abdolreza; Eskandarizadeh, Ali; Shahravan, Arash; Akhavan Fard, Fatemeh; Sinaee, Neda

2018-01-01

Introduction: Due to thermal hazard during composite restorations, this study was designed to scan the pulp temperature by thermocouple and infrared camera during photo polymerizing different composites. Methods and Materials: A mesio-occlso-distal (MOD) cavity was prepared in an extracted tooth and the K-type thermocouple was fixed in its pulp chamber. Subsequently, 1 mm increment of each composites were inserted (four composite types were incorporated) and photo polymerized employing either LED or QTH systems for 60 sec while the temperature was recorded with 10 sec intervals. Ultimately, the same tooth was hemisected bucco-lingually and the amalgam was removed. The same composite curing procedure was repeated while the thermogram was recorded using an infrared camera. Thereafter, the data was analyzed by repeated measured ANOVA followed by Tukey’s HSD Post Hoc test for multiple comparisons (α=0.05). Results: The pulp temperature was significantly increased (repeated measures) during photo polymerization (P=0.000) while there was no significant difference among the results recorded by thermocouple comparing to infrared camera (P>0.05). Moreover, different composite materials and LCUs lead to similar outcomes (P>0.05). Conclusion: Although various composites have significant different chemical compositions, they lead to similar pulp thermal changes. Moreover, both the infrared camera and the thermocouple would record parallel results of dental pulp temperature. PMID:29707014

Contribution of the Collagen-Binding Proteins of Streptococcus mutans to Bacterial Colonization of Inflamed Dental Pulp.

PubMed

Nomura, Ryota; Ogaya, Yuko; Nakano, Kazuhiko

2016-01-01

Streptococcus mutans is a major pathogen of dental caries. Collagen-binding proteins (CBPs) (approximately 120 kDa), termed Cnm and Cbm, are regarded as important cell surface antigens related to the adherence of S. mutans to collagenous tissue. Furthermore, CBP-positive S. mutans strains are associated with various systemic diseases involving bacteremia, such as infective endocarditis. Endodontic infection is considered to be an important cause of bacteremia, but little is known regarding the presence of S. mutans in dental pulp tissue. In the present study, the distribution and virulence of S. mutans in dental pulp tissues were investigated by focusing on CBPs. Adhesion and invasion properties of various S. mutans strains were analyzed using human dental pulp fibroblasts (HDPFs). CBP-positive strains had a significantly higher rate of adhesion to HDPFs compared with CBP-defective isogenic mutant strains (P<0.001). In addition, CBP-positive strains induced HDPF proliferation, which is a possible mechanism related to development of hyperplastic pulpitis. The distribution of S. mutans strains isolated from infected root canal specimens was then analyzed by PCR. We found that approximately 50% of the root canal specimens were positive for S. mutans. Approximately 20% of these strains were Cnm-positive, while no Cbm-positive strains were isolated. The Cnm-positive strains isolated from the specimens showed adhesion to HDPFs. Our results suggest that CBP-positive S. mutans strains exhibit high colonization in dental pulp. This could be a possible virulence factor for various systemic diseases.

Two Distinct Processes of Bone-like Tissue Formation by Dental Pulp Cells after Tooth Transplantation

PubMed Central

Yukita, Akira; Yoshiba, Kunihiko; Yoshiba, Nagako; Takahashi, Masafumi; Nakamura, Hiroaki

2012-01-01

Dental pulp is involved in the formation of bone-like tissue in response to external stimuli. However, the origin of osteoblast-like cells constructing this tissue and the mechanism of their induction remain unknown. We therefore evaluated pulp mineralization induced by transplantation of a green fluorescent protein (GFP)–labeled tooth into a GFP-negative hypodermis of host rats. Five days after the transplantation, the upper pulp cavity became necrotic; however, cell-rich hard tissue was observed adjacent to dentin at the root apex. At 10 days, woven bone-like tissue was formed apart from the dentin in the upper pulp. After 20 days, these hard tissues expanded and became histologically similar to bone. GFP immunoreactivity was detected in the hard tissue-forming cells within the root apex as well as in the upper pulp. Furthermore, immunohistochemical observation of α–smooth muscle actin, a marker for undifferentiated cells, showed a positive reaction in cells surrounding this bone-like tissue within the upper pulp but not in those within the root apex. Immunoreactivities of Smad4, Runx2, and Osterix were detected in the hard tissue-forming cells within both areas. These results collectively suggest that the dental pulp contains various types of osteoblast progenitors and that these cells might thus induce bone-like tissue in severely injured pulp. PMID:22899860

Histochemistry of nerve fibres double labelled with anti-TRPV2 antibodies and sensory nerve marker AM1-43 in the dental pulp of rat molars.

PubMed

Nishikawa, Sumio

2008-09-01

AM1-43 can label sensory nerve fibres and sensory neurons. Permeation of non-selective cation channels of the nerve cell membrane is suggested to be the mechanism responsible for labelling. To identify these channels, two candidates, TRPV1 and TRPV2 were examined by immunocytochemistry in the dental pulp and trigeminal ganglion of rats injected with AM1-43. A part of AM1-43-labelled nerve fibres was also positive for anti-TRPV2 antibody but negative for anti-TRPV1 antibody in the dental pulp. In the trigeminal ganglion, a part of the neuron showed both bright AM1-43 labelling and anti-TRPV2 immunolabelling, but neurons double labelled with AM1-43 and TRPV1 were rare. These results suggest that TRPV2 channels, but not TRPV1 channels, contribute to the fluorescent labelling of AM1-43 in the dental pulp.

HDAC inhibitor LMK-235 promotes the odontoblast differentiation of dental pulp cells

PubMed Central

Liu, Zhao; Chen, Ting; Han, Qianqian; Chen, Ming; You, Jie; Fang, Fuchun; Peng, Ling; Wu, Buling

2018-01-01

The role of dental pulp cells (DPCs) in hard dental tissue regeneration had received increasing attention because DPCs can differentiate into odontoblasts and other tissue-specific cells. In recent years, epigenetic modifications had been identified to serve an important role in cell differentiation, and histone deacetylase (HDAC) inhibitors have been widely studied by many researchers. However, the effects of HDAC4 and HDAC5 on the differentiation of DPCs and the precise molecular mechanisms remain unclear. The present study demonstrated that LMK-235, a specific human HDAC4 and HDAC5 inhibitor, increased the expression of specific odontoblastic gene expression levels detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in dental pulp cells, and did not reduce cell proliferation tested by MTT assay after 3 days in culture at a low concentration. In addition, the mRNA and protein expression levels of dentin sialophosphoprotein, runt-related transcription factor 2, alkaline phosphatase (ALP) and osteocalcin were evaluated by RT-qPCR and western blotting, respectively. The increased gene and protein expression of specific markers demonstrated, indicating that LMK-235 promoted the odontoblast induction of DPCs. ALP activity and mineralised nodule formation were also enhanced due to the effect of LMK-235, detected by an ALP activity test and Alizarin Red S staining, respectively. Additionally, the vascular endothelial growth factor (VEGF)/RAC-gamma serine/threonine-protein kinase (AKT)/mechanistic target of rapamycin (mTOR) signalling pathway was tested to see if it takes part in the differentiation of DPCs treated with LMK-235, and it was demonstrated that the mRNA expression levels of VEGF, AKT and mTOR were upregulated. These findings indicated that LMK-235 may serve a key role in the proliferation and odontoblast differentiation of DPCs, and could be used to accelerate dental tissue regeneration. PMID:29138868

Depth and activity of carious lesions as indicators for the regenerative potential of dental pulp after intervention.

PubMed

Bjørndal, Lars; Demant, Sune; Dabelsteen, Sally

2014-04-01

Studies on dental regeneration involving interventions for pulp therapy such as regeneration and revascularization procedures are promising for the injured tooth; however, a complete replication of the original pulp tissue does not seem to take place. In cases in which we wish to preserve or maintain parts of the pulp during treatment, it is apparent that the effectiveness of healing or biological regeneration is dependent on the degree of inflammation of the pulp tissue. Thus, the control or prevention of a pulp infection is still a major issue for the clinicians. Data indicate that the typical reason for performing endodontic treatment is deep caries. The biological concept of vital pulp therapy associated with deep caries takes the treatment and evaluation of the unexposed as well as the exposed pulp into account. Interestingly, the clinical diagnosis is typically the same. Deep caries with reversible pulpitis may receive differing treatments such as excavation procedures aiming to avoid pulp exposure or more pulp invasive treatments such as pulp capping or pulpotomy. This should not be the case. Consequently, huge treatment variation is noted among clinicians based on the same caries diagnosis. Which treatment should be selected? High-quality trials are needed, and it is important to obtain information on the actual lesion depth and an estimate of the lesion activity before treatment. These may be basic indicators for the regenerative potential of dental pulp. Recent clinical trials dealing with the treatment of deep caries lesion are discussed, including pulp invasive and noninvasive concepts, to attempt to solve the task of getting the best clinical outcome for adult patients. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Human Dental Pulp Stem Cells Suppress Alloantigen-induced Immunity by Stimulating T Cells to Release Transforming Growth Factor Beta.

PubMed

Kwack, Kyu Hwan; Lee, Jung Min; Park, Sang Hyuk; Lee, Hyeon Woo

2017-01-01

Human dental pulp stem cells (hDPSCs) are ideal candidates for regenerating damaged dental tissue. To examine the possibility that hDPSCs may be used to regenerate pulp, we tested their in vitro effects on acute allogeneic immune responses. A peripheral blood mononuclear cell (PBMC) proliferation assay and immunoglobulin (Ig) production assay were performed to evaluate the immunosuppressive properties of hDPSCs. The mixed lymphocyte reaction was suppressed by incubation with hDPSCs. Transforming growth factor beta (TGF-β) was the major soluble factor responsible for inhibiting the allogeneic proliferation of PBMCs. The production of IgM and IgG by allogeneic activation of responder B lymphocytes was also completely abrogated by TGF-β released from hDPSCs via interferon gamma in response to activation of the responder T lymphocytes. hDPSCs inhibit acute allogeneic immune responses by their release of TGF-β as a result of allogeneic stimulation of T lymphocytes. This study provides an insight into the potential clinical use of hDPSCs for allogeneic transplantation. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Photoacoustic detection of blood in dental pulp by using short-time Fourier transform

NASA Astrophysics Data System (ADS)

Yamada, Azusa; Kakino, Satoko; Matsuura, Yuji

2016-03-01

A method based on photoacoustic analysis is proposed to diagnose dental pulp vitality. Photoacoustic analysis enables to get signal from deeper tissues than other optical analyses and therefore, signal detection from root canal of thick dental tissues such as molar teeth is expected. As a light source for excitation of photoacoustic waves, a microchip Q-switched YAG laser with a wavelength of 1064 nm was used and owing to large penetration depth of the near infrared laser, photoacoustic signals from dental root were successfully obtained. It was found that the photoacoustic signals from the teeth containing hemoglobin solution in the pulp cavity provide vibration in high frequency region. It was also shown that the intensities of the high frequency component have correlation with the hemoglobin concentration of solution. We applied short-time Fourier transform for evaluation of photoacoustic signals and this analysis clearly showed photoacoustic signals from dental root.

Efficacy of Sex Determination from Human Dental Pulp Tissue and its Reliability as a Tool in Forensic Dentistry

PubMed Central

Khanna, Kaveri Surya

2015-01-01

Background: Sex determination is one of the primary steps in forensics. Barr body can be used as a histological method for identification of sex as it is found to be specific to female somatic cells and rare in male cells. To demarcate human dental pulp as an important identification tool of sex in forensic odontology (FO) and to evaluate the time period till which sex can be determined from pulp tissue using three stains H and E, Feulgen, and acridine - orange under fluorescence so as. Materials and Methods: 90 pulp samples (45 males and 45 females) were subjected to Barr body analysis for determination of sex using light and fluorescent microscopy. Results: Barr body was found to be positive for female samples and negative or rare in the male sample (<3%). Conclusion: Barr body from human dental pulp tissue can be used as a successful determinant of sex identification in FO. PMID:26668474

Cryopreservation Method for the Effective Collection of Dental Pulp Stem Cells.

PubMed

Takebe, Yusuke; Tatehara, Seiko; Fukushima, Tatsuhiro; Tokuyama-Toda, Reiko; Yasuhara, Rika; Mishima, Kenji; Satomura, Kazuhito

2017-05-01

Dental pulp stem cells (DPSCs) are an attractive cell source for use in cell-based therapy, regenerative medicine, and tissue engineering because DPSCs have a high cell proliferation ability and multidifferentiation capacity. However, several problems are associated with the collection and preservation of DPSCs for use in future cell-based therapy. In particular, the isolation of DPSCs for cryopreservation is time consuming and expensive. In this study, we developed a novel cryopreservation method (NCM) for dental pulp tissues to isolate suitable DPSCs after thawing cryopreserved tissue. Using the NCM, dental pulp tissues were cultured on adhesion culture dishes for 5 days and then cryopreserved. After thawing, the cryopreserved dental pulp tissue fragments exhibited cell migration. We evaluated each property of DPSCs isolated using the NCM (DPSCs-NCM) and the explant method alone without cryopreservation (DPSCs-C). DPSCs-NCM had the same proliferation capacity as DPSCs-C. Flow cytometry (FACS) analysis indicated that both DPSCs-NCM and DPSCs-C were positive for mesenchymal stem cell markers at the same level but negative for hematopoietic cell markers. Moreover, both DPSCs-NCM and DPSCs-C could differentiate into osteogenic, chondrogenic, and adipogenic cells during culture in each induction medium. These results suggest that DPSCs-NCM may be mesenchymal stem cells. Therefore, our novel method might facilitate the less expensive cryopreservation of DPSCs, thereby providing suitable DPSCs for use in patients in future cell-based therapies.

Synthetic Light-Curable Polymeric Materials Provide a Supportive Niche for Dental Pulp Stem Cells.

PubMed

Vining, Kyle H; Scherba, Jacob C; Bever, Alaina M; Alexander, Morgan R; Celiz, Adam D; Mooney, David J

2018-01-01

Dental disease annually affects billions of patients, and while regenerative dentistry aims to heal dental tissue after injury, existing polymeric restorative materials, or fillings, do not directly participate in the healing process in a bioinstructive manner. There is a need for restorative materials that can support native functions of dental pulp stem cells (DPSCs), which are capable of regenerating dentin. A polymer microarray formed from commercially available monomers to rapidly identify materials that support DPSC adhesion is used. Based on these findings, thiol-ene chemistry is employed to achieve rapid light-curing and minimize residual monomer of the lead materials. Several triacrylate bulk polymers support DPSC adhesion, proliferation, and differentiation in vitro, and exhibit stiffness and tensile strength similar to existing dental materials. Conversely, materials composed of a trimethacrylate monomer or bisphenol A glycidyl methacrylate, which is a monomer standard in dental materials, do not support stem cell adhesion and negatively impact matrix and signaling pathways. Furthermore, thiol-ene polymerized triacrylates are used as permanent filling materials at the dentin-pulp interface in direct contact with irreversibly injured pulp tissue. These novel triacrylate-based biomaterials have potential to enable novel regenerative dental therapies in the clinic by both restoring teeth and providing a supportive niche for DPSCs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Enhanced differentiation of dental pulp cells cultured on microtubular polymer scaffolds in vitro.

PubMed

Haeri, Morteza; Sagomonyants, Karen; Mina, Mina; Kuhn, Liisa T; Goldberg, A Jon

2017-06-01

Dental caries (tooth decay) is the most common chronic disease. Dental tissue engineering is a promising alternative approach to alleviate the shortcomings of the currently available restorative materials. Mimicking the natural extracellular matrix (ECM) could enhance the performance of tissue engineering scaffolds. In this study, we developed microtubular (~20 μm diameter) polymethyl methacrylate (PMMA) scaffolds resembling the tubular (~2.5 μm diameter) structure of dentin, the collagen-based mineralized tissue that forms the major portion of teeth, to study the effect of scaffold architecture on differentiation of mouse dental pulp cells in vitro . Flat (control), plasma-treated solid and microtubular PMMA scaffolds with densities of 240±15, 459±51 and 480±116 tubules/mm 2 were first characterized using scanning electron microscopy and contact angle measurements. Dental pulp cells were cultured on the surface of the scaffolds for up to 21 days and examined using various assays. Cell proliferation and mineralization were examined using Alamar Blue and Xylenol Orange (XO) staining assays, respectively. The differentiation of pulp cells into odontoblasts was examined by immunostaining for Nestin and by quantitative PCR analysis for dentin matrix protein 1 ( Dmp1 ), dentin sialophosphoprotein ( Dspp ) and osteocalcin ( Ocn ). Our results showed that the highest tubular density scaffolds significantly (p<0.05) enhanced differentiation of pulp cells into odontoblasts as compared to control flat scaffolds, as evidenced by increased expression of Nestin (5.4x). However, mineralization was suppressed on all surfaces, possibly due to low cell density. These results suggest that the microtubular architecture may be a desirable feature of scaffolds developed for clinical applications. Regenerative engineering of diseased or traumatized tooth structure could avoid the deficiencies of traditional dental restorative (filling) materials. Cells in the dental pulp have the potential to differentiate to dentin-producing odontoblast cells. Furthermore, cell-supporting scaffolds that mimic a natural extracellular matrix (ECM) are known to influence behavior of progenitor cells. Accordingly, we hypothesized that a dentin-like microtubular scaffold would enhance differentiation of dental pulp cells. The hypothesis was proven true and differentiation to odontoblasts increased with increasing density of the microtubules. However, mineralization was suppressed, possibly due to a low density of cells. The results demonstrate the potential benefits of a microtubular scaffold design to promote odontoblast cells for regeneration of dentin.

Comparison of heat-testing methodology.

PubMed

Bierma, Mark M; McClanahan, Scott; Baisden, Michael K; Bowles, Walter R

2012-08-01

Patients with irreversible pulpitis occasionally present with a chief complaint of sensitivity to heat. To appropriately diagnose the offending tooth, a variety of techniques have been developed to reproduce this chief complaint. Such techniques cause temperature increases that are potentially damaging to the pulp. Newer electronic instruments control the temperature of a heat-testing tip that is placed directly against a tooth. The aim of this study was to determine which method produced the most consistent and safe temperature increase within the pulp. This consistency facilitates the clinician's ability to differentiate between a normal pulp and irreversible pulpitis. Four operators applied the following methods to each of 4 extracted maxillary premolars (for a total of 16 trials per method): heated gutta-percha, heated ball burnisher, hot water, and a System B unit or Elements unit with a heat-testing tip. Each test was performed for 60 seconds, and the temperatures were recorded via a thermocouple in the pulp chamber. Analysis of the data was performed by using the intraclass correlation coefficient. The least consistent warming was found with hot water. The heat-testing tip also demonstrated greater consistency between operators compared with the other methods. Hot water and the heated ball burnisher caused temperature increases high enough to damage pulp tissue. The Elements unit with a heat-testing tip provides the most consistent warming of the dental pulp. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Dynamic Hydrostatic Pressure Promotes Differentiation of Human Dental Pulp Stem Cells

PubMed Central

Yu, V; Damek-Poprawa, M.; Nicoll, S. B.; Akintoye, S.O.

2009-01-01

The masticatory apparatus absorbs high occlusal forces, but uncontrolled parafunctional or orthodontic forces damage periodontal ligament (PDL), cause pulpal calcification, pulp necrosis and tooth loss. Morphology and functional differentiation of connective tissue cells can be controlled by mechanical stimuli but effects of uncontrolled forces on intra-pulpal homeostasis and ability of dental pulp stem cells (DPSCs) to withstand direct external forces are unclear. Using dynamic hydrostatic pressure (HSP), we tested the hypothesis that direct HSP disrupts DPSC survival and odontogenic differentiation. DPSCs from four teenage patients were subjected to HSP followed by assessment of cell adhesion, survival and recovery capacity based on odontogenic differentiation, mineralization and responsiveness to bone morphogenetic protein-2 (BMP-2). HSP down-regulated DPSC adhesion and survival but promoted differentiation by increasing mineralization, in vivo hard tissue regeneration and BMP-2 responsiveness despite reduced cell numbers. HSP-treated DPSCs displayed enhanced odontogenic differentiation, an indication of favorable recovery from HSP-induced cellular stress. PMID:19555657

Effects of epinephrine on lidocaine pharmacokinetics and blood volume in the dental pulp.

PubMed

Hashimoto, Shuichi; Yamashiro, Mikiko; Fujita, Kyohei; Yasuda, Asako; Sunada, Katsuhisa

2014-09-01

Epinephrine potentiates and prolongs the efficacy of local anesthetics by reducing blood flow. We investigated the effect of epinephrine on the pharmacokinetics of lidocaine and the pulpal blood volume after maxillary infiltration anesthesia in rats. We measured the (14)C-radioactivity and (14)C-distribution in the maxilla and the dental pulp after the injection of 2% (14)C-lidocaine with or without 10 μg/mL epinephrine (n = 7) into the palatine mucosa proximal to the first molar. The blood volume in the pulp was measured using (99m)Tc-pertechnetate (n = 5). When lidocaine was injected together with epinephrine, the lidocaine became widely distributed throughout the maxilla and was observed mainly in the first molar pulp. The lidocaine amount in the dental pulp at 10-60 minutes was more than 2 times higher than that after the injection of lidocaine alone. The relative pulpal blood volume after 20 minutes decreased to 63.1% of the value after the injection of lidocaine alone. We found that lidocaine had infiltrated into the molar pulp after infiltration anesthesia. Furthermore, our results suggested that epinephrine augmented the retention of lidocaine in the pulp. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

A comparison of temperature increases produced by "premium" and "standard" diamond burs: An in-vitro study.

PubMed

Segal, Pnina; Sap, Danny; Ben-Amar, Ariel; Levartovsky, Shifra; Matalon, Shlomo

2016-02-01

Vital tooth preparations may cause irreversible thermal damage to the pulp. The manufacturing techniques of dental burs may decrease heat production and minimize the risk of overheating and trauma to the dental pulp. Strauss (Raanana, Israel) has introduced "premium" diamond burs, claiming superior efficiency and longevity. We sought to determine the safest preparation methods by performing a comparison of intrapulpal temperature increases caused with "standard" and "premium" burs. Three types of diamond burs (F1R, F21R, and K2) were tested on extracted human teeth (n = 8 teeth per bur type). Premium and standard manufacturing techniques were compared for each bur type (n = 24 teeth per group; total 48 teeth). An intrapulpal thermocouple was used to measure the temperature during the procedure. Comparisons were analyzed with the t test and one-way ANOVA. P ≤ .05 was considered significant. All premium burs demonstrated lower temperature increases compared to the standard burs (P ≤ .001 for F21R and K2, P = .086 for F1R). The temperature increases with premium burs were similar for different bur shapes, but the temperature increases with standard burs depended on the bur shape (P < .001). Using premium diamond burs for tooth preparation may reduce the risk of pulp tissue damage, and thus reduce postoperative pulp-associated complications.

Dentin barrier test with transfected bovine pulp-derived cells.

PubMed

Schmalz, G; Schuster, U; Thonemann, B; Barth, M; Esterbauer, S

2001-02-01

Growth kinetics of SV40 large T-antigen-transfected bovine pulp-derived cells on dentin were investigated. These cells were used in a dentin barrier test device, and the system was evaluated by testing a set of dental filling materials. Cells (120 cells/mm2) were seeded on dentin slices and incubated for up to 21 days. Cell proliferation was recorded using MTT assay. For cytotoxicity tests 3500 cells/mm2 were seeded on dentin discs, which were then incorporated into the dentin barrier test device. After 72 h preincubation test materials were applied. After a 24 h exposure with or without perfusion of the pulpal part of the test device, cell survival was evaluated using MTT assay. The cells revealed similar growth kinetics on dentin slices and on tissue culture plates. In cytotoxicity tests the cells were more sensitive toward the test materials than previously used three-dimensional cultures of human foreskin fibroblasts and as anticipated from clinical experience. Further improvement is expected by using three-dimensional cultures of pulp-derived cells.

Histological Evaluation to Study the Effects of Dental Amalgam and Composite Restoration on Human Dental Pulp: An in vivo Study

PubMed Central

Chandwani, Neelam D.; Pawar, Mansing G.; Tupkari, Jagdish V.; Yuwanati, Monal

2013-01-01

Objective To study and compare the effects of dental amalgam and composite restorations on human dental pulp. Materials and Methods One hundred sound premolars scheduled for orthodontic extraction were divided equally into two groups: group A, teeth restored with silver amalgam, and group B, teeth restored with composite resin. Each group was equally subdivided into two subgroups [extracted after 24 h (A-1 and B-1) or 7 days (A−2 and B−2)], and the histological changes in the pulp related to the two different materials at the two different intervals were studied. Results It was found that after 24 h, the inflammatory response of the pulp in teeth restored with amalgam and composite was similar (p = 1.00). However, after 7 days, the severity of the inflammatory response of the pulp in teeth restored with amalgam was less compared to that in teeth restored with composite (p = 0.045). Conclusion This study confirmed that amalgam continues to be the mechanically as well as biologically more competent restorative material. Composite could be a promising restorative material to satisfy esthetic needs for a considerable period of time. However, its biological acceptance is still in doubt. PMID:24217468

Isolation and morphology of Stem Cells from Deciduous Tooth (SHED) and Human Dental Pulp Stem Cells (hDPSC)

NASA Astrophysics Data System (ADS)

Ariffin, Shahrul Hisham Zainal; Manogaran, Thanaletchumi; Abidin, Intan Zarina Zainol; Senafi, Sahidan; Wahab, Rohaya Megat Abdul

2016-11-01

Dental pulp is a tissue obtained from pulp chamber of deciduous and permanent tooth which contain stem cells. Stem cell isolation procedure is performed to obtain cells from tissue using enzymatic digestion. The aim of this study is to isolate and observe the morphology of stem cells during passage 0 and passage 3. Dental pulp from deciduous and permanent tooth was enzymatically digested using collagenase Type I and cells obtained were cultured in DMEM-KO that contains 10% fetal bovine serum, 1% antibiotic-antimycotic solution and 0.001× GlutaMax®. During culture, cell morphology was observed under the microscope on day 3, 16 and 33 and captured using cellB software. Giemsa staining was conducted on cells at passage 3. Cells attached at the bottom of the flask on day 3 and started forming small colonies. Cells became confluent after approximately 4 weeks. Both Stem Cells from Deciduous Tooth (SHED) and Human Dental Pulp Stem Cells (hDPSC) exhibited fibroblast-like morphology during passage 0 and passage 3. Meanwhile, Giemsa staining at passage 3 revealed single intact nucleus surrounded by fibroblastic cytoplasm structure. It can be concluded that SHED and hDPSC showed consistent fibroblast-like morphology throughout culture period.

Capsaicin-evoked iCGRP release from human dental pulp: a model system for the study of peripheral neuropeptide secretion in normal healthy tissue

PubMed Central

Fehrenbacher, Jill C.; Sun, Xiaoling X.; Locke, Erin E.; Henry, Michael A.; Hargreaves, Kenneth M.

2009-01-01

The mechanisms underlying trigeminal pain conditions are incompletely understood. In vitro animal studies have elucidated various targets for pharmacological intervention; however, a lack of clinical models that allow evaluation of viable innervated human tissue has impeded successful translation of many preclinical findings into clinical therapeutics. Therefore, we developed and characterized an in vitro method that evaluates the responsiveness of isolated human nociceptors by measuring basal and stimulated release of neuropeptides from collected dental pulp biopsies. Informed consent was obtained from patients presenting for extraction of normal wisdom teeth. Patients were anesthetized using nerve block injection, teeth were extracted and bisected, and pulp was removed and superfused in vitro. Basal and capsaicin-evoked peripheral release of immunoreactive calcitonin gene-related peptide (iCGRP) was analyzed by enzyme immunoassay. The presence of nociceptive markers within neurons of the dental pulp was characterized using confocal microscopy. Capsaicin increased the release of iCGRP from dental pulp biopsies in a concentration-dependent manner. Stimulated release was dependent on extracellular calcium, reversed by a TRPV1 receptor antagonist, and desensitized acutely (tachyphylaxis) and pharmacologically by pretreatment with capsaicin. Superfusion with phorbol 12-myristate 13-acetate (PMA) increased basal and stimulated release, whereas PGE2 augmented only basal release. Compared with vehicle treatment, pretreatment with PGE2 induced competence for DAMGO to inhibit capsaicin-stimulated iCGRP release, similar to observations in animal models where inflammatory mediators induce competence for opioid inhibition. These results indicate the release of iCGRP from human dental pulp provides a novel tool to determine the effects of pharmacological compounds on human nociceptor sensitivity. PMID:19428185

Effects of Extracellular pH on Dental Pulp Cells In Vitro.

PubMed

Hirose, Yujiro; Yamaguchi, Masaya; Kawabata, Shigetada; Murakami, Masashi; Nakashima, Misako; Gotoh, Momokazu; Yamamoto, Tokunori

2016-05-01

The proliferation and migration of dental pulp stem cells (DPSCs), a population comprised of dental pulp cells (DPCs), are important processes for pulp tissue repair. Dental pulp is exposed to changes in extracellular pH under various conditions, such as acidosis and exposure to caries-associated bacteria or a pulp capping agent. The objective of this study was to investigate the effects of extracellular pH on DPC proliferation and migration in vitro. To evaluate the proliferation potency of DPCs in various extracellular pH conditions, 2 × 10(4) cells were seeded into 35-mm dishes. The following day, we changed to NaHCO3-free medium, which was adjusted to different extracellular pH levels. After 120 hours, DPCs cultured in media from a pH of 3.5 to 5.5 showed cell death, those cultured in conditions from a pH of 6.5 to 7.5 showed growth arrest or cell death, and those grown at a pH of 9.5 showed mild proliferation. The migratory activity of living DPCs was not affected by extracellular pH. For histologic analysis, human teeth possessing a small abscess in the coronal pulp chamber were sliced for histologic analysis. Proliferating cell nuclear antigen (PCNA) immunolocalization was used as an index of cell proliferation for the sections and cultured cells. Acidic extracellular pH conditions resulted in reduced numbers of PCNA-positive DPCs in the dishes. As for pulp tissue affected by a small abscess, a PCNA-negative pulp cell layer was observed in close proximity to the infectious lesion. Together, these results suggest that an acidic extracellular pH condition is associated with DPC growth arrest or cell death. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Imperative role of dental pulp stem cells in regenerative therapies: a systematic review.

PubMed

Kabir, Ramchandra; Gupta, Manish; Aggarwal, Avanti; Sharma, Deepak; Sarin, Anurag; Kola, Mohammed Zaheer

2014-01-01

Stem cells are primitive cells that can differentiate and regenerate organs in different parts of the body such as heart, bones, muscles and nervous system. This has been a field of great clinical interest with immense possibilities of using the stem cells in regeneration of human organ those are damaged due to disease, developmental defects and accident. The knowledge of stem cell technology is increasing quickly in all medical specialties and in dental field too. Stem cells of dental origin appears to hold the key to various cell-based therapies in regenerative medicine, but most avenues are in experimental stages and many procedures are undergoing standardization and validation. Long-term preservation of SHED cells or DPSC is becoming a popular consideration, similar to the banking of umbilical cord blood. Dental pulp stem cells (DPSCs) are the adult multipotent cells that reside in the cell rich zone of the dental pulp. The multipotent nature of these DPSCs may be utilized in both dental and medical applications. A systematic review of the literature was performed using various internet based search engines (PubMed, Medline Plus, Cochrane, Medknow, Ebsco, Science Direct, Hinari, WebMD, IndMed, Embase) using keywords like "dental pulp stem cells", "regeneration", "medical applications", "tissue engineering". DPSCs appears to be a promising innovation for the re-growth of tissues however, long term clinical studies need to be carried out that could establish some authentic guidelines in this perspective.

Imperative Role of Dental Pulp Stem Cells in Regenerative Therapies: A Systematic Review

PubMed Central

Kabir, Ramchandra; Gupta, Manish; Aggarwal, Avanti; Sharma, Deepak; Sarin, Anurag; Kola, Mohammed Zaheer

2014-01-01

Stem cells are primitive cells that can differentiate and regenerate organs in different parts of the body such as heart, bones, muscles and nervous system. This has been a field of great clinical interest with immense possibilities of using the stem cells in regeneration of human organ those are damaged due to disease, developmental defects and accident. The knowledge of stem cell technology is increasing quickly in all medical specialties and in dental field too. Stem cells of dental origin appears to hold the key to various cell-based therapies in regenerative medicine, but most avenues are in experimental stages and many procedures are undergoing standardization and validation. Long-term preservation of SHED cells or DPSC is becoming a popular consideration, similar to the banking of umbilical cord blood. Dental pulp stem cells (DPSCs) are the adult multipotent cells that reside in the cell rich zone of the dental pulp. The multipotent nature of these DPSCs may be utilized in both dental and medical applications. A systematic review of the literature was performed using various internet based search engines (PubMed, Medline Plus, Cochrane, Medknow, Ebsco, Science Direct, Hinari, WebMD, IndMed, Embase) using keywords like “dental pulp stem cells”, “regeneration”, “medical applications”, “tissue engineering”. DPSCs appears to be a promising innovation for the re-growth of tissues however, long term clinical studies need to be carried out that could establish some authentic guidelines in this perspective. PMID:24665194

Allogenic banking of dental pulp stem cells for innovative therapeutics.

PubMed

Collart-Dutilleul, Pierre-Yves; Chaubron, Franck; De Vos, John; Cuisinier, Frédéric J

2015-08-26

Medical research in regenerative medicine and cell-based therapy has brought encouraging perspectives for the use of stem cells in clinical trials. Multiple types of stem cells, from progenitors to pluripotent stem cells, have been investigated. Among these, dental pulp stem cells (DPSCs) are mesenchymal multipotent cells coming from the dental pulp, which is the soft tissue within teeth. They represent an interesting adult stem cell source because they are recovered in large amount in dental pulps with non-invasive techniques compared to other adult stem cell sources. DPSCs can be obtained from discarded teeth, especially wisdom teeth extracted for orthodontic reasons. To shift from promising preclinical results to therapeutic applications to human, DPSCs must be prepared in clinical grade lots and transformed into advanced therapy medicinal products (ATMP). As the production of patient-specific stem cells is costly and time-consuming, allogenic biobanking of clinical grade human leukocyte antigen (HLA)-typed DPSC lines provides efficient innovative therapeutic products. DPSC biobanks represent industrial and therapeutic innovations by using discarded biological tissues (dental pulps) as a source of mesenchymal stem cells to produce and store, in good manufacturing practice (GMP) conditions, DPSC therapeutic batches. In this review, we discuss about the challenges to transfer biological samples from a donor to HLA-typed DPSC therapeutic lots, following regulations, GMP guidelines and ethical principles. We also present some clinical applications, for which there is no efficient therapeutics so far, but that DPSCs-based ATMP could potentially treat.

Allogenic banking of dental pulp stem cells for innovative therapeutics

PubMed Central

Collart-Dutilleul, Pierre-Yves; Chaubron, Franck; De Vos, John; Cuisinier, Frédéric J

2015-01-01

Medical research in regenerative medicine and cell-based therapy has brought encouraging perspectives for the use of stem cells in clinical trials. Multiple types of stem cells, from progenitors to pluripotent stem cells, have been investigated. Among these, dental pulp stem cells (DPSCs) are mesenchymal multipotent cells coming from the dental pulp, which is the soft tissue within teeth. They represent an interesting adult stem cell source because they are recovered in large amount in dental pulps with non-invasive techniques compared to other adult stem cell sources. DPSCs can be obtained from discarded teeth, especially wisdom teeth extracted for orthodontic reasons. To shift from promising preclinical results to therapeutic applications to human, DPSCs must be prepared in clinical grade lots and transformed into advanced therapy medicinal products (ATMP). As the production of patient-specific stem cells is costly and time-consuming, allogenic biobanking of clinical grade human leukocyte antigen (HLA)-typed DPSC lines provides efficient innovative therapeutic products. DPSC biobanks represent industrial and therapeutic innovations by using discarded biological tissues (dental pulps) as a source of mesenchymal stem cells to produce and store, in good manufacturing practice (GMP) conditions, DPSC therapeutic batches. In this review, we discuss about the challenges to transfer biological samples from a donor to HLA-typed DPSC therapeutic lots, following regulations, GMP guidelines and ethical principles. We also present some clinical applications, for which there is no efficient therapeutics so far, but that DPSCs-based ATMP could potentially treat. PMID:26328017

New Approaches in Vital Pulp Therapy in Permanent Teeth

PubMed Central

Ghoddusi, Jamileh; Forghani, Maryam; Parisay, Iman

2014-01-01

Vitality of dental pulp is essential for long-term tooth survival. The aim of vital pulp therapy is to maintain healthy pulp tissue by eliminating bacteria from the dentin-pulp complex. There are several different treatment options for vital pulp therapy in extensively decayed or traumatized teeth. Pulp capping or pulpotomy procedures rely upon an accurate assessment of the pulp status, and careful management of the remaining pulp tissue. The purpose of this review is to provide an overview of new approaches in vital pulp therapy in permanent teeth. PMID:24396371

SEM evaluation of pulp reaction to different pulp capping materials in dog’s teeth

PubMed Central

Asgary, Saeed; Parirokh, Masoud; Eghbal, Mohammad Jafar; Ghoddusi, Jamileh

2006-01-01

Introduction: This investigation evaluates the effects of mineral trioxide aggregate (MTA), calcium hydroxide (CH) and calcium enriched mixture (CEM) as pulp capping materials on dental pulp tissues. Materials and Methods: The experimental procedures were performed on eighteen intact dog canine teeth. The pulps were exposed. Cavities were randomly filled with CEM, MTA, or CH followed by glass ionomer filling. After 2 months, animals were sacrificed, each tooth was sectioned into halves, and the interface between each capping material and pulp tissue was evaluated by scanning electron microscope (SEM) in profile view of the specimens. Results: Dentinal bridge formation as the most characteristic reaction was resulted from SEM observation in all examined groups. Odontoblast-like cells were formed and create dens collagen network, which was calcified gradually by deposition of calcosphirit structures to form newly dentinal bridge. Conclusion: Based on the results of this in vivo study, it was concluded that these test materials are able to produce calcified tissue in underlying pulp in the case of being used as a pulp capping agent. Additionally, it appears that CEM has the potential to be used as a direct pulp capping material during vital pulp therapy. PMID:24379876

Assessment of the Tumorigenic Potential of Spontaneously Immortalized and hTERT-Immortalized Cultured Dental Pulp Stem Cells

PubMed Central

Wilson, Ryan; Urraca, Nora; Skobowiat, Cezary; Hope, Kevin A.; Miravalle, Leticia; Chamberlin, Reed; Donaldson, Martin; Seagroves, Tiffany N.

2015-01-01

Dental pulp stem cells (DPSCs) provide an exciting new avenue to study neurogenetic disorders. DPSCs are neural crest-derived cells with the ability to differentiate into numerous tissues including neurons. The therapeutic potential of stem cell-derived lines exposed to culturing ex vivo before reintroduction into patients could be limited if the cultured cells acquired tumorigenic potential. We tested whether DPSCs that spontaneously immortalized in culture acquired features of transformed cells. We analyzed immortalized DPSCs for anchorage-independent growth, genomic instability, and ability to differentiate into neurons. Finally, we tested both spontaneously immortalized and human telomerase reverse transcriptase (hTERT)-immortalized DPSC lines for the ability to form tumors in immunocompromised animals. Although we observed increased colony-forming potential in soft agar for the spontaneously immortalized and hTERT-immortalized DPSC lines relative to low-passage DPSC, no tumors were detected from any of the DPSC lines tested. We noticed some genomic instability in hTERT-immortalized DPSCs but not in the spontaneously immortalized lines tested. We determined that immortalized DPSC lines generated in our laboratory, whether spontaneously or induced, have not acquired the potential to form tumors in mice. These data suggest cultured DPSC lines that can be differentiated into neurons may be safe for future in vivo therapy for neurobiological diseases. Significance This study demonstrated that immortalized dental pulp stem cells (DPSCs) do not form tumors in animals and that immortalized DPSCs can be differentiated into neurons in culture. These results lend support to the use of primary and immortalized DPSCs for future therapeutic approaches to treatment of neurobiological diseases. PMID:26032749

Elevated extracellular calcium increases expression of bone morphogenetic protein-2 gene via a calcium channel and ERK pathway in human dental pulp cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tada, Hiroyuki; Nemoto, Eiji, E-mail: e-nemoto@umin.ac.jp; Kanaya, Sousuke

Dental pulp cells, which have been shown to share phenotypical features with osteoblasts, are capable of differentiating into odontoblast-like cells and generating a dentin-like mineral structure. Elevated extracellular Ca{sup 2+}Ca{sub o}{sup 2+} has been implicated in osteogenesis by stimulating the proliferation and differentiation of osteoblasts; however, the role of Ca{sub o}{sup 2+} signaling in odontogenesis remains unclear. We found that elevated Ca{sub o}{sup 2+} increases bone morphogenetic protein (BMP)-2 gene expression in human dental pulp cells. The increase was modulated not only at a transcriptional level but also at a post-transcriptional level, because treatment with Ca{sup 2+} increased the stabilitymore » of BMP-2 mRNA in the presence of actinomycin D, an inhibitor of transcription. A similar increase in BMP-2 mRNA level was observed in other human mesenchymal cells from oral tissue; periodontal ligament cells and gingival fibroblasts. However, the latter cells exhibited considerably lower expression of BMP-2 mRNA compared with dental pulp cells and periodontal ligament cells. The BMP-2 increase was markedly inhibited by pretreatment with an extracellular signal-regulated kinase (ERK) inhibitor, PD98059, and partially inhibited by the L-type Ca{sup 2+} channels inhibitor, nifedipine. However, pretreatment with nifedipine had no effect on ERK1/2 phosphorylation triggered by Ca{sup 2+}, suggesting that the Ca{sup 2+} influx from Ca{sup 2+} channels may operate independently of ERK signaling. Dental pulp cells do not express the transcript of Ca{sup 2+}-sensing receptors (CaSR) and only respond slightly to other cations such as Sr{sup 2+} and spermine, suggesting that dental pulp cells respond to Ca{sub o}{sup 2+} to increase BMP-2 mRNA expression in a manner different from CaSR and rather specific for Ca{sub o}{sup 2+} among cations.« less

Biophysical characterization of low-frequency ultrasound interaction with dental pulp stem cells

PubMed Central

2013-01-01

Background Low-intensity ultrasound is considered an effective non-invasive therapy to stimulate hard tissue repair, in particular to accelerate delayed non-union bone fracture healing. More recently, ultrasound has been proposed as a therapeutic tool to repair and regenerate dental tissues. Our recent work suggested that low-frequency kilohertz-range ultrasound is able to interact with dental pulp cells which could have potential to stimulate dentine reparative processes and hence promote the viability and longevity of teeth. Methods In this study, the biophysical characteristics of low-frequency ultrasound transmission through teeth towards the dental pulp were explored. We conducted cell culture studies using an odontoblast-like/dental pulp cell line, MDPC-23. Half of the samples underwent ultrasound exposure while the other half underwent ‘sham treatment’ where the transducer was submerged into the medium but no ultrasound was generated. Ultrasound was applied directly to the cell cultures using a therapeutic ultrasound device at a frequency of 45 kHz with intensity settings of 10, 25 and 75 mW/cm2 for 5 min. Following ultrasound treatment, the odontoblast-like cells were detached from the culture using a 0.25% Trypsin/EDTA solution, and viable cell numbers were counted. Two-dimensional tooth models based on μ-CT 2D images of the teeth were analyzed using COMSOL as the finite element analysis platform. This was used to confirm experimental results and to demonstrate the potential theory that with the correct combination of frequency and intensity, a tooth can be repaired using small doses of ultrasound. Frequencies in the 30 kHz–1 MHz range were analyzed. For each frequency, pressure/intensity plots provided information on how the intensity changes at each point throughout the propagation path. Spatial peak temporal average (SPTA) intensity was calculated and related to existing optimal spatial average temporal average (SATA) intensity deemed effective for cell proliferation during tooth repair. Results The results demonstrate that odontoblast MDPC-23 cell numbers were significantly increased following three consecutive ultrasound treatments over a 7-day culture period as compared with sham controls underscoring the anabolic effects of ultrasound on these cells. Data show a distinct increase in cell number compared to the sham data after ultrasound treatment for intensities of 10 and 25 mW/cm2 (p < 0.05 and p < 0.01, respectively). Using finite element analysis, we demonstrated that ultrasound does indeed propagate through the mineralized layers of the teeth and into the pulp chamber where it forms a ‘therapeutic’ force field to interact with the living dental pulp cells. This allowed us to observe the pressure/intensity of the wave as it propagates throughout the tooth. A selection of time-dependent snapshots of the pressure/intensity reveal that the lower frequency waves propagate to the pulp and remain within the chamber for a while, which is ideal for cell excitation. Input frequencies and pressures of 30 kHz (70 Pa) and 45 kHz (31 kPa), respectively, with an average SPTA of up to 120 mW/cm2 in the pulp seem to be optimal and agree with the SATA intensities reported experimentally. Conclusions Our data suggest that ultrasound can be harnessed to propagate to the dental pulp region where it can interact with the living cells to promote dentine repair. Further research is required to analyze the precise physical and biological interactions of low-frequency ultrasound with the dental pulp to develop a novel non-invasive tool for dental tissue regeneration. PMID:25516801

Vital Pulp Therapy of a Mature Molar with Concurrent Hyperplastic Pulpitis, Internal Root Resorption and Periradicular Periodontitis: A Case Report.

PubMed

Asgary, Saeed; Kemal Çalışkan, Mehmet

2015-01-01

Vital pulp therapy (VPT) of permanent mature teeth is continuously ascertaining to be a more reliable endodontic treatment. The purpose of this case report was to describe successful VPT of a mature mandibular left first molar with concurrent hyperplastic pulpitis, internal root resorption and periradicular periodontitis in a 35-year-old male patient. After complete caries removal and access cavity preparation, the dental pulp was removed from the coronal third of the roots. To protect the remaining pulp, calcium-enriched mixture (CEM) cement was placed and adapted into the cavities; the tooth was then restored with amalgam. Six months after VPT, radiographic examination showed evidence of periradicular healing. Clinically, the tooth was functional without signs and symptoms of infection/inflammation. The successful outcome of this case suggests that diseased dental pulp (i.e. irreversible pulpitis) has the potential to heal after pulp protection with CEM biocement.

Can dental pulp calcification predict the risk of ischemic cardiovascular disease?

PubMed

Khojastepour, Leila; Bronoosh, Pegah; Khosropanah, Shahdad; Rahimi, Elham

2013-09-01

To report the association of pulp calcification with that of cardiovascular disease (CVD) using digital panoramic dental radiographs. Digital panoramic radiographs of patients referred from the angiography department were included if the patient was under 55 years old and had non-restored or minimally restored molars and canines. An oral and maxillofacial radiologist evaluated the images for pulpal calcifications in the selected teeth. The sensitivity, specificity, positive predictive value and negative predictive value of panoramic radiography in predicting CVD were calculated. Out of 122 patients who met the criteria, 68.2% of the patients with CVD had pulp chamber calcifications. Pulp calcification in panoramic radiography had a sensitivity of 68.9% to predict CVD. This study demonstrates that patients with CVD show an increased incidence of pulp calcification compared with healthy patients. The findings suggest that pulp calcification on panoramic radiography may have possibilities for use in CVD screening.

Age-related Changes in the Alkaline Phosphatase Activity of Healthy and Inflamed Human Dental Pulp.

PubMed

Aslantas, Eda E; Buzoglu, Hatice Dogan; Karapinar, Senem Pinar; Cehreli, Zafer C; Muftuoglu, Sevda; Atilla, Pergin; Aksoy, Yasemin

2016-01-01

Alkaline phosphatase (ALP) plays an important role in inducing mineralization events in the dental pulp. This study investigated and compared the ALP levels in healthy and inflamed pulp in young and old human pulp. Tissue samples were collected from young (<30 years) and old (>60 years) donors. In both age groups, healthy human pulp (n = 18) were collected from extracted wisdom teeth. For reversible and irreversible pulpitis, pulp samples (n = 18 each) were obtained during endodontic treatment. ALP activity was assessed by spectrophotometry and immunhistochemistry. Regardless of age, reversible pulpitis group samples showed a slight elevation in ALP activity compared with normal healthy pulp. In elderly patients, ALP expression with irreversible pulpitis was significantly higher than those with a healthy pulp (P < .05). In the hyperemic state, both the young and old pulp shows a slight increase in ALP activity, whereas in irreversible pulpitis, only the old pulp shows significantly elevated ALP levels. Such an increase may trigger calcification events, which may eventually cause difficulties in endodontic treatment procedures in elderly individuals. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Transplantation of Human Dental Pulp-Derived Stem Cells or Differentiated Neuronal Cells from Human Dental Pulp-Derived Stem Cells Identically Enhances Regeneration of the Injured Peripheral Nerve.

PubMed

Ullah, Imran; Park, Ju-Mi; Kang, Young-Hoon; Byun, June-Ho; Kim, Dae-Geon; Kim, Joo-Heon; Kang, Dong-Ho; Rho, Gyu-Jin; Park, Bong-Wook

2017-09-01

Human dental mesenchymal stem cells isolated from the dental follicle, pulp, and root apical papilla of extracted wisdom teeth have been known to exhibit successful and potent neurogenic differentiation capacity. In particular, human dental pulp-derived stem cells (hDPSCs) stand out as the most prominent source for in vitro neuronal differentiation. In this study, to evaluate the in vivo peripheral nerve regeneration potential of hDPSCs and differentiated neuronal cells from DPSCs (DF-DPSCs), a total of 1 × 10 6 hDPSCs or DF-hDPSCs labeled with PKH26 tracking dye and supplemented with fibrin glue scaffold and collagen tubulization were transplanted into the sciatic nerve resection (5-mm gap) of rat models. At 12 weeks after cell transplantation, both hDPSC and DF-hDPSC groups showed notably increased behavioral activities and higher muscle contraction forces compared with those in the non-cell transplanted control group. In immunohistochemical analysis of regenerated nerve specimens, specific markers for angiogenesis, axonal fiber, and myelin sheath increased in both the cell transplantation groups. Pretransplanted labeled PKH26 were also distinctly detected in the regenerated nerve tissues, indicating that transplanted cells were well-preserved and differentiated into nerve cells. Furthermore, no difference was observed in the nerve regeneration potential between the hDPSC and DF-hDPSC transplanted groups. These results demonstrate that dental pulp tissue is an excellent stem cell source for nerve regeneration, and in vivo transplantation of the undifferentiated hDPSCs could exhibit sufficient and excellent peripheral nerve regeneration potential.

Wnt5a Promotes Inflammatory Responses via Nuclear Factor κB (NF-κB) and Mitogen-activated Protein Kinase (MAPK) Pathways in Human Dental Pulp Cells*

PubMed Central

Zhao, Yuan; Wang, Chen-Lin; Li, Rui-Min; Hui, Tian-Qian; Su, Ying-Ying; Yuan, Quan; Zhou, Xue-Dong; Ye, Ling

2014-01-01

Wnt5a has been found recently to be involved in inflammation regulation through a mechanism that remains unclear. Immunohistochemical staining of infected human dental pulp and tissue from experimental dental pulpitis in rats showed that Wnt5a levels were increased. In vitro, Wnt5a was increased 8-fold in human dental pulp cells (HDPCs) after TNF-α stimulation compared with control cells. We then investigated the role of Wnt5a in HDPCs. In the presence of TNF-α, Wnt5a further increased the production of cytokines/chemokines, whereas Wnt5a knockdown markedly reduced cytokine/chemokine production induced by TNF-α. In addition, in HDPCs, Wnt5a efficiently induced cytokine/chemokine expression and, in particular, expression of IL-8 (14.5-fold) and CCL2 (25.5-fold), as assessed by a Luminex assay. The cytokine subsets regulated by Wnt5a overlap partially with those induced by TNF-α. However, no TNF-α and IL-1β was detected after Wnt5a treatment. We then found that Wnt5a alone and the supernatants of Wnt5a-treated HDPCs significantly increased macrophage migration, which supports a role for Wnt5a in macrophage recruitment and as an inflammatory mediator in human dental pulp inflammation. Finally, Wnt5a participates in dental pulp inflammation in a MAPK-dependent (p38-, JNK-, and ERK-dependent) and NF-κB-dependent manner. Our data suggest that Wnt5a, as an inflammatory mediator that drives the integration of cytokines and chemokines, acts downstream of TNF-α. PMID:24891513

Hematopoietic Stem Cells as a Novel Source of Dental Tissue Cells.

PubMed

Wilson, Katie R; Kang, In-Hong; Baliga, Uday; Xiong, Ying; Chatterjee, Shilpak; Moore, Emily; Parthiban, Beneta; Thyagarajan, Krishnamurthy; Borke, James L; Mehrotra, Shikhar; Kirkwood, Keith L; LaRue, Amanda C; Ogawa, Makio; Mehrotra, Meenal

2018-05-23

While earlier studies have suggested that cells positive for hematopoietic markers can be found in dental tissues, it has yet to be confirmed. To conclusively demonstrate this, we utilized a unique transgenic model in which all hematopoietic cells are green fluorescent protein + (GFP + ). Pulp, periodontal ligament (PDL) and alveolar bone (AvB) cell culture analysis demonstrated numerous GFP + cells, which were also CD45 + (indicating hematopoietic origin) and co-expressed markers of cellular populations in pulp (dentin matrix protein-1, dentin sialophosphoprotein, alpha smooth muscle actin [ASMA], osteocalcin), in PDL (periostin, ASMA, vimentin, osteocalcin) and in AvB (Runx-2, bone sialoprotein, alkaline phosphatase, osteocalcin). Transplantation of clonal population derived from a single GFP + hematopoietic stem cell (HSC), into lethally irradiated recipient mice, demonstrated numerous GFP + cells within dental tissues of recipient mice, which also stained for markers of cell populations in pulp, PDL and AvB (used above), indicating that transplanted HSCs can differentiate into cells in dental tissues. These hematopoietic-derived cells deposited collagen and can differentiate in osteogenic media, indicating that they are functional. Thus, our studies demonstrate, for the first time, that cells in pulp, PDL and AvB can have a hematopoietic origin, thereby opening new avenues of therapy for dental diseases and injuries.

Scaffold-free Prevascularized Microtissue Spheroids for Pulp Regeneration

PubMed Central

Dissanayaka, W.L.; Zhu, L.; Hargreaves, K.M.; Jin, L.; Zhang, C.

2014-01-01

Creating an optimal microenvironment that mimics the extracellular matrix (ECM) of natural pulp and securing an adequate blood supply for the survival of cell transplants are major hurdles that need to be overcome in dental pulp regeneration. However, many currently available scaffolds fail to mimic essential functions of natural ECM. The present study investigated a novel approach involving the use of scaffold-free microtissue spheroids of dental pulp stem cells (DPSCs) prevascularized by human umbilical vein endothelial cells (HUVECs) in pulp regeneration. In vitro-fabricated microtissue spheroids were inserted into the canal space of tooth-root slices and were implanted subcutaneously into immunodeficient mice. Histological examination revealed that, after four-week implantation, tooth-root slices containing microtissue spheroids resulted in well-vascularized and cellular pulp-like tissues, compared with empty tooth-root slices, which were filled with only subcutaneous fat tissue. Immunohistochemical staining indicated that the tissue found in the tooth-root slices was of human origin, as characterized by the expression of human mitochondria, and contained odontoblast-like cells organized along the dentin, as assessed by immunostaining for nestin and dentin sialoprotein (DSP). Vascular structures formed by HUVECs in vitro were successfully anastomosed with the host vasculature upon transplantation in vivo, as shown by immunostaining for human CD31. Collectively, these findings demonstrate that prevascularized, scaffold-free, microtissue spheroids can successfully regenerate vascular dental pulp-like tissue and also highlight the significance of the microtissue microenvironment as an optimal environment for successful pulp-regeneration strategies. PMID:25201919

Life cycles of traumatized teeth: long-term observations from a cohort of dental trauma victims.

PubMed

Heithersay, G S

2016-03-01

Life cycles of dental trauma victims can provide important clinical information, especially when viewed over many years. In this first series of life cycles, the pulp and periodontal responses to traumatic injuries of four patients are documented over periods varying from 26 to 51 years. The dynamics of pulp survival following an intrusive luxation and two avulsions are followed, with particular reference to pulp canal calcification to which a new term, root canal stenosis, has been proposed. The life cycles include the successful management of inflammatory root resorption in a replanted tooth with an open apex contrasting with the early prophylactic endodontic treatment of two replanted teeth in a patient with mature apices. The long-term development of invasive cervical resorption in one of the patient's life cycle highlights the importance of ongoing follow-up examinations for dental trauma victims. © 2016 Australian Dental Association.

Dental pulp stem cells. Biology and use for periodontal tissue engineering.

PubMed

Ashri, Nahid Y; Ajlan, Sumaiah A; Aldahmash, Abdullah M

2015-12-01

Inflammatory periodontal disease is a major cause of loss of tooth-supporting structures. Novel approaches for regeneration of periodontal apparatus is an area of intensive research. Periodontal tissue engineering implies the use of appropriate regenerative cells, delivered through a suitable scaffold, and guided through signaling molecules. Dental pulp stem cells have been used in an increasing number of studies in dental tissue engineering. Those cells show mesenchymal (stromal) stem cell-like properties including self-renewal and multilineage differentiation potentials, aside from their relative accessibility and pleasant handling properties. The purpose of this article is to review the biological principles of periodontal tissue engineering, along with the challenges facing the development of a consistent and clinically relevant tissue regeneration platform. This article includes an updated review on dental pulp stem cells and their applications in periodontal regeneration, in combination with different scaffolds and growth factors.

Transforming growth factor beta 1 increases collagen content, and stimulates procollagen I and tissue inhibitor of metalloproteinase-1 production of dental pulp cells: Role of MEK/ERK and activin receptor-like kinase-5/Smad signaling.

PubMed

Lin, Po-Shuen; Chang, Hsiao-Hua; Yeh, Chien-Yang; Chang, Mei-Chi; Chan, Chiu-Po; Kuo, Han-Yueh; Liu, Hsin-Cheng; Liao, Wan-Chuen; Jeng, Po-Yuan; Yeung, Sin-Yuet; Jeng, Jiiang-Huei

2017-05-01

In order to clarify the role of transforming growth factor beta 1 (TGF-β1) in pulp repair/regeneration responses, we investigated the differential signaling pathways responsible for the effects of TGF-β1 on collagen turnover, matrix metalloproteinase-3 (MMP-3), and tissue inhibitor of metalloproteinase-1 (TIMP-1) production in human dental pulp cells. Pulp cells were exposed to TGF-β1 with/without pretreatment and coincubation by 1,4-diamino-2,3-dicyano-1,4-bis(o-aminophenyl mercapto)butadiene (U0126; a mitogen-activated protein kinase kinase [MEK]/extracellular signal-regulated kinase [ERK] inhibitor) and 4-(5-benzol[1,3]dioxol-5-yl-4-pyrldin-2-yl-1H- imidazol-2-yl)-benzamide hydrate (SB431542; an activin receptor-like kinase-5/Smad signaling inhibitor). Sircol collagen assay was used to measure cellular collagen content. Culture medium procollagen I, TIMP-1, and MMP-3 levels were determined by enzyme-linked immunosorbent assay. TGF-β1 increased the collagen content, procollagen I, and TIMP-1 production, but slightly decreased MMP-3 production of pulp cells. SB431542 and U0126 prevented the TGF-β1-induced increase of collagen content and TIMP-1 production of dental pulp cells. These results indicate that TGF-β1 may be involved in the healing/regeneration processes of dental pulp in response to injury by stimulation of collagen and TIMP-1 production. These events are associated with activin receptor-like kinase-5/Smad2/3 and MEK/ERK signaling. Copyright © 2016. Published by Elsevier B.V.

Effect of low-level laser therapy (λ780 nm) on the mechanically damaged dentin-pulp complex in a model of extrusive luxation in rat incisors.

PubMed

de Santana, Dandara Andrade; Fonseca, Gabriela Ferraz; Ramalho, Luciana Maria Pedreira; Rodriguez, Tânia Tavares; Aguiar, Marcio Cajazeira

2017-12-01

In order to regenerate the dental pulp, many strategies have been developed as phototherapy. In the pulp repair, we do not know if gallium-aluminum-arsenide (GaAlAs) laser preserves the primary odontoblasts or stimulates the formation of more dentin matrix when dental pulp is damaged. The aim of the present study was to examine the effect of laser phototherapy (λ780 nm) on vascularization, inflammation, density of the primary odontoblast layer, and formation of reactionary and reparative dentin in the dental pulp by provoking extrusion of the rat incisor. The upper incisors were extruded 3 mm and then repositioned into their original sockets followed by a laser irradiation of the palatal mucosa (λ = 780 nm; p = 70 mW; CW; 4.2 J/cm 2 ; 60 s) every 48 h. Non-traumatized and/or non-irradiated incisors were used as the controls. At 8 and 30 days after surgery, incisors were processed for histological and histomorphometric analysis. Morphological analysis revealed no differences in vascularization between groups, but showed discrete inflammation in some non-irradiated and injured specimens, which correlated with a more irregular reparative dentin. The density of primary odontoblasts in the groups treated with lasers was higher when compared to non-irradiated groups, but no statistically significant difference between groups (p > 0.05). The thickness of the tertiary dentin was increased in both traumatized groups with no statistically significant difference between non-irradiated and irradiated groups (p > 0.05).The present findings revealed that the GaAlAs laser induced small changes on dentin-pulp complex, with more regular dentin matrix in the irradiated dental pulps.

CD146 positive human dental pulp stem cells promote regeneration of dentin/pulp-like structures.

PubMed

Matsui, Mikiko; Kobayashi, Tomoko; Tsutsui, Takeo W

2018-04-01

CD146 and STRO-1 are endothelial biomarkers that are co-expressed on the cellular membranes of blood vessels within human dental pulp tissue. This study characterized the percentage of dentin-like structures produced by CD146-positive (CD146 + ) human dental pulp stem cells (DPSCs), compared with their CD146-negative (CD146 - ) counterparts. DPSC populations were enriched using magnetic-activated cell sorting (MACS), yielding CD146 + and CD146 - cells, as well as mixtures composed of 25% CD146 + cells and 75% CD146 - cells (CD146 +/- ). Cell growth assays indicated that CD146 + cells exhibit an approximate 3-4 h difference in doubling time, compared with CD146 - cells. Cell cycle distributions were determined by flow cytometry analysis. The low percentage of CD146 + cells' DNA content in G 0 /G 1 phase were compared with CD146 - and non-separated cells. In contrast to CD146 - and non-separated cells, prompt mineralization was observed in CD146 + cells. Subsequently, qRT-PCR revealed high mRNA expression of CD146 and Alkaline phosphatase in mineralization-induced CD146 + cells. CD146 + cells were also observed high adipogenic ability by Oil red O staining. Histological examinations revealed an increased area of dentin/pulp-like structures in transplanted CD146 + cells, compared with CD146 - and CD146 +/- cells. Immunohistochemical studies detected dentin matrix protein-1 (DMP1) and dentin sialophosphoprotein (DSPP), as well as human mitochondria, in transplanted DPSCs. Co-expression of CD146 and GFP indicated that CD146 was expressed in transplanted CD146 + cells. CD146 + cells may promote mineralization and generate dentin/pulp-like structures, suggesting a role in self-renewal of stem cells and dental pulp regenerative therapy.

Advanced Scaffolds for Dental Pulp and Periodontal Regeneration.

PubMed

Bottino, Marco C; Pankajakshan, Divya; Nör, Jacques E

2017-10-01

No current therapy promotes root canal disinfection and regeneration of the pulp-dentin complex in cases of pulp necrosis. Antibiotic pastes used to eradicate canal infection negatively affect stem cell survival. Three-dimensional easy-to-fit antibiotic-eluting nanofibers, combined with injectable scaffolds, enriched or not with stem cells and/or growth factors, may increase the likelihood of achieving predictable dental pulp regeneration. Periodontitis is an aggressive disease that impairs the integrity of tooth-supporting structures and may lead to tooth loss. The latest advances in membrane biomodification to endow needed functionalities and technologies to engineer patient-specific membranes/constructs to amplify periodontal regeneration are presented. Copyright © 2017 Elsevier Inc. All rights reserved.

Characterization of mesenchymal stem cells from human dental pulp, preapical follicle and periodontal ligament.

PubMed

Navabazam, Ali Reza; Sadeghian Nodoshan, Fatemeh; Sheikhha, Mohammad Hasan; Miresmaeili, Sayyed Mohsen; Soleimani, Mehrdad; Fesahat, Farzaneh

2013-03-01

Human dental stem cells have high proliferative potential for self-renewal that is important to the regenerative capacity of the tissue. Objective : The aim was to isolate human dental pulp stem cells (DPSC), periodontal ligament stem cells (PDLSC) and periapical follicle stem cells (PAFSC) for their potential role in tissue regeneration. In this experimental study, the postnatal stem cells were isolated from dental pulp, preapical follicle and periodontal ligament .The cells were stained for different stem cell markers by immunocytochemistry. To investigate the mesenchymal nature of cells, differentiation potential along osteoblastic and adipogenic lineages and gene expression profile were performed. For proliferation potential assay, Brdu staining and growth curve tests were performed. Finally, all three cell types were compared together regarding their proliferation, differentiation and displaying phenotype. The isolated cell populations have similar fibroblastic like morphology and expressed all examined cell surface molecule markers. These cells were capable of differentiating into osteocyte with different capability and adipocyte with the same rate. PAFSCs showed more significant proliferation rate than others. Reverse transcriptase PCR (RT-PCR) for nanog, oct4, Alkaline phosphatase (ALP) and glyceraldehydes-3-phosphate dehydrogenease (GADPH) as control gene showed strong positive expression of these genes in all three isolated cell types. PDLSCs, DPSCs and PAFSCs exist in various tissues of the teeth and can use as a source of mesenchymal stem cells for developing bioengineered organs and also in craniomaxillofacial reconstruction with varying efficiency in differentiation and proliferation.

Diabetes mellitus and inflammatory pulpal and periapical disease: a review.

PubMed

Lima, S M F; Grisi, D C; Kogawa, E M; Franco, O L; Peixoto, V C; Gonçalves-Júnior, J F; Arruda, M P; Rezende, T M B

2013-08-01

Diabetes mellitus (DM) is one of the most common metabolic disorders. DM is characterized by hyperglycaemia, resulting in wound healing difficulties and systemic and oral manifestations, which have a direct effect on dental pulp integrity. Experimental and clinical studies have demonstrated a higher prevalence of periapical lesions in patients with uncontrolled diabetes. The influence of DM on periapical bone resorption and its impact on dental intervention of such patients are reviewed, and its aetiology and pathogenesis are analysed at molecular level. Pulps from patients with diabetes have the tendency to present limited dental collateral circulation, impaired immune response, increased risk of acquiring pulp infection (especially anaerobic ones) or necrosis, besides toothache and occasional tendency towards pulp necrosis caused by ischaemia. In regard to molecular pathology, hyperglycaemia is a stimulus for bone resorption, inhibiting osteoblastic differentiation and reducing bone recovery. The relationship between poorly controlled diabetes and bone metabolism is not clearly understood. Molecular knowledge about pulp alterations in patients with diabetes could offer new therapeutic directions. Knowledge about how diabetes affects systemic and oral health has an enduring importance, because it may imply not only systemic complications but also a higher risk of oral diseases with a significant effect on pulp and periapical tissue. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Proteomic Analysis of Mesenchymal Stem Cells from Normal and Deep Carious Dental Pulp

PubMed Central

Gao, Jie; Yan, Wenjuan; Liu, Ying; Xu, Shuaimei; Wu, Buling

2014-01-01

Dental pulp stem cells (DPSCs), precursor cells of odontoblasts, are ideal seed cells for tooth tissue engineering and regeneration. Our previous study has demonstrated that stem cells exist in dental pulp with deep caries and are called carious dental pulp stem cells (CDPSCs). The results indicated that CDPSCs had a higher proliferative and stronger osteogenic differentiation potential than DPSCs. However, the molecular mechanisms responsible for the biological differences between DPSCs and CDPSCs are poorly understood. The aim of this study was to define the molecular features of DPSCs and CDPSCs by comparing the proteomic profiles using two-dimensional fluorescence difference gel electrophoresis (2-D DIGE) in combination with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Our results revealed that there were 18 protein spots differentially expressed between DPSCs and CDPSCs in a narrow pH range of 4 to 7. These differently expressed proteins are mostly involved in the regulation of cell proliferation, differentiation, cell cytoskeleton and motility. In addition, our results suggested that CDPSCs had a higher expression of antioxidative proteins that might protect CDPSCs from oxidative stress. This study explores some potential proteins responsible for the biological differences between DPSCs and CDPSCs and expands our understanding on the molecular mechanisms of mineralization of DPSCs in the formation of the dentin-pulp complex. PMID:24809979

Stem cell regulatory gene expression in human adult dental pulp and periodontal ligament cells undergoing odontogenic/osteogenic differentiation.

PubMed

Liu, Lu; Ling, Junqi; Wei, Xi; Wu, Liping; Xiao, Yin

2009-10-01

During development and regeneration, odontogenesis and osteogenesis are initiated by a cascade of signals driven by several master regulatory genes. In this study, we investigated the differential expression of 84 stem cell-related genes in dental pulp cells (DPCs) and periodontal ligament cells (PDLCs) undergoing odontogenic/osteogenic differentiation. Our results showed that, although there was considerable overlap, certain genes had more differential expression in PDLCs than in DPCs. CCND2, DLL1, and MME were the major upregulated genes in both PDLCs and DPCs, whereas KRT15 was the only gene significantly downregulated in PDLCs and DPCs in both odontogenic and osteogenic differentiation. Interestingly, a large number of regulatory genes in odontogenic and osteogenic differentiation interact or crosstalk via Notch, Wnt, transforming growth factor beta (TGF-beta)/bone morphogenic protein (BMP), and cadherin signaling pathways, such as the regulation of APC, DLL1, CCND2, BMP2, and CDH1. Using a rat dental pulp and periodontal defect model, the expression and distribution of both BMP2 and CDH1 have been verified for their spatial localization in dental pulp and periodontal tissue regeneration. This study has generated an overview of stem cell-related gene expression in DPCs and PDLCs during odontogenic/osteogenic differentiation and revealed that these genes may interact through the Notch, Wnt, TGF-beta/BMP, and cadherin signaling pathways to play a crucial role in determining the fate of dental derived cell and dental tissue regeneration. These findings provided a new insight into the molecular mechanisms of the dental tissue mineralization and regeneration.

Insulin-like growth factor 1 promotes the proliferation and committed differentiation of human dental pulp stem cells through MAPK pathways.

PubMed

Lv, Taohong; Wu, Yongzheng; Mu, Chao; Liu, Genxia; Yan, Ming; Xu, Xiangqin; Wu, Huayin; Du, Jinyin; Yu, Jinhua; Mu, Jinquan

2016-12-01

Insulin-like growth factor 1 (IGF-1) is a broad-spectrum growth-promoting factor that plays a key role in natural tooth development. Human dental pulp stem cells (hDPSCs) are multipotent and can influence the reparative regeneration of dental pulp and dentin. This study was designed to evaluate the effects of IGF-1 on the proliferation and differentiation of human dental pulp stem cells. HDPSCs were isolated and purified from human dental pulps. The proliferation and osteo/odontogenic differentiation of hDPSCs treated with 100ng/ml exogenous IGF-1 were subsequently investigated. MTT assays revealed that IGF-1 enhanced the proliferation of hDPSCs. ALP activity in IGF-1-treated group was obviously enhanced compared to the control group from days 3 to 9. Alizarin red staining revealed that the IGF-1-treated cells contained a greater number of mineralization nodules and had higher calcium concentrations. Moreover, western blot and qRT-PCR analyses demonstrated that the expression levels of several osteogenic genes (e.g., RUNX2, OSX, and OCN) and an odontoblast-specific marker (DSPP) were significantly up-regulated in IGF-1-treated hDPSCs as compared with untreated cells (P<0.01). Interestingly, the expression of phospho-ERK and phospho-p38 were also up-regulated, indicating that the MAPK signaling pathway is activated during the differentiation of hDPSCs. IGF-1 can promote the proliferation and osteo/odontogenic differentiation of hDPSCs by activating MAPK pathways. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of ITGA5 down-regulation on the migration capacity of human dental pulp stem cells

PubMed Central

Xu, Shuaimei; Cui, Li; Ma, Dandan; Sun, Wenjuan; Wu, Buling

2015-01-01

Background: The purpose of this study was to evaluate the role of integrin-α5 (ITGA5) in regulating the migration capacity of human dental pulp stem cells (hDPSCs), which might provide new evidence for understanding the repair and regeneration mechanisms of dental pulp tissues. Materials and methods: The enzyme digestion method was employed to isolate the hDPSCs from dental pulp tissues. The cell surface markers of hDPSCs were detected using flow cytometry analysis. Then the colony forming and multi-differentiation capacity of hDPSCs were evaluated. The lentivirus vector that carried the ITGA5 shRNA was constructed and real-time PCR was used to examine the effectiveness of ITGA5 shRNA lentivirus. Then transwell assay was performed to evaluate the impact of ITGA5 inhibition on the migration capability of hDPSCs. Results: Our results showed that the cells we isolated from the dental pulps were positive for mesenchymal stem cells biomarkers. In addition, the cells possessed both colony forming capacity and multi-differentiation potential. ITGA5 shRNA lentivirus could not only infect hDPSCs with high efficiency, but also down-regulate the expression level of ITGA5 mRNA significantly (P<0.01). The transwell assay revealed the number of cells that migrated to the lower chamber was significantly less in the ITGA5 shRNA group compared with that in the scrambled shRNA group (P=0.016). Conclusion: ITGA5 plays an important role in maintaining and regulating the normal migration capacity of hDPSCs. PMID:26823759

Effects of washed platelets vs platelet-rich plasma on the proliferation and mineralization of rat dental pulp cells.

PubMed

Zhang, L; Xie, Y H; Lin, B R

2015-08-14

We examined the effects of washed platelets (WPLTs) and platelet-rich plasma (PRP) on the proliferation and mineralization of rat dental pulp cells. Rat dental pulp cells were separated, cultured, and identified. Medium containing 1, 10, 100, or 500 mL/L PRP or WPLTs was added to 4th generation cells. The MTS method was used to determine cell proliferation. Alizarin red staining was used to observe the formation of mineralized nodules after cell mineralization and induction for 10 and 20 days under different culture conditions, and the areas of the mineralized nodules formed 20 days after induction were computed. The addition of 1, 10, and 100 mL/L WPLTs or PRP significantly promoted rat dental pulp cell proliferation (P < 0.05) whereas 500 mL/L WPLTs or PRP had no significant effect (P > 0.05). Under the same concentrations, no significant differences on cell proliferation were observed between WPLT and PRP treatments (P > 0.05 in all groups). After 10 days mineralization and culture, the 100 and 500 mL/L WPLT and PRP group positive nodule rates were significantly higher than those of the low concentration and the control groups (P < 0.05). After 20 days, the areas of the mineralized nodules formed in the 100 and 500 mL/L WPLT and PRP groups were significantly larger than those in the control group (P < 0.05). These results demonstrate that both WPLTs and PRP are equally able to significantly promote the proliferation and calcification of rat dental pulp cells under a certain range of concentrations.

Noxious stimuli do not determine reflex cardiorespiratory effects in anesthetized rabbits.

PubMed

Raimondi, G; Legramante, J M; Iellamo, F; Frisardi, G; Cassarino, S; Peruzzi, G

1996-12-01

The main purpose of this study is to examine whether the stimulation of an exclusively pain-sensing receptive field (dental pulp) could determine cardiorespiratory effects in animals in which the cortical integration of the peripheral information is abolished by deep anesthesia. In 15 anesthetized (alpha-chloralose and urethan) rabbits, low (3-Hz)- and high-frequency (100-Hz) electrical dental pulp stimulation was performed. Because this stimulation caused dynamic and static reflex contractions of the digastric muscles leading to jaw opening jaw-opening reflex (JOR); an indirect sign of algoceptive fiber activation], experimentally induced direct dynamic and static contractions of the digastric muscle were also performed. The low- and high-frequency stimulation of the dental pulp determined cardiovascular [systolic arterial pressure (SAP): -21.7 +/- 4.6 and 10.8 +/- 4.7 mmHg, respectively] and respiratory [pulmonary ventilation (VE): 145.1 +/- 44.9 and 109.3 +/- 28.4 ml/min, respectively] reflex responses similar to those observed during experimentally induced dynamic (SAP: -17.5 +/- 4.2 mmHg; VE: 228.0 +/- 58.5 ml/min) and static (SAP: 5.8 +/- 1.5 mmHg; VE: 148.0 +/- 75.3 ml/min) muscular contractions. The elimination of digastric muscular contraction (JOR) obtained by muscular paralysis did away with the cardiovascular changes induced by dental pulp stimulation, the effectiveness of which in stimulating dental pulp receptors has been shown by recording trigeminal-evoked potentials in six additional rabbits. The main conclusion was that, in deeply anesthetized animals, an algesic stimulus is unable to determine cardiorespiratory effects, which appear to be exclusively linked to the stimulation of ergoreceptors induced by muscular contraction.

The effect of dentinal fluid flow during loading in various directions--simulation of fluid-structure interaction.

PubMed

Su, Kuo-Chih; Chang, Chih-Han; Chuang, Shu-Fen; Ng, Eddie Yin-Kwee

2013-06-01

This study uses a fluid-structure interaction (FSI) simulation to evaluate the fluid flow in a dental intrapulpal chamber induced by the deformation of the tooth structure during loading in various directions. The FSI is used for the biomechanics simulation of dental intrapulpal responses with the force loading gradually increasing from 0 to 100N at 0°, 30°, 45°, 60°, and 90° on the tooth surface in 1s, respectively. The effect of stress or deformation on tooth and fluid flow changes in the pulp chamber are evaluated. A horizontal loading force on a tooth may induce tooth structure deformation, which increases fluid flow velocity in the coronal pulp. Thus, horizontal loading on a tooth may easily induce tooth pain. This study suggests that experiments to investigate the relationship between loading in various directions and dental pain should avoid measuring the bulk pulpal fluid flow from radicular pulp, but rather should measure the dentinal fluid flow in the dentinal tubules or coronal pulp. The FSI analysis used here could provide a powerful tool for investigating problems with coupled solid and fluid structures in dental biomechanics. Copyright © 2012 Elsevier Ltd. All rights reserved.

Tissue non-specific alkaline phosphatase production by human dental pulp stromal cells is enhanced by high density cell culture.

PubMed

Tomlinson, Matthew J; Dennis, Caitriona; Yang, Xuebin B; Kirkham, Jennifer

2015-08-01

The cell surface hydrolase tissue non-specific alkaline phosphatase (TNAP) (also known as MSCA-1) is used to identify a sub-population of bone marrow stromal cells (BMSCs) with high mineralising potential and is found on subsets of cells within the dental pulp. We aim to determine whether TNAP is co-expressed by human dental pulp stromal cells (hDPSCs) alongside a range of BMSC markers, whether this is an active form of the enzyme and the effects of culture duration and cell density on its expression. Cells from primary dental pulp and culture expanded hDPSCs expressed TNAP. Subsequent analyses revealed persistent TNAP expression and co-expression with BMSC markers such as CD73 and CD90. Flow cytometry and biochemical assays showed that increased culture durations and cell densities enhanced TNAP expression by hDPSCs. Arresting the hDPSC cell cycle also increased TNAP expression. These data confirm that TNAP is co-expressed by hDPSCs together with other BMSC markers and show that cell density affects TNAP expression levels. We conclude that TNAP is a potentially useful marker for hDPSC selection especially for uses in mineralised tissue regenerative therapies.

Dentin and pulp sense cold stimulus.

PubMed

Tokuda, Masayuki; Tatsuyama, Shoko; Fujisawa, Mari; Morimoto-Yamashita, Yoko; Kawakami, Yoshiko; Shibukawa, Yoshiyuki; Torii, Mistuso

2015-05-01

Dentin hypersensitivity is a common symptom, and recent convergent evidences have reported transient receptor potential (TRP) channels in odontoblasts act as mechanical and thermal molecular sensor, which detect stimulation applied on the exposed dentin surface, to drive multiple odontoblastic cellular functions, such as sensory transduction and/or dentin formation. In the present study, we confirmed expression of TRP melastatin subfamily member-8 (TRPM8) channels in primary cultured cells derived from human dental pulp cells (HPCs) and mouse odontoblast-lineage cells (OLCs) as well as in dentin matrix protein-1 (DMP-1) and dentin sialoprotein (DSP) positive acutely isolated rat odontoblasts from dental pulp tissue slice culture by immunohistochemical analyses. In addition, we detected TRPM8 channel expression on HPCs and OLCs by RT-PCR and Western blotting analyses. These results indicated that both odontoblasts and dental pulp cells express TRPM8 channels in rat, mouse and human, and therefore we hypothesize they may contribute as cold sensor in tooth. Copyright © 2015 Elsevier Ltd. All rights reserved.

Mineralization and Expression of Col1a1-3.6GFP Transgene in Primary Dental Pulp Culture

PubMed Central

Balic, Anamaria; Rodgers, Barbara; Mina, Mina

2008-01-01

We have examined and compared the effects of various differentiation-inducing media on mineralization, cell morphology and expression of pOBCol3.6GFP (3.6-GFP) in primary dental pulp cultures derived from 3.6-GFP transgenic mice. Our results show that media containing ascorbic acid only could not induce mineralization in primary dental pulp cultures. On the other hand, media containing ascorbic acid and β-glycerophosphate induced formation of mineralized matrix-containing dentin. The amount of mineralized matrix was increased by addition of dexamethasone. Cells treated with ascorbic acid and β-glycerophosphate were fibroblast like and cells treated with dexamethasone were cuboidal. In all culture conditions, high levels of 3.6-GFP were expressed in areas of mineralization PMID:18781059

Dental pulp stem cells express tendon markers under mechanical loading and are a potential cell source for tissue engineering of tendon-like tissue.

PubMed

Chen, Yu-Ying; He, Sheng-Teng; Yan, Fu-Hua; Zhou, Peng-Fei; Luo, Kai; Zhang, Yan-Ding; Xiao, Yin; Lin, Min-Kui

2016-12-16

Postnatal mesenchymal stem cells have the capacity to differentiate into multiple cell lineages. This study explored the possibility of dental pulp stem cells (DPSCs) for potential application in tendon tissue engineering. The expression of tendon-related markers such as scleraxis, tenascin-C, tenomodulin, eye absent homologue 2, collagens I and VI was detected in dental pulp tissue. Interestingly, under mechanical stimulation, these tendon-related markers were significantly enhanced when DPSCs were seeded in aligned polyglycolic acid (PGA) fibre scaffolds. Furthermore, mature tendon-like tissue was formed after transplantation of DPSC-PGA constructs under mechanical loading conditions in a mouse model. This study demonstrates that DPSCs could be a potential stem cell source for tissue engineering of tendon-like tissue.

The effects of human platelet lysate on dental pulp stem cells derived from impacted human third molars.

PubMed

Chen, Bo; Sun, Hai-Hua; Wang, Han-Guo; Kong, Hui; Chen, Fa-Ming; Yu, Qing

2012-07-01

Human platelet lysate (PL) has been suggested as a substitute for fetal bovine serum (FBS) in the large-scale expansion of dental pulp stem cells (DPSCs). However, the biological effects and the optimal concentrations of PL for the proliferation and differentiation of human DPSCs remain unexplored. We isolated and expanded stem cells from the dental pulp of extracted third molars and evaluated the effects of PL on the cells' proliferative capacity and differentiation potential in vitro and in vivo. Before testing, immunocytochemical staining and flow cytometry-based cell sorting showed that the cells derived from human dental pulp contained mesenchymal stem cell populations. Cells were grown on tissue culture plastic or on hydroxyapatite-tricalcium phosphate (HA/TCP) biomaterials and were incubated with either normal or odontogenic/osteogenic media in the presence or absence of various concentrations of human PL for further investigation. The proliferation of DPSCs was significantly increased when the cells were cultured in 5% PL under all testing conditions (P < 0.05). However, this enhancement was inconsistent when the cells were cultured in 1% PL or in 10% PL; 10% PL significantly inhibited cell proliferation and was therefore excluded from further differentiation testing. Culture medium containing 5% PL also significantly promoted the mineralized differentiation of DPSCs, as indicated by the measurement of alkaline phosphatase activity and calcium deposition under mineral-conditioned media (P < 0.05). Scanning electron microscopy and modified Ponceau trichrome staining showed that the cells treated with 5% PL and mineralizing media were highly capable of integrating with the HA/TCP biomaterials and had fully covered the surface of the scaffold with an extensive sheet-like structure 14 d after seeding. In addition, 5% PL showed significantly positive effects on tissue regeneration in two in vivo transplantation models. We conclude that the appropriate concentration of PL enhances the proliferation and mineralized differentiation of human DPSCs both in vitro and in vivo, which supports the use of PL as an alternative to FBS or a nonzoonotic adjuvant for cell culture in future clinical trials. However, the elucidation of the molecular complexity of PL products and the identification of both the essential growth factors that determine the fate of a specific stem cell and the criteria to establish dosing require further investigation. Copyright © 2012 Elsevier Ltd. All rights reserved.

Prostaglandin E2 to diagnose between reversible and irreversible pulpitis.

PubMed

Petrini, M; Ferrante, M; Ciavarelli, L; Brunetti, L; Vacca, M; Spoto, G

2012-01-01

The aim of this work is to verify a correlation between the grade of inflammation and the concentration of PGE2 in human dental pulp. A total of 25 human dental pulps were examined by histological analysis and radioimmunologic dosage of PGE2. The pulps used in this experiment were from healthy and symptomatic teeth; the first ones were collected from teeth destined to be extracted for orthodontic reasons. An increase was observed of PGE2 in reversible pulpitis compared with healthy pulps and with the irreversible pulpitis and the clear decrease of these when NSAIDs are taken. This study demonstrates that PGE2 level is correlated to histological analysis thus allowing to distinguish symptomatic teeth in reversible and irreversible pulpitis.

Vital Pulp Therapy of a Mature Molar with Concurrent Hyperplastic Pulpitis, Internal Root Resorption and Periradicular Periodontitis: A Case Report

PubMed Central

Asgary, Saeed; Kemal Çalışkan, Mehmet

2015-01-01

Vital pulp therapy (VPT) of permanent mature teeth is continuously ascertaining to be a more reliable endodontic treatment. The purpose of this case report was to describe successful VPT of a mature mandibular left first molar with concurrent hyperplastic pulpitis, internal root resorption and periradicular periodontitis in a 35-year-old male patient. After complete caries removal and access cavity preparation, the dental pulp was removed from the coronal third of the roots. To protect the remaining pulp, calcium-enriched mixture (CEM) cement was placed and adapted into the cavities; the tooth was then restored with amalgam. Six months after VPT, radiographic examination showed evidence of periradicular healing. Clinically, the tooth was functional without signs and symptoms of infection/inflammation. The successful outcome of this case suggests that diseased dental pulp (i.e. irreversible pulpitis) has the potential to heal after pulp protection with CEM biocement. PMID:26523145

Temperature changes in the pulp chamber during dentin ablation with Er:YAG laser

NASA Astrophysics Data System (ADS)

Zhang, Xianzeng; Zhao, Haibin; Zhan, Zhenlin; Guo, Wenqing; Xie, Shusen

2012-12-01

To examine the temperature changes in the pulp chamber during cavity preparation in dentin with the Er:YAG laser (2940 nm), a total 20 intact premolars teeth were divided into 4 groups for dentin ablation with different radiant exposures at 4Hz and 8Hz with and without water spray. A K-type thermocouple was used to monitor the temperature changes in pulp chamber during laser treatment. The total time of irradiation was 70 sec. the water spray rate was 3 mL/min. It showed that maximum temperature rise increases with the increasing of radiant exposure and pulse repetition rate and the additional water cooling during laser ablation can significantly reduce the temperature rise in pulp chamber which will benefit to avoid or reduce thermal damage to tooth structure and dental pulp. The highest rise of temperature in the pulp was achieved with 20 J/cm2 and 8 Hz (19.83°C ). For all sample without water spray, the rise of temperature was exceed 5 °C . In contrast, with water spray, the temperature rise in the pulp can be firmly controlled under 1°C. The results also indicated that ablation rate and efficiency can be enhanced by increasing the incident radiant exposure and pulse repetition rate, which simultaneously producing more heat accumulation in dental tissue and causing thermal damage to dental tissue. By applying an additional water spray, thermal damage can be significantly reduced in clinical application.

Characteristics of dental pulp in human upper first premolar teeth based on immunohistochemical and morphometric examinations.

PubMed

Tomaszewska, Joanna Maria; Miskowiak, Bogdan; Matthews-Brzozowska, Teresa; Wierzbicki, Piotr

2013-01-01

Teeth extracted for orthodontic reasons are commonly considered as healthy. Therefore, it is possible to examine structure of the dental pulp can be fully recognized and how it is affected by malocclusion. The aim of the study was to evaluate by immunohistochemistry (IHC) and morphometry dental pulp in human upper first premolar teeth extracted for orthodontic reasons. The material comprised 36 teeth of 20 patients in the age range 16-26 years. By the use of IHC markers the presence of immunocompetent cells (CD20, CD45RO, and CD68), blood vessels (CD31) and nerves (PGP9.5) were examined in the pulp. Inflammatory infiltrates and tissue atrophy were observed in 24 and 10 teeth, respectively. Strong positive correlation between the width of the odontoblastic layer, the number of rows of odontoblast nuclei and the increase of MVA (microvessel area) in the pulp of atrophic teeth was found. The cellular infiltrations found in H&E-stained sections were identified by IHC as memory T cells (CD45RO+) and B lymphocytes (CD20+) with macrophages (CD68+) present at the periphery. The CD20 antigen was intensively expressed in 13 teeth, CD45RO in 33 teeth, and CD68 in 20 teeth. Thus, despite the lack of any clinical signs of pulp disease many teeth extracted for orthodontic reasons show focal pulp inflammation and atrophy which probably results from the malocclusion stress accompanying teeth crowding.

Evidence of a louse-borne outbreak involving typhus in Douai, 1710-1712 during the war of Spanish succession.

PubMed

Nguyen-Hieu, Tung; Aboudharam, Gérard; Signoli, Michel; Rigeade, Catherine; Drancourt, Michel; Raoult, Didier

2010-10-27

The new field of paleomicrobiology allows past outbreaks to be identified by testing dental pulp of human remains with PCR. We identified a mass grave in Douai, France dating from the early XVIII(th) century. This city was besieged during the European war of Spanish succession. We tested dental pulp from 1192 teeth (including 40 from Douai) by quantitative PCR (qPCR) for R. prowazekii and B. quintana. We also used ultra-sensitive suicide PCR to detect R. prowazekii and genotyped positive samples. In the Douai remains, we identified one case of B. quintana infection (by qPCR) and R. prowazekii (by suicide PCR) in 6/21 individuals (29%). The R. prowazekii was genotype B, a genotype previously found in a Spanish isolate obtained in the first part of the XX(th) century. Louse-borne outbreaks were raging during the XVIII(th) century; our results support the hypothesis that typhus was imported into Europe by Spanish soldiers from America.

Evidence of a Louse-Borne Outbreak Involving Typhus in Douai, 1710-1712 during the War of Spanish Succession

PubMed Central

Nguyen-Hieu, Tung; Aboudharam, Gérard; Signoli, Michel; Rigeade, Catherine; Drancourt, Michel; Raoult, Didier

2010-01-01

Background The new field of paleomicrobiology allows past outbreaks to be identified by testing dental pulp of human remains with PCR. Methods We identified a mass grave in Douai, France dating from the early XVIIIth century. This city was besieged during the European war of Spanish succession. We tested dental pulp from 1192 teeth (including 40 from Douai) by quantitative PCR (qPCR) for R. prowazekii and B. quintana. We also used ultra-sensitive suicide PCR to detect R. prowazekii and genotyped positive samples. Results and Discussion In the Douai remains, we identified one case of B. quintana infection (by qPCR) and R. prowazekii (by suicide PCR) in 6/21 individuals (29%). The R. prowazekii was genotype B, a genotype previously found in a Spanish isolate obtained in the first part of the XXth century. Conclusion Louse-borne outbreaks were raging during the XVIIIth century; our results support the hypothesis that typhus was imported into Europe by Spanish soldiers from America. PMID:21060879

Behavioral effects of pulp exposure in mice lacking cannabinoid receptor 2.

PubMed

Flake, Natasha M; Zweifel, Larry S

2012-01-01

Cannabinoid receptor 2 (CB2) is an intriguing target for the treatment of pain because of its ability to mediate analgesia without psychoactive effects, but little is known about the role of CB2 in pain of endodontic origin. The purpose of this study was to determine the behavioral effects of dental pulp exposure in wild-type (WT) mice and to explore the contribution of CB2 to these behaviors using CB2 knockout (CB2 KO) mice. Pulp exposures were created unilaterally in the maxillary and mandibular first molars of female WT and CB2 KO mice. The open field test was used before pulp exposure or sham surgery, and postoperatively at 1 day, 1 week, 2 weeks, and 3 weeks. Mouse body weight and food consumption were recorded preoperatively and postoperatively at 1 day, 2 days, and 1 week. At baseline, CB2 KO mice weighed significantly more and had significantly greater food intake than WT mice. CB2 KO mice exhibited greater anxiety-like behavior in the baseline open field test, having significantly fewer center crossings and less distance traveled than WT mice. Pulp exposure had relatively little effect on the behavior of WT mice. CB2 KO mice with pulp exposures showed a decrease in food intake and body weight after surgery, and pulp exposure resulted in significantly fewer center crossings in the open field test in CB2 KO mice. Pulp exposure in CB2 KO mice resulted in behaviors consistent with an increase in pain and/or anxiety. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Up-regulation of IL-23 expression in human dental pulp fibroblasts by IL-17 via activation of the NF-κB and MAPK pathways.

PubMed

Wei, L; Liu, M; Xiong, H; Peng, B

2017-11-06

To investigate the effects of the pro-inflammatory and Th17-polarizing mediator IL-17 on HDPFs-mediated IL-23 production and the molecular mechanism involved. Interleukin (IL)-17R expression was determined by semi-quantitative reverse transcriptase-polymerase chain reaction and Western blot in cultured human dental pulp fibroblasts (HDPFs). Quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay were used to determine IL-23 mRNA and protein levels in IL-17-stimulated HDPFs, respectively. The nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinases (MAPKs) signalling pathways that mediate the IL-17-stimulated production of IL-23 was investigated using Western blot and specific signalling inhibitor analyses. Statistical analyses were performed using Kruskal-Wallis tests followed by the Mann-Whitney U-test. Statistical significance was considered when the P value < 0.05. Primary HDPFs steadily expressed IL-17R mRNA and surface-bound protein. IL-17 stimulated the expression of IL-23 mRNA and protein in cultured human dental pulp fibroblasts, which was attenuated by IL-17 or IL-17R neutralizing antibodies. In accordance with the enhanced expression of IL-23, IL-17 stimulation resulted in rapid activation of p38 MAPK, extracellular signal-regulated kinase (ERK) 1/2, c-Jun-N-terminal kinase (JNK) and NF-κB in HDPFs. Inhibitors of p38 MAPK, ERK 1/2 or NF-κB significantly suppressed, whereas blocking JNK substantially augmented IL-23 production from IL-17-stimulated HDPFs. HDPFs expressed IL-17R and responded to IL-17 to produce IL-23 via the activation of the NF-κB and MAPK signalling pathways. The findings provide insights into the cellular mechanisms of the participation of IL-17 in the activation of HDPFs in inflamed pulp tissue. © 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Odontoblast-Like Cells Differentiated from Dental Pulp Stem Cells Retain Their Phenotype after Subcultivation

PubMed Central

Baldión, Paula A.; Velandia-Romero, Myriam L.

2018-01-01

Odontoblasts, the main cell type in teeth pulp tissue, are not cultivable and they are responsible for the first line of response after dental restauration. Studies on dental materials cytotoxicity and odontoblast cells physiology require large quantity of homogenous cells retaining most of the phenotype characteristics. Odontoblast-like cells (OLC) were differentiated from human dental pulp stem cells using differentiation medium (containing TGF-β1), and OLC expanded after trypsinization (EXP-21) were evaluated and compared. Despite a slower cell growth curve, EXP-21 cells express similarly the odontoblast markers dentinal sialophosphoprotein and dentin matrix protein-1 concomitantly with RUNX2 transcripts and low alkaline phosphatase activity as expected. Both OLC and EXP-21 cells showed similar mineral deposition activity evidenced by alizarin red and von Kossa staining. These results pointed out minor changes in phenotype of subcultured EXP-21 regarding the primarily differentiated OLC, making the subcultivation of these cells a useful strategy to obtain odontoblasts for biocompatibility or cell physiology studies in dentistry. PMID:29670655

Sensitivity of human dental pulp cells to eighteen chemical agents used for endodontic treatments in dentistry.

PubMed

Kobayashi, Morio; Tsutsui, Takeo W; Kobayashi, Tomoko; Ohno, Maki; Higo, Yukari; Inaba, Tomohiro; Tsutsui, Takeki

2013-01-01

To determine the adverse effects against human dental pulp tissue, the sensitivity of human dental pulp cells (D824 cells) to 18 chemical agents used for endodontic treatments in dentistry was examined. The cytotoxicity, as determined by a decrease in colony-forming ability of cells treated with the chemical agents, increased as the concentration increased. As a quantitative measure of the cytotoxic effect, LC(50), the concentration which induces a 50% lethality, was extrapolated from the concentration-response curves. The rank of the chemical agents according to their cytotoxic effect (LC(50)) was sodium arsenite > formaldehyde > hydrogen peroxide > zinc oxide > thymol ≈ iodoform ≈ eugenol > guaiacol > ethylenediaminetetraacetic acid ≈ iodine > procaine > lidocaine ≈ chloramphenicol ≈ m-cresol > calcium hydroxide ≈ sodium hypochlorite ≈ phenol ≈ p-phenolsulfonic acid. To compare the cytotoxicity and the levels of apoptosis and mRNA expression of five genes related to the function of dental pulp tissue, D824 cells treated with the LC(50) concentrations of chemical agents were assayed by the TUNEL method and quantitative reverse transcription polymerase chain reaction analysis, respectively. The inducibility of apoptotic cells and the level of mRNA expression of the genes varied with the chemical agents, indicating that both effects occurred independent of the rank of cytotoxic effect of the chemical agents. The results not only provide information concerning cytotoxicity of various chemical agents to human dental pulp cells, but also show an insight into the diversity of the pharmacodynamic action of the chemical agents.

Dental pulp of the third molar: a new source of pluripotent-like stem cells.

PubMed

Atari, Maher; Gil-Recio, Carlos; Fabregat, Marc; García-Fernández, Dani; Barajas, Miguel; Carrasco, Miguel A; Jung, Han-Sung; Alfaro, F Hernández; Casals, Nuria; Prosper, Felipe; Ferrés-Padró, Eduard; Giner, Luis

2012-07-15

Dental pulp is particularly interesting in regenerative medicine because of the accessibility and differentiation potential of the tissue. Dental pulp has an early developmental origin with multi-lineage differentiation potential as a result of its development during childhood and adolescence. However, no study has previously identified the presence of stem cell populations with embryonic-like phenotypes in human dental pulp from the third molar. In the present work, we describe a new population of dental pulp pluripotent-like stem cells (DPPSCs) that were isolated by culture in medium containing LIF, EGF and PDGF. These cells are SSEA4(+), OCT3/4(+), NANOG(+), SOX2(+), LIN28(+), CD13(+), CD105(+), CD34(-), CD45(-), CD90(+), CD29(+), CD73(+), STRO1(+) and CD146(-), and they show genetic stability in vitro based on genomic analysis with a newly described CGH technique. Interestingly, DPPSCs were able to form both embryoid-body-like structures (EBs) in vitro and teratoma-like structures that contained tissues derived from all three embryonic germ layers when injected in nude mice. We examined the capacity of DPPSCs to differentiate in vitro into tissues that have similar characteristics to mesoderm, endoderm and ectoderm layers in both 2D and 3D cultures. We performed a comparative RT-PCR analysis of GATA4, GATA6, MIXL1, NANOG, OCT3/4, SOX1 and SOX2 to determine the degree of similarity between DPPSCs, EBs and human induced pluripotent stem cells (hIPSCs). Our analysis revealed that DPPSCs, hIPSC and EBs have the same gene expression profile. Because DPPSCs can be derived from healthy human molars from patients of different sexes and ages, they represent an easily accessible source of stem cells, which opens a range of new possibilities for regenerative medicine.

One step pulp revascularization treatment of an immature permanent tooth with chronic apical abscess: a case report.

PubMed

Shin, S Y; Albert, J S; Mortman, R E

2009-12-01

To describe a case in which a mandibular right second premolar with a necrotic pulp, sinus tract, periradicular radiolucency and an immature apex underwent revascularization via a single treatment approach. Revascularization procedures have the potential to heal a partially necrotic pulp, which can be beneficial for the continued root development of immature teeth. However, it is not clear which revascularization protocols are the most effective. This case report details the outcome of a successful revascularization procedure on tooth 45 (FDI) in a 12-year-old patient, eliminating the associated periapical pathosis within 19 months. The tooth was treated using coronal root irrigation with 6% NaOCl and 2% chlorhexidine without instrumentation in a single visit. The successful outcome of this case report suggests that this conservative revascularization treatment approach can preserve the vitality of the dental pulp stem cells and create a suitable environment for pulp regeneration, resulting in the completion of root maturation. The noninstrumentation procedure using 6% NaOCl and 2% chlorhexidine coronal irrigation may help preserve the remaining vital dental pulp stem cells believed to be critical for pulp revascularization. A single visit pulp revascularization protocol can be a favourable treatment option for an immature permanent tooth with a partially necrotic pulp.

Stimulation of angiogenesis, neurogenesis and regeneration by side population cells from dental pulp.

PubMed

Ishizaka, Ryo; Hayashi, Yuki; Iohara, Koichiro; Sugiyama, Masahiko; Murakami, Masashi; Yamamoto, Tsubasa; Fukuta, Osamu; Nakashima, Misako

2013-03-01

Mesenchymal stem cells (MSCs) have been used for cell therapy in various experimental disease models. However, the regenerative potential of MSCs from different tissue sources and the influence of the tissue niche have not been investigated. In this study, we compared the regenerative potential of dental pulp, bone marrow and adipose tissue-derived CD31(-) side population (SP) cells isolated from an individual porcine source. Pulp CD31(-) SP cells expressed the highest levels of angiogenic/neurotrophic factors and had the highest migration activity. Conditioned medium from pulp CD31(-) SP cells produced potent anti-apoptotic activity and neurite outgrowth, compared to those from bone marrow and adipose CD31(-) SP cells. Transplantation of pulp CD31(-) SP cells in a mouse hindlimb ischemia model produced higher blood flow and capillary density than transplantation of bone marrow and adipose CD31(-) SP cells. Motor function recovery and infarct size reduction were greater with pulp CD31(-) SP cells. Pulp CD31(-) SP cells induced maximal angiogenesis, neurogenesis and pulp regeneration in ectopic transplantation models compared to other tissue sources. These results demonstrate that pulp stem cells have higher angiogenic, neurogenic and regenerative potential and may therefore be superior to bone marrow and adipose stem cells for cell therapy. Copyright © 2012 Elsevier Ltd. All rights reserved.

In-vitro transdentinal diffusion of monomers from adhesives.

PubMed

Putzeys, Eveline; Duca, Radu Corneliu; Coppens, Lieve; Vanoirbeek, Jeroen; Godderis, Lode; Van Meerbeek, Bart; Van Landuyt, Kirsten L

2018-06-01

Biocompatibility of adhesives is important since adhesives may be applied on dentin near the pulp. Accurate knowledge of the quantity of monomers reaching the pulp is important to determine potential side effects. The aim of this study was to assess the transdentinal diffusion of residual monomers from dental adhesive systems using an in-vitro pulp chamber model. Dentin disks with a thickness of 300 µm were produced from human third molars. These disks were fixed between two open-ended glass tubes, representing an in-vitro pulp chamber. The etch-and-rinse adhesive OptiBond FL and the self-etch adhesive Clearfil SE Bond were applied to the dentin side of the disks, while on in the pulpal side, the glass tube was filled with 600 µL water. The transdentinal diffusion of different monomers was quantified using ultra-performance liquid chromatography-tandem mass spectrometry. The monomers HEMA, CQ, BisGMA, GPDM, 10-MDP and UDMA eluted from the dental materials and were able to diffuse through the dentin disks to a certain extent. Compounds with a lower molecular weight (uncured group: HEMA 7850 nmol and CQ 78.2 nmol) were more likely to elute and diffuse compared to monomers with a higher molecular weight (uncured group: BisGMA 0.42 nmol). When the adhesives were left uncured, diffusion was up to 10 times higher compared to the cured conditions. This in-vitro research resulted in the quantification of various monomers able to diffuse through dentin and therefore contributes to a more detailed understanding about the potential exposure of the dental pulp to monomers from dental adhesives. Biocompatibility of adhesives is important since adhesives may be applied on dentin near the pulp, where tubular density and diameter are greatest. Copyright © 2018. Published by Elsevier Ltd.

Response of human dental pulp cells to a silver-containing PLGA/TCP-nanofabric as a potential antibacterial regenerative pulp-capping material.

PubMed

Cvikl, Barbara; Hess, Samuel C; Miron, Richard J; Agis, Hermann; Bosshardt, Dieter; Attin, Thomas; Schmidlin, Patrick R; Lussi, Adrian

2017-02-27

Damage or exposure of the dental pulp requires immediate therapeutic intervention. This study assessed the biocompatibility of a silver-containing PLGA/TCP-nanofabric scaffold (PLGA/Ag-TCP) in two in vitro models, i.e. the material adapted on pre-cultured cells and cells directly cultured on the material, respectively. Collagen saffolds with and without hyaluronan acid (Coll-HA; Coll) using both cell culturing methods and cells growing on culture plates served as reference. Cell viability and proliferation were assessed after 24, 48, and 72 h based on formazan formation and BrdU incorporation. Scaffolds were harvested. Gene expression of interleukin(IL)-6, tumor necrosis factor (TNF)-alpha, and alkaline phosphatase (AP) was assessed 24 h after stimulation. In both models formazan formation and BrdU incorporation was reduced by PLGA/Ag-TCP on dental pulp cells, while no significant reduction was found in cells with Coll and Coll-HA. Cells with PLGA/Ag-TCP for 72 h showed similar relative BrdU incorporation than cells stimulated with Coll and Coll-HA. A prominent increase in the pro-inflammatory genes IL-6 and TNF-α was observed when cells were cultured with PLGA/Ag-TCP compared to the other groups. This increase was parallel with a slight increase in AP expression. Overall, no differences between the two culture methods were observed. PLGA/Ag-TCP decreased viability and proliferation rate of human dental pulp cells and increased the pro-inflammatory capacity and alkaline phosphatase expression. Whether these cellular responses observed in vitro translate into pulp regeneration in vivo will be assessed in further studies.

OCT4B1 Regulates the Cellular Stress Response of Human Dental Pulp Cells with Inflammation

PubMed Central

Liu, Lu; Huang, Rong; Yang, Ruiqi

2017-01-01

Introduction. Infection and apoptosis are combined triggers for inflammation in dental tissues. Octamer-binding transcription factor 4-B1 (OCT4B1), a novel spliced variant of OCT4 family, could respond to the cellular stress and possess antiapoptotic property. However, its specific role in dental pulpitis remains unknown. Methods. To investigate the effect of OCT4B1 on inflammation of dental pulp cells (DPCs), its expression in inflamed dental pulp tissues and DPCs was examined by in situ hybridization, real-time PCR, and FISH assay. OCT4B1 overexpressed DPCs model was established, confirmed by western blot and immunofluorescence staining, and then stimulated with Lipopolysaccharide (LPS). Apoptotic rate was determined by Hoechst/PI staining and FACS. Cell survival rate was calculated by CCK8 assay. Results. In situ hybridization, real-time PCR, and FISH assay revealed that OCT4B1 was extensively expressed in inflamed dental pulp tissues and DPCs with LPS stimulation. Western blot and immunofluorescence staining showed the expression of OCT4B1 and OCT4B increased after OCT4B1 transfection. Hoechst/PI staining and FACS demonstrated that less red/blue fluorescence was detected and apoptotic percentage decreased (3.45%) after transfection. CCK8 demonstrated that the survival rate of pCDH-OCT4B1-flag cells increased. Conclusions. OCT4B1 plays an essential role in inflammation and apoptosis of DPCs. OCT4B might operate synergistically with OCT4B1 to reduce apoptosis. PMID:28473980

Histological Effects of Enamel Matrix Derivative on Exposed Dental Pulp.

PubMed

Bajić, Marijana Popović; Danilović, Vesna; Prokić, Branislav; Prokić, Bogomir Bolka; Manojlović, Milica; Živković, Slavoljub

2015-01-01

Direct pulp capping procedure is a therapeutic application of a drug on exposed tooth pulp in order to ensure the closure of the pulp chamber and to allow the healing process to take place. The aim of this study was to examine the histological effects of Emdogain® on exposed tooth pulp of a Vietnamese pig (Sus scrofa verus). The study comprised 20 teeth of a Vietnamese pig. After class V preparation on the buccal surfaces of incisors, canines and first premolars, pulp was exposed. In the experimental group, the perforations were capped with Emdogain® (Straumann, Basel, Switzerland), while in the control group pulp capping was performed with MTA® (Dentsply Tulsa Dental, Johnson City, TN, USA). All cavities were restored with glass-ionomer cement (GC Fuji VIII, GC Corporation, Tokyo, Japan). The observational period was 28 days, after which the animal was sacrificed and histological preparations were made. A light microscope was used to analyze dentin bridge formation, tissue reorganization and inflammation, and the presence of bacteria in the pulp. The formation of dentin bridge was observed in the experimental and control groups. Inflammation of the pulp was mild to moderate in both groups. Angiogenesis and many odontoblast-like cells, responsible for dentin bridge formation, were observed. Necrosis was not observed in any case, nor were bacteria present in the pulp. Histological analysis indicated a favorable therapeutic effect of Emdogain® Gel in direct pulp capping of Vietnamese pigs. Pulp reaction was similar to that of MTA®.

Effects of Growth Factors on Dental Stem/ProgenitorCells

PubMed Central

Kim, Sahng G.; Solomon, Charles; Zheng, Ying; Suzuki, Takahiro; Mo, Chen; Song, Songhee; Jiang, Nan; Cho, Shoko; Zhou, Jian; Mao, Jeremy J.

2014-01-01

Synopsis The primary goal of regenerative endodontics is to restore the vitality and functions of the dentin-pulp complex, as opposed to filing of the root canal with bioinert materials. Structural restoration is also important but is likely secondary to vitality and functions. Myriads growth factors regulate multiple cellular functions including migration, proliferation, differentiation and apoptosis of several cell types that are intimately involved in dentin-pulp regeneration: odontoblasts, interstitial fibroblasts, vascular-endothelial cells and sprouting nerve fibers. Recent work showing that growth factor delivery, without cell transplantation, can yield pulp-dentin like tissues in vivo provides one of the tangible pathways for regenerative endodontics. This review synthesizes our knowledge on a multitude of growth factors that are known or anticipated to be efficacious in dental pulp-dentin regeneration. PMID:22835538

Characterization of dental pulp defect and repair in a canine model.

PubMed

Yildirim, Sibel; Can, Alp; Arican, Mustafa; Embree, Mildred C; Mao, Jeremy J

2011-12-01

To explore a relationship between the size of pulp chamber perforation and reparative dentin formation in a canine model. Pulp defects were created in the pulp chambers of maxillary and mandibular premolars (N = 64) in 17 healthy mongrel dogs in three different sizes (diameter/depth: 1/1, 2/1, and 2/2 mm3) with sterile round burs under general anesthesia. The perforations were immediately capped with hard-setting calcium hydroxide (CH) in the control group or sealed with Teflon membrane (TM) in the experimental group, followed by restoration with reinforced zinc oxide eugenol cement in vivo. Seven and 30 days after pulp chamber perforation and restoration all treated and control premolars were extracted and prepared for histomorphometric and statistical analyses. Reparative dentin formation was more pronounced for defect sizes up to 2/1 mm3 when treated with CH, and completely bridged the surgically created dentin defects only after 30 days. However, reparative dentin upon CH treatment failed to completely bridge pulp chamber exposure for 2/2 defects. By contrast, TM treatment only yielded mild reparative dentin bridging for defects up to 1/1, but not for either 2/1 or 2/2 defects at 30 days. Inflammatory responses of the exposed dental pulp tissue were more robust with the TM group than with the CH group. Thus, dental pulp tissue possesses a capacity for spontaneous repair by the formation of reparative dentin in this preclinical model, but only up to a defect size of -2 mm in diameter and 1 mm in depth. All observations are based on 30 days post-treatment in the canine model. These findings may serve as baseline for regenerative endodontic studies.

Mechanical properties of new dental pulp-capping materials.

PubMed

Nielsen, Matthew J; Casey, Jeffery A; VanderWeele, Richard A; Vandewalle, Kraig S

2016-01-01

The mechanical properties of pulp-capping materials may affect their resistance to fracture during placement of a final restorative material or while supporting an overlying restoration over time. The purpose of this study was to compare the compressive strength, flexural strength, and flexural modulus of 2 new pulp-capping materials (TheraCal LC and Biodentine), mineral trioxide aggregate (MTA), and calcium hydroxide over time. Specimens were created in molds and tested to failure in a universal testing machine after 15 minutes, 3 hours, and 24 hours. The MTA specimens did not set at 15 minutes. At all time periods, TheraCal LC had the greatest compressive and flexural strengths. After 3 and 24 hours, Biodentine had the greatest flexural modulus. TheraCal LC had greater early strength to potentially resist fracture during immediate placement of a final restorative material. Biodentine had greater stiffness after 3 hours to potentially provide better support of an overlying restoration under function over time.

[Ru(bipy)3]2+ nanoparticle-incorporate dental light cure resin to promote photobiomodulation therapy for enhanced vital pulp tissue repair

NASA Astrophysics Data System (ADS)

Mosca, Rodrigo C.; Young, Nicholas; Zeituni, Carlos A.; Arany, Praveen R.

2018-02-01

The use of nanoparticle on dental light cure resin is not new, currently several compounds (nanoadditives) are used to promote better communication between the restorative material and biological tissues. The interest for this application is growing up to enhance mechanical proprieties to dental tissue cells regeneration. Bioactive nanoparticles and complex compounds with multiple functions are the major target for optimizing the restorative materials. In this work, we incorporate [Ru(bipy)3]2+ nanoparticles, that absorbs energy at 450 nm (blue-light) and emits strongly at 620 nm (red-light), in PLGA Microspheres and insert it in Dental Light Cure Resin to promote the Photobiomodulation Therapy (PBM) effects to accelerate dental pulp repair by in vitro using cytotoxicity and proliferation assay.

Deciphering the Epigenetic Code in Embryonic and Dental Pulp Stem Cells

PubMed Central

Bayarsaihan, Dashzeveg

2016-01-01

A close cooperation between chromatin states, transcriptional modulation, and epigenetic modifications is required for establishing appropriate regulatory circuits underlying self-renewal and differentiation of adult and embryonic stem cells. A growing body of research has established that the epigenome topology provides a structural framework for engaging genes in the non-random chromosomal interactions to orchestrate complex processes such as cell-matrix interactions, cell adhesion and cell migration during lineage commitment. Over the past few years, the functional dissection of the epigenetic landscape has become increasingly important for understanding gene expression dynamics in stem cells naturally found in most tissues. Adult stem cells of the human dental pulp hold great promise for tissue engineering, particularly in the skeletal and tooth regenerative medicine. It is therefore likely that progress towards pulp regeneration will have a substantial impact on the clinical research. This review summarizes the current state of knowledge regarding epigenetic cues that have evolved to regulate the pluripotent differentiation potential of embryonic stem cells and the lineage determination of developing dental pulp progenitors. PMID:28018144

Clinical antibacterial effectiveness and biocompatibility of gaseous ozone after incomplete caries removal.

PubMed

Krunić, Jelena; Stojanović, Nikola; Đukić, Ljiljana; Roganović, Jelena; Popović, Branka; Simić, Ivana; Stojić, Dragica

2018-06-01

To evaluate local effect of gaseous ozone on bacteria in deep carious lesions after incomplete caries removal, using chlorhexidine as control, and to investigate its effect on pulp vascular endothelial growth factor (VEGF), neuronal nitric oxide synthase (nNOS), and superoxide dismutase (SOD). Antibacterial effect was evaluated in 48 teeth with diagnosed deep carious lesion. After incomplete caries removal, teeth were randomly allocated into two groups regarding the cavity disinfectant used: ozone (open system) or 2% chlorhexidine. Dentin samples were analyzed for the presence of total bacteria and Lactobacillus spp. by real-time quantitative polymerase chain reaction. For evaluation of ozone effect on dental pulp, 38 intact permanent teeth indicated for pulp removal/tooth extraction were included. After cavity preparation, teeth were randomly allocated into two groups: ozone group and control group. VEGF/nNOS level and SOD activity in dental pulp were determined by enzyme-linked immunosorbent assay and spectrophotometric method, respectively. Ozone application decreased number of total bacteria (p = 0.001) and Lactobacillus spp. (p < 0.001), similarly to chlorhexidine. The VEGF (p < 0.001) and nNOS (p = 0.012) levels in dental pulp after ozone application were higher, while SOD activity was lower (p = 0.001) comparing to those in control pulp. Antibacterial effect of ozone on residual bacteria after incomplete caries removal was similar to that of 2% chlorhexidine. Effect of ozone on pulp VEGF, nNOS, and SOD indicated its biocompatibility. Ozone appears as effective and biocompatible cavity disinfectant in treatment of deep carious lesions by incomplete caries removal technique.

The Interplay of Dental Pulp Stem Cells and Endothelial Cells in an Injectable Peptide Hydrogel on Angiogenesis and Pulp Regeneration In Vivo

PubMed Central

Dissanayaka, Waruna Lakmal; Hargreaves, Kenneth M.; Jin, Lijian; Samaranayake, Lakshman P.

2015-01-01

Securing an adequate blood supply for the survival of cell transplants is critical for a successful outcome in tissue engineering. Interactions between endothelial and progenitor/stem cells are important for vascularization of regenerating tissue. Recently, self-assembling peptide nanofibers were described as a promising environment for pulp regeneration due to their synthetic nature and controlled physicochemical properties. In this study, the peptide hydrogel PuraMatrix™ was used as a scaffold system to investigate the role of dental pulp stem cells (DPSCs) in triggering angiogenesis and the potential for regenerating vascularized pulp in vivo. Human umbilical vein endothelial cells (HUVECs), DPSCs, or cocultures of both cell types were encapsulated in three-dimensional PuraMatrix. The peptide nanofiber microenvironment supported cell survival, cell migration, and capillary network formation in the absence of exogenous growth factors. DPSCs increased early vascular network formation by facilitating the migration of HUVECs and by increasing vascular endothelial growth factor (VEGF) expression. Both the DPSC-monoculture and coculture groups exhibited vascularized pulp-like tissue with patches of osteodentin after transplantation in mice. The cocultured groups exhibited more extracellular matrix, vascularization, and mineralization than the DPSC-monocultures in vivo. The DPSCs play a critical role in initial angiogenesis, whereas coordinated efforts by the HUVECs and DPSCs are required to achieve a balance between extracellular matrix deposition and mineralization. The findings of this study also highlighted the importance of a microenvironment that supports cell–cell interactions and cell migration, which contribute to successful dental pulp regeneration. PMID:25203774

Stem cells in dentistry--review of literature.

PubMed

Dziubińska, P; Jaskólska, M; Przyborowska, P; Adamiak, Z

2013-01-01

Stem cells have been successfully isolated from a variety of human and animal tissues, including dental pulp. This achievement marks progress in regenerative dentistry. This article reviews the latest improvements made in regenerative dental medicine with the involvement of stem cells. Although, various types of multipotent somatic cells can be applied in dentistry, two types of cells have been investigated in this review. Dental pulp cells are classified as: DPSCs, SCAPs and SHEDs.The third group includes two types of cell associated with the periodontium: PDL and DFPC. This review aims to systematize basic knowledge about cellular engineering in dentistry.

Systemically Transplanted Bone Marrow-derived Cells Contribute to Dental Pulp Regeneration in a Chimeric Mouse Model.

PubMed

Xu, Wenan; Jiang, Shan; Chen, Qiuyue; Ye, Yanyan; Chen, Jiajing; Heng, Boon Chin; Jiang, Qianli; Wu, Buling; Ding, Zihai; Zhang, Chengfei

2016-02-01

Migratory cells via blood circulation or cells adjacent to the root apex may potentially participate in dental pulp tissue regeneration or renewal. This study investigated whether systemically transplanted bone marrow cells can contribute to pulp regeneration in a chimeric mouse model. A chimeric mouse model was created through the injection of bone marrow cells from green fluorescent protein (GFP) transgenic C57BL/6 mice into the tail veins of recipient wild-type C57BL/6 mice that had been irradiated with a lethal dose of 8.5 Gy from a high-frequency linear accelerator. These mice were subjected to pulpectomy and pulp revascularization. At 1, 4, and 8 weeks after surgery, in vivo animal imaging and histologic analyses were conducted. In vivo animal imaging showed that the green biofluorescence signal from the transplanted GFP+ cells increased significantly and was maintained at a high level during the first 4 weeks after surgery. Immunofluorescence analyses of tooth specimens collected at 8 weeks postsurgery showed the presence of nestin+/GFP+, α smooth muscle actin (α-SMA)/GFP+, and NeuN/GFP+ cells within the regenerated pulplike tissue. These data confirm that transplanted bone marrow-derived cells can contribute to dental pulp regeneration. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Responses of the pulp, periradicular and soft tissues following trauma to the permanent teeth.

PubMed

Yu, C Y; Abbott, P V

2016-03-01

Trauma to the permanent teeth involves not only the teeth but also the pulp, the periodontal ligament, alveolar bone, gingiva and other associated structures. There are many variations in the types of injuries with varying severity and often a tooth may sustain more than one injury at the same time. In more severe trauma cases, there are many different cellular systems of mineralized hard and unmineralized soft tissues involved, each with varying potential for healing. Furthermore, the responses of the different tissues may be interrelated and dependent on each other. Hence, healing subsequent to dental trauma has long been known to be very complex. Because of this complexity, tissue responses and the consequences following dental trauma have been confusing and puzzling for many clinicians. In this review, the tissue responses are described under the tissue compartments typically involved following dental trauma: the pulp, periradicular and associated soft tissues. The factors involved in the mechanisms of trauma are analysed for their effects on the tissue responses. A thorough understanding of the possible tissue responses is imperative for clinicians to overcome the confusion and manage dental trauma adequately and conservatively in order to minimize the consequences following trauma. © 2016 Australian Dental Association.

A preliminary report on histological outcome of pulpotomy with endodontic biomaterials vs calcium hydroxide.

PubMed

Nosrat, Ali; Peimani, Ali; Asgary, Saeed

2013-11-01

The purpose of the study was to evaluate human dental pulp response to pulpotomy with calcium hydroxide (CH), mineral trioxide aggregate (MTA), and calcium enriched mixture (CEM) cement. A total of nine erupted third molars were randomly assigned to each pulpotomy group. The same clinician performed full pulpotomies and coronal restorations. The patients were followed clinically for six months; the teeth were then extracted and prepared for histological assessments. The samples were blindly assessed by an independent observer for pulp vitality, pulp inflammation, and calcified bridge formation. All patients were free of clinical signs/symptoms of pulpal/periradicular diseases during the follow up period. In CH group, one tooth had necrotic radicular pulp; other two teeth in this group had vital uninflamed pulps with complete dentinal bridge formation. In CEM cement and MTA groups all teeth had vital uninflamed radicular pulps. A complete dentinal bridge was formed beneath CEM cement and MTA in all roots. Odontoblast-like cells were present beneath CEM cement and MTA in all samples. This study revealed that CEM cement and MTA were reliable endodontic biomaterials in full pulpotomy treatment. In contrast, the human dental pulp response to CH might be unpredictable.

21 CFR 872.1730 - Electrode gel for pulp testers.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Electrode gel for pulp testers. 872.1730 Section 872.1730 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1730 Electrode gel for pulp testers. (a...

21 CFR 872.1730 - Electrode gel for pulp testers.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Electrode gel for pulp testers. 872.1730 Section 872.1730 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1730 Electrode gel for pulp testers. (a...

Effect of white mineral trioxide aggregate compared with biomimetic carbonated apatite on dentine bridge formation and inflammatory response in a dental pulp model.

PubMed

Danesh, F; Vahid, A; Jahanbani, J; Mashhadiabbas, F; Arman, E

2012-01-01

  To evaluate the effects of apatite precipitation on the biocompatibility and hard tissue induction properties of white mineral trioxide aggregate (WMTA) in a dental pulp model.   Pulp exposures were created on the axial walls of 32 sound canine teeth of eight dogs. Four additional sound teeth served as controls. The pulps were capped either with WMTA or apatite derivatives [biomimetic carbonated apatite (BCAp)] in the interaction of WMTA with a synthetic tissue fluid and restored with zinc oxide-eugenol cement. After 7 and 70 days, the animals were killed, and the histological specimens taken from the teeth were stained with haematoxylin and eosin for histomorphological evaluation. The Brown and Brenn technique was employed to stain bacteria. The data were subjected to nonparametric Kruskall-Wallis analysis and Mann-Whitney U_tests.   Biomimetic carbonated apatite did not induce hard tissue bridge formation. WMTA performed significantly better than BCAp in this respect at both periods (P < 0.05). BCAp was associated with a significantly greater inflammatory response as compared with WMTA after 7 days (P < 0.05). Both materials were associated with similar reactions after 70 days (P >0.05).   White mineral trioxide aggregate induced hard tissue formation via a mechanism other than that postulated via apatite formation. © 2011 International Endodontic Journal.

Regenerative medicine using dental pulp stem cells for liver diseases.

PubMed

Ohkoshi, Shogo; Hara, Hajime; Hirono, Haruka; Watanabe, Kazuhiko; Hasegawa, Katsuhiko

2017-02-06

Acute liver failure is a refractory disease and its prognosis, if not treated using liver transplantation, is extremely poor. It is a good candidate for regenerative medicine, where stem cell-based therapies play a central role. Mesenchymal stem cells (MSCs) are known to differentiate into multiple cell lineages including hepatocytes. Autologous cell transplant without any foreign gene induction is feasible using MSCs, thereby avoiding possible risks of tumorigenesis and immune rejection. Dental pulp also contains an MSC population that differentiates into hepatocytes. A point worthy of special mention is that dental pulp can be obtained from deciduous teeth during childhood and can be subsequently harvested when necessary after deposition in a tooth bank. MSCs have not only a regenerative capacity but also act in an anti-inflammatory manner via paracrine mechanisms. Promising efficacies and difficulties with the use of MSC derived from teeth are summarized in this review.

Concise Review: Dental Pulp Stem Cells: A Novel Cell Therapy for Retinal and Central Nervous System Repair.

PubMed

Mead, Ben; Logan, Ann; Berry, Martin; Leadbeater, Wendy; Scheven, Ben A

2017-01-01

Dental pulp stem cells (DPSC) are neural crest-derived ecto-mesenchymal stem cells that can relatively easily and non-invasively be isolated from the dental pulp of extracted postnatal and adult teeth. Accumulating evidence suggests that DPSC have great promise as a cellular therapy for central nervous system (CNS) and retinal injury and disease. The mode of action by which DPSC confer therapeutic benefit may comprise multiple pathways, in particular, paracrine-mediated processes which involve a wide array of secreted trophic factors and is increasingly regarded as the principal predominant mechanism. In this concise review, we present the current evidence for the use of DPSC to repair CNS damage, including recent findings on retinal ganglion cell neuroprotection and regeneration in optic nerve injury and glaucoma. Stem Cells 2017;35:61-67. © 2016 AlphaMed Press.

Investigation of functional activity human dental pulp stem cells at acute and chronic pulpitis.

PubMed

Ustiashvili, M; Kordzaia, D; Mamaladze, M; Jangavadze, M; Sanodze, L

2014-09-01

It is already recognized that together with the other connective tissues organ-specific progenic stem cells are also found in postnatal dental pulp. This group of undifferentiated cells is only 1% of total cell population of the pulp. The aim of the study was the identification of stem cells in human dental pulp, detection of their localization and assessment of functional activity during inflammation process and/or at norm. The obtained results showed that at acute pulpitis the pulp stroma is hypocellular in comparison with the norm but cells proliferative activity is low. CD 133 and NCAM (CD 56) positive stem cells were found in perivascularl space of the pulp stroma and in Hohle layer. At process prolongation and transition to the chronic phase pulp stroma is hypercellular, the cells with large, rounded or oval-shaped nuclei with clear chromatin appear together with fibroblasts. They are distributed as about entire thickness of the stroma as especially Hohle layer. In such cells higher proliferative activity (Ki67 expression) was observed. The cells in the mentioned proliferation phase are intensively marked by CD133, the rate of which is high in Hohle layer and along it. A large number of NCAM (CD 56) positive cells appear in pulp stroma. During pulpitis an involvement of stem cells into the process of reparative dentinogenesis should be conducted stepwise. In acute cases of the disease, stem cell perivascularl mobilization and proliferation and its migration to Hohle layer occur in response to irritation /stimulation. Chronification of the process leads not only to the migration of stem cells to the periphery of the pulp but also s their В«maturationВ» (increase of NCAM expression in the stem cells), which causes an increase the number of dentin producing active odontoblasts and initiation of reparative dentinogenesis.

Trophic Effects and Regenerative Potential of Mobilized Mesenchymal Stem Cells From Bone Marrow and Adipose Tissue as Alternative Cell Sources for Pulp/Dentin Regeneration.

PubMed

Murakami, Masashi; Hayashi, Yuki; Iohara, Koichiro; Osako, Yohei; Hirose, Yujiro; Nakashima, Misako

2015-01-01

Dental pulp stem cell (DPSC) subsets mobilized by granulocyte-colony-stimulating factor (G-CSF) are safe and efficacious for complete pulp regeneration. The supply of autologous pulp tissue, however, is very limited in the aged. Therefore, alternative sources of mesenchymal stem/progenitor cells (MSCs) are needed for the cell therapy. In this study, DPSCs, bone marrow (BM), and adipose tissue (AD)-derived stem cells of the same individual dog were isolated using G-CSF-induced mobilization (MDPSCs, MBMSCs, and MADSCs). The positive rates of CXCR4 and G-CSFR in MDPSCs were similar to MADSCs and were significantly higher than those in MBMSCs. Trophic effects of MDPSCs on angiogenesis, neurite extension, migration, and antiapoptosis were higher than those of MBMSCs and MADSCs. Pulp-like loose connective tissues were regenerated in all three MSC transplantations. Significantly higher volume of regenerated pulp and higher density of vascularization and innervation were observed in response to MDPSCs compared to MBMSC and MADSC transplantation. Collagenous matrix containing dentin sialophosphoprotein (DSPP)-positive odontoblast-like cells was the highest in MBMSCs and significantly higher in MADSCs compared to MDPSCs. MBMSCs and MADSCs, therefore, have potential for pulp regeneration, although the volume of regenerated pulp tissue, angiogenesis, and reinnervation, were less. Thus, in conclusion, an alternative cell source for dental pulp/dentin regeneration are stem cells from BM and AD tissue.

Mesenchymal stem cell characteristics of dental pulp and periodontal ligament stem cells after in vivo transplantation.

PubMed

Lei, Ming; Li, Kun; Li, Bei; Gao, Li-Na; Chen, Fa-Ming; Jin, Yan

2014-08-01

Mesenchymal stem cells (MSCs) isolated from human postnatal dental pulp and periodontal ligament (PDL) tissues can give rise to multilineage differentiation in vitro and generate related dental tissues in vivo. However, the cell properties of human dental pulp stem cells (DPSCs) and PDL stem cells (PDLSCs) after in vivo implantation remain largely unidentified. In this study, cells were re-isolated from in vivo-generated dental pulp-like and PDL-like tissues (termed re-DPCs and re-PDLCs, respectively) as a result of ectopic transplantation of human DPSC and PDLSC sheets. The cell characteristics in terms of colony-forming ability, cell surface antigens and multi-differentiation potentials were all evaluated before and after implantation. It was found that re-DPCs and re-PDLCs were of human and mesenchymal origin and positive for MSC markers such as STRO-1, CD146, CD29, CD90 and CD105; and, to some extent, re-DPCs could maintain their colony forming abilities. Moreover, both cell types were able to form mineral deposits and differentiate into adipocytes and chondrocytes; however, quantitative analysis and related gene expression determination showed that the osteo-/chondro-differentiation capabilities of re-DPCs and re-PDLCs were significantly reduced compared to those of DPSCs and PDLSCs, respectively (P < 0.05); re-PDLCs showed a greater reduction potential than re-DPCs. We conclude that DPSCs and PDLSCs may maintain their MSC characteristics after in vivo implantation and, compared to PDLSCs, DPSCs appear much more stable under in vivo conditions. These findings provide additional cellular and molecular evidence that supports expanding the use of dental tissue-derived stem cells in cell therapy and tissue engineering. Copyright © 2014 Elsevier Ltd. All rights reserved.

Interaction between mDia1 and ROCK in Rho-induced migration and adhesion of human dental pulp cells.

PubMed

Cheng, L; Xu, J; Qian, Y Y; Pan, H Y; Yang, H; Shao, M Y; Cheng, R; Hu, T

2017-01-01

To investigate the effects of mammalian homologue of Drosophila diaphanous-1(mDia1) and Rho-associated coiled-coil-containing protein kinase (ROCK) on the migration and adhesion of dental pulp cells (DPCs). Lysophosphatidic acid (LPA) was used to activate Rho signalling. mDia1 and ROCK were inhibited by short interfering RNA and the specific inhibitor, Y-27632, respectively. The migration of DPCs was assessed using the transwell migration assay and scratch test. Formation of cytoskeleton and focal adhesions(FAs) was observed by confocal laser scanning microscopy. Cell adhesion and spreading assays were performed. Phosphorylation of focal adhesion kinase (FAK) and paxillin was detected by Western blotting, and the bands were analysed using Adobe Photoshop CS5 software. All experiments were performed at least three times, and data were analysed with one-way anova and a post hoc test. LPA-triggered activation of Rho and inhibition of ROCK significantly increased the cell migration rate. Cell migration was inhibited by silencing mDia1. mDia1 silencing and ROCK inhibition suppressed the LPA-induced formation of the cytoskeleton, FA and phosphorylation of FAK and paxillin. Inhibition of ROCK or mDia1 facilitated early cell adhesion and spreading; by contrast, the combined inhibition of ROCK and mDia1 neutralized these effects. mDia1 promoted RhoA-induced migration of DPCs, but ROCK had an opposite effect. Both mDia1 and ROCK participated in cytoskeleton formation and adhesion of DPCs. The interactions between mDia1 and ROCK might influence dental pulp repair by determining the migration and adhesion of DPCs. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Pulp calcification in traumatized primary teeth: prevalence and associated factors.

PubMed

Mello-Moura, A C V; Bonini, G A V C; Zardetto, C G D C; Rodrigues, C R M D; Wanderley, M T

2011-01-01

To establish the prevalence of pulp calcifications in 946 patients at the Research and Clinical Center of Dental Trauma in Primary Teeth. The clinical and radiographic records of l675 traumatized primary teeth were evaluated. Statistical analysis was performed using chi-square and univariate logistic regression. 197 (20.8%) patients showed pulp calcification (PC). A total of 250 (14.9%) calcified teeth were observed In most teeth, PC appeared within the first 12 months following trauma. PC prevalence was higher in cases of repeated trauma (29.6%) than in single trauma (16.4%), p < 0.05, with a 2.14 chance of showing pulp calcification when a child suffered recurrent trauma. Most teeth showing calcified pulp, suffered trauma to the supportive tissue (67.4%), being statistically significant in relation to the trauma to dental tissue (p < 0.05). PC is a sequelae in cases of trauma to the primary dentition; teeth that suffered recurrent traumatic injuries show higher risk of presenting.

Thermal effects of the Er:YAG laser on a simulated dental pulp: a quantitative evaluation of the effects of a water spray.

PubMed

Attrill, D C; Davies, R M; King, T A; Dickinson, M R; Blinkhorn, A S

2004-01-01

To quantify the temperature increments in a simulated dental pulp following irradiation with an Er:YAG laser, and to compare those increments when the laser is applied with and without water spray. Two cavities were prepared on either the buccal or lingual aspect of sound extracted teeth using the laser. One cavity was prepared with water spray, the other without and the order of preparation randomised. Identical preparation parameters were used for both cavities. Temperature increments were measured in the pulp chamber using a calibrated thermocouple and a novel pulp simulant. Maximum increments were 4.0 degrees C (water) and 24.7 degrees C (no water). Water was shown to be highly significant in reducing the overall temperature increments in all cases (p<0.001; paired t-test). None of the samples prepared up to a maximum of 135 J cumulative energy prepared with water spray exceeded that threshold at which pulpal damage can be considered to occur. Only 25% of those prepared without water spray remained below this threshold. Extrapolation of the figures suggests probably tolerable limits of continuous laser irradiation with water in excess to 160 J. With the incorporation of small breaks in the continuity of laser irradiation that occur in the in vivo situation, the cumulative energy dose tolerated by the pulp should far exceed these figures. The Er:YAG laser must be used in conjunction with water during cavity preparation. As such it should be considered as an effective tool for clinical use based on predicted pulpal responses to thermal stimuli.

Tooth Tissue Engineering: The Importance of Blood Products as a Supplement in Tissue Culture Medium for Human Pulp Dental Stem Cells.

PubMed

Pisciolaro, Ricardo Luiz; Duailibi, Monica Talarico; Novo, Neil Ferreira; Juliano, Yara; Pallos, Debora; Yelick, Pamela Crotty; Vacanti, Joseph Phillip; Ferreira, Lydia Masako; Duailibi, Silvio Eduardo

2015-11-01

One of the goals in using cells for tissue engineering (TE) and cell therapy consists of optimizing the medium for cell culture. The present study compares three different blood product supplements for improved cell proliferation and protection against DNA damage in cultured human dental pulp stem cells for tooth TE applications. Human cells from dental pulp were first characterized as adult stem cells (ectomesenchymal mixed origin) by flow cytometry. Next, four different cell culture conditions were tested: I, supplement-free; II, supplemented with fetal bovine serum; III, allogeneic human serum; and IV, autologous human serum. Cultured cells were then characterized for cell proliferation, mineralized nodule formation, and colony-forming units (CFU) capability. After 28 days in culture, the comet assay was performed to assess possible damage in cellular DNA. Our results revealed that Protocol IV achieved higher cell proliferation than Protocol I (p = 0.0112). Protocols II and III resulted in higher cell proliferation than Protocol I, but no statistical differences were found relative to Protocol IV. The comet assay revealed less cell damage in cells cultured using Protocol IV as compared to Protocols II and III. The damage percentage observed on Protocol II was significantly higher than all other protocols. CFUs capability was highest using Protocol IV (p = 0.0018) and III, respectively, and the highest degree of mineralization was observed using Protocol IV as compared to Protocols II and III. Protocol IV resulted in significantly improved cell proliferation, and no cell damage was observed. These results demonstrate that human blood product supplements can be used as feasible supplements for culturing adult human dental stem cells.

[The application of laser in endodontics].

PubMed

He, W X; Liu, N N; Wang, X L; He, X Y

2016-08-01

Since laser was introduced in the field of medicine in 1970's, its application range has continuously expanded. The application of laser in endodontics also increased due to its safety and effectiveness in dental treatments. The majority of the laser application researches in dentistry focused on dentin hypersensitivity, removal of carious tissues, tooth preparations, pulp capping or pulpotomy, and root canal treatment. In this article, we reviewed literature on the effects of laser in the treatments of dental and pulp diseases.

[Daily practice and pulp diseases].

PubMed

Calmein, S; Claisse, A

1990-09-01

Constructive or destructive processes of pulp tissue depend on many factors: anatomic topography, particular physiology, or intensity and duration of infectious, mechanical and chemical aggression. Also irritation of the pulpo-dentinal complex induce histologic and physiologic changes. The positive diagnosis of hyperemia, acute or chronic pulpitis, pulpal necrosis and acute or chronic apical abscess is performed by clinical investigations which allow a differential diagnosis with other dental or extra-dental diseases. These multiple steps lead to an adapted and appropriate treatment.

[Results of 30 children treated under dental general anesthesia in pediatric dentistry].

PubMed

Chen, Xu; Liu, Yao; Jin, Shi-fu; Zhang, Qian; Jin, Xuan-yu

2008-12-01

To determine the age and sex characteristics of the children and type of dental procedures performed under dental general anesthesia (DGA) and to assess the results after six months to one year's follow-up. A sample of 30 patients treated under dental general anesthesia (DGA) during 2006-2007 in the Department of Pediatric Dentistry of China Medical University was reviewed. All the teeth were treated one time. The dental procedures performed included caries restoration, indirect pulp capping, pulpotomy, root canal therapy (RCT) and dental extraction. Oral prophylaxis and topical fluoride applications were performed on all teeth. Pit and fissure sealing was performed on all healthy premolars and molars. SPSS10.0 software package was used for statistical analysis. Chi-square test was used to analyze the difference of the sex distribution in different age group and the difference of dental procedures performed between the primary teeth and the permanent teeth. The age of the patients ranged from 19 months to 14 years. The mental retardation patients accounted for 10% and mental healthy patients accounted for 90% of the sample studied. Males were more than females with the ratio about 2 to 1 in each age group. The dental procedures performed were caries restoration (18.67%), indirect pulp capping (23.26%), pulpotomy (0.77%), RCT (29.16%), dental extractions (2.05%) and fissure sealants (26.09%). The percentage of RCT was higher than that of caries restoration in the primary teeth, whereas the result was opposite as for the permanent teeth as indicated by Chi-square test (X(2)=11.630, P=0.001). New dental caries was not found except 2 patients who suffered from dysnoesia and were not cooperative to have regular examination. Fillings were lost in 3 cases, with 3 anterior teeth and 2 posterior teeth after RCT. All the children could cooperate except two mental retardation patients during the follow-up visit. Caries restoration and RCT are the most frequently performed procedures in pediatric patients using DGA. This indicates the need to design and implement integrate control and prevention programs for special pediatric patients. DGA is a safe and effective behavior management technique to treat uncooperative children.

Thermotransduction and heat stress in dental structures during orthodontic debonding : Effectiveness of various cooling strategies.

PubMed

Kley, Philipp; Frentzen, Matthias; Küpper, Katharina; Braun, Andreas; Kecsmar, Susann; Jäger, Andreas; Wolf, Michael

2016-05-01

Recent studies have indicated possible thermal damage to pulpal tissue during orthodontic debonding. This study aimed to analyze the thermal loads acting upon dental structures and their transfer to the pulp during orthodontic debonding. Specific goals were to analyze temperature changes in local dental tissues, thermotransduction to the pulp cavity, and the effectiveness of common cooling strategies and of simulated intrapulpal circulation. Metal brackets were bonded to five extracted human molars and subsequently removed. While a carbide bur was applied to debond the residual composite from the tooth surface, various cooling strategies (no/air/water cooling) were employed with or without simulated intrapulpal circulation, accompanied by temperature measurements with a thermographic infrared camera on the enamel surface and with measuring probes in the pulp cavity. Appropriate evaluation software was used to calculate the enamel-to-pulp temperature gradients and for statistical analysis. Significant differences in temperature rise and heat development over time, both on the enamel surfaces and in the pulp cavities were found. The mean temperature rises associated with no/air/water cooling were 90.7/46.6/9.2 °C on the enamel surface versus 9/8/4.6 °C inside the pulp. However, thermotransduction from enamel to pulp remained below 10 % of the surface measurements in all groups. Simulated intrapulpal microcirculation was found to significantly reduce intrapulpal temperature levels. During debonding of residual bracket adhesives, provided that a carbide bur is properly used, our data indicate a low risk of reaching critical intrapulpal temperatures even in the absence of dedicated cooling and no risk if the instrumentation is accompanied by air or water cooling.

Temperature excursions at the pulp-dentin junction during the curing of light-activated dental restorations.

PubMed

Jakubinek, Michael B; O'Neill, Catherine; Felix, Chris; Price, Richard B; White, Mary Anne

2008-11-01

Excessive heat produced during the curing of light-activated dental restorations may injure the dental pulp. The maximum temperature excursion at the pulp-dentin junction provides a means to assess the risk of thermal injury. In this investigation we develop and evaluate a model to simulate temperature increases during light-curing of dental restorations and use it to investigate the influence of several factors on the maximum temperature excursion along the pulp-dentin junction. Finite element method modeling, using COMSOL 3.3a, was employed to simulate temperature distributions in a 2D, axisymmetric model tooth. The necessary parameters were determined from a combination of literature reports and our measurements of enthalpy of polymerization, heat capacity, density, thermal conductivity and reflectance for several dental composites. Results of the model were validated using in vitro experiments. Comparisons with in vitro experiments indicate that the model provides a good approximation of the actual temperature increases. The intensity of the curing light, the curing time and the enthalpy of polymerization of the resin composite were the most important factors. The composite is a good insulator and the greatest risk occurs when using the light to cure the thin layer of bonding resin or in deep restorations that do not have a liner to act as a thermal barrier. The results show the importance of considering temperature increases when developing curing protocols. Furthermore, we suggest methods to minimize the temperature increase and hence the risk of thermal injury. The physical properties measured for several commercial composites may be useful in other studies.

Overexpression of Receptor for Advanced Glycation End Products and High-Mobility Group Box 1 in Human Dental Pulp Inflammation

PubMed Central

Tancharoen, Salunya; Tengrungsun, Tassanee; Suddhasthira, Theeralaksna; Kikuchi, Kiyoshi; Vechvongvan, Nuttavun; Maruyama, Ikuro

2014-01-01

High mobility group box 1 (HMGB1), a nonhistone DNA-binding protein, is released into the extracellular space and promotes inflammation. HMGB1 binds to related cell signaling transduction receptors, including receptor for advanced glycation end products (RAGE), which actively participate in vascular and inflammatory diseases. The aim of this study was to examine whether RAGE and HMGB1 are involved in the pathogenesis of pulpitis and investigate the effect of Prevotella intermedia (P. intermedia) lipopolysaccharide (LPS) on RAGE and HMGB1 expression in odontoblast-like cells (OLC-1). RAGE and HMGB1 expression levels in clinically inflamed dental pulp were higher than those in healthy dental pulp. Upregulated expression of RAGE was observed in odontoblasts, stromal pulp fibroblasts-like cells, and endothelial-like cell lining human pulpitis tissue. Strong cytoplasmic HMGB1 immunoreactivity was noted in odontoblasts, whereas nuclear HMGB1 immunoreactivity was seen in stromal pulp fibroblasts-like cells in human pulpitis tissue. LPS stimulated OLC-1 cells produced HMGB1 in a dose-dependent manner through RAGE. HMGB1 translocation towards the cytoplasm and secretion from OLC-1 in response to LPS was inhibited by TPCA-1, an inhibitor of NF-κB activation. These findings suggest that RAGE and HMGB1 play an important role in the pulpal immune response to oral bacterial infection. PMID:25114379

Adult stem cell-based apexogenesis

PubMed Central

Li, Yao; Shu, Li-Hong; Yan, Ming; Dai, Wen-Yong; Li, Jun-Jun; Zhang, Guang-Dong; Yu, Jin-Hua

2014-01-01

Generally, the dental pulp needs to be removed when it is infected, and root canal therapy (RCT) is usually required in which infected dental pulp is replaced with inorganic materials (paste and gutta percha). This treatment approach ultimately brings about a dead tooth. However, pulp vitality is extremely important to the tooth itself, since it provides nutrition and acts as a biosensor to detect the potential pathogenic stimuli. Despite the reported clinical success rate, RCT-treated teeth are destined to be devitalized, brittle and susceptible to postoperative fracture. Recently, the advances and achievements in the field of stem cell biology and regenerative medicine have inspired novel biological approaches to apexogenesis in young patients suffering from pulpitis or periapical periodontitis. This review mainly focuses on the benchtop and clinical regeneration of root apex mediated by adult stem cells. Moreover, current strategies for infected pulp therapy are also discussed here. PMID:25332909

Inflammatory and immunological aspects of dental pulp repair

PubMed Central

Goldberg, Michel; Farges, Jean-Christophe; Lacerda-Pinheiro, Sally; Six, Ngampis; Jegat, Nadège; Decup, Frank; Septier, Dominique; Carrouel, Florence; Durand, Stéphanie; Chaussain-Miller, Catherine; DenBesten, Pamela; Veis, Arthur; Poliard, Anne

2010-01-01

The repair of dental pulp by direct capping with calcium hydroxide or by implantation of bioactive extracellular matrix (ECM) molecules implies a cascade of four steps: a moderate inflammation, the commitment of adult reserve stem cells, their proliferation and terminal differentiation. The link between the initial inflammation and cell commitment is not yet well established but appears as a potential key factor in the reparative process. Either the release of cytokines due to inflammatory events activates resident stem (progenitor) cells, or inflammatory cells or pulp fibroblasts undergo a phenotypic conversion into osteoblast/odontoblast-like progenitors implicated in reparative dentin formation. Activation of antigen-presenting dendritic cells by mild inflammatory processes may also promote osteoblast/odontoblast-like differentiation and expression of ECM molecules implicated in mineralization. Recognition of bacteria by specific odontoblast and fibroblast membrane receptors triggers an inflammatory and immune response within the pulp tissue that would also modulate the repair process. PMID:18602009

Regeneration of dental pulp/dentine complex with a three-dimensional and scaffold-free stem-cell sheet-derived pellet.

PubMed

Na, Sijia; Zhang, Hao; Huang, Fang; Wang, Weiqi; Ding, Yin; Li, Dechao; Jin, Yan

2016-03-01

Dental pulp/dentine complex regeneration is indispensable to the construction of biotissue-engineered tooth roots and represents a promising approach to therapy for irreversible pulpitis. We used a tissue-engineering method based on odontogenic stem cells to design a three-dimensional (3D) and scaffold-free stem-cell sheet-derived pellet (CSDP) with the necessary physical and biological properties. Stem cells were isolated and identified and stem cells from root apical papilla (SCAPs)-based CSDPs were then fabricated and examined. Compact cell aggregates containing a high proportion of extracellular matrix (ECM) components were observed, and the CSDP culture time was prolonged. The expression of alkaline phosphatase (ALP), dentine sialoprotein (DSPP), bone sialoprotein (BSP) and runt-related gene 2 (RUNX2) mRNA was higher in CSDPs than in cell sheets (CSs), indicating that CSDPs have greater odonto/osteogenic potential. To further investigate this hypothesis, CSDPs and CSs were inserted into human treated dentine matrix fragments (hTDMFs) and transplanted into the subcutaneous space in the backs of immunodeficient mice, where they were cultured in vivo for 6 weeks. The root space with CSDPs was filled entirely with a dental pulp-like tissue with well-established vascularity, and a continuous layer of dentine-like tissue was deposited onto the existing dentine. A layer of odontoblast-like cells was found to express DSPP, ALP and BSP, and human mitochondria lined the surface of the newly formed dentine-like tissue. These results clearly indicate that SCAP-CSDPs with a mount of endogenous ECM have a strong capacity to form a heterotopic dental pulp/dentine complex in empty root canals; this method can be used in the fabrication of bioengineered dental roots and also provides an alternative treatment approach for pulp disease. Copyright © 2013 John Wiley & Sons, Ltd.

Complications and survival rates of teeth after dental trauma over a 5-year period.

PubMed

Bücher, Katharina; Neumann, Claudia; Thiering, Elisabeth; Hickel, Reinhard; Kühnisch, Jan

2013-06-01

The purpose of this study was to evaluate whether the current guidelines of the International Association of Dental Traumatology (IADT) for emergency care of traumatised teeth result in lower complication rates. Therapeutic strategies of 361 dental injuries in 291 patients treated at a university dental hospital over a 5-year period were investigated by evaluating the patients' records. Adherence to the guidelines of the IADT (Flores et al. Dent Traumatol 17:1-4, 2001; 49-52, 2001; 97-102, 2001; 145-148, 2001; and 193-196, 2001; Flores et al. Dent Traumatol 23:66-71, 2007; 130-136, 2007; and 196-202, 2007) was evaluated. Complications were also recorded according to the patients' records and analysed relative to the treatment and injury pattern. During follow-up visits, the teeth were inspected regarding pulp vitality and overall function of the injured tooth. The Kaplan-Meier survival analysis of pulps and teeth was performed for different injury categories. The majority of injuries (322/361; 89.2 %) were treated according to the guidelines. When IADT guidelines were followed, complication rates were significantly lower than for cases treated without adherence to the guidelines. The most frequent complication was the loss of restoration, followed by pulp necrosis, abnormal mobility, and tooth loss. The overall survival analysis showed that in the permanent dentition, the loss of pulp vitality and tooth occurs within the first 6 months but may also occur later. The results of this study indicate that traumatised teeth that were treated according to the recommendations had a lower complication rate. In addition, the majority of pulp necrosis and tooth losses in the permanent dentition occurred within the first 6 months after trauma. These results indicate that early follow-up visits are essential to promptly treat complications. Adherence to the IADT guidelines for treatment of dental trauma may lead to more favourable outcomes when compared to cases treated without compliance to the guidelines.

Pulp tissue in sex determination: A fluorescent microscopic study

PubMed Central

Nayar, Amit; Singh, Harkanwal Preet; Leekha, Swati

2014-01-01

Aims: To determine and compare the reliability of pulp tissue in determination of sex and to analyze whether caries have any effect on fluorescent body test. Materials and Methods: This study was carried on 50 maxillary and mandibular teeth (25 male teeth and 25 female teeth), which were indicated for extraction. The teeth are categorized into 5 groups, 10 each (5 from males and 5 from females) on the basis of caries progression. The pulp cells are stained with quinacrine hydrochloride and observed with fluorescent microscope for fluorescent body. Gender is determined by identification of Y chromosome fluorescence in dental pulp. Results: Fluorescent bodies were found to be more in sound teeth in males as the caries increase the mean percentage of fluorescent bodies observed decreases in males. We also observed the fluorescent spots in females, and the value of the spot increases in female as the caries progresses, thereby giving false positive results in females. Conclusion: Sex determination by fluorescent staining of the Y chromosome is a reliable technique in teeth with healthy pulps or caries with enamel or up to half way of dentin. Teeth with caries involving pulp cannot be used for sex determination. PMID:25125912

The radiographic visibility of the root pulp of the third lower molar as an age marker.

PubMed

Pérez-Mongiovi, Daniel; Teixeira, Alexandra; Caldas, Inês Morais

2015-09-01

The aim of this work was to determine the usefulness of the visibility of the dental pulp in lower third molars in forensic age estimation. Dental pulp visibility on lower third molars was assessed using a sample of 487 orthopantomograms. Intra and inter-observer agreement was determined using the Cohen's kappa test. A descriptive analysis of the stages according to age was done. The relationship between age and stage attainment was assessed using Chi square test and the strength and direction of the linear relationship between pulp visualization stage and chronological age was evaluated using Spearman rank order correlation (rho). Equations for predicting an age above 21 years were developed using logistic regression. The level of significance was defined at p < 0.05. The relationship between age and stage attainment had statistical significance for both sexes (p < 0.001). There was a medium positive correlation between the two variables for both genders (Spearman ρ = 0.420, p < 0.001 and Spearman ρ = 0.454, p < 0.001, for males and females respectively). The model built for age estimation successfully predicted age over 21 in 96.2% of the females and in 96.9% of the males. However, only 19.6 and 27.0% of predictions were accurate for the group that was younger than 21, for females and males, respectively. The accuracy of predictions for the group younger than 21 years of age was low, meaning that this methodology may not be suitable for age estimation. Still, stage 3 alone proved to be a suitable age marker for determining an age over 21 years.

Pulp Calcification in Traumatized Primary Teeth - Classification, Clinical And Radiographic Aspects.

PubMed

Mello-Moura, Anna Carolina Volpi; Santos, Ana Maria Antunes; Bonini, Gabriela Azevedo Vasconcelos Cunha; Zardetto, Cristina Giovannetti Del Conte; Moura-Netto, Cacio; Wanderley, Marcia Turolla

The aim of this study was to standardize the nomenclature of pulp alteration to pulp calcification (PC) and to classify it according to type, quantity and location, as well as relate it to clinical and radiographic features. The dental records of 946 patients from the Research and Clinical Center for Dental Trauma in Primary Teeth were studied. Two hundred and fifty PC-traumatized upper deciduous incisors were detected. According to radiographic analysis of the records, 62.5% showed diffuse calcification, 36.3% tube-like calcification, and 1.2% concentric calcification. According to the extension of pulp calcification, the records showed: 80% partial calcification, 17.2% total coronal calcification and partial radicular calcification, and 2.8 % total coronal and radicular calcification. As for location, only 2.4% were on the coronal pulp, 5.2% on the radicular pulp and 92.4% on both radicular and coronal pulp. Regarding coronal discoloration, 54% were yellow and 2% gray. In relation to periradicular changes, 10% showed widened periodontal ligament space, 3.1% internal resorption, 10% external resorption, 10.4% periapical bone rarefaction. Since PC is a general term, it is important to classify it and correlate it to clinical and radiographic changes, in order to establish the correct diagnosis, treatment and prognosis of each case.

A preliminary report on histological outcome of pulpotomy with endodontic biomaterials vs calcium hydroxide

PubMed Central

Peimani, Ali; Asgary, Saeed

2013-01-01

Objectives The purpose of the study was to evaluate human dental pulp response to pulpotomy with calcium hydroxide (CH), mineral trioxide aggregate (MTA), and calcium enriched mixture (CEM) cement. Materials and Methods A total of nine erupted third molars were randomly assigned to each pulpotomy group. The same clinician performed full pulpotomies and coronal restorations. The patients were followed clinically for six months; the teeth were then extracted and prepared for histological assessments. The samples were blindly assessed by an independent observer for pulp vitality, pulp inflammation, and calcified bridge formation. Results All patients were free of clinical signs/symptoms of pulpal/periradicular diseases during the follow up period. In CH group, one tooth had necrotic radicular pulp; other two teeth in this group had vital uninflamed pulps with complete dentinal bridge formation. In CEM cement and MTA groups all teeth had vital uninflamed radicular pulps. A complete dentinal bridge was formed beneath CEM cement and MTA in all roots. Odontoblast-like cells were present beneath CEM cement and MTA in all samples. Conclusions This study revealed that CEM cement and MTA were reliable endodontic biomaterials in full pulpotomy treatment. In contrast, the human dental pulp response to CH might be unpredictable. PMID:24303358

Regeneration of dental pulp by stem cells.

PubMed

Nakashima, M; Iohara, K

2011-07-01

Angiogenesis/vasculogenesis and neurogenesis are essential for pulp regeneration. Two subfractions of side-population (SP) cells, CD31(-)/CD146(-) SP cells and CD105(+) cells with angiogenic and neurogenic potential, were isolated by flow cytometry from canine dental pulp. In an experimental model of mouse hindlimb ischemia, transplantation of these cell populations resulted in an increase in blood flow, including high-density capillary formation. In a model of rat cerebral ischemia, stem cell transplantations enhanced neuronal regeneration and recovery from motor disability. Autologous transplantation of the CD31(-)/CD146(-) SP cells into an in vivo model of amputated pulp resulted in complete regeneration of pulp tissue with vascular and neuronal processes within 14 days. The transplanted cells expressed pro-angiogenic factors, implying trophic action on endothelial cells. Autologous transplantation of CD31(-)/CD146(-) SP cells or CD105(+) cells with stromal-cell-derived factor-1 (SDF-1) into root canals after whole pulp removal of mature teeth resulted in complete regeneration of pulp replete with nerves and vasculature by day 14, followed by dentin formation along the dentinal wall by day 35. Therefore, the potential utility of fractionated SP cells and CD105(+) cells in angiogenesis and neurogenesis was demonstrated by treatment of limb and cerebral ischemia following pulpotomy and pulpectomy.

Principles of endodontic therapy.

PubMed

Lobprise, H B

1993-08-01

Endodontics is that branch of dentistry concerned with the treatment of damaged or diseased dental pulp. Veterinarians are now being asked to preserve tooth function and structure rather than to extract injured or diseased teeth. A variety of instruments are available that facilitate endodontic treatment. Endodontic treatment involves preparation (filing), sterilization, and obturation (filling) of the pulp cavity. Properly performed, endodontic therapy can effectively preserve dental structure and function. Complications of endodontic therapy will be discussed in "Problem Solving in Veterinary Endodontics" on page 165 in this issue.

Redefining the potential applications of dental stem cells: An asset for future

PubMed Central

Rai, Shalu; Kaur, Mandeep; Kaur, Sandeep; Arora, Sapna Panjwani

2012-01-01

Recent exciting discoveries isolated dental stem cells from the pulp of the primary and permanent teeth, from the periodontal ligament, and from associated healthy tissues. Dental pulp stem cells (DPSCs) represent a kind of adult cell colony which has the potent capacity of self-renewing and multilineage differentiation. Stem cell-based tooth engineering is deemed as a promising approach to the making of a biological tooth (bio-tooth) or engineering of functional tooth structures. Dental professionals have the opportunity to make their patients aware of these new sources of stem cells that can be stored for future use as new therapies are developed for a range of diseases and injuries. The aim of this article is to review and understand how dental stem cells are being used for regeneration of oral and conversely nonoral tissues. A brief review on banking is also done for storing of these valuable stem cells for future use. PMID:23716933

Isolation and evaluation of dental pulp stem cells from teeth with advanced periodontal disease.

PubMed

Derakhshani, Ali; Raoof, Maryam; Dabiri, Shahriar; Farsinejad, Ali Reza; Gorjestani, Hedayat; Yaghoobi, Mohammad Mehdi; Shokouhinejad, Noushin; Ehsani, Maryam

2015-04-01

Successful isolation of mesenchymal stem cells from waste tissues might be extremely promising for developing stem cell-based therapies. This study aimed to explore whether cells retrieved from teeth extracted due to advanced periodontal disease present mesenchymal stem cell-like properties. Pulp cells were isolated from 15 intact molars and 15 teeth with advanced periodontal disease. Cell proliferation and markers of mesenchymal stem cells were evaluated. Based on the RT-PCR and agarose gel electrophoresis, nucleostemin, Oct-4 and jmj2c, but not Nanog, were expressed in undifferentiated mesenchymal stem cells of both groups. Interestingly, diseased pulp exhibited higher gene expressions although it was not statistically significant. The average percentage of BrdU positive cells in the diseased group (84.4%, n = 5) was significantly higher than that of the control group (65.4%, n = 5) (t-test, P = 0.001). Our results indicate the successful isolation of mesenchymal stem cells from the pulp tissue of hopeless periodontally involved teeth.

Stimulation of interleukin-1 beta production of human dental pulp cells by Porphyromonas endodontalis lipopolysaccharide.

PubMed

Hosoya, S; Matsushima, K

1997-01-01

IL-1 beta is synthesized as an inactive precursor, which is subsequently processed by IL-1 beta converting enzyme (ICE) and found extracellularly as a mature biologically active polypeptide. Also, IL-1 beta has been detected in necrotic and inflamed dental pulp. We examined the IL-1 beta production in human dental pulp (HDP) cells treated with lipopolysaccharide (LPS) from Porphyromonas endodontalis (P. e.) isolated from root canals and radicular cyst fluids. We demonstrated that P. e. LPS stimulated IL-1 beta release from HDP cells in a time- and dose-dependent manner. However, ICE activity was not increased by P. e. LPS. Northern blot hybridization analysis revealed that the IL-1 beta mRNA level in HDP cells was increased by P. e. LPS. These results suggest that stimulation of IL-1 beta release from HDP cells by P. e. LPS may have an important role in the progression of inflammation in pulpal and periapical disease.

Human dental pulp stem cell adhesion and detachment in polycaprolactone electrospun scaffolds under direct perfusion

PubMed Central

Paim, A.; Braghirolli, D.I.; Cardozo, N.S.M.; Pranke, P.; Tessaro, I.C.

2018-01-01

Cell adhesion in three-dimensional scaffolds plays a key role in tissue development. However, stem cell behavior in electrospun scaffolds under perfusion is not fully understood. Thus, an investigation was made on the effect of flow rate and shear stress, adhesion time, and seeding density under direct perfusion in polycaprolactone electrospun scaffolds on human dental pulp stem cell detachment. Polycaprolactone scaffolds were electrospun using a solvent mixture of chloroform and methanol. The viable cell number was determined at each tested condition. Cell morphology was analyzed by confocal microscopy after various incubation times for static cell adhesion with a high seeding density. Scanning electron microscopy images were obtained before and after perfusion for the highest flow rate tested. The wall pore shear stress was calculated for all tested flow rates (0.005–3 mL/min). An inversely proportional relationship between adhesion time with cell detachment under perfusion was observed. Lower flow rates and lower seeding densities reduced the drag of cells by shear stress. However, there was an operational limit for the lowest flow rate that can be used without compromising cell viability, indicating that a flow rate of 0.05 mL/min might be more suitable for the tested cell culture in electrospun scaffolds under direct perfusion. PMID:29590258

[Expression of OPG/RANK/RANKL in the rat dental pulp tissue of periodontitis combined with vascular calcification and its clinical significance].

PubMed

Pan, Ke-Qing; Zhang, Peng-Mei; Deng, Jing; Lou, Xiu-Xiu; Meng, Yun; Liu, Gui-Rong

2016-08-01

To study the expression and possible role of OPG/RANK/RANKLin the rat dental pulp of periodontitis combined with vascular calcification. Thirty-six male Wister rats were randomly divided into 4 groups: control group(group C), periodontitis group(group CP), vascular calcification group(group VDN) and compound group(group CP+VDN). Each group underwent corresponding management to establish animal model. When the model was successful, the maxillae including molars were sectioned, pulp tissue was examined by H-E staining; Immunohistochemical staining method was used to evaluate the expression and ratio of OPG and RANKL in pulp tissues. Statistical analysis was carried out using SPSS 19.0 software package. The pulp tissue of group CP, VDN, CP+VDN showed varied degrees of damage, neutrophil infiltration, pulp vascular congestion, odontoblasts vacuolar changes, pulp necrosis by H-E staining, and the changes in CP+VDN group was the most significant, followed by CP group, VDN group. Immunohistochemistry showed OPG in pulp tissues in group CP, VDN, CP+VDN were significantly lower than that in normal group (P<0.05), and the expression in group CP+VDN was the least;Expression of RANKL in pulp tissues in group CP, VDN, CP+VDN were significantly higher than that in normal group(P<0.05)，and the expression in group CP+VDN was the highest. The ratio of OPG/RANKL in normal group was the highest, and the ratio in CP+VDN group was the lowest. Periodontitis and vascular calcification can damage the pulp tissue, periodontitis compound with vascular calcification may aggravate the injury; OPG/RANKL/RANK system may play an important role in pulp tissue injury.

Angiogenic mechanisms of human dental pulp and their relationship with substance P expression in response to occlusal trauma.

PubMed

Caviedes-Bucheli, J; Gomez-Sosa, J F; Azuero-Holguin, M M; Ormeño-Gomez, M; Pinto-Pascual, V; Munoz, H R

2017-04-01

Angiogenesis is the formation of new blood vessels based on a pre-existing vasculature. It comprises two processes, sprouting of endothelial cells and the division of vessels due to abnormal growth of the microvasculature. It has been demonstrated that substance P (SP) can induce angiogenesis either by modulating endothelial cell growth (direct mechanism) or by attracting cells with angiogenic potential to the injury site (indirect mechanism). Therefore, the purpose of this article is to review the angiogenic mechanisms that regulate mineralized tissue formation in human dental pulp tissue and their relationship with SP expression as a defence response to stimuli such as the masticatory function and occlusal trauma. Articles included in this review were searched in PubMed, Scopus and ISI Web of Science databases, combining the following keywords: human dentine pulp, angiogenesis, angiogenic growth factors, neuropeptides, substance P, neurogenic inflammation, dentine matrix, dentinogenesis, occlusal trauma and dental occlusion. It is concluded that human dental pulp tissue responds to occlusal trauma and masticatory function with a neurogenic inflammatory phenomenon in which SP plays an important role in the direct and indirect mechanisms of angiogenesis by the action evoked via NK1 receptors at different cells, such as fibroblasts, endothelial and inflammatory cells, leading to new blood vessel formation which are needed to stimulate mineralized tissue formation as a defence mechanism. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Effects of combining CBCT technology with visual root canal recurrence in treatment of elderly patients with dental pulp disease.

PubMed

Cui, J-J; Peng, B; Lin, W

2017-03-01

The aim of this study is to analyze the effects of combining cone beam computed tomography (CBCT) technology with visual root canal recurrence in the treatment of elderly patients with dental pulp disease. 56 cases of elderly patients with dental pulp disease were contiguously selected, and randomly divided into the control group (70 teeth from 27 patients) and the observation group (77 teeth from the rest 29 patients). We adopted CBCT technology combined with conventional root canal therapy in control group and CBCT technology combined with visual root canal recurrence in observation group to compare the clinical effects. It was found that there was no statistical difference in duration of operation between the two groups (p>0.05). The operation times and the VAS during and after operation of the observation group were significantly less than that of the control group (p<0.05). The duration of follow-up of the two groups was both about 18 months. Successful rates of treatment for 6 months and by the end of follow-up visit in the observation group were both significantly higher than those in the control group (p<0.05). The correct filling rate, good filling rate and fair filling rate in the observation group were significantly higher than those of the control group (p<0.05). CBCT technology combined with visual root canal recurrence can significantly improve the near and long-term treatment effects of elderly patients with dental pulp disease.

Correlation between Fibrillin-1 Degradation and mRNA Downregulation and Myofibroblast Differentiation in Cultured Human Dental Pulp Tissue

PubMed Central

Yoshiba, Nagako; Yoshiba, Kunihiko; Ohkura, Naoto; Takei, Erika; Edanami, Naoki; Oda, Youhei; Hosoya, Akihiro; Nakamura, Hiroaki; Okiji, Takashi

2015-01-01

Myofibroblasts and extracellular matrix are important components in wound healing. Alpha-smooth muscle actin (α-SMA) is a marker of myofibroblasts. Fibrillin-1 is a major constituent of microfibrils and an extracellular-regulator of TGF-β1, an important cytokine in the transdifferentiation of resident fibroblasts into myofibroblasts. To study the correlation between changes in fibrillin-1 expression and myofibroblast differentiation, we examined alterations in fibrillin-1 and α-SMA expression in organotypic cultures of dental pulp in vitro. Extracted healthy human teeth were cut to 1-mm-thick slices and cultured for 7 days. In intact dental pulp, fibrillin-1 was broadly distributed, and α-SMA was observed in pericytes and vascular smooth muscle cells. After 7 days of culture, immunostaining for fibrillin-1 became faint concomitant with a downregulation in its mRNA levels. Furthermore, fibroblasts, odontoblasts and Schwann cells were immunoreactive for α-SMA with a significant increase in α-SMA mRNA expression. Double immunofluorescence staining was positive for pSmad2/3, central mediators of TGF-β signaling, and α-SMA. The administration of inhibitors for extracellular matrix proteases recovered fibrillin-1 immunostaining; moreover, fibroblasts lost their immunoreactivity for α-SMA along with a downregulation in α-SMA mRNA. These findings suggest that the expression of α-SMA is TGF-β1 dependent, and fibrillin-1 degradation and downregulation might be implicated in the differentiation of myofibroblasts in dental pulp wound healing. PMID:25805839

Ulex europaeus agglutinin-I binding to dental primary afferent projections in the spinal trigeminal complex combined with double immunolabeling of substance P and GABA elements using peroxidase and colloidal gold.

PubMed

Matthews, M A; Hoffmann, K D; Hernandez, T V

1989-01-01

Ulex europaeus agglutinin I (UEA-I) is a plant lectin with an affinity for L-fucosyl residues in the chains of lactoseries oligosaccharides associated with medium- and smaller-diameter dorsal root ganglion neurons and their axonal processes. These enter Lissauer's tract and terminate within the superficial laminae of the spinal cord overlapping projections known to have a nociceptive function. This implies that the surface coatings of neuronal membranes may have a relationship with functional modalities. The present investigation further examined this concept by studying a neuronal projection with a nociceptive function to determine whether fucosyl-lactoseries residues were incorporated in its primary afferent terminals. Transganglionic transport of horseradish peroxidase (HRP) following injection into tooth pulp chambers was employed to demonstrate dental pulp terminals in the trigeminal spinal complex, while peroxidase and fluorescent tags were used concomitantly to stain for UEA-I. Double immunolabeling for substance P (SP) and gamma-aminobutyric acid (GABA) using peroxidase and colloidal gold allowed a comparison of the distribution of a known excitatory nociceptive transmitter with that of UEA-I binding in specific subnuclei. Synaptic interrelationships between UEA-I positive dental pulp primary afferent inputs and specific inhibitory terminals were also examined. SP immunoreactivity occurred in laminae I and outer lamina II (IIo) of subnucleus caudalis (Vc) and in the ventrolateral and lateral marginal region of the caudal half of subnucleus interpolaris (Vi), including the periobex area in which Vi is slightly overlapped on its lateral aspect by cellular elements of Vc. The adjacent interstitial nucleus (IN) also showed an intense immunoreactivity for this peptide antibody. UEA-I binding displayed a similar distribution pattern in both Vc and Vi, but extended into lamina IIi and the superficial part of Lamina III in Vc. Dental pulp terminals were found to have a comparable distribution; however, many extended into the dorsal portion of the caudal half of Vi and the ventromedial quadrant of rostral Vi. Electron-microscopic analysis showed that transganglionically labeled dental pulp terminals contained ovoid, complex membrane-bound vacuoles laden with transported HRP. The preterminal axon and synaptic membranes of those dental pulp terminals located in zones of Vc and Vi displaying an affinity for UEA-I were usually characterized by a patchy, electron-dense coating of the peroxidase tag. SP was demonstrated ultrastructurally with Protein-A colloidal gold (3-nm particles), whereas GABA immunoreactivity was revealed by the avidin-biotin-peroxidase method.(ABSTRACT TRUNCATED AT 400 WORDS)

Dental ablation with 1064 nm, 500 ps, Diode pumped solid state laser: A preliminary study.

PubMed

Sozzi, Michele; Fornaini, Carlo; Cucinotta, Annamaria; Merigo, Elisabetta; Vescovi, Paolo; Selleri, Stefano

2013-01-01

The Er:YAG laser in conservative dentistry is. good alternative to conventional instruments. Though several studies show the advantages of these devices, some drawbacks and unsolved problems are still present, such as the cost of the device and the large dimensions of the equipment. In the present study, the effectiveness of dental surface ablation with a picosecond infrared diode-pumped solid-state (DPSS) laser was investigated. In vitro tests on extracted human teeth were carried out, with assessment of the ablation quality in the tooth and thermal increase inside the pulp chamber. A solid-state picosecond laser was used for the experiments. The samples were exposed to laser energy at 1064 nm at a frequency of 30 kHz and a 500 ps pulse width. The target teeth were cooled during exposures. The internal temperature of the pulp chamber was monitored with. thermocouple. Optical microscope images showed effective ablation with the absence of carbonisation and micro-cracks. The cooling maintained the temperature rise in the pulp chamber below the permitted 5.5°C. The main problem with the use of lasers in dentistry when teeth are the target is the heat generated in the pulp chamber of the target teeth. With lasers operating in the femtosecond mode, a better management of the internal temperature is possible, but is offset by the high cost of such devices. With the ps domain system used in the present study together with cooling using chilled water, effective and clean ablation could be achieved with a controlled thermal effect in the pulp chamber. In this preliminary study with a picosecond domain DPSS laser using water cooling for the target, effective hard tissue ablation was achieved keeping the thermal increase in the pulp within the permitted range. The results suggest that this system could be used in clinical practice with appropriate modifications.

Stage-specific effects of FGF2 on the differentiation of dental pulp cells

PubMed Central

Sagomonyants, Karen; Mina, Mina

2015-01-01

Dentinogenesis is a complex and multistep process, which is regulated by various growth factors, including members of the Fibroblast Growth Factor (FGF) family. Both positive and negative effects of FGFs on dentinogenesis have been reported but the underlying mechanisms of these conflicting results are still unclear. To gain better insight into the role of FGF2 in dentinogenesis, we used dental pulp cells from various transgenic mice, in which fluorescent protein expression identifies cells at different stages of odontoblast differentiation. Our results showed that continuous exposure of pulp cells to FGF2 inhibited mineralization and revealed both stimulatory and inhibitory effects of FGF2 on expression of markers of dentinogenesis and various transgenes. During the proliferation phase of in vitro growth FGF2 increased expression of markers of dentinogenesis and the percentages of DMP1-GFP+ functional odontoblasts and DSPP-Cerulean+ odontoblasts. Additional exposure to FGF2 during the differentiation/mineralization phase of in vitro growth decreased the extent of mineralization, expression of markers of dentinogenesis, and expression of DMP1-GFP and DSPP-Cerulean transgenes. Recovery experiments showed that the inhibitory effects of FGF2 on dentinogenesis were related to the blocking of differentiation of cells into mature odontoblasts. These observations together showed stage-specific effects of FGF2 on dentinogenesis by dental pulp cells and provide critical information for the development of improved treatments for vital pulp therapy and dentin regeneration. PMID:25823776

Intrapulpal Temperature Increases Caused by 445-nm Diode Laser-Assisted Debonding of Self-Ligating Ceramic Brackets During Simulated Pulpal Fluid Circulation.

PubMed

Stein, Steffen; Wenzler, Johannes; Hellak, Andreas; Schauseil, Michael; Korbmacher-Steiner, Heike; Braun, Andreas

2018-04-01

This study investigated temperature increases in dental pulp resulting from laser-assisted debonding of ceramic brackets using a 445-nm diode laser. Eighteen ceramic brackets were bonded in standardized manner to 18 caries-free human third molars. Pulpal fluid circulation was simulated by pumping distilled water at 37°C through the pulp chamber. The brackets were irradiated with a 445-nm diode laser. Temperatures were measured using a thermal camera at points P1 (center of the pulp) and P2 (in the hard dental tissue) at the baseline (T0), at the start and end of laser application (T1 and T2), and the maximum during the sequence (T max ). Significant differences in the temperatures measured at P1 and P2 were observed among T0, T1, T2, and T max . Significant increases in temperature were noted at points P1 and P2, between T1 and T2, T1 and T max , and T2 and T max . The maximum P2 values were significantly higher than at P1. The maximum temperature increase measured in the pulp was 2.23°C, lower than the critical threshold of 5.5°C. On the basis of the laser settings used, there is no risk to the vitality of dental pulp during laser-assisted debonding of ceramic brackets with a 445-nm diode laser.

Dental age estimation employing CBCT scans enhanced with Mimics software: Comparison of two different approaches using pulp/tooth volumetric analysis.

PubMed

Asif, Muhammad Khan; Nambiar, Phrabhakaran; Mani, Shani Ann; Ibrahim, Norliza Binti; Khan, Iqra Muhammad; Sukumaran, Prema

2018-02-01

The methods of dental age estimation and identification of unknown deceased individuals are evolving with the introduction of advanced innovative imaging technologies in forensic investigations. However, assessing small structures like root canal volumes can be challenging in spite of using highly advanced technology. The aim of the study was to investigate which amongst the two methods of volumetric analysis of maxillary central incisors displayed higher strength of correlation between chronological age and pulp/tooth volume ratio for Malaysian adults. Volumetric analysis of pulp cavity/tooth ratio was employed in Method 1 and pulp chamber/crown ratio (up to cemento-enamel junction) was analysed in Method 2. The images were acquired employing CBCT scans and enhanced by manipulating them with the Mimics software. These scans belonged to 56 males and 54 females and their ages ranged from 16 to 65 years. Pearson correlation and regression analysis indicated that both methods used for volumetric measurements had strong correlation between chronological age and pulp/tooth volume ratio. However, Method 2 gave higher coefficient of determination value (R2 = 0.78) when compared to Method 1 (R2 = 0.64). Moreover, manipulation in Method 2 was less time consuming and revealed higher inter-examiner reliability (0.982) as no manual intervention during 'multiple slice editing phase' of the software was required. In conclusion, this study showed that volumetric analysis of pulp cavity/tooth ratio is a valuable gender independent technique and the Method 2 regression equation should be recommended for dental age estimation. Copyright © 2018 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

The in vitro and in vivo influence of 4-META/MMA-TBB resin components on dental pulp tissues.

PubMed

Inoue, T; Miyakoshi, S; Shimono, M

2001-08-01

The purpose of this study was to qualitate the penetration of the major components of 4-META/MMA-TBB adhesive resin (4-META resin) and to characterize their influence on the in vitro and in vivo wound healing of dental pulp tissues. Fresh 4-META resin was applied to rabbit mesentery; its components penetrated the mesentery to form three of layers, depending on the amounts of monomer components in the tissue. The superficial layer was a soft-tissue hybrid layer (STHL), the intermediate layer contained small particles of polymerized 4-META resin, while the deepest layer contained unpolymerized monomer components including MMA and butanol, which were detected by gas chromatography (GC). To characterize the in vivo effects of the deepest layer, we immersed the pulp tissue in MMA or in 5% 4-META/MMA and autotransplanted it to placement beneath a rabbit kidney capsule. The MMA-immersed pulp was positive for osteocalcin and presented osteodentin formation at 7 days, as did the untreated control pulp tissue. In contrast, the 5% 4-META/MMA-immersed pulp collapsed into the cell-deficient fibrous connective tissue, with slight calcification by 7 days and less osteodentin formation at 14 days. Analysis of these data suggests that MMA does not inhibit osteogenic activity of pulp tissue, while 5% 4-META/MMA does inhibit osteogenic activity to some extent.

Interferon-gamma improves impaired dentinogenic and immunosuppressive functions of irreversible pulpitis-derived human dental pulp stem cells

PubMed Central

Sonoda, Soichiro; Yamaza, Haruyoshi; Ma, Lan; Tanaka, Yosuke; Tomoda, Erika; Aijima, Reona; Nonaka, Kazuaki; Kukita, Toshio; Shi, Songtao; Nishimura, Fusanori; Yamaza, Takayoshi

2016-01-01

Clinically, irreversible pulpitis is treated by the complete removal of pulp tissue followed by replacement with artificial materials. There is considered to be a high potential for autologous transplantation of human dental pulp stem cells (DPSCs) in endodontic treatment. The usefulness of DPSCs isolated from healthy teeth is limited. However, DPSCs isolated from diseased teeth with irreversible pulpitis (IP-DPSCs) are considered to be suitable for dentin/pulp regeneration. In this study, we examined the stem cell potency of IP-DPSCs. In comparison with healthy DPSCs, IP-DPSCs expressed lower colony-forming capacity, population-doubling rate, cell proliferation, multipotency, in vivo dentin regeneration, and immunosuppressive activity, suggesting that intact IP-DPSCs may be inadequate for dentin/pulp regeneration. Therefore, we attempted to improve the impaired in vivo dentin regeneration and in vitro immunosuppressive functions of IP-DPSCs to enable dentin/pulp regeneration. Interferon gamma (IFN-γ) treatment enhanced in vivo dentin regeneration and in vitro T cell suppression of IP-DPSCs, whereas treatment with tumor necrosis factor alpha did not. Therefore, these findings suggest that IFN-γ may be a feasible modulator to improve the functions of impaired IP-DPSCs, suggesting that autologous transplantation of IFN-γ-accelerated IP-DPSCs might be a promising new therapeutic strategy for dentin/pulp tissue engineering in future endodontic treatment. PMID:26775677

Retrieval of a periodontally compromised tooth by allogeneic grafting of mesenchymal stem cells from dental pulp: A case report.

PubMed

Hernández-Monjaraz, Beatriz; Santiago-Osorio, Edelmiro; Ledesma-Martínez, Edgar; Alcauter-Zavala, Andrés; Mendoza-Núñez, Víctor Manuel

2018-01-01

Objective To report a case of successful allogeneic grafting of mesenchymal dental pulp stem cells (DPSCs) as preliminary findings in a patient with periodontal disease enrolled into clinical trial ISRCTN12831118. Methods Mesenchymal stem cells from the dental pulp of a deciduous tooth from a 7-year-old donor were separated from the pulp chamber and processed via enzymatic digestion and centrifugation. DPSCs were passaged and cultured on a 35 × 13 mm culture dish in minimum essential medium-alpha, without supplementation. After reaching 80% confluency, 5 x 10 6 allogeneic DPSCs in 250 µl phosphate buffered saline were seeded onto a dry scaffold of lyophilized collagen-polyvinylpyrrolidone sponge placed in the left lower premolar area of a 61-year-old patient with periodontal disease. Surgical access to the lower premolar area was achieved using the flap technique. Results At 3 and 6 months following allogeneic graft, the patient showed no sign of rejection and exhibited decreases in tooth mobility, periodontal pocket depth and bone defect area. Bone mineral density had increased at the graft site. Conclusions Regenerative periodontal therapy using DPSCs of allogeneic origin may be a promising treatment for periodontal disease-induced bone defects.

Odontogenic Differentiation of Human Dental Pulp Stem Cells Stimulated by the Calcium Phosphate Porous Granules

PubMed Central

Nam, Sunyoung; Won, Jong-Eun; Kim, Cheol-Hwan; Kim, Hae-Won

2011-01-01

Effects of three-dimensional (3D) calcium phosphate (CaP) porous granules on the growth and odontogenic differentiation of human dental pulp stem cells (hDPSCs) were examined for dental tissue engineering. hDPSCs isolated from adult human dental pulps were cultured for 3-4 passages, and populated on porous granules. Cell growth on the culture dish showed an ongoing increase for up to 21 days, whereas the growth on the 3D granules decreased after 14 days. This reduction in proliferative potential on the 3D granules was more conspicuous under the osteogenic medium conditions, indicating that the 3D granules may induce the odontogenic differentiation of hDPSCs. Differentiation behavior on the 3D granules was confirmed by the increased alkaline phosphatase activity, up-regulation of odontoblast-specific genes, including dentin sialophosphoprotein (DSPP) and dentin matrix protein 1 (DMP1) by quantitative polymerase chain reaction, and greater level of dentin sialoprotein synthesis by western blot. Moreover, the cellular mineralization, as assessed by Alizarin red S and calcium quantification, was significantly higher in the 3D CaP granules than in the culture dish. Taken all, the 3D CaP porous granules should be useful for dental tissue engineering in combination with hDPSCs by providing favorable 3D substrate conditions for cell growth and odontogenic development. PMID:21772958

Osteoblastic/Cementoblastic and Neural Differentiation of Dental Stem Cells and Their Applications to Tissue Engineering and Regenerative Medicine

PubMed Central

Kim, Byung-Chul; Bae, Hojae; Kwon, Il-Keun; Lee, Eun-Jun; Park, Jae-Hong

2012-01-01

Recently, dental stem and progenitor cells have been harvested from periodontal tissues such as dental pulp, periodontal ligament, follicle, and papilla. These cells have received extensive attention in the field of tissue engineering and regenerative medicine due to their accessibility and multilineage differentiation capacity. These dental stem and progenitor cells are known to be derived from ectomesenchymal origin formed during tooth development. A great deal of research has been accomplished for directing osteoblastic/cementoblastic differentiation and neural differentiation from dental stem cells. To differentiate dental stem cells for use in tissue engineering and regenerative medicine, there needs to be efficient in vitro differentiation toward the osteoblastic/cementoblastic and neural lineage with well-defined and proficient protocols. This would reduce the likelihood of spontaneous differentiation into divergent lineages and increase the available cell source. This review focuses on the multilineage differentiation capacity, especially into osteoblastic/cementoblastic lineage and neural lineages, of dental stem cells such as dental pulp stem cells (DPSC), dental follicle stem cells (DFSC), periodontal ligament stem cells (PDLSC), and dental papilla stem cells (DPPSC). It also covers various experimental strategies that could be used to direct lineage-specific differentiation, and their potential applications in tissue engineering and regenerative medicine. PMID:22224548

Osteoblastic/cementoblastic and neural differentiation of dental stem cells and their applications to tissue engineering and regenerative medicine.

PubMed

Kim, Byung-Chul; Bae, Hojae; Kwon, Il-Keun; Lee, Eun-Jun; Park, Jae-Hong; Khademhosseini, Ali; Hwang, Yu-Shik

2012-06-01

Recently, dental stem and progenitor cells have been harvested from periodontal tissues such as dental pulp, periodontal ligament, follicle, and papilla. These cells have received extensive attention in the field of tissue engineering and regenerative medicine due to their accessibility and multilineage differentiation capacity. These dental stem and progenitor cells are known to be derived from ectomesenchymal origin formed during tooth development. A great deal of research has been accomplished for directing osteoblastic/cementoblastic differentiation and neural differentiation from dental stem cells. To differentiate dental stem cells for use in tissue engineering and regenerative medicine, there needs to be efficient in vitro differentiation toward the osteoblastic/cementoblastic and neural lineage with well-defined and proficient protocols. This would reduce the likelihood of spontaneous differentiation into divergent lineages and increase the available cell source. This review focuses on the multilineage differentiation capacity, especially into osteoblastic/cementoblastic lineage and neural lineages, of dental stem cells such as dental pulp stem cells (DPSC), dental follicle stem cells (DFSC), periodontal ligament stem cells (PDLSC), and dental papilla stem cells (DPPSC). It also covers various experimental strategies that could be used to direct lineage-specific differentiation, and their potential applications in tissue engineering and regenerative medicine.

Artificial dental pulp exposure injury up-regulates antigen-presenting cell-related molecules in rat central nervous system.

PubMed

Kaneko, Tomoatsu; Kaneko, Mitsuhiro; Chokechanachaisakul, Uraiwan; Kawamura, Jun; Kaneko, Reika; Sunakawa, Mitsuhiro; Okiji, Takashi; Suda, Hideaki

2010-03-01

Bacterial infection and resulting inflammation of the dental pulp might not only trigger neuroimmune interactions in this tissue but also sensitize the central nervous system (CNS) such as the thalamus via nociceptive neurons. Thus, immunopathologic changes in the rat thalamus that take place after pulp inflammation were investigated. Pulp exposure was made in mandibular right first molars of 5-week-old Wistar rats. After 24 hours, the thalamus was retrieved and subjected to either immunohistochemistry for class II major histocompatibility complex (MHC) molecules and glial fibrillary acidic protein (GFAP) or mRNA expression analysis of antigen-presenting cell-related molecules and N-methyl-D-aspartate receptor 2D subunit (NR2D) by means of reverse transcription-polymerase chain reaction (RT-PCR) and real-time PCR. At 24 hours after pulp exposure, the density of class II MHC molecule-expressing and GFAP-expressing cells was increased in the contralateral thalamus. Gene expression analysis revealed the up-regulation of class II MHC molecules, CD80, CD83, CD86, and NR2D in the contralateral thalamus, as compared with the ipsilateral thalamus. These results suggest the signal of pulp inflammation induces neuronal activation in the CNS. Copyright (c) 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Amelogenin exons 8 and 9 encoded peptide enhances leucine rich amelogenin peptide mediated dental pulp repair.

PubMed

Huang, Yulei; Goldberg, Michel; Le, Thuan; Qiang, Ran; Warner, Douglas; Witkowska, Halina Ewa; Liu, Haichuan; Zhu, Li; Denbesten, Pamela; Li, Wu

2012-01-01

Amelogenins containing exons 8 and 9 are alternatively spliced variants of amelogenin. Some amelogenin spliced variants have been found to promote pulp regeneration following pulp exposure. The function of the amelogenin spliced variants with the exons 8 and 9 remains unknown. In this study, we synthesized recombinant leucine rich amelogenin peptide (LRAP, A-4), LRAP plus exons 8 and 9 peptide (LRAP 8, 9) or exons 8 and 9 peptide (P89), to determine their effects on odontoblasts. In vivo analyses were completed following the insertion of agarose beads containing LRAP or LRAP 8, 9 into exposed cavity preparations of rat molars. After 8, 15 or 30 days' exposure, the pulp tissues were analyzed for changes in histomorphometry and cell proliferation by PCNA stainings. In vitro analyses included the effects of the addition of the recombinant proteins or peptide on cell proliferation, differentiation and adhesion of postnatal human dental pulp cells (DPCs). These studies showed that in vivo LRAP 8, 9 enhanced the reparative dentin formation as compared to LRAP. In vitro LRAP 8, 9 promoted DPC proliferation and differentiation to a greater extent than LRAP. These data suggest that amelogenin exons 8 and 9 may be useful in amelogenin-mediated pulp repair. Copyright © 2012 S. Karger AG, Basel.

PAR-2 regulates dental pulp inflammation associated with caries.

PubMed

Lundy, F T; About, I; Curtis, T M; McGahon, M K; Linden, G J; Irwin, C R; El Karim, I A

2010-07-01

Protease-activated receptors (PARs) are G-protein-coupled receptors that are activated enzymatically by proteolysis of an N-terminal domain. The cleavage and activation of PARs by serine proteases represent a novel mechanism by which such enzymes could influence the host inflammatory response. The aim of this study was to determine whether PAR-2 expression and activation were increased in dental caries. Using immunohistochemistry, we showed PAR-2 to be localized to pulp cells subjacent to caries lesions, but minimally expressed by healthy pulp tissue. Trypsin and the PAR-2 agonist (PAR2-AP) activated PAR-2 in an in vitro functional assay. Endogenous molecules present in pulp cell lysates from carious teeth specifically activated PAR-2, but those from healthy teeth failed to do so. The activation of PAR-2 in vitro was shown to increase the expression of the pro-inflammatory mediator cyclo-oxygenase-2 (COX-2), providing a mechanism whereby PAR-2 could modulate pulpal inflammation.

LED Curing Lights and Temperature Changes in Different Tooth Sites

PubMed Central

Armellin, E.; Bovesecchi, G.; Coppa, P.; Pasquantonio, G.; Cerroni, L.

2016-01-01

Objectives. The aim of this in vitro study was to assess thermal changes on tooth tissues during light exposure using two different LED curing units. The hypothesis was that no temperature increase could be detected within the dental pulp during polymerization irrespective of the use of a composite resin or a light-curing unit. Methods. Caries-free human first molars were selected, pulp residues were removed after root resection, and four calibrated type-J thermocouples were positioned. Two LED lamps were tested; temperature measurements were made on intact teeth and on the same tooth during curing of composite restorations. The data was analyzed by one-way analysis of variance (ANOVA), Wilcoxon test, Kruskal-Wallis test, and Pearson's χ 2. After ANOVA, the Bonferroni multiple comparison test was performed. Results. Polymerization data analysis showed that in the pulp chamber temperature increase was higher than that without resin. Starlight PRO, in the same condition of Valo lamp, showed a lower temperature increase in pre- and intrapolymerization. A control group (without composite resin) was evaluated. Significance. Temperature increase during resin curing is a function of the rate of polymerization, due to the exothermic polymerization reaction, the energy from the light unit, and time of exposure. PMID:27195282

LED Curing Lights and Temperature Changes in Different Tooth Sites.

PubMed

Armellin, E; Bovesecchi, G; Coppa, P; Pasquantonio, G; Cerroni, L

2016-01-01

Objectives. The aim of this in vitro study was to assess thermal changes on tooth tissues during light exposure using two different LED curing units. The hypothesis was that no temperature increase could be detected within the dental pulp during polymerization irrespective of the use of a composite resin or a light-curing unit. Methods. Caries-free human first molars were selected, pulp residues were removed after root resection, and four calibrated type-J thermocouples were positioned. Two LED lamps were tested; temperature measurements were made on intact teeth and on the same tooth during curing of composite restorations. The data was analyzed by one-way analysis of variance (ANOVA), Wilcoxon test, Kruskal-Wallis test, and Pearson's χ (2). After ANOVA, the Bonferroni multiple comparison test was performed. Results. Polymerization data analysis showed that in the pulp chamber temperature increase was higher than that without resin. Starlight PRO, in the same condition of Valo lamp, showed a lower temperature increase in pre- and intrapolymerization. A control group (without composite resin) was evaluated. Significance. Temperature increase during resin curing is a function of the rate of polymerization, due to the exothermic polymerization reaction, the energy from the light unit, and time of exposure.

Facile synthesis and characterization of novel rapid-setting spherical sub-micron bioactive glasses cements and their biocompatibility in vitro.

PubMed

Li, Yuli; Liang, Qiming; Lin, Cai; Li, Xian; Chen, Xiaofeng; Hu, Qing

2017-06-01

Dental pulp vitality is extremely important for the tooth viability, since it provides nutrition and forms the dentin. Bioactive glasses (BGs) may be promising materials for pulp repair due to their excellent abilities of rapidly bonding to bone and stimulating new bone growth. However, the unsatisfied handling property, low plasticity, and poor rapid-setting property of traditional BGs limit its application in vital pulp therapy. Spherical bioactive glasses (SBGs) exhibited higher osteogenesis and odontogenic differentiation than irregular BGs. This study focuses on the application of SBGs with rapid setting property for dental pulp repair. Here, SBGs with various compositions were successfully synthesized by a sol-gel process using dodecylamine (DDA) served as both a catalyst and a template. The maximum content of CaO in SBGs was about 15%. The non-bridge oxygen amounts of the SiO network and the apatite-forming ability increased with the content proportion of CaO and P 2 O 5 . Bioactive glass pulp capping materials (BGPCMs) were prepared by mixing the SBGs powders and the phosphate buffer solution (PBS). The K 3 CaH(PO 4 ) 2 and hydroxyapatite (HA) formed between SBGs particles as soon as they were mixed with PBS solution. The compressive strengths of fully set BCPCM-2 molded were measured to be 31.76±1.9577MPa after setting for 24h. The K 3 CaH(PO 4 ) 2 and the low crystallinity HA phases at the initial stage of solidification transformed to crystalline HA for 3days, and the compressive strength was still higher than 10MPa. Additionally, SBG-2 with a designed molar composition of 35% SiO 2 , 55% CaO and 10% P 2 O 5 more promoted dental pulp cell proliferation, and could be potential pulp capping applications. Copyright © 2017. Published by Elsevier B.V.

Dental health and treatment needs among children in a tribal community.

PubMed

Viragi, Prashant S; Dwijendra, K S; Kathariya, Mitesh D; Chopra, Kirti; Dadpe, Mahesh V; Madhukar, H S

2013-07-01

To assess the dental health status and treatment needs among children of 'Pardhi' tribal community. A total of 185 children were examined over a period of 2 months using WHO proforma. The statistical software namely SPSS version 15.0 and data was analyzed using Student's t-test and ANOVA test at p < 0.05. The mean score for dft and DMFT was 1.87 ± 1.073 and 2.04 ± 1.564 respectively with males subjects were having comparatively more scores. It was also found significant differences between age groups. Most of the children needed one surface filling, i.e. 29.40%, followed by pulp care and restoration (19.30%), two or more surface fillings (15.60%) and extraction (11.70%). The study subjects were characterized by a lack of dental care services, high prevalence of dental caries and treatment needs. Therefore, implementation of a basic oral health care program for this tribal population is a high priority.

Intra-pulp temperature increase of equine cheek teeth during treatment with motorized grinding systems: influence of grinding head position and rotational speed.

PubMed

Haeussler, Silvia; Luepke, Matthias; Seifert, Hermann; Staszyk, Carsten

2014-02-21

In equine practice, teeth corrections by means of motorized grinding systems are standard procedure. The heat resulting from that treatment may cause irreparable damage to the dental pulp. It has been shown that a 5.5°C temperature rise may cause severe destruction in pulp cells. Hence, the capability to continuously form secondary dentine is lost, and may lead, due to equine-typical occlusal tooth abrasion, to an opening of the pulp cavity.To obtain reliable data on the intra-pulp increase in temperature during corrective treatments, equine cheek teeth (CT) were modified in a way (occlusal surface smoothed, apical parts detached, pulp horns standardized) that had been qualified in own former published studies. All parameters influencing the grinding process were standardized (force applied, initial temperatures, dimensions of pulp horns, positioning of grinding disk, rotational speed). During grinding experiments, imitating real dental treatments, the time span for an intra-pulp temperature increase of 5.5°C was determined. The minimum time recorded for an intra-pulp temperature increase of 5.5°C was 38 s in mandibular CT (buccal grinding, 12,000 rpm) and 70 s in maxillary CT (flat occlusal grinding, 12,000 rpm). The data obtained showed that doubling the rotational speed of the disk results in halving the time span after which the critical intra-pulp temperature increase in maxillary CT is reached. For mandibular CT, the time span even drops by two thirds. The use of standardized hypsodont CT enabled comparative studies of intra-pulp heating during the grinding of occlusal tooth surfaces using different tools and techniques. The anatomical structure of the natural vital hypsodont tooth must be kept in mind, so that the findings of this study do not create a deceptive sense of security with regard to the time-dependent heating of the native pulp.

Intra-pulp temperature increase of equine cheek teeth during treatment with motorized grinding systems: influence of grinding head position and rotational speed

PubMed Central

2014-01-01

Background In equine practice, teeth corrections by means of motorized grinding systems are standard procedure. The heat resulting from that treatment may cause irreparable damage to the dental pulp. It has been shown that a 5.5°C temperature rise may cause severe destruction in pulp cells. Hence, the capability to continuously form secondary dentine is lost, and may lead, due to equine-typical occlusal tooth abrasion, to an opening of the pulp cavity. To obtain reliable data on the intra-pulp increase in temperature during corrective treatments, equine cheek teeth (CT) were modified in a way (occlusal surface smoothed, apical parts detached, pulp horns standardized) that had been qualified in own former published studies. All parameters influencing the grinding process were standardized (force applied, initial temperatures, dimensions of pulp horns, positioning of grinding disk, rotational speed). During grinding experiments, imitating real dental treatments, the time span for an intra-pulp temperature increase of 5.5°C was determined. Results The minimum time recorded for an intra-pulp temperature increase of 5.5°C was 38 s in mandibular CT (buccal grinding, 12,000 rpm) and 70 s in maxillary CT (flat occlusal grinding, 12,000 rpm). The data obtained showed that doubling the rotational speed of the disk results in halving the time span after which the critical intra-pulp temperature increase in maxillary CT is reached. For mandibular CT, the time span even drops by two thirds. Conclusion The use of standardized hypsodont CT enabled comparative studies of intra-pulp heating during the grinding of occlusal tooth surfaces using different tools and techniques. The anatomical structure of the natural vital hypsodont tooth must be kept in mind, so that the findings of this study do not create a deceptive sense of security with regard to the time-dependent heating of the native pulp. PMID:24559121

Decellularized Human Dental Pulp as a Scaffold for Regenerative Endodontics.

PubMed

Song, J S; Takimoto, K; Jeon, M; Vadakekalam, J; Ruparel, N B; Diogenes, A

2017-06-01

Teeth undergo postnatal organogenesis relatively late in life and only complete full maturation a few years after the crown first erupts in the oral cavity. At this stage, development can be arrested if the tooth organ is damaged by either trauma or caries. Regenerative endodontic procedures (REPs) are a treatment alternative to conventional root canal treatment for immature teeth. These procedures rely on the transfer of apically positioned stem cells, including stem cells of the apical papilla (SCAP), into the root canal system. Although clinical success has been reported for these procedures, the predictability of expected outcomes and the organization of the newly formed tissues are affected by the lack of an available suitable scaffold that mimics the complexity of the dental pulp extracellular matrix (ECM). In this study, we evaluated 3 methods of decellularization of human dental pulp to be used as a potential autograft scaffold. Tooth slices of human healthy extracted third molars were decellularized by 3 different methods. One of the methods generated the maximum observed decellularization with minimal impact on the ECM composition and organization. Furthermore, recellularization of the scaffold supported the proliferation of SCAP throughout the scaffold with differentiation into odontoblast-like cells near the dentinal walls. Thus, this study reports that human dental pulp from healthy extracted teeth can be successfully decellularized, and the resulting scaffold supports the proliferation and differentiation of SCAP. The future application of this form of an autograft in REPs can fulfill a yet unmet need for a suitable scaffold, potentially improving clinical outcomes and ultimately promoting the survival and function of teeth with otherwise poor prognosis.

Regeneration of Corneal Epithelium With Dental Pulp Stem Cells Using a Contact Lens Delivery System.

PubMed

Kushnerev, Evgeny; Shawcross, Susan G; Sothirachagan, Shankari; Carley, Fiona; Brahma, Arun; Yates, Julian M; Hillarby, M Chantal

2016-10-01

The corneal epithelium is sloughed off surface of the eye by the action of blinking and is continually replaced by division and maturation of the limbal stem cells (LSCs). In the case of injury or disease, LSCs can be lost or damaged to a point at which the corneal epithelial layer is no longer maintained. leading to LSC deficiencies (LSCDs). When this occurs, the opaque conjunctiva overgrows the anterior surface of the eye, leading to vision impairment or loss. Dental pulp stem cells (DPSCs) are promising candidates as autologous LSC substitutes. In this study, contact lenses (CLs) are used as a novel medical device to deliver DPSCs onto corneal surface to enhance corneal epithelium regeneration. Dental pulp stem cells labeled with green fluorescent Qtracker 525 were seeded onto the pretreated CLs, allowed to adhere, then delivered to debrided human corneas. Expression of KRT3, 12, 13, and 19 was investigated by immunostaining, then standard and confocal microscopy. Dental pulp stem cells were successfully isolated, labeled, and delivered to the corneal surface using CLs. Following removal of CLs, confocal microscopy showed that the DPSCs had migrated onto the cornea. Coexpression of KRT12 and green fluorescent Qtracker 525 confirmed that the DPSCs had transdifferentiated into corneal epithelial progenitors. Delimitation of KRT 19 and green fluorescence provides evidence that Qtracker 525-labeled DPSCs establish a barrier to the invasion of the cornea by conjunctiva. In this study we show that DPSCs, delivered using CLs, can be used to enhance repair and regeneration of the human corneal epithelium.

Drawing Links within Dental Education

ERIC Educational Resources Information Center

Wright, J.

2017-01-01

This study examines results of a practical drawing task given to a cohort of first year dental surgery students at Kings College Dental Institute, London. It compares and relates their success in drilling and removing caries and pulp tissue from a virtual tooth using the hapTEL virtual learning system, with each individuals' drawing skills.…

Comparison of immunodulatory properties of dental pulp stem cells derived from healthy and inflamed teeth.

PubMed

Yazid, Farinawati Binti; Gnanasegaran, Nareshwaran; Kunasekaran, Wijenthiran; Govindasamy, Vijayendran; Musa, Sabri

2014-12-01

The aim of this study was to investigate the immunodulatory properties of dental pulp stem cells derived from healthy (SCD) and inflamed pulp deciduous (SCDIP) tissues. The overall hypothesis is that SCDIP possess equal immune properties with SCD and could be used as an alternative tissue source in regenerative medicine. An intra-oral examination was carried out to assess the status of the pulp tissues and group them according to healthy or inflamed. Primary cells were established from these groups, and basic mesenchymal stem cells (MSC) characterizations were conducted. The expression of human leukocyte antigen (HLA), namely HLA-G, HLA-DR, and HLA-ABC were examined in both cell lines using flow cytometry. We further compared the immunosuppressive effects of SCD and SCDIP on phytohemagglutinin-induced T cell proliferation. Supernatants were tested for cytokine profiling using multiplex array. While SCD exhibited typical MSC characteristics, SCDIP on the other hand, did not. Compared with SCDIP, SCD effectively suppresses mitogen-induced T cells proliferation in a dose-dependent manner, as well as express a higher percentage of HLA-ABC and HLA-G. In addition, levels of several cytokines, such as TNF-α, TNF-β, and IL-2, were drastically suppressed in SCD than SCDIP. Furthermore, a high level of IL-10, an important anti-inflammatory cytokine, was present in SCD compared with SCDIP. These findings suggest that SCDIP is highly dysfunctional in terms of their stemness and immunomodulatory properties. SCDIP is not a viable therapeutic cell source especially when used in graft versus host disease (GvHD) and organ rejection.

Pulpal changes associated with advanced periodontal disease: A histopathological study.

PubMed

Gautam, Siddharth; Galgali, Sushama R; Sheethal, H S; Priya, N S

2017-01-01

Over the past century, the dental literature has consistently reflected a controversy related to the effect of periodontal disease on the dental pulp. Nonetheless, practitioners are of the opinion that teeth having deep periodontal pockets show variable pulpal response, which may necessitate root canal treatment. Thus, this study aimed to evaluate the changes in pulp due to advanced periodontal disease. Forty caries-free teeth affected with severe periodontitis were collected from patients aged between 18 and 55 years. The collected teeth were stored in formalin for 24 h and were then decalcified and examined histologically after staining with hematoxylin and eosin to note the changes that occurred in pulp. Pulpal calcification (52.62%) and partial necrosis of pulp (52.62%) were found to be the most common findings. Inflammation, which was found in 47.38% of the cases, ranged from mild to severe in most sections and was always chronic. Pulp with complete necrosis was seen in 26.32% of cases. Fibrosis and pulpal edema were seen in 36.84% of cases. In the presence of moderate to severe chronic periodontitis, degenerative changes such as inflammation, fibrosis, edema, calcification and necrosis were observed to variable degree.

In vitro effects of ascorbic acid and β-glycerophosphate on human gingival fibroblast cells.

PubMed

Martinez, Elizabeth F; Donato, Tatiani A G; Arana-Chavez, Victor E

2012-10-01

Ascorbic acid (AA) and β-glycerophosphate (βG) are considered in vitro osteogenic factors important to the differentiation of osteoblastic progenitor and dental pulp cells into mineralized tissue-forming cells. So, the present study investigated in vitro if these mineralizing inducible factors (AA and βG) could influence differentiation of human gingival fibroblasts when compared with human pulp cells and osteogenic cells derived from rat calvaria cultured. The expression of osteopontin (OPN) and osteoadherin (OSAD) was analyzed by indirect immunofluorescence, immunocytochemistry as well as Western-blotting. In addition, the main ultrastructural aspects were also investigated. No mineralized matrix formation occurred on gingival fibroblasts induced with AA+βG. On these cells, no expression of OPN and OSAD was observed when compared with pulp cells, pulp cells induced with AA+βG as well as osteogenic cells. Ultrastructure analysis additionally showed that gingival fibroblasts exhibited typical fibroblast morphology with no nodule formation. The present findings showed that AA and βG could not promote a mineralized cell differentiation of human gingival fibroblasts and confirm that human dental pulp cells, as the osteogenic cells, are capable to form a mineralized extracellular. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effects of recombinant dentin sialoprotein in dental pulp cells.

PubMed

Lee, S-Y; Kim, S-Y; Park, S-H; Kim, J-J; Jang, J-H; Kim, E-C

2012-04-01

Dentin sialophosphoprotein (DSPP) is critical for dentin mineralization. However, the function of dentin sialoprotein (DSP), the cleaved product of DSPP, remains unclear. This study aimed to investigate the signal transduction pathways and effects of recombinant human DSP (rh-DSP) on proliferation, migration, and odontoblastic differentiation in human dental pulp cells (HDPCs). The exogenous addition of rh-DSP enhanced the proliferation and migration of HDPCs in dose- and time-dependent manners. rh-DSP markedly increased ALP activity, calcium nodule formation, and levels of odontoblastic marker mRNA. rh-DSP increased BMP-2 expression and Smad1/5/8 phosphorylation, which was blocked by the BMP antagonist, noggin. Furthermore, rh-DSP phosphorylated extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), Akt, and IκB-α, and induced the nuclear translocation of the NF-κB p65 subunit. Analysis of these data demonstrates a novel signaling function of rh-DSP for the promotion of growth, migration, and differentiation in HDPCS via the BMP/Smad, JNK, ERK, MAPK, and NF-κB signaling pathways, suggesting that rh-DSP may have therapeutic utility in dentin regeneration or dental pulp tissue engineering.

Human dental pulp stem cells: from biology to clinical applications.

PubMed

d'Aquino, Riccardo; De Rosa, Alfredo; Laino, Gregorio; Caruso, Filippo; Guida, Luigi; Rullo, Rosario; Checchi, Vittorio; Laino, Luigi; Tirino, Virginia; Papaccio, Gianpaolo

2009-07-15

Dental pulp stem cells (DPSCs) can be found within the "cell rich zone" of dental pulp. Their embryonic origin, from neural crests, explains their multipotency. Up to now, two groups have studied these cells extensively, albeit with different results. One group claims that these cells produce a "dentin-like tissue", whereas the other research group has demonstrated that these cells are capable of producing bone, both in vitro and in vivo. In addition, it has been reported that these cells can be easily cryopreserved and stored for long periods of time and still retain their multipotency and bone-producing capacity. Moreover, recent attention has been focused on tissue engineering and on the properties of these cells: several scaffolds have been used to promote 3-D tissue formation and studies have demonstrated that DPSCs show good adherence and bone tissue formation on microconcavity surface textures. In addition, adult bone tissue with good vascularization has been obtained in grafts. These results enforce the notion that DPSCs can be used successfully for tissue engineering. (c) 2008 Wiley-Liss, Inc.

Effects of pulpotomy using mineral trioxide aggregate on prostaglandin transporter and receptors in rat molars.

PubMed

Ohkura, Naoto; Edanami, Naoki; Takeuchi, Ryosuke; Tohma, Aiko; Ohkura, Mariko; Yoshiba, Nagako; Yoshiba, Kunihiko; Ida-Yonemochi, Hiroko; Ohshima, Hayato; Okiji, Takashi; Noiri, Yuichiro

2017-07-31

Mineral trioxide aggregate (MTA) is a commonly used dental pulp-capping material with known effects in promoting reparative dentinogenesis. However, the mechanism by which MTA induces dentine repair remains unclear. The aim of the present study was to investigate the role of prostaglandin E 2 (PGE 2 ) in dentine repair by examining the localisation and mRNA expression levels of its transporter (Pgt) and two of its receptors (Ep2 and Ep4) in a rat model of pulpotomy with MTA capping. Ep2 expression was detected in odontoblasts, endothelial cells, and nerve fibres in normal and pulpotomised tissues, whereas Pgt and Ep4 were immunolocalised only in the odontoblasts. Moreover, mRNA expression of Slco2a1 (encoding Pgt), Ptger2 (encoding Ep2), and Ptger4 (encoding Ep4) was significantly upregulated in pulpotomised dental pulp and trigeminal ganglia after MTA capping. Our results provide insights into the functions of PGE 2 via Pgt and Ep receptors in the healing dentine/pulp complex and may be helpful in developing new therapeutic targets for dental disease.

DENTAL PULP STEM CELLS AND HUMAN PERIAPICAL CYST MESENCHYMAL STEM CELLS IN BONE TISSUE REGENERATION: COMPARISON OF BASAL AND OSTEOGENIC DIFFERENTIATED GENE EXPRESSION OF A NEWLY DISCOVERED MESENCHYMAL STEM CELL LINEAGE.

PubMed

Tatullo, M; Falisi, G; Amantea, M; Rastelli, C; Paduano, F; Marrelli, M

2015-01-01

Bone regeneration is an interesting field of biomedicine. The most recent studies are aimed to achieve a bone regeneration using mesenchymal stem cells (MSCs) taken from more accessible sites: oral and dental tissues have been widely investigated as a rich accessible source of MSCs. Dental Pulp Stem Cells (DPSCs) and human Periapical Cysts Mesenchymal Stem Cells (hPCy-MSCs) represent the new generation MSCs. The aim of this study is to compare the gene expression of these two innovative cell types to highlight the advantages of their use in bone regeneration. The harvesting, culturing and differentiating of cells isolated from dental pulp as well as from periapical cystic tissue were carried out as described in previously published reports. qRT-PCR analyses were performed on osteogenic genes in undifferentiated and osteogenic differentiated cells of DPSC and hPCy-MSC lineage. Real-time RT-PCR data suggested that both DPSCs and hPCy-MSCs cultured in osteogenic media are able to differentiate into osteoblast/odontoblast-like cells: however, some differences indicated that DPSCs seem to be directed more towards dentinogenesis, while hPCy-MSCs seem to be directed more towards osteogenesis.

High proportions of Staphylococcus epidermidis in dental caries harbor multiple classes of antibiotics resistance, significantly increase inflammatory interleukins in dental pulps.

PubMed

Devang Divakar, Darshan; Muzaheed; Aldeyab, Sultan Salem; Alfawaz, Sara A; AlKheraif, Abdulaziz Abdullah; Ahmed Khan, Aftab

2017-08-01

Staphylococcus epidermidis is one of most prevalent in dental caries or dental pulp which has the capability of horizontal genetic transfer between different bacterial species in the oropharynx, suggesting that it may evolve with the dissemination of resistant determinants, This study was performed to molecularly characterize and differentiate S. epidermidis isolated from dental caries and healthy individual. Also, two important cytokines in inflammation were assayed caused due to S. epidermidis of health and dental caries sources. Dental caries strains were more resistant with high MIC 50 and MIC 90 value. These isolates also showed the presence of mecA gene and another virulence gene i. e sea and seb comparatively more than healthy individual isolates. SCCmec types, III and IV was more prevalent in dental caries isolates where an as healthy individual was more non-typable. Additionally, the quantity of IL-1β and IL-8 caused due to dental caries isolates was seen more which indicate dental caries isolates are able to induce. This study showed that S. epidermidis a normal flora of oropharyngeal are more diverse to those strains which cause dental caries. S. epidermidis owns a prodigious genetic plasticity that permits to obtain, lose or regulate genetic elements that provide compensations to improve its colonization in the host. Copyright © 2017 Elsevier Ltd. All rights reserved.

Successful nonsurgical endodontic outcome of a severely affected permanent maxillary canine with dens invaginatus Oehlers type 3.

PubMed

Brooks, John K; Ribera, Michael J

2014-10-01

The morphogenic complexities of dens invaginatus (DI) Oehlers type 3 in maxillary canines offer significant endodontic challenges. A case report is provided of a 14-year-old female patient who presented with an anomalous-looking permanent maxillary canine associated with a sinus tract. Pulp testing revealed a normal response on the distal aspect of the tooth, whereas the mesial segment tested nonresponsive. A radiolucent lesion was seen on the mesiolateral radicular area adjacent to the severely distended pulp chamber. A gutta-percha point inserted into the sinus tract traced to this same region. The diagnosis was normal pulp coincident with DI Oehlers type 3 with pulp necrosis and chronic apical abscess. Despite a concerted effort to limit the root canal therapy to only the necrotic canal, its proximity to the normal canal obviated this possibility, entailing endodontic treatment of the entire root canal system. The necrotic pulp space was subjected to sustained irrigation with 5.25% sodium hypochlorite and then completed with 17% ethylenediaminetetraacetic acid. A bolus of gutta-percha was used to create an apical barrier, and then the remainder of the enlarged pulp space was obturated with injectable thermoplasticized gutta-percha. At a 4.5-year recall, there was no clinical and radiographic evidence of infection. Endodontic success was accomplished with meticulous efforts of disinfection. Thermoplasticized gutta-percha can offer utility for obturation of anatomically complicated pulp spaces. The use of the dental operating microscope is an invaluable aid for discernment of the intricacies of teeth affected with DI type 3 variant and can enhance clinical outcomes. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Assessment of the Tumorigenic Potential of Spontaneously Immortalized and hTERT-Immortalized Cultured Dental Pulp Stem Cells.

PubMed

Wilson, Ryan; Urraca, Nora; Skobowiat, Cezary; Hope, Kevin A; Miravalle, Leticia; Chamberlin, Reed; Donaldson, Martin; Seagroves, Tiffany N; Reiter, Lawrence T

2015-08-01

Dental pulp stem cells (DPSCs) provide an exciting new avenue to study neurogenetic disorders. DPSCs are neural crest-derived cells with the ability to differentiate into numerous tissues including neurons. The therapeutic potential of stem cell-derived lines exposed to culturing ex vivo before reintroduction into patients could be limited if the cultured cells acquired tumorigenic potential. We tested whether DPSCs that spontaneously immortalized in culture acquired features of transformed cells. We analyzed immortalized DPSCs for anchorage-independent growth, genomic instability, and ability to differentiate into neurons. Finally, we tested both spontaneously immortalized and human telomerase reverse transcriptase (hTERT)-immortalized DPSC lines for the ability to form tumors in immunocompromised animals. Although we observed increased colony-forming potential in soft agar for the spontaneously immortalized and hTERT-immortalized DPSC lines relative to low-passage DPSC, no tumors were detected from any of the DPSC lines tested. We noticed some genomic instability in hTERT-immortalized DPSCs but not in the spontaneously immortalized lines tested. We determined that immortalized DPSC lines generated in our laboratory, whether spontaneously or induced, have not acquired the potential to form tumors in mice. These data suggest cultured DPSC lines that can be differentiated into neurons may be safe for future in vivo therapy for neurobiological diseases. ©AlphaMed Press.

Autologous dental pulp stem cells in periodontal regeneration: a case report.

PubMed

Aimetti, Mario; Ferrarotti, Francesco; Cricenti, Luca; Mariani, Giulia Maria; Romano, Federica

2014-01-01

Histologic findings in animal models suggest that the application of dental pulp stem cells (DPSCs) may promote periodontal regeneration in infrabony defects. This case report describes the clinical and radiographic regenerative potential of autologous DPSCs in the treatment of human noncontained intraosseous defects. A chronic periodontitis patient with one vital third molar requiring extraction was surgically treated. The third molar was extracted and used as an autologous DPSCs source to regenerate the infrabony defect on the mandibular right second premolar. At the 1-year examination, the defect was completely filled with bonelike tissue as confirmed through the reentry procedure.

IFN-γ regulates human dental pulp stem cells behavior via NF-κB and MAPK signaling

PubMed Central

He, Xinyao; Jiang, Wenkai; Luo, Zhirong; Qu, Tiejun; Wang, Zhihua; Liu, Ningning; Zhang, Yaqing; Cooper, Paul R.; He, Wenxi

2017-01-01

During caries, dental pulp expresses a range of pro-inflammatory cytokines in response to the infectious challenge. Interferon gamma (IFN-γ) is a dimerized soluble cytokine, which is critical for immune responses. Previous study has demonstrated that IFN-γ at relative high concentration (100 ng/mL) treatment improved the impaired dentinogenic and immunosuppressive regulatory functions of disease-derived dental pulp stem cells (DPSCs). However, little is known about the regulatory effects of IFN-γ at relative low concentration on healthy DPSC behavior (including proliferation, migration, and multiple-potential differentiation). Here we demonstrate that IFN-γ at relatively low concentrations (0.5 ng/mL) promoted the proliferation and migration of DPSCs, but abrogated odonto/osteogenic differentiation. Additionally, we identified that NF-κB and MAPK signaling pathways are both involved in the process of IFN-γ-regulated odonto/osteogenic differentiation of DPSCs. DPSCs treated with IFN-γ and supplemented with pyrrolidine dithiocarbamate (PDTC, an NF-κB inhibitor) or SB203580 (a MAPK inhibitor) showed significantly improved potential for odonto/osteogenic differentiation of DPSCs both in vivo and in vitro. These data provide important insight into the regulatory effects of IFN-γ on the biological behavior of DPSCs and indicate a promising therapeutic strategy for dentin/pulp tissue engineering in future endodontic treatment. PMID:28098169

Effect of Low-Intensity Pulsed Ultrasound on a Rat Model of Dentin-Dental Pulp Injury and Repair.

PubMed

Wang, Fei; Li, Yueheng; Yang, Zhengyan; Lu, Keke; Zuo, Jing; Zhou, Zhi

2017-01-01

This study investigated histopathologic changes in dental pulp after treatment with low-intensity pulsed ultrasound (LIPUS). Fifty rats were randomly divided into an experimental group (n = 25) and a blank control group (n = 25). In the experimental group, a cavity was prepared in the bilateral maxillary first molars. The upper right first molars were stimulated with LIPUS (30 mW/cm 2 , 1.5 MHz) for 20 min/d. The cavities prepared in the left teeth were used as experimental controls (i.e., no LIPUS). Five rats in each group were sacrificed at days 1, 3, 5, 7 and 14. Inflammatory response was visible at different time points after cavity preparation, peaking at day 3, after which it gradually weakened. More reparative dentin was found on the LIPUS treatment side. transforming growth factor-β1 expression increased after treatment, peaking at day 5 and returning to normal at day 14 on both sides, but was stronger with LIPUS treatment. SMAD2 and SMAD3 expressions in the dental pulp gradually increased after cavity preparation, especially in the experimental group. LIPUS promoted the repair of dentin-pulp complex injury, to a certain extent and should be investigated further as a potential therapy. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Human immature dental pulp stem cells (hIDPSCs), their application to cell therapy and bioengineering: an analysis by systematic revision of the last decade of literature.

PubMed

de Souza, Priscilla Vianna; Alves, Fabiana Bucholdz Teixeira; Costa Ayub, Cristina Lucia Sant'Ana; de Miranda Soares, Maria Albertina; Gomes, Jose Rosa

2013-12-01

During recent years, attention has been given to the potential of therapeutic approaches using stem cells obtained from dental pulp tissue. The aim of this study, therefore, was to give an overview of the papers produced during the last 10 years that have described the use of stem cells obtained from human deciduous teeth in cell therapy or bioengineering. The PubMed database was investigated from January 2002 until July 2011 and the papers published during this period were analyzed according to criteria previously established, using the methodology of systematic review. The measurements were done using "stem cell" as the primary keyword, and "human deciduous teeth dental pulp cell" and "human exfoliated deciduous teeth" as the secondary keywords. Four hundred and seventy-five papers were found. The first screening resulted in 276 papers, from which 84 papers were selected. However, only 11 of them attained the aim proposed in our approach. There were few scientific studies related to direct therapeutic application using stem cells of human deciduous teeth and none of them had been applied to humans. However, the results indicated important and promising applications of the pulp stem-cells in cell therapy and bioengineering as demonstrated by studies in animal models of muscular dystrophy, Parkison's disease, and lupus erythematosus. Copyright © 2013 Wiley Periodicals, Inc.

Effects of Adenosine Triphosphate on Proliferation and Odontoblastic Differentiation of Human Dental Pulp Cells.

PubMed

Wang, Wei; Yi, Xiaosong; Ren, Yanfang; Xie, Qiufei

2016-10-01

Adenosine 5'-triphosphate (ATP) is a potent signaling molecule that regulates diverse biological activities in cells. Its effects on human dental pulp cells (HDPCs) remain unknown. This study aimed to examine the effects of ATP on proliferation and differentiation of HDPCs. Reverse transcription polymerase chain reaction was performed to explore the mRNA expression of P2 receptor subtypes. Cell Counting Kit-8 test and flow cytometry analysis were used to examine the effects of ATP on proliferation and cell cycle of HDPCs. The effects of ATP on differentiation of HDPCs were examined by using alizarin red S staining, energy-dispersive x-ray analysis, Western blot analysis, and real-time polymerase chain reaction. The purinoceptors P2X3, P2X4, P2X5, P2X7, and all P2Y receptor subtypes were confirmed to present in HDPCs. ATP enhanced HDPC proliferation at 10 μmol/L concentration. However, it inhibited cell proliferation by arresting the cell cycle in G0G1 phase (P < .05 versus control) and induced odontoblastic differentiation, ERK/MAPK activation, and dentin matrix protein 1 (DMP1) and dentin sialophosphoprotein (DSPP) mRNA transcriptions at 800 μmol/L concentration. Suramin, an ATP receptor antagonist, inhibited ERK/MAPK activation and HDPC odontoblastic differentiation (P < .05 versus control). Extracellular ATP activates P2 receptors and downstream signaling events that induce HDPC odontogenic differentiation. Thus, ATP may promote dental pulp tissue healing and repair through P2 signaling. Results provide new insights into the molecular regulation of pulpal wound healing. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

[Confusion and solution for vital pulp therapy].

PubMed

Dingming, Huang; Qian, Lu; Qian, Liao; Ling, Ye; Xuedong, Zhou

2017-06-01

Dental pulp tissue plays a role in forming dentin, providing nutrition, conducting pain, and generating protective responses to environmental stimuli. Bacterial infection is the main cause of pulp disease, where histopathological changes are the histological basis for determining the choice of treatment and the evaluation of therapeutic effect. Thus, particular attention should be given to eliminate infection, as well as preserve and maintain pulpal health in teeth that show reversible or limited pulpal injuries. Vital pulp therapy, especially its indications and prognostic factors, has been a research hotspot that often causes confusion among clinicians. In this paper, we briefly introduce the confusion and solution for vital pulp therapy in terms of indications, pulp condition assessment, infection elimination, and capping material selection. In addition, we develop a clinical pathway and an operation normalization of vital pulp therapy to better perform the therapy.

Impact of dental pain on daily living of five-year-old Brazilian preschool children: prevalence and associated factors.

PubMed

Moure-Leite, F R; Ramos-Jorge, J; Ramos-Jorge, M L; Paiva, S M; Vale, M P; Pordeus, I A

2011-12-01

To assess the impact of dental pain on the daily living of 5-year-old preschool children using reports from parents/guardians. A cross-sectional study was carried out involving 549 five-year-old children randomly selected from preschools in the city of Belo Horizonte, Brazil. Data were collected using a previously validated parent-reported questionnaire. The children received dental examinations from a single calibrated examiner. The following outcome variables were selected: age, gender, dental caries, filled teeth, missing teeth, caries involving pulp and social class. Simple and multiple logistic regression analyses were performed on the data. According to parents' reports, 11.1% of children were affected by dental pain in the previous 4 months and of these 72.6% had their daily activities hampered by pain. The majority of these children had difficulty in eating, brushing teeth, sleeping, playing and going to school. The impact of dental pain had a statistically significant association with gender (p=0.001), social class (p=0.009), dental caries (p<0.001), missing teeth (p<0.001), filled teeth (p<0.001) and caries involving pulp (p<0.001). The prevalence of difficulties performing tasks of daily living due to dental pain was relatively high among the children studied.

Comparative characterization of stem cells from human exfoliated deciduous teeth, dental pulp, and bone marrow-derived mesenchymal stem cells.

PubMed

Kunimatsu, Ryo; Nakajima, Kengo; Awada, Tetsuya; Tsuka, Yuji; Abe, Takaharu; Ando, Kazuyo; Hiraki, Tomoka; Kimura, Aya; Tanimoto, Kotaro

2018-06-18

Mesenchymal stem cells (MSCs) are used clinically in tissue engineering and regenerative medicine. The proliferation and osteogenic differentiation potential of MSCs vary according to factors such as tissue source and cell population heterogeneity. Dental tissue has received attention as an easily accessible source of high-quality stem cells. In this study, we compared the in vitro characteristics of dental pulp stem cells from deciduous teeth (SHED), human dental pulp stem cells (hDPSCs), and human bone marrow mesenchymal stem cells (hBMSCs). SEHD and hDPSCs were isolated from dental pulp and analyzed in comparison with human bone marrow (hBM)MSCs. Proliferative capacity of cultured cells was analyzed using a bromodeoxyuridine immunoassay and cell counting. Alkaline phosphatase (ALP) levels were monitored to assess osteogenic differentiation. Mineralization was evaluated by alizarin red staining. Levels of bone marker mRNA were examined by real-time PCR analysis. SHED were highly proliferative compared with hDPSCs and hBMSCs. SHED, hDPSCs, and hBMSCs exhibited dark alizarin red staining on day 21 after induction of osteogenic differentiation, and staining of hBMSCs was significantly higher than that of SHED and hDPSCs by spectrophotometry. ALP staining was stronger in hBMSCs compared with SHED and hDPSCs, and ALP activity was significantly higher in hBMSCs compared with SHED or hDPSCs. SHED showed significantly higher expression of the Runx2 and ALP genes compared with hBMSCs, based on real-time PCR analysis. In bFGF, SHED showed significantly higher expression of the basic fibroblast growth factor (bFGF) gene compared with hDPSCs and hBMSCs. SHED exhibited higher proliferative activity and levels of bFGF and BMP-2 gene expression compared with BMMSCs and DPSCs. The ease of harvesting cells and ability to avoid invasive surgical procedures suggest that SHED may be a useful cell source for application in bone regeneration treatments. Copyright © 2018 Elsevier Inc. All rights reserved.

P16/p53 expression and telomerase activity in immortalized human dental pulp cells

PubMed Central

Egbuniwe, Obi; Idowu, Bernadine D; Funes, Juan M; Grant, Andrew D; Renton, Tara

2011-01-01

Introduction Residing within human dental pulp are cells of an ectomesenchymal origin that have the potential to differentiate into odontoblast-like cells. These cells have a limited growth potential owing to the effects of cell senescence. This study examines the effects of immortalizing odontoblast-like cells on cell proliferation and mineralization by comparing transformed dental pulp stem cells (tDPSCs) and non-transformed dental pulp stem cells (nDPSCs). Results With the exogenous expression of hTERT, tDPSCs maintained a continued expression of odontogenic markers for cell proliferation and mineralization (ALP, COL-1, DMP-1, DSPP, OCN and OPN), as did nDPSCs. Oncoprotein expression was seen in both groups except for a noted absence of p16 in the tDPSCs. nDPSCs also showed lower levels of total ALP and DNA activity in comparison to tDPSCs when assayed, as well as low telomerase activity readings. Methods Using a retroviral vector, exogenous human telomerase reverse transcriptase (hTERT) was expressed in tDPSCs. Both cell groups were cultured, and their telomerase activities were determined using a telomerase quantification assay. Also examined, were the expression of genes involved in proliferation and mineralization, such as human alkaline phosphatase (ALP), β-actin, collagen I (col-1), core binding factor (cbfa)-1, dentin matrix protein (DMP-1), dentin sialophosphoprotein (DSPP), GAPDH, hTERT, osteocalcin (OCN), osteopontin (OPN) as well as oncoproteins involved in senescence (p16, p21 and p53) using RT-PCR. DNA and alkaline phosphate activity was also assayed in both cell groups. Conclusion These results indicate maintenance of odontoblast-like differentiation characteristics after retroviral transformation with hTERT and suggest a possible link with a reduced p16 expression. PMID:22067611

Effects of Non-Collagenous Proteins, TGF-β1, and PDGF-BB on Viability and Proliferation of Dental Pulp Stem Cells

PubMed Central

Tabatabaei, Fahimeh Sadat

2016-01-01

ABSTRACT Objectives The dentin matrix servers as a reservoir of growth factors, sequestered during dentinogenesis. The aim of this study was to assess the viability and proliferation of dental pulp stem cells in the presence of dentin matrix-derived non-collagenous proteins and two growth factors; platelet-derived growth factor BB and transforming growth factor beta 1. Material and Methods The dental pulp cells were isolated and cultured. The dentin proteins were extracted and purified. The MTT assay was performed for assessment of cell viability and proliferation in the presence of different concentrations of dentin proteins and growth factors during 24 - 72 h post-treatment. Results The cells treated with 250 ng/mL dentin proteins had the best viability and proliferation ability in comparison with other concentrations (P < 0.05). The MTT assay demonstrated that cells cultured with 5 ng/mL platelet-derived growth factor BB had the highest viability at each time point as compared to other groups (P < 0.05). However, in presence of platelet-derived growth factor BB alone and in combination with transforming growth factor beta 1 and dentin proteins (10 ng/mL), significant higher viability was seen at all time points (P < 0.05). The least viability and proliferation at each growth factor concentration was seen in cells treated with combination of transforming growth factor beta 1 and dentin proteins at 72 h (P < 0.05). Conclusions The results indicated that the triple combination of growth factors and matrix-derived non-collagenous proteins (especially at 10 ng/mL concentration) has mitogenic effect on dental pulp stem cells. PMID:27099698

Laser Doppler pulp vitality measurements: simulation and measurement

NASA Astrophysics Data System (ADS)

Ertl, T.

2017-02-01

Frequently pulp vitality measurement is done in a dental practice by pressing a frozen cotton pellet on the tooth. This method is subjective, as the patient's response is required, sometimes painful and has moderate sensitivity and specificity. Other methods, based on optical or electrical measurement have been published, but didńt find wide spread application in the dental offices. Laser Doppler measurement of the blood flow in the pulp could be an objective method to measure pulp vitality, but the influence of the gingival blood flow on the measurements is a concern. Therefore experiments and simulations were done to learn more about the gingival blood flow in relation to the pulpal blood flow and how to minimize the influence. First patient measurements were done to show the feasibility clinically. Results: Monte Carlo simulations and bench experiments simulating the blood flow in and around a tooth show that both basic configurations, transmission and reflection measurements are possible. Most favorable is a multi-point measurement with different distances from the gingiva. Preliminary sensitivity / specificity are promising and might allow an objective and painless measurement of tooth vitality.

Mineral Trioxide Aggregate and Portland Cement for Direct Pulp Capping in Dog: A Histopathological Evaluation

PubMed Central

Bidar, Maryam; Naghavi, Neda; Mohtasham, Nooshin; Sheik-Nezami, Mahshid; Fallahrastegar, Amir; Afkhami, Farzaneh; Attaran Mashhadi, Negin; Nargesi, Iman

2014-01-01

Background and aims. Mineral trioxide aggregate and calcium hydroxide are considered the gold standard pulp-capping materials. Recently, Portland cement has been introduced with properties similar to those of mineral trioxide aggregate. Histopathological effects of direct pulp capping using mineral trioxide aggregate and Portland cements on dog dental pulp tissue were evaluated in the present study. Materials and methods. This histopatological study was carried out on 64 dog premolars. First, the pulp was exposed with a sterile bur. Then, the exposed pulp was capped with white or gray mineral trioxide aggregates and white or gray Portland cements in each quadrant and sealed with glass-ionomer. The specimens were evaluated under a light microscope after 6 months. Statistical analysis was carried out using Kruskal-Wallis test. Statistical significance was defined at α=5%. Results. There was no acute inflammation in any of the specimens. Chronic inflammation in white and gray mineral trioxide aggregates and white and gray Portland cements was reported to be 45.5%, 27.3%, 57.1% and 34.1%, respectively. Although the differences were not statistically significant, severe inflammation was observed mostly adjacent to white mineral trioxide aggregate. The largest extent of increased vascularization (45%) and the least increase in fibrous tissue were observed adjacent to white mineral trioxide aggregate, with no significant differences. In addition, the least calcified tissue formed adjacent to white mineral trioxide aggregate, although the difference was not significant. Conclusion. The materials used in this study were equally effective as pulp protection materials following direct pulp capping in dog teeth. PMID:25346831

Cytotoxicities and genotoxicities of cements based on calcium silicate and of dental formocresol.

PubMed

Ko, Hyunjung; Jeong, Youngdan; Kim, Miri

2017-03-01

Increasing interest is being paid to the toxicities of dental materials. The purpose of this study was to determine the cytotoxicities and genotoxicities of endodontic compounds to Chinese hamster ovary (CHO-K1) reproductive cells. Cultured CHO-K1 cells were treated with dental formocresol, two types of calcium hydroxide paste, and two types of mineral trioxide aggregate cement for 24h. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay was performed on each culture, and the micronucleus frequency was determined by performing a micronucleus assay. Alkaline comet assay and γ-H2AX immunofluorescence assay were used to detect DNA damage. Out of the five materials tested, only dental formocresol significantly increased DNA damage. The mineral trioxide aggregate cements based on calcium silicate were not found to be potentially genotoxic. The data suggest that dental formocresol should not be recommended for use in vital pulp therapy on young teeth. Copyright © 2017 Elsevier B.V. All rights reserved.

Differential cholinoceptor modulation of nitric oxide isoforms in experimentally-induced inflammation of dental pulp tissue.

PubMed

De Couto Pita, A; Passafaro, D; Ganzinelli, S; Borda, E; Sterin-Borda, L

2009-06-01

The aim of the study was to investigate the role of muscarinic acetylcholine receptor (mAChR) activity in the regulation of endothelial (e), neuronal (n) and inducible (i) nitric oxide synthase (NOS) activity and expression in experimentally induced inflammation of rat dental pulp tissue. Inflammation was induced by application of bacterial lipopolysaccharide (LPS) to the pulp. Extirpated pulp-tissue samples were incubated in saline solution until the various experiments were performed. Saline-treated pulp and healthy pulp tissues were used as controls. NOS activity was measured by the production of [U-(14)C]-citrulline from [U-(14)C]-arginine. Nitrite/nitrate assay was evaluated by the conversion of nitrate to nitrite in the presence of nicotinamide adenine dinucleotide phosphate. i-nos, e-nos and n-nos mRNA levels were measured using reverse-transcriptase polymerase chain reaction by co-amplification of target cDNA with a single set of primers. Application of LPS to the pulp increased NOS activity and nitrate production (P < 0.001), generated by iNOS over-activity and expression. Pilocarpine acting on mAChRs triggered a biphasic action on NOS activity and NO accumulation. At low concentrations, pilocarpine induced a negative effect associated with a decrease in i-nos mRNA level, whilst at high concentration, it produced a positive effect associated with increased e-nos and n-nos mRNA levels. In control pulp tissue, only the positive effect of pilocarpine was observed. Irreversible pulpitis changes mAChR conformation increasing its efficiency of coupling to transducing molecules that in turn induce activate iNOS. The capacity of pilocarpine to prevent NO accumulation and iNOS activity, by acting on mAChR mutation induced by pulpitis, might be useful therapeutically as a local treatment.

Fluid mechanics in dentinal microtubules provides mechanistic insights into the difference between hot and cold dental pain.

PubMed

Lin, Min; Luo, Zheng Yuan; Bai, Bo Feng; Xu, Feng; Lu, Tian Jian

2011-03-23

Dental thermal pain is a significant health problem in daily life and dentistry. There is a long-standing question regarding the phenomenon that cold stimulation evokes sharper and more shooting pain sensations than hot stimulation. This phenomenon, however, outlives the well-known hydrodynamic theory used to explain dental thermal pain mechanism. Here, we present a mathematical model based on the hypothesis that hot or cold stimulation-induced different directions of dentinal fluid flow and the corresponding odontoblast movements in dentinal microtubules contribute to different dental pain responses. We coupled a computational fluid dynamics model, describing the fluid mechanics in dentinal microtubules, with a modified Hodgkin-Huxley model, describing the discharge behavior of intradental neuron. The simulated results agreed well with existing experimental measurements. We thence demonstrated theoretically that intradental mechano-sensitive nociceptors are not "equally sensitive" to inward (into the pulp) and outward (away from the pulp) fluid flows, providing mechanistic insights into the difference between hot and cold dental pain. The model developed here could enable better diagnosis in endodontics which requires an understanding of pulpal histology, neurology and physiology, as well as their dynamic response to the thermal stimulation used in dental practices.

Fluid Mechanics in Dentinal Microtubules Provides Mechanistic Insights into the Difference between Hot and Cold Dental Pain

PubMed Central

Lin, Min; Luo, Zheng Yuan; Bai, Bo Feng; Xu, Feng; Lu, Tian Jian

2011-01-01

Dental thermal pain is a significant health problem in daily life and dentistry. There is a long-standing question regarding the phenomenon that cold stimulation evokes sharper and more shooting pain sensations than hot stimulation. This phenomenon, however, outlives the well-known hydrodynamic theory used to explain dental thermal pain mechanism. Here, we present a mathematical model based on the hypothesis that hot or cold stimulation-induced different directions of dentinal fluid flow and the corresponding odontoblast movements in dentinal microtubules contribute to different dental pain responses. We coupled a computational fluid dynamics model, describing the fluid mechanics in dentinal microtubules, with a modified Hodgkin-Huxley model, describing the discharge behavior of intradental neuron. The simulated results agreed well with existing experimental measurements. We thence demonstrated theoretically that intradental mechano-sensitive nociceptors are not “equally sensitive” to inward (into the pulp) and outward (away from the pulp) fluid flows, providing mechanistic insights into the difference between hot and cold dental pain. The model developed here could enable better diagnosis in endodontics which requires an understanding of pulpal histology, neurology and physiology, as well as their dynamic response to the thermal stimulation used in dental practices. PMID:21448459

[Heat-induced symptomatology in human teeth. An in-vitro study].

PubMed

Baldissara, P; Bortolini, S; Papale, G; Scotti, R

1998-09-01

Various dental procedures can generate thermal increase in the dental pulp, in particular if they are incorrectly conducted. In literature the pulp cells are considered very heat sensitive. In this study the symptomatological response of patients during and after thermal administration to the dental crown has been recorded. The analysis of the symptomatology was used as an indication for the definition of the threshold of thermal damage. Twelve healthy teeth of four patients programmed for extraction were subdivided into six couples of homologous teeth. One tooth out of each couple was used for the immediate in vivo recording of the symptoms; the other, once extracted, was used to determine the thermal increase applied through the insertion of a thermocouple sensor. In each couple of teeth the thermal stimulus was equal. The average thermal increase was 11.2 degrees C. Pain starts at temperatures ranging from 39.5 to 50.4 degrees C with an average of 44.6 degrees C. This agrees with classical physiological data which reports the threshold of pain at 45 degrees C. The threshold of pain registered suggests that at temperatures below 44.6 degrees C damage to the dental pulp is improbable, at least in healthy teeth. The limit of 45 degrees C appears, therefore, to be a probable safe threshold, contrary to what is reported in literature.

Sodium hypochlorite with reduced surface tension does not improve in situ pulp tissue dissolution.

PubMed

De-Deus, Gustavo; de Berredo Pinho, Marco André; Reis, Claudia; Fidel, Sandra; Souza, Erick; Zehnder, Matthias

2013-08-01

Sodium hypochlorite (NaOCl) solutions with added wetting agents are advertised to dissolve necrotic tissue in root canals faster than their counterparts without a lowered surface tension. This was tested in the current study, and the null hypothesis formulated was that there was no difference between a commercially available NaOCl solution with a lowered surface tension (Chlor-XTRA; Vista Dental Products, Racine, WI) and a counterpart containing the same amount of available chlorine without added wetting agents regarding the soft tissue that remains in oval-shaped canals after mechanical preparation and irrigation. Formerly vital extracted teeth (N = 44, 22 pairs) with similar anatomy were radiographically paired and chemomechanically prepared. In 1 tooth from each pair, a 5.25% NaOCl solution with reduced surface tension was used; in the other, a pure, technical-grade NaOCl solution of 5.25% was used. The percentage of remaining pulp tissue (PRPT) was histologically assessed in root cross-sections. The non-Gaussian raw data were subjected to Kruskal-Wallis and Mann-Whitney U tests to verify the respective effect of the cross-section level and solution on the PRPT. The relationship between the cross-section level and the PRPT was estimated by the Spearman correlation test. The alpha-type error was set at 5%. The cross-section level significantly influenced the PRPT (P < .05), whereas the PRPT was not influenced by the solution used (P > .05). A significant inverse correlation was found between the cross-section level and the PRPT (P < .05, r = -0.330). The lower the distance to the apex, the higher the PRPT regardless of the solution used. Contrary to the advertised statement, the dental solution with a reduced surface tension did not dissolve vital pulp tissue in oval root canals any better than a conventional NaOCl solution of similar strength. Closer to the apex, pulp tissue dissolution is less efficient irrespective of the solution. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

The dental cavities of equine cheek teeth: three-dimensional reconstructions based on high resolution micro-computed tomography

PubMed Central

2012-01-01

Background Recent studies reported on the very complex morphology of the pulp system in equine cheek teeth. The continuous production of secondary dentine leads to distinct age-related changes of the endodontic cavity. Detailed anatomical knowledge of the dental cavities in all ages is required to explain the aetiopathology of typical equine endodontic diseases. Furthermore, data on mandibular and maxillary pulp systems is in high demand to provide a basis for the development of endodontic therapies. However, until now examination of the pulp cavity has been based on either sectioned teeth or clinical computed tomography. More precise results were expected by using micro-computed tomography with a resolution of about 0.1 mm and three-dimensional reconstructions based on previous greyscale analyses and histological verification. The aim of the present study was to describe the physiological configurations of the pulp system within a wide spectrum of tooth ages. Results Maxillary teeth: All morphological constituents of the endodontic cavity were present in teeth between 4 and 16 years: Triadan 06s displayed six pulp horns and five root canals, Triadan 07-10s five pulp horns and four root canals and Triadan 11s seven pulp horns and four to six root canals. A common pulp chamber was most frequent in teeth ≤5 years, but was found even in a tooth of 9 years. A large variety of pulp configurations was observed within 2.5 and 16 years post eruption, but most commonly a separation into mesial and distal pulp compartments was seen. Maxillary cheek teeth showed up to four separate pulp compartments but the frequency of two, three and four pulp compartments was not related to tooth age (P > 0.05). In Triadan 06s, pulp horn 6 was always connected to pulp horns 1 and 3 and root canal I. In Triadan 11s, pulp horns 7 and 8 were present in variable constitutions. Mandibular teeth: A common pulp chamber was present in teeth up to 15 years, but most commonly seen in teeth ≤5 years. A segmented pulp system was found in 72% of the investigated teeth. Segmentation into separate mesial and distal pulp compartments was most commonly present. Pulp horn 4 coalesced either with the mesial pulp horns 1 and 3 or with the distal pulp horns 2 and 5. Conclusions Details of the pulpar anatomy of equine cheek teeth are provided, supporting the continuous advancement in endodontic therapy. Numerous individual configurations of the pulp system were obtained in maxillary cheek teeth, but much less variability was seen in mandibular cheek teeth. PMID:23006500

Evaluation of accuracy, reliability, and repeatability of five dental pulp tests.

PubMed

Chen, Eugene; Abbott, Paul V

2011-12-01

The aim of this study was to compare the clinical accuracy, reliability, and repeatability of laser Doppler flowmetry (LDF), an electric pulp test (EPT), and various thermal pulp sensibility tests. Pulp tests were done on 121 teeth in 20 subjects by using LDF, EPT, and thermal pulp testing (CO(2), Endo Frost [EF], Ice) during 2 or 3 test sessions with at least 1-week intervals. The order of testing was reversed on the second visit. A laser Doppler flowmeter was used to measure mean pulp blood flow (Flux) calibrated against a brownian motion medium and zeroed against a static reflector. The laser source was 780 nm, with 0.5-mm fiber separation in the probe, 3.1 kHz as the primary bandwidth for filter set to 0.1-second time output constant. Customized polyvinylsiloxane splints were fabricated for each participant, and a minimum of 90-second recording time was used for each tooth. Raw data were analyzed by using repeated measure analysis of variance, pairwise comparisons, and interclass correlations (ICC). The accuracy of EPT, CO(2), and LDF tests was 97.7%, 97.0%, and 96.3%, respectively, without significant differences (P > .3). Accuracy of EF and Ice was 90.7% and 84.8%, respectively. EPT (P = .015) and CO(2) (P = .022) were significantly more accurate than EF. LDF was more accurate than EF, but this was not statistically significant (P = .063). Ice was significantly less accurate than EPT (P = .004), CO(2) (P = .005), LDF (P = .006), and EF (P = .019). With the exception of Ice (effect of visit: F(2,38) = 5.67, mean squared error = 0.01, P = .007, η(2)(p) = 0.23), all tests were reliable. Ice (ICC = 0.677) and LDF (ICC = 0.654) were the most repeatable of the tests, whereas EPT (ICC = 0.434) and CO(2) (ICC = 0.432) were less repeatable. CO(2), EPT, and LDF were reliable and the most accurate tests, but CO(2) and EPT were less repeatable yet less time-consuming than LDF. EF was reliable but not as accurate as EPT and CO(2) and less repeatable than Ice and LDF. Ice was the most repeatable but the least accurate and least reliable test. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Stem cell-based biological tooth repair and regeneration

PubMed Central

Volponi, Ana Angelova; Pang, Yvonne; Sharpe, Paul T.

2010-01-01

Teeth exhibit limited repair in response to damage, and dental pulp stem cells probably provide a source of cells to replace those damaged and to facilitate repair. Stem cells in other parts of the tooth, such as the periodontal ligament and growing roots, play more dynamic roles in tooth function and development. Dental stem cells can be obtained with ease, making them an attractive source of autologous stem cells for use in restoring vital pulp tissue removed because of infection, in regeneration of periodontal ligament lost in periodontal disease, and for generation of complete or partial tooth structures to form biological implants. As dental stem cells share properties with mesenchymal stem cells, there is also considerable interest in their wider potential to treat disorders involving mesenchymal (or indeed non-mesenchymal) cell derivatives, such as in Parkinson's disease. PMID:21035344

Biphasic effects of FGF2 on odontoblast differentiation involve changes in the BMP and Wnt signaling pathways.

PubMed

Sagomonyants, Karen; Mina, Mina

2014-08-01

Odontoblast differentiation during physiological and reparative dentinogenesis is dependent upon multiple signaling molecules, including fibroblast growth factors (FGFs), bone morphogenetic proteins (BMPs) and Wingless/Integrated (Wnt) ligands. Recent studies in our laboratory showed that continuous exposure of primary dental pulp cultures to FGF2 exerted biphasic effects on the expression of markers of dentinogenesis. In the present study, we examined the possible involvement of the BMP and Wnt signaling pathways in mediating the effects of FGF2 on dental pulp cells. Our results showed that stimulatory effects of FGF2 on dentinogenesis during the proliferation phase of growth were associated with increased expression of the components of the BMP (Bmp2, Dlx5, Msx2, Osx) and Wnt (Wnt10a, Wisp2) pathways, and decreased expression of an inhibitor of the Wnt signaling, Nkd2. Further addition of FGF2 during the differentiation/mineralization phase of growth resulted in decreased expression of components of the BMP signaling (Bmp2, Runx2, Osx) and increased expression of inhibitors of the Wnt signaling (Nkd2, Dkk3). This suggests that both BMP and Wnt pathways may be involved in mediating the effects of FGF2 on dental pulp cells.

Evaluation of an experimental rat model for comparative studies of bleaching agents.

PubMed

Cintra, Luciano Tavares Angelo; Benetti, Francine; Ferreira, Luciana Louzada; Rahal, Vanessa; Ervolino, Edilson; Jacinto, Rogério de Castilho; Gomes Filho, João Eduardo; Briso, André Luiz Fraga

2016-04-01

Dental materials in general are tested in different animal models prior to the clinical use in humans, except for bleaching agents. Objectives To evaluate an experimental rat model for comparative studies of bleaching agents, by investigating the influence of different concentrations and application times of H2O2 gel in the pulp tissue during in-office bleaching of rats' vital teeth. Material and Methods The right and left maxillary molars of 50 Wistar rats were bleached with 20% and 35% H2O2 gels, respectively, for 5, 10, 15, 30, or 45 min (n=10 rats/group). Ten animals were untreated (control). The rats were killed after 2 or 30 days, and the maxillae were examined by light microscopy. Inflammation was evaluated through histomorphometric analysis with inflammatory cell count in the coronal and radicular thirds of the pulp. Fibroblasts were also counted. Scores were attributed to odontoblastic layer and vascular changes. Tertiary dentin area and pulp chamber central area were measured histomorphometrically. Data were compared by analysis of variance and Kruskal-Wallis test (p<0.05). Results After 2 days, the amount of inflammatory cells increased in the coronal pulp occlusal third up to the 15-min application groups of each bleaching gel. In the groups exposed to each concentration for 30 and 45 min, the number of inflammatory cells decreased along with the appearance of necrotic areas. After 30 days, reduction on the pulp chamber central area and enlargement of the tertiary dentin area were observed, without the detection of inflammation areas. Conclusion The rat model of extracoronal bleaching showed to be adequate for studies of bleaching protocols, as it was possible to observe alterations in the pulp tissues and tooth structure caused by different concentrations and application periods of bleaching agents.

Evaluation of an experimental rat model for comparative studies of bleaching agents

PubMed Central

CINTRA, Luciano Tavares Angelo; BENETTI, Francine; FERREIRA, Luciana Louzada; RAHAL, Vanessa; ERVOLINO, Edilson; JACINTO, Rogério de Castilho; GOMES, João Eduardo; BRISO, André Luiz Fraga

2016-01-01

ABSTRACT Dental materials in general are tested in different animal models prior to the clinical use in humans, except for bleaching agents. Objectives To evaluate an experimental rat model for comparative studies of bleaching agents, by investigating the influence of different concentrations and application times of H2O2 gel in the pulp tissue during in-office bleaching of rats’ vital teeth. Material and Methods The right and left maxillary molars of 50 Wistar rats were bleached with 20% and 35% H2O2 gels, respectively, for 5, 10, 15, 30, or 45 min (n=10 rats/group). Ten animals were untreated (control). The rats were killed after 2 or 30 days, and the maxillae were examined by light microscopy. Inflammation was evaluated through histomorphometric analysis with inflammatory cell count in the coronal and radicular thirds of the pulp. Fibroblasts were also counted. Scores were attributed to odontoblastic layer and vascular changes. Tertiary dentin area and pulp chamber central area were measured histomorphometrically. Data were compared by analysis of variance and Kruskal-Wallis test (p<0.05). Results After 2 days, the amount of inflammatory cells increased in the coronal pulp occlusal third up to the 15-min application groups of each bleaching gel. In the groups exposed to each concentration for 30 and 45 min, the number of inflammatory cells decreased along with the appearance of necrotic areas. After 30 days, reduction on the pulp chamber central area and enlargement of the tertiary dentin area were observed, without the detection of inflammation areas. Conclusion The rat model of extracoronal bleaching showed to be adequate for studies of bleaching protocols, as it was possible to observe alterations in the pulp tissues and tooth structure caused by different concentrations and application periods of bleaching agents. PMID:27119766

Heat effect of pulsed Er:YAG laser radiation

NASA Astrophysics Data System (ADS)

Hibst, Raimund; Keller, Ulrich

1990-06-01

Pulsed Er:YAG laser radiation has been found to be effective for dental enamel and dentin removal. Damage to the surrounding hard tissue is little, but before testing the Er:YAG laser clinically for the preparation of cavities, possible effects on the soft tissue of the pulp must be known. In order to estimate pulp damage , temperature rise in dentin caused by the laser radiation was measured by a thermocouple. Additionally, temperature distributions were observed by means of a thermal imaging system. The heat effect of a single Er:YAG laser pulse is little and limited to the vicinity of the impact side. Because heat energy is added with each additional pulse , the temperature distribution depends not only on the radiant energy, but also on the number of pulses and the repetition rate. Both irradiation conditions can be found , making irreversible pulp damage either likely or unlikely. The experimental observations can be explained qualitatively by a simple model of the ablation process.

Curricular Guidelines for Endodontics.

ERIC Educational Resources Information Center

Journal of Dental Education, 1981

1981-01-01

Guidelines developed by the Section on Endodontics of the American Association of Dental Schools for use by educational institutions as curriculum development aids are provided. Endodontics is that branch of dentistry dealing with diagnosis and treatment of oral conditions that arise as a result of pathoses of dental pulp. (MLW)

Penetration parameters of low-intensity laser light in dental configurations for therapeutic applications

NASA Astrophysics Data System (ADS)

Uzunov, Tzonko; Gizbreht, Alexander I.; Nenchev, Marin N.

1996-12-01

The results of the measurement of the penetration of the laser light inside dental configurations are reported. The illumination of the pulp chamber is carried out. The results can be employed in clinical practice for dosage in treatment of periodontal diseases.

Temporal dynamics of anxiety phenotypes in a dental pulp injury model.

PubMed

Shang, Lin; Xu, Tian-Le; Li, Fei; Su, Jiansheng; Li, Wei-Guang

2015-06-30

Accumulating clinical and preclinical evidence indicates that chronic pain is often comorbid with persistent low mood and anxiety. However, the mechanisms underlying pain-induced anxiety, such as its causality, temporal progression, and relevant neural networks are poorly understood, impeding the development of efficacious therapeutic approaches. Here, we have identified the sequential emergence of anxiety phenotypes in mice subjected to dental pulp injury (DPI), a prototypical model of orofacial pain that correlates with human toothache. Compared with sham controls, mice subjected to DPI by mechanically exposing the pulp to the oral environment exhibited significant signs of anxiogenic effects, specifically, altered behaviors on the elevated plus maze (EPM), novelty-suppressed feeding (NSF) tests at 1 but not 3 days after the surgery. Notably, at 7 and 14 days, the DPI mice again avoided the open arm, center area, and novelty environment in the EPM, open field, and NSF tests, respectively. In particular, DPI-induced social phobia and increased repetitive grooming did not occur until 14 days after surgery, suggesting that DPI-induced social anxiety requires a long time. Moreover, oral administration of an anti-inflammatory drug, ibuprofen, or an analgesic agent, ProTx-II, which is a selective inhibitor of NaV1.7 sodium channels, both significantly alleviated DPI-induced avoidance in mice. Finally, to investigate the underlying central mechanisms, we pharmacologically blocked a popular form of synaptic plasticity with a GluA2-derived peptide, long-term depression, as that treatment significantly prevented the development of anxiety phenotype upon DPI. Together, these results suggest a temporally progressive causal relationship between orofacial pain and anxiety, calling for more in-depth mechanistic studies on concomitant pain and anxiety disorders.

Dental pulp stem cells as a multifaceted tool for bioengineering and the regeneration of craniomaxillofacial tissues

PubMed Central

Aurrekoetxea, Maitane; Garcia-Gallastegui, Patricia; Irastorza, Igor; Luzuriaga, Jon; Uribe-Etxebarria, Verónica; Unda, Fernando; Ibarretxe, Gaskon

2015-01-01

Dental pulp stem cells, or DPSC, are neural crest-derived cells with an outstanding capacity to differentiate along multiple cell lineages of interest for cell therapy. In particular, highly efficient osteo/dentinogenic differentiation of DPSC can be achieved using simple in vitro protocols, making these cells a very attractive and promising tool for the future treatment of dental and periodontal diseases. Among craniomaxillofacial organs, the tooth and salivary gland are two such cases in which complete regeneration by tissue engineering using DPSC appears to be possible, as research over the last decade has made substantial progress in experimental models of partial or total regeneration of both organs, by cell recombination technology. Moreover, DPSC seem to be a particularly good choice for the regeneration of nerve tissues, including injured or transected cranial nerves. In this context, the oral cavity appears to be an excellent testing ground for new regenerative therapies using DPSC. However, many issues and challenges need yet to be addressed before these cells can be employed in clinical therapy. In this review, we point out some important aspects on the biology of DPSC with regard to their use for the reconstruction of different craniomaxillofacial tissues and organs, with special emphasis on cranial bones, nerves, teeth, and salivary glands. We suggest new ideas and strategies to fully exploit the capacities of DPSC for bioengineering of the aforementioned tissues. PMID:26528190

Pulp regeneration in a full-length human tooth root using a hierarchical nanofibrous microsphere system.

PubMed

Li, Xiangwei; Ma, Chi; Xie, Xiaohua; Sun, Hongchen; Liu, Xiaohua

2016-04-15

While pulp regeneration using tissue engineering strategy has been explored for over a decade, successful regeneration of pulp tissues in a full-length human root with a one-end seal that truly simulates clinical endodontic treatment has not been achieved. To address this challenge, we designed and synthesized a unique hierarchical growth factor-loaded nanofibrous microsphere scaffolding system. In this system, vascular endothelial growth factor (VEGF) binds with heparin and is encapsulated in heparin-conjugated gelatin nanospheres, which are further immobilized in the nanofibers of an injectable poly(l-lactic acid) (PLLA) microsphere. This hierarchical microsphere system not only protects the VEGF from denaturation and degradation, but also provides excellent control of its sustained release. In addition, the nanofibrous PLLA microsphere integrates the extracellular matrix-mimicking architecture with a highly porous injectable form, efficiently accommodating dental pulp stem cells (DPSCs) and supporting their proliferation and pulp tissue formation. Our in vivo study showed the successful regeneration of pulp-like tissues that fulfilled the entire apical and middle thirds and reached the coronal third of the full-length root canal. In addition, a large number of blood vessels were regenerated throughout the canal. For the first time, our work demonstrates the success of pulp tissue regeneration in a full-length root canal, making it a significant step toward regenerative endodontics. The regeneration of pulp tissues in a full-length tooth root canal has been one of the greatest challenges in the field of regenerative endodontics, and one of the biggest barriers for its clinical application. In this study, we developed a unique approach to tackle this challenge, and for the first time, we successfully regenerated living pulp tissues in a full-length root canal, making it a significant step toward regenerative endodontics. This study will make positive scientific impact and interest the broad and multidisciplinary readership in the dental biomaterials and craniofacial tissue engineering community. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Cytokine signalling in rat pulp interstitial fluid and transcapillary fluid exchange during lipopolysaccharide-induced acute inflammation

PubMed Central

Bletsa, Athanasia; Berggreen, Ellen; Fristad, Inge; Tenstad, Olav; Wiig, Helge

2006-01-01

The dental pulp consists of loose connective tissue encased in rigid dentinal walls. Because of its topography the tissue has low interstitial compliance and limited capacity to expand during fluid volume changes. Due to limitations regarding access to interstitial fluid, basic knowledge on transcapillary fluid transport parameters is lacking for this organ. The scope of this project was dual: first we aimed at establishing a method for isolation of pulp interstitial fluid (IF), and second we applied the method in rats subjected to lipopolysaccharide (LPS)-induced endotoxaemia. The aim was to measure colloid osmotic pressure (COP) and pro-inflammatory cytokines in the pulp IF during acute inflammation. Fluid volumes and pulpal blood flow (PBF) were measured to obtain more information about microcirculatory changes that take place in this pulpitis model. By centrifugation of incisor pulp at 239 g we were able to extract fluid representative for IF. Pulp IF had a relative high control COP (∼83% of plasma COP) and was similar to plasma COP 3 h after LPS challenge. The pulp exhibited a high content of IF (0.60 ± 0.03 ml (g wet weight)−1) and a vascular volume of 0.03 ± 0.01 ml (g w.w.)−1 No differences were observed in the distribution of fluid volumes after 1.5 and 3 h LPS exposure. PBF and systemic blood pressure dropped significantly after LPS administration. PBF remained low whereas systemic blood pressure was re-established during the 3-h period, implying organ dysfunction. There was a differential pattern of cytokine expression in pulp IF and serum with cytokines such as IL-1α, IL-1β and TNF-α locally produced, whereas others such as IFN-γ and IL-6 were produced systemically and probably spilled over to the pulp IF after LPS exposure. Our findings show that pulp IF can be isolated by centrifugation and that this method is useful when studying fluid balance and extracellular signalling mechanisms in the dental pulp in normal and pathological conditions. PMID:16527857

Pulp Cell Tracking by Radionuclide Imaging for Dental Tissue Engineering

PubMed Central

Souron, Jean-Baptiste; Petiet, Anne; Decup, Franck; Tran, Xuan Vinh; Lesieur, Julie; Poliard, Anne; Le Guludec, Dominique; Letourneur, Didier; Chaussain, Catherine; Rouzet, Francois

2014-01-01

Pulp engineering with dental mesenchymal stem cells is a promising therapy for injured teeth. An important point is to determine the fate of implanted cells in the pulp over time and particularly during the early phase following implantation. Indeed, the potential engraftment of the implanted cells in other organs has to be assessed, in particular, to evaluate the risk of inducing ectopic mineralization. In this study, our aim was to follow by nuclear imaging the radiolabeled pulp cells after implantation in the rat emptied pulp chamber. For that purpose, indium-111-oxine (111In-oxine)-labeled rat pulp cells were added to polymerizing type I collagen hydrogel to obtain a pulp equivalent. This scaffold was implanted in the emptied pulp chamber space in the upper first rat molar. Labeled cells were then tracked during 3 weeks by helical single-photon emission computed tomography (SPECT)/computed tomography performed on a dual modality dedicated small animal camera. Negative controls were performed using lysed radiolabeled cells obtained in a hypotonic solution. In vitro data indicated that 111In-oxine labeling did not affect cell viability and proliferation. In vivo experiments allowed a noninvasive longitudinal follow-up of implanted living cells for at least 3 weeks and indicated that SPECT signal intensity was related to implanted cell integrity. Notably, there was no detectable systemic release of implanted cells from the tooth. In addition, histological analysis of the samples showed mitotically active fibroblastic cells as well as neoangiogenesis and nervous fibers in pulp equivalents seeded with entire cells, whereas pulp equivalents prepared from lysed cells were devoid of cell colonization. In conclusion, our study demonstrates that efficient labeling of pulp cells can be achieved and, for the first time, that these cells can be followed up after implantation in the tooth by nuclear imaging. Furthermore, it appears that grafted cells retained the label and are viable to follow the repair process. This technique is expected to be of major interest for monitoring implanted cells in innovative therapies for injured teeth. PMID:23789732

Effects of TGF-β1 on plasminogen activation in human dental pulp cells: Role of ALK5/Smad2, TAK1 and MEK/ERK signalling.

PubMed

Chang, Mei-Chi; Chang, Hsiao-Hua; Lin, Po-Shuan; Huang, Yu-An; Chan, Chiu-Po; Tsai, Yi-Ling; Lee, Shen-Yang; Jeng, Po-Yuan; Kuo, Han-Yueh; Yeung, Sin-Yuet; Jeng, Jiiang-Huei

2018-04-01

Transforming growth factor-β1 (TGF-β1) plays an important role in the pulpal repair and dentinogenesis. Plasminogen activation (PA) system regulates extracellular matrix turnover. In this study, we investigated the effects of TGF-β1 on PA system of dental pulp cells and its signalling pathways. Dental pulp cells were treated with different concentrations of TGF-β1. MTT assay, reverse transcription-polymerase chain reaction, Western blotting and enzyme-linked immunosorbant assay (ELISA) were used to detect the effect of TGF-β1 on cell viability, mRNA and protein expression of urokinase-type plasminogen activator (uPA), uPA receptor (uPAR), plasminogen activator inhibitor-1 (PAI-1) as well as their secretion. The phosphorylation of Smad2 and TAK1 was analysed by Pathscan ELISA or Western blotting. Cells were pretreated with SB431542 (ALK5/Smad2/3 inhibitor), 5z-7-oxozeaenol (TAK1 inhibitor) and U0126 (MEK/ERK inhibitor) for examining the related signalling. TGF-β1 slightly inhibited cell growth that was reversed by SB431542. TGF-β1 upregulated both RNA and protein expression of PAI-1 and uPAR, whereas it downregulated uPA expression. Accordingly, TGF-β1 stimulated PAI-1 and soluble uPAR (suPAR) secretion of pulp cells, whereas uPA secretion was inhibited. TGF-β1 induced the phosphorylation of Smad2 and TAK1. In addition, SB431542, 5z-7-oxozeaenol and U0126 attenuated the TGF-β1-induced secretion of PAI-1 and suPAR. These results indicate that TGF-β1 is possibly involved in the repair/regeneration and inflammatory processes of dental pulp via regulation of PAI-1, uPA and uPAR. These effects of TGF-β1 are related to activation of ALK5/Smad2, TAK1 and MEK/ERK signalling pathways. Clarifying the signal transduction for the effects of TGF-β1 is helpful for pulpo-dentin regeneration and tissue engineering. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

In vitro assessment of pulp chamber temperature of different teeth submitted to dental bleaching associated with LED/laser and halogen lamp appliances.

PubMed

Torres, Carlos Rocha Gomes; Caneppele, Taciana Marco Ferraz; Arcas, Felipe Carlos Dias; Borges, Alessandra Buhler

2008-01-01

This study sought to assess the pulp chamber temperature in different groups of human teeth that had been bleached using hydrogen peroxide gel activated with halogen lamps or hybrid LED/laser appliances. Four groups of ten teeth (maxillary central incisors, mandibular incisors, mandibular canines, and maxillary canines) were used. A digital thermometer with a K-type thermocouple was placed inside pulp chambers that had been filled with thermal paste. A 35% hydrogen peroxide-based red bleaching gel was applied to all teeth and photocured for a total of three minutes and 20 seconds (five activations of 40 seconds each), using light from an LED/laser device and a halogen lamp. The temperatures were gauged every 40 seconds and the data were analyzed by three-way ANOVA, followed by Tukey's test. Regardless of the light source, statistically significant differences were observed between the groups of teeth. The mean temperature values (+/- SD) were highest for maxillary central incisors and lowest for mandibular canines. The halogen lamp appliance produced more pulp chamber heating than the LED/laser appliance. The increase in irradiation time led to a significant increase in temperature.

Viral MicroRNAs Identified in Human Dental Pulp.

PubMed

Zhong, Sheng; Naqvi, Afsar; Bair, Eric; Nares, Salvador; Khan, Asma A

2017-01-01

MicroRNAs (miRs) are a family of noncoding RNAs that regulate gene expression. They are ubiquitous among multicellular eukaryotes and are also encoded by some viruses. Upon infection, viral miRs (vmiRs) can potentially target gene expression in the host and alter the immune response. Although prior studies have reported viral infections in human pulp, the role of vmiRs in pulpal disease is yet to be explored. The purpose of this study was to examine the expression of vmiRs in normal and diseased pulps and to identify potential target genes. Total RNA was extracted and quantified from normal and inflamed human pulps (N = 28). Expression profiles of vmiRs were then interrogated using miRNA microarrays (V3) and the miRNA Complete Labeling and Hyb Kit (Agilent Technologies, Santa Clara, CA). To identify vmiRs that were differentially expressed, we applied a permutation test. Of the 12 vmiRs detected in the pulp, 4 vmiRs (including those from herpesvirus and human cytomegalovirus) were differentially expressed in inflamed pulp compared with normal pulp (P < .05). Using bioinformatics, we identified potential target genes for the differentially expressed vmiRs. They included key mediators involved in the detection of microbial ligands, chemotaxis, proteolysis, cytokines, and signal transduction molecules. These data suggest that miRs may play a role in interspecies regulation of pulpal health and disease. Further research is needed to elucidate the mechanisms by which vmiRs can potentially modulate the host response in pulpal disease. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Application of Stem Cell Technology in Dental Regenerative Medicine.

PubMed

Feng, Ruoxue; Lengner, Chistopher

2013-07-01

In this review, we summarize the current literature regarding the isolation and characterization of dental tissue-derived stem cells and address the potential of these cell types for use in regenerative cell transplantation therapy. Looking forward, platforms for the delivery of stem cells via scaffolds and the use of growth factors and cytokines for enhancing dental stem cell self-renewal and differentiation are discussed. We aim to understand the developmental origins of dental tissues in an effort to elucidate the molecular pathways governing the genesis of somatic dental stem cells. The advantages and disadvantages of several dental stem cells are discussed, including the developmental stage and specific locations from which these cells can be purified. In particular, stem cells from human exfoliated deciduous teeth may act as a very practical and easily accessibly reservoir for autologous stem cells and hold the most value in stem cell therapy. Dental pulp stem cells and periodontal ligament stem cells should also be considered for their triple lineage differentiation ability and relative ease of isolation. Further, we address the potentials and limitations of induced pluripotent stem cells as a cell source in dental regenerative. From an economical and a practical standpoint, dental stem cell therapy would be most easily applied in the prevention of periodontal ligament detachment and bone atrophy, as well as in the regeneration of dentin-pulp complex. In contrast, cell-based tooth replacement due to decay or other oral pathology seems, at the current time, an untenable approach.

DNA analysis of dental pulp to link incinerated remains of homicide victim to crime scene.

PubMed

Sweet, D J; Sweet, C H

1995-03-01

Teeth endure postmortem degradation and extreme changes in ambient temperature and pressure better than most human tissues. This ability to resist deterioration allows the teeth to be studied as a method of establishing the identity of a decedent. Additionally, dental hard tissues, and in some instances soft tissues, may provide investigators with other sources of forensic data. In this case, a female homicide victim was transported to a location where her remains were burned. The high temperatures of a gasoline fire effectively incinerated the body precluding deoxyribonucleic acid (DNA) analysis from conventional sites. However, most of the teeth survived the conflagration. They were used to identify the victim. Additionally, the dental pulps were found to be an excellent source of high molecular weight genomic DNA. This proved to be an effective method to link the victim's body to biological evidence recovered from the site of the murder.

Regulation and Measurement of the Heat Generated by Automatic Tooth Preparation in a Confined Space.

PubMed

Yuan, Fusong; Zheng, Jianqiao; Sun, Yuchun; Wang, Yong; Lyu, Peijun

2017-06-01

The aim of this study was to assess and regulate heat generation in the dental pulp cavity and circumambient temperature around a tooth during laser ablation with a femtosecond laser in a confined space. The automatic tooth preparing technique is one of the traditional oral clinical technology innovations. In this technique, a robot controlled an ultrashort pulse laser to automatically complete the three-dimensional teeth preparing in a confined space. The temperature control is the main measure for protecting the tooth nerve. Ten tooth specimens were irradiated with a femtosecond laser controlled by a robot in a confined space to generate 10 teeth preparation. During the process, four thermocouple sensors were used to record the pulp cavity and circumambient environment temperatures with or without air cooling. A statistical analysis of the temperatures was performed between the conditions with and without air cooling (p < 0.05). The recordings showed that the temperature with air cooling was lower than that without air cooling and that the heat generated in the pulp cavity was lower than the threshold for dental pulp damage. These results indicate that femtosecond laser ablation with air cooling might be an appropriate method for automatic tooth preparing.

Current Advance and Future Prospects of Tissue Engineering Approach to Dentin/Pulp Regenerative Therapy

PubMed Central

Gong, Ting; Heng, Boon Chin; Lo, Edward Chin Man; Zhang, Chengfei

2016-01-01

Recent advances in biomaterial science and tissue engineering technology have greatly spurred the development of regenerative endodontics. This has led to a paradigm shift in endodontic treatment from simply filling the root canal systems with biologically inert materials to restoring the infected dental pulp with functional replacement tissues. Currently, cell transplantation has gained increasing attention as a scientifically valid method for dentin-pulp complex regeneration. This multidisciplinary approach which involves the interplay of three key elements of tissue engineering—stem cells, scaffolds, and signaling molecules—has produced an impressive number of favorable outcomes in preclinical animal studies. Nevertheless, many practical hurdles need to be overcome prior to its application in clinical settings. Apart from the potential health risks of immunological rejection and pathogenic transmission, the lack of a well-established banking system for the isolation and storage of dental-derived stem cells is the most pressing issue that awaits resolution and the properties of supportive scaffold materials vary across different studies and remain inconsistent. This review critically examines the classic triad of tissue engineering utilized in current regenerative endodontics and summarizes the possible techniques developed for dentin/pulp regeneration. PMID:27069484

A novel whole tooth-in-jaw-bone culture of rat molars: morphological, immunohistochemical, and laser capture microdissection analysis.

PubMed

Chokechanachaisakul, Uraiwan; Kaneko, Tomoatsu; Yamanaka, Yusuke; Okiji, Takashi; Suda, Hideaki

2012-10-01

In conventional whole-tooth culture systems, limitation exists regarding maintenance of the vitality of the dental pulp, because this tissue is encased in rigid dentin walls that hinder nutrition supply. We here report a whole tooth-in-jaw-bone culture system of rat mandibular first molars, where transcardiac perfusion with culture medium was carried out before placement of the jaw bone into culture medium, aiming to facilitate longer time preservation of the dental pulp tissue. Following 7 days of culture, the pulp tissues were analyzed by histology and immunohistochemistry to ED2 (antiresident macrophage). ED2-positive macrophages were also analyzed for their Class II MHC, interleukin-6 (IL-6), and p53 mRNA expression levels by means of immune-laser capture microdissection (immune-LCM). Dentin sialophosphoprotein (DSPP) mRNA expression in odontobalstic layer was also examined by LCM. Teeth cultured following saline-perfusion and nonperfusion served as cultured controls. Normal teeth also served as noncultured controls. Histological examination demonstrated that the structure of the pulp tissue was well preserved in the medium-perfused explants in contrast to the cultured control groups. The Class II MHC, IL-6, and p53 mRNA expression levels of ED2-positive cells and DSPP expression levels of odontoblastic layer tissues in the pulp of medium-perfused explants were not significantly different from those in the noncultured normal teeth. In conclusion, the structural integrity and mRNA expression in the pulp were maintained at the in vivo level in the ex vivo whole tooth-in-jaw-bone culture system. The system may lay the foundation for studies aiming at defining further histological and molecular mechanism of the pulp. Copyright © 2012 Wiley Periodicals, Inc.

Mesenchymal stem cells derived from inflamed dental pulpal and gingival tissue: a potential application for bone formation.

PubMed

Tomasello, Laura; Mauceri, Rodolfo; Coppola, Antonina; Pitrone, Maria; Pizzo, Giuseppe; Campisi, Giuseppina; Pizzolanti, Giuseppe; Giordano, Carla

2017-08-01

Chronic periodontal disease is an infectious disease consisting of prolonged inflammation of the supporting tooth tissue and resulting in bone loss. Guided bone regeneration procedures have become common and safe treatments in dentistry, and in this context dental stem cells would represent the ideal solution as autologous cells. In this study, we verified the ability of dental pulp mesenchymal stem cells (DPSCs) and gingival mesenchymal stem cells (GMSCs) harvested from periodontally affected teeth to produce new mineralized bone tissue in vitro, and compared this to cells from healthy teeth. To characterize DPSCs and GMSCs, we assessed colony-forming assay, immunophenotyping, mesenchymal/stem cell phenotyping, stem gene profiling by means of flow cytometry, and quantitative polymerase chain reaction (qPCR). The effects of proinflammatory cytokines on mesenchymal stem cell (MSC) proliferation and differentiation potential were investigated. We also observed participation of several heat shock proteins (HSPs) and actin-depolymerizing factors (ADFs) during osteogenic differentiation. DPSCs and GMSCs were successfully isolated both from periodontally affected dental tissue and controls. Periodontally affected dental MSCs proliferated faster, and the inflamed environment did not affect MSC marker expressions. The calcium deposition was higher in periodontally affected MSCs than in the control group. Proinflammatory cytokines activate a cytoskeleton remodeling, interacting with HSPs including HSP90 and HSPA9, thioredoxin-1, and ADFs such as as profilin-1, cofilin-1, and vinculin that probably mediate the increased acquisition in the inflamed environment. Our findings provide evidence that periodontally affected dental tissue (both pulp and gingiva) can be used as a source of MSCs with intact stem cell properties. Moreover, we demonstrated that the osteogenic capability of DPSCs and GMSCs in the test group was not only preserved but increased by the overexpression of several proinflammatory cytokine-dependent chaperones and stress response proteins.

Pathological investigation of caries and occlusal pulpar exposure in donkey cheek teeth using computerised axial tomography with histological and ultrastructural examinations.

PubMed

Toit, Nicole du; Burden, Faith A; Kempson, Sue A; Dixon, Padraic M

2008-12-01

Post-mortem examination of 16 donkey cheek teeth (CT) with caries (both peripheral and infundibular) and pulpar exposure were performed using computerised axial tomography (CAT), histology and scanning electron microscopy. CAT imaging was found to be useful to assess the presence and extent of caries and pulp exposure in individual donkey CT. Histology identified the loss of occlusal secondary dentine, and showed pulp necrosis in teeth with pulpar exposure. Viable pulp was present more apically in one exposed pulp horn, with its occlusal aspect sealed off from the exposed aspect of the pulp horn by a false pulp stone. Scanning electron microscopy showed the amelo-cemental junction to be a possible route of bacterial infection in infundibular cemental caries. The basic pathogenesis of dental caries in donkeys appears very similar to its description in other species.

Human dental pulp stem cells: Applications in future regenerative medicine

PubMed Central

Potdar, Pravin D; Jethmalani, Yogita D

2015-01-01

Stem cells are pluripotent cells, having a property of differentiating into various types of cells of human body. Several studies have developed mesenchymal stem cells (MSCs) from various human tissues, peripheral blood and body fluids. These cells are then characterized by cellular and molecular markers to understand their specific phenotypes. Dental pulp stem cells (DPSCs) are having a MSCs phenotype and they are differentiated into neuron, cardiomyocytes, chondrocytes, osteoblasts, liver cells and β cells of islet of pancreas. Thus, DPSCs have shown great potentiality to use in regenerative medicine for treatment of various human diseases including dental related problems. These cells can also be developed into induced pluripotent stem cells by incorporation of pluripotency markers and use for regenerative therapies of various diseases. The DPSCs are derived from various dental tissues such as human exfoliated deciduous teeth, apical papilla, periodontal ligament and dental follicle tissue. This review will overview the information about isolation, cellular and molecular characterization and differentiation of DPSCs into various types of human cells and thus these cells have important applications in regenerative therapies for various diseases. This review will be most useful for postgraduate dental students as well as scientists working in the field of oral pathology and oral medicine. PMID:26131314

A Simplified and Systematic Method to Isolate, Culture, and Characterize Multiple Types of Human Dental Stem Cells from a Single Tooth.

PubMed

Bakkar, Mohammed; Liu, Younan; Fang, Dongdong; Stegen, Camille; Su, Xinyun; Ramamoorthi, Murali; Lin, Li-Chieh; Kawasaki, Takako; Makhoul, Nicholas; Pham, Huan; Sumita, Yoshinori; Tran, Simon D

2017-01-01

This chapter describes a simplified method that allows the systematic isolation of multiple types of dental stem cells such as dental pulp stem cells (DPSC), periodontal ligament stem cells (PDLSC), and stem cells of the apical papilla (SCAP) from a single tooth. Of specific interest is the modified laboratory approach to harvest/retrieve the dental pulp tissue by minimizing trauma to DPSC by continuous irrigation, reduction of frictional heat from the bur rotation, and reduction of the bur contact time with the dentin. Also, the use of a chisel and a mallet will maximize the number of live DPSC for culture. Steps demonstrating the potential for multiple cell differentiation lineages of each type of dental stem cell into either osteocytes, adipocytes, or chondrocytes are described. Flow cytometry, with a detailed strategy for cell gating and analysis, is described to verify characteristic markers of human mesenchymal multipotent stromal cells (MSC) from DPSC, PDLSC, or SCAP for subsequent experiments in cell therapy and in tissue engineering. Overall, this method can be adapted to any laboratory with a general setup for cell culture experiments.

RAC1 regulate tumor necrosis factor-α-mediated impaired osteogenic differentiation of dental pulp stem cells.

PubMed

Feng, Guijuan; Shen, Qijie; Lian, Min; Gu, Zhifeng; Xing, Jing; Lu, Xiaohui; Huang, Dan; Li, Liren; Huang, Shen; Wang, Yi; Zhang, Jinlong; Shi, Jiahai; Zhang, Dongmei; Feng, Xingmei

2015-09-01

Human dental pulp contains a rapidly proliferative subpopulation of precursor cells termed dental pulp stem cells (DPSCs) that show self-renewal and multilineage differentiation, including neurogenic, chondrogenic, osteogenic and adipogenic. We previously reported that tomuor necrosis factor-α (TNF-α) (10 ng/mL) triggered osteogenic differentiation of human DPSCs via the nuclear factor-κB (NF-κB) signaling pathway. While previous studies showed that cells treated with TNF-α at higher concentrations showed decreased osteogenic differentiation capability. In this study we analyze the function of TNF-α (100 ng/mL) on osteogenic differentiation of human DPSCs for the first time and identify the underlying molecule mechanisms. Our data revealed that TNF-α with higher concentration significantly reduced mineralization and the expression of bone morphogenetic protein 2 (BMP2), alkaline phosphatase (ALP) and runt-related transcription factor 2 (RUNX2). Further, we revealed that TNF-α could suppress the osteogenic differentiation of DPSCs via increasing the expression of RAC1, which could activate the Wnt/β-catenin signaling pathway and liberate β-catenin to translocate into the nucleus. Genetic silencing of RAC1 expression using siRNA restored osteogenic differentiation of DPSCs. Our findings may provide a potential approach to bone regeneration in inflammatory microenvironments. © 2015 Japanese Society of Developmental Biologists.

Dental Stem Cell Migration on Pulp Ceiling Cavities Filled with MTA, Dentin Chips, or Bio-Oss

PubMed Central

Lymperi, Stefania; Taraslia, Vasiliki; Tsatsoulis, Ioannis N.; Samara, Athina; Agrafioti, Anastasia; Anastasiadou, Ema; Kontakiotis, Evangelos

2015-01-01

MTA, Bio-Oss, and dentin chips have been successfully used in endodontics. The aim of this study was to assess the adhesion and migration of dental stem cells on human pulp ceiling cavities filled with these endodontic materials in an experimental model, which mimics the clinical conditions of regenerative endodontics. Cavities were formed, by a homemade mold, on untouched third molars, filled with endodontic materials, and observed with electron microscopy. Cells were seeded on cavities' surface and their morphology and number were analysed. The phenomenon of tropism was assessed in a migration assay. All three materials demonstrated appropriate microstructures for cell attachment. Cells grew on all reagents, but they showed a differential morphology. Moreover, variations were observed when comparing cells numbers on cavity's filling versus the surrounding dentine disc. The highest number of cells was recorded on dentin chips whereas the opposite was true for Bio-Oss. This was confirmed in the migration assay where a statistically significant lower number of cells migrated towards Bio-Oss as compared to MTA and dentin chips. This study highlights that MTA and dentin chips have a greater potential compared to Bio-Oss regarding the attraction of dental stem cells and are good candidates for bioengineered pulp regeneration. PMID:26146613

Human dental pulp stem cells produce mineralized matrix in 2D and 3D cultures

PubMed Central

Riccio, M.; Resca, E.; Maraldi, T.; Pisciotta, A.; Ferrari, A.; Bruzzesi, G.; De Pol, A.

2010-01-01

The aim of this study was to characterize the in vitro osteogenic differentiation of dental pulp stem cells (DPSCs) in 2D cultures and 3D biomaterials. DPSCs, separated from dental pulp by enzymatic digestion, and isolated by magnetic cell sorting were differentiated toward osteogenic lineage on 2D surface by using an osteogenic medium. During differentiation process, DPSCs express specific bone proteins like Runx-2, Osx, OPN and OCN with a sequential expression, analogous to those occurring during osteoblast differentiation, and produce extracellular calcium deposits. In order to differentiate cells in a 3D space that mimes the physiological environment, DPSCs were cultured in two distinct bioscaffolds, Matrigel™ and Collagen sponge. With the addition of a third dimension, osteogenic differentiation and mineralized extracellular matrix production significantly improved. In particular, in Matrigel™ DPSCs differentiated with osteoblast/osteocyte characteristics and connected by gap junction, and therefore formed calcified nodules with a 3D intercellular network. Furthermore, DPSCs differentiated in collagen sponge actively secrete human type I collagen micro-fibrils and form calcified matrix containing trabecular-like structures. These neo-formed DPSCs-scaffold devices may be used in regenerative surgical applications in order to resolve pathologies and traumas characterized by critical size bone defects. PMID:21263745

Ionizing radiation induces senescence and differentiation of human dental pulp stem cells.

PubMed

Havelek, R; Soukup, T; Ćmielová, J; Seifrtová, M; Suchánek, J; Vávrová, J; Mokrý, J; Muthná, D; Řezáčová, M

2013-01-01

Head and neck cancer is one of the most common cancers in Europe. Many current anti-cancer treatments, including ionizing radiation, induce apoptosis via DNA damage. Unfortunately, such treatments are non-selective to cancer cells and produce similar toxicity in normal cells, including adult stem cells. One of the fundamental properties of an adult stem cell is that it does not have any tissue-specific structures that allow it to perform specialized functions. However, under certain stimuli, unspecialized adult stem cells can give rise to specialized cells to generate replacements for cells that are lost during one's life or due to injury or disease. Nevertheless, specialization of stem cells must be controlled by specific milieu and also initiated at the proper time, making the entire process beneficial for tissue recovery and maintaining it for a long time. In this paper we assess whether irradiated dental pulp stem cells have maintained open their options to mature into specialized cells, or whether they have lost their unspecialized (immature) state following irradiation. Our findings showed radiation-induced premature differentiation of dental pulp stem cells towards odonto-/osteoblast lineages in vitro. Matrix calcification was visualized from Day 6 or Day 9 following irradiation of cells expressing low or high levels of CD146, respectively.

Indirect immobilized Jagged1 suppresses cell cycle progression and induces odonto/osteogenic differentiation in human dental pulp cells.

PubMed

Manokawinchoke, Jeeranan; Nattasit, Praphawi; Thongngam, Tanutchaporn; Pavasant, Prasit; Tompkins, Kevin A; Egusa, Hiroshi; Osathanon, Thanaphum

2017-08-31

Notch signaling regulates diverse biological processes in dental pulp tissue. The present study investigated the response of human dental pulp cells (hDPs) to the indirect immobilized Notch ligand Jagged1 in vitro. The indirect immobilized Jagged1 effectively activated Notch signaling in hDPs as confirmed by the upregulation of HES1 and HEY1 expression. Differential gene expression profiling using an RNA sequencing technique revealed that the indirect immobilized Jagged1 upregulated genes were mainly involved in extracellular matrix organization, disease, and signal transduction. Downregulated genes predominantly participated in the cell cycle, DNA replication, and DNA repair. Indirect immobilized Jagged1 significantly reduced cell proliferation, colony forming unit ability, and the number of cells in S phase. Jagged1 treated hDPs exhibited significantly higher ALP enzymatic activity, osteogenic marker gene expression, and mineralization compared with control. Pretreatment with a γ-secretase inhibitor attenuated the Jagged1-induced ALP activity and mineral deposition. NOTCH2 shRNA reduced the Jagged1-induced osteogenic marker gene expression, ALP enzymatic activity, and mineral deposition. In conclusion, indirect immobilized Jagged1 suppresses cell cycle progression and induces the odonto/osteogenic differentiation of hDPs via the canonical Notch signaling pathway.

Potential Roles of Dental Pulp Stem Cells in Neural Regeneration and Repair

PubMed Central

Luo, Lihua; Wang, Xiaoyan; Key, Brian; Lee, Bae Hoon

2018-01-01

This review summarizes current advances in dental pulp stem cells (DPSCs) and their potential applications in the nervous diseases. Injured adult mammalian nervous system has a limited regenerative capacity due to an insufficient pool of precursor cells in both central and peripheral nervous systems. Nerve growth is also constrained by inhibitory factors (associated with central myelin) and barrier tissues (glial scarring). Stem cells, possessing the capacity of self-renewal and multicellular differentiation, promise new therapeutic strategies for overcoming these impediments to neural regeneration. Dental pulp stem cells (DPSCs) derive from a cranial neural crest lineage, retain a remarkable potential for neuronal differentiation, and additionally express multiple factors that are suitable for neuronal and axonal regeneration. DPSCs can also express immunomodulatory factors that stimulate formation of blood vessels and enhance regeneration and repair of injured nerve. These unique properties together with their ready accessibility make DPSCs an attractive cell source for tissue engineering in injured and diseased nervous systems. In this review, we interrogate the neuronal differentiation potential as well as the neuroprotective, neurotrophic, angiogenic, and immunomodulatory properties of DPSCs and its application in the injured nervous system. Taken together, DPSCs are an ideal stem cell resource for therapeutic approaches to neural repair and regeneration in nerve diseases. PMID:29853908

Selective interference with pacemaker activity by electrical dental devices.

PubMed

Miller, C S; Leonelli, F M; Latham, E

1998-01-01

We sought to determine whether electromagnetic interference with cardiac pacemakers occurs during the operation of contemporary electrical dental equipment. Fourteen electrical dental devices were tested in vitro for their ability to interfere with the function of two Medtronics cardiac pacemakers (one a dual-chamber, bipolar Thera 7942 pacemaker, the other a single-chamber, unipolar Minix 8340 pacemaker). Atrial and ventricular pacemaker output and electrocardiographic activity were monitored by means of telemetry with the use of a Medtronics 9760/90 programmer. Atrial and ventricular pacing were inhibited by electromagnetic interference produced by the electrosurgical unit up to a distance of 10 cm, by the ultrasonic bath cleaner up to 30 cm, and by the magnetorestrictive ultrasonic scalers up to 37.5 cm. In contrast, operation of the amalgamator, electric pulp tester, composite curing light, dental handpieces, electric toothbrush, microwave oven, dental chair and light, ENAC ultrasonic instrument, radiography unit, and sonic scaler did not alter pacing rate or rhythm. These results suggest that certain electrosurgical and ultrasonic instruments may produce deleterious effects in medically fragile patients with cardiac pacemakers.

Stimulation of EphB2/ephrin-B1 signalling by tumour necrosis factor alpha in human dental pulp stem cells.

PubMed

Zhu, Lifang; Dissanayaka, Waruna Lakmal; Green, David William; Zhang, Chengfei

2015-04-01

The aim of this study was to investigate whether in vitro stimulation of dental pulp stem cells (DPSCs) by tumour necrosis factor alpha (TNF-α) would induce secretion of EphB2/ephrin-B1 signalling. Dental pulp stem cells isolated from human dental pulp were treated with TNF-α (5-100 ng/ml) over 2-48 h. EphB2/ephrin-B1 mRNA and protein levels were measured by real-time polymerase chain reaction (RT-PCR) and western blot analysis respectively. Additionally, DPSCs were pre-incubated with TNF-α receptor neutralizing antibodies or infected with nuclear factor-kappa B (NF-ĸB) inhibitor, p38 MAPK inhibitor, Jun N-terminal kinase (JNK) inhibitor and MEK inhibitor before TNF-α treatment. Results were analysed by one-way ANOVA. Tumour necrosis factor alpha increased EphB2 mRNA expression in DPSCs at concentrations up to 20 ng/ml and ephrin-B1 at concentrations up to 40 ng/ml (P < 0.05). Its mRNA expression reached maximum at 24 h when treated with TNF-α at 20 ng/ml (P < 0.05). EphB2/ephrin-B1 protein expression levels were high at 16 and 24 h as shown by western blotting. Neutralizing antibodies for TNFR1/2 receptors down-regulated EphB2/ephrin-B1 mRNA expression (P < 0.05) and ephrin-B1 protein expression, but not EphB2 protein expression. JNK-inhibitor inhibited EphB2 mRNA expression only (P < 0.05). EphB2/ephrin-B1 were invoked in DPSCs with TNF-α treatment via the JNK-dependent pathway, but not NF-ĸB, p38 MAPK or MEK signalling. © 2015 John Wiley & Sons Ltd.

Transcriptome comparison of human neurons generated using induced pluripotent stem cells derived from dental pulp and skin fibroblasts.

PubMed

Chen, Jian; Lin, Mingyan; Foxe, John J; Pedrosa, Erika; Hrabovsky, Anastasia; Carroll, Reed; Zheng, Deyou; Lachman, Herbert M

2013-01-01

Induced pluripotent stem cell (iPSC) technology is providing an opportunity to study neuropsychiatric disorders through the capacity to grow patient-specific neurons in vitro. Skin fibroblasts obtained by biopsy have been the most reliable source of cells for reprogramming. However, using other somatic cells obtained by less invasive means would be ideal, especially in children with autism spectrum disorders (ASD) and other neurodevelopmental conditions. In addition to fibroblasts, iPSCs have been developed from cord blood, lymphocytes, hair keratinocytes, and dental pulp from deciduous teeth. Of these, dental pulp would be a good source for neurodevelopmental disorders in children because obtaining material is non-invasive. We investigated its suitability for disease modeling by carrying out gene expression profiling, using RNA-seq, on differentiated neurons derived from iPSCs made from dental pulp extracted from deciduous teeth (T-iPSCs) and fibroblasts (F-iPSCs). This is the first RNA-seq analysis comparing gene expression profiles in neurons derived from iPSCs made from different somatic cells. For the most part, gene expression profiles were quite similar with only 329 genes showing differential expression at a nominally significant p-value (p<0.05), of which 63 remained significant after correcting for genome-wide analysis (FDR <0.05). The most striking difference was the lower level of expression detected for numerous members of the all four HOX gene families in neurons derived from T-iPSCs. In addition, an increased level of expression was seen for several transcription factors expressed in the developing forebrain (FOXP2, OTX1, and LHX2, for example). Overall, pathway analysis revealed that differentially expressed genes that showed higher levels of expression in neurons derived from T-iPSCs were enriched for genes implicated in schizophrenia (SZ). The findings suggest that neurons derived from T-iPSCs are suitable for disease-modeling neuropsychiatric disorder and may have some advantages over those derived from F-iPSCs.

Insulin-Like Growth Factor 1 Receptor and p38 Mitogen-Activated Protein Kinase Signals Inversely Regulate Signal Transducer and Activator of Transcription 3 Activity to Control Human Dental Pulp Stem Cell Quiescence, Propagation, and Differentiation

PubMed Central

Vandomme, Jerome; Touil, Yasmine; Ostyn, Pauline; Olejnik, Cecile; Flamenco, Pilar; El Machhour, Raja; Segard, Pascaline; Masselot, Bernadette; Bailliez, Yves; Formstecher, Pierre

2014-01-01

Dental pulp stem cells (DPSCs) remain quiescent until activated in response to severe dental pulp damage. Once activated, they exit quiescence and enter regenerative odontogenesis, producing reparative dentin. The factors and signaling molecules that control the quiescence/activation and commitment to differentiation of human DPSCs are not known. In this study, we determined that the inhibition of insulin-like growth factor 1 receptor (IGF-1R) and p38 mitogen-activated protein kinase (p38 MAPK) signaling commonly activates DPSCs and promotes their exit from the G0 phase of the cell cycle as well as from the pyronin Ylow stem cell compartment. The inhibition of these two pathways, however, inversely determines DPSC fate. In contrast to p38 MAPK inhibitors, IGF-1R inhibitors enhance dental pulp cell sphere-forming capacity and reduce the cells' colony-forming capacity without inducing cell death. The inverse cellular changes initiated by IGF-1R and p38 MAPK inhibitors were accompanied by inverse changes in the levels of active signal transducer and activator of transcription 3 (STAT3) factor, inactive glycogen synthase kinase 3, and matrix extracellular phosphoglycoprotein, a marker of early odontoblast differentiation. Our data suggest that there is cross talk between the IGF-1R and p38 MAPK signaling pathways in DPSCs and that the signals provided by these pathways converge at STAT3 and inversely regulate its activity to maintain quiescence or to promote self-renewal and differentiation of the cells. We propose a working model that explains the possible interactions between IGF-1R and p38 MAPK at the molecular level and describes the cellular consequences of these interactions. This model may inspire further fundamental study and stimulate research on the clinical applications of DPSC in cellular therapy and tissue regeneration. PMID:24266654

Heat transfer properties and thermal cure of glass-ionomer dental cements.

PubMed

Gavic, Lidia; Gorseta, Kristina; Glavina, Domagoj; Czarnecka, Beata; Nicholson, John W

2015-10-01

Under clinical conditions, conventional glass-ionomer dental cements can be cured by application of heat from dental cure lamps, which causes acceleration in the setting. In order for this to be successful, such heat must be able to spread sufficiently through the cement to enhance cure, but not transmit heat so effectively that the underlying dental pulp of the tooth is damaged. The current study was aimed at measuring heat transfer properties of modern restorative glass-ionomers to determine the extent to which they meet these twin requirements. Three commercial glass ionomer cements (Ionofil Molar, Ketac Molar and Equia™ Fill) were used in association with three different light emitting diode cure lamps designed for clinical use. In addition, for each cement, one set of specimens was allowed to cure without application of a lamp. Temperature changes were measured at three different depths (2, 3 and 4 mm) after cure times of 20, 40 and 60 s. The difference among the tested groups was evaluated by ANOVA (P < 0.05) and post hoc Newman-Keuls test. All brands of glass-ionomer showed a small inherent setting exotherm in the absence of heat irradiation, but much greater temperature increases when exposed to the cure lamp. However, temperature rises did not exceed 12.9 °C. Application of the cure lamp led to the establishment of a temperature gradient throughout each specimen. Differences were typically significant (P < 0.05) and did not reflect the nominal power of the lamps, because those lamps have variable cooling systems, and are designed to optimize light output, not heating effect. Because the thermal conductivity of glass-ionomers is low, temperature rises at 4 mm depths were much lower than at 2 mm. At no time did the temperature rise sufficiently to cause concern about potential damage to the pulp.

Doxycycline-encapsulated nanotube-modified dentin adhesives.

PubMed

Feitosa, S A; Palasuk, J; Kamocki, K; Geraldeli, S; Gregory, R L; Platt, J A; Windsor, L J; Bottino, M C

2014-12-01

This article presents details of fabrication, biological activity (i.e., anti-matrix metalloproteinase [anti-MMP] inhibition), cytocompatibility, and bonding characteristics to dentin of a unique doxycycline (DOX)-encapsulated halloysite nanotube (HNT)-modified adhesive. We tested the hypothesis that the release of DOX from the DOX-encapsulated nanotube-modified adhesive can effectively inhibit MMP activity. We incorporated nanotubes, encapsulated or not with DOX, into the adhesive resin of a commercially available bonding system (Scotchbond Multi-Purpose [SBMP]). The following groups were tested: unmodified SBMP (control), SBMP with nanotubes (HNT), and DOX-encapsulated nanotube-modified adhesive (HNT+DOX). Changes in degree of conversion (DC) and microtensile bond strength were evaluated. Cytotoxicity was examined on human dental pulp stem cells (hDPSCs). To prove the successful encapsulation of DOX within the adhesives-but, more important, to support the hypothesis that the HNT+DOX adhesive would release DOX at subantimicrobial levels-we tested the antimicrobial activity of synthesized adhesives and the DOX-containing eluates against Streptococcus mutans through agar diffusion assays. Anti-MMP properties were assessed via β-casein cleavage assays. Increasing curing times (10, 20, 40 sec) led to increased DC values. There were no statistically significant differences (p > .05) in DC within each increasing curing time between the modified adhesives compared to SBMP. No statistically significant differences in microtensile bond strength were noted. None of the adhesives eluates were cytotoxic to the human dental pulp stem cells. A significant growth inhibition of S. mutans by direct contact illustrates successful encapsulation of DOX into the experimental adhesive. More important, DOX-containing eluates promoted inhibition of MMP-1 activity when compared to the control. Collectively, our findings provide a solid background for further testing of encapsulated MMP inhibitors into the synthesis of therapeutic adhesives that may enhance the longevity of hybrid layers and the overall clinical performance of adhesively bonded resin composite restorations. © International & American Associations for Dental Research.

Multilineage potential and proteomic profiling of human dental stem cells derived from a single donor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patil, Rajreddy; Kumar, B. Mohana; Lee, Won-Jae

Dental tissues provide an alternative autologous source of mesenchymal stem cells (MSCs) for regenerative medicine. In this study, we isolated human dental MSCs of follicle, pulp and papilla tissue from a single donor tooth after impacted third molar extraction by excluding the individual differences. We then compared the morphology, proliferation rate, expression of MSC-specific and pluripotency markers, and in vitro differentiation ability into osteoblasts, adipocytes, chondrocytes and functional hepatocyte-like cells (HLCs). Finally, we analyzed the protein expression profiles of undifferentiated dental MSCs using 2DE coupled with MALDI-TOF-MS. Three types of dental MSCs largely shared similar morphology, proliferation potential, expression ofmore » surface markers and pluripotent transcription factors, and differentiation ability into osteoblasts, adipocytes, and chondrocytes. Upon hepatogenic induction, all MSCs were transdifferentiated into functional HLCs, and acquired hepatocyte functions by showing their ability for glycogen storage and urea production. Based on the proteome profiling results, we identified nineteen proteins either found commonly or differentially expressed among the three types of dental MSCs. In conclusion, three kinds of dental MSCs from a single donor tooth possessed largely similar cellular properties and multilineage potential. Further, these dental MSCs had similar proteomic profiles, suggesting their interchangeable applications for basic research and call therapy. - Highlights: • Isolated and characterized three types of human dental MSCs from a single donor. • MSCs of dental follicle, pulp and papilla had largely similar biological properties. • All MSCs were capable of transdifferentiating into functional hepatocyte-like cells. • 2DE proteomics with MALDI-TOF/MS identified 19 proteins in three types of MSCs. • Similar proteomic profiles suggest interchangeable applications of dental MSCs.« less

Acoustic comparison of Er,Cr:YSGG laser and dental high speed handpiece for primary anterior tooth preparation

NASA Astrophysics Data System (ADS)

Jorden, Monserrat; Chen, Jung-Wei; Easley, Elisabeth; Li, Yiming; Kurti, R. Steven

The acoustics of a dental hard tissue laser (Er,Cr:YSGG laser, Waterlase MD, Biolase, USA) and a traditional dental high speed hand piece (Midwest®, Dentsply International, USA) were compared in vitro using a simple approach that can be easily adapted for in vivo studies. Thirty one extracted caries and restoration free primary anterior teeth were selected. These teeth were sectioned along a symmetry axis to give two identical halves for use in a split study. These halves were randomly assigned to either the laser (experimental) or the high speed (control) group. A miniature electret microphone was coupled to the sample using a polymer and used to collect the acoustic signal at the interface of the pulp chamber. This signal was captured periodically by a digitizing oscilloscope and multiple traces were stored for subsequent analysis. 2x1x1mm3 preparations were made according to manufacturers recommendations for the given method. Each cavity was prepared by the same clinician and calibration tests were performed to ensure consistency. The measurements indicated that the peak acoustic pressures as well as cumulative acoustic effects (due to duty cycle) were significantly higher (P<0.001, T-test) with the dental hand piece than with the dental laser. Our study suggests the need for further investigations into the neurological implications of acoustic effects in dental patient care such as pain studies.

Evaluation of Nd:YAG laser on partial oxygen saturation of pulpal blood in anterior hypersensitive teeth.

PubMed

Birang, Reza; Kaviani, Naser; Mohammadpour, Mehdi; Abed, Ahmad Moghareh; Gutknecht, Norbert; Mir, Maziar

2008-07-01

Dentine hypersensitivity has of long been known to be a common clinical problem in dental practices. Lasers have recently come to play a prominent role in the treatment of this disorder. They might, however, cause dental pulp damage. This study was conducted to evaluate the effect of Nd:yttrium-aluminum-garnet (YAG) laser on partial oxygen saturation of pulpal blood in sensitive anterior teeth. In this clinical trial, 65 hypersensitive teeth were selected and randomly allocated to two groups. The study group involved Nd:YAG laser treatment, while no treatment was employed for the control group. Using a pulse oximetry system, evaluations were preformed of the partial oxygen saturation in the pulpal blood before, immediately after, 1 week after, and 1 month after the treatment. The results were analyzed using the SPSS software and repeated-measures analysis of variance and paired-samples t tests. The mean partial oxygen saturation of the blood was found to be 85.4% in the study group, which was not significantly different from that of the control group. No significant differences were observed in the control group between the means obtained from pretreatment and post-treatment intervals (P > 0.05). The Post-treatment partial oxygen saturation mean rose to 89.3% (P = 0.001) and remained constant throughout the following week after it. However, no significant differences were found between the pretreatment partial oxygen saturation mean and the same measurement 1 month after treatment (P = 0.702). Nd:YAG laser therapy for dentine desensitization of anterior teeth caused no persistent changes in the partial oxygen saturation of pulpal blood. It may, therefore, be concluded that the diffusion of heat induced by the Nd:YAG laser into the pulp within the limit of the desensitization parameters cause no irreversible damages in the dental pulp.

Zirconia-incorporated zinc oxide eugenol has improved mechanical properties and cytocompatibility with human dental pulp stem cells.

PubMed

Jun, Soo Kyung; Kim, Hae-Won; Lee, Hae-Hyoung; Lee, Jung-Hwan

2018-01-01

Zinc oxide eugenol (ZOE) is widely used as a therapeutic dental restorative material. However, ZOE has poor mechanical properties and high cytotoxicity toward human dental pulp stem cells (hDPSCs) due to the release of Zn ions. In this study, zirconia-incorporated ZOE (ZZrOE) was developed to reduce the cytotoxicity and improve the mechanical properties of ZOE with sustained therapeutic effects on inflamed hDPSCs in terms of inflammatory gene expression levels compared with those of the original material. After the setting time and mechanical properties of ZZrOE incorporating varying amounts of zirconia (0, 5, 10, and 20wt% in powder) were characterized, the surface morphology and composition of the resulting ZZrOE materials were investigated. The ions and chemicals released into the cell culture medium from ZOE and ZZrOE (3cm 2 /mL) were measured by inductively coupled plasma atomic emission spectroscopy and gas chromatography, respectively. After testing cytotoxicity against hDPSCs using the above extracts, the therapeutic effects on lipopolysaccharide-inflamed hDPSCs in terms of compromising the upregulation of inflammatory response-related mRNA expression were tested using real-time PCR. ZZrOE 20% exhibited increased compressive strength (∼45%), 3-point flexural strength (∼150%) and hardness (∼75%), as well as a similar setting time (∼90%), compared with those of ZOE. After the rough surface of ZZrOE was observed, significantly fewer released Zn ions and eugenol (∼40% of that from ZOE) were detected in ZZrOE 20%. ZZrOE showed less cytotoxicity because of the lower amount of Zn ions released from ZOE while showing sustained inhibition of inflammatory marker (e.g., interleukin 1β, 6 and 8) mRNA levels. The improved mechanical properties and cytocompatibility, as well as the sustained therapeutic effects on inflamed hDPSCs, were investigated in ZZrOE compared with those of ZOE. Therefore, ZZrOE has the potential to be used as an alternative to ZOE as a dental restorative material. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Pulpotomies with CO2 laser in dogs

NASA Astrophysics Data System (ADS)

Figueiredo, Jose A. P.; Chavantes, Maria C.; Gioso, Marco A.; Pesce, Hildeberto F.; Jatene, Adib D.

1995-05-01

The aim of this study was to evaluate the clinical aspects of dental pulps submitted to shallow pulpotomy followed by CO2 laser radiation at five different procedures. For this purpose, initially 66 dogs' teeth were opened and about 2 or 3 mm of coronal dental pulp was removed. Continuous irrigation with saline solution was implemented. The teeth were randomly divided into 6 groups of 11 each. After cessation of bleeding, in group I, CO2 laser (Xanar-20, USA) was irradiated for 1 second at a power of 5 watts; in group II, 2 seconds at 3 watts; in Group III, 2 seconds at 5 watts; in Group IV, 1 second at 3 watts; in Group V, a continuous mode at 3 watts; Group VI served as a control, with no laser irradiation. The results showed no clinical differences between the 3 W and 5 W powers. Time period of irradiation exposition influenced definitively the clinical appearance of the dental pulps. Groups I and IV (1 second) were unable to stop the bleeding, which persisted over 15 minutes for all teeth. This may be due to the intense heat generated by CO2 laser, causing vasodilatation. Groups II and III displayed a similar appearance, but bleeding stopped in about 10 minutes. Group V (continuous mode) had no bleeding after irradiation, but a plasma-like liquid would come out for almost 2 minutes. When comparing to the control (Group VI), all the pulps would assume a jelly-like aspect, with black granulated tissue on the surface, covering totally the pulps of Group V and partially the other groups. The histological results will be discussed in a further study. From the data obtained, it seems that CO2 laser irradiation for pulpotomies should be done in a continuous mode, for clinical convenience in terms of time taken and effective irradiation.

Complete pulpodentin complex regeneration by modulating the stiffness of biomimetic matrix.

PubMed

Qu, Tiejun; Jing, Junjun; Ren, Yinshi; Ma, Chi; Feng, Jian Q; Yu, Qing; Liu, Xiaohua

2015-04-01

Dental caries is one of the most prevalent chronic diseases in all populations. The regeneration of dentin-pulp tissues (pulpodentin) using a scaffold-based tissue engineering strategy is a promising approach to replacing damaged dental structures and restoring their biological functions. However, the current scaffolding design for pulpodentin regeneration does not take into account the distinct difference between pulp and dentin, therefore, is incapable of regenerating a complete tooth-like pulpodentin complex. In this study, we determined that scaffolding stiffness is a crucial biophysical cue to modulate dental pulp stem cell (DPSC) differentiation. The DPSCs on a high-stiffness three-dimensional (3D) nanofibrous gelatin (NF-gelatin) scaffold had more organized cytoskeletons and a larger spreading area than on a low-stiffness NF-gelatin scaffold. In the same differentiation medium, a high-stiffness NF-gelatin facilitated DPSC differentiation to form a mineralized tissue, while a low-stiffness NF-gelatin promoted a soft pulp-like tissue formation from the DPSCs. A facile method was then developed to integrate the low- and high-stiffness gelatin matrices into a single scaffold (S-scaffold) for pulpodentin complex regeneration. A 4-week in vitro experiment showed that biomineralization took place only in the high-stiffness peripheral area and formed a ring-like structure surrounding the non-mineralized central area of the DPSC/S-scaffold construct. A complete pulpodentin complex similar to natural pulpodentin was successfully regenerated after subcutaneous implantation of the DPSC/S-scaffold in nude mice for 4weeks. Histological staining showed a significant amount of extracellular matrix (ECM) formation in the newly formed pulpodentin complex, and a number of blood vessels were observed in the pulp tissue. Taken together, this work shows that modulating the stiffness of the NF-gelatin scaffold is a successful approach to regenerating a complete tooth-like pulpodentin complex. Published by Elsevier Ltd.

Paediatric dentistry in the new millennium: 4. Cost-effective restorative techniques for primary molars.

PubMed

Duggal, M S; Gautam, S K; Nichol, R; Robertson, A J

2003-10-01

In the fourth article in this series the techniques for carrying out pulp therapy and stainless steel restoration in primary molars are discussed. Early pulp involvement in primary molars means that pulp therapy and the use of appropriate coronal restoration, such as stainless steel crowns, are indispensable if repetitive restoration of primary molars is to be avoided. These techniques themselves are not difficult to carry out once the child's co-operation is established and should be well within the capability of any dentist with an interest in the dental care of children.

Oral cavity evaluation and dental chart registration of coati (Nasua nasua) in captivity.

PubMed

Freitas, Elisângela P; Rahal, Sheila C; Teixeira, Carlos R; Teixeira, Rodrigo H F; Mendes, Guilherme M; Gioso, Marco A

2008-06-01

The aims of this study were to develop a dental evaluate any oral cavity disease, develop gypsum models of the dental arches, and to register the occlusions found in coatis (Nasua nasua) in captivity Formulation of the dental chart was assisted by intraoral radiographs from the head of an adult coati cadaver of the same species with the following dental formula.: I 3/3, C 1/1, P 4/3, M 2/2. Seven live coatis of the Nasua nasua species were evaluated. Five of the seven coatis presented with various dental abnormalities as follows: dental plaque (71.4 0%), gingivitis (71.4 %), periodontitis (57.1 %), dental stain (42.9 %), dental abrasion (57.1 %), dental fracture (57.1 %), pulp exposure (42.9 %), malocclusion (57.1 %) and supernumerary teeth (14.2 %).

Vital pulp therapy using calcium-enriched mixture: An evidence-based review

PubMed Central

Asgary, Saeed; Ahmadyar, Maryam

2013-01-01

Worldwide, casecontrol studies have revealed that the treatment outcomes of root canal therapy (RCT) are generally favorable; however, the overall epidemiological success rate of RCT in the general population is relatively low. On the other hand, vitality of dental pulp is a key factor in the long-term prognosis of permanent teeth; in recent years, vital pulp therapy (VPT) has received significant consideration as it has been revealed that the inflamed pulp has the potential to heal. In this review article, the current best evidence with regard to VPT using calcium-enriched mixture (CEM) cement in human permanent/primary teeth is discussed. A strategy based on a search using keywords for CEM cement as well as VPT was applied. PMID:23716958

Review of Spaceflight Dental Emergencies

NASA Technical Reports Server (NTRS)

Menon, Anil

2012-01-01

All exploration class missions--extending beyond earth's orbit--differ from existing orbital missions by being of longer duration and often not having a means of evacuation. If an exploration mission extends beyond a year, then there will be a greater lapse since the crewmembers last terrestrial dental exams, which routinely occur each year. This increased time since professional dental care could increase the chance of a dental emergency such as intractable pain, dental decay requiring a temporary filling, crown replacement, exposed pulp, abscess, tooth avulsion, or toothache. Additionally, any dental emergency will have to be treated in-flight with available resources and personnel who may not have extensive training in dental care. Thus, dental emergencies are an important risk to assess in preparation for exploration missions.

Influence of zinc oxide quantum dots in the antibacterial activity and cytotoxicity of an experimental adhesive resin.

PubMed

Garcia, Isadora Martini; Leitune, Vicente Castelo Branco; Visioli, Fernanda; Samuel, Susana Maria Werner; Collares, Fabrício Mezzomo

2018-06-01

To evaluate the influence of zinc oxide quantum dots (ZnO QDs ) into an experimental adhesive resin regarding the antibacterial activity against Streptococcus mutans and the cytotoxicity against pulp fibroblasts. ZnO QDs were synthesized by sol-gel process and were incorporated into 2-hydroxyethyl methacrylate (HEMA). An experimental adhesive resin was formulated by mixing 66.6 wt.% bisphenol A glycol dimethacrylate (BisGMA) and 33.3 wt.% HEMA with a photoinitiator system as control group. HEMA containing ZnO QDs was used for test group formulation. For the antibacterial activity assay, a direct contact inhibition evaluation was performed with biofilm of Streptococcus mutans (NCTC 10449). The cytotoxicity assay was performed by Sulforhodamine B (SRB) colorimetric assay for cell density determination using pulp fibroblasts. Data were analyzed by Student's t-test (α = 0.05). The antibacterial activity assay indicated statistically significant difference between the groups (p = 0.003), with higher values of biofilm formation on the polymerized samples of control group and a reduction of more than 50% of biofilm formation on ZnO QDs group. No difference of pulp fibroblasts viability was found between the adhesives (p = 0.482). ZnO QDs provided antibacterial activity when doped into an experimental adhesive resin without cytotoxic effect for pulp fibroblasts. Thus, the use of ZnO QDs is a strategy to develop antibiofilm restorative polymers with non-agglomerated nanofillers. ZnO QDs are non-agglomerated nanoscale fillers for dental resins and may be a strategy to reduce biofilm formation at dentin/restoration interface with no cytotoxicity for pulp fibroblasts. Copyright © 2018 Elsevier Ltd. All rights reserved.

Nano-hydroxyapatite and calcium-enriched mixture for pulp capping of sound primary teeth: a randomized clinical trial.

PubMed

Haghgoo, Roza; Asgary, Saeed; Mashhadi Abbas, Fatemeh; Montazeri Hedeshi, Roshanak

2015-01-01

Nano-hydroxyapatite (NHA) has been used for regeneration of osseous defects. Calcium-enriched mixture (CEM) cement is also used for various dental treatments. This trial compared the efficacy of NHA and CEM cement for direct pulp capping (DPC) of sound primary teeth. In this randomized clinical trial with split-mouth design, after attaining informed consent, 20 sound primary canines scheduled for orthodontic extraction, were selected. After mechanical pulp exposure, the exposed site was capped with either NHA or CEM cement and then immediately restored with glass-ionomer and resin composite. The teeth were extracted after two months and examined histologically. Parameters of hard tissue bridge (HTB) formation, its type and quality as well as pulpal inflammation scores were compared between the two experimental groups. The data were analyzed using the Mann Whitney U and Fisher's exact test. The level of significance was set at 0.001. All CEM specimens showed inflammation score of 0 (less than 10%). However, in NHA group, inflammation scores of 0 (less than 10%), 1 (10%-30%) and 2 (30%-50%) were observed in 2 (20%), 4 (40%) and 4 (40%) specimens, respectively (P<0.001). HTB was formed in all CEM specimens while it was developed in 2 specimens of NHA (20%; P<0.001). All CEM specimens showed normal pulp; only two cases in NHA group (20%) demonstrated uninflamed normal pulp. CEM cement was superior to NHA as a DPC agent in terms of HTB formation and pulp inflammation scores. It is a suitable material for the DPC of primary teeth.

[Effect of GABA, sodium glutamate and glycine on evoked potentials in the dental zones of the cerebral cortex].

PubMed

Degtiarev, V P

1979-01-01

Intraventricular administration of gamma-aminobutyric acid (GABA) and glycine decreased, whereas sodium glutamate increased the amplitude of primary responses of dental zones of the somatosensory cortex, which arose during electric stimulation of the pulp of the rabbit upper incisors. No changes in the latent periods were recorded.

Differences of isolated dental stem cells dependent on donor age and consequences for autologous tooth replacement.

PubMed

Kellner, Manuela; Steindorff, Marina M; Strempel, Jürgen F; Winkel, Andreas; Kühnel, Mark P; Stiesch, Meike

2014-06-01

Autologous therapy via stem cell-based tissue regeneration is an aim to rebuild natural teeth. One option is the use of adult stem cells from the dental pulp (DPSCs), which have been shown to differentiate into several types of tissue in vitro and in vivo, especially into tooth-like structures. DPSCs are mainly isolated from the dental pulp of third molars routinely extracted for orthodontic reasons. Due to the extraction of third molars at various phases of life, DPSCs are isolated at different developmental stages of the tooth. The present study addressed the question whether DPSCs from patients of different ages were similar in their growth characteristics with respect to the stage of tooth development. Therefore DPSCs from third molars of 12-30 year-old patients were extracted, and growth characteristics, e.g. doubling time and maximal cell division potential were analysed. In addition, pulp and hard dental material weight were recorded. Irrespective of the age of patients almost all isolated cells reached 40-60 generations with no correlation between maximal cell division potential and patient age. Cells from patients <22 years showed a significantly faster doubling time than the cells from patients ≥22 years. The age of patients at the time of stem cell isolation is not a crucial factor concerning maximal cell division potential, but does have an impact on the doubling time. However, differences in individuals regarding growth characteristics were more pronounced than age-dependent differences. Copyright © 2014 Elsevier Ltd. All rights reserved.

Enhanced regeneration potential of mobilized dental pulp stem cells from immature teeth.

PubMed

Nakayama, H; Iohara, K; Hayashi, Y; Okuwa, Y; Kurita, K; Nakashima, M

2017-07-01

We have previously demonstrated that dental pulp stem cells (DPSCs) isolated from mature teeth by granulocyte colony-stimulating factor (G-CSF)-induced mobilization method can enhance angiogenesis/vasculogenesis and improve pulp regeneration when compared with colony-derived DPSCs. However, the efficacy of this method in immature teeth with root-formative stage has never been investigated. Therefore, the aim of this study was to examine the stemness, biological characteristics, and regeneration potential in mobilized DPSCs compared with colony-derived DPSCs from immature teeth. Mobilized DPSCs isolated from immature teeth were compared to colony-derived DPSCs using methods including flow cytometry, migration assays, mRNA expression of angiogenic/neurotrophic factor, and induced differentiation assays. They were also compared in trophic effects of the secretome. Regeneration potential was further compared in an ectopic tooth transplantation model. Mobilized DPSCs had higher migration ability and expressed more angiogenic/neurotrophic factors than DPSCs. The mobilized DPSC secretome produced a higher stimulatory effect on migration, immunomodulation, anti-apoptosis, endothelial differentiation, and neurite extension. In addition, vascularization and pulp regeneration potential were higher in mobilized DPSCs than in DPSCs. G-CSF-induced mobilization method enhances regeneration potential of colony-derived DPSCs from immature teeth. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Construction and in vitro test of a new electrode for dentin resistance measurement.

PubMed

Stein, Steffen; Gente, Michael

2013-10-01

It is necessary to reduce the tooth substance before treating a tooth with a dental crown. The preparation often requires reduction of the dentin. This results in a dentin wound and a thinner substance over the pulp, increases the risk of inflammation, and could result in necrosis of the pulp. To give the dentist information about the amount of dentin over the pulp during preparation, the Prepometer was developed. The function of this device is based on the measurement of the electric resistance of the tooth substance. The measuring behavior of the first-generation Prepometer is characterized by smaller values of electric resistance before reaching full contact of the measuring head to the dentin surface and the actual value RT. This measuring behavior can mislead inexperienced therapists with inaccurate values that suggest thinner dentin than the reality. In this study, a new electrode based on the technology of active guard drive was constructed to overcome this issue. The results show that improvement in the measuring behavior of the new electrode could be achieved, eliminating the earlier disadvantage of the Prepometer.

Management of 2 teeth diagnosed with dens invaginatus with regenerative endodontics and apexification in the same patient: a case report and review.

PubMed

Kumar, Harleen; Al-Ali, Muna; Parashos, Peter; Manton, David J

2014-05-01

This review and case report present the treatment of a 10-year-old boy with both permanent maxillary lateral incisors demonstrating Oehlers type II dens invaginatus and pulpal involvement. Treatment was complicated by dental anxiety, supraventricular tachycardia, immature tooth development, and facial cellulitis. An infected necrotic pulp of the permanent maxillary left lateral incisor was treated by apexification and endodontic treatment with mineral trioxide aggregate. The necrotic pulp of the permanent maxillary right lateral incisor was treated with canal debridement and dressing under general anesthesia. Periapical healing of both teeth occurred, with the right lateral incisor showing continued root growth, thickening of the dentinal root walls, and completed apex formation. This tooth responded normally to pulp testing. Twenty-eight months after initial treatment, the right lateral incisor displayed progressive sclerosis of the canal. This case demonstrates possible pulpal regeneration of an infected maxillary right lateral incisor with dens invaginatus and an immature apex after minimal canal debridement. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

A clinical assessment of the effects of 10% carbamide peroxide gel on human pulp tissue.

PubMed

Anderson, D G; Chiego, D J; Glickman, G N; McCauley, L K

1999-04-01

Bleaching vital teeth with 10% carbamide peroxide gel is a routine procedure in which there has been no evidence of associated permanent pulpal damage. Synthesis of the enzyme heme oxygenase-1 (HO-1) is increased after exposure of eukaryotic cells to conditions of oxidative stress (including H2O2) as a defense against the damaging effects of free radicals. Dental pulps were evaluated for HO-1 (aka Heat Shock Protein 32) presence in teeth treated with 10% carbamide peroxide. Seventeen intact first premolars scheduled for orthodontic extraction were bleached for 4 h immediately preceding extraction. Fourteen additional premolars from the same individuals were not bleached. All 31 teeth were extracted, fixed, demineralized, frozen, sectioned, and immunostained with anti-HO-1 antibody using a standard ABC protocol. There was no significant difference in the presence of HO-1 between total bleached versus total unbleached teeth using the Fisher's Exact Test (p < or = 0.05). However, the histological findings could be interpreted to suggest that coronal odontoblasts and endothelial cells in the underlying pulp proper may have the potential to respond to oxidative stress by increasing the synthesis of HO-1 (HSP32). This could represent a component of an initial defensive response by specific cells in strategic locations in the pulp that precedes classical inflammatory pathways.

An analysis of the timing and materials associated with pulp disease following restorative dental treatment.

PubMed

Yong, J B; Sivarajan, S; Abbott, P V

2018-05-19

To assess whether the timing of pulp disease after tooth restoration was associated with type of restorative dental material used, extent of the restoration, or tooth type. A comprehensive search and analysis of data using the Titanium Oral Health Management software program at The Oral Health Centre of Western Australia was performed to correlate procedural codes for teeth that had restorations placed and subsequently developed pulp disease requiring endodontic treatment or extraction from 1 st January 2009 to 31 st December 2013. Manual analysis of paper and/or electronic patient record cards was also performed. Data collected included restoration type, restored tooth surfaces, tooth type, and the dates of restoration and subsequent endodontic intervention or extraction. Of 330 teeth that met the inclusion criteria, 84 (26%) had composite resin restorations, 80 (24%) had amalgams, 119 (36%) had GICs and 47 (14%) had crowns. The average time between restoration and further intervention was 330 days with a range from 3 days to 1,775 days (approx. 5 years). Teeth restored with crowns or five-surface restorations were significantly more likely to require earlier intervention than other restorations. Premolar and anterior teeth were also more likely to require earlier intervention. Teeth that developed pulp disease requiring further intervention that were restored with crowns and five-surface GIC developed the disease sooner than teeth that were restored with amalgam or composite. In teeth with five surface restorations that developed pulp disease requiring further intervention, premolar and anterior teeth developed the pulp disease sooner than molars. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Cryopreserved Dental Pulp Tissues of Exfoliated Deciduous Teeth Is a Feasible Stem Cell Resource for Regenerative Medicine

PubMed Central

Yamaza, Haruyoshi; Akiyama, Kentaro; Hoshino, Yoshihiro; Song, Guangtai; Kukita, Toshio; Nonaka, Kazuaki; Shi, Songtao; Yamaza, Takayoshi

2012-01-01

Human exfoliated deciduous teeth have been considered to be a promising source for regenerative therapy because they contain unique postnatal stem cells from human exfoliated deciduous teeth (SHED) with self-renewal capacity, multipotency and immunomodulatory function. However preservation technique of deciduous teeth has not been developed. This study aimed to evaluate that cryopreserved dental pulp tissues of human exfoliated deciduous teeth is a retrievable and practical SHED source for cell-based therapy. SHED isolated from the cryopreserved deciduous pulp tissues for over 2 years (25–30 months) (SHED-Cryo) owned similar stem cell properties including clonogenicity, self-renew, stem cell marker expression, multipotency, in vivo tissue regenerative capacity and in vitro immunomodulatory function to SHED isolated from the fresh tissues (SHED-Fresh). To examine the therapeutic efficacy of SHED-Cryo on immune diseases, SHED-Cryo were intravenously transplanted into systemic lupus erythematosus (SLE) model MRL/lpr mice. Systemic SHED-Cryo-transplantation improved SLE-like disorders including short lifespan, elevated autoantibody levels and nephritis-like renal dysfunction. SHED-Cryo amended increased interleukin 17-secreting helper T cells in MRL/lpr mice systemically and locally. SHED-Cryo-transplantation was also able to recover osteoporosis bone reduction in long bones of MRL/lpr mice. Furthermore, SHED-Cryo-mediated tissue engineering induced bone regeneration in critical calvarial bone-defect sites of immunocompromised mice. The therapeutic efficacy of SHED-Cryo transplantation on immune and skeletal disorders was similar to that of SHED-Fresh. These data suggest that cryopreservation of dental pulp tissues of deciduous teeth provide a suitable and desirable approach for stem cell-based immune therapy and tissue engineering in regenerative medicine. PMID:23251621

Validation of Optical Coherence Tomography against Micro-computed Tomography for Evaluation of Remaining Coronal Dentin Thickness.

PubMed

Majkut, Patrycja; Sadr, Alireza; Shimada, Yasushi; Sumi, Yasunori; Tagami, Junji

2015-08-01

Optical coherence tomography (OCT) is a noninvasive modality to obtain in-depth images of biological structures. A dental OCT system has become available for chairside application. This in vitro study hypothesized that swept-source OCT can be used to measure the remaining dentin thickness (RDT) at the roof of the dental pulp chamber during excavation of deep caries. Human molar teeth with deep occlusal caries were investigated. After obtaining 2-dimensional and 3-dimensional OCT scans using a swept-source OCT system at a 1330-nm center wavelength, RDT was evaluated by image analysis software. Microfocus x-ray computed tomographic (micro-CT) images were obtained from the same cross sections to confirm OCT findings. The smallest RDT values at the visible pulp horn were measured on OCT and micro-CT imaging and compared using the Pearson correlation. Pulpal horns and pulp chamber roof observation under OCT and micro-CT imaging resulted in comparable images that allowed the measurement of coronal dentin thickness. RDT measured by OCT showed optical values range between 140 and 2300 μm, which corresponded to the range of 92-1524 μm on micro-CT imaging. A strong correlation was found between the 2 techniques (r = 0.96, P < .001). Further analysis indicated linear regression with a slope of 1.54 and no intercept, closely matching the bulk refractive index of dentin. OCT enables visualization of anatomic structures during deep caries excavation. Exposure of the vital dental pulp because of the removal of very thin remaining coronal dentin can be avoided with this novel noninvasive technique. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Evaluation of an experimental rat model for comparative studies of bleaching agents

PubMed Central

Cintra, Luciano Tavares Angelo; Benetti, Francine; Ferreira, Luciana Lousada; Rahal, Vanessa; Ervolino, Edilson; Jacinto, Rogério de Castilho; Gomes, João Eduardo; Briso, André Luiz Fraga

2016-01-01

ABSTRACT Dental materials, in general, are tested in different animal models prior to their clinical use in humans, except for bleaching agents. Objectives To evaluate an experimental rat model for comparative studies of bleaching agents by investigating the influence of different concentrations and application times of H2O2 gel in the pulp tissue during in-office bleaching of rats’ vital teeth. Material and methods The right and left maxillary molars of 50 Wistar rats were bleached with 20% and 35% H2O2 gels, respectively, for 5, 10, 15, 30, or 45 min (n=10 rats/group). Ten animals (control) were untreated. The rats were killed after 2 or 30 days, and the maxillae were examined by light microscopy. Inflammation was evaluated by histomorphometric analysis with inflammatory cell counting in the coronal and radicular thirds of the pulp. The counting of fibroblasts was also performed. Scores were attributed to the odontoblastic layer and to vascular changes. The tertiary dentin area and the pulp chamber central area were histomorphometrically measured. Data were compared by the analysis of variance and the Kruskal-Wallis test (p<0.05). Results After 2 days, the amount of inflammatory cells increased in the occlusal third of the coronal pulp until the time of 15 min for both concentrations of bleaching gels. In 30 and 45 min groups of each concentration, the number of inflammatory cells decreased along with the appearance of necrotic areas. After 30 days, a reduction in the pulp chamber central area and an enlargement of tertiary dentin area were observed without the detection of inflammation areas. Conclusion The rat model of extra coronal bleaching showed to be adequate for bleaching protocols studies, as it was possible to observe alterations in the pulp tissues and in the tooth structure caused by different concentrations and periods of application of bleaching agents. PMID:27008262

Evaluation of an experimental rat model for comparative studies of bleaching agents.

PubMed

Cintra, Luciano Tavares Angelo; Benetti, Francine; Ferreira, Luciana Lousada; Rahal, Vanessa; Ervolino, Edilson; Jacinto, Rogério de Castilho; Gomes Filho, João Eduardo; Briso, André Luiz Fraga

2016-01-01

Dental materials, in general, are tested in different animal models prior to their clinical use in humans, except for bleaching agents. To evaluate an experimental rat model for comparative studies of bleaching agents by investigating the influence of different concentrations and application times of H2O2 gel in the pulp tissue during in-office bleaching of rats' vital teeth. The right and left maxillary molars of 50 Wistar rats were bleached with 20% and 35% H2O2 gels, respectively, for 5, 10, 15, 30, or 45 min (n=10 rats/group). Ten animals (control) were untreated. The rats were killed after 2 or 30 days, and the maxillae were examined by light microscopy. Inflammation was evaluated by histomorphometric analysis with inflammatory cell counting in the coronal and radicular thirds of the pulp. The counting of fibroblasts was also performed. Scores were attributed to the odontoblastic layer and to vascular changes. The tertiary dentin area and the pulp chamber central area were histomorphometrically measured. Data were compared by the analysis of variance and the Kruskal-Wallis test (p<0.05). After 2 days, the amount of inflammatory cells increased in the occlusal third of the coronal pulp until the time of 15 min for both concentrations of bleaching gels. In 30 and 45 min groups of each concentration, the number of inflammatory cells decreased along with the appearance of necrotic areas. After 30 days, a reduction in the pulp chamber central area and an enlargement of tertiary dentin area were observed without the detection of inflammation areas. The rat model of extra coronal bleaching showed to be adequate for bleaching protocols studies, as it was possible to observe alterations in the pulp tissues and in the tooth structure caused by different concentrations and periods of application of bleaching agents.

Highly Efficient In Vitro Reparative Behaviour of Dental Pulp Stem Cells Cultured with Standardised Platelet Lysate Supplementation.

PubMed

Marrazzo, Pasquale; Paduano, Francesco; Palmieri, Francesca; Marrelli, Massimo; Tatullo, Marco

2016-01-01

Dental pulp is an accessible source of multipotent mesenchymal stromal cells (MSCs). The perspective role of dental pulp stem cells (DPSCs) in regenerative medicine demands an in vitro expansion and in vivo delivery which must deal with the safety issues about animal serum, usually required in cell culture practice. Human platelet lysate (PL) contains autologous growth factors and has been considered as valuable alternative to fetal bovine serum (FBS) in cell cultures. The optimum concentration to be added of such supplement is highly dependent on its preparation whose variability limits comparability of results. By in vitro experiments, we aimed to evaluate a standardised formulation of pooled PL. A low selected concentration of PL (1%) was able to support the growth and maintain the viability of the DPSCs. The use of PL in cell cultures did not impair cell surface signature typically expressed by MSCs and even upregulated the transcription of Sox2. Interestingly, DPSCs cultured in presence of PL exhibited a higher healing rate after injury and are less susceptible to toxicity mediated by exogenous H 2 O 2 than those cultured with FBS. Moreover, PL addition was shown as a suitable option for protocols promoting osteogenic and chondrogenic differentiation of DPSCs. Taken together, our results indicated that PL is a valid substitute of FBS to culture and differentiate DPSCs for clinical-grade use.

Highly Efficient In Vitro Reparative Behaviour of Dental Pulp Stem Cells Cultured with Standardised Platelet Lysate Supplementation

PubMed Central

Palmieri, Francesca; Marrelli, Massimo

2016-01-01

Dental pulp is an accessible source of multipotent mesenchymal stromal cells (MSCs). The perspective role of dental pulp stem cells (DPSCs) in regenerative medicine demands an in vitro expansion and in vivo delivery which must deal with the safety issues about animal serum, usually required in cell culture practice. Human platelet lysate (PL) contains autologous growth factors and has been considered as valuable alternative to fetal bovine serum (FBS) in cell cultures. The optimum concentration to be added of such supplement is highly dependent on its preparation whose variability limits comparability of results. By in vitro experiments, we aimed to evaluate a standardised formulation of pooled PL. A low selected concentration of PL (1%) was able to support the growth and maintain the viability of the DPSCs. The use of PL in cell cultures did not impair cell surface signature typically expressed by MSCs and even upregulated the transcription of Sox2. Interestingly, DPSCs cultured in presence of PL exhibited a higher healing rate after injury and are less susceptible to toxicity mediated by exogenous H2O2 than those cultured with FBS. Moreover, PL addition was shown as a suitable option for protocols promoting osteogenic and chondrogenic differentiation of DPSCs. Taken together, our results indicated that PL is a valid substitute of FBS to culture and differentiate DPSCs for clinical-grade use. PMID:27774106

Human Dental Pulp Cells Differentiate toward Neuronal Cells and Promote Neuroregeneration in Adult Organotypic Hippocampal Slices In Vitro.

PubMed

Xiao, Li; Ide, Ryoji; Saiki, Chikako; Kumazawa, Yasuo; Okamura, Hisashi

2017-08-11

The adult mammalian central nerve system has fundamental difficulties regarding effective neuroregeneration. The aim of this study is to investigate whether human dental pulp cells (DPCs) can promote neuroregeneration by (i) being differentiated toward neuronal cells and/or (ii) stimulating local neurogenesis in the adult hippocampus. Using immunostaining, we demonstrated that adult human dental pulp contains multipotent DPCs, including STRO-1, CD146 and P75-positive stem cells. DPC-formed spheroids were able to differentiate into neuronal, vascular, osteogenic and cartilaginous lineages under osteogenic induction. However, under neuronal inductive conditions, cells in the DPC-formed spheroids differentiated toward neuronal rather than other lineages. Electrophysiological study showed that these cells consistently exhibit the capacity to produce action potentials, suggesting that they have a functional feature in neuronal cells. We further co-cultivated DPCs with adult mouse hippocampal slices on matrigel in vitro. Immunostaining and presto blue assay showed that DPCs were able to stimulate the growth of neuronal cells (especially neurons) in both the CA1 zone and the edges of the hippocampal slices. Brain-derived neurotrophic factor (BDNF), was expressed in co-cultivated DPCs. In conclusion, our data demonstrated that DPCs are well-suited to differentiate into the neuronal lineage. They are able to stimulate neurogenesis in the adult mouse hippocampus through neurotrophic support in vitro.

In Vitro and In Vivo Dentinogenic Efficacy of Human Dental Pulp-Derived Cells Induced by Demineralized Dentin Matrix and HA-TCP

PubMed Central

Kang, Kyung-Jung; Lee, Min Suk; Moon, Chan-Woong; Lee, Jae-Hoon

2017-01-01

Human dental pulp cells have been known to have the stem cell features such as self-renewal and multipotency. These cells are differentiated into hard tissue by addition of proper cytokines and biomaterials. Hydroxyapatite-tricalcium phosphates (HA-TCPs) are essential components of hard tissue and generally used as a biocompatible material in tissue engineering of bone. Demineralized dentin matrix (DDM) has been reported to increase efficiency of bone induction. We compared the efficiencies of osteogenic differentiation and in vivo bone formation of HA-TCP and DDM on human dental pulp stem cells (hDPSCs). DDM contains inorganic components as with HA-TCP, and organic components such as collagen type-1. Due to these components, osteoinduction potential of DDM on hDPSCs was remarkably higher than that of HA-TCP. However, the efficiencies of in vivo bone formation are similar in HA-TCP and DDM. Although osteogenic gene expression and bone formation in immunocompromised nude mice were similar levels in both cases, dentinogenic gene expression level was slightly higher in DDM transplantation than in HA-TCP. All these results suggested that in vivo osteogenic potentials in hDPSCs are induced with both HA-TCP and DDM by osteoconduction and osteoinduction, respectively. In addition, transplantation of hDPSCs/DDM might be more effective for differentiation into dentin. PMID:28761445

Biological Characteristics of Fluorescent Superparamagnetic Iron Oxide Labeled Human Dental Pulp Stem Cells

PubMed Central

Li, Ming-wei; Bai, Yu; Guo, Hui-hui

2017-01-01

Tracking transplanted stem cells is necessary to clarify cellular properties and improve transplantation success. In this study, we investigate the effects of fluorescent superparamagnetic iron oxide particles (SPIO) (Molday ION Rhodamine-B™, MIRB) on biological properties of human dental pulp stem cells (hDPSCs) and monitor hDPSCs in vitro and in vivo using magnetic resonance imaging (MRI). Morphological analysis showed that intracellular MIRB particles were distributed in the cytoplasm surrounding the nuclei of hDPSCs. 12.5–100 μg/mL MIRB all resulted in 100% labeling efficiency. MTT showed that 12.5–50 μg/mL MIRB could promote cell proliferation and MIRB over 100 μg/mL exhibited toxic effect on hDPSCs. In vitro MRI showed that 1 × 106 cells labeled with various concentrations of MIRB (12.5–100 μg/mL) could be visualized. In vivo MRI showed that transplanted cells could be clearly visualized up to 60 days after transplantation. These results suggest that 12.5–50 μg/mL MIRB is a safe range for labeling hDPSCs. MIRB labeled hDPSCs cell can be visualized by MRI in vitro and in vivo. These data demonstrate that MIRB is a promising candidate for hDPSCs tracking in hDPSCs based dental pulp regeneration therapy. PMID:28298928

3D porous chitosan scaffolds suit survival and neural differentiation of dental pulp stem cells.

PubMed

Feng, Xingmei; Lu, Xiaohui; Huang, Dan; Xing, Jing; Feng, Guijuan; Jin, Guohua; Yi, Xin; Li, Liren; Lu, Yuanzhou; Nie, Dekang; Chen, Xiang; Zhang, Lei; Gu, Zhifeng; Zhang, Xinhua

2014-08-01

A key aspect of cell replacement therapy in brain injury treatment is construction of a suitable biomaterial scaffold that can effectively carry and transport the therapeutic cells to the target area. In the present study, we created small 3D porous chitosan scaffolds through freeze-drying, and showed that these can support and enhance the differentiation of dental pulp stem cells (DPSCs) to nerve cells in vitro. The DPSCs were collected from the dental pulp of adult human third molars. At a swelling rate of ~84.33 ± 10.92 %, the scaffold displayed high porosity and interconnectivity of pores, as revealed by SEM. Cell counting kit-8 assay established the biocompatibility of the chitosan scaffold, supporting the growth and survival of DPSCs. The successful neural differentiation of DPSCs was assayed by RT-PCR, western blotting, and immunofluorescence. We found that the scaffold-attached DPSCs showed high expression of Nestin that decreased sharply following induction of differentiation. Exposure to the differentiation media also increased the expression of neural molecular markers Microtubule-associated protein 2, glial fibrillary acidic protein, and 2',3'-cyclic nucleotide phosphodiesterase. This study demonstrates that the granular 3D chitosan scaffolds are non-cytotoxic, biocompatible, and provide a conducive and favorable micro-environment for attachment, survival, and neural differentiation of DPSCs. These scaffolds have enormous potential to facilitate future advances in treatment of brain injury.

Decellularized bone extracellular matrix and human dental pulp stem cells as a construct for bone regeneration.

PubMed

Paduano, Francesco; Marrelli, Massimo; Alom, Noura; Amer, Mahetab; White, Lisa J; Shakesheff, Kevin M; Tatullo, Marco

2017-06-01

Dental pulp tissue represents a source of mesenchymal stem cells that have a strong differentiation potential towards the osteogenic lineage. The objective of the current study was to examine in vitro osteogenic induction of dental pulp stem cells (DPSCs) cultured on hydrogel scaffolds derived from decellularized bone extracellular matrix (bECM) compared to collagen type I (Col-I), the major component of bone matrix. DPSCs in combination with bECM hydrogels were cultured under three different conditions: basal medium, osteogenic medium and medium supplemented with growth factors (GFs) and cell growth, mineral deposition, gene and protein expression were investigated. The DPSCs/bECM hydrogel constructs cultured in basal medium showed that cells were viable after three weeks and that the expression of runt-related transcription factor 2 (RUNX-2) and bone sialoprotein (BSP) were significantly upregulated in the absence of extra osteogenic inducers compared to Col-I hydrogel scaffolds. In addition, the protein expression levels of BSP and osteocalcin were higher on bECM with respect to Col-I hydrogel scaffolds. Furthermore, DPSCs/bECM hydrogels cultured with osteogenic or GFs supplemented medium displayed a higher upregulation of the osteo-specific markers compared to Col-I hydrogels in identical media. Collectively, our results demonstrate that bECM hydrogels might be considered as suitable scaffolds to support osteogenic differentiation of DPSCs.

In Vitro and In Vivo Dentinogenic Efficacy of Human Dental Pulp-Derived Cells Induced by Demineralized Dentin Matrix and HA-TCP.

PubMed

Kang, Kyung-Jung; Lee, Min Suk; Moon, Chan-Woong; Lee, Jae-Hoon; Yang, Hee Seok; Jang, Young-Joo

2017-01-01

Human dental pulp cells have been known to have the stem cell features such as self-renewal and multipotency. These cells are differentiated into hard tissue by addition of proper cytokines and biomaterials. Hydroxyapatite-tricalcium phosphates (HA-TCPs) are essential components of hard tissue and generally used as a biocompatible material in tissue engineering of bone. Demineralized dentin matrix (DDM) has been reported to increase efficiency of bone induction. We compared the efficiencies of osteogenic differentiation and in vivo bone formation of HA-TCP and DDM on human dental pulp stem cells (hDPSCs). DDM contains inorganic components as with HA-TCP, and organic components such as collagen type-1. Due to these components, osteoinduction potential of DDM on hDPSCs was remarkably higher than that of HA-TCP. However, the efficiencies of in vivo bone formation are similar in HA-TCP and DDM. Although osteogenic gene expression and bone formation in immunocompromised nude mice were similar levels in both cases, dentinogenic gene expression level was slightly higher in DDM transplantation than in HA-TCP. All these results suggested that in vivo osteogenic potentials in hDPSCs are induced with both HA-TCP and DDM by osteoconduction and osteoinduction, respectively. In addition, transplantation of hDPSCs/DDM might be more effective for differentiation into dentin.

Isolation of a stable subpopulation of mobilized dental pulp stem cells (MDPSCs) with high proliferation, migration, and regeneration potential is independent of age.

PubMed

Horibe, Hiroshi; Murakami, Masashi; Iohara, Koichiro; Hayashi, Yuki; Takeuchi, Norio; Takei, Yoshifumi; Kurita, Kenichi; Nakashima, Misako

2014-01-01

Insights into the understanding of the influence of the age of MSCs on their cellular responses and regenerative potential are critical for stem cell therapy in the clinic. We have isolated dental pulp stem cells (DPSCs) subsets based on their migratory response to granulocyte-colony stimulating factor (G-CSF) (MDPSCs) from young and aged donors. The aged MDPSCs were efficiently enriched in stem cells, expressing high levels of trophic factors with high proliferation, migration and anti-apoptotic effects compared to young MDPSCs. In contrast, significant differences in those properties were detected between aged and young colony-derived DPSCs. Unlike DPSCs, MDPSCs showed a small age-dependent increase in senescence-associated β-galactosidase (SA-β-gal) production and senescence markers including p16, p21, Interleukin (IL)-1β, -6, -8, and Groα in long-term culture. There was no difference between aged and young MDPSCs in telomerase activity. The regenerative potential of aged MDPSCs was similar to that of young MDPSCs in an ischemic hindlimb model and an ectopic tooth root model. These results demonstrated that the stem cell properties and the high regenerative potential of MDPSCs are independent of age, demonstrating an immense utility for clinical applications by autologous cell transplantation in dental pulp regeneration and ischemic diseases.

Human Dental Pulp Cells Differentiate toward Neuronal Cells and Promote Neuroregeneration in Adult Organotypic Hippocampal Slices In Vitro

PubMed Central

Ide, Ryoji; Saiki, Chikako; Kumazawa, Yasuo; Okamura, Hisashi

2017-01-01

The adult mammalian central nerve system has fundamental difficulties regarding effective neuroregeneration. The aim of this study is to investigate whether human dental pulp cells (DPCs) can promote neuroregeneration by (i) being differentiated toward neuronal cells and/or (ii) stimulating local neurogenesis in the adult hippocampus. Using immunostaining, we demonstrated that adult human dental pulp contains multipotent DPCs, including STRO-1, CD146 and P75-positive stem cells. DPC-formed spheroids were able to differentiate into neuronal, vascular, osteogenic and cartilaginous lineages under osteogenic induction. However, under neuronal inductive conditions, cells in the DPC-formed spheroids differentiated toward neuronal rather than other lineages. Electrophysiological study showed that these cells consistently exhibit the capacity to produce action potentials, suggesting that they have a functional feature in neuronal cells. We further co-cultivated DPCs with adult mouse hippocampal slices on matrigel in vitro. Immunostaining and presto blue assay showed that DPCs were able to stimulate the growth of neuronal cells (especially neurons) in both the CA1 zone and the edges of the hippocampal slices. Brain-derived neurotrophic factor (BDNF), was expressed in co-cultivated DPCs. In conclusion, our data demonstrated that DPCs are well-suited to differentiate into the neuronal lineage. They are able to stimulate neurogenesis in the adult mouse hippocampus through neurotrophic support in vitro. PMID:28800076

Dental Aspect of Distal Tubular Renal Acidosis with Genu Valgum Secondary to Rickets: A Case Report

PubMed Central

Bahadure, Rakesh N.; Thosar, Nilima; Kriplani, Ritika; Baliga, Sudhindra; Fulzele, Punit

2012-01-01

Distal renal tubular acidosis is a disease that occurs when the kidneys do not remove acid properly into the urine, leaving the blood too acidic (called acidosis). Distal renal tubular acidosis (type I RTA) is caused by a defect in the kidney tubes that causes acid to build up in the bloodstream. It ultimately results rickets which include chronic skeletal pain, in skeletal deformities, skeletal fractures. Rickets is among the most frequent childhood diseases in many developing countries. Dental problems in rickets include delayed eruption of permanent teeth, premature fall of deciduous teeth, defects in structure of teeth, enamel defects in permanent teeth (hypoplastic), pulp defects, intraglobular dentine, and caries tooth. Herewith, reported a case of distal tubular renal acidosis with genu valgum secondary to rickets, with pain and extraoral swelling associated with right and left mandibular 1st permanent molars. Teeth were infected with pulp without being involved with caries. Radiographically cracks in enamel and dentin were observed. Pulp revascularization with 46 and root canal treatment was done for 36 with followup of 1 year. PMID:22567455

Concentrations of and application protocols for hydrogen peroxide bleaching gels: effects on pulp cell viability and whitening efficacy.

PubMed

Soares, Diana Gabriela; Basso, Fernanda Gonçalves; Hebling, Josimeri; de Souza Costa, Carlos Alberto

2014-02-01

To assess the whitening effectiveness and the trans-enamel/trans-dentinal toxicity of experimental tooth-bleaching protocols on pulp cells. Enamel/dentine discs individually adapted to trans-well devices were placed on cultured odontoblast-like cells (MDPC-23) or human dental pulp cells (HDPCs). The following groups were formed: G1 - no treatment (control); G2 to G4 - 35% H2O2, 3 × 15, 1 × 15, and 1 × 5 min, respectively; and G5 to G7 - 17.5% H2O2, 3 × 15, 1 × 15, and 1 × 5 min, respectively. Cell viability and morphology were evaluated immediately after bleaching (T1) and 72 h thereafter (T2). Oxidative stress and cell membrane damage were also assessed (T1). The amount of H2O2 in culture medium was quantified (Mann-Whitney; α=5%) and colour change (ΔE) of enamel was analysed after 3 sessions (Tukey's test; α=5%). Cell viability reduction, H2O2 diffusion, cell morphology alteration, oxidative stress, and cell membrane damage occurred in a concentration-/time-dependent fashion. The cell viability reduction was significant in all groups for HDPCs and only for G2, G3, and G5 in MDPC-23 cells compared with G1. Significant cell viability and morphology recovery were observed in all groups at T2, except for G2 in HDPCs. The highest ΔE value was found in G2. However, all groups presented significant ΔE increases compared with G1. Shortening the contact time of a 35%-H2O2 gel for 5 min, or reducing its concentration to 17.5% and applying it for 45, 15, or 5 min produce gradual tooth colour change associated with reduced trans-enamel and trans-dentinal cytotoxicity to pulp cells. The experimental protocols tested in the present study provided significant tooth-bleaching improvement associated with decreased toxicity to pulp cells, which may be an interesting alternative to be tested in clinical situations intended to reduce tooth sensitivity and pulp damage. Copyright © 2013 Elsevier Ltd. All rights reserved.

PAR-1 and PAR-2 Expression Is Enhanced in Inflamed Odontoblast Cells.

PubMed

Alvarez, M M P; Moura, G E; Machado, M F M; Viana, G M; de Souza Costa, C A; Tjäderhane, L; Nader, H B; Tersariol, I L S; Nascimento, F D

2017-12-01

Protease-activated receptors (PARs) are G protein-coupled receptors, which are activated by proteolytical cleavage of the amino-terminus and act as sensors for extracellular proteases. We hypothesized that PAR-1 and PAR-2 can be modulated by inflammatory stimulus in human dental pulp cells. PAR-1 and PAR-2 gene expression in human pulp tissue and MDPC-23 cells were analyzed by quantitative polymerase chain reaction. Monoclonal PAR-1 and PAR-2 antibodies were used to investigate the cellular expression of these receptors using Western blot, flow cytometry, and confocal microscopy in MDPC-23 cells. Immunofluorescence assays of human intact and carious teeth were performed to assess the presence of PAR-1 and PAR-2 in the dentin-pulp complex. The results show for the first time that human odontoblasts and MDPC-23 cells constitutively express PAR-1 and PAR-2. PAR-2 activation increased significantly the messenger RNA expression of matrix metalloproteinase (MMP)-2, MMP-9, MMP-13, and MMP-14 in MDPC-23 cells ( P < 0.05), while the expression of these enzymes decreased significantly in the PAR-1 agonist group ( P < 0.05). The high-performance liquid chromatography and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry analysis showed the presence of MMP-13 activity cleaving PAR-1 at specific, noncanonical site TLDPRS 42 ↓F 43 LL in human dental pulp tissues. Also, we detected a presence of a trypsin-like activity cleaving PAR-2 at canonical site SKGR 20 ↓S 21 LIGRL in pulp tissues. Confocal microscopy analysis of human dentin-pulp complex showed intense positive staining of PAR-1 and PAR-2 in the odontoblast processes in dentinal tubules of carious teeth compared to intact ones. The present results support the hypothesis of activation of the upregulated PAR-1 and PAR-2 by endogenous proteases abundant during the inflammatory response in dentin-pulp complex.

Clinical and histological evaluation of thermal injury thresholds in human teeth: a preliminary study.

PubMed

Baldissara, P; Catapano, S; Scotti, R

1997-11-01

The effect on healthy dental pulp of thermal increases ranging from 8.9 to 14.7 degrees C was evaluated. These temperature increases correspond approximately to those caused by certain restorative procedures, such as tooth preparation with high-speed instruments and the fabrication of direct provisional crowns. Two criteria of evaluation have been used in conjunction, a clinical (symptomatic) and a histological one, to assert with greater precision potential damage to the pulp. The results suggest a low susceptibility of cells to heat, which does not appear to be a major factor of injury, at least in the short term. The main cause of postoperative inflammation or necrosis of the pulp is probably the injury of the dentine, a tissue in direct functional and physiological connection with the pulp.

Effect of the CO2 laser (9.6μm) on the dental pulp in humans

NASA Astrophysics Data System (ADS)

Wigdor, Harvey A.; Walsh, Joseph T., Jr.; Mostafi, Reza

2000-03-01

There has been great interest in the potential use of a laser to replace the dental handpiece (drill). Ideally a laser emitting radiation that is absorbed strongly by both the water and hydroxyapatite in teeth, would be a more efficient laser. Previous investigators showed that the 9.3 and 9.6 micron wavelength bands of the CO2 laser contain hydroxyapatite absorption peaks. For this study, human patients who were to have teeth removed for either orthodontic or periodontal reasons were used. A total of 16 teeth were irradiated. The number of teeth treated per patient varied from 1 - 4. The laser used was a prototype CO2 laser (ESC Medical Systems, Yokneam, Israel). The CO2 laser emits 50 mJ 60 microsecond-long pulses of 9.6 micrometer radiation in a beam focused to a 300 micrometer diameter (i/e2) spot. The pulps in both the laser and handpiece prepared holes appeared similar and had no apparent inflammation or vascular changes. It appears from this small sample of laser treated human teeth that this laser has an equal effect to the dental pulpal tissue when compared to the dental handpiece.

Stimulation of interleukin-1beta-independent interleukin-6 production in human dental pulp cells by lipopolysaccharide.

PubMed

Hosoya, S; Matsushima, K; Ohbayashi, E; Yamazaki, M; Shibata, Y; Abiko, Y

1996-12-01

Dental pulpal infection is most commonly caused by extensive dental caries. A principal driving force behind pulpal disease response appears to lie in the immune system's response to bacteria. However, the production of interleukin (IL)-1beta and IL-6 in human dental pulp (HDP) cells in response to lipopolysaccharide (LPS) has not been well characterized. We examined IL-1beta and IL-6 production in HDP cells by challenging with LPS from Porphyromonas endodontalis, which is a Gram-negative bacteria found in root canals. Our results presented here showed that when HDP cells were stimulated by LPS, the production of IL-6 always preceded that of IL-1beta. Since the IL-6 production was observed even in the presence of the IL-1beta receptor antagonist, we concluded IL-6 production was independent of the IL-1beta molecule in LPS-stimulated HDP cells. This idea was further supported by the results obtained from RT-PCR experiments, in which IL-6 mRNA, but not IL-1beta mRNA, was present in the RNA preparation isolated from the early stage of cells.

Pulp-dentin biology in restorative dentistry. Part 1: normal structure and physiology.

PubMed

Mjör, I A; Sveen, O B; Heyeraas, K J

2001-06-01

Considerable knowledge has accumulated over the years on the structure and function of the dental pulp and dentin. Some of this knowledge has important clinical implications. This review, which is the first of seven articles, will be limited to those parts of the normal structure and physiology of the pulp and dentin that have been shown to result in, or are likely lead to, tissue reactions associated with the clinical treatment of these tissues. Although certain normal structures will be highlighted in some detail, a basic knowledge of pulpal and dentinal development and structure is a prerequisite for an understanding of this text.

Role of laser irradiation in direct pulp capping procedures: a systematic review and meta-analysis.

PubMed

Javed, Fawad; Kellesarian, Sergio Varela; Abduljabbar, Tariq; Gholamiazizi, Elham; Feng, Changyong; Aldosary, Khaled; Vohra, Fahim; Romanos, Georgios E

2017-02-01

A variety of materials are available to treat exposed dental pulp by direct pulp capping. The healing response of the pulp is crucial to form a dentin bridge and seal off the exposed pulp. Studies have used lasers to stimulate the exposed pulp to form tertiary dentin. The aim of the present systematic review and meta-analysis was to evaluate the evidence on the effects of laser irradiation as an adjunctive therapy to stimulate healing after pulp exposure. A systematic literature search was conducted up to April 2016. A structured search using the keywords "Direct pulp capping," "Lasers," "Calcium hydroxide pulp capping," and "Resin pulp capping" was performed. Initially, 34 potentially relevant articles were identified. After removal of duplicates and screening by title, abstract, and full text when necessary, nine studies were included. Studies were assessed for bias and data were synthetized using a random-effects meta-analysis model. Six studies were clinical, and three were preclinical animal trials; the follow-up period ranged from 2 weeks to 54 months. More than two thirds of the included studies showed that laser therapy used as an adjunct for direct pulp capping was more effective in maintaining pulp vitality than conventional therapy alone. Meta-analysis showed that the success rate in the laser treatment group was significantly higher than the control group (log odds ratio = 1.737; 95 % confidence interval, 1.304-2.171). Lasers treatment of exposed pulps can improve the outcome of direct pulp capping procedures; a number of confounding factors may have influenced the outcomes of the included studies.

IN VITRO STUDY OF THE PULP CHAMBER TEMPERATURE RISE DURING LIGHT-ACTIVATED BLEACHING

PubMed Central

Carrasco, Thaise Graciele; Carrasco-Guerisoli, Laise Daniela; Fröner, Izabel Cristina

2008-01-01

This study evaluated in vitro the pulp chamber temperature rise induced by the light-activated dental bleaching technique using different light sources. The root portions of 78 extracted sound human mandibular incisors were sectioned approximately 2 mm below the cementoenamel junction. The root cavities of the crowns were enlarged to facilitate the correct placing of the sensor into the pulp chamber. Half of specimens (n=39) was assigned to receive a 35% hydrogen peroxide gel on the buccal surface and the other halt (n=39) not to receive the bleaching agent. Three groups (n=13) were formed for each condition (bleach or no bleach) according to the use of 3 light sources recommended for dental bleaching: a light-emitting diode (LED)-laser system, a LED unit and a conventional halogen light. The light sources were positioned perpendicular to the buccal surface at a distance of 5 mm and activated during 30 s. The differences between the initial and the highest temperature readings for each specimen were obtained, and, from the temperature changes, the means for each specimen and each group were calculated. The values of temperature rise were compared using Kruskal-Wallis test at 1% significance level. Temperature rise varied significantly depending on the light-curing unit, with statistically significant differences (p<0.01) among the groups. When the bleaching agent was not applied, the halogen light induced the highest temperature rise (2.38±0.66°C). The LED unit produced the lowest temperature increase (0.29±0.13°C); but there was no significant difference between LED unit and LED-laser system (0.35±0.15°C) (p>0.01). When the bleaching agent was applied, there were significant differences among groups (p<0.01): halogen light induced the highest temperature rise (1.41±0.64°C), and LED-laser system the lowest (0.33±0.12°C); however, there was no difference between LED-laser system and LED unit (0.44±0.11°C). LED and LED-laser system did not differ significantly from each other regardless the temperature rise occurred with or without bleaching agent application. It may be concluded that during light-activated tooth bleaching, with or without the bleaching agent, halogen light promoted higher pulp chamber temperature rise than LED unit and LED-laser system. The tested light-curing units provided increases in the pulp chamber temperature that were compatible with pulpal health. PMID:19089234

Colorimeter and scanning electron microscopy analysis of teeth submitted to internal bleaching.

PubMed

Martin-Biedma, Benjamin; Gonzalez-Gonzalez, Teresa; Lopes, Manuela; Lopes, Luis; Vilar, Rui; Bahillo, José; Varela-Patiño, Purificación

2010-02-01

This in vitro study compared the tooth color and the ultrastructure of internal dental tissues before and after internal bleaching. Sodium perborate was placed in the pulp chamber of endodontically treated molars and sealed with intermediate restorative material. The test samples were stored in a physiologic solution, and the bleaching agent was replaced every 7 days. A control group was used. After 1 month, the colors of the test and control samples were measured with a colorimeter, and the internal surfaces were observed under field emission scanning electron microscopy (FESEM). Statistically significant differences were found between the test and control sample colors. The FESEM ultrastructure analysis of the internal enamel and dentin surfaces did not show any changes after the internal bleaching. The results of the present study show that sodium perborate is effective in bleaching nonvital teeth and does not produce ultrastructural changes in the dental tissues. Copyright 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Biocompatibility and bioactivity of calcium silicate-based endodontic sealers in human dental pulp cells.

PubMed

Mestieri, Leticia Boldrin; Gomes-Cornélio, Ana Lívia; Rodrigues, Elisandra Márcia; Salles, Loise Pedrosa; Bosso-Martelo, Roberta; Guerreiro-Tanomaru, Juliane Maria; Tanomaru-Filho, Mário

2015-10-01

Mineral Trioxide Aggregate (MTA) is a calcium silicate-based material. New sealers have been developed based on calcium silicate as MTA Fillapex and MTA Plus. The aim of this study was to evaluate biocompatibility and bioactivity of these two calcium silicate-based sealers in culture of human dental pulp cells (hDPCs). The cells were isolated from third molars extracted from a 16-year-old patient. Pulp tissue was sectioned into fragments with approximately 1 mm3 and kept in supplemented medium to obtain hDPCs adherent cultures. Cell characterization assays were performed to prove the osteogenic potential. The evaluated materials were: MTA Plus (MTAP); MTA Fillapex (MTAF) and FillCanal (FC). Biocompatibility was evaluated with MTT and Neutral Red (NR) assays, after hDPCs exposure for 24 h to different dilutions of each sealer extract (1:2, 1:3 and 1:4). Unexposed cells were the positive control (CT). Bioactivity was assessed by alkaline phosphatase (ALP) enzymatic assay in cells exposed for one and three days to sealer extracts (1:4 dilution). All data were analyzed by ANOVA and Tukey post-test (p≤0.05%). MTT and NR results showed suitable cell viability rates for MTAP at all dilutions (90-135%). Cells exposed to MTAF and FC (1:2 and 1:4 dilutions) showed significant low viability rate when compared to CT in MTT. The NR results demonstrated cell viability for all materials tested. In MTAP group, the cells ALP activity was similar to CT in one and three days of exposure to the material. MTAF and FC groups demonstrated a decrease in ALP activity when compared to CT at both periods of cell exposure. The hDPCs were suitable for the evaluation of new endodontic materialsin vitro. MTAP may be considered a promising material for endodontic treatments.

Small Molecules Affect Human Dental Pulp Stem Cell Properties Via Multiple Signaling Pathways

PubMed Central

Al-Habib, Mey; Yu, Zongdong

2013-01-01

One fundamental issue regarding stem cells for regenerative medicine is the maintenance of stem cell stemness. The purpose of the study was to test whether small molecules can enhance stem cell properties of mesenchymal stem cells (MSCs) derived from human dental pulp (hDPSCs), which have potential for multiple clinical applications. We identified the effects of small molecules (Pluripotin (SC1), 6-bromoindirubin-3-oxime and rapamycin) on the maintenance of hDPSC properties in vitro and the mechanisms involved in exerting the effects. Primary cultures of hDPSCs were exposed to optimal concentrations of these small molecules. Treated hDPSCs were analyzed for their proliferation, the expression levels of pluripotent and MSC markers, differentiation capacities, and intracellular signaling activations. We found that small molecule treatments decreased cell proliferation and increased the expression of STRO-1, NANOG, OCT4, and SOX2, while diminishing cell differentiation into odonto/osteogenic, adipogenic, and neurogenic lineages in vitro. These effects involved Ras-GAP-, ERK1/2-, and mTOR-signaling pathways, which may preserve the cell self-renewal capacity, while suppressing differentiation. We conclude that small molecules appear to enhance the immature state of hDPSCs in culture, which may be used as a strategy for adult stem cell maintenance and extend their capacity for regenerative applications. PMID:23573877

The HOX genes are expressed, in vivo, in human tooth germs: in vitro cAMP exposure of dental pulp cells results in parallel HOX network activation and neuronal differentiation.

PubMed

D'Antò, Vincenzo; Cantile, Monica; D'Armiento, Maria; Schiavo, Giulia; Spagnuolo, Gianrico; Terracciano, Luigi; Vecchione, Raffaela; Cillo, Clemente

2006-03-01

Homeobox-containing genes play a crucial role in odontogenesis. After the detection of Dlx and Msx genes in overlapping domains along maxillary and mandibular processes, a homeobox odontogenic code has been proposed to explain the interaction between different homeobox genes during dental lamina patterning. No role has so far been assigned to the Hox gene network in the homeobox odontogenic code due to studies on specific Hox genes and evolutionary considerations. Despite its involvement in early patterning during embryonal development, the HOX gene network, the most repeat-poor regions of the human genome, controls the phenotype identity of adult eukaryotic cells. Here, according to our results, the HOX gene network appears to be active in human tooth germs between 18 and 24 weeks of development. The immunohistochemical localization of specific HOX proteins mostly concerns the epithelial tooth germ compartment. Furthermore, only a few genes of the network are active in embryonal retromolar tissues, as well as in ectomesenchymal dental pulp cells (DPC) grown in vitro from adult human molar. Exposure of DPCs to cAMP induces the expression of from three to nine total HOX genes of the network in parallel with phenotype modifications with traits of neuronal differentiation. Our observations suggest that: (i) by combining its component genes, the HOX gene network determines the phenotype identity of epithelial and ectomesenchymal cells interacting in the generation of human tooth germ; (ii) cAMP treatment activates the HOX network and induces, in parallel, a neuronal-like phenotype in human primary ectomesenchymal dental pulp cells. 2005 Wiley-Liss, Inc.

Autophagy in SDF-1α-mediated DPSC migration and pulp regeneration.

PubMed

Yang, Jing-Wen; Zhang, Yu-Feng; Wan, Chun-Yan; Sun, Zhe-Yi; Nie, Shuai; Jian, Shu-Juan; Zhang, Lu; Song, Guang-Tai; Chen, Zhi

2015-03-01

Critical morphological requirements for pulp regeneration are tissues replete with vascularisation, neuron formation, and dentin deposition. Autophagy was recently shown to be related to angiogenesis, neural differentiation, and osteogenesis. The present study aimed to investigate the involvement of autophagy in stromal cell-derived factor-1α (SDF-1α)-mediated dental pulp stem cell (DPSC) migration and pulp regeneration, and identify its presence during pulp revascularisation of pulpectomised dog teeth with complete apical closure. In vitro studies showed that SDF-1α enhanced DPSCs migration and optimised focal adhesion formation and stress fibre assembly, which were accompanied by autophagy. Moreover, autophagy inhibitors significantly suppressed, whereas autophagy activator substantially augmented SDF-1α-stimulated DPSCs migration. Furthermore, after ectopic transplantation of tooth fragment/silk fibroin scaffold with DPSCs into nude mice, pulp-like tissues with vascularity, well-organised fibrous matrix formation, and new dentin deposition along the dentinal wall were generated in SDF-1α-loaded samples accompanied by autophagy. More importantly, in a pulp revascularisation model in situ, SDF-1α-loaded silk fibroin scaffolds improved the de novo ingrowth of pulp-like tissues in pulpectomised mature dog teeth, which correlated with the punctuated LC3 and Atg5 expressions, indicating autophagy. Our findings provide novel insights into the pulp regeneration mechanism, and SDF-1α shows promise for future clinical application in pulp revascularisation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Histologic evaluation of human pulp tissue after orthodontic intrusion.

PubMed

Lazzaretti, Dieison Nardi; Bortoluzzi, Gianna Steffens; Torres Fernandes, Lauren Fioreze; Rodriguez, Rubens; Grehs, Renésio Armindo; Martins Hartmann, Mateus Silveira

2014-10-01

The forces applied during orthodontic treatment bring about effects on the teeth and surrounding tissues. The aim of this study was to evaluate the possible changes in the human pulpal tissue resulting from orthodontic intrusion in a 21-day period using histologic examination. The sample consisted of 17 young individuals of both sexes between the ages of 12 and 19 years. A total of 34 premolars were evaluated with orthodontic indication of extraction. Because it is a split-mouth study, in each patient, intrusion force of 60 g was applied randomly on 1 of the dental elements experimental group for 21 days. The counterpart control group received no force. After extractions, these dental elements were fixed in 10% formaldehyde, processed automatically, submitted to histotechnical preparation, and stained with hematoxylin-eosin for analysis under optical microscope. The paired Fisher exact test (P ≤ .05) showed a significant increase of fibrous tissue in the experimental group. The nonparametric paired Wilcoxon test (P ≤ .05) showed a significant increase in the number of pulpal nodules in the elements of the experimental group and showed no difference in the number of blood vessels between the groups. Large-caliber vessels and congested elements were observed in 8 of the experimental group elements. The orthodontic intrusion force, in these conditions, caused vascular changes in the pulpal tissue and also increased the presence of fibrosis and the number of pulp calcifications in the experimental elements. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Priming Dental Pulp Stem Cells With Fibroblast Growth Factor-2 Increases Angiogenesis of Implanted Tissue-Engineered Constructs Through Hepatocyte Growth Factor and Vascular Endothelial Growth Factor Secretion

PubMed Central

Gorin, Caroline; Rochefort, Gael Y.; Bascetin, Rumeyza; Ying, Hanru; Lesieur, Julie; Sadoine, Jérémy; Beckouche, Nathan; Berndt, Sarah; Novais, Anita; Lesage, Matthieu; Hosten, Benoit; Vercellino, Laetitia; Merlet, Pascal; Le-Denmat, Dominique; Marchiol, Carmen; Letourneur, Didier; Nicoletti, Antonino; Vital, Sibylle Opsahl; Poliard, Anne; Salmon, Benjamin; Germain, Stéphane

2016-01-01

Tissue engineering strategies based on implanting cellularized biomaterials are promising therapeutic approaches for the reconstruction of large tissue defects. A major hurdle for the reliable establishment of such therapeutic approaches is the lack of rapid blood perfusion of the tissue construct to provide oxygen and nutrients. Numerous sources of mesenchymal stem cells (MSCs) displaying angiogenic potential have been characterized in the past years, including the adult dental pulp. Establishment of efficient strategies for improving angiogenesis in tissue constructs is nevertheless still an important challenge. Hypoxia was proposed as a priming treatment owing to its capacity to enhance the angiogenic potential of stem cells through vascular endothelial growth factor (VEGF) release. The present study aimed to characterize additional key factors regulating the angiogenic capacity of such MSCs, namely, dental pulp stem cells derived from deciduous teeth (SHED). We identified fibroblast growth factor-2 (FGF-2) as a potent inducer of the release of VEGF and hepatocyte growth factor (HGF) by SHED. We found that FGF-2 limited hypoxia-induced downregulation of HGF release. Using three-dimensional culture models of angiogenesis, we demonstrated that VEGF and HGF were both responsible for the high angiogenic potential of SHED through direct targeting of endothelial cells. In addition, FGF-2 treatment increased the fraction of Stro-1+/CD146+ progenitor cells. We then applied in vitro FGF-2 priming to SHED before encapsulation in hydrogels and in vivo subcutaneous implantation. Our results showed that FGF-2 priming is more efficient than hypoxia at increasing SHED-induced vascularization compared with nonprimed controls. Altogether, these data demonstrate that FGF-2 priming enhances the angiogenic potential of SHED through the secretion of both HGF and VEGF. Significance The results from the present study show that fibroblast growth factor-2 (FGF-2) priming is more efficient than hypoxia at increasing dental pulp stem cells derived from deciduous teeth (SHED)-induced vascularization compared with nonprimed controls. Together, these data demonstrate that FGF-2 priming enhances the angiogenic potential of SHED through the secretion of both hepatocyte growth factor and vascular endothelial growth factor. PMID:26798059

In vivo stem cell transplantation using reduced cell numbers.

PubMed

Tsutsui, Takeo W

2015-01-01

Dental pulp stem cell (DPSC) characterization is essential for regeneration of a dentin/pulp like complex in vivo. This is especially important for identifying the potential of DPSCs to function as stem cells. Previously reported DPSC transplantation methods have used with huge numbers of cells, along with hydroxyapatite/tricalcium phosphate (HA/TCP), gelatin and fibrin, and collagen scaffolds. This protocol describe a transplantation protocol that uses fewer cells and a temperature-responsive cell culture dish.

An Insight Into Neurophysiology of Pulpal Pain: Facts and Hypotheses

PubMed Central

Gupta, Abhishek; N., Meena

2013-01-01

Pain and pain control are important to the dental profession because the general perception of the public is that dental treatment and pain go hand in hand. Successful dental treatment requires that the source of pain be detected. If the origin of pain is not found, inappropriate dental care and, ultimately, extraction may result. Pain experienced before, during, or after endodontic therapy is a serious concern to both patients and endodontists, and the variability of discomfort presents a challenge in terms of diagnostic methods, endodontic therapy, and endodontic knowledge. This review will help clinicians understand the basic neurophysiology of pulpal pain and other painful conditions of the dental pulp that are not well understood. PMID:24156000

An insight into neurophysiology of pulpal pain: facts and hypotheses.

PubMed

Jain, Niharika; Gupta, Abhishek; N, Meena

2013-10-01

Pain and pain control are important to the dental profession because the general perception of the public is that dental treatment and pain go hand in hand. Successful dental treatment requires that the source of pain be detected. If the origin of pain is not found, inappropriate dental care and, ultimately, extraction may result. Pain experienced before, during, or after endodontic therapy is a serious concern to both patients and endodontists, and the variability of discomfort presents a challenge in terms of diagnostic methods, endodontic therapy, and endodontic knowledge. This review will help clinicians understand the basic neurophysiology of pulpal pain and other painful conditions of the dental pulp that are not well understood.

Biomodulatory effects of laser irradiation on dental pulp cells in vitro

NASA Astrophysics Data System (ADS)

Milward, Michael R.; Hadis, Mohammed A.; Cooper, Paul R.; Gorecki, Patricia; Carroll, James D.; Palin, William M.

2015-03-01

Low level laser/light therapy (LLLT) or photobiomodulation is a biophysical approach that can be used to reduce pain, inflammation and modulate tissue healing and repair. However, its application has yet to be fully realized for dental disease treatment. The aim of this study was to assess the modulation of dental pulp cell (DPC) responses using two LLLT lasers with wavelengths of 660nm and 810nm. Human DPCs were isolated and cultured in phenol-red-free α- MEM/10%-FCS at 37°C in 5% CO2. Central wells of transparent-based black walled 96-microplates were seeded with DPCs (passages 2-4; 150μL; 25,000 cell/ml). At 24h post-seeding, cultures were irradiated using a Thor Photomedicine LLLT device (THOR Photomedicine, UK) at 660nm (3, 6 or 13s to give 2, 5 and 10J/cm2) or 810nm (for 1, 2 or 5s to deliver 5, 10 and 20J/cm2). Metabolic activity was assessed via a modified MTT assay 24h post-irradiation. Statistical differences were identified using analysis of variance and post-hoc Tukey tests (P=0.05) and compared with nonirradiated controls. Significantly higher MTT activity was obtained for both lasers (P<0.05) using the high and intermediate radiant exposure (5-20J/cm2). The MTT response significantly decreased (P<0.05) at lower radiant exposures with no statistical significance from control (P>0.05). Consequently, enhanced irradiation parameters was apparent for both lasers. These parameters should be further optimised to identify the most effective for therapeutic application.

Promotive Effect of Zinc Ions on the Vitality, Migration, and Osteogenic Differentiation of Human Dental Pulp Cells.

PubMed

An, Shaofeng; Gong, Qimei; Huang, Yihua

2017-01-01

Zinc is an essential trace element for proper cellular function and bone formation. However, its exact role in the osteogenic differentiation of human dental pulp cells (hDPCs) has not been fully clarified before. Here, we speculated that zinc may be effective to regulate their growth and osteogenic differentiation properties. To test this hypothesis, different concentrations (1 × 10 -5 , 4 × 10 -5 , and 8 × 10 -5  M) of zinc ions (Zn 2+ ) were added to the basic growth culture medium and osteogenic inductive medium. Cell viability and migration were measured by cell counting kit-8 (CCK-8) and transwell migration assay in the basic growth culture medium, respectively. The reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to detect the gene expression levels of selective osteogenic differentiation markers and zinc transporters. Alkaline phosphatase (ALP) activity analysis and alizarin red S staining were used to investigate the mineralization of hDPCs. Exposure of hDPCs to Zn 2+ stimulated their viability and migration capacity in a dose- and time-dependent manner. RT-qPCR assay revealed elevated expression levels of osteogenic differentiation-related genes and zinc transporters genes in various degrees. ALP activity was also increased with elevated Zn 2+ concentrations and extended culture periods, but enhanced matrix nodules formation were observed only in 4 × 10 -5 and 8 × 10 -5  M Zn 2+ groups. These findings suggest that specific concentrations of Zn 2+ could potentiate the vitality, migration, and osteogenic differentiation of hDPCs. We may combine optimum zinc element into pulp capping materials to improve their biological performance.

Regenerative endodontics--Creating new horizons.

PubMed

Dhillon, Harnoor; Kaushik, Mamta; Sharma, Roshni

2016-05-01

Trauma to the dental pulp, physical or microbiologic, can lead to inflammation of the pulp followed by necrosis. The current treatment modality for such cases is non-surgical root canal treatment. The damaged tissue is extirpated and the root canal system prepared. It is then obturated with an inert material such a gutta percha. In spite of advances in techniques and materials, 10%-15% of the cases may end in failure of treatment. Regenerative endodontics combines principles of endodontics, cell biology, and tissue engineering to provide an ideal treatment for inflamed and necrotic pulp. It utilizes mesenchymal stem cells, growth factors, and organ tissue culture to provide treatment. Potential treatment modalities include induction of blood clot for pulp revascularization, scaffold aided regeneration, and pulp implantation. Although in its infancy, successful treatment of damaged pulp tissue has been performed using principles of regenerative endodontics. This field is dynamic and exciting with the ability to shape the future of endodontics. This article highlights the fundamental concepts, protocol for treatment, and possible avenues for research in regenerative endodontics. © 2015 Wiley Periodicals, Inc.

The Microbial Challenge to Pulp Regeneration

PubMed Central

Fouad, A.F.

2011-01-01

Pulp regeneration is considered in cases where the dental pulp has been destroyed because of microbial irritation. Diverse oral and food-borne micro-organisms are able to invade the pulp space, form biofilm on canal walls, and infiltrate dentinal tubules. Prior to pulp regeneration procedures, the pulp space and dentinal walls need to be sufficiently disinfected to allow for and promote regeneration. The necessary level of disinfection is likely higher than that accepted for traditional endodontic therapy, because in traditional techniques the mere lowering of bacterial loads and prevention of bacterial access to periapical tissues is conducive to healing. Moreover, several of the non-specific antimicrobials used in traditional endodontic therapy may cause significant changes in remaining dentin that interfere with its inherent potential to mediate regeneration. Non-specific antimicrobials also suppress all microbial taxa, which may allow residual virulent micro-organisms to preferentially repopulate the pulp space. Therefore, it is important for endodontic pathogens to be studied by molecular methods that allow for a broad depth of coverage. It is then essential to determine the most effective protocols to disinfect the pulp space, with minimal disruption of remaining dentin. These protocols include the topical use of effective antibiotics, including newer agents that have demonstrated efficacy against endodontic pathogens. PMID:21677080

Optothermal transfer simulation in laser-irradiated human dentin.

PubMed

Moriyama, Eduardo H; Zangaro, Renato A; Lobo, Paulo D C; Villaverde, Antonio Balbin; Pacheco, Marcos T; Watanabe, Ii-Sei; Vitkin, Alex

2003-04-01

Laser technology has been studied as a potential replacement to the conventional dental drill. However, to prevent pulpal cell damage, information related to the safety parameters using high-power lasers in oral mineralized tissues is needed. In this study, the heat distribution profiles at the surface and subsurface regions of human dentine samples irradiated with a Nd:YAG laser were simulated using Crank-Nicolson's finite difference method for different laser energies and pulse durations. Heat distribution throughout the dentin layer, from the external dentin surface to the pulp chamber wall, were calculated in each case, to investigate the details of pulsed laser-hard dental tissue interactions. The results showed that the final temperature at the pulp chamber wall and at the dentin surface are strongly dependent on the pulse duration, exposure time, and the energy contained in each pulse.

Challenges of stem cell-based pulp and dentin regeneration: a clinical perspective.

PubMed

Huang, George T-J; Al-Habib, Mey; Gauthier, Philippe

2013-03-01

There are two types of approaches to regenerate tissues: cell-based and cell-free. The former approach is to introduce exogenous cells into the host to regenerate tissues, and the latter is to use materials other than cells in an attempt to regenerate tissues. There has been a significant advancement in stem cell-based pulp and dentin regeneration research in the past few years. Studies in small and large animals have demonstrated that pulp/dentin-like tissues can be regenerated partially or completely in the root canal space with apical openings of 0.7-3.0 mm using dental pulp stem cells, including stem cells from apical papilla (SCAP) and subpopulations of pulp stem cells. Bone marrow mesenchymal stem cells (BMMSCs) and adipose tissue-derived MSCs (ADMSCs) have also been shown to regenerate pulp-like tissue. In contrast, the cell-free approach has not produced convincing evidence on pulp regeneration. However, one crucial concept has not been considered nor defined in the field of pulp/dentin regeneration and that is the critical size defect of dentin and pulp. Without such consideration and definition, it is difficult to predict or anticipate the extent of cell-free pulp regeneration that would occur. By reasoning, cell-free therapy is unlikely to regenerate an organ/tissue after total loss. Similarly, after a total loss of pulp, it is unlikely to regenerate without using exogenously introduced cells. A cell homing approach may provide a limited amount of tissue regeneration. Although stem cell-based pulp/dentin regeneration has shown great promise, clinical trials are difficult to launch at present. This article will address several issues that challenge and hinder the clinical applications of pulp/dentin regeneration which need to be overcome before stem cell-based pulp/dentin regeneration can occur in the clinic.

Challenges of stem cell-based pulp and dentin regeneration: a clinical perspective

PubMed Central

HUANG, GEORGE T.-J.; AL-HABIB, MEY; GAUTHIER, PHILIPPE

2013-01-01

There are two types of approaches to regenerate tissues: cell-based and cell-free. The former approach is to introduce exogenous cells into the host to regenerate tissues, and the latter is to use materials other than cells in an attempt to regenerate tissues. There has been a significant advancement in stem cell-based pulp and dentin regeneration research in the past few years. Studies in small and large animals have demonstrated that pulp/dentin-like tissues can be regenerated partially or completely in the root canal space with apical openings of 0.7-3.0 mm using dental pulp stem cells, including stem cells from apical papilla (SCAP) and subpopulations of pulp stem cells. Bone marrow mesenchymal stem cells (BMMSCs) and adipose tissue-derived MSCs (ADMSCs) have also been shown to regenerate pulp-like tissue. In contrast, the cell-free approach has not produced convincing evidence on pulp regeneration. However, one crucial concept has not been considered nor defined in the field of pulp/dentin regeneration and that is the critical size defect of dentin and pulp. Without such consideration and definition, it is difficult to predict or anticipate the extent of cell-free pulp regeneration that would occur. By reasoning, cell-free therapy is unlikely to regenerate an organ/tissue after total loss. Similarly, after a total loss of pulp, it is unlikely to regenerate without using exogenously introduced cells. A cell homing approach may provide a limited amount of tissue regeneration. Although stem cell-based pulp/dentin regeneration has shown great promise, clinical trials are difficult to launch at present. This article will address several issues that challenge and hinder the clinical applications of pulp/dentin regeneration which need to be overcome before stem cell-based pulp/dentin regeneration can occur in the clinic. PMID:23914150

Stem cell research: applicability in dentistry.

PubMed

Mathur, Shivani; Chopra, Rahul; Pandit, I K; Srivastava, Nikhil; Gugnani, Neeraj

2014-01-01

In the face of extraordinary advances in the prevention, diagnosis, and treatment of human diseases, the inability of most tissues and organs to repair and regenerate after damage is a problem that needs to be solved. Stem cell research is being pursued in the hope of achieving major medical breakthroughs. Scientists are striving to create therapies that rebuild or replace damaged cells with tissues grown from stem cells that will offer hope to people suffering from various ailments. Regeneration of damaged periodontal tissue, bone, pulp, and dentin is a problem that dentists face today. Stem cells present in dental pulp, periodontal ligament, and alveolar bone marrow have the potential to repair and regenerate teeth and periodontal structures. These stem cells can be harvested from dental pulp, periodontal ligament, and/or alveolar bone marrow; expanded; embedded in an appropriate scaffold; and transplanted back into a defect to regenerate bone and tooth structures. These cells have the potential to regenerate dentin, periodontal ligament, and cementum and can also be used to restore bone defects. The kind of scaffold, the source of cells, the type of in vitro culturing, and the type of surgical procedure to be used all require careful consideration. The endeavor is clearly multidisciplinary in nature, and the practicing dental surgeon has a critical role in it. Playing this role in the most effective way requires awareness of the huge potential associated with the use of stem cells in a clinical setting, as well as a proper understanding of the related problems.

Porous microscaffolds for 3D culture of dental pulp mesenchymal stem cells.

PubMed

Bhuptani, Ronak S; Patravale, Vandana B

2016-12-30

The collective power of stem cells due to their evident advantages is incessantly investigated in regenerative medicine to be the next generation exceptional remedy for tissue regeneration and treatment of diseases. Stem cells are highly sensitive and a 3D culture environment is a requisite for its successful transplantation and integration with tissues. Porous microscaffolds can create a 3D microenvironment for growing stems cells, controlling their fate both in vitro and in vivo. In the present study, interconnected porous PLGA microscaffolds were fabricated, characterized and employed to propagate human dental pulp mesenchymal stem cells (DPMSCs) in vitro. The porous topography was investigated by scanning electron microscopy and the pore size was controlled by fabrication conditions such as the concentration of porogen. DPMSCs were cultured on microscaffolds and were evaluated for their morphology, attachment, proliferation, cell viability via MTT and molecular expression (RT-PCR). DPMSCs were adequately proliferated and adhered over the microscaffolds forming a 3D cell-microscaffold construct. The average number of DPMSCs grown on PLGA microscaffolds was significantly higher than monolayer 2D culture during 5th and 7th day. Moreover, cell viability and gene expression results together corroborated that microscaffolds maintained the viability, stemness and plasticity of the cultured dental pulp mesenchymal stem cells. The novel porous microscaffold developed acts as promising scaffold for 3D culture and survival and transplantation of stem cells for tissue engineering. Copyright © 2016 Elsevier B.V. All rights reserved.

Osteogenesis and angiogenesis properties of dental pulp cell on novel injectable tricalcium phosphate cement by silica doped.

PubMed

Su, Ying-Fang; Lin, Chi-Chang; Huang, Tsui-Hsien; Chou, Ming-Yung; Yang, Jaw-Ji; Shie, Ming-You

2014-09-01

β-Tricalcium phosphate (β-TCP) is an osteoconductive material in clinical. In this study, we have doped silica (Si) into β-TCP and enhanced its bioactive and osteostimulative properties. To check its effectiveness, a series of Si-doped with different ratios were prepared to make new bioactive and biodegradable biocomposites for bone repair. Formation of the diametral tensile strength, ions released and weight loss of cements was considered after immersion. In addition, we also examined the behavior of human dental pulp cells (hDPCs) cultured on Si-doped β-TCP cements. The results showed that setting time and injectability of the Si-doped β-TCP cements were decreased as the Si content was increased. At the end of the immersion point, weight losses of 30.1%, 36.9%, 48.1%, and 55.3% were observed for the cement doping 0%, 10%, 20%, and 30% Si into β-TCP cements, respectively. In vitro cell experiments show that the Si-rich cements promote human dental pulp cell (hDPC) proliferation and differentiation. However, when the Si-doped in the cement is more than 20%, the amount of cells and osteogenesis protein of hDPCs was stimulated by Si released from Si-doped β-TCP cements. The degradation of β-TCP and osteogenesis of Si gives a strong reason to believe that these Si-doped β-TCP cements may prove to be promising bone repair materials. Copyright © 2014 Elsevier B.V. All rights reserved.

p75 neurotrophin receptor positive dental pulp stem cells: new hope for patients with neurodegenerative disease and neural injury.

PubMed

Dai, Jie-wen; Yuan, Hao; Shen, Shun-yao; Lu, Jing-ting; Zhu, Xiao-fang; Yang, Tong; Zhang, Jiang-fei; Shen, Guo-fang

2013-08-01

Neurodegenerative diseases and neural injury are 2 of the most feared disorders that afflict humankind by leading to permanent paralysis and loss of sensation. Cell based treatment for these diseases had gained special interest in recent years. Previous studies showed that dental pulp stem cells (DPSCs) could differentiate toward functionally active neurons both in vitro and in vivo, and could promote neuranagenesis through both cell-autonomous and paracrine neuroregenerative activities. Some of these neuroregenerative activities were unique to tooth-derived stem cells and superior to bone marrow stromal cells. However, DPSCs used in most of these studies were mixed and unfractionated dental pulp cells that contain several types of cells, and most were fibroblast cells while just contain a small portion of DPSCs. Thus, there might be weaker ability of neuranagenesis and more side effects from the fibroblast cells that cannot differentiate into neural cells. p75 neurotrophin receptor (p75NTR) positive DPSCs subpopulation was derived from migrating cranial neural crest cells and had been isolated from DPSCs, which had capacity of differentiation into neurons and repairing neural system. In this article, we hypothesize that p75NTR positive DPSCs simultaneously have greater propensity for neuronal differentiation and fewer side effects from fibroblast, and in vivo transptantation of autologous p75NTR positive DPSCs is a novel method for neuranagenesis. This will bring great hope to patients with neurodegenerative disease and neural injury.

Tissue Engineering Considerations in Dental Pulp Regeneration

PubMed Central

Nosrat, Ali; Kim, Jong Ryul; Verma, Prashant; S. Chand, Priya

2014-01-01

Regenerative endodontic procedure is introduced as a biologically based treatment for immature teeth with pulp necrosis. Successful clinical and radiographic outcomes following regenerative procedures have been reported in landmark case reports. Retrospective studies have shown that this conservative treatment allows for continued root development and increases success and survival rate of the treated teeth compared to other treatment options. Although the goal of treatment is regeneration of a functional pulp tissue, histological analyses show a different outcome. Developing predictable protocols would require the use of key elements for tissue engineering: stem cells, bioactive scaffolds, and growth factors. In this study we will review the evidence based steps and outcomes of regenerative endodontics. PMID:24396373

Regenerative Endodontics: A Road Less Travelled

PubMed Central

Bansal, Ramta; Mittal, Sunandan; Kumar, Tarun; Kaur, Dilpreet

2014-01-01

Although traditional approaches like root canal therapy and apexification procedures have been successful in treating diseased or infected root canals, but these modalities fail to re-establish healthy pulp tissue in treated teeth. Regeneration-based approaches aims to offer high levels of success by replacing diseased or necrotic pulp tissues with healthy pulp tissue to revitalize teeth. The applications of regenerative approaches in dental clinics have potential to dramatically improve patients’ quality of life. This review article offers a detailed overview of present regenerative endodontic approaches aiming to revitalize teeth and also outlines the problems to be dealt before this emerging field contributes to clinical treatment protocols. It conjointly covers the basic trilogy elements of tissue engineering. PMID:25478476

Biocompatability of compomer restorative systems on nonexposed dental pulps of primate teeth.

PubMed

Tarim, B; Hafez, A A; Suzuki, S H; Suzuki, S; Cox, C F

1997-01-01

This study evaluated the histologic response of total-etched and nonetched compomer restored cavity preparations. One hundred fifteen class 5 cavity preparations were placed in the teeth of four healthy adult monkeys at 7, 27, and 90 days. A 37% H3PO4 was applied for 10 seconds and rinsed in total-etched preparations. No statistical differences were seen in inflammatory reactions among total-etched or nonetched compomers at 7, 27, and 90 days. There were no statistical differences in inflammatory cell responses among all compomer systems in regard to time intervals. Pulpal responses of compomers were greater than IRM at each time period. Pulp responses were associated with stained bacteria in 32 of 89 compomer teeth. No necrotic pulps were seen in any teeth. Statistical data show a positive correlation (P < 0.05) between bacterial presence and pulpal inflammation. IRM pulps showed no inflammation or bacterial staining. Compomers are biologically compatible with pulp tissues when bacteria are excluded.

Aspects of dentinal and pulpal pain. Pain of dentinal and pulpal origin--a review for the clinician.

PubMed

Figdor, D

1994-04-01

Recent advances in understanding the mechanisms of pain arising from the dental pulp serve to benefit patients by improving the clinician's ability to diagnose and treat pain. There are two types of pain arising from the pulp which are mediated by entirely different nerve fibres, each with their own individual characteristics. One is a short, sharp fast pain which is induced by stimuli which cause a rapid fluid flow within the dentinal tubules. Such stimuli include cold, heat, air, drilling, and osmotic stimuli. Once the affected teeth are identified, they can often be treated by sealing the open, exposed dentine. The second type of pain is experienced as a slow, dull, aching, poorly localized pain which is mediated by pain fibres activated by stimuli which are noxious to the pulp, such as prolonged damaging heat and inflammatory mediators. Pain of this character can be difficult to diagnose and often indicates serious pulp damage necessitating removal of the offending pulp by endodontic therapy.

Substance P influenced gelatinolytic activity via reactive oxygen species in human pulp cells.

PubMed

Wang, F-M; Hu, T; Cheng, R; Tan, H; Zhou, X-D

2008-10-01

To investigate the effects of substance P (SP) on gelatinolytic activity of matrix metalloproteinases (MMPs) in human pulp cells. Human dental pulp cells were isolated and cultured. Subconfluent cells, between the third and sixth passages, were maintained under serum deprivation for 18 h followed by the treatment of varying doses of SP (1 pmol L(-1), 100 pmol L(-1), 10 nmol L(-1), 1 micromol L(-1) and 100 micromol L(-1)). Conditioned media were then subjected to gelatin zymography using 8% sodium dodecyl sulphate polyacrylamide gel electrophoresis minigels containing 1.5 g L(-1) gelatin. The effect of SP on intracellular reactive oxygen species (ROS) was also examined by confocal microscopy. ROS scavenger N-Acetyl-L-cysteine (NAC, 5 mmol L(-1)) was utilized to evaluate the roles of ROS pathway in mediating the impact of SP on cellular gelatinolytic activity. Data were analysed using analysis of variance with Bonferroni correction for multiple comparisons or an unpaired Student's t-test. Substance P, at levels above 1 micromol L(-1), remarkably enhanced MMP-2 activity reflected by the band migrating at 66 kDa (P < 0.05). A gelatinolytic band at approximately 44 kDa appeared to be intensified in a SP dose-dependent manner. In addition, it was demonstrated that SP could induce ROS production in pulp cells and ROS scavenger NAC was further found to significantly reduce MMP-2 activity (P < 0.05), as well as other bands of gelatinolytic proteinases. Substance P can influence gelatinolytic activity in human pulp cells via ROS pathway.

Spontaneous Differentiation of Dental Pulp stem cells on Dental polymers

NASA Astrophysics Data System (ADS)

Bherwani, Aneel; Suarato, Giulia; Qin, Sisi; Chang, Chung-Cheh; Akhavan, Aaron; Spiegel, Joseph; Jurukovski, Vladimir; Rafailovich, Miriam; Simon, Marcia

2012-02-01

Dental pulp stem cells were plated on two dentally relevant materials i.e. PMMA commonly used for denture and Titanium used for implants. In both cases, we probed for the role of surface interaction and substrate morphology. Different films of PMMA were spun cast directly onto Si wafers; PMMA fibers of different diameters were electro spun onto some of these substrates. Titanium metal was evaporated onto Si surfaces using an electron beam evaporator. In addition, on some surfaces, P4VP nanofibers were spun cast. DPSC were grown in alpha-MEM supplemented with 10% fetal bovine serum, 0.2mM L-ascorbic acid 2-phosphate, 2mm glutamine and 10mM beta-glycerol phosphate either with or without 10nM dexamethasone. After 21 days samples were examined using confocal microscopy of cells and by scanning electron microscopy (SEM) and Energy dispersive X-ray Analysis (EDAX). In the case of Titanium biomineralization was observed independent of dexamethasone, where the deposits were templated along the fibers. Minimal biomineralization was observed on flat Titanium and PMMA samples. Markers of osteogenesis and specific signaling pathways are being evaluated by RT-PCR, which are up regulated on each surface, to understand the fundamental manner in which surfaces interact with cell differentiation.

Dental Age Estimation Helps Create a New Identity.

PubMed

De Angelis, Danilo; Gibelli, Daniele; Fabbri, Paolo; Cattaneo, Cristina

2015-09-01

Age estimation involves the reconstruction of age by biological parameters such as skeletal and dental development in minors, or reduction of pulp chamber in adults, to gain indications concerning the chronological age of the person. In most cases, it is needed in forensic scenarios to verify if the supposed age of an individual is correct; in exceptional cases, age estimation is instead required by judicial authorities to create a new identity usually in persons who do not remember who they are.This article aims at reporting the case of J. who was found in 2005 with signs of amnesia because he did not remember his name and age. After several unsuccessful attempts at identifying him, the judicial authority decided to assign a new identity, which was to be constructed according to the real biological data of the individual. The help of a forensic pathologist and a forensic odontologist was then requested, and age estimation was reached by applying methods for adults based on the physiological reduction of pulp chamber. Dental age estimation yielded a final result of approximately 31 years, which was the new age assigned to the person.This article shows a peculiar application of dental age estimation, which can be used not only to ascertain or deny supposed age, but is sometimes needed to create a new identity.

Pulsed Nd:YAG laser selective ablation of surface enamel caries: II. Histology and clinical trials

NASA Astrophysics Data System (ADS)

Harris, David M.; Goodis, Harold E.; White, Joel M.; Arcoria, Charles J.; Simon, James; Burkart, John; Yessik, Michael J.; Myers, Terry D.

2000-03-01

High intensity infrared light from the pulsed Nd:YAG dental laser is absorbed by pigmented carious enamel and not absorbed by normal enamel. Therefore, this system is capable of selective removal of surface enamel caries. Safety and efficacy of the clinical procedure was evaluated in two sets of clinical trials at three dental schools. Carious lesions were randomized to drill or laser treatment. Pulp vitality, surface condition, preparations and restorations were evaluated by blinded evaluators. In Study 1 surface caries were removed from 104 third molars scheduled for extraction. One week post-treatment teeth were extracted and the pulp was examined histologically. In Study 2 90 patients with 422 lesions on 376 teeth were randomized to laser or drill and followed for six months. There were no adverse events and both clinical and histological evaluations of pulp vitality showed no abnormalities. Caries were removed in all conditions. A significantly greater number of preparations in the drill groups vs. laser groups entered dentin (drill equals 11, laser equals 1, p less than 0.001). This indicates that the more conservative laser treatment removed the caries but not the sound enamel below the lesion.

Pulpal perio relations: Interdisciplinary diagnostic approach - I

PubMed Central

Nirola, Ashutosh; Grover, Sunanda; Sharma, Ajay; Kaur, Damanjeet

2011-01-01

Lesions of pulpal and periodontal origin may perpetuate from either the infections of dental pulp or periodontium or alveolar bone. This review focuses on interdisciplinary diagnostic approach towards lesions of periodontal or endodontic origin. PMID:21772729

From the Cover: Activation of NF-κB-Autophagy Axis by 2-Hydroxyethyl Methacrylate Commits Dental Mesenchymal Cells to Apoptosis.

PubMed

Yu, Jing-Jing; Zhu, Ling-Xin; Zhang, Jie; Liu, Shan; Lv, Feng-Yuan; Cheng, Xue; Liu, Guo-Jing; Peng, Bin

2017-05-01

2-hydroxyethyl methacrylate (HEMA) is the major resin monomer that is released from incomplete polymerized dental restorative and adhesive biomaterials during dental therapy. Autophagy and apoptosis are biologically connected and the relationship between autophagy and apoptosis is complex under various circumstances. This study aimed to determine whether autophagy is activated by HEMA and further explore the function of autophagy during the HEMA-induced apoptosis of dental mesenchymal cells (DMCs). We exposed DMCs to different concentrations of HEMA. Cell viability showed a time- and concentration-dependent decrease when exposed to HEMA. We showed that HEMA exposure increased autophagic vacuoles and the expression of autophagic biomarkers (Beclin1, Atg5 and LC3). Pre-incubated with autophagy inhibitors (3-methyladenine and chloroquine) significantly prevented HEMA-induced apoptosis. Interestingly, HEMA initiated nuclear factor-κB (NF-κB) expression and nuclear translocation, whereas the NF-κB inhibitor (Bay 11-7082) markedly suppressed HEMA-induced autophagic activation and apoptosis. As is consistent with the in vitro results, HEMA treatment resulted in dental pulp tissue toxicity and activation of typical autophagic vacuoles in the tooth slice organ culture model ex vivo. In summary, we demonstrated that NF-κB signaling functioned upstream of HEMA-inducecd autophagy in DMCs and that the activation of NF-κB-autophagy axis was responsible for HEMA-induced apoptosis. Our findings provide novel insights into the mechanisms of resin monomer-mediated dental pulp damage during dental treatment, highlighting the activation of NF-κB-autophagy axis as an important mechanism of HEMA-mediated apoptosis. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Dental neglect among children in Chennai.

PubMed

Gurunathan, Deepa; Shanmugaavel, Arunachalam Karthikeyan

2016-01-01

Child dental neglect is the failure of a parent or guardian to meet the child's basic oral health needs such that the child enjoys adequate function and freedom from pain and infection, where reasonable resources are available to family or caregiver. The aim of the study is to evaluate the phenomenon of dental neglect among children in Chennai and to associate dental neglect with oral health status of children aged 3-12 years. This is a cross-sectional study involving 478 pairs of parents and children. Dental neglect scale and a questionnaire were used to assess the dental neglect score among parents of the children involved in the study. Oral health status of children was clinically assessed using oral hygiene index, decayed, extracted, filled teeth (def(t)), pulp, ulcers, fistula, abscess (pufa), decayed, missing, filled teeth (DMFT), PUFA as per the World Health Organization criteria and pufa/PUFA index. Student's t-test and one-way ANOVA were used appropriately for statistical analysis using SPSS software version 20.0. A significant higher dental neglect score was reported among the parents who reside in the suburban location (P < 0.001), whose educational qualification was secondary (P < 0.001) and who have not availed any dental service for >3 years (P = 0.001). A significant higher DMFT (P = 0.003), deft (P = 0 < 0.001), pufa (P = 0.011), and debris index (P = 0.002) scores were seen in the higher dental neglect group. Child dental neglect is seen among the parents whose educational qualification was secondary, who reside in the suburban location, and who have not utilized the dental services for more than 3 years in Chennai. This dental neglect results in poorer oral health of children.

Dens invaginatus with necrotic pulp in a right maxillary lateral incisor with preserved vitality.

PubMed

Alessandro, Lanza; Fabrizio, Di Francesco; Gennaro, De Marco; Dario, Di Stasio; Eugenio, Guidetti; Letizia, Perillo; Luigi, Femiano; Felice, Femiano

2018-01-01

Dens invaginatus (DI) is a dental malformation occurring in several morphologic types. Consequently, treatment of teeth affected by DI can get complicated because of the complex root canal anatomy. The aim is to describe how to manage a rare report of a DI with necrotic pulp held within the vital pulp of a maxillary lateral incisor. Oral fistula was found on the buccal mucosa of the apex of the vital maxillary lateral incisor with a DI having necrotic pulp. Endodontic treatment of the maxillary lateral incisor and of the tract canal of DI was realized. Clinical disappearance of oral sinus tract was observed after 10 days. On the contrary, the disappearance of radiolucent area occurred after 6 months. A proper and prompt diagnosis is necessary to carry out effective prevention protocols or prevent consequences generating nonrecoverable endo-perio diseases.

Designing and testing regenerative pulp treatment strategies: modeling the transdentinal transport mechanisms

PubMed Central

Passos, Agathoklis D.; Mouza, Aikaterini A.; Paras, Spiros V.; Gogos, Christos; Tziafas, Dimitrios

2015-01-01

The need for simulation models to thoroughly test the inflammatory effects of dental materials and dentinogenic effects of specific signaling molecules has been well recognized in current dental research. The development of a model that simulates the transdentinal flow and the mass transfer mechanisms is of prime importance in terms of achieving the objectives of developing more effective treatment modalities in restorative dentistry. The present protocol study is part of an ongoing investigation on the development of a methodology that can calculate the transport rate of selected molecules inside a typical dentinal tubule. The transport rate of biological molecules has been investigated using a validated CFD code. In that framework we propose a simple algorithm that, given the type of molecules of the therapeutic agent and the maximum acceptable time for the drug concentration to attain a required value at the pulpal side of the tubules, can estimate the initial concentration to be imposed. PMID:26441676

Confocal Raman microscopy to monitor extracellular matrix during dental pulp stem cells differentiation

NASA Astrophysics Data System (ADS)

Salehi, Hamideh; Collart-Dutilleul, Pierre-Yves; Gergely, Csilla; Cuisinier, Frédéric J. G.

2015-07-01

Regenerative medicine brings promising applications for mesenchymal stem cells, such as dental pulp stem cells (DPSCs). Confocal Raman microscopy, a noninvasive technique, is used to study osteogenic differentiation of DPSCs. Integrated Raman intensities in the 2800 to 3000 cm-1 region (C-H stretching) and the 960 cm-1 peak (ν1 PO43-) were collected (to image cells and phosphate, respectively), and the ratio of two peaks 1660 over 1690 cm-1 (amide I bands) to measure the collagen cross-linking has been calculated. Raman spectra of DPSCs after 21 days differentiation reveal several phosphate peaks: ν1 (first stretching mode) at 960 cm-1, ν2 at 430 cm-1, and ν4 at 585 cm-1 and collagen cross-linking can also be calculated. Confocal Raman microscopy enables monitoring osteogenic differentiation in vitro and can be a credible tool for clinical stem cell based research.

Evaluation of radiographs, clinical signs and symptoms associated with pulp canal obliteration: an aid to treatment decision.

PubMed

Oginni, Adeleke O; Adekoya-Sofowora, Comfort A; Kolawole, Kikelomo A

2009-12-01

Pulp canal obliteration (PCO) is a sequela of tooth trauma. The dental clinician faced with this condition has to make a difficult decision. The aim of this study was to evaluate the clinical signs and symptoms associated with teeth with PCO and to assess the status of the periapical tissues using the periapical index (PAI) as an aid in making a treatment decision. The study included teeth diagnosed with PCO in patients with a history of traumatic injury to the involved teeth. Histories of associated signs and symptoms including pain, swelling and drainage from a sinus tract were elicited. Tooth color, sensibility to electric pulp testing, mobility and percussion tenderness were recorded. The periapical status was assessed using the PAI. Two hundred and seventy-six teeth were diagnosed with PCO. One hundred and fifty-seven (56.9%) and 119 (43.1%) demonstrated partial or total PCO, respectively. Yellow discoloration presented most frequently, occurring in 186 (67.4%) teeth. Sixty-two (33.3%) of these had developed periapical lesions and reacted negatively to sensibility testing. Fifty-seven (30.7%) of these teeth presented radiographically with a normal periapical appearance and reacted normally to sensibility testing, whereas 67 (36.0%) presented with small changes in the periapical bone pattern and reacted in the high normal range to sensibility testing. Teeth with PAI scores < or =2 presented with occasional spontaneous pain. Teeth with PAI scores > or =3 presented with clinical symptoms and signs ranging from pain on percussion to spontaneous pain, and slight swelling to sinus tract drainage. Based on the findings of this study, endodontic treatment should be initiated in teeth with tenderness to percussion, PAI scores > or =3 and a negative response to sensibility testing.

A 2-year retrospective study of pediatric dental emergency visits at a hospital emergency center in Taiwan.

PubMed

Jung, Chia-Pei; Tsai, Aileen I; Chen, Ching-Ming

2016-06-01

There is a paucity of information regarding pediatric dental emergencies in Taiwan. This study investigates the prevalence and characteristics of the pediatric dental emergency services provided at a medical center. This study included a retrospective chart review of patients under 18 years of age with dental complaints who visited the Emergency Department (ED) of Linkou Medical Center of Chang Gung Memorial Hospital from January 2012 to December 2013. Information regarding age, gender, time/day/month of presentation, diagnosis, treatment, and follow-up was collected and analyzed. Statistical analysis included descriptive statistics and Pearson's Chi-square test with the significance level set as p < 0.05. This study revealed that dental emergencies in the medical center ED were predominantly related to orodental trauma (47.1%) and pulpal pain (29.9%). Most patients were male (p < 0.001) and <5 years of age (p < 0.001). The most frequent orodental trauma was luxation, both in primary and permanent dentition. The major management for dental emergencies was prescribing medication for pulp-related problems and orodental trauma. The follow-up rate of orodental trauma was the highest (p < 0.001). For children, trauma and toothache constituted the most common reasons for dental emergency visits at a hospital emergency center in Taiwan. While dental emergencies are sometimes unforeseeable or unavoidable, developing community awareness about proper at-home care as well as regular dental preventive measures can potentially reduce the number of emergency visits. Copyright © 2016 Chang Gung University. Published by Elsevier B.V. All rights reserved.

Histopathological changes in dental pulp of rats following radiotherapy

PubMed Central

Madani, Zahra Sadat; Azarakhsh, Soheil; Shakib, Pouyan Amini; Karimi, Masoomeh

2017-01-01

Background: Radiotherapy is one of the oral and pharyngeal cancer treatment methods that can cause damage to the tissues in the radiation area; the purpose of this study is to evaluate the effects of radiotherapy on dental pulp tissue in rats. Materials and Methods: In this interventional, experimental double-blind study, 30 rats were studied in three groups (n = 10 each). The first group received 12 gray (Gy), the second group received 18 Gy in one session, and the third group was not exposed to radiation (control group). The 5 μm sections of mandibular molar tooth were prepared and stained with hematoxylin and eosin. Samples were studied under optical microscope to evaluate and score inflammation, necrosis, hyalinization, and vascular congestion. The data were coded and analyzed by statistical tests of χ2 and Fisher's exact tests. The significant level of P = 0.05. Results: In Group 1, necrosis in two cases, inflammation in one case, hyalinization in one case, and vascular congestion in four cases were observed. In Group 2, inflammation in four cases, hyalinization in two cases, and vascular congestion in five cases were observed. In Group 3, inflammation was observed only in one case. In comparison between the groups, no significant differences were observed in inflammation (P > 0.05), necrosis (P > 0.05), and hyalinization (P > 0.05). However, the difference was significant for vascular congestion (P < 0.05). Conclusion: Radiotherapy with doses of 12 and 18 Gy had no significant effect on inflammation, necrosis, and hyalinization in all groups; however, the difference was significant for vascular congestion. PMID:28348613

Collagenous matrix supported by a 3D-printed scaffold for osteogenic differentiation of dental pulp cells.

PubMed

Fahimipour, Farahnaz; Dashtimoghadam, Erfan; Rasoulianboroujeni, Morteza; Yazdimamaghani, Mostafa; Khoshroo, Kimia; Tahriri, Mohammadreza; Yadegari, Amir; Gonzalez, Jose A; Vashaee, Daryoosh; Lobner, Douglas C; Jafarzadeh Kashi, Tahereh S; Tayebi, Lobat

2018-02-01

A systematic characterization of hybrid scaffolds, fabricated based on combinatorial additive manufacturing technique and freeze-drying method, is presented as a new platform for osteoblastic differentiation of dental pulp cells (DPCs). The scaffolds were consisted of a collagenous matrix embedded in a 3D-printed beta-tricalcium phosphate (β-TCP) as the mineral phase. The developed construct design was intended to achieve mechanical robustness owing to 3D-printed β-TCP scaffold, and biologically active 3D cell culture matrix pertaining to the Collagen extracellular matrix. The β-TCP precursor formulations were investigated for their flow-ability at various temperatures, which optimized for fabrication of 3D printed scaffolds with interconnected porosity. The hybrid constructs were characterized by 3D laser scanning microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and compressive strength testing. The in vitro characterization of scaffolds revealed that the hybrid β-TCP/Collagen constructs offer superior DPCs proliferation and alkaline phosphatase (ALP) activity compared to the 3D-printed β-TCP scaffold over three weeks. Moreover, it was found that the incorporation of TCP into the Collagen matrix improves the ALP activity. The presented results converge to suggest the developed 3D-printed β-TCP/Collagen hybrid constructs as a new platform for osteoblastic differentiation of DPCs for craniomaxillofacial bone regeneration. Copyright © 2017. Published by Elsevier Ltd.

An ex vivo comparison of pressures within dental pulp space using conventional anesthetic technique versus needle-mounted obturator.

PubMed

Grubbs, S Lee; Alley, Larry W; Eleazer, Paul D

2014-07-01

The intrapulpal (IP) injection technique is 1 of several ways of obtaining profound anesthesia. There is evidence to suggest that pressure is the primary factor in obtaining anesthesia using IP injection. This is an ex vivo comparison of pressures within dental pulp space using the conventional anesthetic technique versus a needle-mounted obturator technique. Twenty extracted anterior and premolar teeth were accessed with a high-speed 169L bur. A saline-filled tube connected to a digital pressure gauge was attached to the apical 10 mm of each tooth in a fixed mount. One operator performed all the injections under moderate pressure. Each tooth was injected twice; first, the tooth was given an IP injection with a normal setup, and then the same tooth was given an IP injection with the modified obturator syringe. The pressure at the apex was recorded for each tooth. A paired sample t test was completed to determine statistical significance. The pressure generated was considerably higher for the obturator group in every tooth when compared with the normal group (P < .001). IP injection with the obturator resulted in increased pressure at the apex of each tooth. This pressure increase may allow for increased anesthesia when IP injections are indicated. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Polymeric vs hydroxyapatite-based scaffolds on dental pulp stem cell proliferation and differentiation

PubMed Central

Khojasteh, Arash; Motamedian, Saeed Reza; Rad, Maryam Rezai; Shahriari, Mehrnoosh Hasan; Nadjmi, Nasser

2015-01-01

AIM: To evaluate adhesion, proliferation and differentiation of human dental pulp stem cells (hDPSCs) on four commercially available scaffold biomaterials. METHODS: hDPSCs were isolated from human dental pulp tissues of extracted wisdom teeth and established in stem cell growth medium. hDPSCs at passage 3-5 were seeded on four commercially available scaffold biomaterials, SureOss (Allograft), Cerabone (Xenograft), PLLA (Synthetic), and OSTEON II Collagen (Composite), for 7 and 14 d in osteogenic medium. Cell adhesion and morphology to the scaffolds were evaluated by scanning electron microscopy (SEM). Cell proliferation and differentiation into osteogenic lineage were evaluated using DNA counting and alkaline phosphatase (ALP) activity assay, respectively. RESULTS: All scaffold biomaterials except SureOss (Allograft) supported hDPSC adhesion, proliferation and differentiation. hDPSCs seeded on PLLA (Synthetic) scaffold showed the highest cell proliferation and attachment as indicated with both SEM and DNA counting assay. Evaluating the osteogenic differentiation capability of hDPSCs on different scaffold biomaterials with ALP activity assay showed high level of ALP activity on cells cultured on PLLA (Synthetic) and OSTEON II Collagen (Composite) scaffolds. SEM micrographs also showed that in the presence of Cerabone (Xenograft) and OSTEON II Collagen (Composite) scaffolds, the hDPSCs demonstrated the fibroblastic phenotype with several cytoplasmic extension, while the cells on PLLA scaffold showed the osteoblastic-like morphology, round-like shape. CONCLUSION: PLLA scaffold supports adhesion, proliferation and osteogenic differentiation of hDPSCs. Hence, it may be useful in combination with hDPSCs for cell-based reconstructive therapy. PMID:26640621

Transplantation of Hepatocyte Growth Factor-Modified Dental Pulp Stem Cells Prevents Bone Loss in the Early Phase of Ovariectomy-Induced Osteoporosis.

PubMed

Kong, Fanxuan; Shi, Xuefeng; Xiao, Fengjun; Yang, Yuefeng; Zhang, Xiaoyan; Wang, Li-Sheng; Wu, Chu-Tse; Wang, Hua

2018-02-01

Investigations based on mesenchymal stem cells (MSCs) for osteoporosis have attracted attention recently. MSCs can be derived from various tissues, such as bone marrow, adipose, umbilical cord, placenta, and dental pulp. Among these, dental pulp-derived MSCs (DPSCs) and hepatocyte growth factor (HGF)-modified DPSCs (DPSCs-HGF) highly express osteogenic-related genes and have stronger osteogenic differentiation capacities. DPSCs have more benefits in treating osteoporosis. The purpose of this study was to investigate the roles of HGF gene-modified DPSCs in bone regeneration using a mouse model of ovariectomy (OVX)-induced bone loss. The HGF and luciferase genes were transferred into human DPSCs using recombinant adenovirus. These transduced cells were assayed for distribution or bone regeneration assay by transplantation into an OVX-induced osteoporosis model. By using bioluminogenic imaging, it was determined that some DPSCs could survive for >1 month in vivo. The DPSCs were mainly distributed to the lung in the early stage and to the liver in the late stage of OVX osteoporosis after administration, but they were scarcely distributed to the bone. The homing efficiency of DPSCs is higher when administrated in the early stage of a mouse OVX model. Micro-computed tomography indicated that DPSCs-Null or DPSCs-HGF transplantation significantly reduces OVX-induced bone loss in the trabecular bone of the distal femur metaphysis, and DPSCs-HGF show a stronger capacity to reduce bone loss. The data suggest that systemic infusion of DPSCs-HGF is a potential therapeutic approach for OVX-induced bone loss, which might be mediated by paracrine mechanisms.

Ionotropic P2X ATP Receptor Channels Mediate Purinergic Signaling in Mouse Odontoblasts

PubMed Central

Shiozaki, Yuta; Sato, Masaki; Kimura, Maki; Sato, Toru; Tazaki, Masakazu; Shibukawa, Yoshiyuki

2017-01-01

ATP modulates various functions in the dental pulp cells, such as intercellular communication and neurotransmission between odontoblasts and neurons, proliferation of dental pulp cells, and odontoblast differentiation. However, functional expression patterns and their biophysical properties of ionotropic ATP (P2X) receptors (P2X1–P2X7) in odontoblasts were still unclear. We examined these properties of P2X receptors in mouse odontoblasts by patch-clamp recordings. K+-ATP, nonselective P2X receptor agonist, induced inward currents in odontoblasts in a concentration-dependent manner. K+-ATP-induced currents were inhibited by P2X4 and P2X7 selective inhibitors (5-BDBD and KN62, respectively), while P2X1 and P2X3 inhibitors had no effects. P2X7 selective agonist (BzATP) induced inward currents dose-dependently. We could not observe P2X1, 2/3, 3 selective agonist (αβ-MeATP) induced currents. Amplitudes of K+-ATP-induced current were increased in solution without extracellular Ca2+, but decreased in Na+-free extracellular solution. In the absence of both of extracellular Na+ and Ca2+, K+-ATP-induced currents were completely abolished. K+-ATP-induced Na+ currents were inhibited by P2X7 inhibitor, while the Ca2+ currents were sensitive to P2X4 inhibitor. These results indicated that odontoblasts functionally expressed P2X4 and P2X7 receptors, which might play an important role in detecting extracellular ATP following local dental pulp injury. PMID:28163685

In vitro effects of two silicate-based materials, Biodentine and BioRoot RCS, on dental pulp stem cells in models of reactionary and reparative dentinogenesis

PubMed Central

Loison-Robert, Ludwig Stanislas; Berbar, Tsouria; Isaac, Juliane; Berdal, Ariane; Simon, Stéphane

2018-01-01

Background Calcium silicate-based cements are biomaterials with calcium oxide and carbonate filler additives. Their properties are close to those of dentin, making them useful in restorative dentistry and endodontics. The aim of this study was to evaluate the in vitro biological effects of two such calcium silicate cements, Biodentine (BD) and Bioroot (BR), on dental stem cells in both direct and indirect contact models. The two models used aimed to mimic reparative dentin formation (direct contact) and reactionary dentin formation (indirect contact). An original aspect of this study is the use of an interposed thin agarose gel layer to assess the effects of diffusible components from the materials. Results The two biomaterials were compared and did not modify dental pulp stem cell (DPSC) proliferation. BD and BR showed no significant cytotoxicity, although some cell death occurred in direct contact. No apoptosis or inflammation induction was detected. A striking increase of mineralization induction was observed in the presence of BD and BR, and this effect was greater in direct contact. Surprisingly, biomineralization occurred even in the absence of mineralization medium. This differentiation was accompanied by expression of odontoblast-associated genes. Exposure by indirect contact did not stimulate the induction to such a level. Conclusion These two biomaterials both seem to be bioactive and biocompatible, preserving DPSC proliferation, migration and adhesion. The observed strong mineralization induction through direct contact highlights the potential of these biomaterials for clinical application in dentin-pulp complex regeneration. PMID:29370163

Eckols reduce dental pulp inflammation through the ERK1/2 pathway independent of COX-2 inhibition.

PubMed

Paudel, U; Lee, Y H; Kwon, T H; Park, N H; Yun, B S; Hwang, P H; Yi, H K

2014-11-01

The aim of this study was to elucidate the role of 6-6 bieckol (EB1) and pholorofucofuroeckol-A (EB5) from brown seaweed marine algae (Eisenia bicyclis) on lipopolysaccharide (LPS)-induced inflammation in human dental pulp cells (HDPCs). The cytotoxicity of EB1 and EB5 was examined by MTT assay on LPS-induced human dental pulp cells. Their role on expression of inflammatory, odontogenic, and osteogenic molecules was determined by Western blot analysis. The dentin mineralization was checked by alkaline phosphatase activity. The five compounds from E. bicyclis have different structure with non-cytotoxic in HDPCs. EB1 and EB5 showed anti-inflammatory properties and inhibited phosphorylated-extracellular signal-regulated kinase (p-ERK1/2) and phosphorylated-c-jun N-terminal kinases (p-JNK) without any cytotoxicity. In particular, EB1 inhibited cyclooxygenase-2 (COX-2) and p-ERK1/2 signaling, and EB5 inhibited only p-ERK1/2 signaling but not COX-2. Both compounds inhibited nuclear factor kappa-B (NF-κB) translocation. Furthermore, EB1 and EB5 increased dentinogenic and osteogenic molecules, and dentin mineralized via alkaline phosphatase activity (ALP) in LPS-induced HDPCs. This study elucidates that EB1 and EB5 have different types of anti-inflammatory property and help in dentin formation. Therefore, these compounds derived from marine algae of E. bicyclis may be used as selective therapeutic strategies for pulpitis and oral diseases. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Ionotropic P2X ATP Receptor Channels Mediate Purinergic Signaling in Mouse Odontoblasts.

PubMed

Shiozaki, Yuta; Sato, Masaki; Kimura, Maki; Sato, Toru; Tazaki, Masakazu; Shibukawa, Yoshiyuki

2017-01-01

ATP modulates various functions in the dental pulp cells, such as intercellular communication and neurotransmission between odontoblasts and neurons, proliferation of dental pulp cells, and odontoblast differentiation. However, functional expression patterns and their biophysical properties of ionotropic ATP (P2X) receptors (P2X 1 -P2X 7 ) in odontoblasts were still unclear. We examined these properties of P2X receptors in mouse odontoblasts by patch-clamp recordings. K + -ATP, nonselective P2X receptor agonist, induced inward currents in odontoblasts in a concentration-dependent manner. K + -ATP-induced currents were inhibited by P2X 4 and P2X 7 selective inhibitors (5-BDBD and KN62, respectively), while P2X 1 and P2X 3 inhibitors had no effects. P2X 7 selective agonist (BzATP) induced inward currents dose-dependently. We could not observe P2X 1, 2/3, 3 selective agonist (αβ-MeATP) induced currents. Amplitudes of K + -ATP-induced current were increased in solution without extracellular Ca 2+ , but decreased in Na + -free extracellular solution. In the absence of both of extracellular Na + and Ca 2+ , K + -ATP-induced currents were completely abolished. K + -ATP-induced Na + currents were inhibited by P2X 7 inhibitor, while the Ca 2+ currents were sensitive to P2X 4 inhibitor. These results indicated that odontoblasts functionally expressed P2X 4 and P2X 7 receptors, which might play an important role in detecting extracellular ATP following local dental pulp injury.

Clinical consequences of untreated dental caries assessed using PUFA index and its covariates in children residing in orphanages of Pakistan.

PubMed

Kamran, Ramsha; Farooq, Warda; Faisal, Mehreen Riaz; Jahangir, Faisal

2017-07-11

The purpose of this study was to determine the prevalence and clinical effects of untreated dental caries in Pakistani children residing in orphanages using the DMFT and PUFA index; association of decay and untreated dental caries with demographics including type of orphanage; behavioural and dental visiting pattern; and association of dental pain experience and type of orphanage with dental visiting. A cross-sectional survey was conducted on a total of 753 orphan children belonging to 4-17 years of age group residing in twin cities of Rawalpindi and Islamabad, Pakistan. Clinical examination of children was performed using the DMFT and PUFA index for the assessment of dental caries and untreated decay, followed by questionnaire enquiring about eating and oral hygiene habits, dental visiting pattern and dental pain and swelling experience. Association between dental decay, child's dental visiting and pain as a consequence of untreated decay was carried out using chi square test and logistic regression analysis. The overall caries prevalence was 34.8% and overall prevalence of PUFA/pufa was 15.9%. The mean score of DMFT and dmft was 1.18 (SD 0.39) and 1.04 (SD 0.23), and mean PUFA was 1.18 (SD 0.57) and mean pufa score 1.14 (SD 0.35). Untreated caries ratio was found to be 49.1% indicating half the decay had progressed to involve the pulp. No significant association of gender was found with DMFT, dmft, PUFA and pufa (p > 0.05), however, when analysed individually, the 'D' component of DMFT was significantly associated with male gender (p = 0.05). Furthermore, no significant association of DMFT/dmft or PUFA/pufa in either dentition was found with behavioural characteristics such as dietary and oral hygiene habits. Also, 66.2% children who experienced pain had not been to the dentist in the past year (p = 0.013) and 52.6% children who mentioned experiencing pain at night had not been to the dentist in the past year (p = 0.009). Children with decay were more likely to have visited the dentist (OR 3.3, 95% CI 1.42-7.6, p = 0.006). However, children who reported to have experienced pain were less likely to have visited the dentist in the past year (OR 0.53, 95% CI 0.32-0.88, p = 0.014). Moderate levels of decay were found in the sample with 'd' component majorly responsible for the cumulative DMFT index. However, alarmingly almost half of the decay component (49.1%) had progressed to involve the pulp. Experiencing pain in teeth prompted dental visits. Initiation of preventive services for children residing in orphanages in Pakistan would help greatly towards reducing the burden of untreated decay.

Dental disorders in brown howler monkeys (Alouatta guariba clamitans) maintained in captivity.

PubMed

Dias Neto, Ramiro das Neves; Fecchio, Roberto Silva; Rahal, Sheila Canevese; Teixeira, Carlos Roberto; Gioso, Marco Antônio; Pereira, Camila Trevisan; Santos, Maria Augusta Adami Pereira Dos; Milanelo, Liliane

2016-04-01

The aim of this study was to investigate dental disorders of brown howler monkeys maintained in captivity. The hypothesis is that the identification and diagnosis of the lesions may contribute to control and prevention. Sixteen intact brown howler monkeys (Alouatta guariba clamitans), eight females and eight males, weighing from 3.9 to 6.8 kg, were studied. Under general anesthesia, the teeth were evaluated by visual inspection, probing, palpation, and intra-oral radiographic exam. The findings were registered on a dental chart specific for primates. Of the 16 monkeys evaluated in the present study, 94% (n = 15) had some type of dental disorder. The lesions observed were dental calculus (88%), dental wear (81%), missing teeth (38%), gingivitis (19%), gingival recession (6%), dental fracture (19%), pulp exposure (19%), and dental staining (25%). Alouatta guariba clamitans maintained in captivity have a high rate of dental problems. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Direct measurement of time-dependent anesthetized in vivo human pulp temperature.

PubMed

Runnacles, Patrício; Arrais, Cesar Augusto Galvão; Pochapski, Marcia Thais; dos Santos, Fábio André; Coelho, Ulisses; Gomes, João Carlos; De Goes, Mário Fernando; Gomes, Osnara Maria Mongruel; Rueggeberg, Frederick Allen

2015-01-01

Human intrapupal tooth temperature is considered to be similar to that of the body (≈37 °C), although the actual temperature has never been measured. This study evaluated the in vivo, human, basal, coronal intrapulpal temperature of anesthetized upper first premolars. After approval of the local Ethics Committee was obtained (protocol no. 255,945), upper right and left first premolars requiring extraction for orthodontic reasons from 8 volunteers, ranging from 12 to 30 years old, received infiltrative and intraligamental anesthesia. The teeth (n=15) were isolated using rubber dam and a small, occlusal preparation was made using high-speed handpiece, under constant air-water spray, until a minute pulp exposure was attained. The sterile probe from a wireless, NIST-traceable, temperature acquisition system (Thermes WFI) was inserted directly into the coronal pulp. Once the probe was properly positioned and stable, real-time temperature data were continuously acquired for approximately 25 min. Data (°C) were subjected to 2-tailed, paired t-test (α=0.05), and the 95% confidence intervals for the initial and 25-min mean temperatures were also determined. The initial pulp temperature value (31.8±1.5 °C) was significantly lower than after 25-min (35.3±0.7 °C) (p<0.05). The 95% confidence interval for the initial temperature ranged from 31.0 to 32.6 °C and from 35.0 to 35.7 °C after 25 min. A slow, gradual temperature increase was observed after probe insertion until the pulp temperature reached a plateau, usually after 15 min. Consistent coronal, human, in vivo temperature values were observed and were slightly, but significantly below that of body core temperature. Copyright © 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

BACTERIAL PROFILE OF NECROTIC PULPS IN CHEETAH (ACINONYX JUBATUS) CANINE TEETH.

PubMed

Almansa Ruiz, José C; Bosman, Anna-Mari; Steenkamp, Gerhard

2016-03-01

The role of microbes and their antimicrobial susceptibilities in both acute and chronic infections of the dental pulp in humans has been well studied. Presently, no data are available on endodontic pathogens in cheetahs (Acinonyx jubatus). The aim of this study was to isolate and identify the bacteria found in the canine teeth of cheetahs, where the pulp was necrotic and exposed due to a complicated crown fracture. Thirty-six microbiologic samples were taken from root canals (RCs) of the canine teeth of 19 cheetahs: one pulp sample was taken from 10 cheetahs, four samples from 2 cheetahs, two samples from 3 cheetahs, and three samples from 4 cheetahs. Exposed pulps were cultured for aerobic and anaerobic bacteria; an additional screening with a 16S rRNA-specific polymerase chain reaction (PCR) was used for the last six samples. Antimicrobial susceptibility of isolates was determined by use of the Kirby-Bauer diffusion test. In total, 59 cultivable isolates belonging to 19 microbial species and 13 genera were recovered from the 36 RCs sampled. Only two samples yielded no cultivable bacteria. Thirty-two (54.49%) of the cultivable isolates were Gram positive and 27 (45.71%) were Gram negative. The maximum number of isolates cultivated from an individual RC was six. Facultative anaerobes (62.72%) were the most common bacteria of the RCs that yielded cultivable bacteria. Of the isolates, 28.81% were aerobic and 8.47% were strict anaerobes. The antimicrobials that showed the greatest efficacy in vitro against the different bacteria isolates were amikacin and gentamicin. The more common bacterial species isolated by PCR were anaerobes (60.8%), facultative anaerobes (30.2%), and aerobes (8.6%).

[Clinical observation of using composite resin to fill dental attrition on occlusal surface].

PubMed

Guo, Li-juan; Xu, Yan; Chen, Guang-quan

2005-10-01

The purpose of this study was to evaluate the clinical effect of using composite resin to fill dental attrition on occlusal surface. Whether the dental attrition had enough space to the material was determined first. Sometimes grinding the sharp and steep cusps or ridges of the opposite teeth was needed. Then the dental attrition was cleaned thoroughly, and finally filled with CLEARFIL bond and composite resin without preparing cavity. The follow-up period was 1 year. Out of 70 teeth from 25 patients, 52 were successful, 16 were curative, and 2 were failed. The curative rate was 97.14%. The method avoids endangering the dental pulp. It was easily accepted by the patients and operated by dentists, and can be widely applied in clinical cases.

Human periapical cyst-mesenchymal stem cells differentiate into neuronal cells.

PubMed

Marrelli, M; Paduano, F; Tatullo, M

2015-06-01

It was recently reported that human periapical cysts (hPCys), a commonly occurring odontogenic cystic lesion of inflammatory origin, contain mesenchymal stem cells (MSCs) with the capacity for self-renewal and multilineage differentiation. In this study, periapical inflammatory cysts were compared with dental pulp to determine whether this tissue may be an alternative accessible tissue source of MSCs that retain the potential for neurogenic differentiation. Flow cytometry and immunofluorescence analysis indicated that hPCy-MSCs and dental pulp stem cells spontaneously expressed the neuron-specific protein β-III tubulin and the neural stem-/astrocyte-specific protein glial fibrillary acidic protein (GFAP) in their basal state before differentiation occurs. Furthermore, undifferentiated hPCy-MSCs showed a higher expression of transcripts for neuronal markers (β-III tubulin, NF-M, MAP2) and neural-related transcription factors (MSX-1, Foxa2, En-1) as compared with dental pulp stem cells. After exposure to neurogenic differentiation conditions (neural media containing epidermal growth factor [EGF], basic fibroblast growth factor [bFGF], and retinoic acid), the hPCy-MSCs showed enhanced expression of β-III tubulin and GFAP proteins, as well as increased expression of neurofilaments medium, neurofilaments heavy, and neuron-specific enolase at the transcript level. In addition, neurally differentiated hPCy-MSCs showed upregulated expression of the neural transcription factors Pitx3, Foxa2, Nurr1, and the dopamine-related genes tyrosine hydroxylase and dopamine transporter. The present study demonstrated for the first time that hPCy-MSCs have a predisposition toward the neural phenotype that is increased when exposed to neural differentiation cues, based on upregulation of a comprehensive set of proteins and genes that define neuronal cells. In conclusion, these results provide evidence that hPCy-MSCs might be another optimal source of neural/glial cells for cell-based therapies to treat neurologic diseases. © International & American Associations for Dental Research 2015.

Cellular Responses in Human Dental Pulp Stem Cells Treated with Three Endodontic Materials

PubMed Central

Ibañez-Cabellos, José Santiago; de Cutanda, Sergio Bañuls-Sánchez; Berenguer-Pascual, Ester; Beltrán-García, Jesús; García-López, Eva; Pallardó, Federico V.; García-Giménez, José Luis; Pallarés-Sabater, Antonio; Zarzosa-López, Ignacio; Monterde, Manuel

2017-01-01

Human dental pulp stem cells (HDPSCs) are of special relevance in future regenerative dental therapies. Characterizing cytotoxicity and genotoxicity produced by endodontic materials is required to evaluate the potential for regeneration of injured tissues in future strategies combining regenerative and root canal therapies. This study explores the cytotoxicity and genotoxicity mediated by oxidative stress of three endodontic materials that are widely used on HDPSCs: a mineral trioxide aggregate (MTA-Angelus white), an epoxy resin sealant (AH-Plus cement), and an MTA-based cement sealer (MTA-Fillapex). Cell viability and cell death rate were assessed by flow cytometry. Oxidative stress was measured by OxyBlot. Levels of antioxidant enzymes were evaluated by Western blot. Genotoxicity was studied by quantifying the expression levels of DNA damage sensors such as ATM and RAD53 genes and DNA damage repair sensors such as RAD51 and PARP-1. Results indicate that AH-Plus increased apoptosis, oxidative stress, and genotoxicity markers in HDPSCs. MTA-Fillapex was the most cytotoxic oxidative stress inductor and genotoxic material for HDPSCs at longer times in preincubated cell culture medium, and MTA-Angelus was less cytotoxic and genotoxic than AH-Plus and MTA-Fillapex at all times assayed. PMID:28751918

Effects and Effectiveness of Cavity Disinfectants in Operative Dentistry: A Literature Review.

PubMed

Bin-Shuwaish, Mohammed S

2016-10-01

The degree of success in the elimination of bacteria during cavity preparation and prior to the insertion of a restoration may increase the longevity of the restoration and therefore the success of the restorative procedure. The complete eradication of bacteria in a caries-affected tooth, during cavity preparation, is considered a difficult clinical task. In addition to weakening the tooth structure, attempts to excavate extensive carious tissue completely, by only mechanical procedures, may affect the vitality of the pulp. Therefore, disinfection of the cavity preparation after caries excavation can aid in the elimination of bacterial remnants that can be responsible for recurrent caries, postoperative sensitivity, and failure of the restoration. However, the effects of disinfectants on the restorative treatment have been a major concern for dental clinicians and researchers. This review aims to explore existing literature and provide information about different materials and techniques that have been used for disinfecting cavity preparations and their effects and effectiveness in operative dentistry and, therefore, helps dental practitioners with clinical decision to use cavity disinfectants during restorative procedures. Antimicrobial effectiveness and effects on the pulp and dental restorations, in addition to possible side effects, were all reviewed in this paper.

Heat generated by Er:YAG laser in the pulp chamber of teeth submitted to removal of dental tissue and composite resin

NASA Astrophysics Data System (ADS)

Zanin, Fatima; Brugnera, Aldo, Jr.; Pecora, Jesus D.; Pinheiro, Antonio; Spano, Julio; Barbin, Eduardo; Marchesan, Melissa A.

2004-05-01

The knowledge about and control of thermal energy produced by Er:YAG laser after irradiating hard dental tissues and compound resin is important because the pulp, like all vital biological tissue, has a certain capacity for supporting stimulus. The objective of this study was to analyze the thermal variation generated by Er:YAG laser (λ=2.94μm) during the preparation of a Class I cavity in the dental structure and in the removal of microhybrid Z100 (3M) compound resin. An evaluation was made of 30 maxillary human pre-molar teeth from the bank of the Endodontic Laboratory Center of Ribeirao Preto Dental School, Brasil. The sample was divided into 6 groups of 5 teeth each: Group 1, preparation of Class I cavity with Er:YAG laser (350mJ, 3Hz, 343 impulses, 120J, 113 seconds); Group 2, preparation of Class I cavity with Er:YAG laser (350mJ, 4Hz, 343 impulses, 120J, 81 seconds); Group 3, preparation of Class I cavity with Er:YAG laser (350mJ, 6Hz, 343 impulses, 120J, 58 seconds); Group 4, removal of compound resin from Class I preparation with Er:YAG laser (350mJ, 3Hz, 258 impulses, 90J, 85 seconds); Group 5, removal of compound resin from Class I preparation with Er:YAG laser (350mJ, 4Hz, 258 impulses, 90J, 67 seconds); Group 6, removal of compound resin from Class I preparation with Er:YAG laser (350mJ, 6Hz, 258 impulses, 42 seconds). The laser used was KaVo Key 2 (Biberach, Germany), λ=2,94μm, P=3 Watts, pulse duration of 250μs, with air-water cooling. The increase in temperature during dental preparation and the removal of the compound resin was evaluated by means of a Tektronix DMM916 Thermocouple (Consitec, Brasil). The results showed that the application of laser for the removal of the hard dental tissues and for the removal of compound resins with the pulse frequencies 3, 4 and 6 Hz did not generate heating greater than 3.1°C and remained within the histopathological limits permitted for pulp tissue (5.5°C) and there was a significant statistical difference between the heat generated by the application of laser in the removal of the hard dental tissues and in the removal of compound resins (p<0.01). The average increase in temperature of the compound resin component was greater than the tooth.

The diagnosis and conservative treatment of a complex type 3 dens invaginatus using cone beam computed tomography (CBCT) and 3D plastic models.

PubMed

Kfir, A; Telishevsky-Strauss, Y; Leitner, A; Metzger, Z

2013-03-01

To investigate the use of 3D plastic models, printed from cone beam computed tomography (CBCT) data, for accurate diagnosis and conservative treatment of a complex case of dens invaginatus. A chronic apical abscess with a draining sinus tract was diagnosed during the treatment planning stage of orthodontic therapy. Radiographic examination revealed a large radiolucent area associated with an invaginated right maxillary central incisor, which was found to contain a vital pulp. The affected tooth was strategic in the dental arch. Conventional periapical radiographs provided only partial information about the invagination and its relationship with the main root canal and with the periapical tissues. A limited-volume CBCT scan of the maxilla did not show evidence of communication between the infected invagination and the pulp in the main root canal, which could explain the pulp vitality. A novel method was adopted to allow for instrumentation, disinfection and filling of the invagination, without compromising the vitality of the pulp in the complex root canal system. The CBCT data were used to produce precise 3D plastic models of the tooth. These models facilitated the treatment planning process and the trial of treatment approaches. This approach allowed the vitality of the pulp to be maintained in the complex root canal space of the main root canal whilst enabling the healing of the periapical tissues. Even when extensive periapical pathosis is associated with a tooth with type III dens invaginatus, pulp sensibility tests should be performed. CBCT is a diagnostic tool that may allow for the management of such teeth with complex anatomy. 3D printed plastic models may be a valuable aid in the process of assessing and planning effective treatment modalities and practicing them ex vivo before actually performing the clinical procedure. Unconventional technological approaches may be required for detailed treatment planning of complex cases of dens invaginatus. © 2012 International Endodontic Journal. Published by Blackwell Publishing Ltd.

Current overview on challenges in regenerative endodontics

PubMed Central

Bansal, Ramta; Jain, Aditya; Mittal, Sunandan

2015-01-01

Introduction: Regenerative endodontics provides hope of converting the non-vital tooth into vital once again. It focuses on substituting traumatized and pathological pulp with functional pulp tissue. Current regenerative procedures successfully produce root development but still fail to re-establish real pulp tissue and give unpredictable results. There are several drawbacks that need to be addressed to improve the quality and efficiency of the treatment. Aim: The aim of this review article is to discuss major priorities that ought to be dealt before applications of regenerative endodontics flourish the clinical practice. Materials and Methods: A web-based research on MEDLINE was done using filter terms Review, published in the last 10 years and Dental journals. Keywords used for research were “regenerative endodontics,” “dental stem cells,” “growth factor regeneration,” “scaffolds,” and “challenges in regeneration.” This review article screened about 150 articles and then the relevant information was compiled. Results: Inspite of the impressive growth in regenerative endodontic field, there are certain loopholes in the existing treatment protocols that might sometimes result in undesired and unpredictable outcomes. Conclusion: Considerable research and development efforts are required to improve and update existing regenerative endodontic strategies to make it an effective, safe, and biological mode to save teeth. PMID:25657518

Immunohistochemical expression of heat shock protein27 in the mouse dental pulp after immediate teeth separation

PubMed Central

2011-01-01

Aim After immediate teeth separation, expression of HSP27 in the mouse dental pulp was examined. Immunohistochemistry was performed to examine the incidence of HSP27 expression. Materials and methods A total of 36 8-week-old ddY mice were used as experimental subjects and a wedge was inserted in between maxillary right molars. The wedge was removed 30 min or 3 h after insertion. Animals were immediately sacrificed after the removal of wedge or until 1 week later and serial sections from paraffin-embedded tissues were prepared. Immunohistochemistry was carried out to examine the expression of HSP27. The untreated side served as the control. Results In the control group, the endothelial cells and some pulp fibroblasts weakly expressed HSP27 suggesting that the expression is due to mechanical stress brought about by physiological masticatory force and pressure from the tongue. In both 30 min and 3 h experimental groups, HSP27 expression was highest at 24 h after wedge removal and the expression remained the same or started to decrease thereafter. The expression decreased at the same level as that of the control group 1 week after wedge removal. Conclusion HSP27 may serve as an indicator of stimulus strong enough to show its expression. PMID:22027643

Conservative approach of a symptomatic carious immature permanent tooth using a tricalcium silicate cement (Biodentine): a case report

PubMed Central

Grosgogeat, Brigitte; Seux, Dominique; Farge, Pierre

2013-01-01

The restorative management of deep carious lesions and the preservation of pulp vitality of immature teeth present real challenges for dental practitioners. New tricalcium silicate cements are of interest in the treatment of such cases. This case describes the immediate management and the follow-up of an extensive carious lesion on an immature second right mandibular premolar. Following anesthesia and rubber dam isolation, the carious lesion was removed and a partial pulpotomy was performed. After obtaining hemostasis, the exposed pulp was covered with a tricalcium silicate cement (Biodentine, Septodont) and a glass ionomer cement (Fuji IX extra, GC Corp.) restoration was placed over the tricalcium silicate cement. A review appointment was arranged after seven days, where the tooth was asymptomatic with the patient reporting no pain during the intervening period. At both 3 and 6 mon follow up, it was noted that the tooth was vital, with normal responses to thermal tests. Radiographic examination of the tooth indicated dentin-bridge formation in the pulp chamber and the continuous root formation. This case report demonstrates a fast tissue response both at the pulpal and root dentin level. The use of tricalcium silicate cement should be considered as a conservative intervention in the treatment of symptomatic immature teeth. PMID:24303363

Pulp temperature increase during photo-activated disinfection (PAD) of periodontal pockets: an in vitro study.

PubMed

El Yazami, H; Zeinoun, Toni; Bou Saba, S; Lamard, L; Peremans, A; Limme, M; Geerts, S; Lamy, M; Nammour, S

2010-09-01

The capacity of photo-sensitizers, used in combination with laser light to kill micro-organisms has been demonstrated in different studies. Photo-activated disinfection (PAD) has been introduced in periodontology as an aid for disinfection of periodontal pockets. The aim of this study is to verify the harm for dental vitality of the use of PAD in periodontal pockets. Root canals of 24 freshly extracted human teeth where prepared using profiles up to a size of ISO #50 and filled with thermo-conductor paste. A silicon-based false gum was made in which a periodontal pocket was created and filled with photo-sensitizer phenothiazine chloride (phenothiazine-5-ium, 3.7-bis (dimethylamino)-, chloride). The external root surface was irradiated during 60 s with a 660-nm diode laser (output power: 20 mW; power density: 0.090 W/cm(2); Energy density: 5.46 J/cm(2)) using a periodontal tip with a diameter of 1 mm and a length of 7 mm. Temperatures were recorded inside the root canal using a thermocouple. Measurements were recorded every second, starting at 10 s before lasering, during the irradiation and were continued for 150 s after the end of irradiation, and six measurements were done per tooth. An average temperature increase of 0.48 +/- 0.11 degrees C was recorded. Our results demonstrated that pulp temperature increase was lower than 3 degrees C, which is considered to be harmless for pulp injury. Regarding pulp temperature increase, the use of PAD for disinfection of periodontal pockets can be considered as a safe procedure for dental vitality.

Pulp Inflammation Diagnosis from Clinical to Inflammatory Mediators: A Systematic Review.

PubMed

Zanini, Marjorie; Meyer, Elisabeth; Simon, Stéphane

2017-07-01

Similar to other tissues, the dental pulp mounts an inflammatory reaction as a way to eliminate pathogens and stimulate repair. Pulp inflammation is prerequisite for dentin pulp complex repair and regeneration; otherwise, chronic disease or pulp necrosis occurs. Evaluation of pulp inflammation severity is necessary to predict the clinical success of maintaining pulp vitality. Clinical limitations to evaluating in situ inflammatory status are well-described. A molecular approach that aids clinical distinction between reversible and irreversible pulpitis could improve the success rate of vital pulp therapy. The aim of this article is to review inflammatory mediator expression in the context of clinical diagnosis. We searched PubMed and Cochrane databases for articles published between 1970 and December 2016. Only published studies of inflammatory mediator expression related to clinical diagnosis were eligible for inclusion and analysis. Thirty-two articles were analyzed. Two molecular approaches were described by study methods, protein expression analysis and gene expression analysis. Our review indicates that interleukin-8, matrix metalloproteinase 9, tumor necrosis factor-α, and receptor for advanced glycation end products expression increase at both the gene and protein levels during inflammation. Clinical irreversible pulpitis is related to specific levels of inflammatory mediator expression. The difference in expression between reversible and irreversible disease is both quantitative and qualitative. On the basis of our analysis, in situ quantification of inflammatory mediators may aid in the clinical distinction between reversible and irreversible pulpitis. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Measuring the impact of practice-based research networks on member dentists in the Collaboration on Networked Dental and Oral Health Research, CONDOR.

PubMed

McBride, Ruth; Leroux, Brian; Lindblad, Anne; Williams, O Dale; Lehmann, Maryann; Rindal, D Brad; Botello-Harbaum, Maria; Gilbert, Gregg H; Gillette, Jane; Demko, Catherine

2013-05-01

The National Institute of Dental and Craniofacial Research funded three practice-based research networks (PBRNs), NW-PRECEDENT, PEARL and DPBRN to conduct studies relevant to practicing general dentists. These PBRNs collaborated to develop a questionnaire to assess the impact of network participation on changes in practice patterns. This report presents results from the initial administration of the questionnaire. Questionnaires were administered to network dentists and a non-network reference group. Practice patterns including caries diagnosis and treatment, pulp cap materials, third molar extraction, dentine hypersensitivity treatments and endodontic treatment and restoration were assessed by network, years in practice, and level of network participation. Test-retest reliability of the questionnaire was evaluated. 950 practitioners completed the questionnaire. Test-retest reliability was good-excellent (kappa>0.4) for most questions. Significant differences in responses by network were not observed. The use of caries risk assessment forms differed by both network participation (p<0.001) and years since dental degree (p=0.026). Recent dental graduates are more likely to recommend third molar removal for preventive reasons (p=0.003). Practitioners in the CONDOR research networks are similar to their US colleagues. As a group, however, these practitioners show a more evidence-based approach to their practice. Dental PBRNs have the potential to improve the translation of evidence into daily practice. Designing methods to assess practice change and the associated factors is essential to addressing this important issue. Copyright © 2013 Elsevier Ltd. All rights reserved.

Comparison of osteo/odontogenic differentiation of human adult dental pulp stem cells and stem cells from apical papilla in the presence of platelet lysate.

PubMed

Abuarqoub, Duaa; Awidi, Abdalla; Abuharfeil, Nizar

2015-10-01

Human dental pulp cells (DPSCs) and stem cells from apical papilla have been used for the repair of damaged tooth tissues. Human platelet lysate (PL) has been suggested as a substitute for fetal bovine serum (FBS) for large scale expansion of dental stem cells. However, biological effects and optimal concentrations of PL for proliferation and differentiation of human dental stem cells remain to be elucidated. DPSCs and SCAP cells were isolated from impacted third molars of young healthy donors, at the stage of root development and identified by markers using flow cytometry. For comparison the cells were cultured in media containing PL (1%, 5% and 10%) and FBS, with subsequent induction for osteogenic/odontogenic differentiation. The cultures were analyzed for; morphology, growth characteristics, mineralization potential (Alizarin Red method) and differentiation markers using ELISA and real time -polymerase chain reaction (qPCR). The proliferation rates of DPSCs and SCAP significantly increased when cells were treated with 5% PL (7X doubling time) as compared to FBS. 5% PL also enhanced mineralized differentiation of DPSCs and SCAP, as indicated by the measurement of alkaline phosphatase activity, osteocalcin and osteopontin, calcium deposition and q-PCR. Our findings suggest that using 5% platelet lysate, proliferation and osteo/odontogenesis of DPSCs and SCAP for a short period of time (15 days), was significantly improved. This may imply its use as an optimum concentration for expansion of dental stem cells in bone regeneration. Copyright © 2015 Elsevier Ltd. All rights reserved.

Viability of imaging structures inside human dentin using dental transillumination

NASA Astrophysics Data System (ADS)

Grandisoli, C. L.; Alves-de-Souza, F. D.; Costa, M. M.; Castro, L.; Ana, P. A.; Zezell, D. M.; Lins, E. C.

2014-02-01

Dental Transillumination (DT) is a technique for imaging internal structures of teeth by detecting infrared radiation transmitted throughout the specimens. It was successfully used to detect caries even considering dental enamel and dentin scatter infrared radiation strongly. Literature reports enamel's scattering coefficient is 10 to 30 times lower than dentin; this explain why DT is useful for imaging pathologies in dental enamel, but does not disable its using for imaging dental structures or pathologies inside the dentin. There was no conclusive data in the literature about the limitations of using DT to access biomedical information of dentin. The goal in this study was to present an application of DT to imaging internal structures of dentin. Slices of tooth were confectioned varying the thickness of groups from 0.5 mm up to 2,5 mm. For imaging a FPA InGaAs camera Xeva 1.7- 320 (900-1700 nm; Xenics, Inc., Belgium) and a 3W lamp-based broadband light source (Ocean Optics, Inc., USA) was used; bandpass optical filters at 1000+/-10 nm, 1100+/-10 nm, 1200+/-10 nm and 1300+/-50 nm spectral region were also applied to spectral selection. Images were captured for different camera exposure times and finally a computational processing was applied. The best results revealed the viability to imaging dent in tissue with thickness up to 2,5 mm without a filter (900-1700nm spectral range). After these results a pilot experiment of using DT to detect the pulp chamber of an incisive human tooth was made. New data showed the viability to imaging the pulp chamber of specimen.

Matrix-assisted laser desorption/ionization imaging mass spectrometry revealed traces of dental problem associated with dental structure.

PubMed

Hirano, Hirokazu; Masaki, Noritaka; Hayasaka, Takahiro; Watanabe, Yoshiko; Masumoto, Kazuma; Nagata, Tetsuji; Katou, Fuminori; Setou, Mitsutoshi

2014-02-01

Periodontal disease is a serious dental problem because it does not heal naturally and leads to tooth loss. In periodontal disease, inflammation at periodontal tissue is thought as predominant, and its effect against tooth itself remains unclear. In this study, we applied matrix-assisted laser desorption/ionization imaging mass spectrometry (IMS) to teeth for the first time. By comparing anatomical structure of tooth affected with periodontal disease with normal ones, we analyzed traces of the disease on tooth. We found signals characteristic of enamel, dentin, and dental pulp, respectively, in mass spectra obtained from normal teeth. Ion images reconstructed using these signals showed anatomical structures of the tooth clearly. Next, we performed IMS upon teeth of periodontal disease. Overall characteristic of the mass spectrum appeared similar to normal ones. However, ion images reconstructed using signals from the tooth of periodontal disease revealed loss of periodontal ligament visualized together with dental pulp in normal teeth. Moreover, ion image clearly depicted an accumulation of signal at m/z 496.3 at root surface. Such an accumulation that cannot be examined only from mass spectrum was revealed by utilization of IMS. Recent studies about inflammation revealed that the signal at m/z 496.3 reflects lyso-phosphatidylcholine (LPC). Infiltration of the signal is statistically significant, and its intensity profile exhibited the influence has reached deeply into the tooth. This suggests that influence of periodontal disease is not only inflammation of periodontal tissue but also infiltration of LPC to root surface, and therefore, anti-inflammatory treatment is required besides conventional treatments.

Pulp regeneration concepts for non-vital teeth: from tissue engineering to clinical approaches.

PubMed

Orti, Valérie; Collart-Dutilleul, Pierre-Yves; Piglionico, Sofía Silvia; Pall, Orsolya; Cuisinier, Frédéric; Panayotov, Ivan Vladislavov

2018-05-04

Following the basis of tissue engineering (Cells - Scaffold - Bioactive molecules), regenerative endodontic has emerged as a new concept of dental treatment. Clinical procedures have been proposed by endodontic practitioners willing to promote regenerative therapy. Preserving pulp vitality was a first approach. Later procedures aimed to regenerate a vascularized pulp in necrotic root canals. However, there is still no protocol allowing an effective regeneration of necrotic pulp tissue either in immature or mature teeth. This review explore in vitro and preclinical concepts developed during the last decade, especially the potential use of stem cells, bioactive molecules and scaffolds, and makes a comparison with the goals achieved so far in clinical practice. Regeneration of pulp-like tissue has been shown in various experimental conditions. However, the appropriate techniques are currently in a developmental stage. The ideal combination of scaffolds and growth factors to obtain a complete regeneration of the pulp-dentin complex is still unknown. The use of stem cells, especially from pulp origin, sounds promising for pulp regeneration therapy, but it has not been applied so far for clinical endodontics, in case of necrotic teeth. The gap observed between the hope raised from in vitro experiments and the reality of endodontic treatments suggests that clinical success may be achieved without external stem cell application. Therefore, procedures using the concept of cell homing, through evoked bleeding, that permit to recreate a living tissue that mimics the original pulp have been proposed. Perspectives for pulp tissue engineering in a near future include a better control of clinical parameters and pragmatic approach of the experimental results (autologous stem cells from cell homing, controlled release of growth factors). In the coming years, this therapeutic strategy will probably become a clinical reality, even for mature necrotic teeth.

The influences of N-acetyl cysteine (NAC) on the cytotoxicity and mechanical properties of Poly-methylmethacrylate (PMMA)-based dental resin

PubMed Central

Jiao, Yang; Ma, Sai; Li, Jing; Shan, Lequn; Yang, Yanwei; Li, Meng

2015-01-01

Objectives. This study aimed to investigate the influences of N-acetyl cysteine (NAC) on cytotoxicity and mechanical properties of Poly-methylmethacrylate (PMMA) dental resins. Methods. Experimental PMMA resin was prepared by incorporating various concentrations of NAC (0, 0.15, 0.3, 0.6 and 0.9 wt.%). MTT assay was performed to investigate viability of human dental pulp cells after exposure to extract of PMMA resin with or without NAC. Cell adhesion on resin specimens was examined with scanning electron microscopy. Degree of conversion was studied with Fourier Transform Infrared Spectroscopy (FTIR). Flexural strength, microhardness and surface roughness was evaluated using a universal testing machine, microhardness tester and optical profilometer, respectively. Results. Incorporation of NAC into PMMA resin significantly reduced its cytotoxicity and enhanced cell adhesion on its surface. NAC induced negative influences on the mechanical and physical properties of PMMA resin in a dose-dependent manner. The degree of conversion for all experimental PMMA resins reached as high as 72% after 24 h of polymerization. All the tested properties were maintained when the concentration of incorporated NAC was 0.15 wt.%. Conclusion. The addition of 0.15 wt.% NAC remarkably improved biocompatibility of PMMA resin without exerting significant negative influence on its mechanical and physical properties. PMID:25922788

Median mental sinus in twins.

PubMed

Ong, S T; Ngeow, W C

1999-05-01

Sinus on the chin can be the result of a chronic apical abscess due to pulp necrosis of a mandibular anterior tooth. The tooth is usually asymptomatic, and a dental cause is therefore not apparent to the patient or the unsuspecting clinician. Not infrequently, the patient may seek treatment from a dermatologist or general surgeon instead of a dentist. Excision and repair of the fistula may be carried out with subsequent breakdown because the dental pathology is not removed. This paper reports the presence of median mental sinus of dental origin in twins. One case healed following root canal therapy while the other required both root canal therapy and surgery to eliminate the infection.

Immunocytochemical investigation of immune cells within human primary and permanent tooth pulp.

PubMed

Rodd, H D; Boissonade, F M

2006-01-01

The aim of this study was to determine whether there are any differences in the number and distribution of immune cells within human primary and permanent tooth pulp, both in health and disease. The research took the form of a quantitative immunocytochemical study. One hundred and twenty-four mandibular first permanent molars and second primary molars were obtained from children requiring dental extractions under general anaesthesia. Following exodontia, 10-microm-thick frozen pulp sections were processed for indirect immunofluorescence. Triple-labelling regimes were employed using combinations of the following: (1) protein gene product 9.5, a general neuronal marker; (2) leucocyte common antigen (LCA); and (3) Ulex europaeus I lectin, a marker of vascular endothelium. Image analysis was then used to determine the percentage area of immunostaining for LCA. Leucocytes were significantly more abundant in the pulp horn and mid-coronal region of intact and carious primary teeth, as compared to permanent teeth (P < 0.05, anova). Both dentitions demonstrated the presence of well-localized inflammatory cell infiltrates and marked aborization of pulpal nerves in areas of dense leucocyte accumulation. Primary and permanent tooth pulps appear to have a similar potential to mount inflammatory responses to gross caries The management of the compromised primary tooth pulp needs to be reappraised in the light of these findings.

Pulpal safety of a 9.6-μm TEA CO2 laser used for caries prevention

NASA Astrophysics Data System (ADS)

Goodis, Harold E.; Fried, Daniel; Featherstone, John D. B.

2002-06-01

Lasers are used for several procedures involving hard and soft tissues of the oral cavity. Included in those procedures is the use of the CO2 laser to alter the surface structure of tooth enamel to render it more resistant to caries. A new 9.6micrometers wavelength TEA CO2 laser (Argu Photonics, Jpiter, FL) has been investigated as a device that can be used for this procedure without harming the dental pulp. Erupted, caries and restoration free third molars (n=24) were used in the experiment. Teeth were irradiated at an incident fluence of 1.5J/cm2 and a repetition rate of 10Hz and a spot size 1mm in diameter. At the low and high settings, 200 to 400 pulses were delivered at 12mJ per pulse for a total energy of 2.4 or 4.8J delivered for 20 or 40 seconds respectively. Other teeth were subjected to a sham dental procedure (positive control) or no procedure (negative control). Prior to testing, radiographs were taken of all teeth, and they were tested pulpally using heat, cold and electricity to determine vitality. The teeth were removed either immediately or at one week or one month after testing. They were bioprepared and examined histologically for signs of inflammation. Only one tooth developed symptoms of sensitivity to cold for 10 days following exposure to the high power level. The sensitivity was of fleeting duration and was judged to be reversible pulpitis. All teeth tested responded normally at pretesting and pre-extraction time periods. Histological examination disclosed no indication of an inflammatory response in the pulp tissue. All sections appeared normal with no changes seen in the normal pulpal morphology. We conclude that the 9.6 micrometers wavelength laser causes no pulpal damage at the energy levels used and can be used safely for caries prevention treatments.

Doxycycline-Encapsulated Nanotube-Modified Dentin Adhesives

PubMed Central

Feitosa, S.A.; Palasuk, J.; Kamocki, K.; Geraldeli, S.; Gregory, R.L.; Platt, J.A.; Windsor, L.J.; Bottino, M.C.

2014-01-01

This article presents details of fabrication, biological activity (i.e., anti–matrix metalloproteinase [anti-MMP] inhibition), cytocompatibility, and bonding characteristics to dentin of a unique doxycycline (DOX)–encapsulated halloysite nanotube (HNT)–modified adhesive. We tested the hypothesis that the release of DOX from the DOX-encapsulated nanotube-modified adhesive can effectively inhibit MMP activity. We incorporated nanotubes, encapsulated or not with DOX, into the adhesive resin of a commercially available bonding system (Scotchbond Multi-Purpose [SBMP]). The following groups were tested: unmodified SBMP (control), SBMP with nanotubes (HNT), and DOX-encapsulated nanotube-modified adhesive (HNT+DOX). Changes in degree of conversion (DC) and microtensile bond strength were evaluated. Cytotoxicity was examined on human dental pulp stem cells (hDPSCs). To prove the successful encapsulation of DOX within the adhesives—but, more important, to support the hypothesis that the HNT+DOX adhesive would release DOX at subantimicrobial levels—we tested the antimicrobial activity of synthesized adhesives and the DOX-containing eluates against Streptococcus mutans through agar diffusion assays. Anti-MMP properties were assessed via β-casein cleavage assays. Increasing curing times (10, 20, 40 sec) led to increased DC values. There were no statistically significant differences (p > .05) in DC within each increasing curing time between the modified adhesives compared to SBMP. No statistically significant differences in microtensile bond strength were noted. None of the adhesives eluates were cytotoxic to the human dental pulp stem cells. A significant growth inhibition of S. mutans by direct contact illustrates successful encapsulation of DOX into the experimental adhesive. More important, DOX-containing eluates promoted inhibition of MMP-1 activity when compared to the control. Collectively, our findings provide a solid background for further testing of encapsulated MMP inhibitors into the synthesis of therapeutic adhesives that may enhance the longevity of hybrid layers and the overall clinical performance of adhesively bonded resin composite restorations. PMID:25201918

Dental management of patient with Williams Syndrome - A case report.

PubMed

Wong, Daniel; Ramachandra, Srinivas Sulugodu; Singh, Ashish Kumar

2015-01-01

Williams syndrome is a multisystemic rare genetic disorder caused by deletion of 26-28 genes in the long arm of chromosome 7. It is characterized by developmental and physical abnormalities including congenital cardiovascular abnormalities, mental retardation, neurological features, growth deficiency, genitourinary manifestations, gastrointestinal problems, musculoskeletal problems, unique behavioral characteristics, and dental problems. Dental abnormalities include malocclusion, hypodontia, malformed teeth, taurodontism, pulp stones, increased space between teeth, enamel hypoplasia, and high prevalence of dental caries. Authors report a 17-year-old female patient with underlying Williams syndrome. Oral features and problems seen in the patient are listed. Malocclusion and screwdriver shaped teeth were noticed. Generalized widening of the periodontal ligament space with vital teeth was seen. This finding has not been reported in cases of Williams syndrome earlier. Precautions taken during dental treatment in patients with Williams syndrome are also discussed.

The chronology of the radiographic visibility of the periodontal ligament and the root pulp in the lower third molars.

PubMed

Timme, M; Timme, W H; Olze, A; Ottow, C; Ribbecke, S; Pfeiffer, H; Dettmeyer, R; Schmeling, A

2017-07-01

Eruption and mineralization of third molars are the main criteria for dental age estimation in living adolescents. As the validation of completion of the 18th year of life appears not to be possible with the forensically necessary probability even if all the third molars of a person are completely mineralized, degenerative dental characteristics might be used for this purpose. In previous publications by Olze et al. (2010a,b) the radiographic visibility of the periodontal ligament and the root pulp in lower third molars were suggested as methods for this purpose. The aim of this study was to validate these characteristics in a large study population with a wide age range. In a material of 2346 orthopantomograms of 1167 female and 1179 male Germans aged from 15 to 70years the radiographic visibility of the root pulp in the lower third molars with completed mineralization were studied according to stage classifications proposed by Olze et al. (2010a,b). 1541 orthopantomograms of 705 females and 836 males with a sufficient quality of the radiograph showed at least one third molar. The suitability of the studied characteristics for age estimation in living individuals could be confirmed. Males and females presenting stage 1 of both characteristics were older than 18years of life. Males and females presenting stage 2 of both characteristics were older than 21years of life. The high number of missing third molars in the studied age group (46-60%) must be considered as a limitation of the methods. In further studies the influence of ethnicity, dietary habits and modern dental health care on the characteristics in question should be investigated. Copyright © 2017 The Chartered Society of Forensic Sciences. Published by Elsevier B.V. All rights reserved.

Odontogenic Differentiation of Human Dental Pulp Stem Cells on Hydrogel Scaffolds Derived from Decellularized Bone Extracellular Matrix and Collagen Type I.

PubMed

Paduano, Francesco; Marrelli, Massimo; White, Lisa J; Shakesheff, Kevin M; Tatullo, Marco

2016-01-01

The aim of this study was to evaluate the level of odontogenic differentiation of dental pulp stem cells (DPSCs) on hydrogel scaffolds derived from bone extracellular matrix (bECM) in comparison to those seeded on collagen I (Col-I), one of the main components of dental pulp ECM. DPSCs isolated from human third molars were characterized for surface marker expression and odontogenic potential prior to seeding into bECM or Col-I hydrogel scaffolds. The cells were then seeded onto bECM and Col-I hydrogel scaffolds and cultured under basal conditions or with odontogenic and growth factor (GF) supplements. DPSCs cultivated on tissue culture polystyrene (TCPS) with and without supplements were used as controls. Gene expression of dentin sialophosphoprotein (DSPP), dentin matrix protein 1 (DMP-1) and matrix extracellular phosphoglycoprotein (MEPE) was evaluated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and mineral deposition was observed by Von Kossa staining. When DPSCs were cultured on bECM hydrogels, the mRNA expression levels of DSPP, DMP-1 and MEPE genes were significantly upregulated with respect to those cultured on Col-I scaffolds or TCPS in the absence of extra odontogenic inducers. In addition, more mineral deposition was observed on bECM hydrogel scaffolds as demonstrated by Von Kossa staining. Moreover, DSPP, DMP-1 and MEPE mRNA expressions of DPSCs cultured on bECM hydrogels were further upregulated by the addition of GFs or osteo/odontogenic medium compared to Col-I treated cells in the same culture conditions. These results demonstrate the potential of the bECM hydrogel scaffolds to stimulate odontogenic differentiation of DPSCs.

Direct pulp capping of permanent teeth in New Zealand general dental practice--a practice based research study.

PubMed

Friedlander, L; McElroy, K; Daniel, B; Cullinan, M; Hanlin, S

2015-06-01

This study aimed to investigate treatment protocols and opinions towards direct pulp capping (DPC) amongst New Zealand (NZ) general dental practitioners (GDP) through a Practice Based Research Network (PBRN) study. Mixed-methods approach using qualitative thematic and quantitative analysis. An on-line survey containing Likert scale items and open-ended questions was distributed to GDPs on the Dental Council of New Zealand (DCNZ) register (2012) to collect information on practitioner demographics, treatment protocols, continuing professional development (CPD) and philosophies towards DPC. RESULTs: Two hundred and ten GDPs from North and South Islands providing care in main centres and rural areas engaged with the PBRN and participated in the study. Almost all performed DPC treatment although it was not a common procedure. DPC was perceived as 'successful' or 'very successful' by 95% of respondents, mostly for cases of reversible pulpitis. Most provided DPC for patients of all ages but younger patients were perceived to have the best clinical outcomes. Calcium hydroxide and MTA were the most commonly used materials for DPC. MTA was believed to have the best outcome but cost and handling properties were barriers to its use. The majority of respondents had participated in CPD related to vital pulp therapy and regarded this treatment as conservative and providing time and financial benefits compared with more invasive treatment. Clinicians' timeframes for assessing healing were variable, and combined clinical and radiographic findings were considered most useful. New Zealand dentists perceive DPC as a successful and conservative treatment in selected cases. The findings have provided insights into engagement of NZ dentists in using research to inform everyday clinical practice through a PBRN study.

Priming Dental Pulp Stem Cells With Fibroblast Growth Factor-2 Increases Angiogenesis of Implanted Tissue-Engineered Constructs Through Hepatocyte Growth Factor and Vascular Endothelial Growth Factor Secretion.

PubMed

Gorin, Caroline; Rochefort, Gael Y; Bascetin, Rumeyza; Ying, Hanru; Lesieur, Julie; Sadoine, Jérémy; Beckouche, Nathan; Berndt, Sarah; Novais, Anita; Lesage, Matthieu; Hosten, Benoit; Vercellino, Laetitia; Merlet, Pascal; Le-Denmat, Dominique; Marchiol, Carmen; Letourneur, Didier; Nicoletti, Antonino; Vital, Sibylle Opsahl; Poliard, Anne; Salmon, Benjamin; Muller, Laurent; Chaussain, Catherine; Germain, Stéphane

2016-03-01

Tissue engineering strategies based on implanting cellularized biomaterials are promising therapeutic approaches for the reconstruction of large tissue defects. A major hurdle for the reliable establishment of such therapeutic approaches is the lack of rapid blood perfusion of the tissue construct to provide oxygen and nutrients. Numerous sources of mesenchymal stem cells (MSCs) displaying angiogenic potential have been characterized in the past years, including the adult dental pulp. Establishment of efficient strategies for improving angiogenesis in tissue constructs is nevertheless still an important challenge. Hypoxia was proposed as a priming treatment owing to its capacity to enhance the angiogenic potential of stem cells through vascular endothelial growth factor (VEGF) release. The present study aimed to characterize additional key factors regulating the angiogenic capacity of such MSCs, namely, dental pulp stem cells derived from deciduous teeth (SHED). We identified fibroblast growth factor-2 (FGF-2) as a potent inducer of the release of VEGF and hepatocyte growth factor (HGF) by SHED. We found that FGF-2 limited hypoxia-induced downregulation of HGF release. Using three-dimensional culture models of angiogenesis, we demonstrated that VEGF and HGF were both responsible for the high angiogenic potential of SHED through direct targeting of endothelial cells. In addition, FGF-2 treatment increased the fraction of Stro-1+/CD146+ progenitor cells. We then applied in vitro FGF-2 priming to SHED before encapsulation in hydrogels and in vivo subcutaneous implantation. Our results showed that FGF-2 priming is more efficient than hypoxia at increasing SHED-induced vascularization compared with nonprimed controls. Altogether, these data demonstrate that FGF-2 priming enhances the angiogenic potential of SHED through the secretion of both HGF and VEGF. ©AlphaMed Press.

Unique proliferation response in odontoblastic cells derived from human skeletal muscle stem cells by cytokine-induced matrix metalloproteinase-3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ozeki, Nobuaki; Hase, Naoko; Kawai, Rie

A pro-inflammatory cytokine mixture (CM: interleukin (IL)-1β, tumor necrosis factor-α and interferon-γ) and IL-1β-induced matrix metalloproteinase (MMP)-3 activity have been shown to increase the proliferation of rat dental pulp cells and murine stem cell-derived odontoblast-like cells. This suggests that MMP-3 may regulate wound healing and regeneration in the odontoblast-rich dental pulp. Here, we determined whether these results can be extrapolated to human dental pulp by investigating the effects of CM-induced MMP-3 up-regulation on the proliferation and apoptosis of purified odontoblast-like cells derived from human skeletal muscle stem cells. We used siRNA to specifically reduce MMP-3 expression. We found that CMmore » treatment increased MMP-3 mRNA and protein levels as well as MMP-3 activity. Cell proliferation was also markedly increased, with no changes in apoptosis, upon treatment with CM and following the application of exogenous MMP-3. Endogenous tissue inhibitors of metalloproteinases were constitutively expressed during all experiments and unaffected by MMP-3. Although treatment with MMP-3 siRNA suppressed cell proliferation, it also unexpectedly increased apoptosis. This siRNA-mediated increase in apoptosis could be reversed by exogenous MMP-3. These results demonstrate that cytokine-induced MMP-3 activity regulates cell proliferation and suppresses apoptosis in human odontoblast-like cells. - Highlights: • Pro-inflammatory cytokines induce MMP-3 activity in human odontoblast-like cells. • Increased MMP-3 activity can promote cell proliferation in odontoblasts. • Specific loss of MMP-3 increases apoptosis in odontoblasts. • MMP-3 has potential as a promising new target for pupal repair and regeneration.« less

Differentiation potential of STRO-1+ dental pulp stem cells changes during cell passaging.

PubMed

Yu, Jinhua; He, Huixia; Tang, Chunbo; Zhang, Guangdong; Li, Yuanfei; Wang, Ruoning; Shi, Junnan; Jin, Yan

2010-05-08

Dental pulp stem cells (DPSCs) can be driven into odontoblast, osteoblast, and chondrocyte lineages in different inductive media. However, the differentiation potential of naive DPSCs after serial passaging in the routine culture system has not been fully elucidated. DPSCs were isolated from human/rat dental pulps by the magnetic activated cell sorting based on STRO-1 expression, cultured and passaged in the conventional culture media. The biological features of STRO-1+ DPSCs at the 1st and 9th passages were investigated. During the long-term passage, the proliferation ability of human STRO-1+ DPSCs was downregulated as indicated by the growth kinetics. When compared with STRO-1+ DPSCs at the 1st passage (DPSC-P1), the expression of mature osteoblast-specific genes/proteins (alkaline phosphatase, bone sialoprotein, osterix, and osteopontin), odontoblast-specific gene/protein (dentin sialophosphoprotein and dentin sialoprotein), and chondrocyte-specific gene/protein (type II collagen) was significantly upregulated in human STRO-1+ DPSCs at the 9th passage (DPSC-P9). Furthermore, human DPSC-P9 cells in the mineralization-inducing media presented higher levels of alkaline phosphatase at day 3 and day 7 respectively, and produced more mineralized matrix than DPSC-P9 cells at day 14. In vivo transplantation results showed that rat DPSC-P1 cell pellets developed into dentin, bone and cartilage structures respectively, while DPSC-P9 cells can only generate bone tissues. These findings suggest that STRO-1+ DPSCs consist of several interrelated subpopulations which can spontaneously differentiate into odontoblasts, osteoblasts, and chondrocytes. The differentiation capacity of these DPSCs changes during cell passaging, and DPSCs at the 9th passage restrict their differentiation potential to the osteoblast lineage in vivo.

A Histopathological Comparison of Pulpal Response to Chitra-CPC and Formocresol used as Pulpotomy Agents in Primary Teeth: A Clinical Trial

PubMed Central

Thomas, Bijimol

2012-01-01

ABSTRACT Preventive measures have helped to minimize the occurrence of dental caries. However, premature loss of primary teeth on account of dental caries still remains a common problem among children. The pulpotomy technique has been the choice for treating vital primary and young permanent teeth with carious, mechanical and traumatic pulp exposures. The ideal pulpotomy medicament should be bioinductive or at least biocompatible, bactericidal and harmless to the pulp and surrounding structures. It should also promote healing of the radicular pulp and prevent bacterial microleakage with the least interference in the physiological process of root resorption. Since the best criteria for judging the effectiveness of a medicament when used for vital pulp therapy is the response that it produces in the pulp. The purpose of the present study was to evaluate and compare the response of human pulp tissue to recently developed Indian material, Sree Chitra-Calcium Phosphate Cement (Chitra-CPC) and formocresol, used as pulpotomy agent in deciduous teeth. Chitra-CPC has been compared with formocresol, taking into account that formocresol is still considered the gold standard in primary tooth pulpotomy. The study was conducted among 10 children in the age group of 8 to 12 years focusing on 20 noncarious primary canines indicated for serial extraction. Each patient received two different pulpotomy procedures—one in each of the primary canines using formocresol and the other with Chitra-CPC as pulpotomy agents. After 70 days, the teeth were extracted and subjected to histological examination. The results did not reveal statistically significant difference between the two groups. But Chitra-CPC gave more favorable results, in respect of pulpal inflammation, dentin bridge formation, quality of dentin bridge and connective tissue in dentin bridge. How to cite this article: Ratnakumari N, Thomas B. A Histopathological Comparison of Pulpal Response to Chitra- CPC and Formocresol used as Pulpotomy Agents in Primary Teeth: A Clinical Trial. Int J Clin Pediatr Dent 2012;5(1):6-13. PMID:25206127

Enamel tissue engineering using subcultured enamel organ epithelial cells in combination with dental pulp cells.

PubMed

Honda, Masaki J; Shinmura, Yuka; Shinohara, Yoshinori

2009-01-01

We describe a strategy for the in vitro engineering of enamel tissue using a novel technique for culturing enamel organ epithelial (EOE) cells isolated from the enamel organ using 3T3-J2 cells as a feeder layer. These subcultured EOE cells retain the capacity to produce enamel structures over a period of extended culture. In brief, enamel organs from 6-month-old porcine third molars were dissociated into single cells and subcultured on 3T3-J2 feeder cell layers. These subcultured EOE cells were then seeded onto a collagen sponge in combination with primary dental pulp cells isolated at an early stage of crown formation, and these constructs were transplanted into athymic rats. After 4 weeks, complex enamel-dentin structures were detected in the implants. These results show that our culture technique maintained ameloblast lineage cells that were able to produce enamel in vivo. This novel subculture technique provides an important tool for tooth tissue engineering. Copyright 2008 S. Karger AG, Basel.

Preliminary Evaluation of Platelet Rich Fibrin-Mediated Tissue Repair in Immature Canine Pulpless Teeth.

PubMed

Wang, Qi Lin; Yang, Pan Pan; Ge, Li Hong; Liu, He

2016-03-01

To evaluate the use of platelet-rich fibrin (PRF) in the regenerative therapy of immature canine permanent teeth. Eight immature premolars of beagle dogs were pulp extracted and cleaned with irrigation, then divided into two groups of empty root canals and those filled with a PRF clot. All of the eight premolars were sealed with mineral trioxide aggregate and glass ionomer cement. Two premolars were left naturally grown as a positive control. The root development was assessed radiographically and histologically after 12 weeks. The radiological findings showed greater increases in the thickness of lateral dentinal wall in the PRF group than in the vacant group. Histologically, dental-associated mineral tissue, connective tissue, and bone-like mineral tissue grew into the root canals independent of PRF clot use. The PRF was able to increase the thickness of dental-associated mineral tissue. However, the vital tissue differed from the pulp dentin complex. Our study demonstrated the feasibility of using PRF-mediated regenerative therapy in pulpless immature teeth for improving tissue repair.

[Cloning and characterization of genes differentially expressed in human dental pulp cells and gingival fibroblasts].

PubMed

Wang, Zhong-dong; Wu, Ji-nan; Zhou, Lin; Ling, Jun-qi; Guo, Xi-min; Xiao, Ming-zhen; Zhu, Feng; Pu, Qin; Chai, Yu-bo; Zhao, Zhong-liang

2007-02-01

To study the biological properties of human dental pulp cells (HDPC) by cloning and analysis of genes differentially expressed in HDPC in comparison with human gingival fibroblasts (HGF). HDPC and HGF were cultured and identified by immunocytochemistry. HPDC and HGF subtractive cDNA library was established by PCR-based modified subtractive hybridization, genes differentially expressed by HPDC were cloned, sequenced and compared to find homogeneous sequence in GenBank by BLAST. Cloning and sequencing analysis indicate 12 genes differentially expressed were obtained, in which two were unknown genes. Among the 10 known genes, 4 were related to signal transduction, 2 were related to trans-membrane transportation (both cell membrane and nuclear membrane), and 2 were related to RNA splicing mechanisms. The biological properties of HPDC are determined by the differential expression of some genes and the growth and differentiation of HPDC are associated to the dynamic protein synthesis and secretion activities of the cell.

Estrogen deficiency inhibits the odonto/osteogenic differentiation of dental pulp stem cells via activation of the NF-κB pathway.

PubMed

Wang, Yanping; Yan, Ming; Yu, Yan; Wu, Jintao; Yu, Jinhua; Fan, Zhipeng

2013-06-01

Various factors can affect the functions of dental pulp stem cells (DPSCs). However, little knowledge is available about the effects of estrogen deficiency on the differentiation of DPSCs. In this study, an estrogen-deficient rat model was constructed and multi-colony-derived DPSCs were obtained from the incisors of ovariectomized (OVX) or sham-operated rats. Odonto/osteogenic differentiation and the possible involvement of the nuclear factor kappa B (NF-κB) pathway in the OVX-DPSCs/Sham-DPSCs of these rats were then investigated. OVX-DPSCs presented decreased odonto/osteogenic capacity and an activated NF-κB pathway, as compared with Sham-DPSCs. When the cellular NF-κB pathway was specifically inhibited by BMS345541, the odonto/osteogenic potential in OVX-DPSCs was significantly upregulated. Thus, estrogen deficiency down-regulated the odonto/osteogenic differentiation of DPSCs by activating NF-κB signaling and inhibition of the NF-κB pathway effectively rescued the decreased differentiation potential of DPSCs.

Properties of the "Orgamax" osteoplastic material made of a demineralized allograft bone

NASA Astrophysics Data System (ADS)

Podorognaya, V. T.; Kirilova, I. A.; Sharkeev, Yu. P.; Uvarkin, P. V.; Zhelezny, P. A.; Zheleznaya, A. P.; Akimova, S. E.; Novoselov, V. P.; Tupikova, L. N.

2016-08-01

We investigated properties of the "Orgamax" osteoplastic material, which was produced from a demineralized bone, in the treatment of extensive caries, in particular chronic pulpitis of the permanent teeth with unformed roots in children. The "Orgamax" osteoplastic material consists of demineralized bone chips, a collagen additive, and antibiotics. The surface morphology of the "Orgamax" osteoplastic material is macroporous, with the maximum pore size of 250 µm, whereas the surface morphology of the major component of "Orgamax", demineralized bone chips, is microporous, with a pore size of 10-20 µm. Material "Orgamax" is used in the treatment of complicated caries, particularly chronic pulpitis of permanent teeth with unformed roots in children. "Orgamax" filling a formed cavity exhibits antimicrobial properties, eliminates inflammation in the dental pulp, and, due to its osteoconductive and osteoinductive properties, undergoes gradual resorption, stimulates regeneration, and provides replacement of the defect with newly formed tissue. The dental pulp viability is completely restored, which ensures the complete formation of tooth roots with root apex closure in the long-term period.

Antimicrobial properties and dental pulp stem cell cytotoxicity using carboxymethyl cellulose-silver nanoparticles deposited on titanium plates

PubMed Central

Laredo-Naranjo, Martha Alicia; Carrillo-Gonzalez, Roberto; De La Garza-Ramos, Myriam Angelica; Garza-Navarro, Marco Antonio; Torre-Martinez, Hilda H. H.; Del Angel-Mosqueda, Casiano; Mercado-Hernandez, Roberto; Carrillo-Fuentevilla, Roberto

2016-01-01

Abstract Objective: To evaluate the antimicrobial properties and dental pulp stem cells (DPSCs) cytotoxicity of synthesized carboxymethyl cellulose-silver nanoparticles impregnated on titanium plates. Material and methods: The antibacterial effect of silver nanoparticles in a carboxymethyl cellulose matrix impregnated on titanium plates (Ti-AgNPs) in three concentrations: 16%, 50% and 100% was determined by adding these to bacterial cultures of Streptococcus mutans and Porphyromonas gingivalis. The Ti-AgNPs cytotoxicity on DPSCs was determined using a fluorimetric cytotoxicity assay with 0.12% chlorhexidine as a positive control. Results: Silver nanoparticles in all concentrations were antimicrobial, with concentrations of 50% and 100% being more cytotoxic with 4% cell viability. Silver nanoparticles 16% had a cell viability of 95%, being less cytotoxic than 0.12% chlorhexidine. Conclusions: Silver nanoparticles are a promising structure because of their antimicrobial properties. These have high cell viability at a concentration of 16%, and are less toxic than chlorhexidine. PMID:28642914

Age estimation by assessment of pulp chamber volume: a Bayesian network for the evaluation of dental evidence.

PubMed

Sironi, Emanuele; Taroni, Franco; Baldinotti, Claudio; Nardi, Cosimo; Norelli, Gian-Aristide; Gallidabino, Matteo; Pinchi, Vilma

2017-11-14

The present study aimed to investigate the performance of a Bayesian method in the evaluation of dental age-related evidence collected by means of a geometrical approximation procedure of the pulp chamber volume. Measurement of this volume was based on three-dimensional cone beam computed tomography images. The Bayesian method was applied by means of a probabilistic graphical model, namely a Bayesian network. Performance of that method was investigated in terms of accuracy and bias of the decisional outcomes. Influence of an informed elicitation of the prior belief of chronological age was also studied by means of a sensitivity analysis. Outcomes in terms of accuracy were adequate with standard requirements for forensic adult age estimation. Findings also indicated that the Bayesian method does not show a particular tendency towards under- or overestimation of the age variable. Outcomes of the sensitivity analysis showed that results on estimation are improved with a ration elicitation of the prior probabilities of age.

The effect of UV-Vis to near-infrared light on the biological response of human dental pulp cells

NASA Astrophysics Data System (ADS)

Hadis, Mohammed A.; Cooper, Paul R.; Milward, Michael R.; Gorecki, Patricia; Tarte, Edward; Churm, James; Palin, William M.

2015-03-01

Human dental pulp cells (DPCs) were isolated and cultured in phenol-red-free α-MEM/10%-FCS at 37ºC in 5% CO2. DPCs at passages 2-4 were seeded (150μL; 25,000 cell/ml) in black 96-microwell plates with transparent bases. 24h post-seeding, cultures were irradiated using a bespoke LED array consisting of 60 LEDs (3.5mW/cm2) of wavelengths from 400-900nm (10 wavelengths, n=6) for time intervals of up to 120s. Metabolic and mitochondrial activity was assessed via a modified MTT assay. Statistical differences were identified using multi-factorial analysis of variance and post-hoc Tukey tests (P=0.05). The biological responses were significantly dependent upon post-irradiation incubation period, wavelength and exposure time (P<0.05). At shorter wavelength irradiances (400nm), a reduction in mitochondrial activity was detected although not significant, whereas longer wavelength irradiances (at 633, 656, 781 and 799nm) significantly increased mitochondrial activity (P<0.05) in DPCs. At these wavelengths, mitochondrial activity was generally increased for exposures less than 90s with 30s exposures being most effective with 24h incubation. Increasing the post-irradiation incubation period increased the measured response and identified further significance (P<0.05). The biological responses of human DPCs were wavelength, exposure-time and incubation period dependent. The optimisation of irradiation parameters will be key to the successful application of LLLT in dentistry.

Tetracycline-regulated expression of OLIG2 gene in human dental pulp stem cells lead to mouse sciatic nerve regeneration upon transplantation.

PubMed

Askari, N; Yaghoobi, M M; Shamsara, M; Esmaeili-Mahani, S

2015-10-01

Numerous studies have indicated dental pulp stem cells (DPSCs) potency to differentiate into several types of cell lineages. Oligodendrocyte lineage transcription factor 2 (OLIG2) plays an important role in the oligodendrogenic pathway. In this study, a tetracycline (Tet)-inducible system expressing OLIG2 gene was transfected into human DPSCs to direct their differentiation toward oligodendrocyte progenitor cells (OPCs). Following induction, the expression of stage-specific markers was studied by Reverse Transcription quantitative Polymerase Chain Reaction (RT-qPCR), immunocytochemistry and western blotting. In the following, the cells were transplanted into the mouse model of local sciatic demyelination damage by lysolecithin. Recovery of lysolecithin-induced lesions in sciatic nerve was studied by treadmill exercise, von Frey filament test and hind paw withdrawal in response to a thermal stimulus. Improvement of behavioral symptoms was efficiently observed from the second week to the sixth week post-transplantation. Our findings showed that exogenous expression of the OLIG2 gene by a Tet-regulated system could be used as an efficient way to induce the differentiation of DPSCs into functional oligodendrocytes. Meanwhile, the DPSC-derived OPCs have relevant therapeutic potential in the animal model of sciatic nerve injury and therefore might represent a valuable tool for stem cell-based therapy in inflammatory and degenerative diseases of the peripheral and central nervous systems (CNSs). Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Differences in pediatric dental services under general anesthesia for Medicaid and military dependent children.

PubMed

Johnson, M B; Cappelli, D P; Bradshaw, B S; Mabry, J C

2010-01-01

This study's purpose was to compare pediatric dental services provided for Medicaid and military dependent children to determine if differences in dental treatment choices exist based on site and payment method. Subjects included 120 Medicaid patients at the University of Texas Health Science Center at San Antonio and 120 military dependents at Lackland Air Force Base, Texas. Demographic data and treatment information were abstracted for children younger than 6 years old receiving dental treatment under general anesthesia between 2002 and 2006. Data was analyzed using Wilcoxon rank sum, Kruskal-Wallis, and Fisher's exact tests. The Medicaid recipients were younger (40.2 vs 49.8 months, P<.001) and more likely to be Hispanic (78% vs 30%, P<.001). The means of decayed teeth, fillings, and stainless steel crowns did not differ between sites. Medicaid children received more composite fillings (P<.001), fewer amalgam fillings (P<.001), fewer pulp therapies (P<.001), more extractions (P=.01), and fewer sealants (P<.001). Age and gender did not affect decay rates, but those of Hispanic ethnicity did experience more decay than non-Hispanics (9.5 vs 8.6, P=.02). This study found no difference in the number of less conservative, albeit more costly, procedures performed with Medicaid children at a university compared to military dependents at a military base.

Preference and usage of intracanal medications during endodontic treatment.

PubMed

Madarati, Ahmad A; Zafar, Muhammad S; Sammani, Aya M N; Mandorah, Ayman O; Bani-Younes, Hamzah A

2017-07-01

To investigate the preferences of general dental practitioners (GDPs) and endodontists in using endodontic intra-canal medications (ICMs). This observational and descriptive study was conducted in 2014 in the western province of Saudi Arabia. Following ethical clearance and 2 pilot studies, a web-based questionnaire was electronically sent to 375 randomly and systematically selected GDPs and all endodontists in the western province (n=49). An accompanying e-mail explained the study's aims and confirmed that the data yielded would remain confidential. The responses were collected, and the data was analyzed using the Chi-square test at p=0.05. Significantly, the highest proportion of respondents (53.7%) reported disinfection of the root canals as the main function of ICMs. Calcium hydroxide (CH) was the preferred material of the majority of those who used the same ICM in all cases (85.7%). While the vast majority of all endodontists (87.5%) used CH after pulp extirpation, 48.5% of GDPs used formocresol (p less than 0.001). Almost 30% of those who used ICMs after pulp extirpation did not do so after cleaning and shaping of vital cases. Most endodontists used CH (62.5%) and antibiotics (37.5%) in necrotic pulp cases without apical lesions, which were significantly greater than those of GDPs who did the same (43.8% and 17.2%). Participants were aware that the main function of ICMs is disinfection of the root canal system. However, it is clear that GDPs should reduce their reliance on phenol- and formaldehyde-based medications. There was a distinct trend toward the use of ICMs, especially CH, in necrotic pulp cases.

Quantification of taurodontism: interests in the early diagnosis of hypohidrotic ectodermal dysplasia.

PubMed

Gros, C-I; Clauss, F; Obry, F; Manière, M C; Schmittbuhl, M

2010-04-01

The aim of this study was to provide a quantification of taurodontism in Hypohidrotic Ectodermal Dysplasia (HED) and to report its occurrence in a cohort of HED patients to assess phenotypic-genotypic correlations. Of 68 HED patients retrospectively reviewed, 16 patients aged 7-51 years were selected and compared with a control sample (n = 351). The pulp surface index of the first lower permanent molar was calculated from the panoramic radiograph of each individual, and statistical comparisons between the HED patients and the control sample were performed. Whatever the genetic disorder, 81.25% of the HED patients exhibited a relative enlargement (>or=1 s.d.) of the pulp. Major deviations (>5 s.d.) were respectively related to men affected by large deletion of the EDA gene or missense mutation. The autosomal recessive form was linked to a relative moderate pulp enlargement (3.44 s.d.). In NEMO forms, the increase of pulp size in men appeared to be less marked than in EDA mutations. This study provides for the first time an objective assessment of pulp enlargement in HED patients, and the various degrees of taurodontism depicted could be interesting dental phenotypic markers of HED forms.

Effectiveness of radio waves application in modern general dental procedures: An update.

PubMed

Qureshi, Arslan; Kellesarian, Sergio Varela; Pikos, Michael A; Javed, Fawad; Romanos, Georgios E

2017-01-01

The purpose of the present study was to review indexed literature and provide an update on the effectiveness of high-frequency radio waves (HRW) application in modern general dentistry procedures. Indexed databases were searched to identify articles that assessed the efficacy of radio waves in dental procedures. Radiosurgery is a refined form of electrosurgery that uses waves of electrons at a radiofrequency ranging between 2 and 4 MHz. Radio waves have also been reported to cause much less thermal damage to peripheral tissues compared with electrosurgery or carbon dioxide laser-assisted surgery. Formation of reparative dentin in direct pulp capping procedures is also significantly higher when HRW are used to achieve hemostasis in teeth with minimally exposed dental pulps compared with traditional techniques for achieving hemostasis. A few case reports have reported that radiosurgery is useful for procedures such as gingivectomy and gingivoplasty, stage-two surgery for implant exposure, operculectomy, oral biopsy, and frenectomy. Radiosurgery is a relatively modern therapeutic methodology for the treatment of trigeminal neuralgia; however, its long-term efficacy is unclear. Radio waves can also be used for periodontal procedures, such as gingivectomies, coronal flap advancement, harvesting palatal grafts for periodontal soft tissue grafting, and crown lengthening. Although there are a limited number of studies in indexed literature regarding the efficacy of radio waves in modern dentistry, the available evidence shows that use of radio waves is a modernization in clinical dentistry that might be a contemporary substitute for traditional clinical dental procedures.

Injectable scaffolds: Preparation and application in dental and craniofacial regeneration

PubMed Central

Chang, Bei; Ahuja, Neelam; Ma, Chi; Liu, Xiaohua

2016-01-01

Injectable scaffolds are appealing for tissue regeneration because they offer many advantages over pre-formed scaffolds. This article provides a comprehensive review of the injectable scaffolds currently being investigated for dental and craniofacial tissue regeneration. First, we provide an overview of injectable scaffolding materials, including natural, synthetic, and composite biomaterials. Next, we discuss a variety of characteristic parameters and gelation mechanisms of the injectable scaffolds. The advanced injectable scaffolding systems developed in recent years are then illustrated. Furthermore, we summarize the applications of the injectable scaffolds for the regeneration of dental and craniofacial tissues that include pulp, dentin, periodontal ligament, temporomandibular joint, and alveolar bone. Finally, our perspectives on the injectable scaffolds for dental and craniofacial tissue regeneration are offered as signposts for the future advancement of this field. PMID:28649171

CKIP-1 suppresses odontoblastic differentiation of dental pulp stem cells via BMP2 pathway and can interact with NRP1.

PubMed

Song, Yihua; Wang, Chenfei; Gu, Zhifeng; Cao, Peipei; Huang, Dan; Feng, Guijuan; Lian, Min; Zhang, Ye; Feng, Xingmei; Gao, Zhenran

2018-05-31

Casein kinase 2 interacting protein-1 (CKIP-1) is a recently discovered intracellular regulator of bone formation, muscle cell differentiation and tumor cell proliferation. Our study aims to identify the inhibition of BMP2-Smad1/5 signaling by CKIP-1 in odontoblastic differentiation of human dental pulp stem cells (DPSCs). DPSCs infected CKIP-1 siRNA or transfected CKIP-1 full-length plasmid were cultured in odontoblastic differentiation medium or added noggin (200 ng/mL) for 21 days. We examined the effects of CKIP-1 on odontoblastic differentiation, mineralized nodules formation and interaction by western blot, real-time polymerase chain reaction (RT-PCR), alkaline phosphatase (ALP) staining, alizarin red S staining and immunoprecipitation. Firstly, we have demonstrated that CKIP-1 expression markedly decreased time-dependently along with cell odontoblastic differentiation. Indeed, the silence of CKIP-1 up-regulated odontoblastic differentiation via BMP2-Smad1/5 signaling, while CKIP-1 over-expression had a negative effect on odontoblastic differentiation of DPSCs. Furthermore, CKIP-1 could interact with Neuropilin-1 (NRP1). This work provides data that it advocates a novel perception on odontoblastic differentiation of DPSCs. Therefore, inhibiting the expression of CKIP-1 may be of great significance to the development of dental caries.

[Lasers in dentistry. Part B--Interaction with biological tissues and the effect on the soft tissues of the oral cavity, the hard tissues of the tooth and the dental pulp].

PubMed

Moshonov, J; Stabholz, A; Leopold, Y; Rosenberg, I; Stabholz, A

2001-10-01

The interaction of laser energy with target tissue is mainly determined by two non operator-dependent factors: the specific wavelength of the laser and the optical properties of the target tissues. Power density, energy density, pulse repetition rate, pulse duration and the mode of energy transferring to the tissue are dictated by the clinician. Combination of these factors enables to control optimal response for the clinical application. Four responses are described when the laser beam hits the target tissue: reflection, absorption, transmission and scattering. Three main mechanisms of interaction between the laser and the biological tissues exist: photothermic, photoacoustic and photochemical. The effect of lasers on the soft tissues of the oral cavity is based on transformation of light energy into thermal energy which, in turn heats the target tissue to produce the desirable effect. In comparison to the scalpel used in surgical procedures, the laser beam is characterized by tissue natural sterility and by minimum bleeding during the surgical procedures due to blood vessels welding. The various effects achieved by the temperature elevation during the laser application on the soft tissue are: I. coagulation and hemostasis II. tissue sterilization III. tissue welding IV. incision and excision V. ablation and vaporization Ablation and melting are the two basic modalities by which the effect of lasers on the hard tissues of the tooth is produced. When discussing the effect of laser on dental hard tissues, the energy absorption in the hydroxyapatite plays a major role in addition to its absorption in water. When laser energy is absorbed in the water of the hard tissues, a rapid volume expansion of the evaporating water occurs as a result of a substantial temperature elevation in the interaction site. Microexplosions are produced causing hard tissue disintegration. If pulp temperatures are raised beyond 5 degrees C level, damage to the dental pulp is irreversible. Histologically, after laser ablation, presence of odontoblastic nuclei is important. Consistency and composition of the intracellular tissue is another factor influencing cell viability. If heat is intensive and exists for an extended time, the consistency of the intracellular ground substance may not be preserved. Accordingly, the application of excessive energy densities has been shown to result in significant damage to pulp tissue and in particular to odontoblasts. Studies showed that the use of Er:YAG laser to treat dental hard tissues is both safe and effective for caries removal, cavity preparation and enamel etching.

Pulp regeneration after non-infected and infected necrosis, what type of tissue do we want? A review.

PubMed

Andreasen, Jens O; Bakland, Leif K

2012-02-01

Regeneration (revitalization) of infected necrotic pulp tissue has been an important issue in endodontics for more than a decade. Based on a series of case reports, there appears to be evidence that new soft tissue can enter the root canal with a potential for subsequent hard tissue deposition resulting in a narrowing of the root canal. Very little is presently known about the exact nature of this tissue growing into the canal and how it may behave in the long term. In the case of regeneration of necrotic non-infected pulp tissue, a series of clinical and histological studies have shown that such events may take place in four variants: (i) Revascularization of the pulp with accelerated dentin formation leading to pulp canal obliteration. This event has a good long-term prognosis. (ii) Ingrowth of cementum and periodontal ligament (PDL). The long-term prognosis for this event is not known. (iii) Ingrowth of cementum, PDL, and bone. The long-term prognosis is only partly known, but cases developing an internal ankylosis have been described. (iv) Ingrowth of bone and bone marrow is a rare phenomenon and the long-term prognosis does not appear to be good. Based on current knowledge, expectations with respect to pulp regeneration (revitalization) of infected necrotic dental pulps are difficult to predict; more information than now available is needed before procedures for pulpal regeneration can be routinely recommended with a predictable long-term prognosis. © 2011 John Wiley & Sons A/S.

Evaluation of a Commercially Available Hyaluronic Acid Hydrogel (Restylane) as Injectable Scaffold for Dental Pulp Regeneration: An In Vitro Evaluation.

PubMed

Chrepa, Vanessa; Austah, Obadah; Diogenes, Anibal

2017-02-01

Regenerative endodontic procedures (REPs) are viable alternatives for treating immature teeth, yet these procedures do not predictably lead to pulp-dentin regeneration. A true bioengineering approach for dental pulp regeneration requires the incorporation of a scaffold conducive with the regeneration of the pulp-dentin complex. Several materials have been proposed as scaffolds for REPs; nonetheless, the majority are not eligible for immediate clinical chairside use. Thus, the aim of this study was to evaluate Restylane, a Food and Drug Administration-approved hyaluronic acid-based gel, as possible scaffold for REPs. Stem cells of the apical papilla (SCAP) were cultured either alone or in mixtures with either Restylane or Matrigel scaffolds. Groups were cultured in basal culture medium for 6, 24, and 72 hours, and cell viability was assessed. For the mineralizing differentiation experiments, groups were cultured in differentiation medium either for 7 days and processed for alkaline phosphatase activity or for 14 days and processed for gene expression by using quantitative reverse-transcription polymerase chain reaction. SCAP in basal medium served as control. Cell encapsulation in either Restylane or Matrigel demonstrated reduced cell viability compared with control. Nonetheless, cell viability significantly increased in the Restylane group in the course of 3 days, whereas it decreased significantly in the Matrigel group. Restylane promoted significantly greater alkaline phosphatase activity and upregulation of dentin sialophosphoprotein, dentin matrix acidic phosphoprotein-1, and matrix extracellular phosphoglycoprotein, compared with control. A Food and Drug Administration-approved hyaluronic acid-based injectable gel promoted SCAP survival, mineralization, and differentiation into an odontoblastic phenotype and may be a promising scaffold material for REPs. Published by Elsevier Inc.

Effects of fibroblast growth factor-2 on the expression and regulation of chemokines in human dental pulp cells.

PubMed

Kim, Young-Suk; Min, Kyung-San; Jeong, Dong-Ho; Jang, Jun-Hyeog; Kim, Hae-Won; Kim, Eun-Cheol

2010-11-01

Fibroblast growth factor-2 (FGF-2) participates in both hematopoiesis and osteogenesis; however, the effects of FGF-2 on chemokines during odontoblastic differentiation have not been reported. This study investigated whether human dental pulp cells (HDPCs) treated with FGF-2 could express chemokines during differentiation into odontoblastic cells and sought to identify its underlying mechanism of action. To analyze differentiation, we measured alkaline phosphatase (ALP) activity, calcified nodule formation by alizarin red staining, and marker RNA (mRNA) expression by reverse-transcriptase polymerase chain reaction (RT-PCR). Expression of chemokines, such as interleukin-6 (IL-6), IL-8, monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-1α (MIP-1α), and MIP-3α, were evaluated by RT-PCR. ALP activity, the mineralization, and mRNA expression for odontoblastic markers were enhanced by FGF-2 in HDPCs. FGF-2 also up-regulated the expression of IL-6, IL-8, MCP-1, MIP-1α, and MIP-3α mRNAs, which were attenuated by inhibitors of p38, ERK1/2 and p38 MAP kinases, protein kinase C, phosphoinositide-3 kinase, and NF-κB. Taken together, these data suggest that FGF-2 plays a role not only as a differentiation inducing factor in the injury repair processes of pulpal tissue but also as a positive regulator of chemokine expression, which may help in tissue engineering and pulp regeneration using HDPCs. However, the fate of odontoblastic or osteoblastic differentiation, effective local delivery for FGF-2, interaction of chemotatic and odontogenic factors, and other limitations will need to be overcome before a major modality for the treatment of pulp disease. Copyright © 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Microscopic study of dental hard tissues in primary teeth with Dentinogenesis Imperfecta Type II: Correlation of 3D imaging using X-ray microtomography and polarising microscopy.

PubMed

Davis, Graham R; Fearne, Janice M; Sabel, Nina; Norén, Jörgen G

2015-07-01

The aim of this study was to examine the histological appearance of dental hard tissues in primary teeth from children with DI using conventional polarised light microscopy and correlate that with 3D imaging using X-ray microtomograpy (XMT) to gain a further understanding of the dentine structure of teeth diagnosed with dentinogenesis imperfecta. Undecalcified sections of primary teeth from patients diagnosed with Dentinogenesis Imperfecta Type II were examined using polarised light microscopy. XMT was employed for 3D-imaging and analysis of the dentine. The polarised light microscopy and XMT revealed tubular structures in the dentine seen as vacuoles coinciding with the path of normal dentinal tubules but not continuous tubules. The size of the tubules was close to that of capillaries. The largest tubular structures had a direction corresponding to where the pulp tissue would have been located during primary dentine formation. The dysfunctional mineralisation of the dentine and obliteration of the pulp evidently leaves blood vessels in the dentine which have in the main been tied off and, in the undecalcified sections, appear as vacuoles. Although from radiographs, the pulp in teeth affected by Dentinogenesis Imperfect type II appears to be completely obliterated, a network of interconnected vessels may remain. The presence of large dentinal tubules and blood vessels, or the remnants of blood vessels, could provide a pathway for bacteria from the oral cavity. This might account for why some of these teeth develop periapical abscesses in spite of apparently having no pulp. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of ultrasonic dental scaling on pulp vitality in dogs: an experimental study.

PubMed

Vérez-Fraguela, J L; Vives Vallés, M A; Ezquerra Calvo, L J

2000-06-01

We investigated whether dental pulpal damage is produced as a result of the application of an ultrasonic scaler commonly used in clinical veterinary dentistry. Using methods developed in preliminary studies, we examined six dogs. The radiographic thickness of the dentin and pulp cavity was measured. The ultrasonic scaler was applied to maxillary and mandibular premolar teeth for 30, 60, or 90 seconds, without the use of water as a coolant. The temperatures of the room, the pulp canal on untreated incisor teeth, the cheek, the gingival sulcus, and the dentin of the affected teeth were recorded using a probe with a thermistor attached to a resistivity meter and inserted in the dentin to a depth of 1 mm. Two weeks following scaling, the teeth were extracted for microscopic examination. In another dog serving as a control, the temperature of the dentin was increased to between 45 degrees C (113 degrees F) and 47 degrees C (117 degrees F) and the premolar teeth were removed for microscopic examination 15 days later. We concluded that the application of an uncooled ultrasonic scaler for 90 seconds did not increase the temperature of the dentin. However, damage comparable with acute pulpitis resulted as a consequence of the ultrasonic effect, similar to the effects produced by the 45-47 degrees C heat applied in the control animal.