Inflamed Pulp Tissue Research Articles

Response of Inflamed Pulps of Rat Molars after Capping with Pulp-capping Material Containing Fluocinolone Acetonide

IntroductionCapping inflamed dental pulp tissue is currently a controversial issue. To reduce pulp inflammation and stimulate pulp healing, a pulp-capping material containing fluocinolone acetonide (PCFA) has been developed. This study was aimed to evaluate the inflammatory response and hard tissue formation of inflamed dental pulps of rat maxillary molars after capping with Dycal, mineral trioxide aggregate (MTA), or PCFA. MethodsSixty maxillary rat molars were exposed to the oral environment for 48 hours. The exposed pulps were randomly divided into 6 groups (n = 10) according to pulp-capping materials (Dycal, MTA, or PCFA) and time (8 or 30 days). The cavities were capped and sealed with Fuji II LC. The animals were sacrificed after 8 and 30 days. Histologic specimens were prepared and evaluated for inflammatory response and hard tissue formation. ResultsEight days after pulp capping, all experimental groups showed disruption of the odontoblast layer in areas corresponding to the pulpal exposure. Acute inflammation was found in 80%, 60%, and 40% of samples in the Dycal, MTA, and PCFA groups, respectively. PCFA significantly decreased the pulp inflammation compared with Dycal. After 30 days, slight to moderate inflammation was found in all experimental groups. Hard tissue formation was found in 78%, 63%, and 100% of samples in the Dycal, MTA, and PCFA groups, respectively. No significant difference was found among the experimental groups. ConclusionsPulp capping with PCFA reduced the inflammation and stimulated hard tissue formation in the exposed pulps of rat molars. It may be used as a pulp-capping agent in inflamed pulps.

Archaea prevalence in inflamed pulp tissues.

Archaea have been detected in several ecological niches of the human body such as the large intestine, skin, vagina as well as the oral cavity. At present, archaea are recognized as nonpathogenic microorganisms. However, some data indicate that they may be involved in the etiopathogenesis of several diseases, including intestinal diseases as well as oral diseases: periodontitis, peri-implantitis and endodontitis. In this study, on the basis of 16S rRNA gene sequence analysis, we examined whether archaea might be present in inflamed pulp tissues and contribute to the development of endodontic infection. In comparison, we also determined selected bacterial species associated with endodontitis. We detected archaea in 85% of infected endodontic samples. In addition, Prevotella intermedia, Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola were present in inflamed pulp tissue samples and Treponema denticola occurred with the highest frequency (70%). Further analysis revealed the presence of methanogenic archaea in analyzed samples. Direct sequencing of archaeal 16S rRNA gene PCR products indicated the occurrence of methanogenic archaea in inflamed pulp tissues; phylogenetically most similar were Methanobrevibacter oralis and Methanobrevibacter smithii. Therefore, our results show that methanogenic archaea are present in inflamed pulp tissues and may participate in the development of endodontic infection.

Rotary Fatigue Testing Machine to Determine the Fatigue Life of NiTi alloy Wires and Endondontic Files

Endodontic rotary file instruments used to treat root canals in dentistry suffered breakthrough transformations in recent years when stainless steel was replaced by Nickel-Titanium (NiTi). NiTi alloys used in Endodontics possess superelastic properties at body temperature (37C) that bring many advantages on the overall performance of the root-canal treatment. They can follow curved root canals more easily than stainless steel instruments and have been reported to be more effective in the removal of the inflamed pulp tissue and protection of the tooth structure. However, these instruments eventually fracture under cyclic bending loading due to fatigue, without any visible signals of degradation to the practitioner. This problem brought new challenges on how new instruments should be tested, as NiTi alloys are highly non-linear and present a large hysteresis cycle in the Elastic domain. Current existing standards are only available for Stainless Steel testing. Thus, many authors have attempted to design systems that can test NiTi endodontic files under fatigue loads. However, no approach has been universally adopted by the community yet, as in most cases they are based on empirical set ups. Following a more systematic approach, this work presents the results of rotary fatigue tests for several NiTi wires from different manufacturers (MemryTM and EuroflexTM). The tests were done on a versatile fully automatic rotary bending testing machine. The formulation is also presented, where the material strength reduction can be quantified from the determination of the strain and the number of cycles until failure.

A review on vital pulp therapy in primary teeth.

Maintaining deciduous teeth in function until their natural exfoliation is absolutely necessary. Vital pulp therapy (VPT) is a way of saving deciduous teeth. The most important factors in success of VPT are the early diagnosis of pulp and periradicular status, preservation of the pulp vitality and proper vascularization of the pulp. Development of new biomaterials with suitable biocompatibility and seal has changed the attitudes towards preserving the reversible pulp in cariously exposed teeth. Before exposure and irreversible involvement of the pulp, indirect pulp capping (IPC) is the treatment of choice, but after the spread of inflammation within the pulp chamber and establishment of irreversible pulpitis, removal of inflamed pulp tissue is recommended. In this review, new concepts in preservation of the healthy pulp tissue in deciduous teeth and induction of the reparative dentin formation with new biomaterials instead of devitalization and the consequent destruction of vital tissues are discussed.

Muramyl dipeptide activates human beta defensin 2 and pro-inflammatory mediators through Toll-like receptors and NLRP3 inflammasomes in human dental pulp cells.

The expression levels of intracellular pyrin domain-containing 3 (NLRP3) and microbial pattern-recognition receptors, such as nucleotide-binding oligomerization domain 2 (NOD2), have been reported in human dental pulp cells (HDPCs) and inflamed dental pulp tissue, but the role of NLRP3 and Toll-like receptors (TLRs) in the production of human beta defensin 2 (hBD2) and inflammatory cytokines against invading pathogens remains poorly defined. The aim of this study was to determine whether the NOD2 ligand muramyl dipeptide (MDP) upregulates hBD2 and inflammatory cytokines and whether this response is dependent on TLRs and NLRP inflammasomes in HDPCs. The effects of MDP on the expression of hBD2, TLRs, inflammasomes, and pro-inflammatory mediators in HDPCs were examined using Western blotting and reverse transcription-polymerase chain reaction. Levels of pro-inflammatory cytokines, such as nitric oxide (NO) and prostaglandin E2 (PGE2), were determined by enzyme-linked immunosorbent assay. MDP upregulated hBD2, TLR2, and TLR4 mRNAs and protein levels in a dose- and time-dependent manner. TLR2 and TLR4 neutralizing blocking antibodies and NOD2- and hBD2-specific small interfering RNAs (siRNAs) attenuated the MDP-induced production of NO, PGE2, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and IL-8 and upregulated inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX2) in HDPCs. Additionally, MDP activated inflammasome-related genes, such as NLRP3, caspase 1, apoptotic speck protein containing a caspase recruitment domain, and IL-1β. Furthermore, silencing of the NLRP3 gene using a siRNA significantly decreased the MDP-induced expression of hBD2 and cytokines, such as iNOS-derived NO, COX2, PGE2, TNF-α, IL-6, and IL-8. These results suggest that NOD2 activates the TLR2, TLR4, and NLRP3 inflammasome-signaling pathways in HDPCs to induce the production of multiple inflammatory mediators and antimicrobial peptides, which in turn promote pulp immune defense against microbial challenge. The TLR and NLRP3 inflammasome pathways may represent an important modulatory mechanism of immune defense responses during the progression of pulpitis. Our results suggest that local inhibition of NLRP3 and TLRs may reduce the impact of cytokine-mediated host destructive processes in pulpitis.

Detection of Helicobacter pylori DNA in inflamed dental pulp specimens from Japanese children and adolescents

The oral cavity has been implicated as a source of Helicobacter pylori infection in childhood. Various PCR methods have been used to detect H. pylori DNA in oral specimens with various detection rates reported. Such disparity in detection rates complicates the estimation of the true infection rate of H. pylori in the oral cavity. In the present study, we constructed a novel PCR system for H. pylori detection and used it to analyse oral specimens. Firstly, the nucleotide alignments of genes commonly used for H. pylori detection were compared using the complete genome information for 48 strains registered in the GenBank database. Candidate primer sets with an estimated amplification size of approximately 300-400 bp were selected, and the specificity and sensitivity of the detection system using each primer set were evaluated. Five sets of primers targeting ureA were considered appropriate, of which a single primer set was chosen for inclusion in the PCR system. The sensitivity of the system was considered appropriate and its detection limit established as one to ten cells per reaction. The novel PCR system was used to examine H. pylori distribution in oral specimens (40 inflamed pulp tissues, 40 saliva samples) collected from Japanese children, adolescents and young adults. PCR analysis revealed that the detection rate of H. pylori in inflamed pulp was 15 %, whereas no positive reaction was found in any of the saliva specimens. Taken together, our novel PCR system was found to be reliable for detecting H. pylori. The results obtained showed that H. pylori was detected in inflamed pulp but not saliva specimens, indicating that an infected root canal may be a reservoir for H. pylori.

Investigation of dental pulp stem cells isolated from discarded human teeth extracted due to aggressive periodontitis

Recently, human dental pulp stem cells (DPSCs) isolated from inflamed dental pulp tissue have been demonstrated to retain some of their pluripotency and regenerative potential. However, the effects of periodontal inflammation due to periodontitis and its progression on the properties of DPSCs within periodontally compromised teeth remain unknown. In this study, DPSCs were isolated from discarded human teeth that were extracted due to aggressive periodontitis (AgP) and divided into three experimental groups (Groups A, B and C) based on the degree of inflammation-induced bone resorption approaching the apex of the tooth root before tooth extraction. DPSCs derived from impacted or non-functional third molars of matched patients were used as a control. Mesenchymal stem cell (MSC)-like characteristics, including colony-forming ability, proliferation, cell cycle, cell surface antigens, multi-lineage differentiation capability and in vivo tissue regeneration potential, were all evaluated in a patient-matched comparison. It was found that STRO-1- and CD146-positive DPSCs can be isolated from human teeth, even in very severe cases of AgP. Periodontal inflammation and its progression had an obvious impact on the characteristics of DPSCs isolated from periodontally affected teeth. Although all the isolated DPSCs in Groups A, B and C showed decreased colony-forming ability and proliferation rate (P < 0.05), the decreases were not consistent with the degree of periodontitis. Furthermore, the cells did not necessarily show significantly diminished in vitro multi-differentiation potential. Only DPSCs from Group A and the Control group formed dentin-like matrix in vivo when cell-seeded biomaterials were transplanted directly into an ectopic transplantation model. However, when cell-seeded scaffolds were placed in the root fragments of human teeth, all the cells formed significant dentin- and pulp-like tissues. The ability of DPSCs to generate dental tissues decreased when the cells were isolated from periodontally compromised teeth (P < 0.05). Again, increased periodontal destruction was not necessarily followed by a decrease in the amount of dentin- and pulp-like tissue formed. These findings provide preliminary evidence that periodontally compromised teeth might contain putative stem cells with certain MSC properties, as long as the vitality of the pulp has not been totally damaged. Whether these cells can serve as a source of autologous multipotent MSCs for clinical regenerative therapies warrants further investigation with larger sample sizes and various types of periodontitis.

IL-17 stimulates the production of the inflammatory chemokines IL-6 and IL-8 in human dental pulp fibroblasts.

To investigate IL-17 expression in human pulpitis and to study the effects of IL-17 on the secretion of the chemokines IL-6 and IL-8 and the related signalling pathways. Samples of human dental pulp tissue were obtained from healthy controls and patients with pulpitis. Cytokine IL-17 messenger RNA (mRNA) expression in the pulp tissue was detected by real-time polymerase chain reaction. In addition, human dental pulp fibroblasts (HDPFs) were stimulated with IL-17. Production of IL-6 and IL-8 was determined by reverse transcriptase-polymerase chain reaction and enzyme-linked immunosorbent assay. Aspects of the nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinases (MAPKs) signalling pathways were examined by Western blot analysis. Increased levels of IL-17 mRNA were found in inflamed dental pulp tissue (pulpitis). Stimulation of dental pulp tissue with IL-17 induced the production of IL-6 and IL-8 in a dose-dependent manner. In addition, IL-17 stimulation resulted in rapid activation of nuclear factor-kappaB (NF-κB), phosphorylation of p38 MAPK, extracellular signal-regulated kinase (ERK) and Jun N-terminal kinase (JNK) in HDPFs. IL-17 may participate in pulp tissue inflammation through chemokine production and NF-κB and MAPKs signalling pathways.

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

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 on 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.

MTA pulpotomy as an alternative to root canal treatment in children's permanent teeth in a dental public health setting

ObjectiveThis prospective clinical study evaluated the success of vital pulpotomy treatment for permanent teeth with closed apices using mineral trioxide aggregates (MTA) in a dental public health setting. MethodsTwenty-seven mature permanent first molars and 2 premolars (in 25 patients) with carious exposure were treated using MTA pulpotomy. Age of patients ranged from 10- to 15-years (mean=13.2±1.74-years). Four trained and calibrated practitioners performed the same clinical procedure for all patients. Following isolation and caries removal, the inflamed pulp tissue was completely removed from the pulp chamber. This was followed by irrigation with 2% sodium hypochlorite. Haemostasis was achieved using a cotton pellet damped in normal saline. A white MTA paste was placed against the pulp orifices. MTA was covered with a damped cotton pellet and a base of IRM. Patients were recalled after 1 day where a glass ionomer liner and a final restoration were placed. Teeth were evaluated clinically and radiographically for up to 47 months. ResultsMean follow-up period for all teeth was 25±14 months. Twenty-six of the 29 teeth were clinically asymptomatic with no evidence of periradicular or root pathology during the follow-up period. The estimated success rate was 90%. Three teeth presented with clinical symptoms of pain and radiographic evidence of periradicular pathology that indicated root canal treatment (RCT) or extraction. ConclusionWhen managing carious pulp exposures of permanent teeth with closed root apices in children, MTA pulpotomy showed a high success rate. Clinical significanceMTA pulpotomy for permanent molars in children is a viable alternative to RCT.

Modulatory Roles of Interferon-γ through Indoleamine 2, 3-dioxygenase Induction in Innate Immune Response of Dental Pulp Cells

IntroductionMarked infiltration of inflammatory cells such as activated T cells producing interferon-γ (IFN-γ) is observed in severe pulpitis. However, the roles of IFN-γ in the innate immune response of dental pulp have not been reported. Indoleamine 2, 3-dioxygenase (IDO) is a regulator of immune responses, and the IDO expression is induced by IFN-γ in many cells whose expression in dental pulp is unknown. The purpose of this study was to determine the role of IFN-γ in the immune response through microbial pattern recognition receptors (PRRs) such as Toll-like receptors or nucleotide-binding oligomerization domain–like receptors on the production of proinflammatory cytokines such as CXCL10 and interleukin (IL)-6 and the expression of IDO in cultured human dental pulp cells (HDPCs). MethodsHDPCs were established from explant cultures of healthy pulp tissues. CXCL10 and IL-6 production was determined using enzyme-linked immunosorbent assay. Confirmation of IDO localization in dental pulp tissues was examined using immunohistochemistry. IDO expression in HDPCs was analyzed by immunoblot. ResultsIFN-γ significantly up-regulated CXCL10 and IL-6 production in the HDPCs stimulated with ligands for PRRs in a concentration-dependent manner. The expression of IDO was detected in inflamed pulp tissue. In addition, IFN-γ in combination with the PRR ligands enhanced IDO expression in HDPCs compared with IFN-γ alone. Moreover, CXCL10 production in IFN-γ–stimulated HDPCs was inhibited by an IDO inhibitor. ConclusionsThis study showed the synergistic effects by IFN-γ on cytokine production and IDO expression in HDPCs, suggesting that IFN-γ may modulate the innate immune response of dental pulp.

Prostaglandin Transporting Protein-mediated Prostaglandin E2 Transport in Lipopolysaccharide-inflamed Rat Dental Pulp

IntroductionThe prostaglandin transporter (Pgt) and multidrug resistance-associated protein (Mrp) 4 are membrane transport proteins that play crucial roles in the transmembrane uptake and/or efflux of prostaglandins (PGs). This study attempted to analyze the protein expression of Pgt and Mrp4 and their involvement in PGE2 efflux transport in lipopolysaccharide (LPS)-inflamed rat incisor pulp tissue. MethodsPulpitis was induced in the upper incisors of Wistar rats by treating them with LPS for 24 hours. The protein expression levels of Pgt, Mrp4, and microsomal PGE synthase (mPGES) were analyzed with immunofluorescent staining. The amount of PGE2 released from the inflamed pulp tissue in the presence or absence of dipyridamole (an Mrp4 inhibitor) was assessed by using an enzyme-linked immunosorbent assay. ResultsDouble immunofluorescence staining revealed that the Pgt, Mrp4, and mPGES immunoreactivity co-localized in CD31-expressing endothelial cells. Moreover, the Mrp4 inhibitor caused a significant decrease in the amount of PGE2 released from the LPS-inflamed pulp (P < .01 at 24 hours). ConclusionPgt, Mrp4, and mPGES expression was detected in the endothelial cells of normal and LPS-inflamed rat incisor pulp tissue, suggesting that these cells are associated with the biosynthesis and transmembrane transport of PGE2. The significant decrease in PGE2 release induced by the Mrp4 inhibitor suggests that Mrp4 contributes to the transport of PGE2 in the transmembrane efflux pathway.

Histopathological Condition of the Remaining Tissues after Endodontic Infection of Rat Immature Teeth

IntroductionRecently, case reports have shown that immature teeth diagnosed with necrotic pulp and periapical periodontitis can be repaired through a regenerative endodontic procedure. True regeneration depends on the presence of stem cells in the remaining vital tissues. The aim of this study was to evaluate the histologic condition of the pulp tissue, root apical papilla, and periapical tissues after inducing endodontic infection in immature rat teeth for different periods. MethodsThis study evaluated 18 first upper rat molars (36 roots). Periapical lesions were induced and were confirmed radiographically, and the animals were divided into 3 groups according to the days of pulp exposure for endodontic infection induction: 30, 60, and 90 days. Histologic analysis was performed in 5 different areas (ie, cervical, middle, and apical root canal thirds; the apical papilla; and the periapex surrounding the apical papilla). ResultsAt 30 days, one third of the specimens still showed vital but intensely inflamed pulp tissue in the apical third and vital apical papilla with varying degrees of inflammation. After 60 days, the results were similar with respect to the apical pulp tissue and apical papilla. Completely necrotic pulp tissue in the space canal and vital apical papilla were observed in about 67% of the cases after 90 days. ConclusionsVital pulp tissue was observed in the apical third until 60 days and in the vital apical papilla until 90 days of infection in a rat model.

Treatment of FGF‐2 on stem cells from inflamed dental pulp tissue from human deciduous teeth

The purposes of this study were to isolate and characterize stem cells from inflamed pulp tissue of human functional deciduous teeth (iSHFD) and to evaluate the influence of fibroblastic growth factor-2 (FGF-2) on the regenerative potential. We successfully isolated mesenchymal stem cells (MSCs) from the inflamed dental pulp tissue of human deciduous teeth and demonstrated that their regenerative potential could be enhanced by the application of FGF-2 (20 ng ml(-1)) during ex vivo expansion. Isolated stem cells expanded in FGF-2 were characterized using a colony-forming assay, proliferation, migration, in vitro differentiation, in vivo ectopic transplantation assay, and gene expression profiling. MSCs isolated from the inflamed pulp tissue of functional deciduous teeth potentially possess the qualities of those from human exfoliated deciduous teeth. FGF-2 applied to iSHFD during expansion enhanced the colony-forming efficiency of these cells, increased their proliferation and migration potential, and reduced their differentiation potential in vitro. However, the ectopic transplantation of iSHFD/FGF-2 in vivo increased the formation of dentin-like material. FGF-2 expansion of stem cells from inflamed pulp tissues of human deciduous teeth can be a good source of stem cells for future clinical applications and a novel way of using discarded inflamed tissues.

The Effect of Full Crown Preparation on Normal and Inflamed Pulp Tissue: An Animal Study

Introduction: Full crown preparation may have adverse effects on pulp tissue. In this study, the effect of full-crown preparation on intact versus inflamed pulp tissue was studied. Methods: Fifteen healthy mature cats were randomly selected for this study. The study was performed on four canine teeth of each cat. Cats were anesthetized and then radiographs were taken from the canine teeth. Class V cavities were prepared in cat canine teeth. Soft decayed dentin was placed on the floor of cavities and sealed. After 1 month, all of the samples prepared for crown fabrication. Before crown preparation, an impression was taken in a custom tray. During crown preparation, the remnants of carious dentin were removed and undercuts were sealed by glass-ionomer. After preparation, self-cured acrylic temporary crowns were fabricated in a direct procedure and cemented permanently by glass-ionomer. One week later, teeth of the opposite jaw were prepared in a similar procedure. After 2 months, vital perfusion performed and the pulp tissue was histologically examined. Results: There was no significant difference between 4 groups, regarding to histologic status of the pulp. In healthy lower jaw, inflammation was the most frequent but in the other groups, necrosis was most frequent. Also, there was no significant difference between the upper jaw and the lower jaw groups regarding to the frequency of necrosis and inflammation. Conclusion: There is no significant difference between intact and inflamed groups regarding the frequency of necrosis and inflammation.

Evaluation of Gelatinases, Tissue Inhibitor of Matrix Metalloproteinase-2, and Myeloperoxidase Protein in Healthy and Inflamed Human Dental Pulp Tissue

IntroductionThe aim of this study was to compare the gelatinolytic activity of matrix metalloproteinase (MMP)-2 and MMP-9 and the expression of tissue inhibitor of matrix metalloproteinase (TIMP)-2 and myeloperoxidase protein (MPO) in clinically healthy human pulp and inflamed pulp tissue specimens. MethodsTwenty dental pulps clinically diagnosed as inflammatory tissues and 20 healthy pulp tissues from enclosed third molars were harvested and evaluated. The gelatinolytic activity for MMP-2 and MMP-9 was assessed by using the zymography technique, TIMP-2 gene expression was evaluated using the enzyme-linked immunosorbent assay, and MPO was determined using the MPO assay. ResultsData showed increased levels of MMP-9, active MMP-2, TIMP-2, and MPO in inflammatory pulp tissues compared with healthy tissues (P < .05). No statistical difference could be observed for pro-MMP-2 (P > .05). ConclusionsAlthough all samples were associated with MMP-2 expression, the active form of this MMP was observed only in inflamed pulps. Inflamed pulps showed an up-regulation of MMP-9, TIMP-2, and MPO.

Incorporation of anti-inflammatory agent into calcium hydroxide pulp capping material: An in vitro study of physical and mechanical properties

The aims of this study were to investigate the release of fluocinolone acetonide from an experimental pulp capping material containing fluocinolone acetonide (PCFA) and compare some physical and mechanical properties with Dycal(®). The PCFA is a hard-setting calcium hydroxide cement composed of 50 mmol/L fluocinolone acetonide. Conditioned media from the setting material was collected for determination of fluocinolone acetonide release by high performance liquid chromatography and pH measurement by pH meter. The setting time, compressive strength, disintegration, and acid soluble arsenic content were measured according to ISO 3107:2004. Dycal(®) was used as control. Fluocinolone acetonide could release at a range of suitable concentrations from PCFA. The pH, setting time, and acid soluble arsenic content of PCFA were significantly higher than those of Dycal(®). The compressive strength and disintegration of PCFA were comparable to control. PCFA may be considered as an alternative in pulp capping of inflamed dental pulp tissue.

Single visit root canal treatment: Review

The main objective of performing root canal therapy is to eliminate bacteria from the infected root canal system or remove inflamed pulp tissue and close it with a biologically acceptable filling material. If this treatment managed well, regardless of the number of visits, it will create a favorable environment for healing. The recent advances in Endodontic technology, attracts the dental practitioners as well as the Endodontist to perform the root canal treatment in one visit. The question that we consider in this review article focuses on the long term prognosis of one-and multiple appointment endodontic therapy for teeth with vital pulp, necrotic pulp, and apical periodontitis .

NaV1.8, but not NaV1.9, is upregulated in the inflamed dental pulp tissue of human primary teeth

To investigate alterations in Na(V) 1.8 and Na(V) 1.9 expression within inflamed dental pulp tissue of human primary teeth. Dental pulp tissue obtained from both normal and inflamed pulps in primary teeth as well as pulps from normal and inflamed permanent teeth was used. The quantity of Na(V) 1.8 and Na(V) 1.9 expression in the dental pulp tissue was investigated using Western blot analysis. General neuron marker (PGP9.5) was used to quantify for neural density, and an increase in metalloproteinase-9 was used to indicate pulpal inflammation in inflamed teeth. Statistically significant differences for each determined parameter between normal and inflamed teeth of both primary and permanent teeth were tested using the Mann-Whitney rank sum test. There was no significant difference in neural density of normal and inflamed dental pulp tissue, although degrees of inflammation were increased in the inflamed dental pulp of both permanent and primary teeth (P < 0.05). Na(V) 1.8 and Na(V) 1.9 expression in inflamed pulps of permanent teeth increased significantly compared with normal permanent teeth (P < 0.05). However, only Na(V) 1.8 expression was increased significantly in the inflamed dental pulp of primary teeth (P < 0.05). Na(V) 1.8 alone may be the therapeutic target for treatment of painful pulpitis in primary teeth.

Cells Isolated from Inflamed Periapical Tissue Express Mesenchymal Stem Cell Markers and Are Highly Osteogenic

Introduction We previously reported the presence of mesenchymal stem/progenitor cells (MSCs) in inflamed pulp tissue. Here we asked whether MSCs also exist in inflamed periapical tissues resulting from endodontic infection. The objectives of this study were to detect the expression of MSC markers in periapical inflammatory tissues and to characterize isolated cells from these tissues. Methods Human periapical inflammatory tissues were collected and processed to detect MSC marker expression by immunohistochemistry. Cells were isolated and tested for cell surface marker expression by using flow cytometry and examined for multiple differentiation potential into osteogenic and adipogenic pathways. In vivo formation of mineralized tissues was assessed in a mouse model. Results Immunohistochemistry showed positive staining for MSC markers STRO-1, CD90, and CD146. Isolated cells at passage 0 appeared as typical fibroblastic cells, and a few cells formed colony-forming unit-fibroblasts (CFU-Fs). After passaging, the CFU-F forming ability diminished dramatically, and the population doubling was up to 26. Flow cytometry data showed that these cells at passage 2 expressed low levels of STRO-1 and CD146 and moderate to high levels of CD90, CD73, and CD105. At passage 6, the levels of these markers decreased. When incubated in specific differentiation medium, cells demonstrated a strong osteogenic but weak adipogenic capacity. After in vivo cell transplantation, mineralized tissues formed in immunocompromised mice. Conclusions Human periapical inflammatory tissues expressed MSC markers, suggesting the presence of MSCs. Isolated cells exhibited typical mesenchymal cell immunophenotype with a capacity to form mineralized matrix in vitro and in vivo.