Pulp Tissue Research Articles

Neuroprotective effects of mesenchymal stromal cells in mouse models of Alzheimer’s Disease: The Mediating role of gut microbes and their metabolites via the Microbiome-Gut-Brain axis

The intricacy and multifaceted nature of Alzheimer’s disease (AD) necessitate therapies that target multiple aspects of the disease. Mesenchymal stromal cells (MSCs) emerge as potential agents to mitigate AD symptoms; however, whether their therapeutic efficacy involves modulation of gut microbiota and the microbiome-gut-brain axis (MGBA) remains unexplored. In this study, we evaluated the effects of three distinct MSCs types—derived from the umbilical cord (UCMSC), dental pulp (SHED), and adipose tissue (ADSC)—in an APP/PS1 mouse model of AD. In comparison to saline control, MSCs administration resulted in a significant reduction of behavioral disturbances, amyloid plaques, and phosphorylated tau in the hippocampus and frontal cortex, accompanied by an increase in neuronal count and Nissl body density across AD-afflicted brain regions. Through 16S rRNA gene sequencing, we identified partial restoration of gut microbial balance in AD mice post-MSCs treatment, evidenced by the elevation of neuroprotective Akkermansia and reduction of the AD-associated Sphingomonas. To examine whether gut microbiota involved in MSCs efficacy in treating AD, SHED with better anti-inflammatory and gut microbiota recovery effects among three MSCs, and another AD model 5 × FAD mice with earlier and more pathological proteins in brain than APP/PS1, were selected for further studies. Antibiotic-mediated gut microbial inactivation attenuated MSCs efficacy in 5 × FAD mice, implicating the involvement of gut microbiota in the therapeutic mechanism. Functional analysis of altered gut microbiota and targeted bile acid metabolism profiling revealed a significant enhancement in bile acid variety following MSCs therapy. A chief bile acid constituent, taurocholic acid (TCA), was orally administered to AD mice and similarly abated AD symptoms. Nonetheless, the disruption of intestinal neuronal integrity with enterotoxin abrogated the ameliorative impact of both MSCs and TCA treatments. Collectively, our findings substantiate that MSCs confer therapeutic benefits in AD within a paradigm that primarily involves regulation of gut microbiota and their metabolites through the MGBA.

First Report of Mango Stem-end Rot Caused by Pestalotiopsis kenyana in Yunnan Province, China.

Stem End Rot (SER) is a devastating post-harvest disease of mango fruits causing severe losses during storage. In 22 July 2023, 31 out of 50 intact mangoes (cv. Sensation) collected from five orchards in Huaping county (26°37'N 101°15') showed typical symptoms of SER after stored for 9 d in room temperature (24-28℃). Initially, small dark brown to black spots appeared around the fruit peduncle, which rapidly expanded through the pulp tissues. The symptomatic mangoes were surface disinfected by 3% NaClO for 30 s after soaking in 75% alcohol for 3 min, and cleaned by sterile water for 3 times. Tissues were cut from the edge of lesions, dried by sterile filter paper, transferred to PDA and cultured at 28 ℃ for 5 d (Tovar-Pedraza et al., 2020). The single-spore isolation method was used to obtain pure culture. Thirty eight isolates presented four distinct kind of morphology on PDA medium. Among them, 11 isolates with same morphology were significantly distinct from common pathogens of SER. The colonies were white and pale yellow on reverse side. Mycelia grew fast and reached the edge of 90 mm Petri dish after cultured for 5d. Pycnidia were black and scattered on the mycelial mats after 15-20 d. Conidia were fusoid, straight to slightly curved, four septa, and brown. Pigmented median cells doliiform, 14.97 - 18.62(16.11 ±0.89)×5.61- 7.28 (6.61±0.51) μm. Apical cell hyaline, subcylindrical; 1-3 tubular transparent apical appendages 12.27 - 16.68 (13.65±3.78)×1.14 - 1.99 (1.59±0.36) μm. Basal cell conical with a truncate base, hyaline, and 1-2 tubulose basal appendages with 2.85 - 7.97 (5.18±1.88)×0.99 - 1.85 (1.38±0.29) μm (n=50). These fungi were described as Pestalotiopsis kenyana. based on morphological characters (Maharachchikumbura et al., 2014) which were different from isolates characterized as other common SER pathogens (Botryosphaeria, Neofusicoccum). Based on morphology, HPSX-4 was selected for further identification. ITS region, tef1-α, β-tub of HPSX-4 were amplified and sequenced (Xun et al., 2023). The sequences were deposited in GenBank (ITS:OR889126, tef1-α:OR913431, β-tub: OR913432). The ITS, tef1-α, β-tub sequence of HPSX-4 showed 100% (525/525)，99.59% (241/242), and 100% (742/742) identity to the P. kenyana CBS442.67 sequences (ITS: NR147549，tef1-α: KM199502, β-tub: KM199395), respectively. HPSX-4 clustered with P. kenyana CBS 442.67 (type strain) based on maximum likelihood method by MEGA 7.0.21(Minh et al., 2013). Pathogenicity test was performed on 12 healthy mangoes (cv. Golek) by placing mycelial plugs around the peduncle and the middle of the fruit by pin-prick method according to Feng et al.(2023). Sterile PDA were used as control (three mangoes). Every inoculated fruit was incubated at 28°C, 95% ± 3% humidity with three replicates for each treatment. The experiment was repeated three times. Typical symptoms of SER were observed. There were no symptoms in the control group. The strain was reisolated and identified as P. kenyana with the method mentioned above which fulfilled Koch's postulates. This is the first report of P. kenyana causing SER disease on Mangifera indica L.. This study expands our understanding of the pathogen range of mango SER which conducive to prevent and control the SER caused by P. kenyana.

Decalcification-free technique on the analysis of dental pulp tissue: histological and immunohistochemical analysis.

Histological techniques are essential for the microscopic study and investigation of the human dental pulp. The aim of this study was to evaluate the impact of decalcification-free technique by examining dental pulp morphology by histological staining with haematoxylin and eosin and immunohistochemistry. The sample consisted of 30 healthy third molars extracted for orthodontic indication, the pulp tissue was obtained by removing the mineralized tissues, separating the enamel and dentine and by marking with a flexible diamond disc on the coronal surface and longitudinal axis of the root. These guides made it possible to separate the fragments and obtain the pulp tissue for fixation and staining with H&E and subsequent immunohistochemistry with CD34 and S-100 antibodies. The technique showed preservation of pulp morphology with adequate preservation of microscopic structures. No alterations in tissue viability were observed. The staining allowed an accurate assessment of vascular and nervous components by means of CD34 and S-100 markers, respectively. This technique allows preservation of pulp tissue, maintaining viable tissue for histological analysis and immunohistochemistry tests, as well as reducing sample processing time.

Role of Umbilical Cord Mesenchymal Derived Exosomes in Diseases

Stem cells are divided into embryonic stem cells and adult stem cells. Mesenchymal stem cells (MSCs) are one of the most important adult stem cells. These cells possess characteristic plastic adhesion properties, the ability to differentiate into osteoblasts, chondrocytes and adipocytes in vitro, are positive for CD73, CD90 and CD105, major histocompatibility complex class II, and negative for CD11b, CD14, CD31, CD34 and CD45. MSCS can be isolated from different sources, such as umbilical cord, umbilical cord blood, bone marrow (BM), adipose tissue, cervical tissue, placenta, skeletal muscle tissue, liver tissue, dental pulp, synovium, saphenous vein, lung and dermal tissue and periodontal ligament. They have many abilities, such as the ability to differentiate, expand in vitro, produce nutrients and regulate immunity. Therefore, bone marrow mesenchymal stem cells can help in tissue repair and treatment, such as diabetes, cardiovascular diseases, diseases of the liver, lung, kidney, nervous system, and other systems, and of course, bone. As a noninvasive method, there is no ethical issues, low immunogenicity, self-renewal ability faster, more stable, doubling time proliferation ability is higher, compared with other sources, the treatment of human umbilical cord MSC is based on cells and regenerative medicine preferred candidates. However, hucMscs have relative limitations in maintaining biological activity, quantifying bioactive substances, and clinical therapeutic logistics. Therefore, it seems necessary to find a cell-free method with the same output and efficacy. Exosomes are one of the members of extracellular vesicles, and due to their many biological activities and cell communication, they have attracted the attention of researchers as a new strategy for cell-based cell-free therapies. In the study of HUCMSCexo, all the advantages of HUCMSC, such as the therapeutic factor transfer of low immunogenicity HUCMSC, the prominent self-renewal and immunomodulatory properties have been reported to be conserved. In addition, no tumorigenic outcome was found in these studies. Therefore, this article reviews the application of HUCMSC-EXO in different diseases.

MiR-143-5p regulates the proangiogenic potential of human dental pulp stem cells by targeting HIF-1α/RORA under hypoxia: A laboratory investigation in pulp regeneration.

Angiogenesis is a key event in the successful healing of pulp injuries, and hypoxia is the main stimulator of pulpal angiogenesis. In this study, we investigated the effect of hypoxia on the proangiogenic potential of human dental pulp stem cells (hDPSCs) and the role of miR-143-5p in the process. Human dental pulp stem cells were isolated, cultured and characterized invitro. Cobalt chloride (CoCl2) was used to induce hypoxia in hDPSCs. CCK-8 and Transwell assays were used to determine the effect of hypoxia on hDPSCs proliferation and migration. Quantitative real-time polymerase chain reaction (qRT-PCR), Western blotting (WB) and ELISA were performed to assess the mRNA and protein levels of HIF-1α and angiogenic cytokines in hDPSCs. The effect of hypoxia on hDPSCs proangiogenic potential was measured invitro using Matrigel tube formation and chick chorioallantoic membrane (CAM) assays. Recombinant lentiviral vectors were constructed to stably overexpress or inhibit miR-143-5p in hDPSCs, and the proangiogenic effects were assessed using qRT-PCR, WB, and tube formation assays. miR-143-5p target genes were identified and verified using bioinformatics prediction tools, dual-luciferase reporter assays and RNA pull-down experiments. Finally, a subcutaneous transplantation model in nude mice was used to determine the effects of hypoxia treatment and miR-143-5p overexpression/inhibition in hDPSCs in dental pulp regeneration. Hypoxia promotes hDPSCs proliferation, migration and proangiogenic potential. The invivo experiments showed that hypoxia treatment (50 and 100 μM CoCl2) promoted pulp angiogenesis and dentine formation. In contrast to the levels of proangiogenic factors, miR-143-5p levels decreased with increasing CoCl2 concentration. miR-143-5p inhibition significantly promoted proangiogenic potential of hDPSCs, whereas miR-143-5p overexpression inhibited angiogenesis invitro. Dual-luciferase reporter assay identified retinoic acid receptor-related orphan receptor alpha (RORA) as an miR-143-5p target gene in hDPSCs. RNA pull-down experiments demonstrated that HIF-1α and RORA were pulled down by biotin-labelled miR-143-5p, and the levels of HIF-1α and RORA bound to miR-143-5p in the hypoxia group were lower than those in the normoxia group. Inhibition of miR-143-5p expression in hDPSCs promoted ectopic dental pulp tissue regeneration. CoCl2-induced hypoxia promotes hDPSCs-driven paracrine angiogenesis and pulp regeneration. The inhibition of miR-143-5p upregulates the proangiogenic potential of hDPSCs under hypoxic conditions by directly targeting HIF-1α and RORA.

Characteristics of inflammatory mediators in dental pulp inflammation and the potential for their control

Dental pulp is a mesenchymal connective tissue located inside the rigid encasement of the dentin. When bacteria or bacterial products invade the dental pulp, inflammation known as pulpitis is induced in this tissue. Various mediators produced during the course of pulpitis profoundly modify the pathophysiology of the inflammation. Typical mediators include cytokines, chemokines, nitric oxide, reactive oxygen species, matrix metalloproteinases, proteases, neutrophil extracellular traps, neuropeptides, and eicosanoids. Controlling these mediators may potentially lead to the healing of pulpitis and the preservation of pulp tissue. This review discusses these mediators and further explores the possibility of controlling them.

Histological Changes in Dental Pulp During the Aging Process: Implications for Endodontic Treatment

on the results of endodontic treatment. Knowledge of these changes is essential in order to design treatment strategies that allow aging people a life with constant dental health. Objective: The objective of this study sought to perform an analysis of the histological changes that occur within dental pulp as a result of aging. Study Design: This is a cross-sectional study. Duration and Place of the Study: This study was conducted at Department Anatomy of General Hospital and Research Centre, Peshawar, from 3rd November 2022 to 2nd December 2023. Material and Methods: A total of 220 patients aged between 20-80 years, were admitted to this survey. According to age, they were classified into 20-29 years (n=41), 30-39 years (n=39),40-49 years (n=48), 50-59 years (n=45 ) and 60 -80 years( n=47). Extraction of dental pulp samples Pulp tissues were harvested from teeth that had been extracted for non-dental reasons. Histological analysis for cellularity, vascularity and fibrous content of the pulp tissue. Results: A total of 220 patients aged between 20 and 80 Years were included in this study. The biggest group of people was participants 40-49 years old (21.8%), and the smallest one is for 30-39-year-olds with (17.7%). The study found that Participants of the age groups 20–29 years showed a mean cellularity (1500 cells/mm²), with standard deviation of ±200, while those in the 60-80 years group had the lowest mean cellularity at 800 cells/mm² with a standard deviation of ±160. Conclusion: The histological changes in dental pulp with ageing have as consequences implications on endodontic treatment. Keywords: Dental Pulp, Histological Changes, Endodontic Treatment Implications

Intrapulpal anesthesia in endodontics: an updated literature review.

Effective pain management is crucial for the successful performance of various endodontic procedures. Painless treatments are made possible by anesthetizing the tooth to be treated using various nerve-block techniques. However, certain circumstances necessitate supplemental anesthetic techniques to achieve profound anesthesia, especially in situations involving a "hot tooth" in which intrapulpal anesthesia (IPA) is employed. IPA is a technique that involves the injection of an anesthetic solution directly into the pulp tissue and is often utilized as the last resort when all other anesthetic techniques have been unsuccessful in achieving complete pulpal anesthesia. This review focuses on the IPA procedure and the factors that influence its success. Additionally, the advantages, limitations, disadvantages, and future directions of IPA are discussed.

Comparision of interleukin-1β concentrations in posttreatment endodontic disease and other pulpal and periapical conditions - A clinical study.

To evaluate interleukin (IL)-1β concentrations in periapical tissue fluid (PTF) in persistent apical periodontitis requiring endodontic retreatment and to compare the levels of IL-1β with chronic apical periodontitis, symptomatic irreversible pulpitis (SIP), normal pulpal, and periapical tissues. The patients were selected based on inclusion and exclusion criteria and divided into 4 groups based on the pulpal and periapical status: Posttreatment endodontic diseases (PTED): Teeth with PTED due to failed primary root canal treatment having periapical radiolucency. PNAP: Teeth requiring root canal treatment due to pulpal necrosis having periapical radiolucency. SIP: Teeth with symptoms of SIP with healthy periapical tissues). Intentional root canal treatment (IRCT): Teeth requiring IRCT (healthy pulp and periapical tissues). The access cavity was redefined and the preexisting filling was removed using H-files. The root canals were minimally enlarged followed by collection of PTF using paper points, in the case of group PTED. For groups PNAP, SIP, and IRCT, conventional access cavity preparation was done followed by enlargement of canals till 20, 0.02. PTF was collected using 15, 0.02 size absorbent points 2 mm beyond the apex. Levels of IL-1β was assessed by enzyme-linked immunosorbent assay. A statistically significant difference was seen in levels of IL-1β in all the groups. The highest concentration was seen in group PTED (85.07 ± 11.57 pg/mL) followed by group PNAP (37.60 ± 10.94 pg/mL), group SIP (8.40 ± 1.99 pg/mL), and the least was seen in group IRCT (3.47 ± 1.36 pg/mL). The levels of IL-1β were highest in PETD cases followed by PNAP, SIP, and IRCT. This indicates the severity of inflammation in PETD cases as compared to other endodontic diseases.

The potential of exosomes from adipose-derived stromal-vascular fraction in Increasing Migration Activity of Human Dental Pulp Stromal Cells (in vitro study)

BackgroundMigration of dental pulp stromal cells (DPSCs) significantly responds to wound healing after pulp injury. Deriving from low compliance characteristics, pulp tissue regeneration is challenging and depends on the microenvironmental signals. Exosomes can maintain and carry bioactive proteins that are crucial in cell communication. Adipose tissue-derived stromal vascular fraction (AD-SVF), a heterogeneous group of progenitor cells, is a promising source of exosomes. ObjectiveDiscover the impact of exosomes derived from an adipose-derived stromal-vascular fraction (AD-SVF Exo) on human dental pulp stromal cells (hDPSCs) migration. Methods: In-vitro design involving AD-SVF Exo applied to hDPSCs cultivated until 80% confluence and 3rd-4th passage. AD-SVF Exo isolation through size exclusion chromatography (SEC). The AD-SVF Exo was characterized using Nanoparticle Tracking Analysis (NTA) and flow cytometry assays. hDPSCs were exposed to AD-SVF Exo (0% as the control group, 0.1%, and 1% as the experimental group), subjected to a scratch wound assay, and observed at 6, 24, and 48 h. ResultshDPSCs cultured expressed mesenchymal stem cell mesenchymal stem cell (MSC) markers and formed loose colonies with characteristic spindle-shaped morphology. AD-SVF Exo consisted of marker proteins CD9 and CD63, and NTA measurement demonstrated a diameter of 103 ± 24 nm in diameter with 1,6 x 108 particles/ml. Based on scratch assay, hDPSCs migration activity improved by reduced wound area in experimental groups. Data analyzed utilizing the Friedman (p < 0.001), and Kruskal Wallis (p < 0.05) test indicated differences in wound area after exposure of 0.1 % and 1 % AD-SVF Exo and observed at 6, 24, and 48 h. ConclusionAccording to the findings of this research, AD-SVF Exo successfully enhances the wound healing capabilities of hDPSCs by improved migration activity, with the highest result found in 0.1% AD-SVF Exo.

LESION STERILISATION AND TISSUE REPAIR OF PRIMARY TEETH

BACKGROUND Lesion sterilization and tissue repair is also known as non-instrumental endodontic therapy. It involves the use of combination of antibiotics drugs on infected pulp tissue and root canals after getting access to the root canal orifices of the primary teeth. Various combination of antibiotics had been used by some dentists with macrogol , polyethylene glycol, propylene glycol, normal saline or sterile water as the solvent or vehicle used. METHODS An electronic literature search in Science direct and Google was done in December, 2023 using the Population, Concept and Context framework. Search terms and keywords were combined by Boolean operators. Two independent investigators screened titles and abstracts of publications on lesion sterilization and tissue repair of primary teeth. Original research articles, case report, case series with accessible full text were included for review, while review articles, systematic reviews, viewpoints, books, letters, thesis, editorials, book chapters, dissertations and perspectives were among articles excluded during screening. RESULTS One case report was identified from Morocco, a case series from Nigeria and randomized controlled trial from Egypt respectively. CONCLUSIONS Lesion sterilization and tissue repair or non-instrumental endodontic therapy can be a treatment option for primary teeth with infected pulp and root canals .More studies from diverse ethnic population in Africa countries will fill the gaps in knowledge and add to the existing literature.

Ginsenoside RB1 Influences Macrophage–DPSC Interactions in Inflammatory Conditions

Unresolved inflammation and tissue destruction are supposed to underlie the failure of dental pulp repair. As crucial regulators of the injury response, dental pulp stem cells (DPSCs) play a key role in pulp tissue repair and regeneration. M2 macrophages have been demonstrated to induce osteogenic/odontogenic differentiation of DPSCs. Ginsenoside Rb1 (GRb1) is the major component of ginseng and manifested an anti-inflammatory role by promoting M1 macrophage polarised into M2 macrophage in inflammatory disease. However, whether GRb1 facilitates odontogenic differentiation of DPSCs via promoting M2 macrophage polarisation under inflammatory conditions has yet to be established. Human monocyte leukemic cells (THP-1) differentiated macrophages were induced into M1 subsets and then treated with GRb1. After that, the conditioned medium was added to DPSCs. The cell co-cultured system was then subjected to odontogenic differentiation in osteogenic media. Effects of GRb1 on human dental pulp stem cells' (hDPSCs') osteogenic/odontogenic differentiation under inflammatory conditions were assessed by alkaline phosphatase (ALP) staining, Alizarin Red S (ARS) staining, and quantitative polymerase chain reaction testing. Results demonstrated that GRb1 could facilitate the polarisation of macrophages from the M1 subtype to the M2 subtype. Conditioned medium from GRb1 + M1 macrophages, in comparison with M1 macrophages, may markedly increase the gene expression of ALP, DSPP, and DMP1. Moreover, ALP and ARS staining uncovered that the osteogenic/odontogenic differentiation ability of hDPSCs was strengthened in the M1 + GRb1 co-culture group. GRb1 plays a crucial role in the inflammatory response and reparative dentine formation after dental pulp injury. Findings show that GRb1 modulates the interaction between macrophages and DPSCs during inflammation. The current study discusses modifications of deep caries therapy.

Preserving pulp vitality for teeth with post-vital pulp therapy symptoms by retrying pulp-preserving procedures: A retrospective clinical study

Background/purposeThe occurrence of post-vital pulp therapy (VPT) symptoms is perplexing for dentists, and root canal treatment (RCT) is preferred for such conditions. Furthermore, managing post-VPT symptoms, rather than performing RCT, would preserve pulp vitality and enhance VPT outcomes. This study aimed to evaluate the efficacy of VPT retrials in preserving pulp vitality and substituting RCT in teeth with post-VPT symptoms. Materials and methodsVPT was performed on the exposed pulp during caries removal in symptomatic and asymptomatic teeth. VPTs were repeated in teeth with post-VPT symptoms. This study screened multi-time-practiced VPT cases from a VPT-performed data pool. The presence of vital pulp tissue after minimized pulp resection (MPR) was a prerequisite for substituting RCT with VPT retrials. A total of 22 cases from 19 patients were included in this study. MPR was introduced to maximize the preservation of the vital pulp. ResultsAfter performing VPT, post-VPT symptoms occurred in pre-VPT asymptomatic teeth, or pre-VPT symptoms were modified in teeth with pre-VPT symptoms. The rate of pre-VPT irreversible pulpitis (IP), comprising symptomatic/asymptomatic IP, was 81.68%. The most prevalent post-VPT symptom was heightened sensitivity to thermal stimuli (68.2%), followed by spontaneous pain (45.5%). The post-VPT IP was 63.6%. VPT retrials resolved 90.9% of cases with post-VPT symptoms. ConclusionVPT retrials using MPR could enhance VPT outcomes and be a viable alternative to RCT for teeth with post-VPT symptoms.

Association between pulp stones and systemic diseases: A case-control study

Introduction: Pulp stones (PS) are calcifications commonly found in the pulp tissue that may be associated with systemic diseases. Objective: To evaluate the association between PS and systemic diseases. Methods: A case-control study with the inclusion of individuals from 18 to 65 years of age, of both sexes. Analysis was made of 1047 digital panoramic radiographs. The controls could not have any teeth with PS; the cases were the contrary. A questionnaire comprising demographic, habit, and general health (diabetes, problems with blood vessels, altered cholesterol level, heart attack, kidney or gallbladder stone, arthritis, or autoimmune disease, and for women, endometriosis, and ovarian cyst). Data were submitted to the Student's t-test to identify differences between groups about sex and age. The Chi-square test was applied to the cross-tabulation. The analyses were performed using SPSS®, version 25.0, with a 5% significance level. Results: 490 patients participated (242 cases and 248 controls). There was no difference between groups for the sex (p=0.966) and age (p=0.186). Only “kidney stone” was associated with the case group (p=0.001), being almost three times higher when compared to the control group. No significant differences were found in females about the presence or absence of PS (p&gt;0.05). Conclusion: In this research, it is suggested the existence of an association between kidney stones and the presence of pulp stones.

Effect of four direct pulp capping agents on human dental pulp tissue.

Direct pulp capping (DPC) is a vital pulp therapy, wherein accidental or carious pulp exposures can be capped with various materials to induce reparative dentine formation. One of the major factors that determine the success of direct pulp capping procedures is the material used. Therefore, it is of interest to evaluate and compare the efficacy of a new material, Tristrontium aluminate in comparison with the widely used materials such as ProRoot MTA, Biodentine & TheraCal LC. Hence, 40 premolars scheduled for extraction for orthodontic treatment, were equally divided into 4 groups and iatrogenic DPC was done using one of the study materials. The premolars were then extracted after 90 days & assessed for the formation of Dentine Bridge and pulpal response elicited by the materials using CBCT and histopathological analysis. All the materials tested in the study were successful in inducing dentine bridge formation & maintaining pulp vitality. Thus, the novelty of Tristrontium aluminate for potential applications in future is eminent.

How does orthodontic tooth movement influence the dental pulp? RNA-sequencing on human premolars.

The objective of this study is to analyse the gene expression profile of the dental pulp (DP) of human premolars subjected to 7 and 28 days of orthodontic force (OF) in vivo by using RNA sequencing. The maxillary and mandibular DP were additionally compared. Healthy patients requiring orthodontic premolar extractions were randomly assigned to one of the three groups: control (CG) where no OF was applied, 7 and 28 days, where premolars were extracted either 7 or 28 days after the application of a 50-100 g OF. Total RNA was extracted from the DP and analysed via RNA-seq. Differentially expressed genes (DEGs) were identified using a false discovery rate and fold change threshold of <0.05 and ≥1.5, respectively. Functional analysis was performed. After 7 days of OF, pulp reaction indicates immune response, hypoxia, DNA damage and epigenetic regulation. After 28 days, cell adhesion, migration, organization and tissue repair are evident. The maxillary and mandibular pulp tissues react differently to OF. The maxilla exhibits minimal alterations, mostly related to immune response at 7 days and tissue repair at 28 days, whereas the mandible shows mostly DNA damage and epigenetic regulation at 7 days and return to the original state at 28 days. This study demonstrates that the early reaction of the DP to OF is marked by immune response, hypoxia and DNA damage. In contrast, after 28 days, cell adhesion, migration, organization, tissue repair and dentine formation are observed. Maxillary and mandibular premolars react differently to OF: although the maxilla exhibits minimal alterations at both time points, the mandible mostly shows DNA damage, epigenetic regulation, and immune response at 7 days. These disparities could stem from different blood supplies or the lower maxillary bone density, potentially triggering faster biological changes. Our findings provide insights into the gene regulatory networks modulating DP response to OF.

BRF1 promotes the odontogenic differentiation of dental pulp stem cells in pulpitis by inducing autophagy

ObjectiveWhile post-transcriptional modifications play a pivotal role in the autophagy regulation, studies on dental pulp disease are limited. This study investigated the effect of BRF1 on autophagy in inflamed pulp tissue and human dental pulp stem cells (hDPSCs). MethodsImmunohistochemical analysis was used to examine BRF1 expression, autophagy levels, and dentinogenic markers in normal and inflamed pulp. The presence of autophagosomes was observed by transmission electron microscopy. Primary hDPSCs were treated with 1 μg/mL lipopolysaccharide (LPS) for different lengths of time. The expression of BRF1 and autophagy makers was determined by Western blotting. BRF1 knockdown and 3 MA treatment were employed to assess changes in autophagy and dentinogenic differentiation. Double immunofluorescence staining was performed to co-localize BRF1 with LC3B in pulp tissue. ResultsThe expressions of BRF1, LC3, DMP1, and DSP were significantly elevated in the inflamed pulp. LPS enhanced the protein production of IL-6, BRF1, LC3, and Beclin-1 from 6 h to 24 h after the treatment. BRF1 knockdown reduced the ratio of LC3-II/LC3-I and the differentiation ability of hDPSCs, while 3 MA inhibited LPS-mediated dentinogenic differentiation. Double-labeling revealed that BRF1 co-localized with LC3B in inflamed pulp. ConclusionThis study demonstrated that BRF1 promoted autophagy activation and odontogenic differentiation in pulpitis.

To Evaluate and Compare Platelet-rich Fibrin and Mineral Trioxide Aggregate as Direct Pulp Capping Agents in Primary Molars: A Randomized Prospective Clinical Study.

This study aimed to evaluate and compare the clinical and radiographic success of platelet-rich fibrin (PRF) and mineral trioxide aggregate (MTA) as direct pulp capping (DPC) agents in primary molars. In this study, 50 primary first and second molars from healthy children aged 5-9 years requiring pulp therapy were randomly allocated into two groups. In the PRF group, after coronal pulp removal and hemostasis, the remaining pulp tissue was covered with PRF preparation. In the MTA group, after coronal pulp removal and hemostasis, MTA was placed, followed by a zinc oxide eugenol (ZOE) base and glass ionomer cement (GIC) in both groups. Clinical and radiographic evaluations were undertaken at 1-, 3-, 6-, 9-, and 12-month intervals. By the end of the 12th month, the overall success rate was 82.6% in the PRF group, whereas it was 61.9% in the MTA group. Platelet-rich fibrin can be used successfully as an appropriate alternative material in DPC of primary teeth when compared with MTA. Tiwari T, Tyagi P, Tiwari S, et al. To Evaluate and Compare Platelet-rich Fibrin and Mineral Trioxide Aggregate as Direct Pulp Capping Agents in Primary Molars: A Randomized Prospective Clinical Study. Int J Clin Pediatr Dent 2024;17(S-1):S25-S29.

A review of tissue engineering in regenerative endodontic treatment

Background: Regenerative endodontic treatments are classified based on approach in the procedures and principles. One is cell-free approach that involves a revitalization procedure to achieve continued root growth while the other is cell-based approach which involves pulp/dentin regeneration through isolation and ex vivo expansion of stem cells seeded in the scaffold and then transplanted into the canal space. Technically, the cell-free approach is simpler than cell-based approach because the former does not concern about external stem cell isolation and culture. Currently, the gold standard and the one that has been clinically performed is cell-free approach. Cell-based approach is still not a standard because currently the cell-based approach is still in the clinical trial stage. Purpose: to evaluate the biological basis and clinical protocols recently used in regenerative endodontic treatment and discuss potentially future treatment approaches. Review: The literature review was searched in PUBMED with the keywords: immature permanent teeth, pulp revascularization, stem cells and regenerative endodontics. The regenerative endodontic treatments with various procedures and techniques result in a significant increase in root length and dentinal wall thickness. Stimulation of stem cells in apical root canal system is required to induce tissue formation and continued root maturation. Conclusion: The success of regenerative endodontic therapy relies on the development of a technique that enables clinicians to create functional pulp tissue within cleaned and shaped root canal systems. It is hoped that further research studies are required to define advantages and limitations of cell-free and cell-based approach.

Confirmación del diagnóstico clínico-radiográfico de pulpitis reversible e irreversible a través del método histopatológico, en pacientes de 3 a 8 años que acuden a la UEO. Antecedentes, estado actual y prospectiva en la SEDENA

Objective: To determine if the histopathological study is associated with the clinical-radiographic diagnosis of reversible and irreversible pulpitis, in patients from 3 to 8 years of age who come to the UEO. Methodology: Conventional clinical diagnostic methods were used for the clinical-radiographic evaluation of reversible and irreversible pulpitis; Likewise, an excisional biopsy of the pulp tissue of 41 dental organs that presented pulp pathology was performed using dentin cutting spoons. In the research laboratory of the Universidad Autónoma del Estado de México (UAEM), using light microscopy, the pulp tissue was studied by a stomatologist specialist and the histopathological diagnosis of the biopsies was established. Results: The McNemar statistical test (comparison of proportions for related samples) resulted in no statistically significan difference (p&gt;0.05, 95 % CI) between the presumptive diagnosis and the confirmatory diagnosis. Limitations: No limitations were considered. Value: An alternative method can be used in places where all means are not available. Conclusions: The histopathological diagnosis confirmed the clinical-radiographic diagnosis in this sample, so it is suggested to use all conventional diagnostic methods to establish a more accurate diagnosis and therefore a better treatment.