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Journal of Dental Research Jun 2024Located at the interface of the dentin-pulp complex, the odontoblasts are specialized cells responsible for dentin synthesis and nociceptive signal detection in response...
Located at the interface of the dentin-pulp complex, the odontoblasts are specialized cells responsible for dentin synthesis and nociceptive signal detection in response to external stimuli. Recent studies have shown that the mechanosensitive ion channel PIEZO1 is involved in bone formation and remodeling through the influx of calcium ions, and it is abundantly expressed in odontoblasts. However, the specific role of PIEZO1 in reactionary dentinogenesis and the underlying mechanisms remain elusive. In this study, we found intense PIEZO1 expression in the plasma membrane and cytoplasm of odontoblasts in healthy human third molars, mouse mandibular molars, and human odontoblast-like cells (hOBLCs). In hOBLCs, PIEZO1 positively regulated DSPP, DMP1, and COL1A1 expression through the Ca/PI3K-Akt/SEMA3A signaling pathway. In addition, exogenous SEMA3A supplementation effectively reversed reduced mineralization capacity in -knockdown hOBLCs. In vivo, Piezo1 expression peaked at day 7 and returned to baseline at day 21 in a wild-type mice dentin injury model, with Sema3a presenting a similar expression pattern. To investigate the specific role of PIEZO1 in odontoblast-mediated reactionary dentinogenesis, mice with a conditional knockout of in odontoblasts were generated, and no significant differences in teeth phenotypes were observed between the control and conditional knockout () mice. Nevertheless, mice exhibited reduced reactionary dentin formation and decreased Sema3a and Dsp positive staining after dentin injury, indicating impaired dental pulp repair by odontoblasts. In summary, these findings suggest that PIEZO1 enhances the mineralization capacity of hOBLCs in vitro via the Ca/PI3K-Akt/SEMA3A signaling pathway and contributes to reactionary dentinogenesis in vivo.
PubMed: 38910430
DOI: 10.1177/00220345241257866 -
Dental Materials : Official Publication... Jun 2024Silicon-releasing biomaterials are widely used in the field of dentistry. However, unlike bone, very little is known about the role of silicon on dental tissue formation...
OBJECTIVES
Silicon-releasing biomaterials are widely used in the field of dentistry. However, unlike bone, very little is known about the role of silicon on dental tissue formation and repair. This study investigates the influence of silicic acid on the survival, differentiation and mineralizing ability of human dental pulp stem cells (hDPSCs) in 3D pulp-like environments METHODS: Dense type I collagen hydrogels seeded with hDPSCs were cultured over 4 weeks in the presence of silicic acid at physiological (10 μM) and supraphysiological (100 μM) concentrations. Cell viability and proliferation were studied by Alamar Blue and live/dead staining. The collagen network was investigated using second harmonic generation imaging. Mineral deposition was monitored by histology and scanning electron microscopy. Gene expression of mineralization- and matrix remodeling-associated proteins was studied by qPCR.
RESULTS
Presence of silicic acid did not show any significant influence on cell survival, metabolic activity and gene expression of key mineralization-related proteins (ALP, OCN, BSP). However, it induced enhanced cell clustering and delayed expression of matrix remodeling-associated proteins (MMP13, Col I). OPN expression and mineral deposition were inhibited at 100 μM. It could be inferred that silicic acid has no direct cellular effect but rather interacts with the collagen network, leading to a modification of the cell-matrix interface.
SIGNIFICANCE
Our results offer advanced insights on the possible role of silicic acid, as released by pulp capping calcium silicates biomaterials, in reparative dentine formation. More globally, these results interrogate the possible role of Si in pulp pathophysiology.
PubMed: 38908960
DOI: 10.1016/j.dental.2024.06.021 -
BMC Oral Health Jun 2024A pulp stone is a calcified mass that develops in the dental pulp of any tooth. Despite many studies examining the relationship between pulp stone formation and non-oral...
BACKGROUND
A pulp stone is a calcified mass that develops in the dental pulp of any tooth. Despite many studies examining the relationship between pulp stone formation and non-oral factors, the methods used in these studies have been unable to explain the exact role of these factors alone as distinct from probable effects within the oral cavity environment. Considering that totally unerupted (impacted or developing) teeth are unexposed to the oral cavity's environmental and functional conditions, they provide a more suitable material for studying the effects of these non-oral factors on pulp stone formation. This research study aimed to investigate pulp stones in unerupted teeth and the associated factors in a Saudi subpopulation.
METHODS
The study included 644 cone-beam computed tomography images, with 496 (50.9%) maxillary and 479 (49.1%) mandibular teeth. Of the investigated patients, 293 (45.5%) were men, and 351 (54.5%) were women. The age range was 15-76 years. A chi-square test was used to investigate the associations between pulp stones and age, gender, and history of systemic disease and chronic medication use.
RESULTS
Pulp stones in unerupted teeth were present in 24.2% of the examined dental jaws and 18.6% of the examined teeth. There was no statistically significant relationship between pulp stones and gender (p > 0.05). A significantly greater percentage of pulp stones were found with increasing age (p = 0.000). Additionally, a significantly increased number of pulp stones was observed in patients with systemic diseases and chronic medications (p < 0.05).
CONCLUSIONS
The results support the idea that pulp stones can be present in any type of unerupted tooth. This study provides additional evidence of the increased incidence of pulp stones with age, systemic disease, and chronic medications.
Topics: Humans; Cone-Beam Computed Tomography; Female; Adult; Male; Retrospective Studies; Adolescent; Middle Aged; Dental Pulp Calcification; Young Adult; Aged; Tooth, Unerupted; Saudi Arabia; Age Factors
PubMed: 38907221
DOI: 10.1186/s12903-024-04503-3 -
Archives of Oral Biology Sep 2024The aim of this study was to explore the effect and mechanism of programmed cell death ligand 1 (PD-L1) in promoting the proliferation and...
Overexpression of programmed cell death ligand 1 reduces LPS-induced inflammatory cytokine upregulation and enhances osteo/odontogenic-differentiation of human dental pulp stem cells via upregulation of CCCTC-binding factor.
OBJECTIVE
The aim of this study was to explore the effect and mechanism of programmed cell death ligand 1 (PD-L1) in promoting the proliferation and osteo/odontogenic-differentiation of human dental pulp stem cells (hDPSCs) by mediating CCCTC-binding factor (CTCF) expression.
DESIGN
The interaction between PD-L1 and CTCF was verified through co-immunoprecipitation. hDPSCs transfected with PD-L1 overexpression and CTCF knockdown vectors were treated with lipopolysaccharide or an osteogenic-inducing medium. Inflammatory cytokines and osteo/odontogenic-differentiation related genes were measured. Osteo/odontogenic-differentiation of hDPSCs was assessed using alkaline phosphatase (ALP) and alizarin red S staining.
RESULTS
Overexpression of PD-L1 inhibited LPS-induced pro-inflammatory cytokine upregulation, cell proliferation, ALP activity, and calcium deposition in hDPSCs and elevated the expression of osteo/odontogenic-differentiation related genes; however, such expression patterns could be reversed by CTCF knockdown. Co-immunoprecipitation results confirmed the binding of PD-L1 to CTCF, indicating that PD-L1 overexpression in hDPSCs increases CTCF expression, thus inhibiting the inflammatory response and increasing osteo/odontogenic-differentiation of hDPSCs.
CONCLUSION
PD-L1 overexpression in hDPSCs enhances the proliferation and osteo/odontogenic-differentiation of hDPSCs and inhibit the inflammatory response by upregulating CTCF expression.
Topics: Humans; Dental Pulp; B7-H1 Antigen; Up-Regulation; Cytokines; Cell Differentiation; Osteogenesis; Cell Proliferation; CCCTC-Binding Factor; Stem Cells; Lipopolysaccharides; Odontogenesis; Cells, Cultured; Real-Time Polymerase Chain Reaction; Blotting, Western; Immunoprecipitation; Alkaline Phosphatase
PubMed: 38905870
DOI: 10.1016/j.archoralbio.2024.106031 -
JMIRx Med Jun 2024Information about the range of Hounsfield values for healthy teeth tissues could become an additional tool in assessing dental health and could be used, among other...
BACKGROUND
Information about the range of Hounsfield values for healthy teeth tissues could become an additional tool in assessing dental health and could be used, among other data, for subsequent machine learning.
OBJECTIVE
The purpose of our study was to determine dental tissue densities in Hounsfield units (HU).
METHODS
The total sample included 36 healthy children (n=21, 58% girls and n=15, 42% boys) aged 10-11 years at the time of the study. The densities of 320 teeth tissues were analyzed. Data were expressed as means and SDs. The significance was determined using the Student (1-tailed) t test. The statistical significance was set at P<.05.
RESULTS
The densities of 320 teeth tissues were analyzed: 72 (22.5%) first permanent molars, 72 (22.5%) permanent central incisors, 27 (8.4%) second primary molars, 40 (12.5%) tooth germs of second premolars, 37 (11.6%) second premolars, 9 (2.8%) second permanent molars, and 63 (19.7%) tooth germs of second permanent molars. The analysis of the data showed that tissues of healthy teeth in children have different density ranges: enamel, from mean 2954.69 (SD 223.77) HU to mean 2071.00 (SD 222.86) HU; dentin, from mean 1899.23 (SD 145.94) HU to mean 1323.10 (SD 201.67) HU; and pulp, from mean 420.29 (SD 196.47) HU to mean 183.63 (SD 97.59) HU. The tissues (enamel and dentin) of permanent central incisors in the mandible and maxilla had the highest mean densities. No gender differences concerning the density of dental tissues were reliably identified.
CONCLUSIONS
The evaluation of Hounsfield values for dental tissues can be used as an objective method for assessing their densities. If the determined densities of the enamel, dentin, and pulp of the tooth do not correspond to the range of values for healthy tooth tissues, then it may indicate a pathology.
PubMed: 38904484
DOI: 10.2196/56759 -
Cureus May 2024Silver diamine fluoride (SDF) has been demonstrated to be effective in arresting caries lesions and, recently, clinical trials have assessed the effectiveness of SDF as... (Review)
Review
Silver diamine fluoride (SDF) has been demonstrated to be effective in arresting caries lesions and, recently, clinical trials have assessed the effectiveness of SDF as a medicament for indirect pulp therapy (IPT) in primary teeth. This review aims to summarize the literature related to the use of SDF and find out if SDF can be used as an effective material for IPT. A literature search was undertaken on electronic databases including PubMed, MEDLINE, ScienceDirect, and Google Scholar, which elicited 50 studies employing different materials in the IPT of primary molars; however, of them, only four clinical trials used SDF as indirect pulp capping (IPC) material. SDF has the potential to be a useful material for IPT in primary teeth. It is a handy choice for pediatric dentists due to its minimum invasiveness, ease of application, and ability to stop the progression of caries. However, more studies are needed to determine whether SDF can be used routinely for IPT and whether it can even replace the currently available materials, as well as to fully realize its potential and establish criteria for its ideal application in IPT procedures.
PubMed: 38903314
DOI: 10.7759/cureus.60780 -
Dental Materials : Official Publication... Jun 2024The purpose of this study was evaluating the performance of new Bis-EFMA based bulk-fill composites with common methacrylate based composites and commercial dental...
OBJECTIVES
The purpose of this study was evaluating the performance of new Bis-EFMA based bulk-fill composites with common methacrylate based composites and commercial dental composites.
METHODS
The Bis-EFMA monomer was synthesized and the novel Bis-EFMA based bulk-fill composites were prepared. The resin composite samples were co-cultured with human gingival epithelial cells and human dental pulp stem cells to test the biocompatibility. The edge adaptation was observed under a combination of stereoscope and scanning electron microscope. The internal hardness was measured using a Vickers microhardness tester after one-time filling of cavities prepared in extracted teeth. After friction and wear test on the surface of the resin composites, the surface morphology and volume wear of each group were measured by the optical profilometer. The color stability was measured by a colorimeter.
RESULTS
Direct contact with human gingival epithelial cells and human dental pulp stem cells did not cause significant changes in their growth density and morphology, indicating good biocompatibility of Bis-EFMA group (p > 0.05). The continuous margin proportion of the Bis-EFMA group was as good as commercial bulk-fill composites (p > 0.05). The sectional microhardness results showed that the Bis-EFMA group had the highest microhardness. After the friction and wear test, the volume wear of the Bis-EFMA group was minimal, indicating its good wear resistance and mechanical strength. Color changes in all resin groups after 28 days of immersion were within the clinically acceptable range.
SIGNIFICANCE
The addition of Bis-EFMA demonstrated excellent biocompatibility, edge adaptation and color stability comparable to commonly used clinical bulk-fill composites, along with preferable mechanical strength, friction and wear resistance. Bis-EFMA based bulk-fill composites have the potential to be employed as a bulk filling material in commercial dental composite applications.
PubMed: 38902144
DOI: 10.1016/j.dental.2024.06.025 -
Gene Jun 2024The aim of the present work was to find an efficient method for safe and reliable expansion of human dental pulp cells (hDPCs) in vitro. Here, we examined the effect of...
AIM
The aim of the present work was to find an efficient method for safe and reliable expansion of human dental pulp cells (hDPCs) in vitro. Here, we examined the effect of a novel recombinant E8 fragment of Laminin-511 (iMatrix-511) in hDPCs regarding viability and cell spreading. Further, we investigated the underlying mechanisms governing its effects in hDPCs using RNA sequencing (RNA-seq).
METHODOLOGY
hDPCs were obtained from caries-free maxilla third molars (n = 3). CCK-8 assay was conducted to measure the viability of cells cultured on iMatrix-511 and two other ECM proteins. Cell morphology was observed by phase contrast microscope. RNA-seq of hDPCs cultured on iMatrix-511 or noncoated control was performed on Illumina Novaseq 6000 platform.
RESULTS
iMatrix-511 (0.5 μg/cm) enhanced the viability of hDPCs to an extent better than COL-1 and gelatin. Short term culture of hDPCs on iMatrix-511 resulted in 233 differentially expressed genes (DEGs). The top 12 most upregulated genes were XIAP, AL354740, MRFAP1, AC012321, KCND3, TMEM120B, AC009812, GET1-SH3BGR, CNTN3, AC090409, GEN1 and PIK3IP1, whereas the top 12 most downregulated genes were SFN, KRT17, RAB4B-EGLN2, CSTA, KCTD11, ATP6V1G2-DDX39B, AC010323, SBSN, LYPD3, FOSB, AC022400 and CHI3L1. qPCR validation confirmed the significant upregulation of GEN1, KCND3, PIK3IP1 and MRFAP1. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed, with genes enriched in various extracellular matrix interaction, estrogen and fat metabolism-related functions and pathways.
CONCLUSIONS
iMatrix-511 facilitated spreading and proliferation of hDPCs. It enhances expression of anti-apoptotic genes, while inhibits expression of epidermis development-related genes.
PubMed: 38901533
DOI: 10.1016/j.gene.2024.148709 -
Compendium of Continuing Education in... May 2024The objective of this case study is to report on the diagnosis and treatment of medication-related osteonecrosis of the jaw (MRONJ), which was originally misdiagnosed...
The objective of this case study is to report on the diagnosis and treatment of medication-related osteonecrosis of the jaw (MRONJ), which was originally misdiagnosed and mistreated as endodontic disease. A patient was referred for worsening odontalgia despite root canal therapy on tooth No. 19 and a course of oral antibiotics. Examination demonstrated slight buccal swelling and tenderness in the left masseter and a 7-mm diameter area of exposed bone on the mandibular left lingual torus. Further history-taking revealed prior bisphosphonate therapy for metastatic breast cancer. MRONJ was identified as the likely diagnosis, and the patient was appropriately referred to oral and maxillofacial surgery where the diagnosis was confirmed and surgical debridement performed. The case study demonstrates how the symptomatology and presentation of MRONJ can resemble endodontic disease and that timely and appropriate treatment requires eliciting an in-depth medical history, reaching a complete pulpal and periapical diagnosis, and remaining attentive to the presence of exposed bone on examination.
Topics: Humans; Female; Bisphosphonate-Associated Osteonecrosis of the Jaw; Periapical Abscess; Diagnostic Errors; Diagnosis, Differential; Breast Neoplasms; Middle Aged
PubMed: 38900463
DOI: No ID Found -
Compendium of Continuing Education in... Jun 2024According to the American Dental Association Principles of Ethics and Code of Professional Conduct, dental professionals hold a special position of trust and privilege...
According to the American Dental Association Principles of Ethics and Code of Professional Conduct, dental professionals hold a special position of trust and privilege within society, and thus are bound to adhere to the highest standards of conduct. This code of ethics defines key tenets, including veracity, patient autonomy, beneficence, nonmaleficence, and justice. Maintaining these ethical principles goes beyond the competent delivery of operative care and requires up-to-date, evidence-based knowledge and practices on the part of clinicians.1 With pain management being a key component of endodontics practice, clinicians must maintain their knowledge on the most effective evidence-based pain management strategies to ethically care for their patients.
Topics: Humans; Evidence-Based Dentistry; Pain Management; Ethics, Dental
PubMed: 38900449
DOI: No ID Found