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Journal of Oral Biosciences Jun 2024This study aimed to investigate the regulatory mechanisms governing dental mesenchymal cell commitment during tooth development, focusing on odontoblast differentiation...
Exploring the Role of DNMT1 in Dental Papilla Cell Fate Specification during Mouse Tooth Germ Development through Integrated Single-Cell Transcriptomics and Bulk RNA Sequencing.
OBJECTIVES
This study aimed to investigate the regulatory mechanisms governing dental mesenchymal cell commitment during tooth development, focusing on odontoblast differentiation and the role of epigenetic regulation in this process.
METHODS
We performed single-cell RNA sequencing (scRNA-seq) of dental cells from embryonic day 14.5 (E14.5) mice to understand the heterogeneity of developing tooth germ cells. Computational analyses including gene regulatory network (GRN) assessment were conducted. We validated our findings using immunohistochemistry (IHC) and in vitro loss-of-function analyses using the DNA methyltransferase 1 (DNMT1) inhibitor Gsk-3484862 in primary dental mesenchymal cells (DMCs) isolated from E14.5 mouse tooth germs. Bulk RNA-seq of Gsk-3484862-treated DMCs was performed to identify potential downstream targets of DNMT1.
RESULTS
scRNA-seq analysis revealed diverse cell populations within the tooth germs, including epithelial, mesenchymal, immune, and muscle cells. Using single-cell regulatory network inference and clustering (SCENIC), we identified Dnmt1 as a key regulator of early odontoblast development. IHC analysis showed the ubiquitous expression of DNMT1 in the dental papilla and epithelium. Bulk RNA-seq of cultured DMCs showed that Gsk-3484862 treatment upregulated odontoblast-related genes, whereas genes associated with cell division and the cell cycle were downregulated. Integrated analysis of bulk RNA-seq data with scRNA-seq SCENIC profiles was used to identify the potential Dnmt1 target genes.
CONCLUSIONS
Dnmt1 may negatively affect odontoblast commitment and differentiation during tooth development. These findings contribute to a better understanding of the molecular mechanisms underlying tooth development and future development of hard-tissue regenerative therapies.
PubMed: 38942194
DOI: 10.1016/j.job.2024.06.010 -
Clinical Oral Investigations Jun 2024To investigate the four-year clinical outcome and marginal bone loss around narrow-diameter implants in patients with uncontrolled diabetes mellitus type 2 (T2DM) and...
OBJECTIVES
To investigate the four-year clinical outcome and marginal bone loss around narrow-diameter implants in patients with uncontrolled diabetes mellitus type 2 (T2DM) and normo-glycemic individuals.
MATERIALS AND METHODS
In 11 T2DM patients with a concentration of glycated hemoglobin (HbA1C) > 6.5% (test group) and 15 normoglycemic patients (HbA1C < 6.0%; control group), one narrow-diameter tissue level implant, placed in the posterior maxilla or mandible, was investigated. The clinical parameters probing depth (PD), bleeding on probing (BOP), attachment loss (CAL), recession, and papilla bleeding index (PBI) were assessed manually after 24 and 48 months of function. The paired digital periapical radiographs were analyzed regarding the change in marginal bone level (MBL) from baseline to 48 months post-op. The technical complications were recorded.
RESULTS
In the T2DM group, 11 patients were available for follow-ups. The overall implant survival rate after 48 months was 100%. The differences in means for the clinical parameters and the MBL between the T2DM and normo-glycemic patients for the observation period were statistically non-significant. No technical complications were recorded.
CONCLUSIONS
The study demonstrated an encouraging clinical outcome with ND implants in patients with uncontrolled T2DM compared to non-diabetics after 48 months' post loading.
CLINICAL RELEVANCE
Patients with HbA1C > 6.5% may benefit from the treatment with narrow-diameter implants by avoiding complex surgical interventions with augmentation procedures. REGISTRATION NUMBER (CLINICALTRIALS.GOV): NCT04630691.
Topics: Humans; Male; Female; Middle Aged; Case-Control Studies; Diabetes Mellitus, Type 2; Treatment Outcome; Dental Prosthesis Design; Dental Implants; Glycated Hemoglobin; Aged; Dental Implantation, Endosseous; Alveolar Bone Loss; Periodontal Index; Adult; Hyperglycemia
PubMed: 38907052
DOI: 10.1007/s00784-024-05786-0 -
Tissue Engineering and Regenerative... Jun 2024Stem cell-based transplantation therapy holds promise for peripheral nerve injury treatment, but adult availability is limited. A cell culture protocol utilizing a...
BACKGROUND
Stem cell-based transplantation therapy holds promise for peripheral nerve injury treatment, but adult availability is limited. A cell culture protocol utilizing a small-molecule cocktail effectively reprogrammed stem cells from apical papilla (SCAPs) into neural progenitor cells, subsequently differentiating into neuron-like cells. This study aims to evaluate neural-induced SCAPs, with and without small-molecule cocktail, for sciatic nerve repair potential.
METHODS
A scaffold-free cell sheet technique was used to construct a three-dimensional cell sheet. Subsequently, this cell sheet was carefully rolled into a tube and seamlessly inserted into a collagen conduit, which was then transplanted into a 5 mm sciatic nerve injury rat model. Functional sciatic nerve regeneration was evaluated via toe spread test, walking track analysis and gastrocnemius muscle weight. Additionally, degree of sciatic nerve regeneration was determined based on total amount of myelinated fibers.
RESULTS
Small-molecule cocktail induced SCAPs enhanced motor function recovery, evident in improved sciatic function index and gastrocnemius muscle retention. We also observed better host myelinated fiber retention than undifferentiated SCAPs or neural-induced SCAPs without small-molecule cocktail. However, clusters of neuron-like cell bodies (surrounded by sparse myelinated fibers) were found in all cell sheet-implanted groups in the implantation region. This suggests that while the implanted cells likely survived transplantation, integration was poor and would likely hinder long-term recovery by occupying the space needed for host nerve fibers to project through.
CONCLUSION
Neural-induced SCAPs with small-molecule cocktail demonstrated promising benefits for nerve repair; further research is needed to improve its integration and optimize its potential for long-term recovery.
PubMed: 38904732
DOI: 10.1007/s13770-024-00648-y -
Journal of Applied Oral Science :... 2024To explore the feasibility of injectable platelet-rich fibrin (i-PRF) in regenerative endodontics by comparing the effect of i-PRF and platelet-rich fibrin (PRF) on the... (Comparative Study)
Comparative Study
OBJECTIVE
To explore the feasibility of injectable platelet-rich fibrin (i-PRF) in regenerative endodontics by comparing the effect of i-PRF and platelet-rich fibrin (PRF) on the biological behavior and angiogenesis of human stem cells from the apical papilla (SCAPs).
METHODOLOGY
i-PRF and PRF were obtained from venous blood by two different centrifugation methods, followed by hematoxylin-eosin (HE) staining and scanning electron microscopy (SEM). Enzyme-linked immunosorbent assay (ELISA) was conducted to quantify the growth factors. SCAPs were cultured with different concentrations of i-PRF extract (i-PRFe) and PRF extract (PRFe), and the optimal concentrations were selected using the Cell Counting Kit-8 (CCK-8) assay. The cell proliferation and migration potentials of SCAPs were then observed using the CCK-8 and Transwell assays. Mineralization ability was detected by alizarin red staining (ARS), and angiogenesis ability was detected by tube formation assay. Real-time quantitative polymerase chain reaction (RT-qPCR) was performed to evaluate the expression of genes related to mineralization and angiogenesis. The data were subjected to statistical analysis.
RESULTS
i-PRF and PRF showed a similar three-dimensional fibrin structure, while i-PRF released a higher concentration of growth factors than PRF ( P <.05). 1/4× i-PRFe and 1/4× PRFe were selected as the optimal concentrations. The cell proliferation rate of the i-PRFe group was higher than that of the PRFe group ( P <.05), while no statistical difference was observed between them in terms of cell mitigation ( P >.05). More importantly, our results showed that i-PRFe had a stronger effect on SCAPs than PRFe in facilitating mineralization and angiogenesis, with the consistent result of RT-qPCR ( P <.05).
CONCLUSION
This study revealed that i-PRF released a higher concentration of growth factors and was superior to PRF in promoting proliferation, mineralization and angiogenesis of SCAPs, which indicates that i-PRF could be a promising biological scaffold for application in pulp regeneration.
Topics: Platelet-Rich Fibrin; Humans; Cell Proliferation; Microscopy, Electron, Scanning; Enzyme-Linked Immunosorbent Assay; Neovascularization, Physiologic; Regenerative Endodontics; Cells, Cultured; Real-Time Polymerase Chain Reaction; Intercellular Signaling Peptides and Proteins; Reproducibility of Results; Cell Movement; Stem Cells; Time Factors; Feasibility Studies; Analysis of Variance; Dental Papilla; Reference Values
PubMed: 38896639
DOI: 10.1590/1678-7757-2023-0449 -
International Endodontic Journal Jun 2024The dental pulp's environment is essential for the regulation of mesenchymal stem cells' homeostasis and thus, it is of great importance to evaluate the materials used...
Chitosan-based endodontic irrigation solutions and TGF-β1 treatment: Creating the most favourable environment for the survival and proliferation of stem cells of the apical papilla in vitro.
BACKGROUND
The dental pulp's environment is essential for the regulation of mesenchymal stem cells' homeostasis and thus, it is of great importance to evaluate the materials used in regenerative procedures.
AIM
To assess in vitro (i) the effect of chitosan nanoparticles, 0.2% chitosan irrigation solution, Dual Rinse®, 17% EDTA, 10% citric acid and 2.5% NaOCl on DSCS viability; (ii) the effect of different concentrations of TGF-β1 on DCSC proliferation; and (iii) whether treatment with TGF-β1 following exposure to the different irrigation solutions could compensate for their negative effects.
METHODOLOGY
(i) DSCS were treated with three dilutions (1:10, 1:100 and 1:1000) of the six irrigation solutions prepared in DMEM for 10 and 60 min to assess the effect on viability. (ii) The effect of different concentrations (0, 1, 5 and 10 ng/mL) of TGF-β1 on DCSC proliferation was assessed at 1, 3 and 7 days. (iii) The proliferative effect of TGF-β1 following 10-min exposure to 1:10 dilution of each irrigation solution was also tested. We used MTT assay to assess viability and proliferation. We performed statistical analysis using Prism software.
RESULTS
(i) The different endodontic irrigation solutions tested showed a significant effect on cell viability (p ≤ .0001). Significant interactions between the endodontic irrigation solutions and their dilutions were also found for all parameters (p ≤ .0001). Chitosan nanoparticles and 0.2% chitosan irrigation solution were the least cytotoxic to DSCS whilst 2.5% NaOCl was the most cytotoxic followed by 17% EDTA. (ii) TGF-β1 at concentrations of 1 and 5 ng/mL resulted in significantly higher proliferation compared to the control group. (iii) Exposure to 17% EDTA or 2.5% NaOCl for 10 min was sufficient to make DSCS cells refractory to the proliferative effects of TGF-β1. DSCS groups treated with TGF-β1 following exposure to chitosan nanoparticles, 0.2% chitosan irrigation solution, Dual Rinse® and 10% CA demonstrated significantly higher proliferation compared to non-TGF-β1-treated groups (p ≤ .0001, p ≤ .0001, p ≤ .0001 and p = .01 respectively).
CONCLUSIONS
The current study offers data that can be implemented to improve the outcome of regenerative endodontic procedures by using less toxic irrigation solutions and adding TGF-β1 to the treatment protocol.
PubMed: 38888363
DOI: 10.1111/iej.14112 -
Clinical Advances in Periodontics Jun 2024The gingival biotype (GB) influences treatment planning and clinical outcomes in several dental specialties. This study aimed to investigate the associations between the...
BACKGROUND
The gingival biotype (GB) influences treatment planning and clinical outcomes in several dental specialties. This study aimed to investigate the associations between the GB and various clinical crown and periodontal parameters, such as probing depth (PD), papillary height (PH), keratinized tissue width (KTW), crown width/crown length ratio (CW/CL), and gingival thickness (GT). The secondary objective was to evaluate the optimal cutoff values for all parameters to determine the GB in both the maxillary and mandibular anterior teeth.
METHODS
This cross-sectional study included 50 healthy individuals (26 men and 24 women) aged between 20 and 35 years. The GB was determined as a binary variable based on the transparency of a periodontal probe through the buccal gingival margin (TRAN). The clinical crown and periodontal parameters, such as PH, PD, KTW, GT (free gingival thickness [FGT] and attached gingival thickness [AGT]), and the CW/CL ratio were measured. The associations between different variables were evaluated by the chi-square test. Correlations between various clinical parameters and GB were assessed using point-biserial correlation analyses. Receiver operating characteristic (ROC) analysis and the Youden index were used to calculate the optimal cutoff values for the PH, PD, KTW, FGT, AGT, and CW/CL ratio to discriminate GB. The statistical significance level was set at p < 0.05.
RESULTS
The mean age of the males was 28.23 ± 2.81 years, while that of the females was 27.08 ± 2.85 years. Thick GB was present in 56% of individuals, and thin GB was present in 44% of individuals. Compared with females, males had a predilection for thick GB compared with females. According to the ROC analysis, the cutoff values to discriminate GB for mandibular anterior teeth were 3.4 mm for PH, 1.96 mm for PD, 4.21 mm for KTW, 0.98 mm for FGT, 0.43 mm for AGT, and 0.91 for the CW/CL ratio. Similarly, the cutoff values for discriminating the GB for maxillary anterior teeth were 4.02 mm for PH, 1.92 mm for PD, 3.89 mm for KTW, 1.02 mm for FGT, 0.42 mm for AGT, and 0.83 for the CW/CL ratio. PH, PD, and FGT showed strong positive correlations with GB, whereas KTW, AGT, and the CW/CL ratio showed weak positive correlation with GB.
CONCLUSION
Within the limitations of the present study, a significant association between all clinical crown and periodontal parameters with the GB has been confirmed. FGT for mandibular anterior teeth and PH for the mandibular anterior teeth have emerged as the most reliable measurements to differentiate between thick and thin GB based on ROC analysis.
KEY POINTS
All the clinical parameters such as papillary height, probing depth, width of keratinized gingiva, gingival thickness, and crown width/height ratio were significantly associated with gingival biotype. Free gingival thickness for mandibular anterior teeth and papillary height for the maxillary anterior teeth have emerged as the most reliable measurement to differentiate between thick and thin gingival biotypes.
PubMed: 38884937
DOI: 10.1002/cap.10302 -
Scientific Reports Jun 2024Notum is a direct target of Wnt/β-catenin signaling and plays a crucial role as a Wnt inhibitor within a negative feedback loop. In the tooth, Notum is known to be...
Notum is a direct target of Wnt/β-catenin signaling and plays a crucial role as a Wnt inhibitor within a negative feedback loop. In the tooth, Notum is known to be expressed in odontoblasts, and severe dentin defects and irregular tooth roots have been reported in Notum-deficient mice. However, the precise expression pattern of Notum in early tooth development, and the role of Notum in crown and root patterns remain elusive. In the present study, we identified a novel Notum expression in primary enamel knot (EK), secondary EKs, and dental papilla during tooth development. Notum-deficient mice exhibited enlarged secondary EKs, resulting in broader cusp tips, altered cusp patterns, and reduced concavity in crown outline. These alterations in crown outline led to a reduction in cervical tongue length, thereby inducing root fusion in Notum-deficient mice. Overall, these results suggest that the secondary EK size, regulated by the Wnt/Notum negative feedback loop, has a significant impact on the patterns of crown and root during tooth morphogenesis.
Topics: Animals; Mice; Gene Expression Regulation, Developmental; Mice, Knockout; Molar; Odontogenesis; Receptors, G-Protein-Coupled; Tooth Crown; Tooth Root; Wnt Signaling Pathway
PubMed: 38871845
DOI: 10.1038/s41598-024-64340-w -
Acta Odontologica Scandinavica Jun 2024Non-surgical therapeutics to reconstruct lost interdental papilla are evolving; these include hyaluronic acid injection. The aim of this systematic review is to evaluate...
OBJECTIVE
Non-surgical therapeutics to reconstruct lost interdental papilla are evolving; these include hyaluronic acid injection. The aim of this systematic review is to evaluate the efficacy, safety, and long-term outcomes of hyaluronic acid injection in the treatment of black triangles and reconstruction of lost interdental papilla in anterior teeth.
MATERIALS AND METHODS
The protocol was registered in PROSPERO (CRD42023446875) and in accordance with the Cochrane Handbook of Systematic Reviews of Interventions and the Preferred Reporting Items for Systematic Reviews and Meta-Analysis 'PRISMA'. The search involved four databases, PubMed/MEDLINE, The Cochrane Library, Google Scholar, and ProQuest for ''grey literature' with additional manual search for studies published up to May 2024. Human clinical studies of a prospective nature (randomised clinical trials and prospective cohort studies) were included. Exclusion criteria were case reports, case series, review articles, letter to editor, personal opinion, and animal studies. Furthermore, studies which utilised hyaluronic acid injection in conjunction with other therapeutic material, tissue graft, or any surgical procedure were also excluded. The data were extracted independently by the two authors and incorporated after consensus. The risk of bias was assessed using the RoB2: the revised Cochrane risk of bias tool for randomised clinical trials and the Newcastle Ottawa scale for prospective cohort studies.
RESULTS
24 studies, 15 prospective clinical studies and nine randomised clinical trials, were included with a total of 898 interdental papillae injected with hyaluronic acid. The studies showed promising outcomes in the reconstruction of lost interdental papilla with minimal adverse reactions. Risk of bias assessment among prospective clinical studies revealed 13 good quality studies with only two poor studies while the randomised clinical trials consisted of three with low, one with some concern, and five studies with high risk of bias. However, due to the high heterogeneity, a meta-analysis was not feasible. Conclusion: Hyaluronic acid injection is an effective minimally invasive approach in treating black triangles and reconstructing lost interdental papilla in the anterior teeth. Further long-term well-designed randomised clinical trials employing standardised procedures are essential to validate this treatment and provide better quality of evidence.
Topics: Hyaluronic Acid; Humans; Dental Papilla
PubMed: 38864684
DOI: 10.2340/aos.v83.40864 -
Clinical Advances in Periodontics Jun 2024As the need for using dental implants to replace single missing teeth grows, so does the demand for greater esthetic results. However, achieving complete interproximal...
BACKGROUND
As the need for using dental implants to replace single missing teeth grows, so does the demand for greater esthetic results. However, achieving complete interproximal papillae fill in single-tooth implant restorations remains a challenge. The distally anchored connective tissue platform is a novel soft tissue augmentation technique that consists of harvesting an autogenous connective tissue graft from the palate, folding it, and positioning it at the level of the distal occlusal and buccal surfaces with the help of a distal sling suture to the adjacent distal tooth.
METHODS
This case report describes how a maxillary central incisor with compromised hard and soft tissues were replaced using a comprehensive treatment plan.
RESULTS
The clinical outcomes showed stable mucosal margin levels and complete papillae fill. The patient expressed satisfaction with the achieved results.
CONCLUSIONS
The distally anchored connective tissue graft platform performed at the time of implant placement emerges as a viable and effective soft tissue augmentation technique that yields highly esthetic results.
KEY POINTS
Why is this case new information? To the best of our knowledge, this is the first case report in the literature using the distally anchored connective tissue platform. What are the keys to successful management of this case? Adequate diagnosis and decision-making, resulting in a treatment plan focused on reconstructing both soft and hard tissues in a single-tooth implant within the esthetic area, yield favorable clinical, radiological, and patient-reported outcomes. What are the primary limitations to success in this case? The primary limitation of this study is its reliance on a single case report.
PubMed: 38853678
DOI: 10.1002/cap.10299 -
Molecular Biology Reports Jun 2024Circular RNA (circRNA) is a key player in regulating the multidirectional differentiation of stem cells. Previous research by our group found that the blue...
BACKGROUND
Circular RNA (circRNA) is a key player in regulating the multidirectional differentiation of stem cells. Previous research by our group found that the blue light-emitting diode (LED) had a promoting effect on the osteogenic/odontogenic differentiation of human stem cells from apical papilla (SCAPs). This research aimed to investigate the differential expression of circRNAs during the osteogenic/odontogenic differentiation of SCAPs regulated by blue LED.
MATERIALS AND METHODS
SCAPs were divided into the irradiation group (4 J/cm) and the control group (0 J/cm), and cultivated in an osteogenic/odontogenic environment. The differentially expressed circRNAs during osteogenic/odontogenic differentiation of SCAPs promoted by blue LED were detected by high-throughput sequencing, and preliminarily verified by qRT-PCR. Functional prediction of these circRNAs was performed using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) and the circRNA-miRNA-mRNA networks were also constructed.
RESULTS
It showed 301 circRNAs were differentially expressed. GO and KEGG analyses suggested that these circRNAs were associated with some signaling pathways related to osteogenic/odontogenic differentiation. And the circRNA-miRNA-mRNA networks were also successfully constructed.
CONCLUSION
CircRNAs were involved in the osteogenic/odontogenic differentiation of SCAPs promoted by blue LED. In this biological process, circRNA-miRNA-mRNA networks served an important purpose, and circRNAs regulated this process through certain signaling pathways.
Topics: RNA, Circular; Humans; Osteogenesis; Cell Differentiation; Stem Cells; Odontogenesis; Dental Papilla; Light; MicroRNAs; Gene Ontology; Cells, Cultured; Gene Expression Profiling; RNA, Messenger; Gene Regulatory Networks; High-Throughput Nucleotide Sequencing; Gene Expression Regulation; Blue Light
PubMed: 38824241
DOI: 10.1007/s11033-024-09621-3