Comparison of in vitro properties of periodontal ligament stem cells derived from permanent and deciduous teeth

An Assessment of Periodontal Status and Oral Hygiene in Patients with Hypertension in the South-West Region of Romania

Background: This cross-sectional analytical study evaluates oral hygiene and periodontal status in patients with hypertension, given the established link between cardiovascular diseases and poor periodontal health. Methods: A total of 24 hypertensive patients (15 male; 9 female) and 30 healthy controls (19 male; 11 female) from Craiova, Romania, were assessed using Periodontal Probing Depth (PPD), the Plaque Index (PLQ), and the Bleeding on Probing Index (BPI). Results: The mean age was 62.2 years in the hypertensive group and 47.4 years in the control group. Oral hygiene was poorer in hypertensive patients (PLQ: 73% vs. 24.1% in controls), with higher PPD (5.2 mm vs. 3.7 mm) and BPI (82% vs. 23%). Among patients with dental implants, PLQ was 24% in hypertensive individuals vs. 15.6% in controls, PPD was 4.4 mm vs. 2.9 mm, and BPI was 44% vs. 15.5%. Conclusions: These findings indicate a higher risk of periodontal disease in hypertensive patients, though dental implants may decrease some adverse effects by improving oral hygiene and periodontal health in this population. In conclusion, our study highlights that patients with high blood pressure have a less favorable periodontal status compared to healthy controls.

Impact of various endodontic sealers on HPDLF Cell viability and apoptosis

This study aimed to investigate the cytotoxicity and apoptotic activity of different endodontic sealers: Sealapex, Apexit Plus, AH Plus, MTA-Fillapex and TotalFill BC Sealer in the culture of human periodontal ligament fibroblast (HPDLF) cells. The sealers were mixed, set for 24 h, and then covered with culture medium to obtain extracts, which were diluted to 1:0, 1:1, 1:2, 1:4, and 1:8. Simultaneously, HPDLF cells (1 × 104) were seeded in 96-well plates and incubated for 24 h at 37 °C 5% CO2 conditions. The cells were then exposed to 100 µL of diluted extract medium. Cytotoxicity was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay to check cell viability, while apoptosis was assessed by TUNEL assay. Statistical analyses were performed using Kruskal-Wallis and Dunn post hoc tests with Mann Whitney U. In MTT and TUNEL assay cells were treated with sealers both 24 and 72 h. All materials showed higher toxicity at 72 h compared to 24 h. AH Plus exhibited the highest cytotoxicity, followed by MTA-Fillapex, Apexit Plus, Sealapex, while TotalFill BC Sealer had the lowest cytotoxicity. Consuquently, it was considered that TotalFill BC Sealer had the lowest cytotoxic potency when compared to other sealers, so it can be considered biocompatible.

Emerging role of mesenchymal stem cell-derived extracellular vesicles in periodontal regeneration

Periodontitis is a prevalent oral ailment that harms both hard and soft tissues of the periodontium, leading to loosening and eventual removal of the teeth. Current clinical treatments have limitations in achieving complete periodontal tissue regeneration. Mesenchymal stem cells (MSCs) have garnered attention due to their unique characteristics and potential as a promising new therapy for periodontitis. Research suggests that the role of MSCs in regenerative medicine primarily occurs through the paracrine pathway, involving the emission of particles encased by lipids called extracellular vesicles (EVs) abundant in bioactive compounds. These EVs play a vital function in controlling the activities of periodontal tissues and immune system cells, and by influencing the immediate surrounding, thus fostering the healing of periodontal damage and renewal of tissues. EVs obtained from MSCs (MSC-EVs), in the form of a cell-free treatment, offer advantages in terms of stability, reduced immune rejection, and ethical considerations, elevating their potential as a hopeful choice for broad clinical applications. This concise overview highlights the mechanisms of MSC-EVs and the possibilities they hold in clinical application for periodontal regeneration.

Comparison of Periodontal Ligament Stem Cells with Mesenchymal Stem Cells from Other Sources: A Scoping Systematic Review of In vitro and In vivo Studies

OBJECTIVE

The application of stem cells in regenerative medicine depends on their biological properties. This scoping review aimed to compare the features of periodontal ligament stem cells (PDLSSCs) with stem cells derived from other sources.

DESIGN

An electronic search in PubMed/Medline, Embase, Scopus, Google Scholar and Science Direct was conducted to identify in vitro and in vivo studies limited to English language.

RESULTS

Overall, 65 articles were included. Most comparisons were made between bone marrow stem cells (BMSCs) and PDLSCs. BMSCs were found to have lower proliferation and higher osteogenesis potential in vitro and in vivo than PDLSCs; on the contrary, dental follicle stem cells and umbilical cord mesenchymal stem cells (UCMSCs) had a higher proliferative ability and lower osteogenesis than PDLSCs. Moreover, UCMSCs exhibited a higher apoptotic rate, hTERT expression, and relative telomerase length. The immunomodulatory function of adipose-derived stem cells and BMSCs was comparable to PDLSCs. Gingival mesenchymal stem cells showed less sensitivity to long-term culture. Both pure and mixed gingival cells had lower osteogenic ability compared to PDLSCs. Comparison of dental pulp stem cells (DPSCs) with PDLSCs regarding proliferation rate, osteo/adipogenesis, and immunomodulatory properties was contradictory; however, in vivo bone formation of DPSCs seemed to be lower than PDLSCs.

CONCLUSION

In light of the performed comparative studies, PDLSCs showed comparable results to stem cells derived from other sources; however, further in vivo studies are needed to determine the actual pros and cons of stem cells in comparison to each other.

Periodontal ligament stem cell isolation protocol: A systematic review

Despite the plethora of literature regarding isolation and characterization of periodontal ligament stem cells (PDLSCs), due to the existence of controversies in the results, in this comprehensive review, we aimed to summarize and compare the effect of isolation methods on PDLSC properties, including clonogenicity, viability/proliferation, markers expression, cell morphology, differentiation, and regeneration. Moreover, the outcomes of included studies, considering various parameters such as teeth developmental stages, donor age, periodontal ligament health status, and part of the teeth root from which PDLSCs were derived, have been systematically discussed. It has been shown that from included studies PDLSCs can be isolated from teeth from any developmental stages, any health status condition, and any donor age. Also, a non-enzymatic digestion method, named as an explant or outgrowth technique, is a suitable protocol for of PDLSCs isolation.

Isolation, Characterization, and Differentiation of Stem Cells From Various Dental Sources: An In Vitro Study

Aim:

The aim of the current study was to isolate stem cells from various dental sources such as dental pulp, periodontal ligament (PDL), and apical papilla, and to characterize stem cells by staining for the presence/absence of specific surface markers and also to differentiate stem cells into osteogenic, chondrogenic, and adipogenic cell lineages by exposing them to specific growth factors under the ideal conditions.

Materials and Methods:

A total of 117 samples were included in the study, consisting of 30 pulp, 50 gingival, 35 PDL, and 2 apical papilla samples. The pulp was extirpated and transported to the Central Research Laboratory. Gingival connective tissue was collected from the participants undergoing any crown lengthening procedure or any gingivectomy procedure from the Department of Periodontology. A similar procedure was also followed for apical papilla and PDL. Isolation was done followed by the identification of the cells by immunocytochemistry using different markers. Once the identity of cells was confirmed, these cells were treated with different culture media to attain 70% to 100% confluency. Then the medium was replaced with a conditioning medium containing specific growth factors for differentiation into osteogenic, chondrogenic, and adipogenic cell lineages.

Result:

In our study, the number of samples collected and processed was 117. The isolation rate of stem cells from the above-collected samples was 70%. Statistical analysis—no statistical analysis was done as there was no variability expected.

Conclusion:

Our study showed that stem cells could be isolated, differentiated, and characterized from different dental sources.

Extracellular vesicles in bone and periodontal regeneration: current and potential therapeutic applications

Oral mesenchymal stem cells (MSCs) and their secretomes are considered important factors in the field of medical tissue engineering and cell free biotherapy due to their ease of access, differentiation potential, and successful therapeutic outcomes. Extracellular vesicles (EVs) and the conditioned medium (CM) from MSCs are gaining more attraction as an alternative to cell-based therapies due to the less ethical issues involved, and their easier acquisition, preservation, long term storage, sterilization, and packaging. Bone and periodontal regenerative ability of EVs and CM have been the focus of some recent studies. In this review, we looked through currently available literature regarding MSCs' EVs or conditioned medium and their general characteristics, function, and regenerative potentials. We will also review the novel applications in regenerating bone and periodontal defects.

Mesenchymal stem cell markers in periodontal tissues and periapical lesions

INTRODUCTION

Mesenchymal stem cells (MSCs) are characterized by the potential to differentiate into multiple cell lineages, high proliferation rates, and self-renewal capacity, in addition to the ability to maintain their undifferentiated state. These cells have been identified in physiological oral tissues such as pulp tissue, dental follicle, apical papilla and periodontal ligament, as well as in pathological situations such as chronic periapical lesions (CPLs). The criteria used for the identification of MSCs include the positive expression of specific surface antigens, with CD73, CD90, CD105, CD44, CD146, STRO-1, CD166, NANOG and OCT4 being the most specific for these cells.

AIM

The aim of this review was to explore the literature on markers able to identify MSCs as well as the presence of these cells in the healthy periodontal ligament and CPLs, highlighting their role in regenerative medicine and implications in the progression of these lesions.

METHODS

Narrative literature review searching the PubMed and Medline databases. Articles published in English between 1974 and 2020 were retrieved.

CONCLUSION

The included studies confirmed the presence of MSCs in the healthy periodontal ligament and in CPLs. Several surface markers are used for the characterization of these cells which, although not specific, are effective in cell recognition. Mesenchymal stem cells participate in tissue repair, exerting anti- inflammatory, immunosuppressive and proangiogenic effects, and are therefore involved in the progression and attenuation of CPLs or even in the persistence of these lesions.

Spatial Distributions, Characteristics, and Applications of Craniofacial Stem Cells

Stem cells play an irreplaceable role in the development, homeostasis, and regeneration of the craniofacial bone. Multiple populations of tissue-resident craniofacial skeletal stem cells have been identified in different stem cell niches, including the cranial periosteum, jawbone marrow, temporomandibular joint, cranial sutures, and periodontium. These cells exhibit self-renewal and multidirectional differentiation abilities. Here, we summarized the properties of craniofacial skeletal stem cells, based on their spatial distribution. Specifically, we focused on the in vivo genetic fate mapping of stem cells, by exploring specific stem cell markers and observing their lineage commitment in both the homeostatic and regenerative states. Finally, we discussed their application in regenerative medicine.