Periodontal bone defects, primarily caused by periodontitis, are highly prevalent in clinical settings and manifest as bone fenestration, dehiscence, or attachment loss, presenting a significant challenge to oral health. In regenerative medicine, harnessing developmental principles for tissue repair offers promising therapeutic potential. Of particular interest is the condensation of progenitor cells, an essential event in organogenesis that has inspired clinically effective cell aggregation approaches in dental regeneration. However, the precise cellular coordination mechanisms during condensation and regeneration remain elusive. Here, taking the tooth as a model organ, we employed single-cell RNA sequencing to dissect the cellular composition and heterogeneity of human dental follicle and dental papilla, revealing a distinct Platelet-derived growth factor receptor alpha (PDGFRA) mesenchymal stem/stromal cell (MSC) population with remarkable odontogenic potential. Interestingly, a reciprocal paracrine interaction between PDGFRA⁺ dental follicle stem cells (DFSCs) and CD31⁺ Endomucin⁺ endothelial cells (ECs) was mediated by Vascular endothelial growth factor A (VEGFA) and Platelet-derived growth factor subunit BB (PDGFBB). This crosstalk not only maintains the functionality of PDGFRA⁺ DFSCs but also drives specialized angiogenesis. In vivo periodontal bone regeneration experiments further reveal that communication between PDGFRA⁺ DFSC aggregates and recipient ECs is essential for effective angiogenic-osteogenic coupling and rapid tissue repair. Collectively, our results unravel the importance of MSC-EC crosstalk mediated by the VEGFA and PDGFBB-PDGFRA reciprocal signaling in orchestrating angiogenesis and osteogenesis. These findings not only establish a framework for deciphering and promoting periodontal bone regeneration in potential clinical applications but also offer insights for future therapeutic strategies in dental or broader regenerative medicine.
Receptor, Platelet-Derived Growth Factor alpha/metabolism* ; Humans ; Neovascularization, Physiologic/physiology* ; Dental Sac/cytology* ; Single-Cell Analysis ; Transcriptome ; Mesenchymal Stem Cells/metabolism* ; Bone Regeneration ; Animals ; Dental Papilla/cytology* ; Periodontium/physiology* ; Stem Cells/metabolism* ; Regeneration ; Angiogenesis

Periodontitis is a chronic infective disease characterized as the destruction of the supporting tissues of the teeth. Bone marrow mesenchymal stem cells, which are ideal adult stem cells for the regeneration of supporting tissues, may play important roles in restoring the structure and function of the periodontium and in promoting the treatment of periodontal disease. As a consequence, the characteristics, especially osteogenic differentiation mechanism, of these stem cells have been extensively investigated. The regulation of the physiological behavior of these stem cells is associated with BMAL1 gene. This gene is a potential treatment target for periodontal disease, although the specific mechanism remains inconclusive. This study aimed to describe the characteristics of BMAL1 gene and its ability to regulate the osteogenic differentiation of stem cells.
ARNTL Transcription Factors ; genetics ; Adult ; Adult Stem Cells ; Bone Marrow Cells ; physiology ; Cell Differentiation ; Hematopoietic Stem Cells ; Humans ; Mesenchymal Stromal Cells ; physiology ; Osteogenesis ; physiology ; Periodontal Ligament ; Periodontitis ; Periodontium ; Regeneration ; Tooth

OBJECTIVETo study the remodeling of the anterior alveolar bone with parodontium under physiology loading using finite element method (FEM) and theory of bone remodeling.

METHODSA FEM model of the maxillary central incisor with parodontium was established, and the change of bone density during the remodeling of alveolar bone was investigated under physiology loading (60 - 150 N) based on the theory of bone remodeling about strain energy density (SED). The finite element analysis software Abaqus user material subroutine (UMAT) were used.

RESULTSWith the increase of physiology loading, the pressure stress on the buccal cervical margin increased gradually while the density was decreased gradually. The cortical bone was lower than its initial density 1.74 g/cm(3), which was 1.74 - 1.63 g/cm(3). The density of cancellous bone was 0.90 - 0.77 g/cm(3), which was lower than its intial density 0.90 g/cm(3). The lingual cervical margin was under tensile stress which also increased with loading, the density had no significant change. When the achieve to 120 N, the density of cortical bone was 1.74 - 1.73 g/cm(3). No significant change was found in the cancellous bone.

CONCLUSIONSThe simulation of the perodontium remodeling is achieved and proved to be effective by the relevant research based on the method of the study. And the result will be helpful to form the basis of analysis bone remodeling process and predict the results in the clinical work.

Alveolar Process ; physiology ; Bone Density ; Bone Remodeling ; physiology ; Computer Simulation ; Dental Stress Analysis ; methods ; Finite Element Analysis ; Humans ; Incisor ; physiology ; Maxilla ; physiology ; Periodontium ; physiology ; Stress, Mechanical

Animals ; Biocompatible Materials ; pharmacology ; Bone Morphogenetic Proteins ; pharmacology ; Cell Movement ; Chemokine CXCL12 ; pharmacology ; Drug Delivery Systems ; Guided Tissue Regeneration, Periodontal ; methods ; Humans ; Periodontal Ligament ; cytology ; Periodontium ; cytology ; physiology ; Regeneration ; drug effects ; Stem Cells ; cytology

A 3D finite element model of bilateral distal-extension edentulous dentition, which includes mandible, incisors, canines and premolars, was established in the first place. Based on it, another model with extra-coronal attachments and dentures was also developed. Moreover, contact elements were applied to the regions between the denture and alveolar bone. The von Mises stress distributions of the abutments and their periodontal tissues, edentulous alveolar bone in the two models were compared. The results indicate that the stresses in the abutments and the alveolar sockets obviously increase at the buccal and lingual sides after reparation, and that the stresses on the edentulous alveolar bone also increase.
Dental Abutments ; Dental Stress Analysis ; Denture Design ; Denture Precision Attachment ; Finite Element Analysis ; Humans ; Models, Biological ; Periodontium ; physiology

BACKGROUNDGuided tissue regeneration procedures provide predictable reconstruction of periodontal tissues in the treatment of furcation involvements in animals and humans. This study was to compare long-term effectiveness of two different types of polylactic acid (PLA) membranes on periodontal regeneration in surgically created class II furcation defects in dogs.

METHODSFull thickness mucoperiosteal flap was raised on the buccal aspects of the experimental teeth and class II furcation defects having 5 mm vertical dimensions were created on mandibular premolar III and IV on each quadrant. The exposed root surfaces were thoroughly planed and PLA membranes were placed over the experimental defects on both sites. One site received liquid polymer membrane (LPM), and resorbable periodontal mesh (RPM) membranes were applied to the other site. The animals were sacrificed at 7 months after surgery and the specimens were processed for histological evaluation.

RESULTSThe average length of new attachment formed on the treated roots in both groups ranged from 3.02 mm to 4.5 mm. Complete bone filling was observed at the furcation sites. No statistically significant differences were found between two membranes in any of the parameters (P > 0.05).

CONCLUSIONThis study demonstrates favorable regenerative outcomes by the use of two different types of PLA membranes that could be used as alternatives for guided tissue regeneration (GTR).

Animals ; Dogs ; Furcation Defects ; surgery ; Guided Tissue Regeneration, Periodontal ; methods ; Lactic Acid ; analogs & derivatives ; therapeutic use ; Periodontium ; physiology ; Polymers ; therapeutic use ; Wound Healing ; physiology

OBJECTIVETo observe the results of surgical crown lengthening procedure and the factors which affected the success of the surgery.

METHODSCrown lengthening surgery was performed on 27 teeth. The distance between margin of tooth and bone crest (MT-B) was obtained greater than 4 mm during the surgeries on 10 teeth which were considered as satisfying group. The other 17 teeth were as temporized group with MT-B < or = 3 mm. The position of the tooth margin was evaluated before surgery, immediately after suturing, and at 4 - 6 weeks after surgery. The occlusal force and tooth mobility were measured immediately after restoration, at 3 and 6 months after surgery.

RESULTSMT-B was obtained > or = 4 mm and all margins and sites of the teeth were exposed in satisfying group (10/10). At least 1 site with MT-B < 3 mm in temporized group in which there still were 11 sites (16%) in 5 teeth (29%) with subgingival tooth margin at 4 - 6 weeks after surgery. There were more teeth showing increased mobility in temporized group (12/17) than in satisfying group (1/10) after surgery (P < 0.05). The occlusal force of the teeth after surgery and restoration in temporized group was significantly lower than that of their counterpart teeth (P < 0.01), but it was not the case in satisfying group (P > 0.05).

CONCLUSIONSIt is suggested that ideal exposure of tooth margin could be obtained if 4 mm from tooth margin to alveolar crest could be created during the crown lengthening surgery. The teeth both with 4 - 5 mm subgingival margin sites and factors limiting surgical performance are not the suitable indications for the surgical crown lengthening.

Alveolectomy ; Crown Lengthening ; methods ; Follow-Up Studies ; Gingiva ; anatomy & histology ; Humans ; Periodontium ; anatomy & histology ; physiology ; Prospective Studies ; Tooth Crown ; pathology

OBJECTIVETo study the expression of IL-6 in periodontal ligament fibroblasts (PLF) and osteoblasts in order to explain the molecular mechanism of the bite forte on periodontium remodeling.

METHODSA rat model of different bite forces was established to study the expression of IL-6 and IL-6 mRNA in the PLF and osteoblasts with immunohistochemical (IHC) and in situ hybridization (ISH) techniques.

RESULTSIn the group of disuse bite force, the expression of IL-6 and IL-6 mRNA in the PLF and osteoblasts enhanced apparently compared with that in the group of normal bite force. The gray level values enhanced respectively from 6.5886 +/- 1.6 to 38.8381 +/- 9.5 and from 11.8337 +/- 2.8 to 57.2623 +/- 13.6. The loosely arrangement of periodontal fibers and the resorption of alveolar bone were observed in histological study. In the group of compensation bite force, the same result was observed with IHC and ISH, the gray level values enhanced respectively from 6.3119 +/- 1.5 to 45.5456 +/- 11.1 and from 11.7714 +/- 2.8 to 81.9391 +/- 19.5, but the increase of periodontal fibers, the resorption and formation of alveolar bone were observed simultaneity in histological study.

CONCLUSIONSWith the change of bite force, the expression of IL-6 and IL-6 mRNA in PLF and osteoblasts presents a certain regulation. IL-6 may play important roles in the effect of bite force on periodontium remodeling.

Animals ; Bite Force ; Immunohistochemistry ; In Situ Hybridization ; Interleukin-6 ; analysis ; genetics ; Male ; Periodontium ; physiology ; RNA, Messenger ; analysis ; Rats ; Rats, Wistar ; Transcription, Genetic