-
Dental Clinics of North America Jan 2022The ultimate goal of periodontal therapy is homeostatic regeneration of lost attachment of alveolar bone and gingival connective tissue to the exposed root surfaces with... (Review)
Review
The ultimate goal of periodontal therapy is homeostatic regeneration of lost attachment of alveolar bone and gingival connective tissue to the exposed root surfaces with a fully functional and healthy periodontal ligament that is covered with a healthy epithelium. This goal needs a complete understanding of the biological mechanisms inherent to healing and inflammatory processes.
Topics: Connective Tissue; Gingiva; Humans; Periodontal Ligament; Tooth Root; Wound Healing
PubMed: 34794547
DOI: 10.1016/j.cden.2021.08.001 -
The Chinese Journal of Dental Research Jun 2022The ultimate goal of periodontal treatments is the regeneration of all lost periodontal tissues including bone, cementum and the periodontal ligament (PDL). Until now,... (Review)
Review
The ultimate goal of periodontal treatments is the regeneration of all lost periodontal tissues including bone, cementum and the periodontal ligament (PDL). Until now, the clinical methods for periodontal regeneration have been associated with significant failure or incomplete success. Various studies have reported the promising effects of growth factors/cytokines on periodontal regeneration. Growth factors/cytokines include proteins or steroid hormones that bind to cellular receptors, known as signalling molecules, and that trigger cellular responses that eventually stimulate cell proliferation and differentiation. The present review aims to provide an overview of the main growth factors that play an important role in and have been used in the regeneration of periodontal components.
Topics: Cementogenesis; Cytokines; Dental Cementum; Periodontal Ligament; Periodontium
PubMed: 35686588
DOI: 10.3290/j.cjdr.b3086335 -
Journal of Dental Research Nov 2023Physiologically, teeth and periodontal tissues are exposed to occlusal forces throughout their lifetime. Following occlusal unloading, unbalanced bone remodeling...
Physiologically, teeth and periodontal tissues are exposed to occlusal forces throughout their lifetime. Following occlusal unloading, unbalanced bone remodeling manifests as a net alveolar bone (AB) loss. This phenomenon is termed (ABDO), the underlying mechanism of which remains unclear. Type H vessels, a novel capillary subtype tightly coupled with osteogenesis, reportedly have a role in skeletal remodeling; however, their role in ABDO is not well studied. In the present study, we aimed to explore the pathogenesis of and therapies for ABDO. The study revealed that type H endothelium highly positive for CD31 and endomucin was identified in the periodontal ligament (PDL) but rarely in the AB of the mice. In hypofunctional PDL, the density of type H vasculature and coupled osterix (OSX) osteoprogenitors declined significantly. In addition, the angiogenic factor Slit guidance ligand 3 (SLIT3) was downregulated in the disused PDL, and periodontal injection of the recombinant SLIT3 protein partially ameliorated type H vessel dysfunction and AB loss in ABDO mice. With regard to the molecular mechanism, a mechanosensory signaling circuit, PIEZO1/Ca/HIF-1α/SLIT3, was validated by applying cyclic compression to 3-dimensional-cultured PDL cells using the Flexcell FX-5000 compression system. In summary, PDL plays a pivotal role in mechanotransduction by translating physical forces into the intracellular signaling axis PIEZO1/Ca/HIF-1α/SLIT3, which promotes type H angiogenesis and OSX cell-related osteogenensis, thereby contributing to AB homeostasis. Our findings advance the understanding of PDL in AB disorders. Further therapies targeting SLIT3 may provide new insights into preventing bone loss in ABDO.
Topics: Mice; Animals; Bite Force; Mechanotransduction, Cellular; Tooth; Periodontal Ligament; Alveolar Bone Loss; Homeostasis
PubMed: 37786932
DOI: 10.1177/00220345231191745 -
International Journal of Molecular... Nov 2022The tooth-periodontium complex and its nerves have active reciprocal regulation during development and homeostasis. These effects are predominantly mediated by a range... (Review)
Review
The tooth-periodontium complex and its nerves have active reciprocal regulation during development and homeostasis. These effects are predominantly mediated by a range of molecules secreted from either the nervous system or the tooth-periodontium complex. Different strategies mimicking tooth development or physiological reparation have been applied to tooth regeneration studies, where the application of these nerve- or tooth-derived molecules has been proven effective. However, to date, basic studies in this field leave many vacancies to be filled. This literature review summarizes the recent advances in the basic studies on neural responses and regulation during tooth-periodontium development and homeostasis and points out some research gaps to instruct future studies. Deepening our understanding of the underlying mechanisms of tooth development and diseases will provide more clues for tooth regeneration.
Topics: Odontogenesis; Periodontal Ligament; Tooth; Periodontium; Homeostasis
PubMed: 36430624
DOI: 10.3390/ijms232214150 -
Journal of the Mechanical Behavior of... Oct 2023The periodontium is a biological structure that supports the tooth in the jaw and behave as a developmental, biological, and functional unit. Teeth may be considered to...
The periodontium is a biological structure that supports the tooth in the jaw and behave as a developmental, biological, and functional unit. Teeth may be considered to be 'suspended' in their tooth sockets which provides teeth the ability to move in response to an applied load. In terms of the protection the suspension effect of the periodontal ligament may offer dental restorations, movement in an axial direction is of interest. No device or system to measure this movement is readily available, thus a novel approach had to be developed to address the questions of this research. The device developed allowed images to be taken of the participants teeth before, during and after a participant bit down on the tooth and used to measure the displacement of the tooth in image processing software. Average maximum tooth displacement from all participants of 73.8 μm (sd = 22.5 μm) were recorded. Longer application time of bite force was associated with greater cumulative tooth displacement, for a given level of force, and female participants experienced approximately 2 μm more displacement per Newton than males. The device and methods utilised in this study has shown good potential as a measurement protocol for measurement of vertical tooth movements in vivo. The response to load the teeth in this study has shown, highlighted the visco-elastic properties of the periodontal ligament and the amount of movement recorded supports the protection that controlled tooth movement offers teeth.
Topics: Male; Humans; Female; Periodontal Ligament; Bite Force; Image Processing, Computer-Assisted; Movement; Software
PubMed: 37604099
DOI: 10.1016/j.jmbbm.2023.106059 -
Molecular Biology Reports Dec 2022Periodontitis is the primary cause of irreversible destruction of the periodontium surrounding teeth. Proinflammatory cytokines are secreted by pathogens in the biofilm... (Review)
Review
Periodontitis is the primary cause of irreversible destruction of the periodontium surrounding teeth. Proinflammatory cytokines are secreted by pathogens in the biofilm and destroy the periodontium. Exosomes released into all biological fluids from saliva have enabled many innovations in the early diagnosis and treatment of periodontal diseases. This narrative review describes the role of exosomes in various diseases, and their involvement in periodontal diseases and periodontal regeneration primarily. Since guided tissue regeneration offers unpredictable results that vary according to the case, new developments in periodontal treatment are needed. Exosomes are suitable drug carriers for periodontal regeneration due to their isolation from every biological fluid, biocompatibility, low toxicity and high concentration of drugs reaching the target tissue. Exosomes obtained from mesenchymal stem cells can be used for periodontal regeneration in periodontal flaps, scaffolds, or periodontal defect areas through biomaterials such as drugs and hydrogels. Exosomes are significant in the early diagnosis and development of treatment of many diseases such as cardiovascular, neurodegenerative, diabetes and prognostic markers in cancer. Future studies are needed to elucidate the effects and possible mechanisms of exosomes in periodontitis and periodontal diseases and other systemic diseases, as they have many promises in diagnosis, treatment, and prognosis.
Topics: Humans; Exosomes; Periodontium; Periodontal Ligament; Periodontitis; Periodontal Diseases
PubMed: 36266554
DOI: 10.1007/s11033-022-08010-y -
Journal of Periodontal Research Aug 2023Periodontal ligament (PDL) and dental pulp (DP) share a common origin but have distinct biological and mechanical functions. To what extent the mechanoresponsive...
BACKGROUND AND OBJECTIVE
Periodontal ligament (PDL) and dental pulp (DP) share a common origin but have distinct biological and mechanical functions. To what extent the mechanoresponsive property of PDL can be attributed to its unique transcriptional profiles of cellular heterogeneity is unclear. This study aims to decipher cellular heterogeneity and distinct mechanoresponsive characteristics of odontogenic soft tissues and their underlying molecular mechanisms.
MATERIALS AND METHODS
A single-cell comparison of digested human periodontal ligament (PDL) and dental pulp (DP) was performed using scRNA-seq. An in vitro loading model was constructed to measure mechanoresponsive ability. Dual-luciferase assay, overexpression, and shRNA knockdown were used to investigate the molecular mechanism.
RESULTS
Our results demonstrate striking fibroblast heterogeneity across and within human PDL and DP. We demonstrated that a tissue-specific subset of fibroblasts existed in PDL exhibiting high expression of mechanoresponsive extracellular matrix (ECM) genes, which was verified by an in vitro loading model. ScRNA-seq analysis indicated a particularly enriched regulator in PDL-specific fibroblast subtype, Jun Dimerization Protein 2 (JDP2). Overexpression and knockdown of JDP2 extensively regulated the downstream mechanoresponsive ECM genes in human PDL cells. The force loading model demonstrated that JDP2 responded to tension and that knockdown of JDP2 effectively inhibited the mechanical force-induced ECM remodeling.
CONCLUSIONS
Our study constructed the PDL and DP ScRNA-seq atlas to demonstrate PDL and DP fibroblast cellular heterogeneity and identify a PDL-specific mechanoresponsive fibroblast subtype and its underlying mechanism.
Topics: Humans; Cells, Cultured; Single-Cell Gene Expression Analysis; Fibroblasts; Extracellular Matrix; Periodontal Ligament
PubMed: 37221903
DOI: 10.1111/jre.13139 -
Advanced Healthcare Materials Mar 2023The unique structure of the periodontium, including the alveolar bone, cementum, and periodontal ligament (PDL), presents difficulties for the regeneration of its...
The unique structure of the periodontium, including the alveolar bone, cementum, and periodontal ligament (PDL), presents difficulties for the regeneration of its intricate organization. Irreversible structural breakdown of the periodontium increases the risk of tooth loosening and loss. Although the current therapies can restore the periodontal hard tissues to a certain extent, the PDL with its high directionality of multiple groups with different orientations and functions cannot be reconstructed. Here, biomimetic peridontium patches (BPPs) for functional periodontal regeneration using a microscale continuous digital light projection bioprinting method is reported. Orthotopic transplantation in the mandibles shows effective periodontal reconstruction. The resulting bioengineered tissues closely resembles natural periodontium in terms of the "sandwich structures," especially the correctly oriented fibers, showing different and specific orientation in different regions of the tooth root, which has never been found in previous studies. Furthermore, after the assessment of clinically functional properties it is found that the regenerative periodontium can achieve stable tooth movement under orthodontic migration force with no adverse consequences. Overall, the BPPs promote reconstruction of the functional periodontium and the complex microstructure of the periodontal tissue, providing a proof of principle for the clinical functional treatment of periodontal defects.
Topics: Biomimetics; Periodontal Ligament; Periodontium; Tooth Root
PubMed: 36398560
DOI: 10.1002/adhm.202202169 -
Frontiers in Bioscience (Landmark... Feb 2022Orthodontic tooth movement (OTM) requires the orthodontic forces (compressive and tensile strain) to subject to the periodontal ligament and mechanosensory cells in the... (Review)
Review
Orthodontic tooth movement (OTM) requires the orthodontic forces (compressive and tensile strain) to subject to the periodontal ligament and mechanosensory cells in the periodontium and to achieve mechanotransduction by mechanoreceptors. In the context of OTM, a diverse array of signaling pathways are activated in mechanosensory cells that modulate bone resorption and formation in and models. The underlying molecular signal transduction, such as MAPK and β-Catenin signaling, that is involved in OTM, has been partially identified. It includes, but is not limited to genes and proteins which are related to osteogenesis, osteoclastogenesis, cementogenesis and inflammation. However, the interactive relation of β-Catenin and MAPK signaling remains ambiguous and diverse cross-talks are acting with each other. In this comprehensive text, we review the biology of OTM and reported experimental results on the activation/inhibition of these two signaling pathways during OTM. Here, we also focus on the implications and interplays between the MAPK and β-Catenin signaling in mechanosensory cells in response to orthodontic forces. Finally, the potential of further investigation strategies aimed at supporting orthodontic interventions are discussed. This review provides a conceptual framework for more comprehensive knowledge about signaling interaction during OTM.
Topics: Mechanotransduction, Cellular; Osteoclasts; Osteogenesis; Periodontal Ligament; Signal Transduction; Tooth Movement Techniques; beta Catenin
PubMed: 35226997
DOI: 10.31083/j.fbl2702054 -
Genesis (New York, N.Y. : 2000) Sep 2022The periodontium supports and attaches teeth via mineralized and nonmineralized tissues. It consists of two, unique mineralized tissues, cementum and alveolar bone. In... (Review)
Review
The periodontium supports and attaches teeth via mineralized and nonmineralized tissues. It consists of two, unique mineralized tissues, cementum and alveolar bone. In between these tissues, lies an unmineralized, fibrous periodontal ligament (PDL), which distributes occlusal forces, nourishes and invests teeth, and harbors progenitor cells for dentoalveolar repair. Many unanswered questions remain regarding periodontal biology. This review will focus on recent research providing insights into one enduring mystery: the precise regulation of the hard-soft tissue borders in the periodontium which define the interfaces of the cementum-PDL-alveolar bone structure. We will focus on advances in understanding the molecular mechanisms that maintain the unmineralized PDL "between a rock and a hard place" by regulating the mineralization of cementum and alveolar bone.
Topics: Bone and Bones; Periodontal Ligament; Periodontium; Stem Cells; Tooth
PubMed: 35460154
DOI: 10.1002/dvg.23474