Search Results (38)

The mechanisms driving the crown-to-root transition in tooth development remain incompletely understood, particularly the functional heterogeneity of dental epithelium. To address this gap and deconstruct this complexity, we aimed to analyze dental epithelial heterogeneity during this critical transition and to identify subpopulation-specific programs relevant to root development. We therefore established a single-cell transcriptomic atlas of the mouse molar at postnatal days 3.5 and 7.5, integrating 30,951 cells to profile the pan-tissue landscape and performing an in-depth analysis of 4323 dental epithelial cells. Our results reveal that the dental epithelium is composed of seven distinct subpopulations with a clear lineage hierarchy, originating from multipotent progenitors and bifurcating into self-renewing and differentiating trajectories. The identified particular functions of each subcluster include the following: structural maintaining progenitor that inhibits mineralization (Cluster 4), proliferation driver (Cluster 0), key signaling center (Cluster 1), terminally differentiated executing enamel formation (Cluster 3 and Cluster 6), and extracellular matrix-organizing hub (Cluster 5), communicating extensively via the Bmp, Tgf-β, and Wnt pathways. Our work defines dental epithelium as a dynamic and heterogeneous orchestrator of root morphogenesis, providing a foundational framework for understanding developmental biology and pioneering future regenerative strategies based on precise epithelial cell functions. Full article

Background and Objective: The aim of this study was to evaluate the effects of enamel matrix protein, platelet-rich fibrin (PRF), and bone graft on new bone formation beyond the skeletal system by creating calvarial bone defects in rats. The effects were assessed using histopathological and immunohistochemical analyses. Materials and Methods: In this study, calvarial bone defects were created in male Sprague Dawley rats weighing 500–550 g. The animals were randomly divided into seven groups: Control (n = 13), Emdogain (EMD, n = 13), Emdogain + Bone Graft (EMD + BG, n = 13), Platelet-Rich Fibrin (PRF, n = 13), PRF + Bone Graft (PRF + BG, n = 13), Bone Graft (BG, n = 13), and PRF + Emdogain + Bone Graft (PRF + EMD + BG, n = 13). An additional group of 36 rats was used for PRF preparation. Titanium domes were placed on the calvarial bone defects, and the animals were sacrificed after three months. Bone samples were evaluated histopathologically for new bone formation, numbers of osteoblasts and osteoclasts, angiogenesis, and fibrosis. Immunohistochemical analysis of bone formation was performed using OPG and RANKL staining kits. Data were analyzed statistically. Results: The PRF group showed a significantly higher level of moderate new bone formation compared with the PRF + BG, EMD + BG, and PRF + EMD + BG groups (p ≤ 0.05). No significant differences were observed among the groups in terms of fibrosis or angiogenesis (p > 0.05). Similarly, OPG and RANKL levels, as well as the OPG/RANKL ratio, did not differ significantly between groups (p > 0.05). Conclusions: Based on the findings of this study, the combined use of Emdogain, PRF, and bone graft appears to have beneficial effects on enhancing bone formation in calvarial defects. Full article

This study aimed to investigate the effect of enamel matrix derivatives (EMD) on the early healing biomarkers’ expression following flapless treatment. Thirty-eight patients with residual deep intrabony defects after steps 1 and 2 of periodontal therapy were randomly assigned to the test (flapless with EMD) or control group (flapless alone). Periodontal parameters were recorded at baseline and 6 months after treatment. Gingival crevicular fluid (GCF) was collected at baseline and 2 weeks after treatment to quantify the levels of biomarkers related to epithelial healing (epidermal growth factor, EGF), connective tissue healing (matrix metalloproteinase-8 [MMP-8], fibroblast growth factor [FGF], transforming growth factor-β [TGF-β]), and bone formation (osteoprotegerin [OPG]). The test group showed a significant reduction in MMP-8 levels (p = 0.039), along with significant increases in EGF (p < 0.01), FGF (p < 0.01), and OPG (p < 0.01). The control group demonstrated a significant decrease in MMP-8 (p = 0.010). No significant changes in TGF-β levels were observed in either group. At 6 months, the test group exhibited significantly greater reductions in probing pocket depth and clinical attachment level compared to the control group. This study is the first to characterize the biochemical changes following flapless treatment with EMD. These preliminary findings suggest that EMD may enhance early wound healing by modulating the expression of key regenerative biomarkers. Full article

This systematic review aimed to evaluate the effectiveness of teriparatide (TP) in guided bone regeneration (GBR). An electronic search without language or date restrictions was performed in PubMed, Web of Science, Scopus, Scielo, and gray literature for articles published until June 2025. Inclusion criteria considered studies evaluating the effect of TP on bone regeneration, analyzed using SYRCLE’s Risk of Bias tool. Twenty-four preclinical studies were included, covering diverse craniofacial models (mandibular, calvarial, extraction sockets, sinus augmentation, distraction osteogenesis, segmental defects) and employing systemic or local TP administration. Teriparatide consistently enhanced osteogenesis, graft integration, angiogenesis, and mineralization, with potentiated effects when combined with various biomaterials, including polyethylene glycol (PEG), hydroxyapatite/tricalcium phosphate (HA/TCP), biphasic calcium phosphate (BCP), octacalcium phosphate collagen (OCP/Col), enamel matrix derivatives (EMDs), autografts, allografts, xenografts (Bio-Oss), strontium ranelate, and bioactive glass. Critically, most studies presented a moderate-to-high risk of bias, with insufficient randomization, allocation concealment, and blinding, which limited the internal validity of the findings. TP shows promising osteoanabolic potential in guided bone regeneration, enhancing bone formation, angiogenesis, and scaffold integration across preclinical models. Nonetheless, its translation to clinical practice requires well-designed human randomized controlled trials to define optimal dosing strategies, long-term safety, and its role in oral and craniomaxillofacial surgical applications. Full article

The junctional epithelium, which lines the inner gingival surface, seals the gingival sulcus to block the infiltration of food debris and pathogens. The junctional epithelium is derived from the reduced enamel epithelium, consisting of late developmental stage ameloblasts and accessory cells. No prior studies have investigated whether defective ameloblast differentiation or enamel matrix formation affects junctional epithelium anatomy or function. Here, we examined the junctional epithelium in mice exhibiting amelogenesis imperfecta due to loss-of-function mutations in the major enamel matrix protein amelogenin (Amelx^−/−) or the critical enamel matrix protease KLK4 (Klk4^−/−). Histological analyses demonstrated altered morphology and cell layer thickness of the junctional epithelium in Amelx^−/− and Klk4^−/− mice as compared to wt. Immunohistochemistry revealed reduced ODAM, laminin 5, and integrin α6, all of which are critical for the adhesion of the junctional epithelium to the enamel in Amelx^−/− and Klk4^−/− mice. Furthermore, we observed altered cell–cell adhesion and increased permeability of Dextran-GFP through the mutants’ junctional epithelium, indicating defective barrier function. Reduced β-catenin and Ki67 at the base of the junctional epithelium in mutants suggest impaired mitotic activity and reduced capacity to replenish continuously desquamated epithelium. These findings highlight the essential role of normal amelogenesis in maintaining junctional epithelium homeostasis. Full article

Understanding how intricate cellular networks and signaling pathways communicate during the formation of craniofacial tissues like the palate and tooth has been the subject of intense investigation for several decades. Both organ systems undergo patterning morphogenesis and the subsequent terminal differentiation of matrix-producing cells that form biomineralized matrices like bone, enamel, dentin, and cementum. Until recently, gene expression profiles could only be assessed for a select number of cells without the context of the entire milieu of genes expressed by neighboring cells and tissues. Today, the cutting-edge field of spatial transcriptomics offers a remarkable suite of innovative technologies of multiplex gene analyses and imaging that can assess the expression of a vast library of genes that are present in situ during normal and abnormal conditions. In this review, we summarize some key technologies which have in recent years enabled an unprecedented breadth and depth of transcriptomic analyses in craniofacial development. We focus in detail on select methods that our research group has applied to better understand the cellular and molecular events that drive palate and tooth development. Our overall goal is to unravel the complexities of these unique biological systems to provide meaningful biological insights into the cellular and molecular events that drive normal development. As a work-in-progress, we strive for a deeper understanding of the temporal and spatial gene expression profiles within cells and tissues during normal and abnormal palate and tooth development. Such knowledge provides the framework for further studies that can characterize the function of new or novel genes that have the potential of serving as therapeutic targets for correcting disorders like cleft palate and tooth agenesis. Full article

Background: There is only limited research on the coronal cementum of a tooth, and the mechanisms of its forming process are not well-defined. This report presents a coronal cementum on the occlusal surfaces of enamel in an impacted wisdom tooth in a human, which is not nearly the cervical portion. Materials and Methods: The tooth (Tooth #1) was derived from a 46-year-old female. Histological analysis, including hematoxylin and eosin (HE) and toluidine blue (TB) staining, and Scanning Electron Microscopy and Energy Dispersive X-ray Spectrometer (SEM-EDS) analysis of the extracted tooth were conducted. Radiographic examination showed that Tooth #1 was horizontally impacted in the maxilla and had the apex of a single root placed between the buccal and palatal roots of Tooth #2. Results: Coronal cementum was distributed widely on the enamel, and reduced enamel epithelium was also found with enamel matrix proteins histologically. The formation of acellular cementum was observed to be more predominant than that of the cellular cementum in Tooth #1. SEM showed that the occlusal cementum connected directly with enamel. Calcium mapping revealed an almost similar occlusal cementum and enamel. In addition, the spectrum of elements in coronal cementum resembled the primary cementum according to SEM-EDS. Discussion: Thus, coronal cementogenesis in impacted human teeth might be related to the existence of reduced enamel epithelium. Full article

Periodontal regeneration is a multifaceted therapeutic approach to restore the tooth-supporting structures lost due to periodontal diseases. This manuscript explores the intricate interactions between regenerative therapies and the oral microbiome, emphasizing the critical role of microbial balance in achieving long-term success. While guided tissue regeneration (GTR), bone grafting, and soft tissue grafting offer promising outcomes in terms of tissue regeneration, these procedures can inadvertently alter the oral microbial ecosystem, potentially leading to dysbiosis or pathogenic recolonization. Different grafting materials, including autografts, allografts, xenografts, and alloplasts, influence microbial shifts, with variations in the healing timeline and microbial stabilization. Biologics and antimicrobials, such as enamel matrix derivatives (EMD) and sub-antimicrobial dose doxycycline (SDD), play a key role in promoting microbial homeostasis by supporting tissue repair and reducing pathogenic bacteria. Emerging strategies, such as enzyme-based therapies and antifouling materials, aim to disrupt biofilm formation and enhance the effectiveness of periodontal treatments. Understanding these microbial dynamics is essential for optimizing regenerative therapies and improving patient outcomes. The future of periodontal therapy lies in the development of advanced materials and strategies that not only restore lost tissues but also stabilize the oral microbiome, ultimately leading to long-term periodontal health. Full article

The natural remineralization of enamel is of major importance for oral health. In principle, early erosions (demineralization) induced by acidic beverages and foods as well as initial caries lesions can be covered and remineralized by the deposition of calcium phosphate, i.e., tooth mineral. This remineralization effect is characterized by the presence of calcium and phosphate ions in saliva that form hydroxyapatite on the enamel surface. Although it is apparently a simple crystallization, it turns out that remineralization under in vivo conditions is actually a very complex process. Calcium phosphate can form a number of solid phases of which hydroxyapatite is only one. Precipitation involves the formation of metastable phases like amorphous calcium phosphate that convert into biological apatite in a number of steps. Nanoscopic clusters of calcium phosphate that can attach on the enamel surface are also present in saliva. Thus, remineralization under strictly controlled in vitro conditions (e.g., pH, ion concentrations, no additives) is already complex, but it becomes even more complicated under the actual conditions in the oral cavity. Here, biomolecules are present in saliva, which interact with the forming calcium phosphate mineral. For instance, there are salivary proteins which have the function of inhibiting crystallization to avoid overshooting remineralization. Finally, the presence of bacteria and an extracellular matrix in plaque and the presence of proteins in the pellicle have strong influences on the precipitation on the enamel surface. The current knowledge on the remineralization of the enamel is reviewed from a chemical perspective with a special focus on the underlying crystallization phenomena and the effects of biological compounds that are present in saliva, pellicle, and plaque. Basically, the remineralization of enamel follows the same principles as calculus formation. Notably, both processes are far too complex to be understood on a microscopic basis under in vivo conditions, given the complicated process of mineral formation in the presence of a plethora of foreign ions and biomolecules. Full article

Amelogenesis imperfecta (AI) is a genetic disease characterized by poor formation of tooth enamel. AI occurs due to mutations, especially in AMEL, ENAM, KLK4, MMP20, and FAM83H, associated with changes in matrix proteins, matrix proteases, cell-matrix adhesion proteins, and transport proteins of enamel. Due to the wide variety of phenotypes, the diagnosis of AI is complex, requiring a genetic test to characterize it better. Thus, there is a demand for developing low-cost, noninvasive, and accurate platforms for AI diagnostics. This case-control pilot study aimed to test salivary vibrational modes obtained in attenuated total reflection fourier-transformed infrared (ATR-FTIR) together with machine learning algorithms: linear discriminant analysis (LDA), random forest, and support vector machine (SVM) could be used to discriminate AI from control subjects due to changes in salivary components. The best-performing SVM algorithm discriminates AI better than matched-control subjects with a sensitivity of 100%, specificity of 79%, and accuracy of 88%. The five main vibrational modes with higher feature importance in the Shapley Additive Explanations (SHAP) were 1010 cm⁻¹, 1013 cm⁻¹, 1002 cm⁻¹, 1004 cm⁻¹, and 1011 cm⁻¹ in these best-performing SVM algorithms, suggesting these vibrational modes as a pre-validated salivary infrared spectral area as a potential biomarker for AI screening. In summary, ATR-FTIR spectroscopy and machine learning algorithms can be used on saliva samples to discriminate AI and are further explored as a screening tool. Full article

Background and Objectives: This study addresses the challenge of bone regeneration in calvarial defects, exploring the efficacy of stem cell-based therapies and enamel matrix derivative (EMD) in tissue engineering. It assesses the regenerative potential of two- and three-dimensional cell constructs combined with mesenchymal stem cells (MSCs) and EMD in rabbit calvarial defects. Materials and Methods: This research involved the use of bone-marrow-derived MSCs cultured in silicon elastomer-based concave microwells to form spheroids. White rabbits were grouped for different treatments, with Group 1 as control, Group 2 receiving only EMD, Group 3 getting EMD plus stem cells, and Group 4 being treated with EMD plus stem cell spheroids. Computed tomography (CT) and microcomputed tomography (micro-CT) imaging were used for structural assessment, while histological evaluations were conducted using hematoxylin and eosin, Masson’s trichrome, and Picro-sirius red staining. Results: CT and micro-CT analyses revealed varying degrees of bone regeneration among the groups. Group 4, treated with three-dimensional MSC spheroids and EMD, showed the most significant improvement in bone regeneration. Histological analyses corroborated these findings, with Group 4 displaying enhanced bone formation and better collagen fiber organization. Conclusions: The study supported the biocompatibility and potential efficacy of three-dimensional MSC constructs combined with EMD in bone regeneration. Further investigations are needed to confirm these findings and optimize treatment protocols. Full article

The regenerative capacity of well-preserved blood clots may be enhanced by biologics like enamel matrix derivative (EMD). This retrospective analysis compares outcomes reported by three centers using different heterografts. Center 1 (C1) treated intrabony defects combining cross-linked high-molecular-weight hyaluronic acid (xHyA) with a xenograft; center 2 (C2) used EMD with an allograft combination to graft a residual pocket. Center 3 (C3) combined xHyA with the placement of a resorbable polymer membrane for defect cover. Clinical parameters, BoP reduction, and radiographically observed defect fill at 12-month examination are reported. The 12-month evaluation yielded significant improvements in PPD and CAL at each center (p < 0.001, respectively). Analyses of Covariance revealed significant improvements in all parameters, and a significantly greater CAL gain was revealed for C2 vs. C1 (p = 0.006). Radiographic defect fill presented significantly higher scores for C2 and C3 vs. C1 (p = 0.003 and = 0.014; C2 vs. C3 p = 1.00). Gingival recession increased in C1 and C3 (p = 1.00), while C2 reported no GR after 12 months (C2:C1 p = 0.002; C2:C3 p = 0.005). BoP tendency and pocket closure rate shared similar rates. Within the limitations of the study, a data comparison indicated that xHyA showed a similar capacity to enhance the regenerative response, as known for EMD. Radiographic follow-up underlined xHyA’s unique role in new attachment formation. Full article

The ideal treatment option for immature necrotic permanent teeth is regeneration of the pulp–dentin complex. Mineral trioxide aggregate (MTA), the conventional cement used for regenerative endodontic procedures, induces hard tissue repair. Various hydraulic calcium silicate cements (HCSCs) and enamel matrix derivative (EMD) also promote osteoblast proliferation. The purpose of the present study was to determine the osteogenic and dentinogenic potential of commercially distributed MTA and HCSCs when applied in combination with Emdogain gel on human dental pulp stem cells (hDPSCs). The presence of Emdogain resulted in greater cell viability, and higher alkaline phosphatase activity was detected in the Emdogain-supplemented groups in the early days of cell culture. On qRT–PCR, the groups treated, respectively, with Biodentine and Endocem MTA Premixed in the presence of Emdogain showed an increased expression of the dentin formation marker DSPP, and the group treated with Endocem MTA Premixed in the presence of Emdogain showed an upregulated expression of the bone formation markers OSX and RUNX2. In an Alizarin Red-S staining assay, all of the experimental groups exhibited a greater formation of calcium nodules when treated in combination with Emdogain. Overall, the cytotoxicity and osteogenic/odontogenic potential of HCSCs were similar to that of ProRoot MTA. The addition of the EMD increased the osteogenic and dentinogenic differentiation markers. Full article

Purpose: To systematically assess the current evidence regarding the adjunctive application of enamel matrix derivatives (EMDs) during alveolar ridge preservation (ARP) following tooth extraction. Methods: A comprehensive literature search was conducted in MEDLINE, Cochrane Library, PsycINFO, Web of Science, Google Scholar, and Scopus to identify relevant randomized controlled clinical trials (RCTs). The primary outcome parameters of this systematic review were histomorphometric and radiographic data; secondary outcomes were the feasibility of implant placement after ARP as well as patient-related outcomes such as postoperative discomfort. Results: The search identified 436 eligible articles published from 2011 to 2022, but only five were ultimately included for data extraction (146 patients). Given the substantial heterogeneity among the included studies, no meta-analysis could be performed. The authors’ qualitative analysis showed marginally improved outcomes regarding an increased percentage of new bone formation after tooth extraction and a reduction in postoperative discomfort. Conclusions: Given the potential value of EMDs in other fields of regenerative dentistry, more consideration should be given to EMDs as an adjunctive treatment option in ARP. However, more well-controlled randomized clinical trials are necessary to evaluate the exact potential and impacts of EMDs. Full article

Dental enamel is a specialized tissue that has adapted over millions of years of evolution to enhance the survival of a variety of species. In humans, enamel evolved to form the exterior protective layer for the crown of the exposed tooth crown. Its unique composition, structure, physical properties and attachment to the underlying dentin tissue allow it to be a resilient, although not self-repairing, tissue. The process of enamel formation, known as amelogenesis, involves epithelial-derived cells called ameloblasts that secrete a unique extracellular matrix that influences the structure of the mineralizing enamel crystallites. There are over 115 known genetic conditions affecting amelogenesis that are associated with enamel phenotypes characterized by either a reduction of enamel amount and or mineralization. Amelogenesis involves many processes that are sensitive to perturbation and can be altered by numerous environmental stressors. Genetics, epigenetics, and environment factors can influence enamel formation and play a role in resistance/risk for developmental defects and the complex disease, dental caries. Understanding why and how enamel is affected and the enamel phenotypes seen clinically support diagnostics, prognosis prediction, and the selection of treatment approaches that are appropriate for the specific tissue defects (e.g., deficient amount, decreased mineral, reduced insulation and hypersensitivity). The current level of knowledge regarding the heritable enamel defects is sufficient to develop a new classification system and consensus nosology that effectively communicate the mode of inheritance, molecular defect/pathway, and the functional aberration and resulting enamel phenotype. Full article