Dentin Tissue Research Articles

Personalized 3D-Printed Scaffolds with Multiple Bioactivities for Bioroot Regeneration.

Recent advances in 3D printing offer a prospective avenue for producing transplantable human tissues with complex geometries; however, the appropriate 3D-printed scaffolds possessing the biological compatibility for tooth regeneration remain unidentified. This study proposes a personalized scaffold of multiple bioactivities, including induction of stem cell proliferation and differentiation, biomimetic mineralization, and angiogenesis. A brand-new bioink system comprising a biocompatible and biodegradable polymer is developed and reinforced with extracellular matrix generated from dentin tissue (treated dentin matrix, TDM). Adding TDM optimizes physical properties including microstructure, hydrophilicity, and mechanical strength of the scaffolds. Proteomics analysis reveals that the released proteins of the 3D-printed TDM scaffolds relate to multiple biological processes and interact closely with each other. Additionally, 3D-printed TDM scaffolds establish a favorable microenvironment for cell attachment, proliferation, and differentiation in vitro. The 3D-printed TDM scaffolds are proangiogenic and facilitate whole-thickness vascularization of the graft in a subcutaneous model. Notably, the personalized TDM scaffold combined with dental follicle cells mimics the anatomy and physiology of the native tooth root three months after in situ transplantation in beagles. The remarkable in vitro and in vivo outcomes suggest that the 3D-printed TDM scaffolds have multiple bioactivities and immense clinical potential for tooth-loss therapy.

In Vitro and In Vivo Biological Assessments of 3D-Bioprinted Scaffolds for Dental Applications.

Three-dimensional (3D) bioprinting is a unique combination of technological advances in 3D printing and tissue engineering. It has emerged as a promising approach to address the dilemma in current dental treatments faced by clinicians in order to repair or replace injured and diseased tissues. The exploration of 3D bioprinting technology provides high reproducibility and precise control of the bioink containing the desired cells and biomaterial over the architectural and dimensional features of the scaffolds in fabricating functional tissue constructs that are specific to the patient treatment need. In recent years, the dental applications of different 3D bioprinting techniques, types of novel bioinks, and the types of cells used have been extensively explored. Most of the findings noted significant challenges compared to the non-biological 3D printing approach in constructing the bioscaffolds that mimic native tissues. Hence, this review focuses solely on the implementation of 3D bioprinting techniques and strategies based on cell-laden bioinks. It discusses the in vitro applications of 3D-bioprinted scaffolds on cell viabilities, cell functionalities, differentiation ability, and expression of the markers as well as the in vivo evaluations of the implanted bioscaffolds on the animal models for bone, periodontal, dentin, and pulp tissue regeneration. Finally, it outlines some perspectives for future developments in dental applications.

A Study of the Effects of Medical Dental Laser and Diamond Drill on Dentin Tissue during Dental Restoration Based on Spectral Imaging and Multivariate Analysis of Synchrotron FTIR Microspectroscopy Data

In our work, the effect of a dental Er:YAG pulsed laser and a diamond cylindrical drill with a turbine handpiece on dentin tissue was studied using spectral imaging. The combination of spectral imaging of FTIR microspectroscopy data and subsequent multivariate analysis (hierarchical cluster analysis (HCA) and principal component analysis (PCA)) was shown to unambiguously detect visually indistinguishable structural changes occurring in the hard dental tissue (dentin) depending on the method used for their pre-processing, and to classify and differentiate the identified features at the submicron level with high spatial resolution. The detectable spectral transformations indicate that the preparation of dental tissue with a dental laser leads to significant changes in the organic components of dentin, which may affect adhesion. The use of a diamond cylindrical drill with a turbine handpiece is characterized by a larger area (depth) of the altered hard tissue than in the case of a dental laser for dental cavity preparation. The observed redistribution of the phase composition of the inorganic component in the tissue is associated with the emergence of additional phases of weak calcium phosphates, and changes in the organic component with transformations in the secondary structure of proteins. Active use of the proposed integrated approach in the future will clarify the areas of its applicability to the analysis of biological tissues and pathologies in them, which will help in the clinical setting to choose the optimal personalized approach for patients.

Odontoma and other congenital dental anomalies: Implications for forensic identification.

Forensic odontology plays a crucial role in establishing the identity in mass disasters and criminal cases with high accuracy. Dental anomalies and features help in such situations. Congenital and developmental dental anomalies can be easily documented to establish distinctive and individualistic characteristics of an individual. The location, number of teeth involved, and the type of anomaly vary between individuals. Similarly, dental malformations also assist greatly in the identification process. Many types of dental anomalies have been studied in the past for their individualistic characteristics in forensic examinations. One such dental anomaly is odontoma, which is a benign odontogenic malformation. This malformation may also help in the identification of the deceased, when recorded and examined accurately. An odontome is a malformed teeth-like structures consisting of enamel, dentin, and pulpal tissue, formed due to the growth of completely differentiated epithelial and mesenchymal cells. If antemortem (AM) dental records incorporate information regarding odontomes and other dental anomalies, including in radiographs, orthopantomograms or microradiographs, positive identification may be established by comparison of these records with postmortem (PM) records. In the present communication, a rare case of compound composite odontoma in the anterior mandible with multiple denticles has been discussed with a brief overview of congenital and developmental dental anomalies. The authors emphasize the importance of such rare dental anomalies and malformations which may be used for identifying the deceased in mass disasters and forensic identification.

Tideglusib-incorporated nanofibrous scaffolds potently induce odontogenic differentiation.

Pulp-Dentin regeneration is a key aspect of maintain tooth vitality and enabling good oral-systemic health. This study aimed to investigate a nanofibrous scaffold loaded with a small molecule i.e. Tideglusib to promote odontogenic differentiation. Tideglusib (GSK-3β inhibitor) interaction with GSK-3β was determined using molecular docking and stabilization of β-catenin was examined by confocal microscopy. 3D nanofibrous scaffolds were fabricated through electrospinning and their physicochemical characterizations were performed. Scaffolds were seeded with mesenchymal stem cells or pre-odontoblast cells to determine the cells proliferation and odontogenic differentiation. Our results showed that Tideglusib (TG) binds with GSK-3β at Cys199 residue. Stabilization and nuclear translocation of β-catenin was increased in the odontoblast cells treated with TG. SEM analysis revealed that nanofibers exhibited controlled architectural features that effectively mimicked the natural ECM. UV-Vis spectroscopy demonstrated that TG was incorporated successfully and released in a controlled manner. Both kinds of biomimetic nanofibrous matrices (PCLF-TG100, PCLF-TG1000) significantly stimulated cells proliferation. Furthermore, these scaffolds significantly induced dentinogenic markers (ALP, and DSPP) expression and biomineralization. In contrast to current pulp capping material driving dentin repair, the sophisticated, polymeric scaffold systems with soluble and insoluble spatiotemporal cues described here can direct stem cell differentiation and dentin regeneration. Hence, bioactive small molecule-incorporated nanofibrous scaffold suggests an innovative clinical tool for dentin tissue engineering.

BDNF/TrkB Is a Crucial Regulator in the Inflammation-Mediated Odontoblastic Differentiation of Dental Pulp Stem Cells.

The odontoblastic differentiation of dental pulp stem cells (DPSCs) associated with caries injury happens in an inflammatory context. We recently demonstrated that there is a link between inflammation and dental tissue regeneration, identified via enhanced DPSC-mediated dentinogenesis in vitro. Brain-derived neurotrophic factor (BDNF) is a nerve growth factor-related gene family molecule which functions through tropomyosin receptor kinase B (TrkB). While the roles of BDNF in neural tissue repair and other regeneration processes are well identified, its role in dentinogenesis has not been explored. Furthermore, the role of BDNF receptor-TrkB in inflammation-induced dentinogenesis remains unknown. The role of BDNF/TrkB was examined during a 17-day odontogenic differentiation of DPSCs. Human DPSCs were subjected to odontogenic differentiation in dentinogenic media treated with inflammation inducers (LTA or TNFα), BDNF, and a TrkB agonist (LM22A-4) and/or antagonist (CTX-B). Our data show that BDNF and TrkB receptors affect the early and late stages of the odontogenic differentiation of DPSCs. Immunofluorescent data confirmed the expression of BDNF and TrkB in DPSCs. Our ELISA and qPCR data demonstrate that TrkB agonist treatment increased the expression of dentin matrix protein-1 (DMP-1) during early DPSC odontoblastic differentiation. Coherently, the expression levels of runt-related transcription factor 2 (RUNX-2) and osteocalcin (OCN) were increased. TNFα, which is responsible for a diverse range of inflammation signaling, increased the levels of expression of dentin sialophosphoprotein (DSPP) and DMP1. Furthermore, BDNF significantly potentiated its effect. The application of CTX-B reversed this effect, suggesting TrkB`s critical role in TNFα-mediated dentinogenesis. Our studies provide novel findings on the role of BDNF-TrkB in the inflammation-induced odontoblastic differentiation of DPSCs. This finding will address a novel regulatory pathway and a therapeutic approach in dentin tissue engineering using DPSCs.

INVESTIGATION OF THE ADHESIVE ABILITY OF ZINC-PHOSPHATE CEMENTS TO THE DENTIN OF THE TOOTH

Improving the reliability of fixing fixed orthopedic structures of dentures is an urgent issue at all times. Due to the increase in the variety of materials in the modern world, the choice for dentists has become even more difficult. Various types of fixing materials are used in the clinic, and their choice depends on the specifics of the clinical situation and the material of the structure from which it is made.
 One of the types of cements are zinc-phosphate, which are used in practice for a long time and are characterized by sufficient adhesion strength. Representatives of this group have become less popular in the orthopedic dental clinic, since its properties are considered insufficiently satisfactory. Undoubtedly, any fixing material has both pros and cons. It is possible to get high-quality treatment with a dental prosthesis in the oral cavity if the fixing materials are correctly selected, the principles of preparation are observed and a high-quality adhesive protocol is performed.
 The article describes a study of the adhesive ability of individual zinc-phosphate cements, which was carried out in laboratory conditions at the technical base of LLC "Tselit" Voronezh. 30 teeth of the chewing group were used, which were divided into groups according to the use of materials: "NeoDent" LLC Celit, "VISCIN" LLC Raduga-R, "Adhesor" SpofaDental (Czech Republic).
 The strength of adhesion was studied using the method - shear test, which determines the strength of the connection of dentine tissue with zinc-phosphate cement.

Investigation of the effect of indirect pulp capping materials on dentin mineral density

Aim: To evaluate the potential of inducing mineral density changes of indirect pulp capping materials applied to demineralized dentin. Methods: A total of 50 cavities were prepared, 5 in each tooth, in extracted ten molars without caries, impacted or semi-embedded. The cavities were scanned by microcomputed tomography (μ-CT) after creating artificial caries by microcosm method (pre-treatment). Each cavity was subjected to one of 5 different experimental conditions: control (dental wax), conventional glass ionomer cement (Fuji IX GP Extra), resin-modified calcium silicate (TheraCal LC), resin-modified calcium hydroxide (Ultra-Blend Plus), MTA (MM-MTA) and the samples were kept under intrapulpal pressure using simulated body fluid for 45 days. Then, the second μ-CT scan was performed (post-treatment), and the change in dentin mineral density was calculated. Afterward, elemental mapping was performed on the dentinal surfaces adjacent to the pulp capping agents of 5 randomly selected samples using energy dispersive X-ray spectroscopy (EDS) apparatus attached to a scanning electron microscope (SEM). The Ca/P ratio by weight was calculated. Friedman test and Wilcoxon Signed Ranks test were used to analyze the data. Results: There was a significant increase in mineral density values of demineralized dentin after treatment for all material groups (p<0.05). Resin-modified calcium silicate had similar efficacy to MTA and conventional glass ionomer cement, but was superior to resin-modified calcium hydroxide in increasing the mineral density values of demineralized dentin. Conclusions: Demineralized dentin tissue that is still repairable can be effectively preserved using materials with remineralization capability.

The accuracy of quantifying the degree of hard tissue calcification using an electron probe micro analyzer, micro-focus X-ray computed tomography, and tissue sectioning methods

ObjectivesMicro-focus X-ray computed tomography (μCT) helps evaluate specimens without destroying it. However, its accuracy of quantifying bone mineral density remains to be fully elucidated. We aimed to verify the accuracy of calcification assessed by μCT, by comparing the images of identical specimens obtained via different methods such as μCT and electron probe micro analyzer (EPMA) analyses. MethodsThe maxillae, mandibles, and tibiae of five-week-old male mice were analyzed. Calcification density was analyzed using μCT. The right sides of the specimens were decalcified and processed for Azan staining. The left side of the specimens underwent elemental mapping for Ca, Mg, and P using EPMA. ResultsμCT revealed a significant increase in calcification levels in the following order: enamel, dentin, cortical bone, and trabecular bone. These results reflected the Ca and P levels observed in the EPMA analyses. μCT demonstrated significant differences in the degree of calcification among the enamel tissues or dentin tissues, except for dentin in the maxillary incisors and molars. However, EPMA analysis did not demonstrate significant differences in the Ca and P levels among the same tissue samples. ConclusionsEPMA elemental analysis can be used to measure Ca and P levels for evaluating the calcification rate of hard tissues. Additionally, the study results validate the evaluation of calcification density via μCT. Furthermore, μCT can evaluate even minute differences in calcification rates compared with EPMA analysis.

Using Dental Pulp Cells Derived from Stem Cells to Promote Dentin and Pulp Tissue Regeneration in Severe Tooth Decay: A Translational Research Method

Severe tooth decay is considered to be one of the major threats to dental health, which usually leads to the loss of tooth structure and, thus, its functional impairment. Traditional methods of dental treatment, like extractions, root canals, and fillings, may further contribute to more complications and do not really replace natural characteristics of teeth. In view of providing a biological answer to this common problem, the present study explores the potential of DPCs produced from stem cells for the regeneration of dentin and pulp tissue. The aims of this study were to produce and isolate DPCs, produce appropriate scaffold materials, and evaluate their in vivo and in vitro regeneration capacities. As opposed to the in vivo studies, which evaluated integration and functionality of regenerated tissues in animal models, studies in vitro focused on cell viability, proliferation, and odontoblastic differentiation. It has succeeded in establishing effective scaffold environments that would help in regeneration of dental tissues and demonstrated the ability of DPCs to differentiate into odontoblast-like cells. Further, it has developed standardized techniques for isolating and culturing DPCs. The study also provides a comprehensive evaluation framework through histological and functional assessments and will therefore play an important role in progress of regenerative dentistry. The results indicated that DPCs had high in vitro proliferation and cell survival. Further, they showed prominent mineral deposition and expression of odontoblastic markers like DMP1 and DSPP. High integration scores and functional restoration comparable to natural dentin testified that the regenerated tissues integrated very well with native tooth structures in vivo. These results open the way for DPC-based treatments to achieve structurally and functionally sound dental tissue regeneration.

Guided Tissue Regeneration in Class IV External Cervical Resorption: A Case Report

External cervical resorption (ECR) is a type of dental resorption that originates from the loss of the cementum's protective layer. The direct exposure of dentin to the periodontal ligament may lead to the invasion of clastic cells through an entry point on the external root surface into the dentinal tissue, causing resorption. Depending on the extension of ECR, different treatments are proposed. Although the literature presents distinct materials and methods for restoring ECR areas, an existing gap is related to care in the treatment of the supporting periodontal tissue. Guided tissue regeneration (GTR)/guided bone regeneration includes the stimulation of bone formation in bone defects using different types of membranes (resorbable and nonresorbable), regardless of its association with bone substitutes or grafts. Despite the benefits of guided bone regeneration, the application of this method in cases of ECR is still under-explored in the literature. Thus, the present case report uses GTR with xenogenic material and polydioxanone membrane in a case of class IV ECR. The success of the present case is related to the correct diagnosis and treatment plan. Complete debridement of resorption areas and restoration with biodentine were effective in tooth repair. GTR contributed to the stabilization of supporting periodontal tissues. The association of the xenogeneic bone graft with the polydioxanone membrane proved to be a viable option for restoring the health of the periodontium.

Comparative evaluation of the effect of 2% graphene oxide and 5% hydroxyapatite nanoparticles in isolation and in combination on micro tensile bond strength of 5th generation adhesive

Graphene is the thinnest, strongest and stiffest imaginable material. The biocompatible property of graphene oxide can initiate and facilitate cell adhesion, proliferation and differentiation of periodontal ligament, osteogenic and oral epithelial cells. Furthermore, the antibiofilm and anti-adhesion properties of graphene oxide in prevention of dental biofilm infections, dental caries, dental erosion as well as for implant surface modification and as anti-quorum sensing agent. Composites are most often utilised materials for restoration in the field of dentistry due to adhesive resins' improved mechanical and cosmetic properties. To safeguard the dentin and prevent dental cavities, dentin adhesives are utilised to affix hydrophobic resin composites to hydrophilic dentin tissue. Dental adhesives have a harder time adhering to dentin because it contains more water and is less mineralized than enamel. This makes the method more sensitive. As a result, it was chosen to assess and contrast the impact of 5% Hydroxyapatite nanoparticles and 2% Graphene oxide nanoparticles, both separately and together, on the Micro tensile bond strength of 5th generation adhesive. Graphene oxide is the most versatile form of Graphite in structural and functional configuration. Graphene oxide possess extraordinary physical, chemical, optical, electrical and mechanical properties. Among the graphene family nanomaterials, the reduced form of Graphite adding the oxygenated functional group to the structure increases the surface area and therefore exhibits enviable excellent interaction ability with metal and ions as well as organic species. Graphene oxide in dentistry has provided outstanding results in antimicrobial action, regenerative dentistry, bone tissue engineering, drug delivery, physicochemical property, enhancement of dental biomaterials and oral cancer treatment.

Evaluation of Er,Cr:YSGG laser technique for fiber post removal of endodontically treated teeth using micro-computed tomography.

Various clinical techniques such as removal kits, ultrasonic tips, burs, and drills, have been used for fiber post removal in endodontically treated teeth. In most clinical cases, the dental practitioners prefer to use ultrasonic tips, despite the heat generation and the formation of microcracks induced in the radicular dentin. The purpose of this study was to investigate the effectiveness of using erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser (2780 nm) as an alternative fiber post removal technique and to compare it to an ultrasonic method using micro-computed tomography (micro-CT). The operating parameters of the X-ray tube were set to 50 kVp and 300 mA. This approach allowed the generation of 2D lateral projections that were then used to reconstruct the 3D volume in DICOM format. Fiber posts were removed from 20 endodontically treated single-rooted premolars (n = 10) using an ultrasonic vibrator with diamond-coated ultrasonic tip (control method), or Er,Cr:YSGG laser irradiation protocol; average power 2.5 W, repetition rate 20 Hz, pulse duration 140 μs, 40% air and 20% water, and close-contact mode. The number of sections with newly formed microcracks, the loss of dentinal tissue, the amount of the residual resin cement, and the removal time were evaluated for both methods. The data were analyzed using paired t-test, Wilcoxon signed-rank and Mann-Whitney U tests at level of significance a = .05. In the laser-treated group the parameters regarding microcracks formation (21 ± 16) and removal time (4.7 ± 1.1 min) were advantageous compared to the ultrasonic-treated group (42 ± 27 and 9.2 ± 1.0 min, respectively), indicating that Er,Cr:YSGG laser could be an alternative fiber post removal technique.

Evaluation of Dentinal Thickness and Remaining Dentine Volume around Root Canals Using Cone-Beam Computed Tomography Scanning.

The remaining dentinal thickness is a significant factor to deal with when planning post-endodontic treatment. To assess the changes in the root canal dentinal thickness of intact and endodontically treated teeth using CBCT scans in the coronal, middle, and apical third of the root canal. Three hundred CBCT scans for three age groups were analyzed to study the dentinal thickness pre- and post-endodontic treatment. The dentinal thickness (DT) was measured along the buccal, mesial, distal, and lingual/palatal walls from the inner surface of the root canal to the outer surface in mm. Statistical analysis was set at 0.05. The results of this study showed that the buccal, palatal, distal, and mesial dentinal thickness in intact and endodontically treated teeth is different. The differences were statistically significant when comparing the parameters of "healthy" and "treated" teeth (p < 0.05). There were no statistically significant differences in indicators associated with age (p > 0.05). In the coronal third of the root canal, the least amount of dentin tissue lost was 4.2% for mandibular canines. The dentinal thickness in the coronal and middle third of the root decreases significantly more than the apical third. The most loss of dentine volume was among molar teeth, and the remaining dentinal thickness was less than 1 mm, which would increase the risk of complication while preparing the canal for a post.

Comparative microstructural study on the teeth of Mesozoic birds and non-avian dinosaurs.

Although it is commonly considered that, in birds, there is a trend towards reduced dentition, teeth persisted in birds for 90 Ma and numerous macroscopic morphologies are observed. However, the extent to which the microstructure of bird teeth differs from other lineages is poorly understood. To explore the microstructural differences of the teeth of birds in comparison with closely related non-avialan dinosaurs, the enamel and dentine-related features were evaluated in four Mesozoic paravian species from the Yanliao and Jehol biotas. Different patterns of dentinal tubular tissues with mineralized extensions of the odontoblast processes were revealed through the examination of histological sectioning under electron microscopy. Secondary modification of the tubular structures, forming reactive sclerotic dentin of Longipteryx, and the mineralization of peritubular dentin of Sapeornis were observed in the mantle dentin region. The new observed features combined with other dentinal-associated ultrastructure suggest that the developmental mechanisms controlling dentin formation are quite plastic, permitting the evolution of unique morphologies associated with specialized feeding behaviours in the toothed birds. Proportionally greater functional stress placed on the stem bird teeth may have induced reactive dentin mineralization, which was observed more often within tubules of these taxa. This suggests modifications to the dentin to counteract potential failure.

ESTIMATION OF REMAINING DENTIN THICKNESS UNDER DENTIN CARIES WITH CBCT, RADIOGRAPHS AND DIGITAL CALIPER IN PERMANENT TEETH - AN INVITRO STUDY

Background: In order to avoid damaging the dental pulp from mechanical injury and inammatory agents, operators are recommended to remove just infected dentin while maintaining affected and sound dentin. As a result, maximum dentin tissue must be preserved. This study aims to identify a logistic and accurate link between the amounts of actual remaining dentine thickness and the radiographic remaining dentine thickness before starting caries excavation, thereby lowering the incidences of post-operative sensitivity and direct pulpal exposure. In a three-stage experiment, 24 extracted human teeth were Material and Methodology: evaluated using three different techniques: digital radiography(RVG), cone beam computed tomography(CBCT), and using digital caliper after hand excavation of any remaining caries. The results were compared and statistical analysis was performed for each tooth. The difference among the Statistical analysis: groups was analyzed by post hoc Turkey and analysis of variance tests. A P &lt; 0.05 was considered statistically signicant. The results Results: indicated no signicant difference between actual clinical (digital caliper) and CBCT measurements (P=0.054) but a signicant difference was found between actual clinical and periapical radiographs. It is imprecise to Conclusion: estimate the remaining dentine thickness using routine periapical radiographs; a reliable and affordable method still has to be developed.

Mechanism of Pulp Regeneration Based on Concentrated Growth Factors Regulating Cell Differentiation.

Concentrated growth factors (CGF) is the newest generation platelet concentrate product, which has been reported to promote the proliferation and differentiation of human dental pulp cells (hDPCs). However, the effect of liquid phase of CGF (LPCGF) has not been reported. This study was aimed to evaluate the influence of LPCGF on the biological properties of hDPCs, and to explore the in vivo mechanism of dental pulp regeneration based on the hDPCs-LPCGF complex transplantation. It was found that LPCGF could promote the proliferation, migration and odontogenic differentiation of hDPCs, and 25% LPCGF induced the most mineralization nodule formation and the highest DSPP gene expression. The heterotopic transplantation of the hDPCs-LPCGF complex resulted in the formation of regenerative pulp tissue with newly formed dentin, neovascularization and nerve-like tissue. Together, these findings provide key data on the effect of LPCGF on the proliferation, migration, odontogenic/osteogenic differentiation of hDPCs, and the in vivo mechanism of hDPCs-LPCGF complex autologous transplantation in pulp regeneration therapy.

Using Odontoblasts Derived from Dog Endometrial Stem Cells Encapsulated in Fibrin Gel Associated with BMP-2 in a Rat Pulp-Capping Model

This study aimed to treat dental injuries by utilizing one of the most advanced tissue engineering techniques. In this study, an in vitro model was employed to investigate the proliferation and odontogenic differentiation of canine endometrial stem cells (C-EnSCs). Furthermore, the dentin regeneration potential of odontoblast like-cells (OD) derived from C-EnSCs was assessed in rats. The C-EnSCs were isolated by the enzymatic method and identified by flow cytometry. The C-EnSCs were encapsulated in fibrin gel associated with signaling factors to create the proper conditions for cell growth and differentiation. Then, the OD cells were associated with bone morphologic protein-2 (BMP-2) to promote dentin formation in vivo. The animal model used to evaluate the regenerative effect of cells and biomaterials included the preparation of the left maxillary first molar of rats for direct pulp capping operation. Animals were divided into four groups: group 1, a control group without any treatment, group 2, which received fibrin, group 3, which received fibrin with ODs (fibrin/ODs), and group 4, which received fibrin with ODs and BMP-2 (fibrin/ODs/BMP-2). The morphological observations showed the differentiation of C-EnSCs into adipose, bone, neural cells, and ODs. Furthermore, the histomorphometric data of the treated teeth showed how fibrin gel and BMP2 at a concentration of 100 ng/mL provided an optimal microenvironment for regenerating dentin tissue in rats, which was increased significantly with the presence of OD cells within eight weeks. Our study showed that using OD cells derived from C-EnSCs encapsulated in fibrin gel associated with BMP2 can potentially be an appropriate candidate for direct pulp-capping and dentin regeneration.

ASPECTS OF ETIOLOGY, DIAGNOSIS AND TREATMENT OF PREERUPTIVE INTRACORONAL RESORPTION IN CHILDREN (LITERATURE REVIEW)

The purpose of this work was to study the literature on research papers by domestic and foreign authors describing pre-eruption intracoronal resorption. The review discusses issues that indicate the presence of a resorption process in permanent teeth before their eruption. This lesion of the hard tissues of the teeth is rare, and the etiology of this process is not fully understood. The processes of tooth resorption can be observed outside on the root surface or inside the pulp chamber, and if a permanent tooth is involved in this process, this indicates the development of pathological resorption. Along with dental caries and periodontal disease in childhood, processes of resorption of coronal dentin tissue in unerupted permanent teeth can be observed. Some authors describe internal resorption, ectopic positioning, external resorption, and origin from developmental pits on the occlusal surface as etiological factors for preeruptive intracoronal resorption, but other authors suggest that the etiology of this lesion remains poorly understood. The main diagnostic method is an x-ray examination, in which preeruptive intracoronal resorption is accidentally detected and other research methods are additionally used. Histological examination reveals osteoclasts, multinucleated giant cells, macrophages, and serrated edges in this lesion, which may possibly enter the developing tooth from the surrounding bone or through breaks in the dental follicle or enamel epithelium. With a small lesion and if the tooth is close to eruption, periodic X-ray control is necessary, and after eruption, when occlusal access is reached, the defect is restored in order to minimize the attachment of the carious process.

Traumatic effects of infant oral mutilation on odontogenesis: A case report.

Infant oral mutilation (IOM), widely practiced in East Africa, involves gouging of unerupted teeth to allegedly cure childhood diseases. Non-sterile instruments are often used during IOM, causing immediate and long-term complications, including dental defects, infection, and death. This is a case report describing how IOM affected tooth development and oral health in a four-year-old Somali girl who, three years prior, underwent IOM of her primary mandibular canines. Two affected primary mandibular canines (denoted M* and R*) were extracted from the patient at age four because they were dysmorphic, nonfunctional, and at risk of further pathology. Tooth M* was moderately affected, with reduced root length and blunt root tip, though enamel and dentin thickness, densities, and tissue organization were within normal range by micro-computed tomography. Tooth R* was dramatically diminished in size and severely dysmorphic. By histology, dentinal tubules were within normal parameters in affected canines, and acellular cementum was thin but with undiminished mineral density and normal histological appearance. Permanent canines appeared unaffected in radiographs. This case demonstrates that IOM affected odontogenesis of primary canines, although formation of enamel, dentin and cementum proceeded despite the trauma. Further investigation of IOM and its effects on oral and systemic health can aid in advocacy efforts to eradicate this practice.