Hypoxia-inducible factor 1α induces osteo/odontoblast differentiation of human dental pulp stem cells via Wnt/β-catenin transcriptional cofactor BCL9

Accelerated dental pulp mineralization is a common complication in avulsed/luxated teeth, although the mechanisms underlying this remain unclear. We hypothesized that hypoxia due to vascular severance may induce osteo/odontoblast differentiation of dental pulp stem cells (DPSCs). This study examined the role of B-cell CLL/lymphoma 9 (BCL9), which is downstream of hypoxia-inducible factor 1α (HIF1α) and a Wnt/β-catenin transcriptional cofactor, in the osteo/odontoblastic differentiation of human DPSCs (hDPSCs) under hypoxic conditions. hDPSCs were isolated from extracted healthy wisdom teeth. Hypoxic conditions and HIF1α overexpression induced significant upregulation of mRNAs for osteo/odontoblast markers (RUNX2, ALP, OC), BCL9, and Wnt/β-catenin signaling target genes (AXIN2, TCF1) in hDPSCs. Overexpression and suppression of BCL9 in hDPSCs up- and downregulated, respectively, the mRNAs for AXIN2, TCF1, and the osteo/odontoblast markers. Hypoxic-cultured mouse pulp tissue explants showed the promotion of HIF1α, BCL9, and β-catenin expression and BCL9-β-catenin co-localization. In addition, BCL9 formed a complex with β-catenin in hDPSCs in vitro. This study demonstrated that hypoxia/HIF1α-induced osteo/odontoblast differentiation of hDPSCs was partially dependent on Wnt/β-catenin signaling, where BCL9 acted as a key mediator between HIF1α and Wnt/β-catenin signaling. These findings may reveal part of the mechanisms of dental pulp mineralization after traumatic dental injury.

Portland Cement: An Overview as a Root Repair Material

Portland cement (PC) is used in challenging endodontic situations in which preserving the health and functionality of pulp tissue is of considerable importance. PC forms the main component of mineral trioxide aggregate (MTA) and demonstrates similar desirable properties as an orthograde or retrograde filling material. PC is able to protect pulp against bacterial infiltration, induce reparative dentinogenesis, and form dentin bridge during the pulp healing process. The biocompatibility, bioactivity, and physical properties of PC have been investigated in vitro and in animal models, as well as in some limited clinical trials. This paper reviews Portland cement’s structure and its characteristics and reaction in various environments and eventually accentuates the present concerns with this material. This bioactive endodontic cement has shown promising success rates compared to MTA; however, considerable modifications are required in order to improve its characteristics and expand its application scope as a root repair material. Hence, the extensive chemical modifications incorporated into PC composition to facilitate preparation and handling procedures are discussed. It is still important to further address the applicability, reliability, and cost-effectiveness of PC before transferring into day-to-day clinical practice.

Clinical insights into the three-dimensional anatomy of cheek teeth in alpacas based on micro-computed tomography - Part 2: Maxillary cheek teeth

Background Scientific knowledge regarding alpaca dentistry is relatively limited despite its clinical implications. The present gap in available supportive data leads to limited treatment options for dental pathology in alpacas in comparison to other species. The main goal of this study was to gain novel insights into the general and pulp morphology of maxillary cheek teeth to allow development of more advanced treatment strategies in the future. Also, the risk of causing pulp exposure when floating maxillary cheek teeth was of particular interest. Concurent research focusing on the anatomy of mandibular cheek teeth has been performed accordingly. The results obtained in mandibular teeth are expected to be non-extrapolatable because of the structural differences between mandibular and maxillary teeth. Results Pulp morphology of maxillary cheek teeth showed great variation. A common pulp chamber was identified in 46/83 (55.4%) teeth with a mean dental age of 2 years and 7 months (± 2 years and 5 months). Pulpal segmentation was more commonly observed in teeth of increasing age. Full columnar segmentation was seen in 33/69 teeth (47.8%), whereas within-column segmentation was observed in 36/83 teeth (43.4%). Age and degree of segmentation of the pulpal tissue varied greatly according to Triadan position. Physical contact between roots of adjacent teeth was found in the majority of examined molars (range 82–94%) which resulted in morphological adaptations at the level of the root tips. The measured sub-occlusal dentinal thickness was as low as 0.46 mm above pulp horn 2 in a 14 years and 11 months old Triadan 09, emphasizing the risk of pulp exposure attributed to dental floating. Conclusion This study offers an objective description of age-dependent maxillary cheek teeth pulp morphology in alpacas. Current findings are of great value to provide a basis for the development of tooth-saving techniques as a treatment for dental disease in this species. Observed physical contact between the roots of different examined molars may be a facilitating factor in the spread of apical infection in chronically diseased cases. Finally, a conservative approach regarding dental floating is recommended in order to avoid iatrogenic damage to pulp tissue.

SELECTION OF OBTURATIONS MATERIALS IN PULPECTOMY TREATMENT OF DECIDUOUS TEETH

Introduction: Pulpectomy is the procedure of taking the entire pulp tissue from all the roots and corona of a tooth. There are several materials for obturation / root canal fillers in deciduous teeth, namely zinc oxide eugenol (ZOE), calcium hydroxide and iodoform paste a mixture of calcium hydroxide. A 6 year old boy patient came to RSGM with his parents seeking for treatment a tooth with a large cavity in the upper left posterior region and had been pain before. Intraoral examination revealed deep caries in the occlusal tooth 65 which reaching the pulp, percussion (-), palpation (-), mobility (-), vitality (-). Radiographic examination of tooth 65 showed a radiolucent image that had reached the pulp and the root canals had not yet undergone resorption. The diagnosis of this case was pulp necrosis at tooth 65. Case management: The treatment plan to be carried out was non-vital pulpectomy on tooth 65 and used technique non-vital pulpectomy because the tooth had already necrosis. Discussion: The filler used is ZOE. The reason for choosing this material was because it was indications for the use of ZOE material for teeth with necrosis. Conclussion: ZOE has anti-inflammatory and analgesic properties that can reduce pain

Use of odontotropic material in treatment of traumatic pulpitis in experiment

The problem of diagnosis and effective treatment of one of the most common complications of dental caries, such as pulpitis, including pediatric patients, is still quite relevant at the present time. Considering anatomy-physiological and age-related features of temporary and permanent teeth in children, the rapid and aggressive course of the carious process in poorly mineralized hard tissues due to the untimely and incomplete “maturation” of them, it is beyond any doubts that scientists and practitioners involved in pediatric dentistry deal with such complications in the clinic much more often than when dealing with adults. A particularly risky group are those who develop decompensated caries, according to classification by T.F. Vinogradova. Therefore, the search for more advanced methods of diagnosis and treatment of both acute and chronic inflammation of pulp, especially with the preservation of its viability, is logical and relevant in modern dentistry. Existing methods for the biological treatment of pulpitis have their positive aspects, but possible complications up to necrosis or pulp gangrene in remote terms indicate the need for improvement both the choice of a more effective method with clear indications for its use, and the technology and material of odontotropic direction. The aim of the work was to study the results of treatment of pulpitis in experimental animals by using tricalcium silicate cement for its further application in the clinic. An experimental study was conducted on 18 animals (9-month-old male rabbits, Dutch breed) in vivarium setting to obtain information on the morphogenetic mechanisms of regeneration of living tissues and cells of dental pulp in which traumatic pulpitis was induced artificially. By the nature of odontotropic material, four groups of experimental animals were divided into: group I (control) – traumatic pulpitis was treated without special odontotropic paste, group II - treatment of pulpitis with material based on calcium hydroxide, group III - material with trioxide aggregate, group IV - material with tricalcium silicate. Every two, four, and six weeks from the moment the animals were introduced into the experiment, the damaged teeth were removed and treated in a certain way and, after special treatment, were amenable to histological examination. In the pulp tissue, the state of its main components was studied: stroma, cellular elements and blood vessels of the microvasculature. After excretion of animals from the experiment on the 2nd and 6th weeks tissues of tooth were fixed in 10% formalin. Fixed in formalin tissue has been routine proceeding after decalcification in acetic acid with making histological slides which were stained with hematoxylin and eosin (H&E), according to van Gieson, Mallory, PAS-reaction was performed. The slides were studied with the microscope “Olympus BX-41” and followed interpretation by “Olympus DP-soft version 3.2”, which was used for morphometric study. Statistical comparison was performed using Mann-Whitney test for statistical analysis. The accepted level of significance was p<0.05. Studying the state of the pulp in the phase of acute traumatic pulpitis in dynamic observation for a month and half period, at the end of the second, fourth and sixth week the possibility of a stable restoration of the viability of the pulp as well as all its components was clearly proven. If at the beginning of a morphological study, pulp injury was accompanied by clear signs of aseptic inflammation, both cellular, vascular and stromal formations, then after a month and a half there were signs of a clear restoration of pulp viability in the biological treatment of artificial pulpitis of the second, third and fourth study groups. The most significant dynamic signs of microscopic formations of the pulp were noted in animals of the forth study group treated with odontotropic paste with tricalcium silicate. The ability of this paste to complete tissue restoration in a short time period was provn. Therefore, it should be noted that artificially induced pulpitis in experimental animals is accompanied by significant breakages in the viability of the main components of pulp tissue, such as stromal fibers, microvasculature vessels and cellular elements. Filling and odontotropic materials in pastes for capping of the damaged pulp, such as calcium hydroxide, trioxide aggregate and tricalcium silicate, have full potential for restoring the viability of injured pulp, but with varying degree of effectiveness. According to histological research, biological material with tricalcium silicate is the most effective one for restoration of the pulp in a short time period.

TRATAMENTO E ANÁLISE HISTOPATOLÓGICA DE ODONTOMA COMPLEXO: RELATO DE CASO

Odontoma is a benign calcifying odontogenic tumor of unknown etiology, although local trauma, genetic factors, and chronic inflammation may be related. They are classified into compound and complex types, depending on the morphological, radiographic and histological characteristics. Clinically they hardly show signs or symptoms, and, when present, are related to delayed tooth eruption, cortical bone expansion and tooth displacement. Although radiographic exams are complementary, most cases of odontomas reported in the literature are found on routine radiographs. The diagnostic hypothesis is confirmed by histopathological examination that shows evidence of the presence of enamel, dentin, cementum and pulp tissue arranged in the form of denticles (compound) or a disorganized mass (complex). The treatment consists of surgical excision of the lesion. The aim of this article was to report a clinical case and histopathological analysis of a complex odontoma associated with an unerupted tooth, located on the left side in the posterior region of the maxilla, discovered by routine radiographic examination of a 57-year-old male patient. The treatment was surgical excision of the lesion, removal of the unerupted tooth and histopathological examination, which confirmed the diagnosis of complex odontoma. The case was followed-up clinically and radiographically for one year and showed no recurrence.

Healing of periapical lesion after root canal treatment: A case report

Most of periapical lesions usually result from microbial infection with oral microorganisms originating from the degenerated pulp tissue. These lesions are commonly painless and incidentally found on routine radiographic examinations. Treating these cases using non-surgical root canal is the fruit of the innovative techniques, tools and root medicaments as well as the tendency toward minimally invasive treatment. The healing process of the infected area is conditioned by a proper diagnosis, a treatment that follows good clinical practice under aseptic environment including cleaning, shaping and root filing. The aim of the present clinical case report was to report non-surgical healing of a periapical lesion of endodontic origin associated with maxillary left central incisor, observed over a period of 2 years.

Application of Selected Biomaterials and Stem Cells in the Regeneration of Hard Dental Tissue in Paediatric Dentistry—Based on the Current Literature

Currently, the development of the use of biomaterials and their application in medicine is causing rapid changes in the fields of regenerative dentistry. Each year, new research studies allow for the discovery of additional possibilities of dental tissue restoration. The structure and functions of teeth are complex. They consist of several diverse tissues that need to act together to ensure the tooth’s function and durability. The integrity of a tooth’s enamel, dentin, cementum, and pulp tissue allows for successful mastication. Biomaterials that are needed in dentistry must withstand excessive loading forces, be biocompatible with the hosts’ tissues, and stable in the oral cavity environment. Moreover, each tooth’s tissue, as well as aesthetic qualities in most cases, should closely resemble the natural dental tissues. This is why tissue regeneration in dentistry is such a challenge. This scientific research focuses on paediatric dentistry, its classification of caries, and the use of biomaterials in rebuilding hard dental tissues. There are several methods described in the study, including classical conservative methods such as caries infiltration or stainless-steel crowns. Several clinical cases are present, allowing a reader to better understand the described methods. Although the biomaterials mentioned in this work are artificial, there is currently ongoing research regarding clinical stem cell applications, which have a high potential for becoming one of the most common techniques of lost dental-tissue regeneration in the near future. The current state of stem cell development is mentioned, as well as the various methods of its possible application in dentistry.

Multiple Idiopathic Internal Root Resorption in an Adolescent: A Case R Multiple Idiopathic Internal Root Resorption in an Adolescent: A Case Report

Internal root resorption (IRR) refers to a slow or rapid progressive resorption process that occurs in the pulp cavity of the tooth or the dentin of the root. IRR occurs as result of odontoclast action; in many cases, the pulp tissue exhibits chronic inflammation, and odontoblasts and predentin do not appear on the dentin wall near the pulp. Exact predisposing factors have not been clearly elucidated; therefore, it is difficult to identify reliable data on the prevalence of IRR because of its scarce occurrence and pathology. Reports have indicated that IRR is more common in the primary than in the permanent teeth. This case report discusses a 17-year-old girl with multiple idiopathic internal root resorptions of anterior permanent teeth in a short period of a time and its management.