Deciphering the Epigenetic Code of Stem Cells Derived From Dental Tissues

Stem cells derived from dental tissues (DSCs) exhibit multipotent regenerative potential in pioneering tissue engineering regimens. The multipotency of DSCs is critically regulated by an intricate range of factors, of which the epigenetic influence is considered vital. To gain a better understanding of how epigenetic alterations are involved in the DSC fate determination, the present review overviews the current knowledge relating to DSC epigenetic modifications, paying special attention to the landscape of epigenetic modifying agents as well as the related signaling pathways in DSC regulation. In addition, insights into the future opportunities of epigenetic targeted therapies mediated by DSCs are discussed to hold promise for the novel therapeutic interventions in future translational medicine.

Automatic exposure compensation in intraoral digital radiography: effect on the gray values of dental tissues

Background This study aimed to investigate the effect of automatic exposure compensation (AEC) of intraoral radiographic systems on the gray values of dental tissues in images acquired with or without high-density material in the exposed region using different exposure times and kilovoltages. The influence of the distance of the high-density material was also investigated. Methods Radiographs from the molar region of two mandibles were obtained using the RVG 6100 and the Express systems, operating at 60 and 70 kV and 0.06, 0.10, and 0.16 s. Subsequently, a titanium implant was inserted in the premolar’s socket and other images were acquired. Using the ImageJ software, two regions of interest were determined on the enamel, coronary dentine, root dentine, and pulp of the first and second molars to obtain their gray values. Results In the RVG 6100, the implant did not affect the gray values (p > 0.05); the increase in kV decreased it in all tissues (p < 0.05), and the exposure time affected only the root dentine and pulp. In the Express, only enamel and coronary dentine values changed (p < 0.05), decreasing with the implant presence and/or with the increase in exposure factors. The distance of the implant did not affect the results (p > 0.05). Conclusions AEC’s performance varies between the radiographic systems. Its effect on the gray values depends not only on the presence or absence of high-density material but also on the kV and exposure time used.

Mechanisms and substances involved in clastic activity of root resorptions – literature review

Aim: to research through literature review, the mechanisms involved in the establishment of root resorptions. Mediators such as interleukins, prostaglandins, nitric oxide and systemic calcium available were studied in this review. Methods: On line searches were accomplished by scrutinizing the database available from PUBMED Central, BVS/BIREME. Web of Science, Science Direct, Periodic Portal from CAPES, as well as The Cochrane Library and PROSPERO were also used. The inclusion criteria were articles that described osteoclastic activity involving the hard dental tissues (cement, dentin and enamel). The search acquired 35 articles and excluded other 30. The articles acquired ranged from 1976 up to 2017. Results: the results showed that the combination of the immunologic mediators researched above will be the determinant factors on the establishment of root resorptions. Conclusions: Prostaglandins, Interleukins as well as the systemic calcium available are some of the most important factors for the establishment of root resorptions. Their final outcome, however, depends directly on the quality of injury inflicted over the group of teeth, or single tooth, involved.

Effects of cystic fibrosis on the oral cavity

Cystic fibrosis is a complex, lethal, multi-system autosomal recessive disease resulting from mutations on chromosome 7 that cause dysfunction of an ion channel located on epithelial surfaces. Pulmonary disease is the leading cause of morbidity and mortality in CF. The specific dental manifestations of the disease may result from the condition itself or from complications of treatment. This study presents the dental problems observed in patients with cystic fibrosis and reported in the literature. Particular attention was paid to dental caries, disturbances in the mineralization of hard dental tissues, gingivitis and changes in the content and properties of saliva.

Vibrational Imaging Techniques for the Characterization of Hard Dental Tissues: From Bench-Top to Chair-Side

[...]

Large atypical odontome in the ramus of mandible: A rare case report

Compound odontoma is considered to be a developmental anomalies of the dental tissues or a hamartomatous lesion rather than a true odontogenic tumour. It has an unknown etiology. Odontomas are further subdivided into compound and complex types depending on the extent of morpho-differentiation or on the resemblance to normal teeth. Since, these lesions are asymptomatic, they are usually detected in routine radiographs only. Early diagnosis, prompt clinical decision making followed by a proper treatment at the right time, results in a favorable prognosis. The present report describes a large atypical radiopaque mass located in the ramus of mandible. After the lesion was surgically removed under local anesthesia, histopathological examination confirmed the diagnosis of compound odontoma. The results achieved indicate that the early diagnosis of odontomas allows the adoption of a less complex and expensive treatment and ensures better prognosis.

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.

COMPUTER TECHNOLOGIES FOR DETERMINING INDEX ASSESSMENT OF THE DESTRUCTION OF DENTAL HARD TISSUES

The aim of the study was to compare the obtained data of hard dental tissues destruction indices with the corresponding indications for the choice of the method of treatment by means of mathematical analysis. Materials & methods. 120 patients aged 20 to 55 were examined and 358 teeth hard tissue defects were identified in them. The data of indices was obtained and compared with the indications for orthopedic treatment according two indices in the same clinical situation. Results. The study showed that the indices had different meanings and different indications for treatment in the same situations. Such discrepancies in indications for treatment indicate the subjective data of one of the indices, which does not take into account the depth of destruction and the volume of the remaining natural tissue of the teeth. Comparison of these indices showed different figures in the same clinical situation, identifying corresponding incorrect indications for the choice of the design of the first investigated index, as well as more accurate data of the proposed index. Conclusion. The index assessment of hard dental tissues destruction serves as the main guideline for the dentist when choosing a method for tooth restoration, and can be calculated using photographs, scans and computer software.

Dental-Plaque Decontamination around Dental Brackets Using Antimicrobial Photodynamic Therapy: An In Vitro Study

Background: In orthodontic therapy, the enamel around brackets is very susceptible to bacterial-plaque retention, which represents a risk factor for dental tissues. The aim of this study was to evaluate the effect of methylene blue and a chlorophyllin–phycocyanin mixture, used with and without light activation, in contrast with a 2% chlorhexidine solution, on Streptococcus mutans colonies. Methods: Twenty caries-free human extracted teeth were randomized into five groups. A Streptococcus mutans suspension was inoculated on teeth in groups B, C, D, and E (A was the positive-control group). Bacterial colonies from groups C, D, and E (B was the negative-control group) were subjected to photosensitizers and 2% chlorhexidine solution. For groups C and D, a combined therapy consisting of photosensitizer and light activation was performed. The Streptococcus mutans colonies were counted, and smears were examined with an optical microscope. Two methods of statistical analysis, unidirectional analysis of variance and the Tukey–Kramer test, were used to evaluate the results. Results: A statistically significant reduction in bacterial colonies was detected after the combined therapy was applied for groups C and D, but the most marked bacterial reduction was observed for group D, where a laser-activated chlorophyll–phycocyanin mixture was used. Conclusions: Photodynamic therapy in combination with methylene blue or chlorophyllin–phycocyanin mixture sensitizers induces a statistically significant decrease in the number of bacterial colonies.

The study of the calcium and phosphorus metabolism impact on the development of demineralized enamel areas in adolescents

Relevance. The article presents the current data on the impact of calcium and phosphorus metabolism on the development of demineralized enamel areas in adolescents. The level of vitamin D3, osteocalcin, bone alkaline phosphatase isoenzyme and parathyroid hormone (PTH) in mixed saliva appeared to reflect the risk of the cariogenic situation in the oral cavity and the risk of enamel demineralization development, which are relevant in pediatric dentistry. Purpose – to reveal the relationship between the localized enamel demineralization and the calcium and phosphorus metabolism in teenagers.Materials and methods. In 45 adolescents, the study examined the vulnerability of hard dental tissues, including initial lesions and the mixed saliva mineral metabolism in teenagers. We formed the following groups to study the caries intensity level. Group 1 consisted of 12 adolescents with a DMF index of 3.8. 11 adolescents comprised group 2 and 11 adolescents – group 3 with DMF indices of 4.9 and 6.8, respectively; group 4 contained adolescents without caries.Results. The analysis of caries intensity and permanent enamel demineralization areas in adolescents and the main markers of mixed saliva mineralization revealed a correlation between the activity of the initial carious lesions and the calcium and phosphate metabolism.Conclusions. Evaluating the principal markers of calcium and phosphorus metabolism is relevant for the risk assessment of the cariogenic situation or enamel demineralization development in adolescents and preventive treatment planning.