Innovative Approaches to Regenerate Enamel and Dentin

The process of tooth mineralization and the role of molecular control of cellular behavior during embryonic tooth development have attracted much attention the last few years. The knowledge gained from the research in these fields has improved the general understanding about the formation of dental tissues and the entire tooth and set the basis for teeth regeneration. Tissue engineering using scaffold and cell aggregate methods has been considered to produce bioengineered dental tissues, while dental stem/progenitor cells, which can differentiate into dental cell lineages, have been also introduced into the field of tooth mineralization and regeneration. Some of the main strategies for making enamel, dentin, and complex tooth-like structures are presented in this paper. However, there are still significant barriers that obstruct such strategies to move into the regular clinic practice, and these should be overcome in order to have the regenerative dentistry as the important mean that can treat the consequences of tooth-related diseases

Systems Biology Approaches and Precision Oral Health: A Circadian Clock Perspective

A vast majority of the pathophysiological and metabolic processes in humans are temporally controlled by a master circadian clock located centrally in the hypothalamic suprachiasmatic nucleus of the brain, as well as by specialized peripheral oscillators located in other body tissues. This circadian clock system generates a rhythmical diurnal transcriptional-translational cycle in clock genes and protein expression and activities regulating numerous downstream target genes. Clock genes as key regulators of physiological function and dysfunction of the circadian clock have been linked to various diseases and multiple morbidities. Emerging omics technologies permits largescale multi-dimensional investigations of the molecular landscape of a given disease and the comprehensive characterization of its underlying cellular components (e.g., proteins, genes, lipids, metabolites), their mechanism of actions, functional networks and regulatory systems. Ultimately, they can be used to better understand disease and interpatient heterogeneity, individual profile, identify personalized targetable key molecules and pathways, discover novel biomarkers and genetic alterations, which collectively can allow for a better patient stratification into clinically relevant subgroups to improve disease prediction and prevention, early diagnostic, clinical outcomes, therapeutic benefits, patient's quality of life and survival. The use of “omics” technologies has allowed for recent breakthroughs in several scientific domains, including in the field of circadian clock biology. Although studies have explored the role of clock genes using circadiOmics (which integrates circadian omics, such as genomics, transcriptomics, proteomics and metabolomics) in human disease, no such studies have investigated the implications of circadian disruption in oral, head and neck pathologies using multi-omics approaches and linking the omics data to patient-specific circadian profiles. There is a burgeoning body of evidence that circadian clock controls the development and homeostasis of oral and maxillofacial structures, such as salivary glands, teeth and oral epithelium. Hence, in the current era of precision medicine and dentistry and patient-centered health care, it is becoming evident that a multi-omics approach is needed to improve our understanding of the role of circadian clock-controlled key players in the regulation of head and neck pathologies. This review discusses current knowledge on the role of the circadian clock and the contribution of omics-based approaches toward a novel precision health era for diagnosing and treating head and neck pathologies, with an emphasis on oral, head and neck cancer and Sjögren's syndrome

Extracellular Matrix Membrane Induces Cementoblastic/Osteogenic Properties of Human Periodontal Ligament Stem Cells

Objective: Periodontitis affects nearly 90% of adults over the age of 70, resulting to periodontal tissue infection, destruction, and ultimately tooth loss. Guided tissue regeneration (GTR) is a method widely used to treat severe periodontal disease, and involves placement of an occlusive barrier to facilitate regeneration of the damaged area by periodontal ligament stem cells (PDLSCs). In this study, we evaluate natural extracellular matrix (ECM) as a scaffold material to provide a suitable microenvironment to support the proliferation, differentiation, and tissue-regenerating properties of PDLSCs.Design: The viability, proliferation, apoptosis, and migration of PDLSCs cultured on ECM membrane, that was isolated from porcine urinary bladders, were compared with those cultured on type I collagen membrane, a commonly used scaffold in GTR. To evaluate the effects of ECM vs. type I collagen on the tissue-regenerating properties of PDLSCs, the bio-attachment and cementoblastic/osteogenic differentiation of PDLSCs were evaluated.Results: Incubation of PDLSCs with ECM resulted in increased viability, proliferation, and reduced apoptosis, compared with type I collagen treated PDLSCs. Co-culture with ECM membrane also increased the migration and bio-attachment of PDLSCs. Incubation of PDLSCs with ECM membrane increased expression of the cementoblastic/osteogenic differentiation markers BSP, RUNX2, ALP, OPN, OCN, and periostin.Conclusion: ECM membrane enhances the proliferation and regenerative properties of PDLSCs, indicating that ECM membrane can serve as a suitable scaffold in the application of GTR to treat periodontal disease

Orai1 expression pattern in tooth and craniofacial ectodermal tissues and potential functions during ameloblast differentiation

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113781/1/dvdy24307.pd

LES DETERMINANTS MOLECULAIRES DES AGENESIES DENTAIRES

PARIS7-Odontologie (751062104) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Self-Crosslinkable Oxidized Alginate-Carboxymethyl Chitosan Hydrogels as an Injectable Cell Carrier for In Vitro Dental Enamel Regeneration

Injectable hydrogels, as carriers, offer great potential to incorporate cells or growth factors for dental tissue regeneration. Notably, the development of injectable hydrogels with appropriate structures and properties has been a challenging task, leaving much to be desired in terms of cytocompatibility, antibacterial and self-healing properties, as well as the ability to support dental stem cell functions. This paper presents our study on the development of a novel self-cross-linkable hydrogel composed of oxidized alginate and carboxymethyl chitosan and its characterization as a cell carrier for dental enamel regeneration in vitro. Oxidized alginate was synthesized with 60% theoretical oxidation degree using periodate oxidation and characterized by Fourier Transform Infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and Ultraviolet-visible absorption spectroscopy. Then, hydrogels were prepared at three varying weight ratios of oxidized alginate to carboxymethyl chitosan (4:1, 3:1, and 2:1) through Schiff base reactions, which was confirmed by Fourier Transform Infrared spectroscopy. The hydrogels were characterized in terms of gelation time, swelling ratio, structure, injectability, self-healing, antibacterial properties, and in vitro characterization for enamel regeneration. The results demonstrated that, among the three hydrogels examined, the one with the highest ratio of oxidized alginate (i.e., 4:1) had the fastest gelation time and the lowest swelling ability, and that all hydrogels were formed with highly porous structures and were able to be injected through a 20-gauge needle without clogging. The injected hydrogels could be rapidly reformed with the self-healing property. The hydrogels also showed antibacterial properties against two cariogenic bacteria: Streptococcus mutans and Streptococcus sobrinus. For in vitro enamel regeneration, a dental epithelial cell line, HAT-7, was examined, demonstrating a high cell viability in the hydrogels during injection. Furthermore, HAT-7 cells encapsulated in the hydrogels showed alkaline phosphatase production and mineral deposition, as well as maintaining their round morphology, after 14 days of in vitro culture. Taken together, this study has provided evidence that the oxidized alginate-carboxymethyl chitosan hydrogels could be used as an injectable cell carrier for dental enamel tissue engineering applications

Equity-diversity-inclusion (EDI)-related strategies used by dental schools during the admission/selection process: a narrative review

Abstract Introduction Decades of evidence have demonstrated a lack of workforce diversity and sustaining disparities in academic dentistry and professional practice. Underrepresented minority students may face challenges and implicit bias during the dental schools‘ admission/selection process. This review collected papers from different countries to summarize the Equity-Diversity-Inclusion (EDI)-related strategies that dental schools worldwide have used in their admissions process to increase diversity. Methods A comprehensive search using MEDLINE (via PubMed), ERIC, Cochrane Reviews, Cochrane Trials, American Psychological Association Psyc Info (EBSCO) and Scopus was done between January and March-2023. All types of articles-designs were included, except comments and editorials, and all articles selected were in English. Two independent investigators screened the articles. Extracted data were general characteristics, study objectives, and EDI-related strategies. Results Sixteen publications were used to construct this manuscript. The year with the greatest number of publications was 2022. Type of studies were case studies/critical reviews (50%), cross-sectional (including survey and secondary data analysis) (n = 5, 31.25%), qualitative methods of analysis (n = 2, 12.5%), and retrospective/secondary data collection (n = 1, 6.25%). The strategies described in the articles were related to (1) considering the intersectionality of diversity, (2) using noncognitive indicators during the school admissions process to construct a holistic selection process, (3) diversifying, professionalizing, and providing training to admissions persons who had leadership roles with the support from the dental school and the university, and (4) allocating financial investments and analyzing current policies and procedures regarding EDI. Conclusions This review aggregated interesting findings, such as: some schools are considering the intersectionality of diversity as a way to include underrepresented minorities and to diversify the students-body. The recent growth in publications on EDI during dental admission/selection process might indicate a positive movement in this field

Development of a Nutrition Questionnaire for Dental Caries Risk Factors

Background: Few existing tools quickly identify dietary behaviours related to dental caries. The objectives of this study were to (i) create a patient-generated questionnaire identifying these dietary behaviours, (ii) capture information on these dietary behaviours in two specific populations via questionnaire pilot testing and (iii) determine questionnaire test-retest reliability. Methods: After development, the questionnaire was reviewed by an expert panel. Cognitive interviewing was conducted, followed by pilot testing in a general university campus population (n = 80) and a university dental clinic (n = 10). Retesting was done with the general campus group (n = 53). Results: Most participants reported never receiving dietary advice from professionals regarding caries. Sugary foods were most often consumed as snacks in the evening or afternoon, then breakfast. In total, 41.3% of campus participants consumed high risk items at least a few times per week or more often. Weekly or more frequent consumption of “other” sugary drinks (e.g., iced tea) was common. In total, 77.6% of questionnaire items had a kappa value representing moderate agreement or greater. Conclusions: Dietary behaviours related to caries were common in this pilot study. Given the high prevalence of caries and low occurrence of prior dietary advice for the same, increased preventive efforts may be warranted

Editorial: Alveolar Bone: A Pivotal Role in Periodontal Disease Pathobiology and Treatment

International audienc