Enamel microstructure of permanent and deciduous teeth of notoungulate Toxodon: development, functional and evolutionary implications

Objective: To assess primary molars early loss in mixed dentition prevalence. Method: A study was carried out in children aged 6 to 12 years. Deciduous molar loss was considered early when it occurred before Nolla stage 6 (full formed crown) of the permanent successor or one year before its physiological exfoliation. Periapical radiographs were obtained to verify the presence of the permanent successor and the level of root formation, as well as the need for placement of fixed space maintainer lingual arch or Nance button. For the study of frequency distribution of early dental loss in relation to gender and dentition, we used the Chi-square test of 5% probability level and the non-parametric Mann-Whitney test for adequate statistical analysis. Results: Of the 315 children examined, 159 (50.47%) were male and 156 (49.52%) were female. Only 25 (7.9%) presented multiple dental losses in the posterior region, 19 in the lower arch and 6 in the upper arch. In the inferior one there was predominance of first and second deciduous molars loss. There was no difference in the association between genders and the occurrence of multiple dental losses (χ² (1) = 0.03, p>0.05). Conclusion: The prevalence of deciduous teeth premature loss was of 7.9% and the most affected teeth were the first and second molars in the lower arch. Lingual arch space holders were installed in 6 children, who will remain with it until the permanent successors erupt into the oral cavity.

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Histopathological Studies on the Healing Process of Wounds Following Pulpotomy of Deciduous Teeth : Focused on Formocresol

The Journal of the Kyushu Dental Society ◽

10.2504/kds.36.367 ◽

1982 ◽

Vol 36 (2) ◽

pp. 367-395

Author(s):

Tadashi Yokomizo

Keyword(s):

Healing Process ◽

Deciduous Teeth ◽

Histopathological Studies

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Knowledge and awareness on the stem cells from human exfoliated deciduous teeth among dental students

International Journal of Pharmaceutical Research ◽

10.31838/ijpr/2020.sp2.407 ◽

2020 ◽

Vol 12 (sp2) ◽

Keyword(s):

Stem Cells ◽

Dental Students ◽

Deciduous Teeth ◽

Human Exfoliated Deciduous Teeth

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Orthodontic Aspects on the Chronological and Dental Age in Children with Down Syndrome

Revista de Chimie ◽

10.37358/rc.18.1.6075 ◽

2018 ◽

Vol 69 (1) ◽

pp. 208-213

Author(s):

Mariana Pacurar ◽

Bogdan Dragomir ◽

Alina Silvana Szalontay ◽

Cristian Romanec

Keyword(s):

Down Syndrome ◽

Emotional Disorders ◽

Metabolic Diseases ◽

Genetic Disorder ◽

Signs And Symptoms ◽

Deciduous Teeth ◽

Healthy Children ◽

Dental Maturation ◽

Children With Down Syndrome ◽

The Family

Genetics is a key discipline in medicine, but also a clinical discipline with medical and social implications. The interest in reducing the number of genetic disorders and recognizing the risk of them repeating when a family confronts itself with a genetic anomaly becomes more and more important in the hierarchy of prophylactic emergencies. Presenting themselves as metabolic diseases (monogenic mutations) or malformations (polygenic and multifactorial heredity) because of their frequency, these disorders position themselves on an ascendant curve. They become difficult to deal with for the society, for the family and for the interested individual and cause emotional disorders. The Down syndrome is the most frequent type of genetic disorder. It is characterized by a specific set of signs and symptoms. People with Down syndrome require special medical care that, apart from the family, must include a team of doctors of various specializations and also a dentist. They are predisposed to hearing and sight disorders and thyroid problems as well. In 50% of the cases there are also anomalies of the heart, and the risk of leukaemia is 20 times higher. Some of them even develop an Alzheimer type dementia during their life. The people with Down syndrome can have an average IQ up to a moderate form of handicap. In particular, the studies on Down syndrome in dentistry are quite frequent, but they focus more on cavities, periodontal disease and hypodontia. In spite of this, the connection of Down syndrome and dental eruption is less studied. Consequently, the present study is intended to fill this missing part from the specialized literature, focusing on the relation between the Down syndrome and the chronological and dental ages in children. The health of the oral cavity is neglected in these patients, their parents focusing more on the treatment of the other systemic disorders of their children; the lack of interest is reflected in their poor oral hygiene.The trial group included 94 children with mixt dentition, aged between 6 and 12, divided as follows: 36 children with Down syndrome enrolled at the Educational Centre for Inclusive Education no. 1 of Tg. Mures and Alpha Transilvana Foundation. The chronology and the eruption sequences are subjected to certain variations and they are influenced by the presence of cavities, the premature loss or, on the contrary, the prolonged retention of deciduous teeth as well as dental anchylosis. Dental maturation is less subjected to variations, as it is a progressive, continuous and cumulative process. The presence of Down syndrome in children generates a delay in teeth eruption by 1.27 years compared to the data identified in the specialized literature and to the information obtained on the healthy children included in the study.

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Stem Cells Derived from Human Exfoliated Deciduous teeth [shed] in Neuronal Disorders: A Review

Current Stem Cell Research & Therapy ◽

10.2174/1574888x16666201221151512 ◽

2020 ◽

Vol 16 ◽

Author(s):

Minu Anoop ◽

Indrani Datta

Keyword(s):

Stem Cells ◽

Neurodegenerative Diseases ◽

Dental Pulp ◽

Therapeutic Potential ◽

Permanent Teeth ◽

Deciduous Teeth ◽

Proliferative Potential ◽

Pulp Tissue ◽

Human Exfoliated Deciduous Teeth

: Most conventional treatments for neurodegenerative diseases fail due to their focus on neuroprotection rather than neurorestoration. Stem cell‐based therapies are becoming a potential treatment option for neurodegenerative diseases as they can home in, engraft, differentiate and produce factors for CNS recovery. Stem cells derived from human dental pulp tissue differ from other sources of mesenchymal stem cells due to their embryonic neural crest origin and neurotrophic property. These include both dental pulp stem cells [DPSCs] from dental pulp tissues of human permanent teeth and stem cells from human exfoliated deciduous teeth [SHED]. SHED offer many advantages over other types of MSCs such as good proliferative potential, minimal invasive procurement, neuronal differentiation and neurotrophic capacity, and negligible ethical concerns. The therapeutic potential of SHED is attributed to the paracrine action of extracellularly released secreted factors, specifically the secretome, of which exosomes is a key component. SHED and its conditioned media can be effective in neurodegeneration through multiple mechanisms, including cell replacement, paracrine effects, angiogenesis, synaptogenesis, immunomodulation, and apoptosis inhibition, and SHED exosomes offer an ideal refined bed-to-bench formulation in neurodegenerative disorders. However, in spite of these advantages, there are still some limitations of SHED exosome therapy, such as the effectiveness of long-term storage of SHED and their exosomes, the development of a robust GMP-grade manufacturing protocol, optimization of the route of administration, and evaluation of the efficacy and safety in humans. In this review, we have addressed the isolation, collection and properties of SHED along with its therapeutic potential on in vitro and in vivo neuronal disorder models as evident from the published literature.

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Comparative evaluation of osteogenic differentiation potential of stem cells derived from dental pulp and exfoliated deciduous teeth cultured over granular hydroxyapatite based scaffold

BMC Oral Health ◽

10.1186/s12903-021-01621-0 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Manal Nabil Hagar ◽

Farinawati Yazid ◽

Nur Atmaliya Luchman ◽

Shahrul Hisham Zainal Ariffin ◽

Rohaya Megat Abdul Wahab

Keyword(s):

Stem Cells ◽

Osteogenic Differentiation ◽

Dental Pulp ◽

3D Culture ◽

Permanent Teeth ◽

Deciduous Teeth ◽

Osteogenic Potential ◽

Control Group ◽

Rt Pcr ◽

Differentiation Potential

Abstract Background Mesenchymal stem cells isolated from the dental pulp of primary and permanent teeth can be differentiated into different cell types including osteoblasts. This study was conducted to compare the morphology and osteogenic potential of stem cells from exfoliated deciduous teeth (SHED) and dental pulp stem cells (DPSC) in granular hydroxyapatite scaffold (gHA). Preosteoblast cells (MC3T3-E1) were used as a control group. Methodology The expression of stemness markers for DPSC and SHED was evaluated using reverse transcriptase-polymerase chain reaction (RT-PCR). Alkaline phosphatase assay was used to compare the osteoblastic differentiation of these cells (2D culture). Then, cells were seeded on the scaffold and incubated for 21 days. Morphology assessment using field emission scanning electron microscopy (FESEM) was done while osteogenic differentiation was detected using ALP assay (3D culture). Results The morphology of cells was mononucleated, fibroblast-like shaped cells with extended cytoplasmic projection. In RT-PCR study, DPSC and SHED expressed GAPDH, CD73, CD105, and CD146 while negatively expressed CD11b, CD34 and CD45. FESEM results showed that by day 21, dental stem cells have a round like morphology which is the morphology of osteoblast as compared to day 7. The osteogenic potential using ALP assay was significantly increased (p < 0.01) in SHED as compared to DPSC and MC3T3-E1 in 2D and 3D cultures. Conclusion gHA scaffold is an optimal scaffold as it induced osteogenesis in vitro. Besides, SHED had the highest osteogenic potential making them a preferred candidate for tissue engineering in comparison with DPSC.

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A Comparative Evaluation of Nanohydroxyapatite-Enriched Hydrogen Peroxide Home Bleaching System on Color, Hardness and Microstructure of Dental Enamel

Materials ◽

10.3390/ma14113072 ◽

2021 ◽

Vol 14 (11) ◽

pp. 3072

Author(s):

Riccardo Monterubbianesi ◽

Vincenzo Tosco ◽

Tiziano Bellezze ◽

Giampaolo Giuliani ◽

Mutlu Özcan ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Particle Diameter ◽

Dental Enamel ◽

Sem Analysis ◽

Control Group ◽

Average Particle ◽

Color Analysis ◽

Enamel Microstructure ◽

Prismatic Structure ◽

20 Nm

This study aimed to evaluate two hydrogen peroxide (HP)-based at-home bleaching systems in order to analyze whether nano-hydroxyapatite (nHA) addition may represent a reliable and safe solution for tooth whitening without altering dental microstructure and hardness. Human third molars (N = 15) were treated with two bleaching agents, one containing 6%HP (6HP) and the other 6% HP nHA-enriched (6HP-nHA) with average particle diameter ranging from 5–20 nm. Their effects on enamel were assessed using a spectrophotometer, Vickers microhardness (VMH) test and Scanning Electron Microscopy (SEM), comparing the treated groups with the non-treated control group (CTR). Color analysis revealed improvement in whiteness in both groups compared to CTR. VMH test results showed no differences among the groups. SEM analysis highlighted no evident changes in the enamel microstructure of tested groups compared to CTR. At high magnification, in 6HP group, a slight increase in irregularities of enamel surface morphology was observed, while 6HP-nHA group displayed removal of the aprismatic layer but preservation of the intact prismatic structure. These results suggest that the 6HP-nHA agent may be recommended to provide reliable whitening treatment, without damaging the enamel micromorphology and hardness.

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