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Dental Clinics of North America Oct 2017This article provides a brief review of recent investigations concerning the structure and properties of the tooth. The last decade has brought a greater emphasis on the... (Review)
Review
This article provides a brief review of recent investigations concerning the structure and properties of the tooth. The last decade has brought a greater emphasis on the durability of the tooth, an improved understanding of the fatigue and fracture behavior of the principal tissues, and their importance to tooth failures. The primary contributions to tooth durability are discussed, including the process of placing a restoration, the impact of aging, and challenges posed by the oral environment. The significance of these findings to the dental community and their importance to the pursuit of lifelong oral health are highlighted.
Topics: Aging; Dental Enamel; Dentin; Humans; Tooth
PubMed: 28886762
DOI: 10.1016/j.cden.2017.05.001 -
International Journal of Molecular... Jun 2020Tooth enamel is the outer covering of tooth crowns, the hardest material in the mammalian body, yet fracture resistant. The extremely high content of 95 wt% calcium... (Review)
Review
Tooth enamel is the outer covering of tooth crowns, the hardest material in the mammalian body, yet fracture resistant. The extremely high content of 95 wt% calcium phosphate in healthy adult teeth is achieved through mineralization of a proteinaceous matrix that changes in abundance and composition. Enamel-specific proteins and proteases are known to be critical for proper enamel formation. Recent proteomics analyses revealed many other proteins with their roles in enamel formation yet to be unraveled. Although the exact protein composition of healthy tooth enamel is still unknown, it is apparent that compromised enamel deviates in amount and composition of its organic material. Why these differences affect both the mineralization process before tooth eruption and the properties of erupted teeth will become apparent as proteomics protocols are adjusted to the variability between species, tooth size, sample size and ephemeral organic content of forming teeth. This review summarizes the current knowledge and published proteomics data of healthy and diseased tooth enamel, including advancements in forensic applications and disease models in animals. A summary and discussion of the status quo highlights how recent proteomics findings advance our understating of the complexity and temporal changes of extracellular matrix composition during tooth enamel formation.
Topics: Animals; Dental Enamel; Dental Enamel Proteins; Extracellular Matrix; Humans; Proteome; Tooth
PubMed: 32585904
DOI: 10.3390/ijms21124458 -
Physiological Reviews Jul 2017Dental enamel is the hardest and most mineralized tissue in extinct and extant vertebrate species and provides maximum durability that allows teeth to function as... (Review)
Review
Dental enamel is the hardest and most mineralized tissue in extinct and extant vertebrate species and provides maximum durability that allows teeth to function as weapons and/or tools as well as for food processing. Enamel development and mineralization is an intricate process tightly regulated by cells of the enamel organ called ameloblasts. These heavily polarized cells form a monolayer around the developing enamel tissue and move as a single forming front in specified directions as they lay down a proteinaceous matrix that serves as a template for crystal growth. Ameloblasts maintain intercellular connections creating a semi-permeable barrier that at one end (basal/proximal) receives nutrients and ions from blood vessels, and at the opposite end (secretory/apical/distal) forms extracellular crystals within specified pH conditions. In this unique environment, ameloblasts orchestrate crystal growth via multiple cellular activities including modulating the transport of minerals and ions, pH regulation, proteolysis, and endocytosis. In many vertebrates, the bulk of the enamel tissue volume is first formed and subsequently mineralized by these same cells as they retransform their morphology and function. Cell death by apoptosis and regression are the fates of many ameloblasts following enamel maturation, and what cells remain of the enamel organ are shed during tooth eruption, or are incorporated into the tooth's epithelial attachment to the oral gingiva. In this review, we examine key aspects of dental enamel formation, from its developmental genesis to the ever-increasing wealth of data on the mechanisms mediating ionic transport, as well as the clinical outcomes resulting from abnormal ameloblast function.
Topics: Ameloblasts; Amelogenesis; Animals; Dental Enamel; Dental Enamel Proteins; Evolution, Molecular; Genetic Predisposition to Disease; Humans; Oral Health; Phenotype; Species Specificity; Tooth Abnormalities; Tooth Diseases
PubMed: 28468833
DOI: 10.1152/physrev.00030.2016 -
International Journal of Molecular... Feb 2020Sonic hedgehog (Shh) is a secreted protein with important roles in mammalian embryogenesis. During tooth development, Shh is primarily expressed in the dental... (Review)
Review
Sonic hedgehog (Shh) is a secreted protein with important roles in mammalian embryogenesis. During tooth development, Shh is primarily expressed in the dental epithelium, from initiation to the root formation stages. A number of studies have analyzed the function of Shh signaling at different stages of tooth development and have revealed that Shh signaling regulates the formation of various tooth components, including enamel, dentin, cementum, and other soft tissues. In addition, dental mesenchymal cells positive for Gli1, a downstream transcription factor of Shh signaling, have been found to have stem cell properties, including multipotency and the ability to self-renew. Indeed, Gli1-positive cells in mature teeth appear to contribute to the regeneration of dental pulp and periodontal tissues. In this review, we provide an overview of recent advances related to the role of Shh signaling in tooth development, as well as the contribution of this pathway to tooth homeostasis and regeneration.
Topics: Animals; Dental Enamel; Dental Pulp; Epithelium; Hedgehog Proteins; Homeostasis; Humans; Mesenchymal Stem Cells; Odontogenesis; Signal Transduction; Tooth; Tooth Root; Zinc Finger Protein GLI1
PubMed: 32111038
DOI: 10.3390/ijms21051587 -
International Journal of Oral Science Jan 2019Tooth enamel is a complex mineralized tissue consisting of long and parallel apatite crystals configured into decussating enamel rods. In recent years, multiple... (Review)
Review
Tooth enamel is a complex mineralized tissue consisting of long and parallel apatite crystals configured into decussating enamel rods. In recent years, multiple approaches have been introduced to generate or regenerate this highly attractive biomaterial characterized by great mechanical strength paired with relative resilience and tissue compatibility. In the present review, we discuss five pathways toward enamel tissue engineering, (i) enamel synthesis using physico-chemical means, (ii) protein matrix-guided enamel crystal growth, (iii) enamel surface remineralization, (iv) cell-based enamel engineering, and (v) biological enamel regeneration based on de novo induction of tooth morphogenesis. So far, physical synthesis approaches using extreme environmental conditions such as pH, heat and pressure have resulted in the formation of enamel-like crystal assemblies. Biochemical methods relying on enamel proteins as templating matrices have aided the growth of elongated calcium phosphate crystals. To illustrate the validity of this biochemical approach we have successfully grown enamel-like apatite crystals organized into decussating enamel rods using an organic enamel protein matrix. Other studies reviewed here have employed amelogenin-derived peptides or self-assembling dendrimers to re-mineralize mineral-depleted white lesions on tooth surfaces. So far, cell-based enamel tissue engineering has been hampered by the limitations of presently existing ameloblast cell lines. Going forward, these limitations may be overcome by new cell culture technologies. Finally, whole-tooth regeneration through reactivation of the signaling pathways triggered during natural enamel development represents a biological avenue toward faithful enamel regeneration. In the present review we have summarized the state of the art in enamel tissue engineering and provided novel insights into future opportunities to regenerate this arguably most fascinating of all dental tissues.
Topics: Acid Etching, Dental; Amelogenin; Biomimetics; Dental Enamel; Dental Enamel Proteins; Dentistry; Tissue Engineering; Tooth Remineralization
PubMed: 30610185
DOI: 10.1038/s41368-018-0038-6 -
F1000Research 2019Tooth whitening usually includes the direct use of gels containing carbamide or hydrogen peroxide on the tooth enamel surface through a wide variety of products...
Tooth whitening usually includes the direct use of gels containing carbamide or hydrogen peroxide on the tooth enamel surface through a wide variety of products formulas. A generally new advancement in whitening of teeth uses the significant importance of the tooth color shift from yellow to blue in delivering a general enhancement in the observation of tooth whiteness. The aim of the current work was to measure the tooth whitening effects, surface roughness and enamel morphology of six different types of blue covarine-containing and blue covarine-free toothpastes using in vitro models. A total of 70 sound extracted human premolars were randomly and equally divided into seven groups, and each subjected to tooth brushing using different toothpastes. Tooth color and enamel surface roughness were measured before and after the brushing procedure using a white light interferometer, and scanning electron microscopy (SEM) was used to assess tooth surface after the procedure. Toothpaste containing blue covarine resulted in the greatest improvement in tooth color amongst all groups as well as a statistically significant color difference when compared to blue covarine-free toothpaste. Furthermore, blue covarine-containing toothpaste resulted in fewer morphological changes to the enamel surface. This was confirmed with SEM images that showed smooth enamel surfaces with fine scratches. The results from the present study show that blue covarine containing toothpastes are reliable, effective in tooth whitening and produce less surface abrasion when compared to blue covarine-free toothpastes.
Topics: Coloring Agents; Dental Enamel; Humans; Tooth; Tooth Bleaching; Toothpastes
PubMed: 31839926
DOI: 10.12688/f1000research.20811.1 -
Journal of Nanobiotechnology Jan 2019Dental caries is a recognized worldwide public health problem. Despite being one of the most effective strategies against dental caries, the excessive use of fluorine... (Comparative Study)
Comparative Study
BACKGROUND
Dental caries is a recognized worldwide public health problem. Despite being one of the most effective strategies against dental caries, the excessive use of fluorine may result in a potential risk of developing dental fluorosis especially in children under age of six. The purpose of this work is to analyze a fluorine-free toothpaste containing Biomimetic Hydroxyapatite to assess enamel re-mineralizing and repairing properties.
RESULTS
The study was performed in vitro and in vivo, comparing the hydroxyapatite toothpaste with two others toothpaste containing different fluorine concentrations. The coating effect of the micro-structured Hydroxyapatite nanoparticles reintegrates the enamel with a biomimetic film reproducing the structure and the morphology of the biologic Hydroxyapatite of the enamel. As demonstrated, the coating is due to the deposit of a new layer of apatite, which presents fewer particles than the natural enamel, not based on the chemical-physical changes occurring in fluorinated toothpastes. Moreover, it shows resistance to brushing as a consequence of chemical bonds between the synthetic and natural crystals of the enamel.
CONCLUSIONS
The use of Biomimetic Hydroxyapatite toothpastes has proven to be a valuable prevention measure against dental caries in primary dentition since it prevents the risk of fluorosis.
Topics: Biomimetics; Child; Coated Materials, Biocompatible; Dental Caries; Dental Enamel; Durapatite; Fluorides; Humans; Streptococcus mutans; Tooth Remineralization; Tooth, Deciduous; Toothpastes
PubMed: 30683113
DOI: 10.1186/s12951-019-0454-6 -
Calcified Tissue International Nov 2017Amelogenesis (tooth enamel formation) is a biomineralization process consisting primarily of two stages (secretory stage and maturation stage) with unique features.... (Review)
Review
Amelogenesis (tooth enamel formation) is a biomineralization process consisting primarily of two stages (secretory stage and maturation stage) with unique features. During the secretory stage, the inner epithelium of the enamel organ (i.e., the ameloblast cells) synthesizes and secretes enamel matrix proteins (EMPs) into the enamel space. The protein-rich enamel matrix forms a highly organized architecture in a pH-neutral microenvironment. As amelogenesis transitions to maturation stage, EMPs are degraded and internalized by ameloblasts through endosomal-lysosomal pathways. Enamel crystallite formation is initiated early in the secretory stage, however, during maturation stage the more rapid deposition of calcium and phosphate into the enamel space results in a rapid expansion of crystallite length and mineral volume. During maturation-stage amelogenesis, the pH value of enamel varies considerably from slightly above neutral to acidic. Extracellular acid-base balance during enamel maturation is tightly controlled by ameloblast-mediated regulatory networks, which include significant synthesis and movement of bicarbonate ions from both the enamel papillary layer cells and ameloblasts. In this review we summarize the carbonic anhydrases and the carbonate transporters/exchangers involved in pH regulation in maturation-stage amelogenesis. Proteins that have been shown to be instrumental in this process include CA2, CA6, CFTR, AE2, NBCe1, SLC26A1/SAT1, SLC26A3/DRA, SLC26A4/PDS, SLC26A6/PAT1, and SLC26A7/SUT2. In addition, we discuss the association of miRNA regulation with bicarbonate transport in tooth enamel formation.
Topics: Amelogenesis; Animals; Anion Transport Proteins; Bicarbonates; Biological Transport; Carbonic Anhydrases; Chloride-Bicarbonate Antiporters; Cystic Fibrosis Transmembrane Conductance Regulator; Dental Enamel; Humans; MicroRNAs; Sodium-Bicarbonate Symporters
PubMed: 28795233
DOI: 10.1007/s00223-017-0311-2 -
Medical Principles and Practice :... 2015A review is presented of the mechanical damage suffered by tooth crowns. This has been the subject of much recent research, resulting in a need to revise some of the... (Review)
Review
A review is presented of the mechanical damage suffered by tooth crowns. This has been the subject of much recent research, resulting in a need to revise some of the thinking about the mechanisms involved. Damage is classified here by scale into macro-, meso- and microfracture. The focus is on the outer enamel coat because this is the contact tissue and where most fractures start. Enamel properties appear to be tailored to maximize hardness, but also to prevent fracture. The latter is achieved by the deployment of developmental flaws called enamel tufts. Macrofractures usually appear to initiate as extensions of tufts on the undersurface of the enamel adjacent to the enamel-dentine junction and extend from there into the enamel. Cracks that pass from the tooth surface tend to be deflected by an enamel region of high toughness; if they find the surface again, a chip (mesofracture) is produced. The real protection of the enamel-dentine junction here is the layer of decussating inner enamel. Finally, a novel analysis of mechanical wear (microfracture) suggests that the local toughness of the enamel is very important to its ability to resist tissue loss. Enamel and dentine have contrasting behaviours. Seen on a large scale, dentine is isotropic (behaving similarly in all directions) while enamel is anisotropic, but vice versa on a very small scale. These patterns have implications for anyone studying the fracture behaviour of teeth.
Topics: Bicuspid; Biomechanical Phenomena; Cuspid; Dental Enamel; Dental Stress Analysis; Fractures, Stress; Humans; Incisor; Molar; Stress, Mechanical; Surface Properties; Tooth; Tooth Fractures; Tooth Wear
PubMed: 25427777
DOI: 10.1159/000367976 -
Romanian Journal of Morphology and... 2022The paper aims to study the impact of ozone (O3) treatment on the microstructural changes of the tooth enamel after the treatment at different time intervals. The...
The paper aims to study the impact of ozone (O3) treatment on the microstructural changes of the tooth enamel after the treatment at different time intervals. The ozonation was performed with gaseous O3 produced by HealOzone X4, the demineralization level was measured with the DiagnoDent Pen 2190 device, and the microstructure changes of enamel surface were observed using scanning electron microscopy (SEM) analysis. The results showed the exposure to O3 for 40-50 seconds enhanced enamel micro-hardness and ensures a rate of remineralization between 96.82-97.38%. In conclusion, in search of new minimally invasive solutions in the treatment of caries and to offer antimicrobial support of the oral cavity, the use of O3 as an alternative therapy to classical solutions may be a viable solution in dentistry.
Topics: Humans; Tooth Demineralization; Ozone; Tooth Remineralization; Hardness; Microscopy, Electron, Scanning; Dental Enamel
PubMed: 36588492
DOI: 10.47162/RJME.63.3.08