scholarly journals Atomic-scale compositional mapping reveals Mg-rich amorphous calcium phosphate in human dental enamel

2016 ◽  
Vol 2 (9) ◽  
pp. e1601145 ◽  
Author(s):  
Alexandre La Fontaine ◽  
Alexander Zavgorodniy ◽  
Howgwei Liu ◽  
Rongkun Zheng ◽  
Michael Swain ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Dental Enamel ◽  
Atom Probe ◽  
Vital Role ◽  
The Body ◽  
Atomic Scale ◽  
Chemical Attack ◽  
Direct Observations

Human dental enamel, the hardest tissue in the body, plays a vital role in protecting teeth from wear as a result of daily grinding and chewing as well as from chemical attack. It is well established that the mechanical strength and fatigue resistance of dental enamel are derived from its hierarchical structure, which consists of periodically arranged bundles of hydroxyapatite (HAP) nanowires. However, we do not yet have a full understanding of the in vivo HAP crystallization process that leads to this structure. Mg2+ ions, which are present in many biological systems, regulate HAP crystallization by stabilizing its precursor, amorphous calcium phosphate (ACP), but their atomic-scale distribution within HAP is unknown. We use atom probe tomography to provide the first direct observations of an intergranular Mg-rich ACP phase between the HAP nanowires in mature human dental enamel. We also observe Mg-rich elongated precipitates and pockets of organic material among the HAP nanowires. These observations support the postclassical theory of amelogenesis (that is, enamel formation) and suggest that decay occurs via dissolution of the intergranular phase. This information is also useful for the development of more accurate models to describe the mechanical behavior of teeth.

scholarly journals Ph-activated nano-amorphous calcium phosphate-based cement to reduce dental enamel demineralization

2017 ◽  
Vol 45 (8) ◽  
pp. 1778-1785 ◽  
Author(s):  
Mary A. S. Melo ◽  
Michael D. Weir ◽  
Vanara F. Passos ◽  
Michael Powers ◽  
Hockin H. K. Xu
Keyword(s):  
Calcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Dental Enamel ◽  
Enamel Demineralization

In Vivo Study of Two Carbamide Peroxide Gels with Different Desensitizing Agents

10.2341/07-10 ◽  
2007 ◽  
Vol 32 (6) ◽  
pp. 549-555 ◽  
Author(s):  
B. A. Matis ◽  
M. A. Cochran ◽  
G. J. Eckert ◽  
J. I. Matis
Keyword(s):  
Calcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Clinical Relevance ◽  
Potassium Nitrate ◽  
In Vivo Study ◽  
Carbamide Peroxide ◽  
Desensitizing Agents

Clinical Relevance Under the conditions of this study, 15% carbamide peroxide with potassium nitrate and fluoride exhibited greater bleaching potential but exhibited no difference in sensitivity compared to 16% carbamide peroxide with amorphous calcium phosphate.

scholarly journals Phosphoserine Functionalized Cements Preserve Metastable Phases, and Reprecipitate Octacalcium Phosphate, Hydroxyapatite, Dicalcium Phosphate, and Amorphous Calcium Phosphate, during Degradation, In Vitro

2019 ◽  
Vol 10 (4) ◽  
pp. 54 ◽  
Author(s):  
Joseph Lazraq Bystrom ◽  
Michael Pujari-Palmer
Keyword(s):  
Calcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Octacalcium Phosphate ◽  
Ionic Concentration ◽  
Strong Adhesion ◽  
Acidic Conditions ◽  
Rapid Transformation ◽  
Comparable Mass

Phosphoserine modified cements (PMC) exhibit unique properties, including strong adhesion to tissues and biomaterials. While TTCP-PMCs remodel into bone in vivo, little is known regarding the bioactivity and physiochemical changes that occur during resorption. In the present study, changes in the mechanical strength and composition were evaluated for 28 days, for three formulations of αTCP based PMCs. PMCs were significantly stronger than unmodified cement (38–49 MPa vs. 10 MPa). Inclusion of wollastonite in PMCs appeared to accelerate the conversion to hydroxyapatite, coincident with slight decrease in strength. In non-wollastonite PMCs the initial compressive strength did not change after 28 days in PBS (p > 0.99). Dissolution/degradation of PMC was evaluated in acidic (pH 2.7, pH 4.0), and supersaturated fluids (simulated body fluid (SBF)). PMCs exhibited comparable mass loss (<15%) after 14 days, regardless of pH and ionic concentration. Electron microscopy, infrared spectroscopy, and X-ray analysis revealed that significant amounts of brushite, octacalcium phosphate, and hydroxyapatite reprecipitated, following dissolution in acidic conditions (pH 2.7), while amorphous calcium phosphate formed in SBF. In conclusion, PMC surfaces remodel into metastable precursors to hydroxyapatite, in both acidic and neutral environments. By tuning the composition of PMCs, durable strength in fluids, and rapid transformation can be obtained.

scholarly journals Real Time In Vivo Confocal Microscopic Analysis of the Enamel Remineralization by Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP): A Clinical Proof-of-Concept Study

2020 ◽  
Vol 10 (12) ◽  
pp. 4155
Author(s):  
Maria Contaldo ◽  
Dario Di Stasio ◽  
Fedora della Vella ◽  
Dorina Lauritano ◽  
Rosario Serpico ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Confocal Laser ◽  
Proof Of Concept ◽  
Concept Study ◽  
Casein Phosphopeptide

Enamel defects (EDs) are qualitative and/or quantitative disturbances of the dental surface. To date, the responsiveness to remineralizing treatments has been studied ex vivo, on dental sections from extracted teeth. The present research aims to establish if in vivo reflectance confocal laser scanning microscopy is able to visualize the changes in the enamel architecture on living teeth, before, during and after remineralizing treatments by casein phosphopeptide-amorphous calcium phosphate (CPP-ACP). As proof-of-concept study, 17 consecutive children affected by EDs were enrolled and 38 EDs were considered. A CPP-ACP mousse was applied twice a week for 6 weeks and clinical and microscopic images were collected before, during and after the treatment for evaluating the changes occurred. For in vivo microscopic imaging, a reflectance confocal laser scanning microscope (RCM) for in vivo use was adopted. In this study RCM was proven to be able to visualize in vivo and at microscopic resolution the changes occurred during the remineralizing processes without needing for dental extractions and histopathological procedures. This in vivo RCM capability could encourage its clinical application in monitoring responsiveness to enamel therapies.

The Role of Albumin in Developing Rodent Dental Enamel: A Possible Explanation for White Spot Hypoplasia

1992 ◽  
Vol 71 (6) ◽  
pp. 1270-1274 ◽  
Author(s):  
C. Robinson ◽  
J. Kirkham ◽  
S.J. Brookes ◽  
R.C. Shore
Keyword(s):  
Monoclonal Antibodies ◽  
Calcium Phosphate ◽  
Gel Electrophoresis ◽  
Crystal Size ◽  
Dental Enamel ◽  
Maturation Stage ◽  
Crystallite Growth

The uptake of serum albumin by maturation-stage rodent enamel and the resulting effects on the growth of enamel crystallites were investigated in vitro. Albumin uptake was demonstrated by means of gel electrophoresis and confirmed by Western blotting with use of monoclonal antibodies. Measurement of crystal size was carried out by direct TEM measurement of enamel crystallite outlines after incubations in metastable solutions of calcium phosphate. The ability of endogenous enamel enzymes to degrade albumin was investigated by substrate-specific zymography. The results showed that albumin could be taken up by maturation-stage enamel and produce inhibition of crystallite growth. There was no detectable proteolytic activity in the enamel against albumin substrate, which suggests that albumin entering enamel by extravasation in vivo may produce incomplete tissue maturation, resulting in a white, opaque appearance on eruption.

Evaluation of Dentin Tubule Sealing Rate Improved by Attaching Ultrathin Amorphous Calcium Phosphate Sheet

2014 ◽  
Vol 631 ◽  
pp. 258-261 ◽  
Author(s):  
Nobuhiro Kato ◽  
Arata Isai ◽  
Ei Yamamoto ◽  
Hiroaki Nishikawa ◽  
Masanobu Kusunoki ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Tooth Enamel ◽  
Dental Enamel ◽  
Gingival Recession ◽  
Dentin Hypersensitivity ◽  
Mechanical Stimuli ◽  
Dentin Tubule ◽  
Human Dentin ◽  
Dentin Tubules

Dentin hypersensitivity is induced by mechanical stimuli or heat stimuli applied via dentin tubules exposed by lost of dental enamel or gingival recession. Common treatments for dentin hypersensitivity are resin coating or laser irradiation. However, these treatments have some problems such as poor biocompatibility or insufficient durability. We have been developing a treatment that creates artificial tooth enamel by attaching flexible ultrathin calcium phosphate sheet having a crystal structure similar to that of tooth enamel to seal the dentin tubules. In this study, the quantitative evaluation of dentin tubule sealing rate improved by attaching ultrathin amorphous calcium phosphate (APC) sheet on human dentin is presented. The obtained sealing-rate by APC sheet application was 70.9 ± 4.8 %.

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