Structural optimization and amorphous calcium phosphate mineralization in sensory setae of a terrestrial crustacean (Isopoda: Oniscidea)

Micron ◽  
2018 ◽  
Vol 112 ◽  
pp. 26-34 ◽  
Author(s):  
Miloš Vittori ◽  
Vesna Srot ◽  
Birgit Bussmann ◽  
Felicitas Predel ◽  
Peter A. van Aken ◽  
...  
Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1373
Author(s):  
Miloš Vittori ◽  
Vesna Srot ◽  
Lidija Korat ◽  
Matjaž Rejec ◽  
Pavel Sedmak ◽  
...  

Exposed regions of the arthropod exoskeleton have specialized structure and mineral composition. Their study can provide insights into the evolutionary optimization of the cuticle as a material. We determined the structural and compositional features of claws in the crustacean Ligia pallasii using X-ray micro-computed tomography, scanning electron microscopy (SEM), and analytical scanning transmission electron microscopy (STEM). In addition, we used nanoindentation to determine how these features fine-tune the mechanical properties of the claw cuticle. We found that the inner layer of the claw cuticle—the endocuticle—contains amorphous calcium phosphate, while the outer layer—the exocuticle—is not mineralized and contains elevated amounts of bromine. While the chitin–protein fibers in crustacean exoskeletons generally shift their orientation, they are aligned axially in the claws of L. pallasii. As a consequence, the claw cuticle has larger elastic modulus and hardness in the axial direction. We show that amorphous calcium phosphate mineralization and the brominated cuticle are widespread in isopod crustaceans inhabiting terrestrial habitats. We discuss how the features of the claw cuticle may aid in minimizing the likelihood of fracture. Ultimately, our study points out the features that increase the durability of thin skeletal elements.


2021 ◽  
pp. 1-10
Author(s):  
Ahmed Sleibi ◽  
Anwar R. Tappuni ◽  
Aylin Baysan

Different formulas of topical fluoride have been used to manage root carious lesions. This clinical trial aimed to investigate the efficacy of a dental varnish containing casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and fluoride compared with fluoride alone in reversing/arresting root caries in xerostomic patients over 1 year. A total of 80 patients (age range 45–92 years) with primary root caries (<i>n</i> = 184 root carious lesions) and unstimulated salivary flow rate of &#x3c;0.2 mL/min were randomly allocated to receive either dental varnish containing CPP-ACP and 5% fluoride (group 1: MI varnish; GC, Japan) (<i>n</i> = 41, 83 lesions), or dental varnish with 5% fluoride alone (group 2: NUPRO White; Dentsply, USA) (<i>n</i> = 39, 101 lesions). Clinical assessments with Severity Index (SI) for root caries, DIAGNOdent measurements, and varnish application were carried out at baseline, 3, 6, and 12 months. Standard oral hygiene instructions with 1,450 ppm fluoride toothpastes were provided for both groups. After 3 months, 63.9% (<i>n</i> = 46) of root caries in group 1 became hard (SI: 0) compared with 39.3% (<i>n</i> = 35) in group 2 (<i>p</i> &#x3c; 0.01). After 6 and 12 months, the differences in SI were insignificant (group 1, <i>n</i> = 60, 83.3%) (group 2, <i>n</i> = 66, 74.2%) (<i>p</i> = 0.36), and (group 1, <i>n</i> = 60, 89.6%) (group 2, <i>n</i> = 67, 81.7%, <i>n</i> = 1 soft, 1.2%) (<i>p</i> = 0.29), respectively. In both groups, noncavitated leathery lesions were more likely to become hard when compared to the cavitated root caries. A significant decrease in plaque index, surface roughness, lesion dimension, and DIAGNOdent readings with a significant increase in lesion distance from the gingival margin was reported in both groups (<i>p</i> &#x3c; 0.05). This study has provided evidence that fluoride dental varnish either with or without calcium and phosphate has the potential to arrest/reverse root caries, especially noncavitated lesions for patients with xerostomia.


Author(s):  
Alexandria J. Hoeher ◽  
Sebastian T. Mergelsberg ◽  
Olaf J. Borkiewicz ◽  
F. Marc Michel

2021 ◽  
Vol 106 ◽  
pp. 103582
Author(s):  
Armelia Sari Widyarman ◽  
Nadeeka S. Udawatte ◽  
Citra Fragrantia Theodorea ◽  
Anie Apriani ◽  
Mario Richi ◽  
...  

2015 ◽  
Vol 159 ◽  
pp. 288-300 ◽  
Author(s):  
I. Navarro-Blasco ◽  
A. Duran ◽  
M. Pérez-Nicolás ◽  
J.M. Fernández ◽  
R. Sirera ◽  
...  

2008 ◽  
Vol 20 (1) ◽  
pp. 11-13 ◽  
Author(s):  
María C. Gutiérrez ◽  
Matías Jobbágy ◽  
María L. Ferrer ◽  
Francisco del Monte

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