Micro-Raman Spectroscopy Reveals the Presence of Octacalcium Phosphate and Whitlockite in Association with Bacteria-Free Zones Within the Mineralized Dental Biofilm

2019 ◽  
Vol 25 (1) ◽  
pp. 129-134 ◽  
Author(s):  
Furqan A. Shah
Keyword(s):  
Raman Spectroscopy ◽  
Octacalcium Phosphate ◽  
Carbonate Content ◽  
Native Bone ◽  
Dental Biofilm ◽  
Micro Raman Spectroscopy ◽  
Carbonated Apatite ◽  
Backscattered Electron ◽  
Nondestructive Investigation ◽  
Mineral Crystallinity

AbstractThrough a correlative analytical approach encompassing backscattered electron scanning electron microscopy (BSE-SEM), energy dispersive X-ray spectroscopy (EDX), and micro-Raman spectroscopy, the composition of the mineralized biofilm around a dental implant, retrieved due to peri-implantitis, was investigated. The mineralized biofilm contains two morphologically distinct regions: (i) bacteria-containing zones (Bact+), characterized by aggregations of unmineralized and mineralized bacteria, and intermicrobial mineralization, and (ii) bacteria-free zones (Bact−), comprised mainly of randomly oriented mineral platelets. Intramicrobial mineralization, within Bact+, appears as smooth, solid mineral deposits resembling the morphologies of dental plaque bacteria. Bact− is associated with micrometer-sized Mg-rich mineral nodules. The Ca/P ratio of Bact+ is higher than Bact−. The inorganic phase of Bact+ is carbonated apatite (CHAp), while that of Bact− is predominantly octacalcium phosphate (OCP) and whitlockite (WL) inclusions. Compared with native bone, the inorganic phase of Bact+ (i.e., CHAp) exhibits higher mineral crystallinity, lower carbonate content, and lower Ca/P, C/Ca, Mg/Ca, and Mg/P ratios. The various CaPs found within the mineralized dental biofilm (CHAp, OCP, and WL) are related to the local presence/absence of bacteria. In combination with BSE-SEM and EDX, micro-Raman spectroscopy is a valuable analytical tool for nondestructive investigation of mineralized dental biofilm composition and development.

Raman Spectra of Human Dental Calculus

1993 ◽  
Vol 72 (12) ◽  
pp. 1609-1613 ◽  
Author(s):  
H. Tsuda ◽  
J. Arends
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Octacalcium Phosphate ◽  
Spot Size ◽  
Spectral Features ◽  
Dental Calculus ◽  
Micro Raman Spectroscopy ◽  
Vibrational Bands ◽  
First Time ◽  
Mineral Constituents

Raman spectra of human dental calculus have been observed for the first time by use of micro-Raman spectroscopy. The spectral features of calculus were influenced easily by heating caused by laser irradiation. Therefore, the measurements were carried out at relatively low power (5 mW, 1-μm spot size). The spectra could be characterized as phosphate vibrational bands due to the v1, v2, v 3, and v4 modes. The overall spectral features did not resemble those of pure minerals such as brushite, octacalcium phosphate, and hydroxyapatite. There were spectral differences among mixed calculus particles obtained from 18 adults, probably due to variations in local mineral composition and differences among patients. However, the averaged spectral features did not vary significantly with formation period from 1 to 6 months. Freshly removed and stored (5-11 months) calculus also gave comparable Raman spectra. Measurements on a fractured sample indicated that Raman spectra at saliva and dentin interfaces are nearly identical, and major mineral constituents may not vary significantly along the growth axis of calculus.

scholarly journals Micro-Nano Surface Characterization and Bioactivity of a Calcium Phosphate-Incorporated Titanium Implant Surface

2021 ◽  
Vol 12 (1) ◽  
pp. 3
Author(s):  
Fausto Zamparini ◽  
Carlo Prati ◽  
Luigi Generali ◽  
Andrea Spinelli ◽  
Paola Taddei ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Calcium Phosphate ◽  
Photoelectron Spectroscopy ◽  
Surface Characterization ◽  
Textured Surface ◽  
Implant Surface ◽  
Mineral Layer ◽  
X Ray ◽  
Micro Raman Spectroscopy ◽  
Carbonated Apatite

The surface topography of dental implants and micro-nano surface characterization have gained particular interest for the improvement of the osseointegration phases. The aim of this study was to evaluate the surface micro-nanomorphology and bioactivity (apatite forming ability) of Ossean® surface, a resorbable blast medium (RBM) blasted surface further processed through the incorporation of a low amount of calcium phosphate. The implants were analyzed using environmental scanning electronic microscopy (ESEM), connected to Energy dispersive X-ray spectroscopy (EDX), field emission gun SEM-EDX (SEM-FEG) micro-Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) before and after immersion in weekly refreshed Hank’s balanced salt solution (HBSS) for 28 days. The analysis of the samples before immersion showed a moderately rough surface, with micropits and microgrooves distributed on all of the surface; EDX microanalysis revealed the constitutional elements of the implant surface, namely titanium (Ti), aluminum (Al) and vanadium (V). Limited traces of calcium (Ca) and phosphorous (P) were detected, attributable to the incorporated calcium phosphate. No traces of calcium phosphate phases were detected by micro-Raman spectroscopy. ESEM analysis of the implant aged in HBSS for 28 days revealed a significantly different surface, compared to the implant before immersion. At original magnifications <2000×, a homogeneous mineral layer was present on all the surface, covering all the pits and microgrooves. At original magnifications ≥10,000×, the mineral layer revealed the presence of small microspherulites. The structure of these spherulites (approx. 2 µm diameter) was observed in nanoimmersion mode revealing a regular shape with a hairy-like contour. Micro-Raman analysis showed the presence of B-type carbonated apatite on the implant surface, which was further confirmed by XPS analysis. This implant showed a micro-nano-textured surface supporting the formation of a biocompatible apatite when immersed in HBSS. These properties may likely favor bone anchorage and healing by stimulation of mineralizing cells.

Micro-Raman Spectroscopy Evaluation of the Local Mechanical Stress in Shallow Trench Isolation CMOS Structures: Correlation with Defect Generation and Diode Leakage

1998 ◽  
Author(s):  
I. De Wolf ◽  
G. Groeseneken ◽  
H.E. Maes ◽  
M. Bolt ◽  
K. Barla ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Mechanical Stress ◽  
Defect Formation ◽  
Active Area ◽  
Wet Oxidation ◽  
Leakage Currents ◽  
Shallow Trench Isolation ◽  
Micro Raman Spectroscopy ◽  
Silicon Devices ◽  
Trench Isolation

Abstract It is shown, using micro-Raman spectroscopy, that Shallow Trench Isolation introduces high stresses in the active area of silicon devices when wet oxidation steps are used. These stresses result in defect formation in the active area, leading to high diode leakage currents. The stress levels are highest near the outer edges of line structures and at square structures. They also increase with decreasing active area dimensions.

Micro-Raman spectroscopy of Shang oracle bone inscriptions

2021 ◽  
Vol 37 ◽  
pp. 102910
Author(s):  
Jhih-Huei Liu ◽  
Weiying Ke ◽  
Ming-chorng Hwang ◽  
Kuang Yu Chen
Keyword(s):  
Raman Spectroscopy ◽  
Micro Raman Spectroscopy

scholarly journals Use of WetSEM® capsules for convenient multimodal scanning electron microscopy, energy dispersive X-ray analysis, and micro Raman spectroscopy characterisation of technetium oxides

2021 ◽  
Author(s):  
D. J. Bailey ◽  
M. C. Stennett ◽  
J. Heo ◽  
N. C. Hyatt
Keyword(s):  
Raman Spectroscopy ◽  
Low Cost ◽  
Powder Materials ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Micro Raman Spectroscopy ◽  
Hazard And Risk ◽  
Sem Imaging ◽  
General User ◽  
532 Nm

AbstractSEM–EDX and Raman spectroscopy analysis of radioactive compounds is often restricted to dedicated instrumentation, within radiological working areas, to manage the hazard and risk of contamination. Here, we demonstrate application of WetSEM® capsules for containment of technetium powder materials, enabling routine multimodal characterisation with general user instrumentation, outside of a controlled radiological working area. The electron transparent membrane of WetSEM® capsules enables SEM imaging of submicron non-conducting technetium powders and acquisition of Tc Lα X-ray emission, using a low cost desktop SEM–EDX system, as well as acquisition of good quality μ-Raman spectra using a 532 nm laser.

scholarly journals Influence of Different Conditioning Treatments on The Bond Integrity of Root Dentin to rGO Infiltrated Dentin Adhesive. SEM, EDX, FTIR and MicroRaman Study

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1555
Author(s):  
Firas Alqarawi ◽  
Mazen Alkahtany ◽  
Khalid Almadi ◽  
Afnan Gassem ◽  
Faris Alshahrani ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Bond Strength ◽  
Strength Test ◽  
Control Group ◽  
Micro Raman Spectroscopy ◽  
Fiber Posts ◽  
Root Canal Disinfection ◽  
Reduced Graphene ◽  
Root Dentin ◽  
Push Out

The present study aimed to synthesize and equate the mechanical properties and dentin interaction of two adhesives; experimental adhesive (EA) and 5 wt.% reduced graphene oxide rGO) containing adhesive. Scanning electron microscopy (SEM)-Energy-dispersive X-ray spectroscopy (EDX), Micro-Raman spectroscopy, push-out bond strength test, and Fourier Transform Infrared (FTIR) spectroscopy were employed to study nano-bond strength, degree of conversion (DC), and adhesive-dentin interaction. The EA was prepared, and rGO particles were added to produce two adhesive groups, EA-rGO-0% (control) and rGO-5%. The canals of sixty roots were shaped and prepared, and fiber posts were cemented. The specimens were further alienated into groups based on the root canal disinfection technique, including 2.5% sodium hypochlorite (NaOCl), Photodynamic therapy (PDT), and ER-CR-YSGG laser (ECYL). The rGO nanoparticles were flake-shaped, and EDX confirmed the presence of carbon (C). Micro-Raman spectroscopy revealed distinct peaks for graphene. Push-out bond strength test demonstrated highest values for the EA-rGO-0% group after NaOCl and PDT conditioning whereas, rGO-5% showed higher values after ECYL conditioning. EA-rGO-0% presented greater DC than rGO-5% adhesive. The rGO-5% adhesive demonstrated comparable push-out bond strength and rheological properties to the controls. The rGO-5% demonstrated acceptable DC (although lower than control group), appropriate dentin interaction, and resin tag establishment.

scholarly journals New minerals tsangpoite Ca5(PO4)2(SiO4) and matyhite Ca9(Ca0.5□0.5)Fe(PO4)7 from the D'Orbigny angrite

2018 ◽  
Vol 83 (02) ◽  
pp. 293-313 ◽  
Author(s):  
Shyh-Lung Hwang ◽  
Pouyan Shen ◽  
Hao-Tsu Chu ◽  
Tzen-Fu Yui ◽  
Maria-Euginia Varela ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Raman Spectroscopy ◽  
Electron Diffraction ◽  
Grain Boundary ◽  
Electron Probe ◽  
Formation Mechanisms ◽  
Formula Unit ◽  
Micro Raman Spectroscopy ◽  
The Common ◽  
Oxygen Atoms

AbstractTsangpoite, ideally Ca5(PO4)2(SiO4), the hexagonal polymorph of silicocarnotite, and matyhite, ideally Ca9(Ca0.5□0.5)Fe(PO4)7, the Fe-analogue of Ca-merrillite, were identified from the D'Orbigny angrite meteorite by electron probe microanalysis, electron microscopy and micro-Raman spectroscopy. On the basis of electron diffraction, the symmetry of tsangpoite was shown to be hexagonal,P63/morP63, witha= 9.489(4) Å,c= 6.991(6) Å,V= 545.1(6) Å3andZ= 2 for 12 oxygen atoms per formula unit, and that of matyhite was shown to be trigonal,R3c, witha= 10.456 (7) Å,c= 37.408(34) Å,V= 3541.6 (4.8) Å3andZ= 6 for 28 oxygen atoms per formula unit. On the basis of their constant association with the grain-boundary assemblage: Fe sulfide + ulvöspinel + Al–Ti-bearing hedenbergite + fayalite–kirschsteinite intergrowth, the formation of tsangpoite and matyhite, along with kuratite (the Fe-analogue of rhönite), can be readily rationalised as crystallisation from residue magmas at the final stage of the D'Orbigny meteorite formation. Alternatively, the close petrographic relations between tsangpoite/matyhite and the resorbed Fe sulfide rimmed by fayalite + kirschsteinite symplectite, such as the nucleation of tsangpoite in association with magnetite ± other phases within Fe sulfide and the common outward growth of needle-like tsangpoite or plate-like matyhite from the fayalite–kirschsteinite symplectic rim of Fe sulfide into hedenbergite, infer that these new minerals and the grain-boundary assemblage might represent metasomatic products resulting from reactions between an intruding metasomatic agent and the porous olivine–plagioclase plate + fayalite-kirschsteinite overgrowth + augite + Fe sulfide aggregates. Still further thermochemical and kinetics evidence is required to clarify the exact formation mechanisms/conditions of the euhedral tsangpoite, matyhite and kuratite at the grain boundary of the D'Orbigny angrite.

Micro-Raman spectroscopy of thaumasite

2001 ◽  
Vol 31 (3) ◽  
pp. 421-424 ◽  
Author(s):  
A.R. Brough ◽  
A. Atkinson
Keyword(s):  
Raman Spectroscopy ◽  
Micro Raman Spectroscopy
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