scholarly journals Raman spectroscopy analysis of dental enamel organic and mineral composition: an experimental non-randomised study

2021 ◽  
Vol 28 (4) ◽  
pp. 118-132
Author(s):  
I. V. Bazhutova ◽  
O. А. Magsumova ◽  
O. О. Frolov ◽  
E. V. Timchenko ◽  
P. Е. Timchenko ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Periodontal Disease ◽  
High Efficiency ◽  
Tooth Enamel ◽  
Median Filter ◽  
Dental Enamel ◽  
Qualitative Assessment ◽  
Laser Source ◽  
Bleaching Procedure ◽  
Enamel Composition

Background. Contemporary dental diagnosis should supplement clinical examination with instrumental diagnostic techniques. Raman spectroscopy has become widely adopted due to high spatial resolution, non-invasiveness, the lack of strict requirements and ease of sample preparation.Objectives. A qualitative assessment of enamel mineral and organic composition dynamics using Raman spectroscopy.Methods. Raman spectroscopy was used as primary research method. The trial bench consisted of a Shamrocksr-303i high-resolution digital spectrometer with built-in DV420A-OE cooled optical detector (spectral range 200–1200 nm), RPB-785 optic fibre scattering probe integrated with LuxxMaster LML-785.0RB-04 laser source with wavelength 785 nm.Software spectrum processing was performed with Wolfram Mathematica 9. Spectra were denoised with a median filter (5 points), the approximating line (fifth order polynomial) of autofluorescent component was determined in 700–2200 cm-1 range using an iterative algorithm and then subtracted to receive isolated Raman spectra.Linear discriminant analysis (LDA) of data was performed with the IBM SPSS Statistics package. Results. The assay included 28 teeth, with 14 extracted for orthodontic indications and 14 — for chronic periodontitis. Spectral dental enamel dynamics has been established in periodontal disease and after the in-office bleaching procedure. The evidence obtained can be applicable in dental practice to verify patients at risk of periodontal disease by interpreting the tooth enamel spectral properties, as well as prior to in-office bleaching.Conclusion. We demonstrate high efficiency of Raman spectroscopy for qualitative assessment of the mineral and organic enamel composition dynamics in various settings. Raman spectroscopy is confirmed effective and versatile in various aetiologies. It was successfully applied to diagnose periodontitis by changes in the organic and mineral enamel composition and evaluate enamel after in-office bleaching.

Application of FT-Raman spectroscopy to the study of selected organometallic complexes and proteins

1990 ◽  
Vol 68 (7) ◽  
pp. 1196-1200 ◽  
Author(s):  
Steven M. Barnett ◽  
François Dicaire ◽  
Ashraf A. Ismail
Keyword(s):  
Raman Spectroscopy ◽  
Near Infrared ◽  
Metal Carbonyl ◽  
Protein A ◽  
Organometallic Complexes ◽  
Laser Source ◽  
Chromium Tricarbonyl ◽  
Ft Raman Spectroscopy ◽  
Arene Chromium Tricarbonyl ◽  
Ft Raman

The study of colored organometallic complexes by dispersive Raman spectroscopy has been limited due to fluorescence or photodecomposition caused by the visible laser used as the excitation source. As a solution to this problem, FT-Raman spectroscopy with a near-infrared laser source has been useful in lowering fluorescence or photolysis in these samples. To investigate the utility of this technique, we have obtained and assigned the FT-Raman spectra of a series of arene chromium tricarbonyl complexes and of cyclopentadienyl manganese tricarbonyl. Some bands previously unobserved by dispersive Raman spectroscopy were seen, including a band assigned to a 13CO satellite in the spectrum of methylbenzoate chromium tricarbonyl. In addition, FT-Raman data for bovine serum albumin (BSA) and Protein-A are presented. Keywords: FT-Raman spectroscopy, metal carbonyl, proteins, organometallics, near infrared.

scholarly journals Bioadhesive Curcumin-Mediated Photodynamic Inactivation and Its Potential to Cause Undesirable Effects on Dental and Restorative Surfaces

Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1458
Author(s):  
Bárbara Donadon Reina ◽  
Carolina Santezi Neto ◽  
Patrícia Petromilli Nordi Sasso Garcia ◽  
Marlus Chorilli ◽  
Giovana Maria Fioramonti Calixto ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Liquid Crystal ◽  
Tooth Enamel ◽  
Dental Enamel ◽  
Color Stability ◽  
Composite Resins ◽  
Photodynamic Inactivation ◽  
Restorative Material ◽  
Negative Effects ◽  
Restorative Materials

Curcumin-mediated Photodynamic Inactivation (PDI) has shown great potential to disinfect specific sites on tooth enamel but may involve contact with restorative materials. Thus, before use in dentistry, it is necessary to investigate whether the PDI protocol causes undesirable changes in the surfaces of aesthetic restorative materials and dental enamel. This study investigated the effect of PDI mediated by curcumin (CUR) in a liquid crystal precursor system on color stability (ΔE), surface roughness (Ra), and microhardness (kgf) of three different composite resins and bovine dental enamel specimens. The microhardness and roughness readings were performed 60 days after the treatments while the color readings were performed immediately, 24, 48, and 72 h, 7, 14, 21, 30, and 60 days after the treatments. Results showed that CUR mediated-PDI does not seem to have the potential to promote any esthetic or mechanical changes to the surface of tooth enamel and can be applied safely in clinical practice. However, the results on color, roughness, and hardness obtained for composite resins show that some negative effects can be produced, depending on the type of restorative material; more experiments must be performed with different formulations and, perhaps, with lower concentrations of CUR.

scholarly journals Micro-Raman Spectroscopy for Assessment of Periodontal Disease Follow-Up

2014 ◽  
Author(s):  
Carlo Camerlingo ◽  
Fabrizia d'Apuzzo ◽  
V. Grassia ◽  
L. Perillo ◽  
Maria Lepore
Keyword(s):  
Raman Spectroscopy ◽  
Periodontal Disease ◽  
Micro Raman Spectroscopy

In Situ Surface-Enhanced Raman Spectroscopy Characterization of Electrocatalysis with Different Nanostructures

2021 ◽  
Vol 72 (1) ◽  
Author(s):  
Bao-Ying Wen ◽  
Qing-Qi Chen ◽  
Petar M. Radjenovic ◽  
Jin-Chao Dong ◽  
Zhong-Qun Tian ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
High Efficiency ◽  
Spectroscopic Characterization ◽  
Surface Enhanced Raman Spectroscopy ◽  
Annual Review ◽  
Publication Date ◽  
Oxygen Reduction Reactions ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

As energy demands increase, electrocatalysis serves as a vital tool in energy conversion. Elucidating electrocatalytic mechanisms using in situ spectroscopic characterization techniques can provide experimental guidance for preparing high-efficiency electrocatalysts. Surface-enhanced Raman spectroscopy (SERS) can provide rich spectral information for ultratrace surface species and is extremely well suited to studying their activity. To improve the material and morphological universalities, researchers have employed different kinds of nanostructures that have played important roles in the development of SERS technologies. Different strategies, such as so-called borrowing enhancement from shell-isolated modes and shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS)-satellite structures, have been proposed to obtain highly effective Raman enhancement, and these methods make it possible to apply SERS to various electrocatalytic systems. Here, we discuss the development of SERS technology, focusing on its applications in different electrocatalytic reactions (such as oxygen reduction reactions) and at different nanostructure surfaces, and give a brief outlook on its development. Expected final online publication date for the Annual Review of Physical Chemistry, Volume 72 is April 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Multi-Frequency Heterodyne Phase Shift Technology in 3-D Measurement

2013 ◽  
Vol 774-776 ◽  
pp. 1582-1585 ◽  
Author(s):  
Le Wang ◽  
Lei Song ◽  
Li Jun Zhong ◽  
Peng Xin ◽  
Shuai Li ◽  
...  
Keyword(s):  
Phase Shift ◽  
Small Area ◽  
Fringe Pattern ◽  
Measurement Accuracy ◽  
High Efficiency ◽  
Median Filter ◽  
Distinct Advantage ◽  
Accuracy Measurement ◽  
Fringe Patterns ◽  
Spin Filtering

According to the characteristics of the fringe patterns noise, came up with a small area spin filtering noise cancellation algorithm based on parallel marker technology. It means that preprocess the fringe pattern before spin filtering, then did a median filter and calculated the stripe direction, finally used the extract the fringe direction to spin filtering of the original image. The algorithm can marked several targets in scanning process at the same time. So it has a high efficiency. The algorithm can be used in the multi-frequency heterodyne phase shift technology .And we can use the technology to complete the measurement of complex surfaces. Experimental results show that the method has a distinct advantage in measurement accuracy, measurement speed, and noise immunity.

scholarly journals Lattice Defects and Exfoliation Efficiency of 6H-SiC via H2+ Implantation at Elevated Temperature

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5723
Author(s):  
Tao Wang ◽  
Zhen Yang ◽  
Bingsheng Li ◽  
Shuai Xu ◽  
Qing Liao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Raman Spectroscopy ◽  
Nuclear Power ◽  
Power Plants ◽  
High Efficiency ◽  
Sample Surface ◽  
Lattice Defects ◽  
Transmission Electron ◽  
Sic Wafer

Silicon carbide (SiC) is an important material used in semiconductor industries and nuclear power plants. SiC wafer implanted with H ions can be cleaved inside the damaged layer after annealing, in order to facilitate the transfer of a thin SiC slice to a handling wafer. This process is known as “ion-cut” or “Smart-Cut”. It is worth investigating the exfoliation efficiency and residual lattice defects in H-implanted SiC before and after annealing. In the present paper, lattice damage in the 6H-SiC implanted by H2+ to a fluence of 5 × 1016 H2+/cm2 at 450 and 900 °C was investigated by a combination of Raman spectroscopy and transmission electron microscopy. Different levels of damage caused by dynamic annealing were observed by Raman spectroscopy and transmission electron microscopy in the as-implanted sample. Atomic force microscopy and scanning white-light interferometry were used to observe the sample surface morphology. Surface blisters and exfoliations were observed in the sample implanted at 450 °C and then annealed at 1100 °C for 15 min, whereas surface blisters and exfoliation occurred in the sample implanted at 900 °C without further thermal treatment. This finding can be attributed to the increase in the internal pressure of platelets during high temperature implantation. The exfoliation efficiency, location, and roughness after exfoliation were investigated and possible reasons were discussed. This work provides a basis for further understanding and improving the high-efficiency “ion-cut” technology.

Continuously Tuneable, Quasi-Continuous-Wave Source for Ultraviolet Resonance Raman Spectroscopy

1995 ◽  
Vol 49 (2) ◽  
pp. 247-252 ◽  
Author(s):  
Stephen J. Doig ◽  
Franklyn G. Prendergast
Keyword(s):  
Raman Spectroscopy ◽  
Continuous Wave ◽  
Uv Light ◽  
Resonance Raman Spectroscopy ◽  
Resonance Raman ◽  
Laser Source ◽  
Ultraviolet Region ◽  
Wave Source ◽  
The Third ◽  
Ultraviolet Resonance Raman

A continuously tuneable, quasi-continuous-wave (cw), ultraviolet source for resonance Raman spectroscopy has been developed. The third and fourth harmonics of a picosecond mode-locked titanium: sapphire laser were generated in nonlinear crystals. The pulses which resulted from these processes were spectrally narrow (10–15 cm−1) and had low peak powers (<1 kW), while the system as a whole provides high average powers. Fourth-harmonic wavelengths were generated from 208 to 230 nm with average powers from 15 to 40 mW, while the third harmonic ranged from 255 to 305 nm with over 90 mW of power. The UV light was well collimated and focused well, and the power was stable for hours. Resonance Raman spectra of tryptophan and phenylalanine were recorded to demonstrate the practical application of this system. Spectra with excellent signal-to-noise ratios were recorded in 6 min with no deleterious effects from nonlinear processes. The selective enhancement of tryptophan scattering in a 1:10 molar solution of tryptophan to phenylalanine makes clear the advantage of a continuously tuneable UV source. Elaboration of this system to the full tuning range of titanium: sapphire lasers will create a laser source suitable for resonance Raman spectroscopy throughout the ultraviolet region (205–400 nm).

20.2: High-Efficiency Green Laser Source for Compact Projectors

2009 ◽  
Vol 40 (1) ◽  
pp. 265 ◽  
Author(s):  
John Khaydarov ◽  
Andrei Shchegrov ◽  
Stepan Essaian ◽  
Greg Nemet ◽  
Suren Soghomonyan ◽  
...  
Keyword(s):  
High Efficiency ◽  
Green Laser ◽  
Laser Source

scholarly journals Molecular Mechanisms of Dental Enamel Formation

1995 ◽  
Vol 6 (2) ◽  
pp. 84-108 ◽  
Author(s):  
J.P. Simmer ◽  
A.G. Fincham
Keyword(s):  
Molecular Mechanisms ◽  
Tooth Enamel ◽  
Dental Enamel ◽  
Calcium Hydroxyapatite ◽  
Octacalcium Phosphate ◽  
Growth Patterns ◽  
Degree Of Saturation ◽  
Crystal Habit ◽  
Supersaturated Solution ◽  
Unit Cells

Tooth enamel is a unique mineralized tissue in that it is acellular, is more highly mineralized, and is comprised of individual crystallites that are larger and more oriented than other mineralized tissues. Dental enamel forms by matrix- mediated biomineralization. Enamel crystallites precipitate from a supersaturated solution within a well-delineated biological compartment. Mature enamel crystallites are comprised of non-stoichiometric carbonated calcium hydroxyapatite. The earliest crystallites appear suddenly at the dentino-enamel junction (DEJ) as rapidly growing thin ribbons. The shape and growth patterns of these crystallites can be interpreted as evidence for a precursor phase of octacalcium phosphate (OCP). An OCP crystal displays on its (100) face a surface that may act as a template for hydroxyapatite (OHAp) precipitation. Octacalcium phosphate is less stable than hydroxyapatite and can hydrolyze to OHAp. During this process, one unit cell of octacalcium phosphate is converted into two unit cells of hydroxyapatite. During the precipitation of the mineral phase, the degree of saturation of the enamel fluid is regulated. Proteins in the enamel matrix may buffer calcium and hydrogen ion concentrations as a strategy to preclude the precipitation of competing calcium phosphate solid phases. Tuftelin is an acidic enamel protein that concentrates at the DEJ and may participate in the nucleation of enamel crystals. Other enamel proteins may regulate crystal habit by binding to specific faces of the mineral and inhibiting growth. Structural analyses of recombinant amelogenin are consistent with a functional role in establishing and maintaining the spacing between enamel crystallites.

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