Ultrasound as a Tool to Measure the Wear of Human Tooth Enamel

Author(s):  
R. S. Dwyer-Joyce ◽  
R. Lewis ◽  
M. Goodman

A reliable tool for assessing the extent of human enamel wear would be useful to dental practitioners. Current in-vivo methods for determining tooth wear are largely qualitative in nature or depend on measurements taken from tooth impressions, which is very time consuming. The aim of this work was to investigate the feasibility of using ultrasound to measure enamel thickness with a view to developing an in-vivo tool for enamel wear assessment. Three different ultrasonic techniques were used in-vitro to take measurements of enamel on extracted teeth. The first used a focusing immersion transducer (25 MHz) and a time of flight approach to obtain enamel thickness. The other two techniques used planar contact probes (10 MHz), the first with a time of flight approach and the second with a resonance method to determine enamel thickness. The results were compared with direct measurements of sectioned teeth. All three methods showed good correlation with these measurements. The contact probe technique was the easiest measurement to carry out, which would also be the simplest to implement in a measurement tool. While the resonance measurements obtained were good, the time of flight approach was thought to be most likely to obtain accurate repeatable measurements.

2012 ◽  
Vol 6 (1) ◽  
pp. 226-234 ◽  
Author(s):  
Daniela Guzmán-Uribe ◽  
Keila Neri Alvarado Estrada ◽  
Amaury de Jesús Pozos Guillén ◽  
Silvia Martín Pérez ◽  
Raúl Rosales Ibáñez

Application of regenerative medicine technology provides treatment for patients with several clinical problems, like loss of tissue and its function. The investigation of biological tooth replacement, dental tissue engineering and cell culture, scaffolds and growth factors are considered essential. Currently, studies reported on the making of threedimensional tissue constructs focused on the use of animal cells in the early stages of embryogenesis applied to young biomodels. The purpose of this study was the development and characterization of a three-dimensional tissue construct from human dental cells. The construct was detached, cultured and characterized in mesenchymal and epithelial cells of a human tooth germ of a 12 year old patient. The cells were characterized by specific membrane markers (STRO1, CD44), making a biocomplex using Pura Matrix as a scaffold, and it was incubated for four days and transplanted into 30 adult immunosuppressed male Wistar rats. They were evaluated at 6 days, 10 days and 2 months, obtaining histological sections stained with hematoxylin and eosin. Cell cultures were positive for specific membrane markers, showing evident deviations in morphology under phase contrast microscope. Differentiation and organization were noted at 10 days, while the constructs at 2 months showed a clear difference in morphology, organization and cell type. It was possible to obtain a three-dimensional tissue construct from human dental ectomesenchymal cells achieving a degree of tissue organization that corresponds to the presence of cellular stratification and extracellular matrix.


Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2140 ◽  
Author(s):  
Xinchi Feng ◽  
Yang Li ◽  
Chenxi Guang ◽  
Miao Qiao ◽  
Tong Wang ◽  
...  

Linarin, a flavone glycoside, is considered to be a promising natural product due to its diverse pharmacological activities, including analgesic, antipyretic, anti-inflammatory and hepatoprotective activities. In this research, the metabolites of linarin in rat intestinal flora and biosamples were characterized using ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS/MS). Three ring cleavage metabolites (4-hydroxybenzoic acid, 4-hydroxy benzaldehyde and phloroglucinol) were detected after linarin was incubated with rat intestinal flora. A total of 17 metabolites, including one ring cleavage metabolite (phloroglucinol), were identified in rat biosamples after oral administration of linarin. These results indicate that linarin was able to undergo ring fission metabolism in intestinal flora and that hydrolysis, demethylation, glucuronidation, sulfation, glycosylation, methylation and ring cleavage were the major metabolic pathways. This study provides scientific support for the understanding of the metabolism of linarin and contributes to the further development of linarin as a drug candidate.


2006 ◽  
Vol 97 (4) ◽  
pp. 836-848 ◽  
Author(s):  
Vincenzo D'Antò ◽  
Monica Cantile ◽  
Maria D'Armiento ◽  
Giulia Schiavo ◽  
Gianrico Spagnuolo ◽  
...  

2018 ◽  
Vol 110 (5) ◽  
pp. 486-490
Author(s):  
Leila Basir ◽  
Somayeh Kalhori ◽  
Ahmad Zare Javid ◽  
Mashallah Khaneh Masjedi

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2113 ◽  
Author(s):  
Chao Hong ◽  
Ping Yang ◽  
Shuping Li ◽  
Yizhen Guo ◽  
Dan Wang ◽  
...  

Background: Ginsenoside Rg5 has been proved to have a wide range of pharmacological activities. However, the in vitro and in vivo metabolism pathways of ginsenosides are still unclear, which impedes the understanding of their in vivo fate. In this paper, the possible metabolic process of Rg5 was studied and the metabolites are identified. Methods: Samples from rat liver microsomes (RLMs) in vitro and from rat urine, plasma and feces in vivo were collected for analysis after oral administration of Rg5. A rapid analysis technique using ultra-performance liquid chromatography (UPLC)/quadrupole-time-of-flight mass spectrometry (QTOF-MS) was applied for detecting metabolites of Rg5 both in vitro and in vivo. Results: A feasible metabolic pathway was proposed and described for ginsenoside Rg5. A total of 17 metabolic products were detected in biological samples, including the RLMs (four), rat urine (two), feces (13) and plasma (four). Fifteen of them have never been reported before. Oxidation, deglycosylation, deoxidation, glucuronidation, demethylation and dehydration were found to be the major metabolic reactions of Rg5. Conclusions: The present study utilized a reliable and quick analytical tool to explore the metabolism of Rg5 in rats and provided significant insights into the understanding of the metabolic pathways of Rg5 in vitro and in vivo. The results could be used to not only evaluate the efficacy and safety of Rg5, but also identify potential active drug candidates from the metabolites.


2000 ◽  
Vol 14 (1) ◽  
pp. 22-28 ◽  
Author(s):  
U. Lendenmann ◽  
J. Grogan ◽  
F.G. Oppenheim

The acquired enamel pellicle is an organic film covering the surfaces of teeth. When this film was first discovered, it was thought to be of embryologic origin. Only in the middle of this century did it become clear that it was acquired after tooth eruption. Initially, the small amounts of material that could be obtained have virtually limited the investigation of pellicle proteins to amino acid analysis. Nevertheless, this technique revealed that the pellicle is mainly proteinaceous and is formed by selective adsorption of salivary proteins on tooth enamel. Later, immunologic techniques allowed for the identification of many salivary and fewer non-salivary proteins as constituents of pellicle. However, to this date, isolation and direct biochemical characterization of in vivo pellicle protein have not been possible, because only a few micrograms can be obtained from a single donor. Therefore, the composition and structure of the acquired enamel pellicle are still essentially unknown. Information on the functions of pellicle has been obtained mainly from in vitro experiments carried out with saliva-coated hydroxyapatite and enamel discs. It was found that pellicle protects enamel by reducing demineralization upon acid challenge. Improved pellicle harvesting procedures and analysis by state-of-the-art proteomics with mass spectroscopy approaches promise to make major inroads into the characterization of enamel pellicle.


Sign in / Sign up

Export Citation Format

Share Document