The Experts below are selected from a list of 49266 Experts worldwide ranked by ideXlab platform
Katherine E Frederick - One of the best experts on this subject based on the ideXlab platform.
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Surfactant-modified β-TCP: structure, properties, and in vitro remineralization of subsurface enamel lesions
Journal of Materials Science: Materials in Medicine, 2010Co-Authors: Robert L Karlinsey, Allen C Mackey, Emily R Walker, Katherine E FrederickAbstract:A hybrid material comprised of beta-tricalcium phosphate (β-TCP) and sodium lauryl sulfate (SLS) was prepared using a mechanochemical process, examined using particle size analysis, IR spectroscopy, ^31P, ^23Na, and ^13C solid-state NMR spectroscopy, and calcium dissolution experiments, and probed for in vitro remineralization of subsurface enamel lesions. Our results suggest that while the ^31P environments of β-TCP remain unchanged during solid-state processing, there is noticeable shifting among the SLS ^23Na and ^13C environments. Therefore, given the structure of β-TCP, along with our IR examinations and calcium dissolution isotherms, SLS appears to interface strongly with the cation deficient C_3 symmetry site of the β-TCP hexagonal crystal lattice with probable emphasis placed on the underbonded CaO_3 polyhedra. To demonstrate the utility of the surface-active TCP material in dental applications, we combined the TCP–SLS with 5,000 ppm F (NaF) and evaluated the remineralization potential of subsurface enamel lesions via an in vitro remineralization/Demineralization pH cycling dental model. Using surface and longitudinal microhardness measurements, the TCP–SLS plus 5,000 ppm F system was found to significantly boost remineralization of subsurface enamel lesions, with microhardness values increasing up to 30% greater than fluoride alone.
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preparation characterization and in vitro efficacy of an acid modified β tcp material for dental hard tissue remineralization
Acta Biomaterialia, 2010Co-Authors: Robert L Karlinsey, Allen C Mackey, Emily R Walker, Katherine E FrederickAbstract:A blended material composed of beta-tricalcium phosphate (beta-TCP) and fumaric acid (FA) was prepared using a mechanochemical process. The structure and properties of the TCP-FA material was probed using particle size analysis, infrared, (31)P and (13)C solid-state nuclear magnetic resonance (NMR) spectroscopy, powder X-ray diffraction and calcium bioavailability. NMR studies showed that orthophosphate environments within beta-TCP remain largely unaffected in the presence of FA during mechanochemical processing; alternately, (13)C data indicated the carboxylic groups of FA are strongly affected during processing with beta-TCP. X-ray results reveal beta-TCP diffraction plane shifting with lattice contractions likely arising at the C(3) symmetry site. While milled beta-TCP (mTCP) produces a higher flux of bioavailable calcium relative to native beta-TCP, the mechanochemical conditioning of TCP-FA generates more than seven times the level of ionic calcium relative to mTCP. Collectively, the results from these studies indicate FA interfaces with calcium oxide polyhedra of the beta-TCP hexagonal crystal lattice, especially with the underbonded CaO(3) cluster manifested within the C(3) symmetry site of the beta-TCP motif. An in vitro remineralization/Demineralization pH cycling dental model was then used to assess the potential of the TCP-FA material in reversing early stage non-cavitated enamel lesions. Characterization of the remineralization via surface and longitudinal microhardness measurements demonstrated that the TCP-FA material provides statistically superior remineralization relative to milled and native beta-TCP.
Alberto Carlos Botazzo Delbem - One of the best experts on this subject based on the ideXlab platform.
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Resin-modified glass ionomer containing calcium glycerophosphate: physico-mechanical properties and enamel Demineralization
2019Co-Authors: Sâmia Sass Santos, Alberto Carlos Botazzo Delbem, João Carlos Silos Moraes, José Antônio Santos Souza, Lenara Queiroz Chaves Oliveira, Denise PedriniAbstract:Abstract Sources of calcium and phosphate have been added to dental restorative materials to improve their anticaries effect. Objective This study evaluated the effect of adding calcium glycerophosphate (CaGP) to resin-modified glass ionomer cement (RMGIC) on the physico-mechanical properties, ion release, and enamel Demineralization. Material and Methods: Specimens were fabricated for each experimental group: RMGIC without CaGP (Control), RMGIC with 1, 3 and 9% CaGP. To determine the release of fluoride (F), calcium (Ca) and phosphorus (P), six specimens were immersed in Demineralization and remineralization solutions for 15 days. In another experimental trial, the following physico-mechanical properties were evaluated at time intervals of 1 and 7 days after fabrication: compressive strength (n=12), diametral tensile strength (n=12), surface hardness of material (n=6) and the degree of conversion of monomers (n=8). To study enamel Demineralization, specimens (n=12) were attached to enamel blocks and submitted to pH-cycling. Subsequently, surface and cross-sectional hardness and the concentration of F, Ca and P in enamel were determined. Results The addition of CaGP to RMGIC led to higher mean release of F, Ca and P when compared with control (p0.439). The addition of 3% and 9% CaGP reduced mineral loss and increased F, Ca and P in the enamel when compared with control (p
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Effect of fluoride gels supplemented with sodium trimetaphosphate in reducing Demineralization
Clinical Oral Investigations, 2014Co-Authors: Marcelle Danelon, Eliana Mitsue Takeshita, Ligia Carla Peixoto, Kikue Takebayashi Sassaki, Alberto Carlos Botazzo DelbemAbstract:Objectives The objective of this study was to evaluate the in vitro effect of low-fluoride (F) gels supplemented with sodium trimetaphosphate (TMP) on enamel Demineralization. Materials and methods Bovine enamel blocks ( n = 160) were selected based on surface hardness (SH) and divided into eight treatment groups ( n = 20 per group): no F or TMP (placebo), 3 % TMP (3 %TMP), 5 % TMP (5 %TMP), 4,500 μg F/g (4,500), 4,500 μg F/g + 3 % TMP (4,500 3 %TMP), 4,500 μg F/g + 5 % TMP (4,500 5 %TMP), 9,000 μg F/g (9,000), and 12,300 μg F/g (acid gel). Blocks were subjected to Demineralization/remineralization cycling for 5 days. Subsequently, surface hardness (SH_1) and integrated loss of subsurface hardness (ΔKHN) were assessed, and the concentrations of loosely bound (CaF_2-like) and firmly bound (FA-like) formed and retained F were determined. Results The 4,500 5 %TMP and acid gel groups showed similar results and had the lowest mineral loss (SH_1 and ∆KHN). The acid gel group had the highest concentration of CaF_2-like F, but the formation and retention of FA-like F was greater in the 4,500 5 %TMP group than in the acid gel group ( p
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In situ evaluation of a low fluoride concentration gel with sodium trimetaphosphate in enamel remineralization.
American journal of dentistry, 2013Co-Authors: Marcelle Danelon, Eliana Mitsue Takeshita, Kikue Takebayashi Sassaki, Alberto Carlos Botazzo DelbemAbstract:PURPOSE To evaluate the capability of gels with low fluoride (F) concentration and supplemented with sodium trimetaphosphate (TMP) to promote in situ enamel remineralization. METHODS Bovine enamel blocks were selected on the basis of their surface hardness after Demineralization, and divided into five groups: gel without F or TMP (placebo); gel with 4,500 ppm F (4,500); gel with 4,500 ppm F + 5% TMP (4,500 5% TMP); gel with 9,000 ppm F (9,000) and gel with 12,300 ppm F (12,300). The study design was blind and cross-over: 12 subjects used palatal devices with four demineralized enamel blocks for 3 days, after topical fluoride application (TFA). Two blocks were removed immediately for analysis of the loosely bound fluoride (CaF2) and firmly bound fluoride (F) after TFA in enamel. In the remaining blocks, the percentage of surface hardness recovery (% SH), cross-sectional hardness (deltaKHN) and CaF2 and F were determined after remineralization. The results were subjected to ANOVA and Bonferroni tests (P 0.05). It was concluded that it is possible to promote enamel remineralization using gels with low fluoride concentration supplemented with TMP.
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Effect of iron on enamel Demineralization and remineralization in vitro
Archives of Oral Biology, 2011Co-Authors: K. M. R. P. Alves, Kikue Takebayashi Sassaki, Karina Simões Franco, Marília Afonso Rabelo Buzalaf, Alberto Carlos Botazzo DelbemAbstract:Objective To evaluate the effect of ferrous sulphate on enamel Demineralization and remineralization, using pH-cycling models. Design Fifty blocks were selected by their initial surface hardness and subjected to a pH-cycling Demineralization process. Artificially demineralized lesions were produced in 60 blocks; out of these blocks, the surface hardness of 50 blocks and the cross-sectional hardness of 10 blocks were determined. The 50 blocks were then subjected to a remineralization pH-cycling process. Treatments were carried out using ferrous sulphate solutions of different concentrations (0.333, 0.840, 18.0, and 70.0 μg Fe/mL) and a control group (deionized water). The final surface hardness (SH2) was determined, and the integrated subsurface hardness (ΔKHN) was calculated. The enamel blocks were analysed for fluoride, calcium, phosphorus, and iron. The obtained data were distributed heterogeneously and were analysed using the Kruskal–Wallis test (p
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ph cycling models for in vitro evaluation of the efficacy of fluoridated dentifrices for caries control strengths and limitations
Journal of Applied Oral Science, 2010Co-Authors: Marília Afonso Rabelo Buzalaf, Heitor Marques Honório, Angelica Reis Hannas, Ana Carolina Magalhaes, Daniela Rios, Alberto Carlos Botazzo DelbemAbstract:Despite a plethora of in situ studies and clinical trials evaluating the efficacy of fluoridated dentifrices on caries control, in vitro pH cycling models are still broadly used because they mimic the dynamics of mineral loss and gain involved in caries formation. This paper critically reviews the current literature on existing pH-cycling models for the in vitro evaluation of the efficacy of fluoridated dentifrices for caries control, focusing on their strengths and limitations. A search was undertaken in the MEDLINE electronic journal database using the keywords "pH-cycling", "Demineralization", "remineralization", "in vitro", "fluoride", "dentifrice". The primary outcome was the decrease of Demineralization or the increase of remineralization as measured by different methods (e.g.: transverse microradiography) or tooth fluoride uptake. Inclusion of studies, data extraction and quality assessment were undertaken independently and in duplicate by two members of the review team. Disagreements were solved by discussion and consensus or by a third party. One hundred and sixteen studies were included, of which 42 addressed specifically the comparison of dentifrices using different pH-cycling models. The other studies included meta-analysis or reviews, data about the effect of different fluoride sources on de-remineralization, different methods for analysis de-remineralization and chemical variables and characteristics of dental hard tissues that might have influence on de-remineralization processes. Generally, the studies presented ability to detect known results established by clinical trials, to demonstrate dose-related responses in the fluoride content of the dentifrices, and to provide repeatability and reproducibility between tests. In order to accomplish these features satisfactorily, it is mandatory to take into account the type of substrate and baseline artificial lesion, as well as the adequate response variables and statistical approaches to be used. This critical review of literature showed that the currently available pH-cycling models are appropriate to detect dose-response and pH-response of fluoride dentifrices, and to evaluate the impact of new active principles on the effect of fluoridated dentifrices, as well as their association with other anti-caries treatments.
Robert L Karlinsey - One of the best experts on this subject based on the ideXlab platform.
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Surfactant-modified β-TCP: structure, properties, and in vitro remineralization of subsurface enamel lesions
Journal of Materials Science: Materials in Medicine, 2010Co-Authors: Robert L Karlinsey, Allen C Mackey, Emily R Walker, Katherine E FrederickAbstract:A hybrid material comprised of beta-tricalcium phosphate (β-TCP) and sodium lauryl sulfate (SLS) was prepared using a mechanochemical process, examined using particle size analysis, IR spectroscopy, ^31P, ^23Na, and ^13C solid-state NMR spectroscopy, and calcium dissolution experiments, and probed for in vitro remineralization of subsurface enamel lesions. Our results suggest that while the ^31P environments of β-TCP remain unchanged during solid-state processing, there is noticeable shifting among the SLS ^23Na and ^13C environments. Therefore, given the structure of β-TCP, along with our IR examinations and calcium dissolution isotherms, SLS appears to interface strongly with the cation deficient C_3 symmetry site of the β-TCP hexagonal crystal lattice with probable emphasis placed on the underbonded CaO_3 polyhedra. To demonstrate the utility of the surface-active TCP material in dental applications, we combined the TCP–SLS with 5,000 ppm F (NaF) and evaluated the remineralization potential of subsurface enamel lesions via an in vitro remineralization/Demineralization pH cycling dental model. Using surface and longitudinal microhardness measurements, the TCP–SLS plus 5,000 ppm F system was found to significantly boost remineralization of subsurface enamel lesions, with microhardness values increasing up to 30% greater than fluoride alone.
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preparation characterization and in vitro efficacy of an acid modified β tcp material for dental hard tissue remineralization
Acta Biomaterialia, 2010Co-Authors: Robert L Karlinsey, Allen C Mackey, Emily R Walker, Katherine E FrederickAbstract:A blended material composed of beta-tricalcium phosphate (beta-TCP) and fumaric acid (FA) was prepared using a mechanochemical process. The structure and properties of the TCP-FA material was probed using particle size analysis, infrared, (31)P and (13)C solid-state nuclear magnetic resonance (NMR) spectroscopy, powder X-ray diffraction and calcium bioavailability. NMR studies showed that orthophosphate environments within beta-TCP remain largely unaffected in the presence of FA during mechanochemical processing; alternately, (13)C data indicated the carboxylic groups of FA are strongly affected during processing with beta-TCP. X-ray results reveal beta-TCP diffraction plane shifting with lattice contractions likely arising at the C(3) symmetry site. While milled beta-TCP (mTCP) produces a higher flux of bioavailable calcium relative to native beta-TCP, the mechanochemical conditioning of TCP-FA generates more than seven times the level of ionic calcium relative to mTCP. Collectively, the results from these studies indicate FA interfaces with calcium oxide polyhedra of the beta-TCP hexagonal crystal lattice, especially with the underbonded CaO(3) cluster manifested within the C(3) symmetry site of the beta-TCP motif. An in vitro remineralization/Demineralization pH cycling dental model was then used to assess the potential of the TCP-FA material in reversing early stage non-cavitated enamel lesions. Characterization of the remineralization via surface and longitudinal microhardness measurements demonstrated that the TCP-FA material provides statistically superior remineralization relative to milled and native beta-TCP.
Daniel Fried - One of the best experts on this subject based on the ideXlab platform.
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nondestructive assessment of early tooth Demineralization using cross polarization optical coherence tomography
IEEE Journal of Selected Topics in Quantum Electronics, 2010Co-Authors: Hobin Kang, J J Jiao, Chulsung Lee, Cynthia L Darling, Daniel FriedAbstract:New methods are needed for the nondestructive measurement of tooth Demineralization and remineralization to monitor the progression of incipient caries lesions (tooth decay) for effective nonsurgical intervention and to evaluate the performance of anticaries treatments such as chemical treatments or laser irradiation. Studies have shown that optical coherence tomography (OCT) has great potential to fulfill this role since it can be used to measure the depth and severity of early lesions with an axial resolution exceeding 10 μm, it is easy to apply in vivo and it can be used to image the convoluted topography of tooth occlusal surfaces. In this paper, a review of the use of polarization-sensitive-OCT for the measurement of tooth Demineralization is provided along with some recent results regarding improved methods for the detection of caries lesions in the earliest stages of development. Automated methods of analysis were used to measure the depth and severity of demineralized bovine enamel produced using simulated caries models that emulate Demineralization in the mouth. Significant differences in the depth and integrated reflectivity from the lesions were detected after only a few hours of Demineralization. These results demonstrate that cross-polarization-OCT is ideally suited for the nondestructive assessment of early Demineralization.
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Imaging early Demineralization with PS-OCT.
Bios, 2010Co-Authors: Hobin Kang, J J Jiao, Chulsung Lee, Cynthia L Darling, Daniel FriedAbstract:New methods are needed for the nondestructive measurement of tooth Demineralization and remineralization to monitor the progression of incipient caries lesions (tooth decay) for effective nonsurgical intervention and to evaluate the performance of anti-caries treatments such as chemical treatments or laser irradiation. Studies have shown that optical coherence tomography (OCT) has great potential to fulfill this role since it can be used to measure the depth and severity of early lesions with an axial resolution exceeding 10-μm, it is easy to apply in vivo and it can be used to image the convoluted topography of tooth occlusal surfaces. In this paper we attempt to determine the earliest stage at which we can detect significant differences in lesion severity. Automated methods of analysis were used to measure the depth and severity of demineralized bovine enamel produced using a simulated caries model that emulates Demineralization in the mouth. Significant differences in the depth and integrated reflectivity from the lesions were detected after only a few hours of Demineralization. These results demonstrate that cross polarization OCT is ideally suited for the nondestructive assessment of early Demineralization.
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automated analysis of lesion depth and integrated reflectivity in ps oct scans of tooth Demineralization
Lasers in Surgery and Medicine, 2010Co-Authors: Cynthia L Darling, Daniel FriedAbstract:Background and Objectives Several studies have demonstrated that polarization sensitive optical coherence tomography (PS-OCT) can be used to nondestructively measure the severity of subsurface Demineralization in enamel and dentin, track lesion progression over time and measure remineralization. The purpose of this study was to develop methods for the automated assessment of the depth and severity of Demineralization in PS-OCT scans. Materials and Methods Subsurface caries-like lesions of increasing depth and severity were produced in adjoining windows on 10 bovine enamel samples via exposure to Demineralization for periods of 1–4 days. PS-OCT scans were acquired for each sample and analyzed using various methods to calculate the lesion depth and severity. Edge detection algorithms were most successful for measurement of the lesion depth for improved assessment of lesion severity. Results Edge-finding algorithms were able to detect significant differences (P<0.05) in the lesion depth and severity between each of the periods of Demineralization and sound enamel. The lesion depth and mineral loss were also measured with polarized light microscopy and transverse microradiography after sectioning the teeth for comparison. Conclusions This study demonstrates that the depth and severity of early lesions can be calculated automatically for rapid analysis of PS-OCT images. Lasers Surg. Med. 42:62–68, 2010. © 2010 Wiley-Liss, Inc.
Allen C Mackey - One of the best experts on this subject based on the ideXlab platform.
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Surfactant-modified β-TCP: structure, properties, and in vitro remineralization of subsurface enamel lesions
Journal of Materials Science: Materials in Medicine, 2010Co-Authors: Robert L Karlinsey, Allen C Mackey, Emily R Walker, Katherine E FrederickAbstract:A hybrid material comprised of beta-tricalcium phosphate (β-TCP) and sodium lauryl sulfate (SLS) was prepared using a mechanochemical process, examined using particle size analysis, IR spectroscopy, ^31P, ^23Na, and ^13C solid-state NMR spectroscopy, and calcium dissolution experiments, and probed for in vitro remineralization of subsurface enamel lesions. Our results suggest that while the ^31P environments of β-TCP remain unchanged during solid-state processing, there is noticeable shifting among the SLS ^23Na and ^13C environments. Therefore, given the structure of β-TCP, along with our IR examinations and calcium dissolution isotherms, SLS appears to interface strongly with the cation deficient C_3 symmetry site of the β-TCP hexagonal crystal lattice with probable emphasis placed on the underbonded CaO_3 polyhedra. To demonstrate the utility of the surface-active TCP material in dental applications, we combined the TCP–SLS with 5,000 ppm F (NaF) and evaluated the remineralization potential of subsurface enamel lesions via an in vitro remineralization/Demineralization pH cycling dental model. Using surface and longitudinal microhardness measurements, the TCP–SLS plus 5,000 ppm F system was found to significantly boost remineralization of subsurface enamel lesions, with microhardness values increasing up to 30% greater than fluoride alone.
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preparation characterization and in vitro efficacy of an acid modified β tcp material for dental hard tissue remineralization
Acta Biomaterialia, 2010Co-Authors: Robert L Karlinsey, Allen C Mackey, Emily R Walker, Katherine E FrederickAbstract:A blended material composed of beta-tricalcium phosphate (beta-TCP) and fumaric acid (FA) was prepared using a mechanochemical process. The structure and properties of the TCP-FA material was probed using particle size analysis, infrared, (31)P and (13)C solid-state nuclear magnetic resonance (NMR) spectroscopy, powder X-ray diffraction and calcium bioavailability. NMR studies showed that orthophosphate environments within beta-TCP remain largely unaffected in the presence of FA during mechanochemical processing; alternately, (13)C data indicated the carboxylic groups of FA are strongly affected during processing with beta-TCP. X-ray results reveal beta-TCP diffraction plane shifting with lattice contractions likely arising at the C(3) symmetry site. While milled beta-TCP (mTCP) produces a higher flux of bioavailable calcium relative to native beta-TCP, the mechanochemical conditioning of TCP-FA generates more than seven times the level of ionic calcium relative to mTCP. Collectively, the results from these studies indicate FA interfaces with calcium oxide polyhedra of the beta-TCP hexagonal crystal lattice, especially with the underbonded CaO(3) cluster manifested within the C(3) symmetry site of the beta-TCP motif. An in vitro remineralization/Demineralization pH cycling dental model was then used to assess the potential of the TCP-FA material in reversing early stage non-cavitated enamel lesions. Characterization of the remineralization via surface and longitudinal microhardness measurements demonstrated that the TCP-FA material provides statistically superior remineralization relative to milled and native beta-TCP.
