Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
1.
Am J Orthod Dentofacial Orthop ; 163(6): 835-842, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36720655

RESUMO

INTRODUCTION: The objective of this study was to determine the prevalence of white spot lesions (WSL) in orthodontic patients in an academic setting. Specific aims include using a novel combination to measure plaque accumulation (PA) and detect the association between WSL and PA and the associations between multiple independent variables. METHODS: Cross-sectional data were collected on 111 patients. To enhance standardization, a combination of plaque-disclosing agents and standardized intraoral photographs was used to analyze plaque index (PI) and WSL for all teeth except molars. Factors including time in fixed appliances (FA), number of teeth, location of the lesions, and demographic information were reported. A multiple linear regression model was used to detect associations between the PI and WSL and the independent variables (P <0.05). RESULTS: Approximately 79.3% of participants had at least one WSL, with a mean of 4 affected teeth per patient. A significant association was found between time in FA and the more severe PI reporting (P <0.001). There was no significant association between WSL and PI or the other variables. WSL was greater in the maxilla than in the mandible. PI was greater on the left than on the right side. Interexaminer reliability was assessed for PI and WSL (κ = 0.93 and 0.92). CONCLUSIONS: The prevalence of WSL for orthodontic patients treated at this institution was greater than previously reported in the literature. In addition, the severity of PI was associated with increased time in FAs. Combining the proposed method of reporting PA facilitates standardization, calibration, and documentation in an academic environment.


Assuntos
Cárie Dentária , Placa Dentária , Humanos , Cárie Dentária/epidemiologia , Placa Dentária/epidemiologia , Prevalência , Índice Periodontal , Estudos Transversais , Masculino , Feminino , Criança , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade
2.
Environ Sci Technol ; 56(12): 7810-7819, 2022 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-35537062

RESUMO

The use of low-density polyethylene (PE) sheets as equilibrium passive soil gas samplers to quantify volatile organic compounds (VOCs) such as benzene, toluene, ethylbenzene, and xylenes, and chlorinated solvents (e.g., trichloroethene and tetrachloroethene) in unsaturated subsurface environments was evaluated via modeling and benchtop testing. Two methods were devised to quantify such VOCs in PE. Key chemical properties, including PE-water (KPEw) and PE-air (KPEa) partition coefficients and diffusivities in the PE (Dpe), were determined. These KPEw, KPEa, and Dpe values were consistent with extrapolations of data based on larger compounds. Using these parameter values, field equilibration times of less than 1 day were estimated for such VOCs when using 70-100 µm thick PE sheets. Further, benchtop batch tests carried out in jars filled with VOC-contaminated soils, after 1 or 2 days, showed concentrations in soil air deduced from PE that were consistent with concentrations deduced by analyzing either water or headspace gases recovered from the same tests. Thus, PE-based measurements may overcome inaccuracies from using total soil concentrations and equilibrium partitioning models that may overestimate vapor phase concentrations up to 2 orders of magnitude.


Assuntos
Polietileno , Compostos Orgânicos Voláteis , Monitoramento Ambiental/métodos , Gases , Polietileno/química , Solo , Compostos Orgânicos Voláteis/química , Água/química
3.
J Sep Sci ; 38(17): 2968-74, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26075936

RESUMO

Three mixed-mode high-performance liquid chromatography columns packed with superficially porous carbon/nanodiamond/amine-polymer particles were used to separate mixtures of cannabinoids. Columns evaluated included: (i) reversed phase (C18 ), weak anion exchange, 4.6 × 33 mm, 3.6 µm, and 4.6 × 100 mm, 3.6 µm, (ii) reversed phase, strong anion exchange (quaternary amine), 4.6×33 mm, 3.6 µm, and (iii) hydrophilic interaction liquid chromatography, 4.6 × 150 mm, 3.6 µm. Different selectivities were achieved under various mobile phase and stationary phase conditions. Efficiencies and peak capacities were as high as 54 000 N/m and 56, respectively. The reversed phase mixed-mode column (C18 ) retained tetrahydrocannabinolic acid strongly under acidic conditions and weakly under basic conditions. Tetrahydrocannabinolic acid was retained strongly on the reversed phase, strong anion exchange mixed-mode column under basic polar organic mobile phase conditions. The hydrophilic interaction liquid chromatography column retained polar cannabinoids better than the (more) neutral ones under basic conditions. A longer reversed phase (C18 ) mixed-mode column (4.6 × 100 mm) showed better resolution for analytes (and a contaminant) than a shorter column. Fast separations were achieved in less than 5 min and sometimes 2 min. A real world sample (bubble hash extract) was also analyzed by gradient elution.


Assuntos
Canabinoides/análise , Aminas/química , Canabinoides/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Cromatografia de Fase Reversa/métodos , Dronabinol/análise , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Nanodiamantes/química , Nanopartículas/química , Nanotecnologia/métodos , Compostos Orgânicos/química , Polímeros/química , Porosidade , Detecção do Abuso de Substâncias/métodos
4.
Dent J (Basel) ; 11(3)2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36975578

RESUMO

Complete denture fabrication requires multiple clinical and laboratory steps. One of the most critical clinical steps is establishing an anatomical occlusal plane based on hard and soft tissue references. The aim of this study was to determine whether age or gender affects the level of the Ala-Tragus plane to establish which reference point on the Tragus should be used when fabricating the occlusal plane in edentulous patients. Clinical photographs and lateral cephalometric radiographs with complete dentitions were taken from 58 volunteers at the DMD clinic at the University of Kentucky. Each photograph was superimposed over its corresponding cephalometric image. An analysis was conducted to establish the angle of the occlusal plane relative to the Ala-Tragus landmarks; this data was then grouped according to age and gender. The analysis shows that age and gender did not significantly affect where the Camper's plane should be approximated for complete denture treatment. However, it was found that the most parallel line to the occlusal plane was Ala's inferior border to the 'Tragus's inferior border. It should be noted that the volunteers' skeletal classification was significantly related to a Cl III malocclusion tendency. Still, with this new information, functionality and esthetics can be more adequately addressed for patients undergoing complete denture treatment. Given our results, we suggest redefining the 'Camper's plane with a line extending from 'Ala's inferior border to the 'Tragus's inferior border instead of the superior border. Further consideration should be taken if the patient is a skeletal CL III malocclusion.

5.
J Periodontol ; 89(7): 858-866, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29676776

RESUMO

BACKGROUND: Neuropeptides (NPs) are innate pivotal regulators of the immunoinflammatory response. Nevertheless, their role in the pathogenesis of periodontal disease remains unknown. Changes in gene expression of 10 NPs and 16 NP receptors (NPRs) coincident with the initiation, progression, and resolution of periodontitis were determined. METHODS: The ligature-induced periodontitis model was used in rhesus monkeys (n = 18). Gingival tissue samples were taken at baseline (preligatures), at 2 weeks and at 1 month (initiation), and at 3 months (progression) postligation. Ligatures were removed and samples taken 2 months later (resolution). Total RNA was isolated from tissues and NP/NPR gene expression microarray analysis was performed. Gene expression changes were validated by quantitative polymerase chain reaction and immunohistochemistry. RESULTS: Unexpectedly, the expression of pro-inflammatory NPs/NPRs did not change during periodontitis or with resolution. However, increased expression of the anti-inflammatory NPs adrenomedullin (ADM) and galanin (GAL), and the NPRs calcitonin receptor-like (CALCRL) and receptor activity-modifying protein-2 and -3 (RAMP2 and RAMP3) were observed during initiation and progression of disease. The expression of the same NPs/NPRs exhibited a significant positive correlation with both molecular (interleukin-1ß, matrix mettaloproteinase-9, and receptor activator of nuclear factor-kappa B ligand) and clinical measures of gingival inflammation and tissue destruction. CONCLUSION: Initiation and progression of periodontitis involve significant overexpression of ADM, GAL, CALCRL, RAMP2, and RAMP3. These anti-inflammatory NPs/NPRs could play a role in the unresolved infection and inflammation that normally drives tissue destruction in periodontitis. Both ADM and GAL potentially are new candidates to consider as biomolecules associated with periodontal disease activity.


Assuntos
Mucosa Bucal , Neuropeptídeos , Animais , Primatas , Proteína 3 Modificadora da Atividade de Receptores , Receptores da Calcitonina
6.
J Chromatogr A ; 1217(49): 7621-9, 2010 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-21047639

RESUMO

We describe direct polymer attachment to hydrogen and deuterium-terminated diamond (HTD and DTD) surfaces using a radical initiator (di-tert-amyl peroxide, DTAP), a reactive monomer (styrene) and a crosslinking agent (divinylbenzene, DVB) to create polystyrene encapsulated diamond. Chemisorbed polystyrene is sulfonated with sulfuric acid in acetic acid. Surface changes were followed by X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and diffuse reflectance Fourier transform infrared spectroscopy (DRIFT). Finally, both polystyrene-modified DTD and sulfonated styrene-modified DTD were used in solid phase extraction (SPE). Percent recovery and column capacity were investigated for both phenyl (polystyrene) and sulfonic acid treated polystyrene SPE columns. These diamond-based SPE supports are stable under basic conditions, which is not the case for silica-based SPE supports.


Assuntos
Resinas de Troca de Cátion/química , Deutério/química , Diamante/química , Poliestirenos/química , Extração em Fase Sólida/métodos , 1-Naftilamina/química , Adsorção , Cromatografia por Troca Iônica , Reagentes de Ligações Cruzadas , Hidrogênio/química , Peróxidos/química , Espectroscopia Fotoeletrônica , Espectrometria de Massas por Ionização por Electrospray , Ácidos Sulfônicos/química , Propriedades de Superfície , Compostos de Vinila/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA