Higher Fluorosis Severity Makes Enamel Less Resistant to Demineralization

2016 ◽  
Vol 50 (4) ◽  
pp. 407-413 ◽  
Author(s):  
Lina María Marín ◽  
Jaime Aparecido Cury ◽  
Livia Maria Andaló Tenuta ◽  
Jaime Eduardo Castellanos ◽  
Stefania Martignon
Keyword(s):  
Concentration Gradient ◽  
Inorganic Phosphate ◽  
Fluoride Concentration ◽  
Statistical Analyses ◽  
The Other ◽  
Tooth Crown ◽  
Third Molars ◽  
Cross Sectional ◽  
Acid Diffusion ◽  
Ph Cycling

Fluorotic teeth could either be more resistant or more susceptible to the caries process than sound ones due to their higher enamel fluoride concentration and higher porosity (subsurface hypomineralization), respectively; however, there is no consensus on this subject. In this study, a total of 49 human unerupted third molars presenting Thylstrup and Fejerskov (TF) fluorosis scores 0-4 were used. Two enamel slabs were obtained from each tooth. The rest of the tooth crown was powdered, and the enamel was separated from the dentine. In purified powdered enamel, the calcium (Ca), inorganic phosphate (Pi), and fluoride (F) concentrations were determined. The F concentration gradient throughout the enamel and in the enamel volume was determined in one slab. The other enamel slab was isolated with acid-resistant varnish, subjecting the exposed enamel surface half to a pH-cycling model to evaluate its demineralization resistance and to calculate the demineralization area. The nonexposed surface was used to determine the natural hypomineralization area found in fluorotic enamel and normalize the demineralization data. The hypomineralization and demineralization areas were assessed by cross-sectional microhardness. For statistical analyses, the data for TF1 and 2, and for TF3 and 4 were pooled. Concentrations of powered enamel Ca and Pi were not significantly different (p > 0.05) among groups TF0, TF1-2 and TF3-4, but a higher F concentration was found in fluorotic enamel (p < 0.05). Highly fluorotic teeth (TF3-4) presented a greater hypomineralization subsurface area and demonstrated lower demineralization resistance than sound enamel (p < 0.05). The findings suggest that a higher severity of fluorosis makes enamel less resistant to the caries process due to its greater subsurface mineral area exposed to demineralization and deeper acid diffusion through the enamel.

scholarly journals Fluoride Dentifrice Overcomes the Lower Resistance of Fluorotic Enamel to Demineralization

2019 ◽  
Vol 53 (5) ◽  
pp. 567-575
Author(s):  
Luma Fabiane Almeida ◽  
Lina María Marín ◽  
Esperanza Angeles Martínez-Mier ◽  
Jaime Aparecido Cury
Keyword(s):  
Statistical Analysis ◽  
Fluoride Concentration ◽  
The Other ◽  
Human Teeth ◽  
Cross Sectional ◽  
Low Resistance ◽  
Lower Resistance ◽  
Enamel Mineralization ◽  
Ph Cycling ◽  
Fluoride Dentifrice

We evaluated if the low resistance of fluorotic enamel to demineralization could be overcome by fluoride dentifrice (FD) treatment. Paired enamel slabs of sound and fluorotic enamel (n = 20/group) from human teeth presenting Thylstrup and Fejerskov index (TF) scores from 0 to 4 were obtained. Half of the anatomic surface of the enamel slabs was isolated and used as a control (baseline) regarding enamel mineralization and fluoride concentration. The slabs were submitted to a pH-cycling model simulating a high cariogenic challenge, and 2×/day they were treated with placebo dentifrice (PD) or FD (1,100 µg F/g, as NaF). After 10 days, the slabs were cut into two halves. Enamel demineralization was evaluated by cross-sectional microhardness in one half, and the fluoride formed (FF) concentration was determined in the other half. For statistical analysis, the data on net demineralization area (ΔΔS) and FF (µg F/g) were grouped into TF0, TF1–2, and TF3–4, and analyzed by two-way ANOVA followed by Tukey’s test (α = 5%). The factors studied were TF (0, 1–2, and 3–4) and dentifrice treatment (PD or FD). The effect of the factors was statistically significant for ΔΔS and FF (p < 0.05). In the PD group, the following pattern for ΔΔS was observed: TF3–4 > TF1–2 > TF0 (p < 0.05); however, the groups did not differ (p > 0.05) when FD was used. Regarding FF, the groups treated with PD did not differ (p > 0.05), but the greatest (p < 0.05) FF concentration was found in group TF3–4 treated with FD. These findings suggest that the higher susceptibility of fluorotic enamel to demineralization lesions is decreased by the use of FD.

scholarly journals In vitro comparison of the cariostatic effect between topical application of fluoride gels and fluoride toothpaste

2004 ◽  
Vol 12 (2) ◽  
pp. 121-126 ◽  
Author(s):  
Alberto Carlos Botazzo Delbem ◽  
Fernanda Lourenção Brighenti ◽  
Ana Elisa de Mello Vieira ◽  
Jaime Aparecido Cury
Keyword(s):  
Fluoride Concentration ◽  
Preventive Measure ◽  
Progression Rate ◽  
Surface Microhardness ◽  
Human Teeth ◽  
Cross Sectional ◽  
Fluoride Toothpaste ◽  
Fluoride Uptake ◽  
Ph Cycling

The aim of this study was to compare the effect of topical fluoride products [acidulated phosphate fluoride (APF) or neutral gel (NF) x fluoride toothpaste (MFP)], in respect to fluoride uptake and anticariogenic action. One hundred and twenty five blocks of human teeth, sorted in 5 groups according to the treatment, were submitted to pH cycling for ten days. The parameters analyzed were: fluoride uptake before and after pH cycling and surface (SMH) and cross-sectional (CSMH) microhardness of the enamel blocks. The results of fluoride concentration in enamel after the pH cycling showed an enhancement of fluoride uptake for all groups compared to sound control. No significant differences between APF and MFP were observed for surface microhardness, percentage change of surface microhardness and mineral loss. The volume percent mineral obtained from cross-sectional microhardness demonstrated that APF has a different lesion progression rate regarding subsurface carious lesion. The results suggest that professionally applied fluoride gel or frequent fluoride application in low concentration is a positive preventive measure for the control of dental caries.

scholarly journals Resistance against Erosive Challenge of Dental Enamel Treated with 1,450-PPM Fluoride Toothpastes Containing Different Biomimetic Compounds

2021 ◽  
Author(s):  
Nayanna L. S. Fernandes ◽  
L. da Cunha Juliellen ◽  
F. B. de Oliveira Andressa ◽  
H. P. Paulo D’Alpino ◽  
C. Fábio Sampaio
Keyword(s):  
Dental Enamel ◽  
In Vitro Study ◽  
The Other ◽  
Mineral Layer ◽  
Cross Sectional ◽  
X Ray ◽  
Weight Percentage ◽  
Elemental Analyses ◽  
Ph Cycling

Abstract Objectives This in vitro study aimed to characterize the superficial and subsurface morphology of dental enamel treated with fluoridated gels containing different biomimetic compounds after erosive challenge. Materials and Methods Bovine incisor teeth were sectioned to obtain enamel blocks (4 mm × 4 mm × 6 mm; n = 5) that were demineralized to create an artificial caries lesion and treated by pH cycling interspersed with exposure to fluoridated toothpaste slurries under agitation. During pH cycling (demineralization and remineralization for 2 and 22 hours, respectively) for 6 days, the enamel blocks were exposed to toothpaste slurries under agitation with one of the dental gels: Regenerate Enamel Science (NR-5 technology), Daily Regenerator Dental Clean (REFIX technology), and Sensodyne Repair & Protect (Novamin technology). The enamel blocks were subjected to an erosive challenge, immersed in 50% citric acid for 2 minutes, and then washed with plenty of distilled water. The surface and cross-sectional micromorphology were assessed using scanning electron microscope (SEM). The elemental analyses (weight percentage) were determined with an energy-dispersive X-ray spectroscopy (EDS). Results Enamel treated with the product containing REFIX technology presented a smoother surface morphology compared to the other treatments. The higher resistance to the erosive challenge can be attributed to a silicon-enriched mineral layer formed on the enamel induced by the REFIX-based toothpaste. This was not observed in the specimens treated with the other technology-containing toothpastes. Conclusion The REFIX technology seemed to be the most promising compared to the Novamin and NR-5 technologies. In addition to forming a surface mineralized layer, the enamel treated with REFIX technology associated with the pH cycling resisted a subsequent erosive challenge.

scholarly journals Effect of Fluoride Concentration on Reduction of Enamel Demineralization According to the Cariogenic Challenge

2016 ◽  
Vol 27 (4) ◽  
pp. 393-398 ◽  
Author(s):  
Mayara dos Santos Noronha ◽  
Dayse Andrade Romão ◽  
Jaime Aparecido Cury ◽  
Cínthia Pereira Machado Tabchoury
Keyword(s):  
Fluoride Concentration ◽  
Caries Risk ◽  
Cross Sectional ◽  
Treatment Groups ◽  
Enamel Demineralization ◽  
Ph Cycling

Abstract Fluoride present in toothpaste at 1,100 µg/g is considered effective on caries control. However, under high cariogenic challenge due to increasing sugar exposure, higher fluoride concentration (5,000 µg/g) could be necessary to compensate the unbalance on caries process. This was tested in a pH-cycling regimen, which evaluated the effect of fluoride concentration relative to toothpaste on reduction of enamel demineralization under conditions of two levels of cariogenic challenge. Enamel slabs (n=20) were subjected to two pH-cycling regimens, simulating 8x and 16x/day sugar exposure and were treated with solutions containing: 0 (no fluoride), 275 or 1,250 µg F/mL, resulting in 6 treatment groups: 4-h/0-F; 8-h/0-F; 4-h/275-F; 8-h/275-F; 4-h/1,250-F and 8-h/1,250-F. The 275 and 1,250 µg F/mL concentrations simulate mouth salivary dilution when 1,100 and 5,000 µg/g toothpastes are used. Enamel demineralization was assessed by surface (%SHL) and cross-sectional hardness. Fluoride taken up by enamel was also evaluated. Data were analyzed by ANOVA one-way and Tukey's test. The treatment with 1,250 µg F/mL significantly reduced %SHL compared with 275 µg F/mL (p<0.05), irrespective the level of cariogenic challenge (4-h/1,250-F vs. 4-h/275-F and 8-h/1,250-F vs 8-h/275-F comparisons, respectively). These data were supported by fluoride concentration found in enamel. These findings suggest that higher fluoride concentrations could partly compensate the greater caries risk under higher cariogenic challenge due to increasing sugar exposure.

HISTOPATHOLOGY OF THE PIGMENTED TUMORAL-LIKE LESIONS OF THE SKIN AT HUE HOSPITAL OF MEDICINE AND PHARMACY UNIVERSITY

2018 ◽  
Vol 8 (4) ◽  
pp. 65-69
Author(s):  
Mao Nguyen Van ◽  
Dong Tran Nam
Keyword(s):  
Key Words ◽  
Definitive Diagnosis ◽  
The Other ◽  
Cell Tumour ◽  
Cross Sectional ◽  
Skin Tumour ◽  
Clinical Appearance ◽  
The Face ◽  
The Common ◽  
Difficult Cases

Background: Pigmented tumour of the skin is one of the common tumour in human including the benign pigmented tumours (more common) called Nevi tumours and the malignant one called melanoma which was less frequent but the most poor in prognosis. In addition, the others not belonging to these group had the same clinical appearance, so the application of histopathology and immunohistochemistry for the definitive diagnosis was indespensible. Objectives: 1. To describe the macroscopic features of the pigmented tumoral-like lesions; 2. To classify the histopathologic types of the pigmented cell tumours and the other pigmented tumours of the skin. Materials and Method: Cross-sectional research on 55 patients diagnosed as pigmented tumoral lesions by clinician, then all definitively diagnosed by histopathology combining the immunohistochemistry in difficult cases. Results: There was no difference in gender, the disease was discovered most common in adult, especially with the age over 51 years old (58.1%). the most region located was in the face accounting for 60%, following the trunk and limbs (14.6%, 12.8% respectively). All 3 malignant melanomas happened in foot. The most common color of the lesions was black (65.4%), the other ones were rose, grey and blue. Histopathology and immunohisthochemistry showed that the true pigmented cell tumours were 52.6% encompassing benign ones (Nevi tumour) (41.8%), melanoma (5.4%) and lentigo (5.4%). 47.4% was not the true pigmented cell tumour including pigmented basocellular carcinoma (36.4%) and the others less common as histiofibromas, acanthoma and papilloma. Conclusion: the pigmented tumoral-like lesions of the skin could be the true pigmented cell tumours and the others, so the application of the histopathology and the immunohistochemistry after the clinical discovery helps to determine and classify the disease definitely and for the best orientation of treatment as well. Key words: skin tumour, benign pigmented tumour (Nevi), malignant pigmented tumour (melanoma), pigmented basocellular carcinoma

EXPRESSION OF SOME IMMUNOLOGIC MARKERS FOR THE DIAGNOSIS OF SUSPECTED LYMPHOID LESIONS OF LYMPHOMA

2018 ◽  
Vol 8 (4) ◽  
pp. 28-33
Author(s):  
Mao Nguyen Van ◽  
Thao Le Thi Thu
Keyword(s):  
Correct Diagnosis ◽  
Tumour Cells ◽  
The Body ◽  
The Other ◽  
Cervical Region ◽  
Cross Sectional ◽  
Immunologic Markers ◽  
Microscopic Features ◽  
Poor Differentiation ◽  
Benign Tumours

Background: In practice it was difficult or impossible to have a correct diagnosis for the lymphoid proliferation lesions based on only H.E standard histopathology. In addition to histopathology, the application of immunohistochemistry was indispensable for the definitive diagnosis of the malignant or benign tumours and the origin of the tumour cells as well. Objectives: 1. To describe the gross and microscopic features of the suspected lesions of lymphoma; 2. To asses the expression of some immunologic markers for the diagnosis and classification of the suspected lesions of lymphoma. Materials and Method: Cross-sectional research on 81 patients diagnosed by histopathology as lymphomas or suspected lesions of lymphoma, following with immunohistopathology staining of 6 main markers including LCA, CD3, CD20, Bcl2, CD30 and AE1/3. Results: The most site was lymph node 58.1% which appeared at cervical region 72.3%, then the stomach 14.9% and small intestine 12.4%. The other sites in the body were met with lower frequency. Histopathologically, the most type of the lesions was atypical hyperplasia of the lymphoid tissue suspecting the lymphomas 49.4%, lymphomas 34.5%, the other diagnoses were lower including inflammation, poor differentiation carcinoam not excluding the lymphomas, lymphomas differentiating with poor differentiation carcinomas. Immunohistochemistry showed that, LCA, CD3, CD20, Bcl2, CD30 and AE1/3 were all positive depending on such type of tumours. The real lymphomas were 48/81 cases (59.3%), benign ones 35.8% and poor differentiated carcinomas 4.9%. Conclusion: Immunohistochemistry with 6 markers could help to diagnose correctly as benign or malignant lesions, classify and determine the origin of the tumour cells as lymphocytes or epithelial cells diagnosed by histopathology as lymphomas or suspected lesions of lymphomas. Key words: histopathology, immunohistochemistry, lymphomas, poor differentiated carcinomas, hyperplasia, atypicality

Human density, economic level and frequency of canine helminths in Buenos Aires

2021 ◽  
Vol 95 ◽  
Author(s):  
D. Rubel ◽  
N. Flaibani
Keyword(s):  
Linear Models ◽  
Buenos Aires ◽  
Toxocara Canis ◽  
The Other ◽  
Green Spaces ◽  
Cross Sectional ◽  
Independent Variables ◽  
Economic Level ◽  
Faecal Samples ◽  
Human Density

Abstract The aim of this study was to explore through cross-sectional study the variation in the prevalence of parasitic helminths in canine faeces collected from green spaces of Buenos Aires according to the human density (HD) and economic level (EL) in the surroundings. HD and EL were considered as independent variables with three categories each. Twenty public squares (one hectare of surface) were randomly selected for each existing combination of the two independent variables. Ten random samples of fresh canine faeces were obtained in each square and analysed for helminths by the sedimentation and flotation techniques. The prevalence for each of the species was analysed using generalized linear models (GLM). The prevalence was modelled with a binomial error distribution and a logit link function. Helminth eggs were detected in 45 out of the 200 (22.5%) faecal samples collected and in 18 of the 20 green spaces sampled. The species observed were Ancylostoma caninum (13% of samples), Trichuris vulpis (8%) and Toxocara canis (4.5%). The GLM indicated that the prevalence of A. caninum in the slum areas (very high HD and very low EL) was higher than that in the other areas studied. However, the HD seemed to contribute more than the EL to the variations in the prevalence of A. caninum in faecal samples. The GLM showed no differences in the prevalence of the other parasite species for the different levels of the independent variables.

scholarly journals Quality of Life of Brazilian Vegetarians Measured by the WHOQOL-BREF: Influence of Type of Diet, Motivation and Sociodemographic Data

Nutrients ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 2648
Author(s):  
Shila Minari Hargreaves ◽  
Eduardo Yoshio Nakano ◽  
Heesup Han ◽  
António Raposo ◽  
Antonio Ariza-Montes ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Online Survey ◽  
Well Being ◽  
Vegetarian Diet ◽  
The Other ◽  
Average Score ◽  
Cross Sectional ◽  
Domain 3 ◽  
Domain 4

This study aimed to evaluate the general quality of life (QoL) of Brazilian vegetarians. A cross-sectional study was conducted with Brazilian vegetarian adults (18 years old and above). Individuals were recruited to participate in a nationwide online survey that comprised the WHOQOL-BREF as well as sociodemographic and characterization questions related to vegetarianism. The WHOQOL-BREF is composed of 24 items which are divided into four domains (domain 1: physical health; domain 2: psychological well-being; domain 3: social relationships; and domain 4: environment), plus two general items which were analyzed separately, totaling 26 items. The answers from the questionnaire were converted into scores with a 0–100 scale range, with separate analyses for each domain. Results were compared among groups based on the different characteristics of the vegetarian population. A total of 4375 individuals completed the survey. General average score results were 74.67 (domain 1), 66.71 (domain 2), 63.66 (domain 3) and 65.76 (domain 4). Vegans showed better scores when compared to the other vegetarians, except in domain four, where the statistical difference was observed only for semi-vegetarians (lower score). Individuals adopting a vegetarian diet for longer (>1 year) showed better results for domains one and two, with no difference for the other domains. Having close people also adopting a vegetarian diet positively influenced the results for all domains. On the other hand, it was not possible to distinguish any clear influence of the motivation for adopting a vegetarian diet on the scores’ results. Adopting a vegetarian diet does not have detrimental effects on one’s QoL. In fact, the more plant-based the diet, and the longer it was adopted, the better the results were.

scholarly journals Assessment of Inorganic Phosphate Intake by the Measurement of the Phosphate/Urea Nitrogen Ratio in Urine

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 292
Author(s):  
María Victoria Pendón-Ruiz de Mier ◽  
Noemí Vergara ◽  
Cristian Rodelo-Haad ◽  
María Dolores López-Zamorano ◽  
Cristina Membrives-González ◽  
...  
Keyword(s):  
Inorganic Phosphate ◽  
Daily Intake ◽  
Cross Sectional Study ◽  
Normal Serum ◽  
Dietary Recommendations ◽  
Clinical Practices ◽  
Cross Sectional ◽  
Urea Nitrogen ◽  
Inorganic P ◽  
Nitrogen Ratio

In chronic kidney disease (CKD) patients, it would be desirable to reduce the intake of inorganic phosphate (P) rather than limit the intake of P contained in proteins. Urinary excretion of P should reflect intestinal absorption of P(inorganic plus protein-derived). The aim of the present study is to determine whether the ratio of urinary P to urinary urea nitrogen (P/UUN ratio) helps identify patients with a high intake of inorganic P.A cross-sectional study was performed in 71 patients affected by metabolic syndrome with CKD (stages 2–3) with normal serum P concentration. A 3-day dietary survey was performed to estimate the average daily amount and the source of P ingested. The daily intake of P was 1086.5 ± 361.3 mg/day; 64% contained in animal proteins, 22% in vegetable proteins, and 14% as inorganic P. The total amount of P ingested did not correlate with daily phosphaturia, but it did correlate with the P/UUN ratio (p < 0.018). Patients with the highest tertile of the P/UUN ratio >71.1 mg/g presented more abundant inorganic P intake (p < 0.038).The P/UUN ratio is suggested to be a marker of inorganic P intake. This finding might be useful in clinical practices to identify the source of dietary P and to make personalized dietary recommendations directed to reduce inorganic P intake.

scholarly journals Perceived discrimination and psychological distress among immigrants to Canada: The mediating role of bicultural identity orientations

2021 ◽  
pp. 136843022199008
Author(s):  
Mustafa Firat ◽  
Kimberly A. Noels
Keyword(s):  
Psychological Distress ◽  
Undergraduate Students ◽  
Structural Equation ◽  
Perceived Discrimination ◽  
The Other ◽  
Equation Modeling ◽  
Bicultural Identity ◽  
Cross Sectional ◽  
Mediating Role ◽  
The Relationship

Bicultural identity orientations have rarely been examined in relation to both perceived discrimination and psychological distress. Furthermore, these constructs have usually been studied in isolation, but their intersection is essential for understanding intercultural relations in multicultural societies. Using cross-sectional data from 1,143 Canadian undergraduate students from immigrant families, this study explored the relationship between perceived discrimination and psychological distress, and how bicultural identity orientations might mediate this relationship. The structural equation modeling results indicated that perceived discrimination was associated with higher levels of psychological distress and hybrid, monocultural, alternating, and conflicted orientations, but lower levels of complementary orientation. Alternating and conflicted orientations were related to higher psychological distress, whereas the other orientations were not. Alternating and conflicted orientations mediated the relationship between perceived discrimination and psychological distress, whereas the other orientations did not. The findings are discussed in light of theories on identity integration, rejection–identification, and acculturation.

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