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.

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 Hypermobility and sports injury

2018 ◽  
Vol 4 (1) ◽  
pp. e000366 ◽  
Author(s):  
Joseph Alexander Nathan ◽  
Kevin Davies ◽  
Ian Swaine
Keyword(s):  
Statistical Analysis ◽  
Sports Injury ◽  
The Other ◽  
Anecdotal Evidence ◽  
Demographic Information ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Exact Test ◽  
Joint Dislocation ◽  
Ligament Sprain

ObjectiveTo determine whether there is an association between hypermobility and sports injury.MethodsA quantitative observational approach using a cross-sectional survey was adopted. Individuals were identified as hypermobile or not. All participants were asked to complete two questionnaires: one asking demographic information and the other injury-specific. Fisher’s exact test was used for statistical analysis.Results114 individuals participated in the study, 62 women and 52 men. 26% of the participants were hypermobile. There was no significant association between hypermobility and sports injury (p=0.66). There was a significant increase in joint and ligament sprain among the non-hypermobile (NH) group covering all sports (p=0.03). Joint dislocation was found exclusively among hypermobile individuals. The duration of injury in hypermobile individuals was higher than NH. The use of oral painkillers or anti-inflammatories in the semiprofessional group was greater than the general population.ConclusionHypermobility is relatively common among individuals, and there is a lot of anecdotal evidence associating it with increased rates of injuries. This project finds that NH individuals are more likely to sustain a ligament or joint sprain in sports. This is due to increased joint laxity and flexibility preventing injury. There were important limitations to this study which will be addressed in further work. These include assessing for pauciarticular hypermobility and focusing on one sport to investigate its association with sports injury in those who are hypermobile or not. It would also be important to focus on one specific joint, assessing its flexibility and association with injury.

scholarly journals Influence of storage solution on enamel demineralization submitted to pH cycling

2004 ◽  
Vol 12 (3) ◽  
pp. 205-208 ◽  
Author(s):  
Juliana Silva Moura ◽  
Lidiany Karla Azevedo Rodrigues ◽  
Altair Antoninha Del Bel Cury ◽  
Emilena Maria Castor Xisto Lima ◽  
Renata Matheus Cunha Rodrigues Garcia
Keyword(s):  
Enamel Surface ◽  
Human Teeth ◽  
Cross Sectional ◽  
Volume Versus ◽  
Enamel Demineralization ◽  
Ph Cycling ◽  
Storage Solution

Extracted human teeth are frequently used for research or educational purposes. Therefore, it is necessary to store them in disinfectant solutions that do not alter dental structures. Thus, this study evaluated the influence of storage solution on enamel demineralization. For that purpose, sixty samples were divided into the following groups: enamel stored in formaldehyde (F1), stored in thymol (T1), stored in formaldehyde and submitted to pH cycling (F2), stored in thymol and submitted to pH cycling (T2). All samples were evaluated by cross-sectional microhardness analysis and had their percentage of mineral volume versus micrometer (integrated area) determined. Differences between groups were found up to 30-µm depth from the enamel surface (p < 0.05), where samples from group T2 were more demineralized. It was concluded that the storage solution influenced the reaction of a dental substrate to a cariogenic challenge, suggesting that formaldehyde may increase enamel resistance to demineralization, when compared to demineralization occurring in enamel stored in thymol solution.

scholarly journals pH-cycling models to evaluate the effect of low fluoride dentifrice on enamel de- and remineralization

2008 ◽  
Vol 19 (1) ◽  
pp. 21-27 ◽  
Author(s):  
Celso Silva Queiroz ◽  
Anderson Takeo Hara ◽  
Adriana Franco Paes Leme ◽  
Jaime Aparecido Cury
Keyword(s):  
Dose Response ◽  
Polarized Light ◽  
Positive Control ◽  
Cross Sectional ◽  
Response Effect ◽  
Ph Cycling ◽  
Fluoride Dentifrice ◽  
Dose Response Effect ◽  
Bovine Enamel ◽  
Mineral Loss

Since the currently available pH-cycling models do not differentiate the anti-caries potential of dentifrices with low fluoride (F) concentration, two models were developed and tested in the present. Bovine enamel blocks were subjected to the models and treated with F solutions containing from 70 to 280 mug F/mL in order to validate them in terms of dose-response effect. The models were also tested by evaluating the dentifrices Colgate Baby (500 mug F/g, as a low fluoride dentifrice), Tandy (1,100 mug F/g, as an active F-dentifrice) and Crest (1,100 mug F/g, as positive control). Enamel mineral loss or gain was assessed by surface and cross-sectional microhardness, and lesion depth was analyzed by polarized light microscopy. The pH-cycling models showed F dose-response effect either reducing enamel demineralization or enhancing remineralization. The low F dentifrice presented anti-caries potential, but it was not equivalent to the dentifrices containing 1,100 mug F/g. These data suggest that the models developed in this study were able to evaluate the anti-caries potential of low F dentifrice either on resistance to demineralization or on enhancement of remineralization.

scholarly journals Influence of Fluoridated Groundwater and 1,100 Ppm Fluoride Dentifrice on Biomarkers of Exposure to Fluoride

2018 ◽  
Vol 29 (5) ◽  
pp. 475-482 ◽  
Author(s):  
Emerson Tavares de Sousa ◽  
Vanessa Feitosa Alves ◽  
Fabiana Barros Marinho Maia ◽  
Marinês Nobre-dos-Santos ◽  
Franklin Delano Soares Forte ◽  
...  
Keyword(s):  
Pearson Correlation ◽  
Linear Regression Analysis ◽  
Fluoride Concentration ◽  
Multiple Linear Regression Analysis ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional ◽  
Biomarkers Of Exposure ◽  
Fluoride Dentifrice ◽  
Pearson Correlation Analysis

Abstract This research aimed to determine the influence of fluoridated groundwater and 1,100 ppm fluoride dentifrice on biomarkers of exposure to fluoride in preschoolers. A cross-sectional study was performed on thirty preschoolers recruited from naturally fluoridated and non-fluoridated areas (n=15). Total Daily Fluoride Intake (TDFI) from diet and dentifrice, and Daily Urinary Fluoride Excretion (DUFE) was measured over 24 h. Nails samples were collected twice during 30 days. Fluoride analyses were performed using a fluoride-ion-specific electrode. Data were evaluated using the Student and paired t-test, Pearson correlation analysis, multiple linear regression analysis (α≤0.05). Fluoridated groundwater and dentifrice were the dominant sources (r2 > 0.83) of TDFI in children from a naturally fluoridated and a non-fluoridated area, respectively. A positive correlation between TDFI and DUFE (r=0.50), and between [F] in fingernails and toenails (r=0.60) were found in children from a naturally fluoridated area. The [F] in nails of finger and toe were not correlated to TDFI. The consumption of fluoridated groundwater influenced the fluoride concentration in urine. In addition, the use of 1,100 ppm fluoride dentifrice did not influence the fluoride concentration in urine and fingernails.

Effect of 5,000 ppm Fluoride Dentifrice or 1,100 ppm Fluoride Dentifrice Combined with Acidulated Phosphate Fluoride on Caries Lesion Inhibition and Repair

2017 ◽  
Vol 51 (3) ◽  
pp. 179-187 ◽  
Author(s):  
Constanza E. Fernández ◽  
Livia Maria Andaló Tenuta ◽  
Altair Antoninha Del Bel Cury ◽  
Diego Figueiredo Nóbrega ◽  
Jaime Aparecido Cury
Keyword(s):  
Fluoride Concentration ◽  
Negative Control ◽  
Double Blind ◽  
Cross Sectional ◽  
Caries Lesion ◽  
Risk Patients ◽  
High Fluoride ◽  
Fluoride Dentifrice ◽  
The Difference ◽  
Caries Lesions

High fluoride dentifrice (FD; 5,000 ppm F) has been recommended to arrest root dentine lesions and to control enamel caries in high-risk patients. Also, standard FD (1,100 ppm F) in combination with professional fluoride application has been recommended to control dentine caries, but the effect of this combination on enamel has been considered modest. Considering the lack of evaluation comparing the use of 5,000 ppm FD (5,000-FD) versus acidulated phosphate fluoride (APF) application combined with 1,100 ppm FD (1,100-FD) on the inhibition and repair of caries lesions in both enamel and dentine, we conducted this in situ, double-blind, crossover study of 3 phases of 14 days. In each phase, 18 volunteers wore palatal appliances containing enamel and root dentine specimens, either sound or carious, to evaluate the effect of the treatments on the inhibition or repair of caries lesions, respectively. The treatments were non-FD (negative control), 5,000-FD, or 1 APF gel application on dental specimens combined with 1,100-FD used twice per day (APF + 1,100-FD). The reduction of demineralization and enhancement of remineralization were assessed by surface and cross-sectional hardness. Fluoride concentration was determined on dental specimens and on the formed biofilm. For enamel, APF + 1,100-FD and 5,000-FD did not differ regarding the inhibition of demineralization and repair of caries lesions. However, for dentine the difference between these treatments was inconclusive because while APF + 1,100-FD was more effective than 5,000-FD in caries lesion reduction and repair, 5,000-FD was more effective than APF + 1,100-FD in the reduction of surface demineralization. Therefore, the findings show that the combination of APF + 1,100-FD is as effective as 5,000-FD in enamel inhibition of demineralization and enhancement of remineralization.

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 Enamel Subsurface Caries-Like Lesions Induced in Human Teeth By Different Solutions: A TMR Analysis

2020 ◽  
Vol 31 (2) ◽  
pp. 157-163
Author(s):  
Daiana Back Gouvêa ◽  
Nicole Marchioro dos Santos ◽  
Juliano Pelim Pessan ◽  
Juliana Jobim Jardim ◽  
Jonas Almeida Rodrigues
Keyword(s):  
Acetic Acid ◽  
Permanent Teeth ◽  
Deciduous Teeth ◽  
Human Teeth ◽  
Ph Cycling ◽  
Fluoride Dentifrice ◽  
Caries Lesions ◽  
Mineral Loss ◽  
Mineral Changes

Abstract This study assessed the effectiveness of models for developing subsurface caries lesions in vitro and verified mineral changes by transverse microradiography (TMR). Enamel blocks from permanent (n=5) and deciduous teeth (n=5) were submitted to lesion induction by immersion in demineralizing solutions during 96 h, followed by pH cycles of demineralization (de) and remineralization (re) for 10 days. Two de-/re solutions were tested. Demineralizing solution “A” was composed by 2.2 mM CaCl2, 2.2 mM KH2PO4, 0.05 M acetic acid, with pH 4.4 adjusted by 1 M KOH. Demineralizing solution “B” was composed by 2.2 mM CaCl2, 2.2 mM NaH2PO4, 0.05 M acetic acid and 0.25 ppmF, with pH 4.5 adjusted by 1M KOH. Solution “A” produced cavitated lesions in permanent teeth, whereas solution “B” led to subsurface lesions in deciduous teeth. Solution “B” was then tested in enamel blocks from permanent teeth (n=5) and subsurface lesions were obtained, so that solution “B” was employed for both substrates, and the blocks were treated with slurries of a fluoride dentifrice (1450 ppm F, as NaF, n=5) or a fluoride-free dentifrice (n=5). Solution “B” produced subsurface lesions in permanent and primary teeth of an average (±SD) depth of 88.4µm (±14.3) and 89.3µm (±15.8), respectively. TMR analysis demonstrated that lesions treated with fluoride-free dentifrice had significantly greater mineral loss. This study concluded that solution “B” developed subsurface lesions after pH cycling, and that mineral changes were successfully assessed by TMR.

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.

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