scholarly journals A modified pH-cycling model to evaluate fluoride effect on enamel demineralization

2003 ◽  
Vol 17 (3) ◽  
pp. 241-246 ◽  
Author(s):  
Rosane Maria Orth Argenta ◽  
Cinthia Pereira Machado Tabchoury ◽  
Jaime Aparecido Cury
Keyword(s):  
Dose Response ◽  
Significant Negative Correlation ◽  
Enamel Surface ◽  
Cross Sectional ◽  
Enamel Demineralization ◽  
Human Enamel ◽  
Ph Cycling ◽  
Dose Response Effect ◽  
Mineral Loss

Since in vitro pH-cycling models are widely used to study dental caries, they should allow evaluations of fluoride effect on early stages of caries development. Therefore, acid etching on enamel surface must be avoided, enabling surface microhardness (SMH) analysis. In the present study, the pH-cycling model originally described by Featherstone et al.9 (1986) was modified to preserve the enamel surface and to produce early carious lesions that could be evaluated using SMH and cross-sectional microhardness (CSMH) measurements. In order to validate this modified model, a dose-response evaluation with fluoride was made. Human enamel blocks with known SMH were submitted to such regimen with the following treatments: distilled deionized water (DDW; control) and solutions containing 70, 140 and 280 ppm F. Data from %SMH change and deltaZ (mineral loss) showed a statistically significant negative correlation between F concentration in treatment solutions and mineral loss. In conclusion, the modified pH-cycling model allowed the evaluation of changes on the outermost enamel layer during caries development, and a dose-response effect of fluoride reducing enamel demineralization was observed.

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.

Effect of Whole Saliva Components on Enamel Demineralization In Vitro

1993 ◽  
Vol 4 (3) ◽  
pp. 357-362 ◽  
Author(s):  
J.D.B. Featherstone ◽  
J.M. Behrman ◽  
J.E. Bell
Keyword(s):  
Dental Enamel ◽  
Acid Resistance ◽  
Human Teeth ◽  
Cross Sectional ◽  
Basic Proteins ◽  
Enamel Demineralization ◽  
Whole Saliva ◽  
Flow Through ◽  
Mineral Loss

The aim of the present study was to use an in vitro enamel demineralization model (1) to confirm that whole saliva pretreatment conferred acid resistance to dental enamel and (2) to determine whether this phenomenon was attributable to specific salivary proteins, minerals, lipids, or some combination of these. Crowns of human teeth, each with one exposed window, were prepared in groups of ten. They were each pretreated by immersion individually in 4 ml of either (1) clarified whole saliva for 18, 72, or 168 h, (2) dialyzed saliva (3500 MWCO membrane), (3) the "flow-through" fraction from a DEAE separation of whole saliva (neutral and basic proteins), (4) the "eluted" fraction of a DEAE separation of whole saliva (anionic proteins), or (5) a combination of salivary lipids and the DEAE "flow-through" fraction of whole saliva (neutral and basic proteins). Control groups were group 6 with no pretreatment, group 7 pretreated for 168 h in a borate buffer (5 mmol/1), and group 8 pretreated in a mineral solution containing calcium (0.7 mmol/1) and phosphate (2.6 mmol/1). The crowns were then demineralized for 7 d in vitro (0.1 mol/1 acetate, 1 mmol/l Ca and phosphate, pH 5.0) to produce artificial caries-like lesions. Lesions were assessed by cross-sectional microhardness profiles, and mineral loss (AZ, μm x vol% mineral) calculated. Mineral loss (AZ) values decreased linearly with the square root of time of pretreatment by whole saliva, confirming a time-dependent protective effect of salivary pellicle against demineralization of enamel. Pretreatments (168 h) by whole saliva (group 1), dialyzed saliva (group 2), and lipid/'flow through" proteins (group 5) gave equivalent protection (approximately 55%). However, no protection was provided by DEAE-separated protein fractions (no lipid present) or by the mineral alone. The protection of surface enamel against demineralization appears to be given by a combination of specifically adsorbed salivary lipids and proteins.

scholarly journals Effect of fluoridated varnish and silver diamine fluoride solution on enamel demineralization: pH-cycling study

2006 ◽  
Vol 14 (2) ◽  
pp. 88-92 ◽  
Author(s):  
Alberto Carlos Botazzo Delbem ◽  
Maurício Bergamaschi ◽  
Kikue Takebayashi Sassaki ◽  
Robson Frederico Cunha
Keyword(s):  
Surface Microhardness ◽  
Cross Sectional ◽  
Silver Diamine Fluoride ◽  
Fluoride Solution ◽  
Treatment Groups ◽  
Enamel Demineralization ◽  
Percentage Loss ◽  
Ph Cycling ◽  
Mineral Loss ◽  
Silver Fluoride

OBJECTIVE: In the present investigation, the anticariogenic effect of fluoride released by two products commonly applied in infants was evaluated. METHODS: Bovine sound enamel blocks were randomly allocated to each one of the treatment groups: control (C), varnish (V) and diamine silver fluoride solution (D). The blocks were submitted to pH cycles in an oven at 37ºC. Next, surface and cross-sectional microhardness were assessed to calculate the percentage loss of surface microhardness (%SML) and the mineral loss (deltaZ). The fluoride present in enamel was also determined. RESULTS: F/Px10-3 (ANOVA, p<0.05) in the 1st layer of enamel before pH-cycling were (C, V and D): 1.61ª; 21.59b and 3.98c. The %SMH (Kruskal-Wallis, p<0.05) were: -64.0ª, -45.2b and -53.1c. %deltaZ values (ANOVA, p<0.05) were: -18.7ª, -7.7b and -17.3ª. CONCLUSION: The data suggested that the fluoride released by varnish showed greater interaction with sound enamel and provided less mineral loss when compared with silver diamine solution.

scholarly journals Effect of starch on the cariogenic potential of sucrose

2005 ◽  
Vol 94 (1) ◽  
pp. 44-50 ◽  
Author(s):  
Cecilia C. C. Ribeiro ◽  
Cínthia P. M. Tabchoury ◽  
Altair A. Del Bel Cury ◽  
Livia M. A. Tenuta ◽  
Pedro L. Rosalen ◽  
...  
Keyword(s):  
Animal Studies ◽  
Amylase Activity ◽  
Negative Control ◽  
Cross Sectional ◽  
Dental Biofilm ◽  
Enamel Demineralization ◽  
Two Phases ◽  
Mineral Loss

Sincein vitroand animal studies suggest that the combination of starch with sucrose may be more cariogenic than sucrose alone, the study assessedin situthe effects of this association appliedin vitroon the acidogenicity, biochemical and microbiological composition of dental biofilm, as well as on enamel demineralization. During two phases of 14 d each, fifteen volunteers wore palatal appliances containing blocks of human deciduous enamel, which were extra-orally submitted to four groups of treatments: water (negative control, T1); 2 % starch (T2); 10 % sucrose (T3); and 2 % starch+10 % sucrose (T4). The solutions were dripped onto the blocks eight times per day. The biofilm formed on the blocks was analysed with regard to amylase activity, acidogenicity, and biochemical and microbiological composition. Demineralization was determined on enamel by cross-sectional microhardness. The greatest mineral loss was observed for the association starch+sucrose (P<0·05). Also, this association resulted in the highest lactobacillus count in the biofilm formed (P<0·05). In conclusion, the findings suggest that a small amount of added starch increases the cariogenic potential of sucrose.

Effects of Fluoride Dentifrices on Enamel Lesion Formation

2008 ◽  
Vol 87 (3) ◽  
pp. 224-227 ◽  
Author(s):  
S. Toda ◽  
J.D. Featherstone
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Ion Concentration ◽  
Fluoride Ion ◽  
Lesion Formation ◽  
Cross Sectional ◽  
Human Enamel ◽  
Amine Fluoride ◽  
Ph Cycling

An in vitro pH cycling model was used to test the hypothesis that the effects of 3 different fluoride compounds on de/remineralization are a function of the free fluoride ion concentration. Groups of 10 human enamel specimens were treated with one of: (a) amine fluoride (AmF), 1250 ppm F; (b) sodium monofluorophosphate (NaMFP), 1000 ppm F; (c) sodium fluoride (NaF), 1100 ppm F; (d) NaF, 250 ppm F; (e) Placebo (< 1 ppm F) dentifrices; or with aqueous solutions (f) NaF 900 ppm F or (g) NaF 30 ppm F. Lesions were assessed by cross-sectional microhardness. Mean ± SEM ΔZ (vol.% x μm) values of 3 dentifrices were: (a) 344 ± 155, (b) 4259 ± 257, and (c) 591 ± 83. The AmF (1250 ppm F) was not statistically significantly different from the NaF (1100 ppm F) dentifrice in this model. The NaMFP (1000 ppm F) dentifrice, without hydrolysis, had only the same efficacy as the NaF (30 ppm F) aqueous solution.

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.

Synergistic Inhibition of Enamel Demineralization by Peptide 8DSS and Fluoride

2016 ◽  
Vol 50 (1) ◽  
pp. 32-39 ◽  
Author(s):  
Yang Yang ◽  
Xueping Lv ◽  
Wenyuan Shi ◽  
Xuedong Zhou ◽  
Jiyao Li ◽  
...  
Keyword(s):  
Mineral Content ◽  
Positive Control ◽  
Negative Control ◽  
Fluoride Uptake ◽  
Beneficial Effects ◽  
Enamel Demineralization ◽  
Demineralized Enamel ◽  
Ph Cycling ◽  
Mineral Loss

The biomimetic peptide 8DSS has shown beneficial effects in promoting remineralization of demineralized enamel in vitro. Here we examined the ability of 8DSS alone and in combination with fluoride to inhibit enamel demineralization during pH-cycling mimicking intraoral conditions. Enamel blocks were subjected to 9 days of pH-cycling in the presence of 1,000 ppm NaF (positive control), distilled-deionized water (DDW; negative control), 25 μM 8DSS alone, 25 μM 8DSS with 500 ppm NaF (8DSS-FL) or 25 μM 8DSS with 1,000 ppm NaF (8DSS-FH) twice daily for 1 min each time. The blocks were analyzed in terms of surface microhardness (SMH), fluoride uptake and mineral content. The 8DSS-treated blocks showed significantly lower mineral loss, shallower lesions and higher SMH than the DDW-treated blocks. No significant differences were observed between the blocks treated with 8DSS alone or fluoride alone. The blocks treated with 8DSS alone or DDW showed similar amounts of fluoride uptake, which was the lowest of all the treatment groups. The blocks treated with 8DSS-FL or 8DSS-FH did not differ significantly, and both groups showed significantly greater SMH and fluoride uptake as well as significantly lower mineral loss and shallower lesions than the NaF-treated blocks. Mineral content was significantly higher in the 8DSS-treated blocks than in the DDW-treated blocks from the surface layer (10 µm) to the lesion depth (110 µm), and it was significantly higher in the blocks treated with 8DSS-FL or 8DSS-FH than in the NaF-treated blocks from 10 to 90 µm. These findings illustrate the potential of 8DSS for inhibiting enamel demineralization and for enhancing the anticaries effect of NaF.

scholarly journals Enamel remineralization by fluoride-releasing materials: proposal of a pH-cycling model

2010 ◽  
Vol 21 (5) ◽  
pp. 446-451 ◽  
Author(s):  
Eliana Rodrigues ◽  
Alberto Carlos Botazzo Delbem ◽  
Denise Pedrini ◽  
Luciana Cavassan
Keyword(s):  
Dose Response ◽  
Response Relationship ◽  
Surface Microhardness ◽  
Dose Response Relationship ◽  
Cross Sectional ◽  
Microhardness Test ◽  
Significant Difference ◽  
Ph Cycling ◽  
And Control

This study proposes a pH-cycling model for verifying the dose-response relationship in fluoride-releasing materials on remineralization in vitro. Sixty bovine enamel blocks were selected for the surface microhardness test (SMH1). Artificial caries lesions were induced and surface microhardness test (SMH2) was performed. Forty-eight specimens were prepared with Z 100, Fluroshield, Vitremer and Vitremer ¼ diluted - powder/liquid, and subjected to a pH-cycling model to promote remineralization. After pH-cycling, final surface microhardness (SMH3) was assessed to calculate percent recovery of surface microhardness (%SMHR). Fluoride present in enamel (μg F/mm3) and in the pH-cycling solutions (μg F) was measured. Cross-sectional microhardness was used to calculate mineral content (∆Z). There was no significant difference between Z 100 and control groups on analysis performed on - %SMHR, ∆Z, μg F and mg F/mm3 (p>0.05). Results showed a positive correlation between %SMHR and μg F/mm3 (r=0.9770; p=0.004), %SMHR and μg F (r=0.9939; p=0.0000001), ∆ and μg F/mm3 (r=0.9853; p=0.0002), ∆ and μg F (r=0.9975; p=0.0000001) and between μg F/mm3 and μg F (r=0.9819; p=0.001). The pH-cycling model proposed was able to verify in vitro dose-response relationship of fluoride-releasing materials on remineralization.

Effects of Dentifrices Differing in Fluoride Content on Remineralization Characteristics of Dentin in vitro

2019 ◽  
Vol 54 (1) ◽  
pp. 75-86 ◽  
Author(s):  
Richard J. Wierichs ◽  
Katharina Rupp ◽  
Hendrik Meyer-Lueckel ◽  
Christian Apel ◽  
Marcella Esteves-Oliveira
Keyword(s):  
Dose Response ◽  
Analysis Of Covariance ◽  
Significant Difference ◽  
Before And After ◽  
Ph Cycling ◽  
Sound Treatment ◽  
Root Surfaces ◽  
Preventive Effects ◽  
Mineral Loss

Objectives: The aim of this study was to compare the caries preventive effect of highly fluoridated dentifrices and gels on sound dentin as well as on artificial dentin caries-like lesions. Methods: Bovine dentin specimens (n = 240), with 2 different surfaces each (1 sound surface [sound treatment (ST)] and one caries lesion [demineralized treatment (DT)]), were prepared and randomly allocated to one highly (6 × 120 min demineralization/day [H]) and one lowly cariogenic (6 × 60 min demineralization/day [L]) pH-cycling model. Treatments during pH-cycling (28 days) were: brushing 2×/day with: 0 ppm F [H0/L0], 1,450 ppm F [H1,450/L1,450], 2,800 ppm F [H2,800/L2,800], 5,000 ppm F [H5,000/L5,000], 5,000 ppm F plus TCP [H5,000+TCP/L5,000+TCP], and 12,500 ppm F [H12,500/L12,500] containing dentifrices/gels. Dentifrice/gel slurries were prepared with deionized water (1:2 wt/wt). Differences in integrated mineral loss (∆∆Z) and ∆ lesion depth were calculated between values before and after pH-cycling using transversal microradiography. Results: The correlation between ΔΔZDT and F– was strong for the highly (rH = 0.691; p < 0.001) and moderate (rL = 0.500; p < 0.001) for the lowly cariogenic model, indicating a fluoride dose-response for both. Significant differences for ΔΔZDT and ΔΔZST could be found between H0, H1,450, H5,000, and H12,500 as well as L0, L5,000, and L125,000 (p ≤ 0.046; analysis of covariance [ANCOVA]). Except for 0 ppm F–, no significant difference in ΔΔZST and ΔΔZDT could be found between the highly and lowly cariogenic model (p ≥ 0.056; ANCOVA). Conclusion: For both pH-cycling conditions a dose-response for fluoride could be revealed. For elderly people with exposed root surfaces, the use of gels containing 12,500 ppm F instead of regularly (1,450 ppm F) or highly (5,000 ppm F) fluoridated dentifrices should be further investigated, as it offered higher caries-preventive effects in vitro.

The Potential of a Bioactive, Pre-reacted, Glass-Ionomer Filler Resin Composite to Inhibit the Demineralization of Enamel in Vitro

2021 ◽  
Vol 46 (1) ◽  
pp. E11-E20
Author(s):  
IF Leão ◽  
N Araújo ◽  
CK Scotti ◽  
RFL Mondelli ◽  
MM de Amoêdo Campos Velo ◽  
...  
Keyword(s):  
Resin Composite ◽  
Surface Hardness ◽  
Composition Analysis ◽  
Glass Ionomer ◽  
Material Interface ◽  
Enamel Demineralization ◽  
Restorative Materials ◽  
Ph Cycling ◽  
Group B

Clinical Relevance A prereacted, glass-ionomer filler fluoride-containing resin composite had lower remineralization potential than glass-ionomer cements but was able to inhibit enamel demineralization; thus, it may be an option for restoring dental surfaces for patients at high risk of caries. SUMMARY Evidence is lacking on the use of surface prereacted glass-ionomer filler resin composites to inhibit demineralization and that simulate real clinical conditions. The present laboratory study evaluated the potential of such composites to prevent demineralization and quantified fluoride (F) and other ions released from restorative materials after a dynamic pH-cycling regimen applied to the tooth material interface in vitro. The pH-cycling regimen was assessed by measuring surface hardness (SH) along with energy dispersive X-ray spectroscopy (EDX). Methods and Materials: Ninety blocks of bovine enamel were subjected to composition analysis with EDX, and were further categorized based on SH. The blocks were randomly divided into 6 treatment groups (n=15 each): F IX (Fuji IX Extra; GC Corporation); IZ (Ion Z, FGM); F II (Fuji II LC, GC Corporation); B II (Beautifil II, Shofu); F250 (Filtek Z250 XT, 3M ESPE); and NT (control, no treatment). The blocks were subjected to a dynamic pH-cycling regimen at 37°C for 7 days concurrently with daily alternations of immersion in demineralizing/remineralizing solutions. EDX was conducted and a final SH was determined at standard distances from the restorative materials (150, 300, and 400 μm). Results: The EDX findings revealed a significant increase in F concentration and a decrease in Ca2+ in the enamel blocks of group B II after the pH-cycling regimen (p&lt;0.05). SH values for groups F IX, IZ, and F II were greater than those for groups B II, F250, and NT at all distances from the materials. Conclusions: The results suggest that each of 3 restorative materials, F IX, IZ, and F II, partially inhibited enamel demineralization under a dynamic pH-cycling regimen.

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