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 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.

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 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 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 low fluoride acidic dentifrices on dental remineralization

2013 ◽  
Vol 24 (1) ◽  
pp. 35-39 ◽  
Author(s):  
Fernanda Lourenção Brighenti ◽  
Eliana Mitsue Takeshita ◽  
Camila de Oliveira Sant'ana ◽  
Marília Afonso Rabelo Buzalaf ◽  
Alberto Carlos Botazzo Delbem
Keyword(s):  
Surface Hardness ◽  
Positive Control ◽  
Negative Control ◽  
Cross Sectional ◽  
Enamel Demineralization ◽  
Ph Cycling

This study evaluated the capacity of fluoride acidic dentifrices (pH 4.5) to promote enamel remineralization using a pH cycling model, comparing them with a standard dentifrice (1,100 µgF/g). Enamel blocks had their surface polished and surface hardness determined (SH). Next, they were submitted to subsurface enamel demineralization and to post-demineralization surface hardness analysis. The blocks were divided into 6 experimental groups (n=10): placebo (without F, pH 4.5, negative control), 275, 412, 550, 1,100 µgF/g and a standard dentifrice (positive control). The blocks were submitted to pH cycling for 6 days and treatment with dentifrice slurries twice a day. After pH cycling, surface and cross-sectional hardness were assessed to obtain the percentage of surface hardness recovery (%SHR) and the integrated loss of subsurface hardness (ΔKHN). The results showed that %SHR was similar among acidic dentifrices with 412, 550, 1,100 µgF/g and to the positive control (Tukey's test; p>0.05). For ΔKHN, the acidic dentifrice with 550 µg F/g showed a better performance when compared with the positive control. It can be concluded that acidic dentifrice 550 µgF/g had similar remineralization capacity to that of positive control.

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 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.

scholarly journals Efficacy of S-PRG filler containing varnishes on enamel demineralization prevention

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Manuela da Silva Spinola ◽  
Sabrina Elise Moecke ◽  
Natália Rivoli Rossi ◽  
Toshiyuki Nakatsuka ◽  
Alessandra Bühler Borges ◽  
...  
Keyword(s):  
Positive Control ◽  
Negative Control ◽  
Cross Sectional ◽  
Enamel Demineralization ◽  
Ph Cycling ◽  
Knoop Microhardness ◽  
Bovine Enamel ◽  
Demineralization Prevention ◽  
Unprotected Area ◽  
One Way Anova

Abstract This study evaluated the efficacy of S-PRG vanishes on preventing enamel demineralization. Bovine enamel specimens were obtained, polished and the baseline Knoop microhardness was evaluated. Specimens were stratified into six groups (n = 15), according to the varnish applied: S10—experimental varnish containing 10% of S-PRG fillers, S20—20% of S-PRG fillers, S30—30% of S-PRG fillers; S40—40% of S-PRG fillers; PC (positive control)—5% of NaF; NC (negative control)—no treatment was performed. Half of enamel surfaces were protected to work as a control and varnishes were applied over the unprotected area. A demineralizing pH-cycling was performed, and surface and cross-sectional microhardness were measured. The percentage of microhardness of the treated area was calculated comparing with the untreated area. Statistical analysis was performed by one-way ANOVA and Tukey’s test (p = 5%). All experimental S-PRG varnishes protected against demineralization in relation to no treatment, but S40 was the most effective on the surface. For all depths, S30 and S40 were superior in enamel demineralization prevention than other S-PRG filler concentrations and 5% NaF. It was concluded that S-RPG filler containing varnishes were effective to prevent enamel demineralization. The higher concentrated products were more effective than 5% sodium fluoride on surface demineralization prevention.

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.

Cross-Sectional Hardness of Enamel from Human Teeth at Different Posteruptive Ages

2009 ◽  
Vol 43 (6) ◽  
pp. 491-494 ◽  
Author(s):  
C.A.B. Cardoso ◽  
A.C. Magalhães ◽  
D. Rios ◽  
J.E.O. Lima
Keyword(s):  
Human Teeth ◽  
Cross Sectional
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