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 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.

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.

A Descriptive in vitro Electron Microscopic Study of Acidic Fluoride-Treated Enamel: Potential Anti-Erosion Effects

2015 ◽  
Vol 49 (6) ◽  
pp. 618-625 ◽  
Author(s):  
Carl Hjortsjö ◽  
Alix Young ◽  
Andreas Kiesow ◽  
Andreas Cismak ◽  
Lutz Berthold ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Focused Ion Beam ◽  
Surface Film ◽  
Ion Beam ◽  
Dental Enamel ◽  
Surface Films ◽  
Electron Microscopic ◽  
Human Teeth ◽  
Cross Sectional

This study aimed to investigate the surface zones of acidic fluoride-treated enamel. Human teeth were each divided into three or four enamel specimens that were treated for 10 min with solutions of 0.2 and 0.4% HF (pH 3.09 and 2.94), 1.74% SnF2 (pH 2.9), 0.68% TiF4 (pH 1.6) and 0.84% NaF (pH 4.5). Untreated specimens functioned as negative controls. The microstructure and elemental composition of the surface zones were studied by scanning electron microscopy/energy-dispersive X-ray (EDX) analysis, transmission electron microscopy (TEM) and nanospot-EDX following cross-sectional preparation using focused ion beam technology. TEM/EDX analyses of NaF-treated specimens showed a 500-nm-thick closed surface film containing 20-40 at% (atomic percent) F. HF-treated specimens had a distinct surface film 200-600 nm thick (dense, not globular) containing 45-47 at% F. TiF4-treated specimens had a surface film of 200-300 nm in thickness containing 8-11 at% Ti but no detectable fluoride. SnF2-treated specimens had a modified surface enamel layer varying in thickness from 200 to 800 nm with an inhomogeneous distribution of Sn. Local spots were detected with as high as 8 at% Sn (30 wt%, weight percent). The results suggest that the reaction mechanisms of SnF2 and TiF4 solutions with dental enamel differ from those occurring after enamel exposure to acidulated NaF and HF solutions. While the HF and NaF treatments resulted in the formation of CaF2-like material as shown by EDX, no significant surface fluoridation was found for SnF2 and TiF4 solutions within the TEM/EDX detection limits. These results suggest that the erosion-protective mechanisms of these latter compounds probably relate more to the formation of hardly soluble and acid-resistant reaction surface films and less to surface fluoride incorporation.

scholarly journals Effect of thickener agents on dental enamel microhardness submitted to at-home bleaching

2007 ◽  
Vol 21 (2) ◽  
pp. 170-175 ◽  
Author(s):  
José Augusto Rodrigues ◽  
Glauco Paulo Felício Oliveira ◽  
Cristiane Mariote Amaral
Keyword(s):  
Oxidation Reaction ◽  
Artificial Saliva ◽  
Dental Enamel ◽  
Experimental Treatment ◽  
The Other ◽  
Carbamide Peroxide ◽  
Dental Bleaching ◽  
Mineral Loss ◽  
At Home

Dental bleaching occurs due to an oxidation reaction between the bleaching agents and the macromolecules of pigments in the teeth. This reaction is unspecific and the peroxides can also affect the dental matrix causing mineral loss. On the other hand, recent studies have suggested that the thickener agent carbopol can also cause mineral loss. Thus, the objective of this study was to evaluate in vitro the effect of at-home dental bleaching on dental enamel microhardness after the use of bleaching agents with and without carbopol as a thickener agent. Bovine dental slabs with 3 x 3 x 3 mm were obtained, sequentially polished, and randomly divided into 4 groups according to the experimental treatment: G1: 2% carbopol; G2: 10% carbamide peroxide with carbopol; G3: carbowax; G4: 10% carbamide peroxide with poloxamer. Bleaching was performed daily for 4 weeks, immersed in artificial saliva. Enamel microhardness values were obtained before the treatment (T0) and 7 (T1), 14 (T2), 21 (T3), 28 (T4), and 42 (T5) days after the beginning of the treatment. ANOVA and Tukey's test revealed statistically significant differences only for the factor Time (F = 5.48; p < 0.01). All bleaching and thickener agents caused no alterations on the enamel microhardness.

An in sita Model for Simultaneous Assessment of Inhibition of Demineralization and Enhancement of Remineralization

1992 ◽  
Vol 71 (3_suppl) ◽  
pp. 804-810 ◽  
Author(s):  
J.D.B. Featherstone ◽  
D.T. Zero
Keyword(s):  
Tooth Enamel ◽  
Dental Health ◽  
Oral Care ◽  
Protective Effects ◽  
Cross Sectional ◽  
Food Component ◽  
Whole Saliva ◽  
Salivary Function

In situ models to assess the ability of oral care products or food components to enhance remineralization and/or inhibit demineralization of tooth enamel or roots must be very carefully designed to minimize the confounding effects of the many variables involved. Controlling these variables as closely as possible is essential if meaningful answers are to be obtained from the models. We have developed an in situ model which combines the experience of several groups. Detailed screening of subjects is essential. Selection criteria should include good general health, good dental health, mandibular partial denture, at least eight natural teeth, no active caries lesions, known fluoride history, normal salivary function, and no medications that affect salivary function. Each subject carries a sound enamel slab and an enamel slab with a pre-formed caries-like lesion (demineralized in vitro) in his/her denture on each side of the mouth for test periods of two or four weeks. The demineralization challenge is controlled by extra-oral immersion of the appliances in sucrose daily. Daily product exposure or daily food component exposure is used as desired. Compliance indicators and a diet diary are included. Whole saliva flow rate (unstimulated), plaque acidogenicity, and salivary fluoride are monitored during the test periods. At the end of the test period, the test slabs are assessed for mineral change, after being sectioned, by means of cross-sectional microhardness or microradiography. The mineral loss or gain (ΔM, μm × vol%), compared with adjacent control sections retained in the lab, is calculated as change in ΔZ (μm × vol%), namely, ΔM = ΔZTEST - ΔZ.CONTROL. In this model, demineralization occurs in sound enamel and in the pre-formed lesions in the absence of fluoride or other protective agents. The model has the potential to be able to differentiate among fluoride delivery systems and to assess the caries-protective effects of agents other than fluoride by use of small groups of subjects.

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 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 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.

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