Search

Objectives. The present study aimed to investigate the relationship between fluoride concentration and mineral distribution within the dentinal lesion body. Methods. Remineralization of artificial deep dentinal lesions with various levels of fluoride was studied using a scanning electron microscope, microhardness tests, and polarized light microscope. Human molars were exposed to demineralization at pH 5.0 for 2 weeks. Then, they were divided into different groups for remineralization with different fluoride concentrations (0.1–10.0 ppm) for 1, 2, 3, and 4 weeks. Results. The results indicated a proportional relationship between fluoride concentration and dentinal lesion remineralization from 0.1 to 10.0 ppm. In the present study, the formation of a well-remineralized surface layer inhibited remineralization at the lesion front. On the other hand, the lesion front remineralization was found to be independent of fluoride concentration. Conclusion. Our results stated that for effective remineralization of dentinal lesions to the innermost part, fluoride levels from 1.0 to 5.0 ppm have the highest efficiency. [ABSTRACT FROM AUTHOR]

Copyright of Dilemas Contemporáneos: Educación, Política y Valores is the property of Dilemas Contemporaneos: Educacion, Politica y Valores and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Dental caries on (proximal) tooth surfaces is still a problem in many industrialized countries. The objectives of this review were to present the scientific basis and the principles of the resin infiltration concept, to discuss the inherent clinical applications, and to describe how these backgrounds can be integrated into the concept of minimal intervention dentistry. Data were identified by searches of the Cochrane Registers, Medline, and Scopus. Articles published in English and German through December 2008 were selected, and most up-to-date or relevant references were chosen. Cross-referencing of significant articles identified additionally relevant articles written in other languages and those of historical value. A total of 23 in vitro studies (focusing on penetration depths or demineralization prevention) were found, and 3 clinical studies (involving 122 subjects) could be retrieved; these studies were not comparable. With an increased understanding of the caries process, it is now recognized that demineralized but noncavitated enamel lesions can be arrested or remineralized in many situations. The clinical research evidence on the resin infiltration technique currently is of moderate extent to reach any decisive conclusions; however, based on available laboratory and clinical studies, it seems convincing that resin infiltration of enamel lesions should reduce (or even stop) the progress of white spot lesions. Combining this ultraconservative restorative approach (which is considered microinvasive) with a substantial caries remineralization program may provide therapeutic benefits and significantly reduce both long-term restorative needs and costs, thus complementing the concept of minimal intervention dentistry. [ABSTRACT FROM AUTHOR]

Objectives: To test how long casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) fluoride varnish prevents enamel demineralization in vitro. Materials and Methods: Human molars and premolars were sectioned buccolingually and randomly assigned to two groups. Standardized pretreatment images of enamel surfaces were obtained using FluoreCam. The control group received no treatment, and the experimental group received an application of CPP-ACP fluoride varnish. Over simulated periods of 2, 4, 8, and 12 weeks, specimens were placed in a toothbrushing simulator, thermocycled, subjected to 9 days of pH cycling, and imaged with FluoreCam. Samples were sectioned and polished for polarized light microscope (PLM) evaluation. Results: There were statistically significant time (P < .001) and varnish (P < .001) effects on area, intensity, and impact of enamel demineralization. The control group showed significant and progressive demineralization over the 12 weeks (P < .001). The experimental group revealed no significant demineralization during the first 4 weeks (P > .05) and significant (P < .001) increases thereafter. Experimental demineralization after 12 weeks was comparable to 2-week demineralization in the controls, with significant between-group differences (P < .001) in enamel demineralization at all time points. PLM of the control and experimental groups revealed lesion depths of 90 ± 34 im and 37 ± 9 im, respectively. Conclusions: Within the limitations of this in vitro study, CPP-ACP fluoride varnish prevents enamel demineralization for at least 4 weeks and limits demineralization up to 12 weeks. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Health Sciences (2447-8938) is the property of Unopar Cientifica Ciencias Biologicas e da Saude and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this double-blinded, randomized, cross-over in situ study was to evaluate the re- and demineralization characteristics of sound enamel as well as lowly and highly demineralized caries-like enamel lesions after the application of different fluoride compounds.Methods: In each of three experimental legs of 4 weeks, 21 participants wore intraoral mandibular appliances containing 4 bovine enamel specimens (2 lowly and 2 highly demineralized). Each specimen included one sound enamel and either one lowly demineralized (7 days, pH 4.95) or one highly demineralized (21 days, pH 4.95) lesion, and was positioned 1 mm below the acrylic under a plastic mesh. The three randomly allocated treatments (application only) included the following dentifrices: (1) 1,100 ppm F as NaF, (2) 1,100 ppm F as SnF2 and (3) 0 ppm F (fluoride-free) as negative control. Differences in integrated mineral loss (x0394;x0394;Z) and lesion depth (x0394;LD) were calculated between values before and after the in situ period using transversal microradiography.Results: Of the 21 participants, 6 did not complete the study and 2 were excluded due to protocol violation. Irrespectively of the treatment, higher baseline mineral loss and lesion depth led to a less pronounced change in mineral loss and lesion depth. Except for x0394;x0394;Z of the dentifrice with 0 ppm F, sound surfaces showed significantly higher x0394;x0394;Z and x0394;LD values compared with lowly and highly demineralized lesions (p < 0.05, t test).Conclusion: Re- and demineralization characteristics of enamel depended directly on baseline mineral loss and lesion depth. Treatment groups should therefore be well balanced with respect to baseline mineral loss and lesion depth. [ABSTRACT FROM AUTHOR]

The study investigated the erosion/abrasion-preventing potential of experimental NaF (1,400 ppm F-) and amine fluoride (AmF)/NaF/SnCl2/chitosan (1,400 ppm F-, 3,500 ppm Sn2+, 0.5% chitosan) toothpastes relative to placebo and SnF2 gel (970 ppm F-, 3,000 ppm Sn2+), and the impact of the demineralised dentine matrix on toothpaste effects. The study was a cyclic erosion/intervention experiment (10 days). Samples were stored in mineral salt solution either without or with collagenase (from Clostridium histolyticum type VII; 100 U/ml) for continuous removal of the organic matrix. To produce a comparable order of tissue loss, erosion was performed 6 × 30 s/day with 0.5% citric acid in the latter and 6 × 90 s/day with 1% citric acid in the former. Intervention was toothpaste slurry immersion (2 × 2 min/day); half of the samples were additionally brushed for 15 s within this time (brushing machine, load 200 g). Tissue loss was determined profilometrically (mean ± SD; µm). Tissue loss values (without/with brushing) for placebo, NaF, AmF/NaF/SnCl2/chitosan and SnF2 gel, respectively, were 11.6 ± 3.1/12.2 ± 2.5, 12.7 ± 3.1/10.7 ± 4.5, 8.7 ± 2.1/9.7 ± 2.1 and 8.8 ± 1.8/ 10.9 ± 1.8 in the presence of the organic matrix and 10.7 ± 3.2/11.9 ± 2.1, 8.2 ± 4.0/10.1 ± 4.1, 8.7 ± 2.9/9.1 ± 1.8 and 8.4 ± 1.9/7.5 ± 1.5 in the absence of the organic matrix. Relative to placebo, the NaF formulation had no significant effects; the AmF/NaF/SnCl2/chitosan formulation significantly reduced tissue loss between 20 and 25% except when applied without brushing in the absence of the organic matrix. The effects of the formulations were similar both in the presence and absence of the organic matrix. Sn2+/F-- containing formulations have the potential to reduce erosion/abrasion even in the absence of demineralised collagen; seeking for more effective formulations is desirable. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

The aim of this study was to analyse the predictive power of several clinical baseline parameters and the de-/remineralisation properties of in vivo etched sites measured with quantitative light-induced fluorescence (QLF) for subsequent 2-year caries increment. At baseline, in 44 children (8.23 ± 1.5 years) two areas (diameter 2 mm) of the buccal surface of a primary posterior tooth were etched with 36% phosphoric acid gel for 1 and 4 min, respectively. The etched sites were analysed immediately after etching (ΔQ1) and 24 h (ΔQ2) later by QLF. Additionally, caries status (deft/DMFT and initial caries), approximal plaque, bleeding on probing, and the patient's current use of fluorides were recorded. In the 2-year follow-up, 29 children were re-assessed. After clinical examination, the caries increment was calculated (ΔDMFT) and correlated with the baseline clinical variables and the QLF readings. Results showed a significant positive correlation between ΔQ1 min and the ΔDMFT (r = 0.44, p = 0.02). The ΔDMFT was significantly correlated with the baseline deft (r = 0.56, p = 0.002), cavitated active caries lesions (r = 0.52, p = 0.003), and filled teeth (r = 0.53, p = 0.003). In a regression analysis the use of fluoridated salt (SC = -0.10) and fluoride gel (SC = -0.14) were negatively associated with ΔDMFT. In conclusion, these findings suggest that the demineralisation properties of the etched sites and the outcome of the 24-hour measurements with QLF are significantly associated with caries increment. Previous caries experience strongly correlated with caries increment in this group of children. Copyright © 2012 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Dentine remineralization is clinically significant for prevention and treatment of dentine caries, root caries, and dentine hypersensitivity. However, dentine remineralization is more difficult than enamel remineralization due to the abundant presence of organic matrix in dentine. The objective of this study was to develop a biomimetic method to facilitate remineralization of demineralized dentine through phosphorylation of type I collagen in demineralized dentine using sodium trimetaphosphate. The experimental results indicated that the effect of fluoride on remineralizing dentine was limited when residual mineral crystals were lacking on the surface of demineralized dentine, whereas the phosphorylation and Ca(OH) pretreatment enhanced surface remineralization of the partially demineralized dentine. This biomimetic methodology resulted in favorable surface properties (i.e. highly negative charge and low interfacial free energy between substrate and aqueous medium) for crystal nucleation, and thus could be a promising method to remineralize superficially demineralized dentine lesions. [ABSTRACT FROM AUTHOR]

Objective. To evaluate the effect of milk supplemented with fluoride and/or probiotic bacteria on primary root caries lesions (PRCL) in older adults. Materials and methods. After informed consent, 160 healthy subjects, 58-84 years of age, with at least two PRCL were recruited and randomly assigned to one of four parallel study groups drinking 200 ml milk once daily for 15 months. Group A consumed standard milk (placebo); Group B ingested milk supplemented with 5 ppm F and probiotic bacteria ( Lactobacillus rhamnosus LB21, 107 CFU/mL); Group C drank milk with only probiotic bacteria and group D milk contained only fluoride. Primary endpoints were Root Caries Index (RCI) and electric resistance measurements (ECM) carried out by one blinded single examiner. Secondary endpoints were mutans streptococci and lactobacilli counts in saliva and plaque estimated with chair-side tests. Data were compared within and between groups with non-parametric tests. Results. The drop out rate was 38%. At baseline there were no statistical differences between the groups. Significantly higher numbers of RCI reversals were found in groups B, C and D compared with group A ( p < 0.05). The mean ECM values increased significantly ( p < 0.05) in all groups except for the placebo group A, indicating that remineralization occurred. The effect was most beneficial in the two groups that contained fluoride. No significant alterations were displayed regarding the microbial counts. No severe adverse effects were reported during intervention. Conclusion. Daily intake of milk supplemented with fluoride and/or probiotic bacteria may reverse soft and leathery PRCL in older adults. [ABSTRACT FROM AUTHOR]

This in situ/ex vivo study assessed the effect of different concentrations of fluoride in dentifrices on dentin subjected to erosion or to erosion plus abrasion. Ten volunteers took part in this crossover and double-blind study performed in 3 phases (7 days). They wore acrylic palatal appliances containing 4 bovine dentin blocks divided in two rows: erosion and erosion plus abrasion. The blocks were subjected to erosion by immersion ex vivo in a cola drink (60 s, pH 2.6) 4 times daily. During this step, the volunteers brushed their teeth with one of three dentifrices D (5,000 ppm F, NaF, silica); C (1,100 ppm F, NaF, silica) and placebo (22 ppm F, silica). Then, the respective dentifrice slurry (1:3) was dripped on dentin surfaces. While no further treatment was performed in one row, the other row was brushed using an electric toothbrush for 30 s ex vivo. The appliances were replaced in the mouth and the volunteers rinsed with water. Dentin loss was determined by profilometry and analyzed by 2-way ANOVA/Bonferroni test (a = 0.05). Dentin loss after erosive-abrasive wear was significantly greater than after erosion alone. Wear was significantly higher for the placebo than for the D and C dentifrices, which were not significantly different from each other. It can be concluded that the presence of fluoride concentrations around 1,100 ppm in dentifrices is important to reduce dentin wear by erosion and erosion + abrasion, but the protective effect does not increase with fluoride concentration. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

This study addressed the dose response between fluoride toothpastes and in vitro de- and remineralization, to predict the efficacy of toothpastes and understand the mode of action in the range 0–3,000 ppm F. Enamel lesions were pH-cycled with calcium uptake and loss being assessed daily. Both ‘shallow’ (about 50 μm deep) and ‘deep’ (about 200 μm deep) lesions were studied. F treatments were given in 30 (w/v)% toothpaste dilutions for up to 5 min daily. Calcium loss during the demineralization periods showed a dose response, resulting in 72% reduction for 3,000 ppm F compared to 0 ppm F. Calcium uptake during remineralization was increased in the F compared to non-F groups, with F concentration being less important than its mere presence. Significant differences were observed in F response between shallow and deep lesions, suggesting that this parameter should be included when testing caries-preventive products. Microradiographic analysis showed that lesion depth and severity had increased significantly in the non-F groups. In the F groups, the original lesion was partly remineralized, while a new lesion had formed beyond the original lesion front. Mineral loss of this second lesion correlated inversely with the F concentration of the treatments. These data revealed that fluoride can drive demineralization further into enamel by making the surface tissue less soluble, hence by not neutralizing acids penetrating into the tissue. It is also concluded that depth analysis of mineral uptake and loss is important to understand the mode of action of different F products. Copyright © 2006 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the effects of fluoride on erosive mineral loss in human enamel and dentine using a cyclic de- and remineralisation model in situ. The study was a three-treatment (5 days each) crossover design involving 4 (enamel) or 6 (dentine) healthy volunteers. Samples were recessed in palatal mouth appliances and worn day and night except during meals and were demineralised extraorally with 0.05 M citric acid (pH 2.3) for 6 x 5 min daily. Fluoridation was performed with toothpaste (SnF2/Olaflur; 0.14% F-) for 3 x 5 min daily (toothpaste fluoridation) or with toothpaste in combination with a mouthrinse (SnF2/Olaflur; 0.025% F-) for 3 x 5 min daily and with a gel (NaF/Olaflur, 1.25% F-) on days 1 and 3 instead of the toothpaste (intensive fluoridation). In the control group no fluoridation was performed. Mineral loss (microm) was determined with the use of longitudinal microradiography. In enamel, mineral loss was 40.7 +/- 15.1 microm in the control group, 18.3 +/- 12.4 microm after toothpaste fluoridation and 5.0 +/- 12.2 microm after intensive fluoridation. The respective values for dentine were 49.0 +/- 15.4, 35.0 +/- 15.5 and 19.8 +/- 12.0 microm. All differences were statistically significant (p < or = 0.001). The results indicate that intensive fluoridation is effective in preventing enamel and dentine from mineral loss even under severely erosive conditions. [ABSTRACT FROM AUTHOR]

Gerodontology 2004;21; 85–92Remineralisation study of artificial root caries lesions after fluoride treatment. An in vitro study using Electric Caries Monitor and Transversal Micro-RadiographyTo evaluate and compare remineralisation of root caries lesions after in vitro treatment with various fluoride (F) agents using an Electric Caries Monitor (ECM) and Transversal Micro-Radiography (TMR).Permanent human teeth were extracted and root surface specimens were sectioned, prepared (n = 35), and randomly allocated into seven different experimental groups (groups 1–7).Root surfaces were demineralised in an acidified gel (pH = 5.0) for 3 weeks followed by various F treatments and stored in a standardised remineralising solution at 37°C for 6 weeks. The root surfaces were treated twice daily with different dentifrice slurries for 2 min, either with a neutral placebo dentifrice without F (group 5); or a neutral sodium fluoride (NaF) 1400 p.p.m. F dentifrice (group 1); or a neutral 1250 p.p.m. F dentifrice (group 6); or an acid dentifrice (pH 4.7) with 1400 p.p.m. F containing amine fluoride (AmF) (groups 3 and 4) or a 1250 p.p.m. (pH 4.7) AmF dentifrice (group 6). In groups 1, 2, 5, 6, and 7, the root surfaces were additionally rinsed for 2 min with a neutral non-F placebo solution. In groups 3 and 4, rinsing were performed for 2 min with an acid (pH 4.7) 250 p.p.m. F solution, containing 125 p.p.m. F as AmF and 125 p.p.m. F as potassium fluoride (KF), once or twice per day respectively. ECM was used to measure electrical resistance on root surfaces at baseline and after 3 and 6 weeks respectively. TMR technique was used to measure and compare root surface lesion depths and mineral loss.Six weeks daily treatment with a dentifrice slurry containing AmF followed by rinsing with a combination of equal amounts of AmF and KF solution twice a day showed a statistical significant higher ECM values compared with the other groups. TMR data measuring lesion depths and mineral loss reduction supported the results of the ECM findings.Daily application of a dentifrice slurry containing 1400 p.p.m. F as AmF combined with twice daily rinsing with a 250 p.p.m. F solution containing equal amount of AmF and KF significantly remineralise primary root caries lesionsin vitro. ECM and TMR are valuable complementary methods in order to analyse the remineralisation processes. [ABSTRACT FROM AUTHOR]

A root dentin single-section model was developed to compare the efficacy of different fluoride treatments on the remineralization of lesions. Shallow (~170 μm) and deep (~400 μm) lesions were produced in acetic acid buffer solutions (pH 5.0) with 0.1- and 0.5-ppm fluoride for 3 days and 2 weeks, respectively. Next, the sections were pH-cycled for 4 weeks. Following the pH cycling, all sections were first remineralized for 5 weeks, then subjected to 10 days of demineralization. The treatments were (1) no treatment (control), (2) daily 1,450-ppm NaF toothpaste, (3) weekly 4,000-ppm fluoride solution, (4) a combination of treatments 2 and 3. In the shallow lesions, the 4,000-ppm fluoride solution and the combination treatment enhanced mineral deposition at the lesion front, producing a second, slightly hyperremineralized layer. Similarly, in the deep lesions a second remineralized layer was detected. In all lesions, the fluoride solution treatment showed significantly more remineralization compared to the control and the toothpaste treatment (p<0.05), most of which was formed during the pH cycling. In the demineralization period, the control showed significantly higher mineral loss than all other treatments. These results indicate that a 4,000-ppm fluoride solution might be effective for remineralization of root dentin lesions even over 400 μm depth. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the effect of fluoride on the progression of erosive demineralisation in human enamel and dentine using a cyclic de- and remineralisation model in vitro. The mineral content expressed in micrometres was determined daily by longitudinal microradiography (LMR) and presented as cumulative mineral loss over 5 days. For erosive demineralisation, all samples were immersed in 0.05 M citric acid (pH 2.3) for 6×10 min/day and stored in a remineralisation solution. Fluoridation measures were performed as follows: group 1: control, no fluoridation; group 2: toothpaste fluoridation 3×5 min/daily (NaF, 0.15% F-); group 3: toothpaste fluoridation as group 2 and additionally application of a fluoride mouthrinse (Olaflur/SnF2, 0.025%F-) 3×5 min/daily and on days 1 and 3 gel fluoridation (Olaflur/NaF; 1.25% F-) for 1×5 min. After the first experimental day, no significant differences were found between the groups. However, after 5 days the erosive mineral loss values for enamel were 147.5±18.7 μm in the control group, 128.1±15.0 μm in group 2 (p0.05) and 116.1±12.4 μm in group 3 (p0.001). In dentine, the respective values were 136.7±16.4, 111.8±26.9 (p0.001) and 60.3±17.8 (p0.001). The intensive fluoridation significantly reduced erosion progression in enamel but had a more pronounced effect on dentine. The results suggest that subjects with erosive lesions should use an intensive fluoridation measure. [ABSTRACT FROM AUTHOR]

Though the mineral distribution of the dentine carious lesion varies largely from tooth to tooth and from patient to patient, there are two main distribution profiles that characterize natural carious lesions in dentine. These profiles include softened and subsurface lesion types. The mineral distribution relationship between the starting profile and the profile after remineralization is not known. In order to study the relational aspects, we have produced demineralized dentine samples in vitro with mineral profiles similar to those of typical natural carious lesions, and subsequently remineralized the samples in a remineralizing solution with various fluoride concentrations (0, 2 and 10 ppm F). The mineral distributions were obtained by using an improved microradiographic technique. In addition, the nature of deposited mineral was analyzed by diamond-coupled total internal reflectance spectroscopy. Definite relationship was observed between the original lesion mineral distribution and the mineral distributions following remineralization. The amount of mineral present in approximately the first 50 μm of the lesion influenced the overall mineral profile after remineralization, possibly through influencing ion transport. If the amount was high (> approximately 10 vol%), the deposited mineral was confined to the surface (0-50 μm). The original mineral at those depths acted like a nucleus of mineral regrowth when the amount of residual mineral was intermediate, and like a transport barrier when the surface layer was well mineralized. If a surface barrier was not present, mineral was deposited at deeper depths in the lesion. Fluoride effect on dentine remineralization was dependent on the original mineral content and its distribution in the lesion. Although a high concentration of fluoride was very effective in low-mineral lesions, it produced hyperremineralization on well-mineralized subsurface lesions so that it prevented effective remineralization especially in deeper lesions. [ABSTRACT FROM AUTHOR]

The remineralization of whole human dentine treated with a neutral EDTA solution was investigated: the treatment periods were 15, 30 and 120 min. From the literature it is known that EDTA removes noncollagenous proteins (NCPs) from dentine powders. In order to extract more phosphoproteins from dentine lesions, in part of this work samples were also treated with 1 M NaCl or 4 M guanidine chloride solutions. All the dentine samples after the treatments mentioned were immersed subsequently in a remineralizing solution without fluoride for 2 weeks and microradiographed. To investigate the effects of fluoride, samples treated with EDTA for 120 min were also remineralized with 2ppm fluoride in solution. The results presented show that: (1) Measurable remineralization did not occur when fluoride was free in the remineralizing solution. Because remineralization occurred neither at the lesion front nor in the nonmineral part of the surface-softened tissue, presumably the NCPs (inhibitors) of underlying dentine diffused into the tissue during the remineralization period. (2) 2ppm fluoride caused remineralization at the lesion front. In this case we assume fluoride either acted as nucleating agent or overcame the NCP effects at the lesion front. [ABSTRACT FROM AUTHOR]

Demineralization of dentin in the presence of fluoride produces lesions with a mineralized surface layer which becomes thicker and more mineralized with higher fluoride concentrations whereas the lesion depth is hardly affected. The aim of this study was to investigate the effects of the time of fluoride treatment and the amount of fluoride taken up on the properties of the mineralized layer. Discs of bovine dentin embedded in methylmethacrylate with one surface exposed were demineralized in 50 mM acetic acid, 2.2 mM CaCl2, 2.2 mM KH2PO4, pH 5.0. At the start and/or later during the demineralization period, the specimens were incubated individually for 1 or 2 days in 10 ml of the same demineralization solution supplemented with 0.5, 2.0 or 5.0 ppm fluoride, which was then assessed for changes in calcium and fluoride concentrations. After 2, 5 and 8 days, specimens were sectioned for microradiographic analysis so as to follow development of the lesions and the mineralized layers. The results were the following: While demineralization with fluoride present at the first day led to the formation of a surface layer, fluoride present only at a later day produced a subsurface layer, not at the lesion front but closer to the surface. This layer resulted from (re)precipitation and not from preservation of the original mineral. The 'integrated mineral content' of the surface layer increased linearly with the uptake of fluoride, which resulted in an apparent fluorapatite content of about 20 vol%. The profiles of the surface layers remained unchanged during continued demineralization in the absence of fluoride. It was concluded that in the presence of fluoride mineral loss is reduced as a result of the reprecipitation of dissolved mineral ions as a layer of fluoride-enriched apatite. This layer does not offer protection of underlying dentin against continued demineralization. [ABSTRACT FROM AUTHOR]

Compared with the knowledge accumulated on enamel-fluoride interactions, relatively little data is available regarding fluoride effects on dentin. This applies to both laboratory and clinical studies into the efficacy of fluoride schemes for the prevention of root surface caries. This study aimed to determine the effects of fluoride and pH on the demineralization of dentin, such as to provide information necessary to develop preventive programmes. Bovine dentin blocks were subjected to undersaturated calcium- and phosphate-containing solutions in the pH range 4.0-6.0 with fluoride added at concentrations between 0.5 and 10 ppm. Non-fluoride solutions served as controls. Mineral loss was assessed chemically and by transversal microradiography. Comparisons were made with similar studies on enamel demineralization. The results showed that demineralization of dentin depends on both pH and fluoride concentration in the demineralizing solution. Inhibition of demineralization that could be relevant from a clinical point of view was found at fluoride values 5-10 times the corresponding values for enamel. Also rapid depletion of fluoride from the solutions was observed, indicating the high uptake capacity of dentin for fluoride. Lesion depth depended on pH of the solution while the fluoride levels were associated with the surface layer, both in mineral content and depth. For dentin we propose a demineralization mechanism where acid penetrates rapidly into the tissue, presumably through the tubules, after which the released calcium and phosphate is partly trapped by the inward diffusing fluoride. This leads to the formation of a surface layer, which may even be hypermineralized compared to sound dentin. [ABSTRACT FROM AUTHOR]

Root-surface caries, like enamel caries, develops as a subsurface type of mineral loss. Very little is known about the composition of the surface zone covering the body of the lesion, and the ultrastructure and composition of carious cementum are not known. The aim of this study was to correlate the ultrastructure and arrangement of the cementum crystals with the distribution of fluoride and calcium in root cementum from human teeth with sound, unexposed, or exposed root surfaces as well as in early stages of root-surface caries. Microradiographically, unexposed specimens showed a relatively homogeneous mineral distribution contrasting with the formation of an apparently highly mineralized surface layer in exposed and, in particular, in carious cementum. The electron-probe findings showed a substantial fluoride peak corresponding to the surface layers in carious tissues in particular, whereas the calcium profile in the surface did not reflect the apparent increase in mineralization. A substantial increase in size of the cementum crystals was found in specimens with formation of the fluoride-rich, well-mineralized surface zone. The crystal lattice intervals when observed along the (001) plane showed a hydroxyapatite spacing. The findings indicated that a significant crystal growth can be achieved in human cementum concomitant with fluoride accumulation. [ABSTRACT FROM AUTHOR]

Previous reports have shown a release of fluoride from glass-ionomer cement (GIC) restorations into the oral fluids. Fluoride in the ambient fluids has a caries-preventive effect by enhancing remineralization and inhibiting demineralization of the dental hard tissues. Therefore, the current investigation was undertaken to determine whether GIC fillings could contribute to the remineralization of caries lesions in dentin. Small circular preparations were made in disks of dentin which had incipient caries-like lesions in the remaining tissue. The preparations were filled with amalgam or composite materials (as controls) or with GIC. The specimens thus contained a restoration close to dentinal caries-like lesion. The specimens were place contralaterally in the buccal surfaces of removable partial dentures and were worn intra-orally by volunteers for a 12 week experimental period, after which the specimens were sectioned and analyzed by microradiography. All specimens with GIC restorations exhibited hypermineralization in the tissue bordering the filling and in the wall of the preparation which had been in contact with the restoration. The (caries-like) lesions were remineralized, even under conditions of heavy plaque formation. In contrast, specimens with amalgam or composite restorations showed further extensive demineralization. This study demonstrates a significant remineralization potential exerted by the fluoride-releasing GIC restorative material. Consequently, the choice of the restorative material might be crucial for the occurrence or prevention of recurrent caries around restorations. [ABSTRACT FROM AUTHOR]

This study assessed the incorporation of fluoride into remineralized enamel and the stability of the incorporated fluoride under various test conditions. Lesions were produced on bovine enamel slabs by a two-day immersion in 0.01 mol/L lactic acid buffer containing 3.0 mmol/L Ca, 1.8 mmol/L P, and 1% CMC adjusted to pH 4.0 at 37°C. The remineralizing solution contained the same amount of Ca, P. and CMC, plus 150 mmol/L NaCI and 3 ppm F, and was adjusted to pH 7. 0 at 37°C. All slabs were exposed to this unstirred solution, which was changed every two days during the ten-day remineralizing period. The remineralized slabs were divided into four groups. Group A (the control group) received no further treatment. The other three groups were exposed for 24 h to either the intra-oral environment (Group B), a 1. 0 mol/L KOH solution (Group C), or a 0. 01 mol/L lactic acid buffer (Group D). Fluoride incorporation assessed by abrasion biopsy in 10-µm layers showed about 10, 000 ppm F maximum in Group A. Similar levels of fluoride concentration from the surface to approximately 30µm thick were found in Groups A, B, and C. No appreciable fluoride was released from remineralized slabs from Groups B or C, and only a small fraction from Group D. Statistical analyses of the fluoride values showed no significant differences between the various test conditions in any of the layers sampled. No difference was evident in the Ca/P ratio between the ten-day remineralized enamel (Group A) and the treatment groups. The lack of appreciable fluoride loss from enamel with any of the above three conditions indicated a stable fixation of fluoride in the remineralized enamel lesions. [ABSTRACT FROM AUTHOR]

The way in which we conceptually consider dental caries determines our choice of preventive and treatment strategy. In this paper the definition of dental caries is discussed and the related problems concerning causality are addressed. Dental caries reflects symptoms of' ongoing and past disease - not the disease itself. As such, it is important to record early stages of signs of' the disease, i.e. non-cavitated stages of lesion development. The dynamic nature of the processes leading to net loss of' mineral (hence a lesion) is emphasized. and appreciating that caries is ubiquitous in populations around the world and initiation and progression of lesions continues lifelong leads to the logical conclusion that we can control dental caries through a variety of measures - but not truly prevent the disease. We can prevent cavities by controlling the pathophysiological events which may result in a net loss of mineral. The relative role of dental plaque in caries control is discussed in relation to the role of the many determinants which influence the likelihood for lesion development. It is concluded that several paradigms about the nature of dental caries should be reconsidered to provide the most cost-effective dental services. [ABSTRACT FROM AUTHOR]

The article focuses on the study which determines the level of fluoride intake from food and drink in children from 1-6 years old in Miyakonojou, Japan. The study includes the detection of fluoride concentration in the drinking water, the use of fluoride toothpaste, and the children's recommended fluoride dosage. The study investigates the children's duplicate diets including their beverages and snacks between the main meals. Results show that Japanese children have greater fluoride intake.