Mechanistic Aspects of the Interactions Between Fluoride and Dental Enamel

1991 ◽  
Vol 2 (3) ◽  
pp. 283-296 ◽  
Author(s):  
J.M. ten Cate ◽  
J.D.B. Featherstone

For many years after the discovery of its caries preventive effect, fluoride was thought to be primarily active by lowering the solubility of the apatitic mineral phase of the dental hard tissues. Recent findings have shed new light on the mechanisms by which fluoride inhibits or delays dental caries. Fluoride present in the oral fluids alters the rate of the naturally occurring dissolution and reprecipitation processes at the tooth-oral fluid interface. Demineralization of enamel is inhibited by concentrations of fluoride in the sub-ppm range. Likewise, remineralization of incipient caries lesions (the earliest stage of enamel caries) is accelerated by trace amounts of fluoride. As these two processes comprise dental caries the physiological balance between hard tissue breakdown and repair is favorably shifted by fluoride. The driving force for both phenomena is thermodynamic, that is, fluorapatite or a fluoridated hydroxyapatite may form when fluoride is supplied at low concentrations. This article critically reviews the current information about tooth-fluoride interactions, both from laboratory and clinical studies.

Author(s):  
V. Melnik ◽  
L. Gorzov ◽  
S. Melnik ◽  
Ya. Duganchik

Introduction. The largest amount of information about the dental caries is provided by the International Caries Detection and Assessment II system (ICDAS II), which is known as evidence-based approach to clinical visual detection of dental caries and enables to detect the stage and depth of carious lesions from the slightest changes in dental enamel to visible cavities affecting dentin. This system has been developed by the group of leading experts in the field of cariology. The results obtained by determining the ICDAS II index contribute to making right clinical decision in the choice of prevention and treatment methods, as well as to predicting the carious progression. The aim of the study is to assess the prevalence and intensity of initial dental caries in people using the ICDAS II index. Materials and methods. A total of 32 patients aged 12 to 25 years were examined. During the dental examination, we assessed the prevalence of dental caries using the ICDAS II. Clinical findings were recorded in oral follow-up charts proposed by the ICDAS Foundation for Epidemiological Studies, which allow us to record dental hard tissue status using six codes: three for assessing carious changes in enamel and three for assessing carious changes in dentine in a sequence of growing severity. Statistical processing of the findings was performed using Student's t-test. Results. Carious lesions were detected in all study participants, their total number was 285, of which 140 (49.1%) had the code 1 and 145 (50.8%) had the code 2 according to the ICDAS II. On average, each of the participants had 9.28 ± 0.67 foci of enamel demineralization. The average number of lesions with codes 1 and 2 by the ICDAS II was respectively 4.54 ± 0.51 and 4.74 ± 0.38 (p> 0.05). The average intensity of dental caries increased with age from 8.29 ± 0.83 in 12-15 year old individuals to 9.39 ± 1.20 in 18-25 year old individuals (p> 0.05), mainly by the growth of the average number of the mean number of caries lesions with the code 1 according to the ICDAS II. Mostly carious lesions are found on the masticatory surfaces, their total number made up 159 (55.7%). 101 (35.4%) caries lesions were found on the vestibular and oral parts of the tooth surfaces, and 25 (8.9%) average lesions were detected on the proximal surfaces. The average intensity of caries detected on the chewing surfaces of the teeth was 5.15 ± 0.49 and was significantly higher than on the vestibular and oral (3.33 ± 0.57, p <0.05) and proximal (0.79 ± 0, 20, p <0.001) surfaces. Conclusion. The obtained results showed a high intensity of carious lesions, with their predominance in the active stages in the two age groups under the study. This proves the appropriateness of using diagnostic ICDAS criteria for early detection of initial caries and its proper treatment.


2013 ◽  
Vol 592-593 ◽  
pp. 362-365 ◽  
Author(s):  
Roman I. Izyumov ◽  
Sergey V. Rusakov ◽  
Andrew L. Zuev ◽  
Olga S. Gileva ◽  
Maria A. Muraveva

The paper is concerned with the investigation of dental caries treatment by the modern method based on the application of special composite material that can diffuse into the damaged zone, harden by light and prevent tooth decay. Carious disease was modeled as a diffusion process of acid penetration from the oral cavity into the tooth enamel with further dissolution of dental hard tissues in the subsurface layer of enamel. The model of dental caries was mathematically formulated. The solution was obtained by a numerical method using MATLAB. It is shown that the proposed model adequately describes the properties of the examined dental system.


Author(s):  
E. Angeles Martínez-Mier

Fluoride is a naturally occurring element with multiple implications for human health. This review discusses its metabolism and toxicity, along with the current understanding of the mechanism of action of fluoride and its role as a safe and effective agent in the prevention of dental caries. The relationship between excessive fluoride intake during periods of dental enamel formation and the development of dental fluorosis is also reviewed.


Author(s):  
Miguel A. de Araújo Nobre ◽  
Ana M. Sezinando ◽  
Inês C. Fernandes ◽  
Andreia C. Araújo

Abstract Objective The study aimed to evaluate the influence of smoking habit on the prevalence of dental caries lesions in a follow-up study. Materials and Methods A total of 3,675 patients (2,186 females and 1,489 males) with an average age of 51.4 years were included. Outcome measures were the incidence of dental caries defined as incipient noncavitated, microcavitated, or cavitated lesions which had been diagnosed through clinical observation with mouth mirror and probe examination evaluating change of texture, translucency, and color; radiographic examination through bitewing radiographs; or secondary caries through placement of a new restoration during the follow-up of the study. Statistical Analysis Cumulative survival (time elapsed with absence of dental caries) was estimated through the Kaplan–Meier product limit estimator with comparison of survival curves (log-rank test). A multivariable Cox proportional hazards regression model was used to evaluate the effect of smoking on the incidence of dental caries lesions when controlled to age, gender, systemic status, frequency of dental hygiene appointments, and socioeconomic status. The significance level was set at 5%. Results Eight hundred sixty-three patients developed caries (23.5% incidence rate). The cumulative survival estimation was 81.8% and 48% survival rate for nonsmokers and smokers, respectively (p < 0.001), with an average of 13.5 months between the healthy and diseased state diagnosis. Smokers registered a hazard ratio for dental caries lesions of 1.32 (p = 0.001) when controlled for the other variables of interest. Conclusion Within the limitations of this study, it was concluded that smoking habit might be a predictor for dental caries.


Author(s):  
Maria D Ferrer ◽  
Salvadora Pérez ◽  
Aránzazu López Lopez ◽  
José Luis Sanz ◽  
Maria Melo ◽  
...  

Our aim was to evaluate clinical, biochemical and microbiological markers related to dental caries in adults. A sample that consisted of 75 volunteers was utilized. The presence of caries and the presence of plaque and gingival indices were determined. Unstimulated salivary flow, pH, lactate, Streptococcus mutans and Streptococcus dentisani were measured in the participants’ plaque and saliva samples before and after rinsing with a sugar solution. Lactate in plaque was found to be significantly related to age, gender, tooth-brushing frequency, the presence of cavitated caries lesions and plaque and gingival indices (p < 0.05). The levels of S. dentisani in plaque increased significantly with tooth-brushing frequency (p = 0.03). Normalized plaque S. dentisani values and the percentage of S. dentisani were slightly higher in patients with basal lactic acid levels ≤ 50 mg/L. After rinsing with a sugary solution, the percentage of S. mutans levels in plaque were higher in patients with lactic acid levels > 350 mg/L (p = 0.03). Tooth-brushing frequency was the factor which was most associated with oral health. Women reflected better clinical and biochemical parameters than men. Low pH and high lactic acid levels tended to be associated with high caries rates. No association was found between bacteria levels and caries indices.


1996 ◽  
Vol 42 (8) ◽  
pp. 1345-1349 ◽  
Author(s):  
J B Silkworth ◽  
J F Brown

Abstract Humans are exposed daily to low concentrations of many different chemical substances, natural and some man-made. Although many of these substances can be toxic at high levels, typical exposures are far below the effect levels. The responses produced by man-made aromatic hydrocarbon receptor agonists, such as dioxins, polychlorinated dibenzofurans, coplanar polychlorinated biphenyls, and polycyclic aromatic hydrocarbons, are also produced, often to greater extents [corrected], by naturally occurring constituents of fried meat, cabbage, broccoli, cauliflower, cocoa, and curry. Our society seems to be concerned about the health risks associated only with the synthetic chemicals, regardless of their proportional contribution to the total agonist activity, and regulates on the basis of such concerns. It would be more protective of the public health to determine acceptable concentrations for each type of response, regardless of the origin of the inducing agent, and issue advisories or regulations accordingly.


2012 ◽  
Vol 91 (9) ◽  
pp. 841-846 ◽  
Author(s):  
A. Ferreira Zandoná ◽  
E. Santiago ◽  
G.J. Eckert ◽  
B.P. Katz ◽  
S. Pereira de Oliveira ◽  
...  

2018 ◽  
Vol 7 (6) ◽  
pp. 509-520 ◽  
Author(s):  
Amitis Vieira Costa e Silva ◽  
Joás Araújo Teixeira ◽  
Cláudia C.B.O. Mota ◽  
Emery Clayton Cabral Correia Lins ◽  
Paulo Correia de Melo Júnior ◽  
...  

AbstractBackgroundNanosilver fluoride (NSF) was developed as an alternative in the prevention of dental caries.PurposeThe aim of this study was to test the remineralizing action of NSF on incipient enamel caries and its antimicrobial action on the acid production and adhesion of Streptococcus mutans.MethodsDeciduous enamel fragments were treated with sodium fluoride (NaF), NSF and deionized water. Microhardness, fluorescence spectroscopy and optical coherence tomography imaging were performed on each specimen before chemical caries induction, after caries induction and after 14 days of pH cycling. The treated enamel fragments were also placed into test tubes containing bacterial suspension and saliva. The pH readings and quantification of the adhered microorganisms to the dental enamel were determined. Analysis of variance, Kruskal-Wallis, Mann-Whitney, Tukey and mixed linear regression model were applied.ResultsNSF and NaF were effective in enamel remineralization, with a statistically significant difference (p<0.001) to deionized water, and they had no statistically significant difference between themselves (p>0.005). NSF had greater effectiveness compared to NaF in preventing decreases of pH and adhesion of S. mutans to the enamel surface, with statistically significant (p<0.001) differences.ConclusionNSF may be more effective than conventional fluorides in treating incipient caries lesions due to its remineralization and antibacterial actions.


2021 ◽  
Vol 12 ◽  
Author(s):  
Kay Andrin Gränicher ◽  
Lamprini Karygianni ◽  
Thomas Attin ◽  
Thomas Thurnheer

The self-produced matrix of biofilms, consisting of extracellular polymeric substances, plays an important role in biofilm adhesion to surfaces and the structural integrity of biofilms. In dentistry, biofilms cause multiple diseases such as caries, periodontitis, and pulpitis. Disruption of these biofilms adhering to dental hard tissues may pose a major challenge since biofilms show higher tolerance to antimicrobials and antibiotics than planktonic cells. In this study, the effect of low concentrations of chlorhexidine (CHX) on enzyme-treated multispecies oral biofilm was investigated in an in vitro model. Six-species biofilms were enzymatically treated by anaerobic growth in a medium containing DNase I and proteinase K. Biofilms were exposed to a low concentration of CHX at defined time points. After 64h, biofilms were either harvested and quantified by cultural analyses or stained for confocal laser scanning microscopy (CLSM) analyses using either Live/Dead kit or different fluorescent dyes. A mixture of YoPro1 and SYTOX™ Green, Fluorescent Brightener 28 (Calcofluor), and SYPRO™ Ruby Protein Gel Stain was used to stain total DNA, exopolysaccharides, and extracellular proteins, respectively. Extracellular DNA (eDNA) was visualized via an indirect immunofluorescence assay (Mouse anti-DNA IgG, Goat anti-Mouse IgG, Streptavidin-Cy3). Overall, the total colony-forming units significantly decreased after combined treatment with a low concentration of CHX and enzymes compared to the group treated with CHX alone (p&lt;0.001). These findings also apply to five species individually (Streptococcus mutans, Streptococcus oralis, Actinomyces oris, Veillonella dispar, and Candida albicans) occurring in the biofilms, with Fusobacterium nucleatum being the only exception. Furthermore, CLSM images showed less dense biofilms and a reduction in cell numbers after combined treatment compared to the group without enzymes. The combination of enzymes capable of disturbing the matrix integrity with antimicrobial agents thus appears to be a promising approach for biofilm disruption and killing.


2020 ◽  
Vol 15 (4) ◽  
pp. 5-10
Author(s):  
Bahlul Hamzaeb ◽  
Ayat Jafarova ◽  
Rena Huseynova ◽  
Rumia Abbasova ◽  
Shahla Yusubova ◽  
...  

Subject. This article analyzes existing theories about the prevalence and causes of dental caries, which is considered as a civilization disease. The crucial role of endogenous factors in the risk of caries, including a pulp and dental fluid, is noted. Data are given that acids do not actively participate in the process of demineralization, which is confirmed by numerous theoretical and hypothetical points. The role of some materials produced by dental industry based on this “pseudo-acidogenic” theory and used in the treatment of caries, as well as the false and negative consequences created by them in general, is analyzed, and adequate parallels are carried out. The purpose of the study was the theoretical justification of the key role of acetylcholine (the cholinomimetic mediator located on the Toms fibers) in the occurrence of dental caries. Methodology. Russian and foreign research works due to the etiology, prevalence and pathogenesis of dental caries were studied, and a comparative theoretical analysis of the available data on this issue was carried out. Results. Based on the results of numerous studies cited in the available literature and our studies, we performed an analysis of theoretical principles and substantiated the data that the process of demineralization occurring in dental caries cannot be caused by acids. Therefore, the only and decisive factor in the origin of the demineralization process is the occurrence of the process because of alkaline substances. Conclusions. Based on the studied references, we present the data that the most current theories of the etiopathogenesis of caries are imperfect in terms of solving the problem, which, in our opinion, requires further study of the process both of acetylcholine and the enzyme acetylcholinesterase inhibition in the local form and inside dental hard tissues.


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