Fluoride Delivery Systems Research Articles

Role of Fluoride in Dentistry: A Narrative Review.

Fluoride has performed a central role in the growth over the last fifty years. This report examines the present state of knowledge about fluoride's involvement in preventing dental caries. In recent years, our knowledge of the development of dental caries and the manner of operation of fluoride has been shifted. Dental caries is a constant procedure for enamel demineralization and remineralization, and fluoride plays an important part in this action by acting at the plaque-enamel contact. Fluoride's major method of action is now recognized as posteruptive. Fluoride's post-eruptive activity has led to the development of novel fluoride delivery systems. The importance of various fluoride delivery techniques on a population and societal level is discussed, along with suggestions.

Silver diamine fluoride as a proactive anti-caries tool: A review

The management of ECC by the regular stereotyped restorative methods alone is incapable, particularly in a vast community or developing countries like India, where we lack free availability of dental equipment and manpower. The announcement of silver diamine fluoride (SDF) as another fluoride delivery system is a breakthrough therapy with evidences of caries lesion arrest rates of about 70 percent. SDF presents as an advantageous modality and is favoured as a satisfactory interim treatment option for its less invasive nature and its inexpensiveness. Most of the researchers have reported SDF to be undeniably more potent cariostatic agent than the fluoride varnishes in arresting caries. Its anti -caries effectiveness was found to be alike on incipient dental caries, non-cavitated and cavitated lesions and no severe pulpal damage after SDF application has been reported. Hence it is justified to state that SDF is a competent, efficient, secure and a reasonable caries preventive tool which is time saving and also patient oriented. Keywords: Silver diamine fluoride (SDF), Cariostatic agents, Fluoride delivery systems, Early childhood caries (ECC), Caries prevention, Fluoride varnishes.

Remineralizing Potential of Clinpro® and Tooth Mousse Plus® on Artificial Carious Lesions.

Calcium phosphate and fluoride (F) delivery systems claim to facilitate enamel remineralization. To evaluate and compare (i) the remineralizing potential of Clinpro® Tooth Crème(CTC) and Tooth Mousse Plus®(TMP) on artificial carious lesions, and (ii) the benefit of 1000ppm F dentifrice prior to the application of CTC and TMP. Carious lesions, 200-300μm deep were produced by placing molars in demineralizing solution for 96h, sections 100-150μm thick were then randomly assigned to six groups(n=150). Specimens were treated thrice daily with a non-fluoridated(Group A), or fluoridated dentifrice[1000ppm, (Group B)], or CTC(Group C), TMP(Group D), fluoridated dentifrice followed by CTC(Group E), or a fluoridated dentifrice followed by TMP(Group F), and then subjected to a 10-day pH cycling model. Lesion evaluation involved polarizing light microscopy and microradiography. Posttreatment maximum mineral content at the surface zone(Vmax) was significantly increased in Groups B, C, and D compared to the other groups. The lesion depth(LD) decreased in Group D>Group C>Group E, and the net mineral content gain(ΔZ) in Group C>Group D, which did not reach statistical significance. CTC and TMP exhibited similar efficacy in remineralizing artificial carious lesions. Nevertheless, the net mineral gain or lesion consolidation following CTC use was higher than TMP.

Prevention of enamel demineralization with a novel fluoride strip: enamel surface composition and depth profile.

There is no topically applicable low concentration fluoride delivery device available for caries prevention. This study was aimed to assess the use of a low concentration (1450 ppm) fluoride strip as an effective fluoride delivery system against enamel demineralization. The enamel surface composition and calcium-deficient hydroxyapatite or toothpaste treatments were investigated using X-ray photoelectron spectroscopy. In vitro enamel demineralization was assayed using a pH cycling model and the dissolution of calcium ions from the treated specimens was quantified using ion chromatography. After 24-hr fluoride-strip treatment, the enamel was covered with a CaF2 layer which showed a granular morphology of 1 μm in size. Below the CaF2 layer was a region of mixed fluorapatite and CaF2. Fluoride infiltrated extensively in enamel to produce highly fluorinated fluorohydroxyapatite. In comparison, low-fluoride-level fluorinated fluorohydroxyapatite was formed on the enamel specimen exposed to toothpaste. The treatments with the fluoride strip as short as 1 hr significantly inhibited enamel demineralization. The fluoride strip was effective for topical fluoride delivery and inhibited in vitro demineralization of enamel by forming CaF2 and fluoride-containing apatites at the enamel surface. It exhibited the potential as an effective fluoride delivery device for general use in prevention of caries.

Efficacy of a fluoride-releasing orthodontic primer in reducing demineralization around brackets: An in-vivo study

A new, highly filled primer is currently marketed as a fluoride delivery system effective in reducing white spot lesions in orthodontic patients. However, no studies in the literature support this claim. The purpose of this in-vivo study was to investigate the retention and the efficacy of this primer in reducing the formation of white spot lesions. In each patient for whom premolar extractions were planned (n = 22), 1 premolar was randomly chosen as the experimental tooth for the application of the fluoride delivery system (Opal Seal; Ultradent Products, South Jordan, Utah), and the contralateral tooth was assigned as the control to receive the standard treatment (Transbond XT; 3M Unitek, Monrovia, Calif). After the bonding procedures, separators were placed around the premolar brackets to encourage plaque retention over 8 weeks. After the extractions, the tooth surfaces were evaluated visually and with microhardness techniques for demineralization. Primer retention was also investigated. There were no statistically significant differences in the numbers of white spot lesions between the 2 groups. The primer retention was calculated as 50%. The results indicated no significant difference between the efficacies of the fluoride-releasing primer and the control primer in reducing demineralization over the duration of the study.

Remineralizing efficacy of different calcium-phosphate and fluoride based delivery vehicles on artificial caries like enamel lesions

ObjectivesTo assess enamel remineralization of different calcium-phosphate and fluoride delivery systems. MethodsArtificial caries lesions were created on 115 extracted human molars. Specimens were assigned according to remineralizing agent into five groups: G1: Control (artificial saliva), G2: Clinpro™ white varnish, G3: Relief, G4: Tooth Mousse Plus, G5: Vanish™XT. Surface micro-hardness (SMH), surface roughness (Ra) and surface topography by scanning electron microscope (SEM) were evaluated at baseline, after demineralization, after 2 and 4 weeks remineralization and after acid challenge. ResultsDemineralized enamel showed the lowest SMH. By 2 weeks remineralization, SMH were ranked as follows: G2 (282.14±6.82)>G3 (269.37±7.25)>G5 (263.00±6.49)=G4 (251.83±8.26)>G1 (226.5±9.34). However, 4 weeks remineralization showed the following: G2 (304.09±6.65)>G3 (293.1±5.24)=G4 (285±7.29)>G5 (272.43±4.89)>G1 (233.33±9.12). By exposure to acid challenge, groups presented order of: G2 (279.71±5.99)=G3 (275.51±5.59)>G4 (262.29±6.65)>G5 (245.43±6.43)>G1 (190.27±8). Surface roughness showed the following mattress after 2 weeks remineralization: G1 (0.2488±0.0016)=G2 (0.2487±0.0007)=G3 (0.2476±0.0006)>G4 (0.2442±0.0004)>G5 (0.2396±0.0009). After 4 weeks remineralization: G1 (0.2469±0.0017)>G4 (0.244±0.0004)>G5 (0.2413±0.0008)=G3 (0.2405±0.0007)=G2 (0.2399±0.0006). After acid challenge; G1 (0.2582±0.0027)>G5 (0.2556±0.0007)>G4 (0.2484±0.0009)>G3 (0.2463±0.0007)>G2 (0.2443±0.0004). SEM revealed mineralized coating on the surfaces which resists dissolution by acid challenge at variable degrees according to remineralization regimen applied. ConclusionsRemineralizing agents containing different calcium-phosphate formulas and fluoride have increased remineralization potential compared to artificial saliva. Clinpro™ varnish presented the highest remineralization tendency with greatest resistance for acid challenge. Clinical significanceThis in vitro study imitated the application of different calcium phosphorous and fluoride based delivery vehicles to enamel tooth surfaces in the mouth. The new therapeutic techniques based on different calcium phosphate formulas containing fluoride provide a new avenue for remineralization of non-cavitated and early carious lesions.

Prevention and treatment of demineralisation during fixed appliance therapy: a review of current methods and future applications

Orthodontic treatment, like all aspects of dentistry, exposes the clinician to the risk of malpractice and litigation. Demineralisation of tooth enamel is still one of the main complications of orthodontic treatment and it is essential patients are made aware of this risk during the consent process. There are a variety of fluoride delivery systems (mouthrinse, varnish, bonding system, and elastics), which can be used to prevent white spot lesion (WSL) formation. Glass-ionomer bonding cements (GIC) have also been shown to reduce WSL formation and have the benefit of not relying on patient compliance. However, these materials have not found widespread acceptance, possibly due to handling characteristics. A number of new technologies, principally fillers and coatings, have recently become available with potential antimicrobial and antibiofilm properties. Coatings can be applied to brackets and wires, which prevent bacterial adhesion. However, the longevity of these coatings is questionable. There are a number of methods available aimed at reducing the incidence of WSL, but they all have limitations. Capitalising on technological advances will enable the production of tailor made orthodontic brackets and adhesive systems, which provide long-term protection against WSL without relying on patient compliance.

Development of a sustained fluoride delivery system

To develop a novel delivery system by which fluoride incorporated into elastomeric rings, such as those used to ligate orthodontic wires, will be released in a controlled and constant manner. Polyethylene co-vinyl acetate (PEVA) was used as the model elastomer. Samples (N = 3) were prepared by incorporating 0.02 to 0.4 g of sodium fluoride (NaF) into previously prepared PEVA solution. Another group of samples prepared in the same manner were additionally dip-coated in PEVA to create an overcoat. Fluoride release studies were conducted in vitro using an ion selective electrode over a period of 45 days. The amount of fluoride released was compared to the optimal therapeutic dose of 0.7 microg F(-)/ring/d. Only coated samples with the highest fluoride content (group D, 0.4 g of NaF) were able to release fluoride at therapeutic levels. When fluoride release from coated and uncoated samples with the same amount of NaF were compared, it was shown that the dip-coating technique resulted in a fluoride release in a controlled manner while eliminating the initial burst effect. This novel fluoride delivery matrix provided fluoride release at a therapeutically effective rate and profile.

The rational use of oral care products in the elderly.

This review examines the evidence of the effectiveness of oral care products in preventing and controlling dental caries and periodontal disease in the ageing population. The strength of evidence is indicated using the following hierarchy: Type 1 (systematic reviews), Type 2 (randomised controlled trials), Type 3 (observational studies) and Type 4 (traditional reviews). Most of the evidence to support the effectiveness of fluoride products is extrapolated from studies involving children and adolescents. The few studies that have been performed in older adults suggest that fluoride toothpaste and, in the case of high caries risk individuals, the adjunctive use of other fluoride delivery systems, may be effective in preventing coronal and root caries. Some dentifrices containing triclosan have been shown to improve plaque control and gingival health and one, which contains triclosan/copolymer, reduces the progression of periodontitis in adults and high-risk individuals. Powered toothbrushes with an oscillation-rotation action are more effective in reducing plaque and improving gingival health than manual toothbrushes.

Fluoride release from microporous poly(2-hydroxyethyl methacrylate) membranes

Fluoride ion is commonly used in the preventive treatment of tooth decay and when provided with extra fluoride, children living in regions that lack fluoride benefit from it. In the present study, the clinical properties of an intraoral controlled release fluoride delivery system were considered. Poly(2-hydroxyethyl methacrylate) (PHEMA) was examined as a fluoride carrier. Membranes were prepared by photopolymerization and then characterised. Contact angles and swelling ratios of fluoride-loaded membranes were determined. The surface morphology of the membranes were examined by using scanning electron microscopy. In vitro fluoride release studies were carried out in an artificial saliva medium. The concentration of fluoride was measured with a fluoride-specific electrode. The amount of released fluoride was determined and the effects of fluoride loading, medium pH and temperature on fluoride release were investigated. The swelling ratio of the PHEMA membrane was 58.5%, that of the fluoride-loaded PHEMA membrane was 17.8%. Increasing in the fluoride loading amount in the PHEMA membrane accelerated the fluoride release. The fluoride release ratio was increased with increasing pH and temperature.

Polyhydroxyethylmethacrylate/polyhydroxybutyrate composite membranes for fluoride release

AbstractControlled release technology is a recent technology which has considerable potential in the fields of medicine, pharmacy, and agriculture. Fluoride ion is commonly used in the preventive treatment of decay, and when provided with extra fluoride, children living in regions that lack fluoride benefit from it. For the present study, clinical properties of an intraoral controlled release fluoride delivery system were considered. The preparation of a controlled release membrane system is described. Polyhydroxyethylmethacrylate/polyhydroxybutyrate composite systems were examined as fluoride carriers. Polymeric membranes were prepared by photopolymerization and then characterized. Contact angles and swelling ratios of fluoride‐loaded membranes were determined. The surface morphology of the microporous membranes were examined by using scanning electron microscopy (SEM). In vitro fluoride release studies were carried out in an artificial saliva medium. The amount of released fluoride was determined and the effect of medium pH and temperature on fluoride release was investigated. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 976–981, 2003

An in situ model for simultaneous assessment of inhibition of demineralization and enhancement of remineralization.

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 (delta M, microns x vol%), compared with adjacent control sections retained in the lab, is calculated as change in delta Z (microns x vol%), namely, delta M = delta ZTEST - delta ZCONTROL.(ABSTRACT TRUNCATED AT 250 WORDS)

Sample Size Considerations in Designing Studies with Intra-oral Models

Especially during recent years, the use of pre-clinical models for predicting the efficacy of fluoride systems has assumed greater importance within the scientific community. Originally utilized primarily to screen experimental fluoride delivery systems, preclinical models are now being considered as predictors of clinical efficacy in lieu of controlled clinical caries trials. Of the various preclinical models presently available, human intra-oral models have the greatest potential for reflecting intended usage conditions and therefore may be the most meaningful models for predicting clinical efficacy. However, only with the proper consideration of numerous critical variables can studies using intra-oral models be appropriately designed to achieve the desired objectives. Clearly, these models must provide relevant information in a manner which reflects clinically established cariostatic activity and be capable of detecting established differences in the amount of cariostatic activity, i.e., dose-response effects. Three sources of variation must be considered before an appropriate study design and sample size can be chosen. Based on fluoride uptake data from an intra-oral model with proximally-located enamel specimens, estimates of variation among subjects, within subjects, and among specimens within subjects were obtained. Multiple specimens per panelist do not affect the first two sources of variation. Thus, the number of panelists, and not the number of specimens, is of primary importance when pre-test data are used to choose the appropriate study design and calculate the required sample size.

Effective delivery systems for prolonged fluoride release: review of literature

Controlled-release delivery systems have been investigated for use in fluoride therapy as a result of their ability to control the rate and site of fluoride release. Both sustained-release fluoride delivery systems and controlled-release fluoride preparations have been developed, including sustained-release fluoride tablets, fluoride-releasing polymers, microencapsulated fluoride in aerosols, and membrane-controlled fluoride reservoirs. Laboratory and clinical studies have confirmed the ability of these preparations to produce high levels of fluoride in saliva and plaque without toxic or adverse side effects. From these studies, it appears that controlled-release fluoride delivery systems have great potential as effective anticaries agents in cariesprone populations.

Antiplaque properties of sustained release SnF2: pilot studies.

Pilot studies examining the physical and clinical properties of an intracoronal sustained release fluoride delivery system were performed. After testing various percentages of SnF2 incorporated into polycarboxylate, zinc phosphate, and zinc oxide cements, 70% SnF2 polycarboxylate cement was found to have adequate compressive strength while releasing the greatest amount of fluoride in vitro. A 30-day in vivo trial, in which this fluoride cement was used as a temporary intracoronal restoration, produced elevated salivary fluoride levels with only transient elevation in urinary fluoride levels. Plaque scores decreased during the experimental period, suggesting that the released SnF2 affected bacterial growth or attachment. The SnF2-polycarboxylate cement was an adequate temporary restorative material without significant side effects.

Inhibition of Experimental Dental Caries Using an Intraoral Fluoride-Releasing Device

An intraoral fluoride releasing device designed to provide continual topical fluoride therapy for the prevention of dental caries was found to be effective in inhibiting caries in the rat model. Animals fitted with an intraoral device that released approximately 0.15 mg of fluoride per day developed 63% fewer carious enamel areas than animals receiving no treatment. Fluoridated drinking water (10 ppm) produced a 25% reduction in carious enamel areas. The fluoride-releasing device was more effective than ad libitum fluoridated drinking water in inhibiting caries on the approximal and sulcal surfaces. These results agree with the hypothesis that the continual presence of fluoride in oral fluids enhances the cariostatic effect of fluoride and, when combined with the results of earlier primate and human trials of the intraoral fluoride-releasing device, suggest that this fluoride delivery system can be developed into an effective anticaries agent.

Novel topical fluoride-delivery system for remineralization of dental enamel: optimization studies

Further studies have been conducted on a calcium fluoride delivery system with a view to optimizing its ability to remineralize dental enamel. The influence of particle size and load of calcium fluoride used, as well as treatment time, was evaluated in vitro on prior demineralized bovine enamel. Initial studies with the original singlemembrane system did not allow an unambiguous interpretation of efficacy, due to persistent interference from calcium fluoride particles. To overcome this problem, the system was modified to include a second membrane as protection for the enamel surface. This double-membrane system revealed a marked particle size and load effect on fluoride delivery. The performance of a high load of small size calcium fluoride particles was significantly better than previous results obtained with the system and approached the most effective remineralizing conditions established with solution fluoride.

Novel Topical Fluoride Delivery System I: Remineralization of Ground Bovine Teeth

Laboratory studies were carried out on a newly conceived fluoride-containing re-mineralizing system with bovine teeth. The prototype fluoride delivery device involved micronized calcium fluoride maintained at the tooth surface with a cellulose film. Together with salivary calcium and phosphate (or simulated saliva), this system was able to generate and maintain the appropriate thermodynamic activity driving force for significant fluorapatite deposition in a reasonably short time (-48 hr).