NaF Toothpaste Research Articles

Conventional and Anti-Erosion Fluoride Toothpastes: Effect on Enamel Erosion and Erosion-Abrasion

New toothpastes with anti-erosion claims are marketed, but little is known about their effectiveness. This study investigates these products in comparison with various conventional NaF toothpastes and tin-containing products with respect to their erosion protection/abrasion prevention properties. In experiment 1, samples were demineralised (10 days, 6 × 2 min/day; citric acid, pH 2.4), exposed to toothpaste slurries (2 × 2 min/day) and intermittently stored in a mineral salt solution. In experiment 2, samples were additionally brushed for 15 s during the slurry immersion time. Study products were 8 conventional NaF toothpastes (1,400–1,490 ppm F), 4 formulations with anti-erosion claims (2 F toothpastes: NaF + KNO₃ and NaF + hydroxyapatite; and 2 F-free toothpastes: zinc-carbonate-hydroxyapatite, and chitosan) and 2 Sn-containing products (toothpaste: 3,436 ppm Sn, 1,450 ppm F as SnF₂/NaF; gel: 970 ppm F, 3,030 ppm Sn as SnF₂). A mouth rinse (500 ppm F as AmF/NaF, 800 ppm Sn as SnCl₂) was the positive control. Tissue loss was quantified profilometrically. In experiment 1, most NaF toothpastes and 1 F-free formulation reduced tissue loss significantly (between 19 and 42%); the Sn-containing formulations were the most effective (toothpaste and gel 55 and 78% reduction, respectively). In experiment 2, only 4 NaF toothpastes revealed significant effects compared to the F-free control (reduction between 29 and 37%); the F-free special preparations and the Sn toothpaste had no significant effect. The Sn gel (reduction 75%) revealed the best result. Conventional NaF toothpastes reduced the erosive tissue loss, but had limited efficacy regarding the prevention of brushing abrasion. The special formulations were not superior, or were even less effective.

Can anti‐erosion dentifrices also provide effective plaque control?

Objective:While gingivitis and caries continue to be prevalent issues, there is growing concern about dental erosion induced by dietary acids. An oral hygiene product that protects against all these conditions would be beneficial. This study investigated the potential of two anti-erosion dentifrices to inhibit plaque.Methods:This was a randomized, three-period, two-treatment, double-blind, crossover study evaluating a stannous chloride/sodium fluoride dentifrice (SnCl2/NaF, blend-a-med® Pro Expert) and a popular anti-erosion dentifrice (NaF, Sensodyne® ProNamel™). During Period 3, subjects were randomized to repeat one treatment to evaluate any product carryover effects. Each treatment period was 17 days. Test dentifrices were used with a standard manual toothbrush. Digital plaque image analysis (DPIA) was employed at the end of each period to evaluate plaque levels (i) overnight (am prebrush); (ii) post-brushing with the test product (am post-brush); and (iii) mid-afternoon (pm). Analysis was conducted via an objective computer algorithm, which calculated total area of visible plaque.Results:Twenty-seven subjects completed the study. At all time points, subjects had statistically significantly (P ≤ 0.0001) lower plaque levels after using the SnCl2/NaF dentifrice than the NaF dentifrice. The antiplaque benefit for the SnCl2/NaF dentifrice versus the NaF dentifrice was: am prebrush = 26.0%; am post-brushing = 27.9%; pm = 25.7%.Conclusions:The SnCl2/NaF dentifrice provided significantly greater daytime and overnight plaque inhibition than the NaF toothpaste. When recommending dentifrice to patients susceptible to dental erosion, clinicians can consider one that also inhibits plaque.

Oral fluoride retention in orthodontic patients with and without fixed appliances after using different fluoridated home-care products

Objective. To evaluate oral fluoride (F) retention after using fluoridated toothpastes, rinsing solutions and chewing sticks (Miswaks) in orthodontic patients with and without orthodontic appliances. Material and methods. Nine orthodontic patients, with a mean age of 16 years, were included in a randomized, cross-over, experimental study. Six different home-care F products, two NaF toothpastes (0.32% and 1.1%), two NaF mouthwash solutions (0.05% and 0.2%) and two NaF-impregnated Miswaks chewing sticks (0.05% and 0.5%), were used both during the orthodontic treatment and 1 week after debonding. Unstimulated whole saliva and approximal saliva were collected from two interdental sites, before and up to 60 min after using each product for 2 min. The retention of F was calculated as the area under the 60-min F-clearance curve (AUC). Results. In general, the F concentrations at the various sites were higher before than after debonding. Moreover, the products with a high F content (toothpaste, mouthwash and Miswaks) resulted in higher F retention than the corresponding products with a lower F content. In whole saliva, the highest AUC values were found in patients using 0.2% NaF mouthwash, followed by 1.1% NaF toothpaste (p < 0.05). In approximal saliva, the retention values were highest after using 0.5% NaF-impregnated Miswaks in patients wearing orthodontic appliances (p < 0.001). Conclusions. The insertion of fixed orthodontic appliances appears to favor oral F retention for all the tested home-care F products. In addition, products with a high F content increase oral F retention.

Effect of Rinsing with Mouthwashes after Brushing with a Fluoridated Toothpaste on Salivary Fluoride Concentration

The aim of the study was to determine whether rinsing with a mouthwash after brushing with a fluoridated toothpaste affected oral fluoride (F) retention and clearance compared with an oral hygiene regime without mouthwash. In this supervised, single-blind study, 3 regimes were compared: (A) brushing for 1 min with 1 g of 1,450 μg F/g NaF toothpaste followed by rinsing for 5 s with 10 ml water; (B) as A but followed by rinsing for 30 s with 20 ml of 100 mg F/l NaF mouthwash, and (C) as B but rinsing for 30 s with a non-fluoridated mouthwash. Twenty-three adults applied each treatment once in a randomised order, separated by 1-week washout periods, and used a non-fluoridated toothpaste at home prior to and during the study. Whole saliva samples (2 ml), collected before each treatment commenced and 10, 20, 30, 60, 90 and 120 min afterwards, were subsequently analysed for fluoride by ion-specific electrode. The mean (SD) back-transformed log (area under salivary F clearance curve) values were: A = 2.36 (+3.37, –1.39), B = 2.54 (+2.72, –1.31) and C = 1.19 (+1.10, –0.57) mmol F/l × min, respectively. The values for regimes A and B were statistically significantly greater than that for regime C (p < 0.001; paired t test). These findings suggest that use of a non-F mouthwash after toothbrushing with a F toothpaste may reduce the anticaries protection provided by toothbrushing with a F toothpaste alone. The use of a mouthwash with at least 100 mg F/l should minimise this risk.

Effects of Flossing and Rinsing with a Fluoridated Mouthwash after Brushing with a Fluoridated Toothpaste on Salivary Fluoride Clearance

The aims of this study were to test the hypothesis that flossing after brushing with a fluoridated toothpaste may lower salivary fluoride (F), and to evaluate the consequence of subsequent F mouthwash use. Twenty adults used 3 oral hygiene regimes in a randomised order: A, brushing with an NaF toothpaste; B, as A but followed by professional flossing; C, as B followed by rinsing with an NaF mouthwash. Saliva samples were collected up to 120 min after each regime and analysed for F. The mean area under the clearance curve value for regime C was statistically significantly greater than the corresponding values for A and B (p < 0.0001), which differed little. The regime that included the mouthwash may provide better anticaries protection.

Effect of stannous fluoride toothpaste on erosion‐like lesions: an in vivo study

It has recently been shown that stannous fluoride (SnF(2)), in the form of aqueous solutions and as toothpaste, can reduce the dissolution of enamel in erosive acids in vitro and in situ. The aim of this study was to compare the effect of toothpastes containing SnF(2) or NaF on enamel dissolution using an in vivo model. Four healthy anterior teeth in each subject (n = 20) were exposed to diluted citric acid (100 mmol l(-1) or 10 mmol l(-1)) applied using a peristaltic pump (5 ml @7 ml min(-1)) and the acid was collected in a test tube before and after application of the respective toothpastes (etch I and etch II). Toothpaste was applied to the labial surfaces with a soft brush (four applications, each of 1-min duration), with gentle water rinsing between applications. Each subject had one pair of teeth treated with each of the test toothpastes. Enamel dissolution was examined by assessment of calcium content in the citric acid applied before and after the treatment with toothpaste. The results indicate that the SnF(2) toothpaste markedly reduced the dissolution of teeth in vivo (etch II < etch I), whereas the NaF toothpaste provided no protection (etch II > etch I). Toothpaste appears to be an acceptable vehicle for SnF(2) and maintains the dissolution-reducing effect exhibited by aqueous solutions of this fluoride salt.

Effect of a Solution with High Fluoride Concentration on Remineralization of Shallow and Deep Root Surface Caries in vitro

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.

Early natural subsurface caries. A SEM study of the enamel surface before and after remineralization.

The surface of natural proximal subsurface caries lesions was studied in a scanning electron microscope (SEM) before and after treatment and remineralization in an in vivo model. The material consisted of proximal subsurface lesions from 9 premolars. In 7 cases, one half of each lesion was studied directly and the other half remineralized in vivo before observation in the SEM. In 2 cases the same surface was studied before and after remineralization. The clinical treatment included effective oral hygiene, daily rinsing with 0.05% NaF solution, use of 0.1 % NaF toothpaste and application of Duraphat® varnish every 10th day for 8–10 weeks. The clinical result showed smooth and lustrous surfaces after 8–10 weeks. In the SEM the remineralized surfaces had a more regular and homogeneous appearance with more densely packed and larger crystallites compared to the untreated caries lesions. There was no difference regarding surface characteristics between parts where the lesions were still clinically visible and parts that were clinically healed. This indicates that clinical healing, in the sense that the area of the lesion is no longer clinically visible, does not depend solely on changes in the surface, but also on changes in deeper parts of the carious enamel.

Fluoride uptake by partially-decalcified enamel: a study of possible involvement of acid phosphate ions.

Ionic fluoride and HPO(2-)4 concentrations were determined in partially-decalcified enamels before and after exposure to NaF or MFP toothpastes, to determine whether fluoride uptake could be attributed to reactions with HPO(2-)4. Acid phosphate concentrations did not alter upon exposure to fluoride, even though large uptake of fluoride did occur. Infra-red spectroscopy showed HPO(2-)4 in artificially decalcified enamel to be adsorbed rather than present as a discrete secondary orthophosphate.

Plasma fluoride concentrations in pre-school children after ingestion of fluoride tablets and toothpaste.

Plasma fluoride (F) concentration and urinary F excretion were studied in 5 children, age 3–4 years, after intake of F tablets (0.5 mg) and 0.6 g of two NaF toothpastes containing 0.1 and 0.025% F – c