SnF2 Dentifrice Research Articles

Effects of stannous fluoride dentifrice on gingival health and oxidative stress markers: a prospective clinical trial

BackgroundPeriodontal disease results in oral dysbiosis, increasing plaque virulence and oxidative stress. Stannous fluoride (SnF2) binds lipopolysaccharides to reduce plaque virulence. This study prospectively assessed SnF2 effects on oxidative stress in adults with gingivitis.MethodsThis was a 2-month, single-center, single-treatment clinical trial. Twenty “disease” (> 20 bleeding sites with ≥ 3 pockets 3 mm-4 mm deep) and 20 “healthy” (≤ 3 bleeding sites with pockets ≤ 2 mm deep) adults were enrolled. All participants were instructed to use SnF2 dentifrice twice daily for 2 months. An oral examination, Modified Gingival Index (MGI) examination and Gingival Bleeding Index (GBI) examination were conducted at baseline, 1 month and 2 months. Gingival crevicular fluid (GCF), saliva, oral lavage and supragingival plaque were collected at each visit to evaluate: Endotoxins, Protein Carbonyls, L-lactate dehydrogenase (LDH), Ferric reducing antioxidant power (FRAP), Oxidized low density lipoproteins (oxi-LDL), IL-6 and C-reactive protein (CRP). A subset-analysis examined participants considered at higher risk of cardiovascular disease. Change-from-baseline analyses within each group were of primary interest.ResultsThe disease group showed statistically significant reductions in GBI at Month 1 (67%) and Month 2 (85%) and in MGI at Month 1 (36%) and Month 2 (51%) versus baseline (p < 0.001). At baseline, the disease group showed greater LDH in GCF and oxi-LDL levels in saliva versus the healthy group (p ≤ 0.01). Total antioxidant capacity (FRAP) in saliva increased versus baseline for the disease group at Months 1 and 2 (p < 0.05), and levels for the disease group were greater than the healthy group at both timepoints (p < 0.05). SnF2 treatment reduced endotoxins (lavage) for both disease and healthy groups at Month 2 (p ≤ 0.021) versus baseline. There was a reduction in oxidative stress markers, namely protein carbonyl in saliva, at Months 1 and 2 (p < 0.001) for both groups and a reduction in cytokine IL-6 (lavage) in the disease group at Month 2 (p = 0.005). A subset analysis of participants at higher coronary disease risk showed reductions in endotoxins in lavage, oxi-LDL, and CRP in saliva at Month 2 (p ≤ 0.04).ConclusionSnF2 dentifrice use reversed gingival inflammation, suppressed endotoxins and reduced some harmful oxidant products in saliva and gingiva.Clinical trial registrationClinicaltrials.gov NCT05326373, registered on 13/04/2022.

Relationship between 1-, 3-, and 6-Month Gingival Bleeding Outcomes.

Results from systematic reviews and meta-analyses show generally consistent antigingivitis effects between 3- and 6-mo observation time points with twice-daily use of stannous fluoride (SnF2) dentifrice. However, the relationship between 1-, 3-, and 6-mo gingivitis responses has not been investigated. This pooled analysis was conducted to understand the relationship of 1-, 3-, and 6-mo gingival bleeding outcomes. Number of bleeding sites, derived from Löe-Silness Gingival Index (LSGI) or Gingival Bleeding Index, was identified as the primary end point of the analysis for the biological and clinical relevance. Randomized, double-blinded, controlled clinical studies meeting the following predefined selection criteria were identified: 1) published and unpublished gingivitis clinical trials conducted from 1995 to 2022 comparing efficacy of 0.454% SnF2 dentifrices to negative controls (sodium fluoride or sodium monofluorophosphate dentifrice) and 2) studies with a 3-mo assessment and at least a 1- or 6-mo assessment. The search resulted in ten 6-mo and fourteen 3-mo studies meeting selection criteria. A mixed-effects model was performed on the pooled data to assess gingival bleeding outcomes across time. The bleeding efficacy significantly increased between months 1 and 3 (P < 0.0001) and plateaued between months 3 and 6 (P = 0.007), supporting the fact that bleeding reduction relative to control established by 1 mo will increase and be maintained through 3 and 6 mo (R2 = 0.857). In addition, gingival bleeding and gingivitis efficacy, as measured by LSGI, were found to be highly correlated (R2 = 0.874). A clear relationship has been demonstrated between 1-, 3-, and 6-mo gingival bleeding outcomes in gingivitis clinical studies comparing SnF2 dentifrice to negative control dentifrice. These findings have important implications to the dental practice and scientific research as antigingivitis efficacy evaluations can be observed as early as 1 mo and are consistent with those seen at 3 or 6 mo. Outcomes from this investigation indicate that the clinical evaluation of antigingivitis efficacy at 1 mo is predictive of that at 3 and 6 mo, supporting studies of 1-mo duration as a viable method of knowledge acquisition. This more efficient, expedited research design has positive implications for patient care, clinical practice guidelines, protocols, and policies.

Effect of a Stannous Fluoride Dentifrice on Biofilm Composition, Gene Expression and Biomechanical Properties.

An in situ study was conducted to examine the mode of action of a 0.454% stannous fluoride (SnF2)-containing dentifrice in controlling the composition and properties of oral biofilm. Thirteen generally healthy individuals participated in the study. Each participant wore an intra-oral appliance over a 48-h period to measure differences in the resulting biofilm’s architecture, mechanical properties, and bacterial composition after using two different toothpaste products. In addition, metatranscriptomics analysis of supragingival plaque was conducted to identify the gene pathways influenced. The thickness and volume of the microcolonies formed when brushing with the SnF2 dentifrice were dramatically reduced compared to the control 0.76% sodium monofluorophosphate (MFP)-containing toothpaste. Similarly, the biophysical and nanomechanical properties measured by atomic force microscopy (AFM) demonstrated a significant reduction in biofilm adhesive properties. Metatranscriptomic analysis identified pathways associated with biofilm formation, cell adhesion, quorum sensing, and N-glycosylation that are significantly downregulated with SnF2. This study provides a clinically relevant snapshot of how the use of a stabilized, SnF2 toothpaste formulation can change the spatial organization, nanomechanical, and gene expression properties of bacterial communities.

Virucidal Activity of Over-the-Counter Oral Care Products Against SARS-CoV-2.

The oral cavity is an important entry point for SARS-CoV-2 infection. This study tested whether four commercially available mouthrinses and dentifrices have in vitro virucidal activity against SARS-CoV-2 (=4 log10 reduction in viral titer). One part of stock SARS-CoV-2 virus plus one part 0.3 g/l bovine serum albumin were mixed with eight parts of test product solution. After 30 s for the rinses, or 60 s for the dentifrices, the mixture was quenched in an appropriate neutralizer, serially diluted, and inoculated onto Vero E6 cells to determine viral titer. Triplicate runs were performed for each test condition with appropriate controls for test product cytotoxicity, viral interference, and neutralizer effectiveness. Test products included: 1.5% hydrogen peroxide (H2O2) rinse; 0.07% cetylpyridinium chloride (CPC) rinse; 0.454% stannous fluoride (SnF2) dentifrice A; and 0.454% SnF2 dentifrice B. ?The 1.5% H2O2 rinse, 0.07% CPC rinse, SnF2 dentifrice A, and SnF2 dentifrice B all produced > 4 log10 reduction in SARS-CoV-2 titer. All four test products displayed potent virucidal activity in vitro. Clinical studies are warranted to determine what role, if any, these oral care products might play in preventing transmission of SARS-CoV-2 or in the management of patients currently diagnosed with COVID-19 illness.

The effects of pediatric dentifrices with different types of fluoride on the color change of restorative materials.

This study aimed to evaluate the effects of dentifrices with different fluoride content on color change of restorative materials commonly used in pediatric dentistry. Three restorative materials (glass hybrid [Equia Forte (EF)], glass carbomer [GCP Glass Fill (GCP)] and compomer [Dyract XP (DXP)]) were used to prepare 120 disc shaped specimens by using a Teflon ring. Four dentifrice groups were created as Sodium Fluoride (NaF), Amine Fluoride (AmF), Stannous Fluoride (SnF2) and no-fluoride (n=40). Simulated tooth brushing was performed for each specimen by applying 6720 strokes for 6 months. Color changes [CIEDE2000 (Δ𝐸00)] were calculated by using generalized linear model procedure and the data were subjected to two-way analysis of variance. The highest color changes for NaF and AmF dentifrice groups were observed in the GCP restorative material (p<0.05). The color changes of restorative materials tested with SnF2 dentifrice group were statistically different (p<0.05) in each restorative material and Δ𝐸00 values were observed as GCP> EF>DXP. SnF2 dentifrice provided better color stability for all restorative materials when compared to NaF and AmF dentifrices; although, this was not statistically significant. GCP underwent significant discoloration values when brushed with all types of dentifrices. Although the glass carbomers caused significant color change, the compomers seem to be more resistant to the color change when brushed with all types of dentifrices. The fluoride content of dentifrices is crucial for the color change of restorative materials.

Investigation of oral malodor prevention by dentifrices as measured by VSC reduction

The oral malodor reduction efficacy of dentifrices containing stannous fluoride (SnF2) or zinc plus arginine (Zn/Arg) was evaluated using a halimeter to measure volatile sulfur compounds (VSCs) in two randomized, controlled, single-blind, cross-over pilot clinical trials. Study 1 (N = 16) had five 1100 ppm F dentifrices and five treatment periods: negative control (NC): 0.243% sodium fluoride (NaF); SnF2 A: 0.454% SnF2 + pyrophosphate; SnF2 B: 0.454% SnF2 + sodium hexametaphosphate; SnF2 C: 0.454% SnF2 + citrate; and SnF2 D: experimental 0.454% SnF2 with increased bioavailable Sn. Study 2 (N = 16) had four 1450 ppm F dentifrices and four treatment periods: NC: 0.1% NaF + 0.76% sodium monofluorophosphate; Zn/Arg: NaF + zinc + arginine; SnF2 E: 0.454% SnF2 + 0.078% NaF + sodium hexametaphosphate; SnF2 F: 0.454% SnF2 + 0.078% NaF + citrate. Each period took 96 h; baseline (day 0) morning to day 4 morning. Subjects brushed 2x/day with the treatment dentifrice. VSC levels were measured in the morning, prior to morning brushing, on days 0 and 4. Changes in VSC scores from day 0 to day 4 were assessed using a mixed-model analysis of covariance for cross-over studies. In study 1, SnF2 dentifrices B, C and D showed statistically significant reductions (31.3%, 24.8%, 34%, respectively) in VSC scores versus baseline (p < 0.001); the benefits of these treatments versus NC and SnF2 dentifrice A were statistically significant (p ⩽ 0.001). In study 2, SnF2 dentifrices E and F showed statistically significant reductions (31.2%, 22.1%, respectively) in VSC scores versus baseline (p ⩽ 0.010); the benefits of these treatments versus NC and the Zn/Arg dentifrice were statistically significant (p ⩽ 0.035). The Zn/Arg dentifrice showed a significant increase of 35.2% (p < 0.001) in VSC scores versus baseline. These studies demonstrated that SnF2 dentifrices can provide significant oral malodor reductions, but the benefit is formulation dependent. The presence of SnF2 is not sufficient to ensure efficacy. The Zn/Arg dentifrice increased VSC levels, indicating greater malodor. Clinical Trial Numbers: 20190429 and 20191028

The effect of mouthwashes on fluoride dentifrices in preventing dental abrasion or erosion.

Erosive tooth wear (ETW) refers to the chemical dissolution of mineralized tissues by acids of non-bacterial origin. It occurs in the primary as well as the permanent dentition. In this study, our objectives were to investigate and compare the impact of chlorhexidine gluconate (CHX), essential oils (EO), and cetylpyridinium chloride (CPC) on ETW protection produced by conventional fluoride kinds of toothpaste. A clinically relevant in-vitro erosion/abrasion pH cycling model was employed to test the effect of the aforementioned mouthwashes on modulating the ability of NaF and SnF2 types of toothpaste. The mean dentin surface loss associated with NaF toothpaste was significantly lower than for the SnF2 toothpaste. On the other hand, enamel surface loss with SnF2 toothpaste was significantly lower than for the NaF toothpaste. Also, the surface loss of erosion was significantly higher when associated with abrasion than without brushing and for both enamel and dentin. There was no significant difference in the surface loss among all types of mouthwash. Commonly used types of mouthwash containing antimicrobial agents or additional fluoride do not impact fluoride toothpaste action on erosion/abrasion. Also, considering erosion only, the tested SnF2 dentifrice provided better protection against surface loss of enamel than the other.

Measurement of eroded dentine tubule patency and roughness following novel dab-on or brushing abrasion

ObjectivesTo investigate the effect of dab-on or brushing of stannous-fluoride SnF2 or sodium-fluoride NaF dentifrice on eroded dentine tubule patency, surface and inter-tubular dentine roughness, using Confocal-Laser-Scanning-Microscopy (CLSM), Atomic-Force-Microscopy (AFM), Energy-Dispersive-X-ray-Spectroscopy (EDX), Scanning-Electron-Microscopy (SEM) and Contact-Profilometry (CP). Methods75-polished human dentine samples were prepared and eroded in agitated 6% citric acid to expose patent tubules and ‘initiate’ DH. Samples were randomly allocated into 5 intervention groups; artificial saliva control (1); electric tooth-brushing with NaF (2) or SnF2 (3), and dab-on application of NaF (4) or SnF2 (5). Samples underwent three cycles of intervention followed by further acid challenge. Patent tubules, likely to cause DH clinically, were measured using validated biocomputational methods with CLSM images of dentine surfaces taken baseline and post-intervention. Randomised samples (n = 15, 20 %) were investigated using AFM, EDX and SEM to study surface and sub-surface tubular occlusion. Dentine surface and inter-tubular roughness were measured using CP and AFM respectively. ResultsAt baseline, mean tubule patency in all samples was 216 (SD 58) with no significant inter-group differences. Post-intervention, the mean patency was 220 (40) and 208 (35) in groups 1 and 2 respectively (p ≥ 0.06), but decreased to 62 (41), 62 (21) and 63 (19) in groups 3, 4 and 5 respectively (p < 0.0001). Patency was confirmed using AFM, SEM and EDX. SnF2 interventions created greater sub-surface occlusion (p < 0.01), and increased CP surface roughness (p = 0.015). Significant negative correlation (-0.6) existed between CP surface roughness and tubule patency (p = 0.009). ConclusionsDab-on with NaF and SnF2 or brushing with SnF2 reduces DH in eroded dentine with ongoing acid challenges. Contacting surface roughness measures indicate risk of DH. Clinical significanceDab-on is a convenient supplementary method of dentifrice application to reduce DH; it beneficially avoids brushing post-erosion or overzealous brushing, enables re-establishment of an appropriate brushing regime post-DH and supports oral health. Significant modes of action of SnF2 in reducing DH are revealed. Finally, CP roughness measures provide indication of dentine lesions that may cause DH clinically.

Randomised clinical studies investigating immediate and short-term efficacy of an occluding toothpaste in providing dentine hypersensitivity relief

BackgroundDentine hypersensitivity (DH) can occur after gum recession or enamel loss and may impact quality of life. Treatments include toothpastes that decrease DH by occluding dentine tubules. One effective occluding ingredient used in toothpastes is stannous fluoride (SnF2), but this can be unstable in aqueous formulation. These three studies aimed to characterise the short-term effects of an experimental, anhydrous SnF2 dentifrice on DH.MethodsThree examiner-blind, parallel-group studies evaluated DH in participants with the condition after a single brushing and after 3d brushing with an experimental anhydrous 0.454% SnF2/polyphosphate toothpaste (Test) or a toothpaste containing 0.76% sodium monofluorophosphate (Control). Test treatment participants brushed two pre-identified sensitive teeth first, then their remaining dentition for ≥1 min (‘focused brushing’). Control treatment participants brushed their whole dentition for ≥1 min. DH was measured after single brushing and after 3d twice-daily use, via evaporative (air) (Schiff Sensitivity Scale) and tactile (Yeaple probe) stimuli and analysed using an ANCOVA model.ResultsIn all studies, after 3d treatment, the Test toothpaste/brushing regimen significantly reduced DH compared to the Control regimen by both evaporative and tactile stimuli assessment (p < 0.0001 for all). The Test regimen also significantly reduced DH from baseline at both time-points by both measures in all studies (p < 0.0001 for all).Mean Schiff sensitivity score differences (95% confidence intervals) between Test and Control regimens after 3d were: Study 1: − 0.45 (− 0.577, − 0.319); Study 2: − 0.40 (− 0.505, − 0.300); Study 3: − 1.31 (− 1.500, − 1.128). Mean tactile score differences were: Study 1: 11.30 (7.927, 14.662); Study 2: 3.57 (2.531, 4.614); Study 3: 24.54 (20.349, 28.736). After single use, in Studies 2 and 3, the Test toothpaste/brushing regimen significantly reduced DH versus Control by both measures (p < 0.001 for all); in Study 1, treatment differences were not significant. Toothpastes were generally well-tolerated.ConclusionsTaken together, these studies indicated focused brushing with an experimental anhydrous 0.454% SnF2/polyphosphate toothpaste reduces DH compared to brushing with a conventional toothpaste after single use, with greater reduction after 3d.Trial registrationRegistrations at ClinicalTrials.gov: Study 1: NCT02832375 (registered 26.July.2016); Study 2: NCT02731833 (registered 26.April.2016); Study 3: NCT02923895 (registered 5.October.2016).

Effect of stannous fluoride and zinc phosphate dentifrice on dental plaque and gingivitis: A randomized clinical trial with 6-month follow-up

ObjectiveThe objective of this study was to compare a stabilized stannous fluoride (SnF2) dentifrice with zinc phosphate (Colgate TotalSF) with SnF2 with zinc lactate and control fluoride dentifrices for gingivitis and plaque control over a 6-month period. MethodsA total of 135 adult participants were enrolled in this study. After randomization and blinding of examiners and patients, enrolled participants were provided instructions for use of assigned dentifrice. At 3 visits (0, 3, and 6 months), various gingival and plaque indexes were collected to determine the clinical efficacy of a stabilized SnF2 dentifrice. These results were compared with a SnF2 with zinc lactate dentifrice and with a control fluoride dentifrice. ResultsA total of 135 participants completed the study. All groups reported statistically significant reductions in gingival inflammation and improvement in plaque control at 3- and 6-month follow-up. Both SnF2 dentifrices showed statistically significant reductions in all indexes compared with the control dentifrice (P < .001). However, the test dentifrice showed higher but nonsignificant improvements in plaque and gingival indexes compared with the other SnF2 dentifrice. ConclusionsThis study reports similar efficacy of a test dentifrice to a commercial SnF2-containing dentifrice for plaque control and reduction in gingival inflammation and provides supporting evidence that the test dentifrice maintains its clinical efficacy with change of formulation. Practical ImplicationsThis newly formulated SnF2 stabilized with zinc phosphate dentifrice may be of benefit to patients in controlling plaque biofilm and gingivitis.

Evaluation of a stabilized stannous fluoride dentifrice on dental plaque and gingivitis in a randomized controlled trial with 6-month follow-up

BackgroundThe objective of this study was to compare a stannous fluoride (SnF2) dentifrice (Colgate TotalSF) stabilized with zinc phosphate with a sodium fluoride control dentifrice for gingivitis and plaque control over a 6-month period. MethodsOne hundred adult participants were enrolled in this study conducted in Chengdu, China. After random assignment and blinding of examiners and patients, enrolled participants received instructions for use of the assigned dentifrice. At 3 visits (baseline and 3 and 6 months), the authors measured various gingival and plaque indexes to determine the clinical efficacy of the stabilized SnF2 dentifrice compared with those of the control fluoride dentifrice (2 groups). ResultsNinety-eight participants completed the study. Both groups (test and control) had statistically significant reductions in gingival inflammation and improvement in plaque control at the 3- and 6-month follow-ups. In addition, the test dentifrice showed statistically significant reductions in all indexes compared with the control dentifrice (P < .001). ConclusionsThis study’s results show statistically significantly improved clinical outcomes for reduction of gingival inflammation and improvement in biofilm control over a 6-month period through the use of a SnF2 dentifrice stabilized with zinc phosphate when compared with results with a fluoride control dentifrice. Practical ImplicationsThis newly formulated dentifrice improves gingival health and plaque control and thereby may aid patients in attaining improved oral health.

Protective effects of SnF2 – Part II. Deposition and retention on pellicle-coated enamel

Deposition of an acid-resistant barrier onto enamel represents a potentially superior means for delivering protection against dietary, erosive acid challenges. The purpose of this study was to demonstrate the ability of a stabilised stannous fluoride (SnF2 ) dentifrice to: (1) deposit a SnF2 barrier layer onto pellicle-coated enamel surfaces; (2) increase the intensity of the barrier layer over time; and (3) be retained on the enamel surface for hours after product use. Squares of human enamel were exposed to pooled saliva for 1 hour (pellicle formation) and separated into six sets. Set 1 was treated with the supernatant of a 1:3 slurry of the test dentifrice (Crest(®) Pro-Health(®) : water for 2 minutes), then rinsed. Set 2 was treated in the same manner and then placed into saliva (6 hours). Set 3 was cycled through seven repeated treatments. Set 4 was treated for seven cycles and then placed into saliva (6 hours). Set 5 was a water control, and set 6 was a water control that remained in saliva for 6 hours. Surface analysis of specimens was done using laser ablation Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). Deposition of a barrier layer was demonstrated, beginning with the initial treatment, with Sn (using isotopes (117) Sn + (120) Sn) measured on the enamel surface as the reference marker. Deposition of the barrier layer was greater after seven cycles, and the retention of this layer was highly significant (P = 0.05, anova: 6 hours). This study confirms that: (1) the stabilised SnF2 dentifrice deposits a barrier layer onto the enamel surface, beginning with the first use of the product; (2) this barrier is enhanced following multiple treatments; and (3) the barrier layer is retained on the enamel surface for hours after product use.

Protective effects of SnF2 – Part I. Mineral solubilisation studies on powdered apatite

To compare the ability of two active ingredients - sodium fluoride (NaF) and stannous fluoride (SnF2 ) - to inhibit hydroxyapatite (HAP) dissolution in buffered acidic media. Two in vitro studies were conducted. HAP powder, which is representative of tooth mineral, was pretreated with: test solutions of NaF or SnF2 , 10 g solution per 300 mg HAP powder (Study 1); or NaF or SnF2 dentifrice slurry supernatants, 20 g supernate per 200 mg HAP powder for 1 minute followed by three washes with water, then dried (Study 2). About 50 mg of pretreated HAP was exposed to 25 ml of acid dissolution media adjusted to and maintained at pH 4.5 in a Metrohn Titrino reaction cell. Exposure of HAP to the media results in dissolution and release of hydroxide ion, increasing the pH of the solution. The increase in pH is compensated for by automatic additions of acid to maintain the original pH (4.5) of the reaction cell. Total volume of titrant added after 30 minutes was used to calculate the percentage reduction in dissolution versus non-treated HAP control. Both F sources provided protection against acid dissolution; however, in each study, SnF2 -treated HAP was significantly more acid-resistant than the NaF treated mineral. In study 1, at 280 ppm F, representing concentrations of F found in the mouth after in vivo dentifrice use, the reduction in HAP dissolution was 47.7% for NaF and 75.7% for the SnF2 -treated apatite (extrapolated). In study 2, the reduction in HAP dissolution was 61.3% for NaF and 92.8% for SnF2 -treated samples. Differences in percentage reduction were statistically significant (Paired-t test). Results of these studies demonstrate that both of the fluoride sources tested enhance the acid resistance of tooth mineral and that resistance is significantly greater after treatment with SnF2 compared with treatment of tooth mineral with NaF.

In situ clinical evaluation of a stabilised, stannous fluoride dentifrice

To compare the erosion protection efficacy of a stabilised, stannous fluoride (SnF2 ) dentifrice versus a sodium fluoride (NaF) dentifrice using a modified in situ clinical model. This study, a randomised parallel group in situ design with in vivo product use and ex vivo acid challenge, compared: A, a dentifrice containing 1,450 ppm F as NaF; B, a dentifrice containing 1,450 ppm F (1,100 ppm F as SnF2 + 350 ppm F as NaF); and T, tap water. Sample size was n = 4 per group (total of 12 subjects) and within each subject appliances were placed on each side of the mouth (left and right). Enamel specimens were placed in different positions of the mouth (front, mid-front, mid-rear, rear) in each appliance (total = 8 specimens per subject). Product treatment was twice per day (lingual brushing for 30 seconds followed by swishing for 90 seconds with the resultant product/saliva slurry) in vivo for 15 days, and ex vivo acid treatment (0.02 m citric acid 5 minutes four times per day; total exposure time = 300 minutes). Data were analysed using a general linear repeated measures model with treatment, side and position as fixed effects. Within subjects, correlations were modelled assuming a different correlation and variance for treatment B relative to the other groups. Pairwise treatment differences were performed using a 5% two-sided significance level. Enamel loss (in μm) was significantly lower (P < 0.005) for treatment B versus treatments A and T. Treatment B reduced enamel surface loss by 86.9% relative to treatment A. There was no statistical difference in mean enamel loss (P = 0.51) between treatments A and T. Enamel loss was not statistically different for side (left vs. right; P = 0.44) or position (front, mid-front, mid-rear, rear; P = 0.36). This modified in situ erosion model confirmed the enhanced erosion protection benefits of a stabilised SnF2 dentifrice versus a conventional NaF dentifrice, validating the ability of the model to safely and effectively demonstrate differences in the erosion protection potential of oral care products.

Protective effects of SnF2 – Part III. Mechanism of barrier layer attachment

To assess the ability of various fluoride salts to protect enamel against acid attack via a barrier mechanism. Extracted human enamel specimens were cleaned and rinsed, then soaked in pooled human saliva for 1 hour to initiate formation of an early pellicle. Groups of three specimens each were etched for 10 minutes in 1% citric acid (pH 2.3), treated in a 1:3 slurry of dentifrice [1,100 ppm F as stannous fluoride (SnF2 ), 1,100 ppm F as sodium fluoride (NaF), 1,000 ppm F as sodium monofluorophosphate (SMFP), or 1,400 ppm F as amine fluoride (AmF)] and saliva for 2 minutes, exposed to 2% alizarin red-S (a calcium-selective dye) and rinsed again. The relative ability of each test product to deposit a barrier layer on the enamel surface was measured by its ability to protect against attachment of the calcium-selective dye. Specimens treated with the SnF2 dentifrice showed the least dye attachment, indicating a high level of surface protection. On a five-point scale, with 0 being no dye deposition (100% protection) and four being complete dye coverage (0% protection), the SnF2 -treated specimens scored an average of 0.25, with NaF scoring 3.4, SMFP scoring 3.4 and AmF scoring 3.7. Protection of the enamel surface was significantly higher for the SnF2 product than for the other products (P < 0.05), with no significant differences among the other three F salts. These results demonstrate that after an aggressive acid challenge, SnF2 deposits a barrier layer onto the pellicle-coated enamel surface, and the barrier layer which attaches onto acid challenged tooth surfaces is different from any that might be provided by treatment with the other fluoride compounds tested.

Comparative Efficacy of Stabilized Stannous Fluoride/Sodium Hexametaphosphate Dentifrice and Sodium Fluoride/Triclosan/Copolymer Dentifrice for the Prevention of Periodontitis in Xerostomic Patients: A 2‐Year Randomized Clinical Trial

The primary objective of this study was to compare the efficacy of a stannous fluoride (SnF2) dentifrice relative to a positive control triclosan dentifrice for prevention of clinical attachment loss (CAL) in xerostomic patients. A secondary objective was to compare the dentifrices for root caries remineralization. This was a 2-year, randomized, double-masked, parallel-group study. A 0.454% SnF2/sodium hexametaphosphate dentifrice was tested versus a positive control dentifrice (sodium fluoride/0.30% triclosan/copolymer) in 440 medication-induced xerostomic adults identified in a 1-year, run-in phase (no treatment) as high risk for periodontitis and root caries. During the study phase, subjects were stratified based on gender and attachment level into two groups. Subjects brushed twice a day for 60 seconds using their assigned product. Clinical examinations including probing depth, attachment level, bleeding on probing, and root caries remineralization were performed at baseline and 1 and 2 years. A total of 334 subjects were evaluable. During run-in, average CAL relative to initial examination was 1.33 mm. Probing depth increased 0.95 mm. At year 2 in the treatment phase, attachment gain was 0.77 mm for the test group and 0.79 mm for the control group versus baseline. Probing depth decreased 0.57 mm for the test group, similar to the control group (0.53 mm). These changes versus baseline were statistically significant (P <0.01) for each group. Products were not statistically significantly different from each other. Both treatments resulted in similar remineralization for root caries lesions at study completion (P = 0.40). The results establish comparable benefits for the SnF2 dentifrice in preventing CAL and root caries versus the sodium fluoride/triclosan/copolymer control in xerostomic patients.

フッ化物局所応用ならびに飲料水中フッ素による永久歯う蝕予防効果の比較

The purpose of this study was to compare the caries prevalence and incidence between 6-year-old lifelong residents in a natural fluoride area (0.74-1.10ppm F: NF group) and participants in school-based fluoride mouthrinsing (FR group) or usage of SnF2 dentifrice (FD group). The FR group rinsed daily with 0.05% NaF solution for 3.5 years and the FD group used 0.41% SnF2dentifrice for 3 years beginning at the age of six.Mean DMFT in the NF group (n=58) from the age of 6 to 9 was significantly lower (p<0.05, p<0.01) than that of both the FR (n=78) and the FD group (n=73) at all of the ages examined. Only 1-year mean DMFT increments from the age of 6 to 7 in the NF group (0.24±0.67) were significantly different (p<0.01) from the FR group (0.67±0.98) and the FD group (0.71±0.89). No statistical differences of mean DMFT increments, however, were found between any pairs of study groups after 2 or 3 years from the baseline. Incremental DMFT rates on first molars in the NF group were significantly lower (p<0.05, p<0.001) than those in the FR or FD group both after 1 and after 2 years.The results of the present study demonstrate that lifelong residents in a natural fluoride area experienced significantly fewer caries than those who received topical fluoride application. However, the differences of caries increments between the FW group and the FR or FD groups diminished with the passage of time.

Plasma fluoride levels in man following intake of SnF2 in solution or toothpaste.

The degree and rate of fluoride absorption in five volunteers were studied after ingestion of SnF2 and NaF solutions or SnF2 toothpaste. The fluoride concentration in plasma was followed for eight hours. The relative bio-availability of fluoride was calculated and was similar for both the NaF and SnF2 solutions, although the latter solution showed a somewhat faster absorption rate. The bio-availability of fluoride from the SnF2 dentifrice was 85%.

Caries-preventive effect of a stannous fluoride dentifrice containing sodium phytate in hamsters

The effect of a new preparation of the stannous fluoride dentifrice on dental caries development was examined in an animal caries model.Golden hamsters aged 27 days were intraorally infected with cariogenic Streptococcus mutans K1-R and reared on the caries-inducing diet #2000 for 32 days. During the experimental period, the molars of the animals were brushed for 1 min. once a day, 5 days a week, with a 0.41% stannous fluoride dentifrice containing 0.88% sodium phytate, a 0.41% stannous fluoride dentifrice alone, or a placebo dentifrice. At the end of the experiment, the animals were killed, and plaque accumulation and lesions on the molars were evaluated.Daily application of the SnF2-phytate dentifrice significantly inhibited caries development and plaque formation; when compared to the placebo dentifrice-treated group, the SnF2-phytate dentifrice-treated group showed 49.2% reduction of caries development, which was much greater than the 32.2% reduction in the SnF2 dentifrice group. Similarly, reduction of plaque formation was 24.5% for the SnF2-phytate dentifrice group and 8.5% for the SnF2 dentifrice group.The high caries-inhibitory and plaque-inhibitory capacities of the SnF2-phytate dentifrice may be due to the synergistic enhancement of both the acid resistance of enamel and the anti-plaque action exerted by combination of the curative ingredients, fluoride, stannous and phytate ions.