OBJECTIVE: To compare the effectiveness of using a 0.454% stannous fluoride-containing dentifrice twice daily in relieving dentinal hypersensitivity (DH) in a Chinese population.
METHODS: This was a single-centre, randomized, controlled, examiner-blind, three-treatment-arm, parallel-group study in participants with clinically diagnosed DH. Subjects who met inclusion criteria (n = 197) were randomly allocated into 3 groups: test group (n = 66)-using a 0.454% stannous fluoride-containing dentifrice twice daily; positive control group (n = 64)-using a 5.0% calcium sodium phosphosilicate-containing dentifrice twice daily; negative control group (n = 67)-using a 1150 ppm of NaF dentifrice twice daily. Status of DH was assessed at week 4 and week 8 by the same independent examiner. Changes from baseline in Schiff sensitivity score, tactile threshold and Dentine Hypersensitivity Experience Questionnaire (DHEQ) score were analysed using analysis of covariance models. The DHEQ evaluated subject-perceived oral health-related quality of life (OHRQoL).
RESULTS: Statistically significant improvements in mean Schiff scores (p < 0.0001 for all products at Weeks 4 and 8), tactile threshold (p < 0.0001 for test and negative control at Weeks 4 and 8: Week 4 p = 0.0040 and Week 8 p < 0.0001 for positive control) and all DHEQ scores (p < 0.01 for all groups) were observed. No statistically significant differences were observed in the adjusted mean between all dentifrices at both timepoints, potentially driven by a placebo effect. Forty-two treatment-emergent adverse events (TEAEs) were reported (n = 32 subjects), with 2 serious AEs (n = 1) in the test group. TEAEs were not considered treatment-related.
CONCLUSIONS: All groups demonstrated statistically significant improvements in Schiff score, tactile threshold and OHRQoL. However, due to a possible placebo effect in the negative control, there were no statistically significant differences between the dentifrices.
CONCLUSIONS: This study adds to the growing research exploring why the placebo effect is a common phenomenon in DH studies.
BACKGROUND: ClinicalTrials.gov Identifier: NCT04950465.

The use of silver fluoride followed by stannous fluoride was designed for the treatment of open carious lesions in primary molars in dental outreach programs. However, during the COVID-19 pandemic when aerosol-producing procedures were inadvisable, one dental location started using it as the first stage in a two-visit restorative procedure for carious primary molars. If the gap between the fluoride application and the restoration placement stages was around 3-5 weeks it was noticed that a black friable crust appeared on the caries surface. To investigate further a normally discarded crust from one patient was retrieved and sent for analysis.
Two techniques suitable for identification and preliminary analysis of material of unknown composition, scanning electron microscopy and energy dispersive spectroscopy (EDS) were used. The only preparation was that the specimen was dried and coated beforehand.
This preliminary examination showed two unexpected findings. The first was that the crust surface indicated a possible dentine derivation as it was covered with reasonably evenly spaced holes. In addition, the EDS spectrum showed it to be, at least, partially mineralized. The second unexpected finding was that the surface was coated with electron-dense particles. The size of the particles and the EDS spectrum pointed to the likelihood of the majority of them being nanosilver. These unexpected findings suggest a possible new direction for research.

To assess the effect of different tin-containing toothpastes on the control of erosive tooth wear in enamel and dentin.
Enamel and dentin slabs were randomly distributed into 7 experimental groups (n = 10/substrate): C-: negative control (Artificial saliva); AmF (regular fluoridated toothpaste without tin); Sn-1 (SnF2/NaF); Sn-2 (SnF2/NaF/SnCl2); Sn-3 (SnCl2/NaF); Sn-4 (SnF2/SnCl2); Sn-5 (SnCl2/AmF/NaF/chitosan). Specimens were submitted to 5-day erosion-abrasion cycling. Surface loss (SL) was determined with an optical profilometer. Tin deposition on the tooth surfaces and some characteristics of the toothpastes (pH, potentially available F-, %weight of solid particles, and RDA) were also assessed. Data were statistically analyzed (α = 0.05).
For enamel, the Sn-2 presented the lowest SL, not differing significantly from AmF, C+, and Sn-3. The SL of these groups was significantly lower than the C-, except for Sn-3. Sn-1 and Sn-4 were also not significantly different from C-. For dentin, C- significantly showed the highest SL values, whilst, Sn-1 presented the lowest SL, not differing significantly from AmF, Sn-2, C+, and Sn-3. There was a significant positive association between enamel SL and the pH and tin deposition. Dentin SL was significantly negatively associated with the %weight of solid particles and RDA.
Most of the tin-toothpastes were able to exhibit some protection against ETW. In this process, the toothpastes characteristics play a role, as lower enamel SL was significantly associated with lower pH values and tin deposition; and lower dentin SL was associated with higher %weight of solid particles and RDA of the toothpastes.
Tin-containing toothpastes can be used for erosive tooth wear protection, but our study showed that their effect depends on the pH, amount of tin deposition, % weight of solid particles and RDA of the toohpastes.

To compare the remineralisation efficacy and ion bioavailability of two novel SnF2-containing dentifrices in a blinded, cross-over, randomised in situ clinical study.
Six participants wore removal palatal appliances holding human enamel and dentine blocks with subsurface lesions. Appliances were worn for two treatment periods of 14 consecutive days each, with a one-week washout period in-between. Participants were randomly allocated to rinse with a 1:5 diluted coded slurry of one of two dentifrices containing either 5 % casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) +1100 ppm F as SnF2 [MIPOP], or 1100 ppm F as SnF2 [CT], for 1 min, four times a day. Saliva was collected post-treatment and analysed for tin, calcium, inorganic phosphate and fluoride ions using atomic absorption spectrophotometry and ion chromatography. Enamel and dentine lesions were analysed for percent remineralisation (%R) using transverse microradiography and percent surface microhardness recovery (%SMHR).
MIPOP released significantly higher F (3.00 ± 0.27 mM), Ca (15.23 ± 3.23 mM) and Sn (1.18 ± 0.13 mM) into saliva whereas CT released 2.89 ± 0.32 mM F and only 0.84 ± 0.11 mM Ca and 0.28 ± 0.10 mM Sn. MIPOP produced significantly higher %R than CT: 25.6 ± 1.5 % compared to 15.2 ± 0.7 % in enamel, and 33.6 ± 3.1 % compared to 20.6 ± 1.1 % in dentine. Additionally, MIPOP produced significantly higher %SMHR (18.2 ± 7.9 %) compared to CT (4.1 ± 0.6 %).
Both dentifrices promoted remineralisation, but the MIPOP dentifrice with added CPP-ACP and the ion-stabilising effects of CPP released higher amounts of bioavailable tin and produced significantly higher remineralisation and surface microhardness recovery.
Modern dentifrices contain SnF2 for a range of oral health benefits. Challenges associated with stability of these formulations can affect ion bioavailability, reducing efficacy. Two dentifrices with SnF2 promoted remineralisation in situ, however the dentifrice with the added saliva biomimetic CPP-ACP was superior and therefore may produce greater health benefits.

BACKGROUND: The aim of this in vitro study was to assess the suitability of high-resolution time-of-flight secondary ion mass spectrometry (ToF-SIMS) for visualizing cross-sectional changes in human enamel microstructure and chemical composition during treatment and remineralization cycling of artificially generated caries lesions underneath an artificial plaque.
METHODS: Treatments consisted of exposure to twice daily toothpaste/water slurries prepared from 0, 1,100, and 5,000 μg/g fluoride (F) NaF/silica toothpastes. In addition, treatments with slurries prepared from 1,100 μg/g F SnF2/silica toothpastes were done using 44Ca in the remineralization solution to allow for differentiation of newly formed mineral and exploration of incorporated metal dopants using ToF-SIMS. Complementary microhardness, scanning electron microscopy, and high-resolution transmission electron microscopy (HR-TEM) investigations were performed on enamel cross sections.
RESULTS: HR-TEM was used for the first time to determine the change in crystallinity during remineralization revealing distinct microstructural zones within one lesion. Chemical mapping using ToF-SIMS demonstrated that the distribution of F, while observed primarily in the new mineral phase, was widespread throughout the lesion with 44Ca substantially limited to the remineralizing mineral. Both penetrated the inter-rod spaces of the sound enamel illustrating how acid damage propagates into the native mineral as the caries lesion deepens. HR-TEM examination revealed different regions within the lesion characterized by distinct micro- and ultrastructures. Importantly, HR-TEM revealed a return of crystallinity following remineralization. F dose-response observations verified the ability of these high-resolution techniques to differentiate remineralization efficacy.
CONCLUSIONS: The collective results provided new insights such as the visualization of F or calcium penetration pathways, as well as new tools to study the caries process.

BACKGROUND: Erosive tooth wear is a highly prevalent dental condition that is modified by the ever-present salivary pellicle. The aim of the present in situ study was to investigate the effect of polyphenols on the ultrastructure of the pellicle formed on dentin in situ and a subsequent erosive challenge.
METHODS: The pellicle was formed on bovine dentin specimens for 3 min or 2 h in 3 subjects. After subjects rinsed with sterile water (negative control), 1% tannic acid, 1% hop extract, or tin/fluoride solution containing 800 ppm tin and 500 ppm fluoride (positive control), specimens were removed from the oral cavity. The erosive challenge was performed on half of the specimens with 1% citric acid, and all specimens were analyzed by transmission electron microscopy. Incorporation of tannic acid in the pellicle was investigated by fluorescence spectroscopy.
RESULTS: Compared to the negative control, ultrastructural analyses reveal a thicker and electron-denser pellicle after application of polyphenols, in which, according to spectroscopy, tannic acid is also incorporated. Application of citric acid resulted in demineralization of dentin, but to a lesser degree when the pellicle was pretreated with a tin/fluoride solution. The pellicle was more acid-resistant than the negative control when modified with polyphenols or tin/fluoride solution.
CONCLUSIONS: Polyphenols can have a substantial impact on the ultrastructure and acid resistance of the dentin pellicle, while the tin/fluoride solution showed explicit protection against erosive demineralization.

OBJECTIVE: The purpose of the current study was to evaluate the impact of three various mouthwashes on the effectiveness of fluoride dentifrices in preventing enamel erosion.
METHODS: A total of 120 sound intact human premolar teeth which were extracted for orthodontic treatment were selected for the study. A 3 × 3 mm window section was positioned in the middle of the coronal surface of the tooth in order to define the study area. Each sample was placed in a solution of 1% citric acid (pH 3.5) for 10 minutes in order to produce an eroded surface. All samples were divided into two main groups (60 samples each) as follows: Group A for sodium fluoride dentifrices and group B for stannous fluoride dentifrices, again it is subdivided into: CHX: Chlohex ADS®, EO: Listerine®, CPC: Colgate® Plax (20 samples in each subgroup). After that, samples underwent the pH cycling model for 5 days. Samples were examined for surface loss using a scanning electron microscope.
RESULTS: In sodium fluoride dentifrices group, before intervention, the surface loss was 3.12 ± 1.03 in CHX group, 3.08 ± 1.20 in EO group, and 3.09 ± 0.96 in CPC group. After intervention, the less surface loss found with CHX group (2.18 ± 0.84), followed by CPC (2.34 ± 0.74) and EO group (2.46 ± 0.97). In stannous fluoride dentifrices group, before intervention, the surface loss in CHX group was 3.26 ± 1.19, in EO group, it was 3.18 ± 1.31, and in CPC group, it was 3.22 ± 1.06. After intervention, the less surface loss found with CHX: group (1.90 ± 0.54), followed by CPC (2.24 ± 0.28) and EO group (2.38 ± 0.20).
CONCLUSIONS: The present study concluded that the fluoride dentifrices\' preventive effects against tooth surface loss were unaffected by a different mouthwashes with varying compositions and major constituents. In terms of erosion, fluoridated toothpaste containing stannous fluoride was found to provide better surface loss protection than sodium fluoride.
CONCLUSIONS: Primary prevention and the eradication of contributing causes are the greatest strategies for preventing erosion. Simultaneously, antibacterial agent in the mouthwashes may help in enhancing the effect of fluoride in the enamel, owing to their high affinity for teeth structures. Therefore, in addition to cause-related treatment, further efforts to reduce tooth tissue loss are also necessary.

Gels containing juca seed galactomannan (JSG) were evaluated for their potential to prevent the progression of dentin erosive wear in an in vitro study with four experimental groups (n = 9). The treatments included distilled water (DW), 0.05% stannous fluoride (121 ppm F), and 0.5% or 1% JSG. The specimens underwent a cycle (3 times/day) consisting of immersion in 1% citric acid (5 minutes), treatment (5 minutes), and artificial saliva exposure (2 hours/overnight) for 5 days. Surface changes were assessed using mechanical profilometry (wear), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The data were analyzed using ANOVA followed by Tukey\'s post-test (p < 0.05). The negative control group exhibited the highest wear (6.0 µm ± 3.5), significantly differing from the group treated with 0.05% stannous fluoride gel (p = 0.007), which showed less dentin loss. The groups treated with 0.5% and 1% JSG showed results similar to the negative control (p = 0.661; p = 0.212, respectively) and the stannous fluoride group (p = 0.103; p = 0.379, respectively). In the SEM images, the specimen treated with stannous fluoride showed obliterated tubules, while the JSG gels formed crystals on the dentin surface, as confirmed by the presence of oxygen and calcium in the EDS analysis. Although the JSG gels showed similar results to the stannous fluoride, did not exhibit superior efficacy at the tested concentrations.

UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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).
UNASSIGNED: 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.
UNASSIGNED: 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.

BACKGROUND: Stannous fluoride dentifrice is well established for its beneficial clinical effects. In this study, we evaluated the effects of stannous fluoride on inflammation and oral microbiome.
METHODS: In this randomized, parallel-arm, double-blind, controlled clinical trial, we compared clinical resolution of experimental gingivitis by evaluating bleeding on probing, gingival index, and plaque index between stannous fluoride stabilized with zinc phosphate (test) and sodium fluoride (control) dentifrices. Further, these groups were compared for oral neutrophil counts, systemic priming of neutrophils, gingival crevicular fluid (GCF) expression of inflammatory markers, and the oral microbiome.
RESULTS: We found significant reduction in bleeding on probing in the test group compared to the control group in experimental gingivitis when participants used the test dentifrice prior to induction of experimental gingivitis. The test group also showed significant reductions in GCF levels of inflammatory markers (matrix metalloproteinase 8 [MMP8], receptor activator of nuclear factor kappa-Β ligand [RANKL]), oral polymorphonuclear neutrophil (PMN) counts, and systemic neutrophil priming (CD11b expression) during experimental gingivitis. Further, significant reductions in the gram-negative genera Porphyromonas, Tannerella, and Treponema were noted in the test group.
CONCLUSIONS: The stannous fluoride stabilized with zinc phosphate dentifrice formulation demonstrated clinical reduction in gingival inflammation and a beneficial effect on microbiome and immune markers. This intervention should be explored as a preventive aid in the progression of plaque-induced gingivitis to periodontitis.