Antibacterial effects of dentifrices against Streptococcus mutans in children: a comparative in vitro study.

Fluoridated dentifrices have antibacterial effects on children's teeth. On the other hand, the side effects encountered with the use of them have led researchers to look for safe alternatives. This study aimed to determine the antibacterial effect of different commercially available fluoride-free dentifrices on Streptococcus mutans (S. mutans) in comparison with different concentrations of fluoridated dentifrices. Study groups comprised of fluoride-free dentifrices, which contain Probiotic (Activated Charcoal Probiotic Dentifrice-Group P), Aloe Vera-Group AV and Salivary Proteins-Group SP. Fluoridated dentifrices containing 1450 ppm fluoride-Control Group 1 and 500 ppm fluoride-Control Group 2 served as control groups. Antibacterial activity was assessed by Minimum Inhibitory Concentrations and agar well diffusion assays on S. mutans. Biofilm inhibition assay was performed with dentifrices, which had antibacterial activities, and a negative control phosphate-buffered saline (Group PBS) on sterile hydroxyapatite discs against S. mutans. Statistical evaluation was performed. Only group AV showed an antibacterial effect on S. mutans, while control groups showed a similar antibacterial effect. The mean number of viable bacteria present in S. mutans biofilm in Control Group 1 and 2 and Group AV were statistically significantly lower than that in Group PBS, but there were no statistically significant differences between Control Groups and Group AV. Antibacterial activity of commercial dentifrices against S. mutans may be exerted by antibacterial components other than fluoride. Aloe vera-containing toothpaste showed an antibacterial effect on S. mutans, although not as much as the fluoride-containing toothpastes in the control groups. However, further in vivo and long-term studies are required.

Remineralization potential of dentifrices with calcium sodium phosphosilicate and functionalized tri-calcium phosphate in the deeper incipient carious lesions: An in vitro study.

OBJECTIVES: This study evaluated the remineralization potential of calcium sodium phosphosilicate and functionalized tri-calcium phosphate (f-TCP) dentifrices in deeper incipient carious lesions (ICLs). MATERIALS AND METHODS: Artificial ICLs were created by placing premolars into demineralizing solutions. Teeth were randomly assigned into four groups: calcium sodium phosphosilicate (Group 1), f-TCP (Group 2), 1450 ppm fluoride (Group 3), and distilled water (Group 4), which were subjected to 10-day pH cycling. Mineral density (MD) was assessed using microcomputed tomography (Micro-CT), while hardness (H) and elastic modulus (EM) were assessed using nanomechanical testing. RESULTS: MD % gain was higher in Groups 1-3 than in Group 4. In addition, Groups 1 and 2 exhibited significantly higher MD % gain than Group 3. Also, Groups 1-3 showed significantly higher EM and H values than Group 4 in the outer enamel area; yet, Groups 1 and 2 displayed significantly higher EM and H values than Groups 3 and 4 in the inner enamel. CONCLUSIONS: The MD, EM, and H of ICLs significantly increased with the addition of calcium sodium phosphosilicate or f-TCP to fluoridated dentifrices compared to standard fluoride dentifrices. The added active ingredients remineralized the deeper parts of the ICLs, while remineralization at the lesion surface was similar between tested dentifrices.

Influence of the combined effect of desensitizing dentifrices and universal adhesives on dentin bond strength under erosive conditions.

OBJECTIVE: This study aimed to evaluate whether the use of desensitizing dentifrices containing obliterating agents can affect bond strength of eroded/abraded dentin. METHODOLOGY: A total of 100 dentin samples were obtained from human molars. The teeth were cut into 3 mm-thickness discs and allocated in five groups (n=20), according to the toothpaste used: WoF - abrasion with fluoride-free toothpaste (Cocoricó); Arg - toothpaste containing arginine (Colgate Sensitive Pro-Relief); Nov - calcium sodium phosphosilicate toothpaste (Sensodyne Repair and Protect); SnF - fluoride-containing toothpaste (AmF/SnCl2/SnF2 - Elmex Erosion); and Control (no erosive/abrasive process). The erosive/abrasive cycle consisted of immersion in citric acid (1%, pH 2.6, 5 min, 4×/day) and abrasion (2×/day, 120-20 sec abrasion, 100 sec immersion) with each toothpaste. During intervals, samples were immersed in artificial saliva. This cycle was performed for five days. Two resin cylinders (2 mm in diameter) were constructed on each sample for the shear bond strength test using a universal adhesive system. The self-etch and etch-and-rinse (Scotchbond Universal) strategies were employed, each in half of the total sample (n=10). Bond strength (MPa) was measured in a shear test and failure modes were assessed with a stereomicroscope. Statistical analysis was performed using the two-way analysis of variance (ANOVA) and Tukey tests (p<0.05). RESULTS: A statistically significant difference was found between the adhesive strategies tested (p<0.001), with the self-etching form showing higher values than the etch-and-rinse. Moreover, no significant differences were observed between the tested toothpastes (p=0.750) and interactions (p=0.438). CONCLUSION: The use of toothpaste containing obliterating agents does not affect bond strength to dentin subjected to erosive/abrasive conditions when a universal adhesive is used. However, the self-etch strategy might be preferred for eroded/abraded dentin.

CO2 laser irradiation combined with fluoridated dentifrice improved its protective effect on caries lesion progression regardless of the acidulated phosphate fluoride gel application: An in situ study.

OBJECTIVE: This in situ study aimed to investigate the efficacy of CO2 laser at a 10.6-µm wavelength combined with 1.23% acidulated phosphate fluoride (APF) and fluoridated dentifrice with 1100 µg F/g (FD) to control enamel caries progression. MATERIALS AND METHODS: Sixteen volunteers wore palatal appliances containing eight demineralized enamel specimens for four 14-day phases under sucrose exposure. These specimens were submitted to CO2 laser irradiation and APF alone or combined with FD. Treatment groups were non-fluoridated dentifrice-NFD, NFD + CO2 laser, NFD + APF, NFD + CO2 laser + APF, FD, FD + CO2 laser, FD + APF, and FD + CO2 laser + APF. Mineral loss, calcium fluoride (CaF2), fluorapatite (FAp), and fluoride in the biofilm were analyzed by analysis of variance followed by the Student-Newman-Keuls test, p < 0.05. RESULTS: The highest mineral loss inhibition was noted when FD and CO2 laser irradiation were combined, which did not significantly differ from the FD + CO2 laser + APF group. The CaF2, FAp, and F in the biofilm were more pronounced when the FD and APF were combined. The CO2 laser irradiation promoted a slightly higher concentration of CaF2 in the enamel and F in the biofilm. CONCLUSION: Although APF promotes the high formation of CaF2 and FAp, the combined use of FD with CO2 laser overcomes the APF effect in inhibiting the progression of artificial caries-like lesions in situ. CLINICAL SIGNIFICANCE: Under the in situ design of this study, remineralization of white spot lesions was achieved through CO2 laser irradiation and daily use of fluoridated dentifrice. Future clinical trials are encouraged to substantiate this finding.

Comparative evaluation of antibacterial efficacy of active oxygen containing versus other dentifrices against Streptococcus mutans count in children with early childhood caries: A clinico-microbiological study.

Background: Fluoridated dentifrices have been used for the prevention of dental caries since ages. However, to avoid the risk of fluorosis, the use of newer nonfluoridated options in dentifrices has shown a great interest in reducing Streptococcus mutans (SM) in early childhood caries (ECC). Aim: The study aimed to evaluate the antimicrobial efficacy of active oxygen (AO)-based dentifrice with amine fluoride (AF)-, sodium monofluorophosphate (SMP)-, herbal (HB)-, and tricalcium phosphate (TCP)-based dentifrices on SM count in children with ECC. Materials and Methods: Two hundred and fifty children aged 3-6 years with def ≥4 were selected and randomly divided into five groups of 50 each, based on the type of dentifrices used; Group I: AO-based, Group II: TCP, Group III: SMP, Group IV: AF, and Group V: HB dentifrice, and were asked to brush twice daily for 15 days. The saliva samples were collected at baseline, and after 15 days, cultured for SM colonies count. Results: Difference in colony-forming units (CFU)/ml between baseline and 15 days was highly significant in all the five groups (P < 0.001). Significant difference was observed in SM count after 15 days between Groups I and IV (P = 0.017), while nonsignificant differences were seen when compared with Groups II, III, and V (P = 0.975, 0.137, and 0.992). Conclusions: All the dentifrices were efficacious in reducing SM count in children with ECC. Although AO dentifrice showed superior results when compared to SMP, TCP, and HB, it did not prove to be superior to AF.

Direct and indirect effects of different dentifrices on the initial bacterial colonization of enamel in situ overnight.

OBJECTIVE: The aim of this study was to investigate the direct and indirect influence of fluoridated toothpastes and fluoride-free toothpaste with hydroxyapatite (HAP) as active ingredient on initial bacterial colonization on enamel in situ. METHODS: For this clinical-experimental pilot study, eight subjects were instructed to brush their teeth with three different toothpastes (Elmex® : 1400 ppm AmF, Meridol® : 1400 ppm AmF +SnF2, Karex® : HAP), using each for two consecutive days. As a control, brushing without toothpaste was performed. To evaluate bacterial colonization, subject wore splints with buccally placed bovine enamel platelets overnight. Two modes were tested. In a first pass (regimen A), the splints were inserted after toothbrushing to examine the indirect effects of the dentifrices. In order to investigate the direct effects, the specimens were brushed in situ in a second pass (regimen B). Biofilm formation was visualized and quantified using fluorescence microscopy (DAPI and BacLight) and transmission electron microscopy (TEM). RESULTS: For brushing regimen A (indirect effect of dentifrices), no statistical differences were detected between any of the tested dentifrices or the control. Likewise, no statistically significant differences were recorded for brushing regimen B (direct effect of dentifrices). Furthermore, no differences between the different brushing techniques were determined with regard to the ultrastructure of the overnight biofilm. CONCLUSION: Within the limitations of the present pilot study, it can be concluded that in patients with good oral hygiene, dentifrices and their chemical composition have no statistically significant effect on the initial bacterial colonization of enamel platelets in situ, irrespectively of the mode of application.

In vitro assessment of activated charcoal-based dental products.

OBJECTIVE: Assess the effects of activated charcoal-based products on whitening and changes on dental enamel surface. MATERIAL AND METHODS: Fifty-two blocks of bovine dental enamel were randomly distributed in four groups (n = 13): brushing with activated charcoal-based powder (PW); brushing with activated charcoal-based dentifrice (AC); brushing with a conventional dentifrice containing 1450 ppm of fluoride (CD); and whitening with 10% carbamide peroxide (CP). Color, microhardness, and surface alteration were analyzed at baseline and after 14 days of treatment. Three samples per group were randomly selected and examined using scanning electron microscopy (SEM) to analyze the morphology. RESULTS: PW exhibited greater color change for the ΔE00 , ΔWID, Δb* and ΔL* parameters than other groups (p < 0.05). After treatment, microhardness decreased in AC and CP groups (p < 0.05). Also, PW and AC groups showed more surface alteration than CD and CP (p < 0.001). Changes in the morphology of dental enamel were observed by SEM in PW and AC groups. CONCLUSION: Activated charcoal-based products showed a lower whitening effect than 10% carbamide peroxide. These products also influenced dental enamel microhardness, resulting in greater surface alteration. CLINICAL SIGNIFICANCE: Activated charcoal-based products promoted minimum whitening effects with significant enamel surface alteration. The 10% carbamide peroxide was more effective for whitening and caused slight enamel surface alteration.

A Combination of Zinc and Arginine Disrupt the Mechanical Integrity of Dental Biofilms.

Mechanical cleaning remains the standard of care for maintaining oral hygiene. However, mechanical cleaning is often augmented with active therapeutics that further promote oral health. A dentifrice, consisting of the "Dual Zinc plus Arginine" (DZA) technology, was found to be effective at controlling bacteria using in vitro laboratory studies, translating to clinical efficacy to deliver plaque and gingivitis reduction benefits. Here, we used biophysical analyses and confocal laser scanning microscopy to understand how a DZA dentifrice impacted the mechanical properties of dental plaque biofilms and determine if changes to biofilm rheology enhanced the removal of dental plaque. Using both uniaxial mechanical indentation and an adapted rotating-disc rheometry assay, it was found that DZA treatment compromised biofilm mechanical integrity, resulting in the biofilm being more susceptible to removal by shear forces compared to treatment with either arginine or zinc alone. Confocal laser scanning microscopy revealed that DZA treatment reduced the amount of extracellular polymeric slime within the biofilm, likely accounting for the reduced mechanical properties. We propose a model where arginine facilitates the entry of zinc into the biofilm, resulting in additive effects of the two activities toward dental plaque biofilms. Together, our results support the use of a dentifrice containing Dual Zinc plus Arginine as part of daily oral hygiene regimens. IMPORTANCE Mechanical removal of dental plaque is augmented with therapeutic compounds to promote oral health. A dentifrice containing the ingredients zinc and arginine has shown efficacy at reducing dental plaque both in vitro and in vivo. However, how these active compounds interact together to facilitate dental plaque removal is unclear. Here, we used a combination of biophysical analyses and microscopy to demonstrate that combined treatment with zinc and arginine targets the matrix of dental plaque biofilms, which destabilized the mechanical integrity of these microbial communities, making them more susceptible to removal by shear forces.

Antibacterial Efficacy against Streptococcus mutans of Different Desensitizing Dentifrices: A Comparison In vitro Study.

AIM: To evaluate the antibacterial efficacy of desensitizing dentifrices. MATERIAL AND METHODS: An experimental, in vitro, longitudinal, analytical, and prospective study was carried out. Subsequently, the following groups were formed: Streptococcus mutans vs Vitis® Sensible. S. mutans vs Sensodyne® Repair and Protect. Also, S. mutans vs Colgate® Sensitive Pro-ReliefTM and S. mutans vs Colgate Total 12® at 100, 50, 25, and 12.5%. Each Petri dish was properly labeled with the letter corresponding to the toothpaste and was placed in the incubator for 24 hours at 37°C. A 0.12% chlorhexidine solution was used as a positive control and distilled water as a negative control. The manuscript was written following the checklist for reporting in vitro studies (CRIS) guidelines. RESULTS: It was found that when comparing the inhibition halos of the desensitizing toothpaste against S. mutans, Colgate® Sensitive Pro-ReliefTM 100% paste had the highest efficacy at 24 and 48 hours with an average of 25.2 ± 1.0 and 23.5 ± 1.1 mm, respectively. On the other way, Sensodyne paste had no efficacy at any of its concentrations 100, 50, 25, and 12.5%. Finally, it was found that there were statistically significant differences between each of the groups evaluated with a p < 0.001. CONCLUSIONS: It was concluded that mainly the 100% pure concentrations of the desensitizing pastes had antibacterial efficacy against S. mutans. However, Sensodyne® Repair and Protect paste had no effect. CLINICAL SIGNIFICANCE: This research has clinical relevance because the use of desensitizing pastes is highly frequent. Therefore, it is necessary to know if these pastes offer an efficient antibacterial effect to control the main microorganisms of the oral cavity.

Application of non-inferiority testing in microhardness and its relationship to erosion: Relevance for hard tissue safety evaluations.

PURPOSE: To use non-inferiority statistical testing with simple microhardness measurements (SMH) as a prediction of potential erosive hard tissue damage of topical treatments on enamel. METHODS: Three independent experiments of a simple acid cycling demineralization (ACD) model were used to screen softening effects of various commercial beverages on dental enamel. The cycling model consists of six repeated exposures of enamel slabs with alternating treatments of artificial saliva over the course of 6 hours. After six repeated cycles, effects on surface microhardness were measured. Softening effects of beverages were evaluated using a statistical non-inferiority test of the positive control (water) and negative control (1% citric acid). To confirm whether softening effects as evaluated by a non-inferiority test translated to like differences in enamel erosion susceptibility, selected beverages then underwent more complex erosion cycling model (ECM) evaluation where enamel blocks were cycled with beverages (vs. historically established citric acid) and pooled saliva over a period of 5 days. The ECM also incorporated dentifrice treatments, sodium fluoride (NaF, Crest Cavity Protection, negative control) and a positive control stannous fluoride dentifrice (SnF2, Crest Pro-Health Advanced), to confirm model performance against historically published results of in situ erosion protection benefits of SnF2. RESULTS: There was a spectrum of softening properties of 16 commercial beverages in the ACD test, ranging from a ΔSMH of -22.6 to -316 vs. baseline. Four beverages were evaluated further in ECM testing. Despite a measurable change in SMH, Sprite and beer treatments in the ACD passed the statistical non-inferiority test and both were evaluated in erosion cycling, showing no enamel surface loss. Vinegar (~5% acetic acid) and Gatorade also showed measurable changes in SMH in the ACD, but they failed statistical non-inferiority testing. Both beverages subsequently showed significant enamel tissue loss (erosion) in further erosion cycling testing. This combined set of data suggests that simple surface microhardness evaluation may be used as a proxy for potential erosion surface loss if properly quantified. SnF2 dentifrice significantly reduced erosion from all erosive beverages with greater efficacy than NaF control dentifrice, consistent with prior clinical and in vitro evidence. CLINICAL SIGNIFICANCE: The ACD model with application of non-inferiority statistical testing is proposed as a simple model of hard tissue safety assessment of treatments, including oral hygiene products. Products that pass the non-inferiority test in ACD (surface softening) are proposed as safe for enamel as there is no suggestion from this data that teeth are at risk of tissue loss due to these products. On the other hand, products failing the non-inferiority test require confirmatory safety qualification in erosion cycling. Products equal or worse than citric acid with ACD or with significant erosion in ECM are suggested to warrant reformulation unless favorable safety data for enamel (lack of erosion) or the appropriate justification are provided.

Can brushing with regular and whitening dentifrices influence changes in color and micromorphologic surfaces of ceramic brackets subjected to coffee staining?

The aim of the present study was to evaluate the influence of brushing with regular or whitening dentifrices on the change in color and micromorphologic surface of ceramic orthodontic brackets subjected to coffee staining. Fifty ceramic brackets were subjected to cycles of coffee staining followed by brushing according to the following groups (n = 10): C, control (no brushing); DW, brushing with distilled water; CT, brushing with Colgate Total 12 Clean Mint (regular toothpaste); COW, brushing with Colgate Optic White (containing 1% hydrogen peroxide); and CUWA, brushing with Close-Up White Attraction (containing blue covarine). The color of the brackets was assessed using the Commission Internationale de l'Eclairage (CIE) L*a*b* system at 5 different timepoints: prior to staining (baseline) and after 1, 7, 14, and 21 days of staining and brushing cycles. The surface micromorphology of the brackets was assessed at the baseline timepoint and after 21 days. Kruskal-Wallis, Dunn, Friedman, and Nemenyi tests were applied (α = 0.05) for the statistical analysis. The C group demonstrated a significant reduction in L* and a significant increase in a* and b* values over time. For the DW group, the L* value was reduced but was higher than in the C group, and there were also significant increases in a* and b* from baseline values. A significant increase in the a* and b* values was observed in all groups (P < 0.05). Total color change (∆E*) increased over the period of evaluation for all whitening groups, although only the CT group presented significantly lower ∆E* than the other dentifrices. At the end of the test period, only the COW group exhibited a surface with higher porosity. None of the dentifrices prevented the brackets from staining, but they did reduce the magnitude of color change caused by coffee. The most significant difference was found in the CT group. Micromorphologic surface changes were observed when COW was employed.

Effect of high-fluoride dentifrice on root dentine and bacterial composition in a multispecies biofilm model.

The present study evaluated the effect of high-fluoride dentifrice on dentine demineralization and bacterial composition in a multispecies biofilm model in vitro. A seven-organism bacterial consortium was grown on bovine dentine discs in a high-throughput active attachment model. The biofilms were submitted twice per day to the following dentifrices treatments: 5,000 ppm F, 1,100 ppm F, with placebo as a negative control. After 5 days of biofilm growth, dentine samples were assessed by transversal microradiography, the biofilm was collected for bacterial counts and the pH of the media was determined. Lower integrated mineral loss values were observed when 5,000 ppm F-treatment was used compared to the other treatments. Overall microbiological counts decreased with increasing F-concentration as well the pH of the media throughout the experiment. The 5,000 ppm F-treatment caused a shift in microbial composition and reduced dentine demineralization in the in-vitro experimental model.

Effects of the association of high fluoride- and calcium-containing caries-preventive agents with regular or high fluoride toothpaste on enamel: an in vitro study.

OBJECTIVES: The aim of this in vitro study was to compare the caries-preventive effect of various high fluoride- and calcium-containing caries-preventive agents (> 22.000 ppm F- [ppm]) in adjunct to use of regular (1450 ppm) or high (5000 ppm) fluoride toothpaste on sound as well as demineralized enamel. MATERIALS AND METHODS: Bovine enamel specimens (n = 276; 5 mm × 3.5 mm × 3 mm) having one sound surface [ST] and one artificial caries lesion [DT] were randomly allocated to 12 groups. Interventions before pH-cycling were no intervention ([SC1/SC5]), application of varnishes/solutions containing NaF (22,600 ppm; Duraphat [NaF1/NaF5]); NaF + tricalcium phosphate (22,600 ppm; Clinpro White Varnish [TCP1/TCP5]); NaF + CPP-ACP (22,600 ppm; MI Varnish [CPP1/CPP5]); silver diammine fluoride (35,400 ppm; Cariestop 30%[SDF1/SDF5]); and NaF + calcium fluoride (45,200 ppm; Biophat[CaF1/CaF5]). During pH-cycling (28 days, 6 × 120 min demineralization/day) half of the specimens in each group were brushed (10 s; 2 × /day) with either 1,450 (NaF; named, e.g., TCP1) or 5,000 ppm (NaF; e.g., TCP5) dentifrice slurry. Differences in integrated mineral loss (∆∆Z) and lesion depth (∆LD) were calculated between values after initial demineralization and after pH-cycling using transversal microradiography. RESULTS: After pH-cycling, SC1/SC5 showed significantly increased ∆ZDT/LDDT values, indicating further demineralization (p < 0.05; paired t-test). Decreased ∆ZDT values, indicating non-significant remineralization, could only be observed in CaF1/CaF5 (p > 0.05; paired t-test). Additional use of all varnishes/solutions significantly decreased ∆∆ZDT/∆∆ZST and ∆LDDT/∆LDST compared to SC1/SC5 (p < 0.05;ANCOVA). Between 1450 and 5000 ppm dentifrices, a significant difference in ∆∆ZDT/∆∆ZST and ∆LDDT/∆LDST could only be observed for SC1/SC5 (p < 0.05; ANCOVA). CONCLUSION: Under the conditions chosen, all fluoride varnishes/solutions significantly reduced demineralization. Furthermore, a significant dose-response characteristic for fluoride varnishes could be revealed. However, no additional benefit could be observed, when varnishes were combined with high fluoride instead of regular fluoride dentifrices. CLINICAL RELEVANCE: For children and adolescents with high caries risks varnishes containing more than 22,600 ppm should be further investigated, as they offered higher caries-preventive effects in vitro. Furthermore, there seems to be no difference in the demineralization-inhibitory capacity of fluoride varnishes when used in combination with either standard or highly fluoridated dentifrices.

Effects of desensitizing dentifrices on dentin tubule occlusion and resistance to erosive challenges.

BACKGROUND: Many studies have demonstrated efficacy of casein phosphopeptide (CPP) containing products for dentin tubule occlusion for treatment of dentin sensitivity, but their effectiveness under dynamic erosive challenges remains to be elucidated. The purpose of the present study was to investigate the effectiveness of a desensitizing dentifrice containing CPP in occluding dentin tubules and resisting erosive challenges in comparison to that containing polyvinyl methyl ether/maleic acid (PVM/MA) copolymers. METHODS: A total of 33 dentin discs were prepared from coronal sections of human third molars and divided into 3 groups: a toothpaste containing CPP; a toothpaste containing PVM/MA and submicron silica; and a regular toothpaste (Controls). A soft-bristle toothbrush was used to brush the dentin discs with the dentifrices for 45 strokes in 30 s at a force of approximately 200 g. The brushing cycle was repeated after immersion of the dentin discs in artificial saliva overnight. The dentin discs were then challenged in orange juice for 10 min in an incubator rocking at 120 rpm. Three fields were randomly selected on each dentin disk surface to assess dentin tubule occlusions after each brushing cycle and after orange juice challenge with a 3D laser scanning microscope. Specimen cross sections were examined with a scanning electron microscope equipped with energy dispersive spectroscopy (SEM/EDS). RESULTS: After the first and second cycles of brushing, dentin tubules were occluded on average by 56.3% and 85.7% in CPP group, 66.2% and 88.1% in PVM/MA group, and 0.0 and 13.0% in the controls, respectively. There were no statistically significant differences in dentin tubule occlusions between the CPP and PVM/MA groups after two cycles of brushing (p>0.05). After dynamic erosive challenges with orange juice, 20.3% of the dentin tubules in the CPP group, 79.1% in the PVM/MA group and none in the control remained occluded (P<0.05). SEM/EDS imaging showed that dentin tubules were blocked with plugs containing dentifrice substances in CPP and PVM/MA groups after treatments, but none in the controls. CONCLUSIONS: Desensitizing dentifrices containing CPP or PVM/MA could effectively occlude dentin tubules after two cycles of brushing. PVM/MA in combination with submicron silicon dioxide exhibited stronger resistance to dynamic erosive challenges by acidic beverages. Inorganic fillers that can enter dentin tubules and resist erosive challenges may be key for desensitizing dentifrices.

Effect of tooth bleaching and application of different dentifrices on enamel properties under normal and hyposalivation conditions: an in situ study.

OBJECTIVE: The purpose of this in situ study was to evaluate different dentifrices on enamel after bleaching under normal and hyposalivatory conditions. MATERIALS AND METHODS: Twenty-four participants were assigned of which 12 had normal and 12 had low salivary flow. The study was conducted in 6 in situ experimental phases of 24 h duration: placebo, NaF, SnF2, F/Sn/Chitosan, F/Arginine, and F/Bioactive Glass. The specimens were previously bleached in vitro. Microhardness (SMH), roughness (Ra), and color analyses (CIELAB and ΔE00) were performed at baseline (T1), after bleaching (T2) and after in situ phase (T3). Scanning electron microscopy (SEM) and the elemental levels (wt%) of Ca, P, and Na and the proportion between Ca and P were determined using an energy-dispersive X-ray spectrometer (EDS) in T3. The SMH and Ra were analyzed by mixed models for repeated measures and Tukey Kramer. The color and Na% were analyzed by split-plot ANOVA and Tukey test. The EDS were analyzed by Mann's Whitney nonparametric, Friedman, and Nemenyi tests (p<0.05). RESULTS: The dentifrices placebo and NaF in the low flow presented lower SMH and higher Ra in T3 and lower Ca% compared to the same dentifrices in normal flow. For normal flow, SnF2 resulted in greater SMH. For low flow, SnF2, F/Sn/Chitosan, and F/Bioactive Glass resulted in higher SMH in T3 and did not differ from T1. F/Bioactive Glass showed lower Ra among the dentifrices evaluated for both salivary flows, whereas SnF2 showed the highest. F/Bioactive Glass showed a statistically significant difference from placebo for Ca%, P%, Na%. For ΔE*ab and ΔE00 (T1×T3), no differences were found for the dentifrices and salivary flows. CONCLUSION: The low salivary flow had less capacity for remineralization of bleached enamel compared to normal flow. Overall, the dentifrice with bioactive glass had the best performance in bleached enamel under low and normal salivary flow condition. CLINICAL RELEVANCE: It is recommended to use a bioactive glass-based dentifrice after bleaching to promote tooth enamel recovery for patients with or without impaired salivary flow.

Evaluation of Antimicrobial Effect of Air-Polishing Treatments and Their Influence on Human Dental Pulp Stem Cells Seeded on Titanium Disks.

Dental implants are one of the most frequently used treatment options for tooth replacement, and titanium is the metal of choice due to its demonstrated superiority in resisting corrosion, lack of allergic reactions and mechanical strength. Surface roughness of titanium implants favors the osseointegration process; nevertheless, its topography may provide a suitable substrate for bacterial biofilm deposition, causing peri-implantitis and leading to implant failure. Subgingival prophylaxis treatments with cleansing powders aimed to remove the bacterial accumulation are under investigation. Two different air-polishing powders-glycine and tagatose-were assayed for their cleaning and antimicrobial potential against a Pseudomonas biofilm and for their effects on human dental pulp stem cells (hDPSCs), seeded on sandblasted titanium disks. Immunofluorescence analyses were carried out to evaluate cell adhesion, proliferation, stemness and osteogenic differentiation. The results demonstrate that both the powders have a great in vitro cleaning potential in the early period and do not show any negative effects during hDPSCs osteogenic differentiation process, suggesting their suitability for enhancing the biocompatibility of titanium implants. Our data suggest that the evaluated cleansing systems reduce microbial contamination and allow us to propose tagatose as an adequate alternative to the gold standard glycine for the air-polishing prophylaxis treatment.

Effect of daily use of fluoridated dentifrice and bleaching gels containing calcium, fluoride, or trimetaphosphate on enamel hardness: an in vitro study.

OBJECTIVE: This study evaluated the effects of calcium gluconate (CaGlu), sodium fluoride (NaF), sodium trimetaphosphate (TMP), and NaF/TMP added to a 35% hydrogen peroxide (HP) bleaching gel for the reduction in enamel demineralization in vitro, with and without the use of a fluoridated dentifrice. DESIGN: Enamel blocks (n = 100) were obtained from bovine incisors (n = 200) after flattening and subjected to initial surface hardness (SH) analysis. The blocks were divided according to the bleaching gel (35% HP; 35% HP + 0.05% NaF; 35% HP + 0.25% TMP; 35% HP + 0.05% NaF + 0.25% TMP; 35% HP + 2% CaGlu) and were treated with ether non-fluoridated or fluoridated (1100 ppm) dentifrice. The bleaching gels were applied thrice (40 min/session) at the intervals of 7 days between each application. After 21 days, the final SH for the calculation of the percentage of SH loss (%SH) and cross-sectional hardness for the evaluation of the integrated hardness area (IH) were determined. RESULTS: Bleaching containing HP + NaF + TMP presented lowest %SH (p < 0.001), regardless of the dentifrice used. HP + NaF + TMP bleaching gel led to lower subsurface enamel mineral loss (IH) compared to the other groups (p < 0.001), and these did not differ from each other (p > 0.05). Daily use of fluoride dentifrice led to higher IH values (p < 0.001), regardless of the bleaching gels. CONCLUSION: The addition of NaF/TMP to a 35% HP bleaching gel remarkably reduced the mineral loss compared to the cases of the other bleaching gels, regardless of dentifrice. CLINICAL RELEVANCE: The association of TMP/NaF can be used as a strategy for reducing mineral loss during the bleaching procedure, even without the daily use of fluoride dentifrice.

Dentifrices or gels containing MMP inhibitors prevent dentine loss: in situ studies.

OBJECTIVES: Evaluate the effect of dentifrices or gels containing MMP inhibitors on dentine loss in situ. MATERIALS AND METHODS: Acrylic palatal appliances containing bovine dentine blocks were divided into two rows, corresponding to the groups erosion (ERO) and erosion associated with abrasion (ERO+ABR). For ERO, the appliances were immersed in a cola drink for 5 min, 4 times/day, while for ERO+ABR, the blocks were brushed for 15 sec with a dentifrice slurry after the second and third erosive challenges. Ten volunteers took part in study 1 (S1), where the dentifrices evaluated contained 1100 ppm fluoride as NaF, 0.61% green tea extract, or 0.012% chlorhexidine digluconate. Thirteen volunteers participated in study 2 (S2), in which the treatment was performed only once (1 min) with gels containing 400 µM EGCG (EGCG400), 0.012% chlorhexidine, 1 mM FeSO4, 1.23% F (NaF), placebo, or received no treatment. Dentine loss was analyzed by profilometry (µm). RESULTS: Regarding S1, ERO+ABR induced significantly higher dentine loss compared with ERO and all dentifrices tested led to significantly lower dentine loss when compared with placebo. For S2, regardless of the conditions or times of evaluation, gels containing EGCG, CHX, or FeSO4 led to significantly less wear compared with the other groups. CONCLUSION: Both dentifrices and gels containing MMP inhibitors significantly reduced dentine loss. CLINICAL RELEVANCE: Dentifrices and gels containing MMP inhibitors are able to increase the protection against dentine wear, although gels have a better effect when compared with fluoride gel, lasting up to 10 days after a single application.

Bioactive glass versus Arginine dentifrices on the reduction of dentin permeability and acid tolerance.

OBJECTIVES: To compare the efficacy of calcium sodium phosphosilicate (CSPS) and arginine dentifrices on dentin permeability and acid tolerance. MATERIAL AND METHODS: Sixty dentin discs were randomly assigned into 3 groups, then brushed for 1 min with CSPS, arginine, or fluoride (control) dentifrices. To test acid tolerance, each disc was soaked in 6% citric acid for 1 min. Dentin permeability was measured before, following brushing, and acid challenge. Ten discs per group were similarly treated and evaluated for tubule occlusion following a single dentifrice application, while other five discs per group were employed in an acid tolerance assay. RESULTS: The percentage reduction in dentin permeability was 39.26%, 32.27%, and 21.71% in the arginine, CSPS, and control groups, respectively. The differences in dentin permeability reduction between the arginine and CSPS groups following brushing and acid challenge were not significant (p = 0.398 and p = 0.211, respectively). The arginine dentifrice demonstrated a significant reduction in permeability compared with the control (p = 0.011). In addition, the occlusion exhibited by the arginine and CSPS dentifrices was more resistant to acid challenge compared with that of the control (p < 0.001). From SEM analysis, dentinal tubule occlusion was observed after a single application in all groups. Some open dentinal tubules were detected in the test groups, while almost all of the orifices were open in the fluoride group following acid challenge. CONCLUSIONS: There is no significant difference between arginine and CSPS dentifrices in reducing dentin permeability following a single application and acid challenge. Following acid challenge, the reduced permeability generated by arginine and CSPS was more stable compared with the fluoride dentifrice.

Dose-Response Effect of Fluoride Dentifrices on De-/Remineralization of Root Dentine in situ.

The present study aimed to evaluate the effect of fluoride (F) dentifrice with different F concentrations on root dentine de-/remineralization. Ten healthy volunteers took part in this randomized, double-blinded, cross-over, and split-mouth in situ experimental study. During 4 phases of 7 days, they wore a palatal appliance containing 4 bovine dentine blocks (2 sound and 2 with caries) of 4 × 4 × 2 mm. Treatments were performed with silica-based dentifrices containing 0, 700, 1,300, and 5,000 µg F/g (F as NaF). To provide a cariogenic challenge, a 20% sucrose solution was dripped 3 and 8 times daily on the carious-like and sound blocks, respectively. After each experimental phase, the percentage of surface hardness loss (%SHL) or recovery (%SHR) was calculated and the fluoride concentration in the biofilm was determined. The statistical analysis was performed using ANOVA and the Tukey post hoc test with p at 5%. The relationship between variables was analyzed by linear regression. The results showed a lower %SHL when 5,000 µg F/g dentifrice was used but without a statistically significant difference from the conventional one (1,300 µg F/g). Regarding remineralization and F in biofilms, the high-fluoride dentifrice was expressively superior in mineral replacement on the surface and in the F concentration in the biofilms, respectively, compared to the other 3 products (p < 0.05). Also, a significant linear fit between mineral loss/gain, F in biofilms, and fluoride concentration in the dentifrices could be observed. In conclusion, a dose-response F effect was observed, and the high-fluoride dentifrice was effective in enhancing root dentine remineralization in this short-term in situ study.