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This five-phase, single-blind, crossover in situ trial evaluated the effects of desensitizing or anti-erosive toothpastes on dentin erosive wear and tubule occlusion. Some characteristics such as relative dentin abrasivity (RDA), viscosity (V), cytotoxicity, and fluoride and calcium (Ca) availability of the toothpastes were also tested. Samples were positioned on removable intraoral appliances from 15 volunteers (n=4), according to the groups, C-control (0 ppm fluoride), F-sodium monofluorophosphate (MFP), A-MFP and arginine+calcium carbonate, CSP-calcium sodium phosphosilicate, and CS-MFP and calcium silicate+sodium phosphate. Erosion-abrasion cycling was performed (1% citric acid, 2min, 6×/day; toothbrushing, 5s, 2×/day). Surface loss (SL) was evaluated by optical profilometry. Environmental scanning electron microscopy images (ESEM) counted the number of open dentin tubules (ODTs). Data were statistically analyzed (α=0.05). There were no significant differences in SL among groups (p=0.468). The ODT for CSP, CS, and A groups were significantly lower than the control. CSP and CS presented significantly less ODT than F, but they did not significantly differ from A. F and CS were more abrasive than all the other toothpastes; CSP was more abrasive than A, and C was the least abrasive. CSP presented higher V (p

Objective To evaluate the effect of Er,Cr:YSGG laser associated or not with acidulated phosphate fluoride (APF) on the control of enamel erosion progression. Design: Enamel slabs (4 mm × 4 mm × 2 mm) from bovine incisors were flattened, polished, and received a tape on their test surfaces, leaving a 4 mm × 1 mm area exposed. Specimens were eroded (10 min in 1% citric acid solution) and randomly assigned into 8 experimental groups (n = 10): Control (no treatment); F (APF gel, 1.23% F, pH 3.6–3.9); Er,Cr:YSGG laser irradiation (P1: 0.25 W, 20 Hz, 2.8 J/cm2, 56 W/cm2); Er,Cr:YSGG laser irradiation (P2: 0.50 W, 20 Hz, 5.7 J/cm2, 1136 W/cm2); Er,Cr:YSGG laser irradiation (P3: 0.75 W, 20 Hz, 8.5 J/cm2, 1704 W/cm2); F + Laser P1; F + Laser P2; F + Laser P3. Specimens were then subjected to erosive cycling (5 min immersion in 0.3% citric acid solution, followed by immersion in artificial saliva for 60 min; 4×/day for 5 days). At the end of cycling, surface loss (SL, in μm) was determined with optical profilometry. Selected specimens were further evaluated by environmental scanning electron microscopy (n = 3). Data were analyzed using Kruskal-Wallis and Tukey tests (α = 0.05). Results: Group F + Laser P2 had the lowest SL value, differing significantly from the control; however, with no significant difference from the other groups. All groups, except F + Laser P2, showed no significant difference in SL when compared with the control. An irregular and rough surface, suggestive of a melting action of laser, was observed on enamel in Laser P2 and F + Laser P2 groups. Conclusions: Association of the Er,Cr:YSGG laser in parameter 2 with fluoride was the only treatment capable of controlling the progression of enamel erosion.

Objective To evaluate the effect of charcoal-based dentifrices on the color change (CC) and surface wear (SW) of resin composites. Materials and methods Five dentifrices, including three toothpastes: Colgate total-12 (C12), Black is the new White (CPX), and Natural (NAT); and two powders: Carvvo (CVV) and Whitemax (WMX), were evaluated. Composite blocks (5x5x2mm- Z350 3 M/ESPE, shade A2) were subjected to 417 and 5004 brushing cycles. The CC (n = 7, CIEDE2000; ΔE00 ) was evaluated using a spectrophotometer. SW (n = 5) was assessed using profilometry. The dentifrice particles were characterized by scanning electron microscopy (SEM). Results In 417 brushing cycles, resin composite exhibited higher color change upon being exposed to NAT, CVV and WMC than to C12 (p ≤ 0.05). In 5004 brushing cycles, resin composite showed higher color change values when exposed to all dentifrices, except C12 (p ≤ 0.05). The powders promoted higher SW on resin composite than C12 in both evaluation times (p ≤ 0.05). In 417 cycles, WMX caused higher SW on composite than C12, CPX, and NAT (p ≤ 0.05). No significant different SW was found between powders and charcoal-based toothpastes after 5004 brushing cycles (p > 0.05). SEM showed larger particles for powder than for toothpaste dentifrices. Conclusion Within the limitations of this study, both null hypotheses have been rejected. Resin composites exposed to charcoal-based dentifrices exhibited significantly (p ≤ 0.05) higher color change and surface wear than conventional toothpastes. Clinical significance Color change and surface wear shown by charcoal dentifrices may compromise the longevity of restorations.

Objective To evaluate dentin permeability and tubule occlusion of in-office desensitizing treatments, and to analyze their resistance to erosive/abrasive challenges. Design Ninety-one 1mm-thick dentin discs were immersed in EDTA solution for 5 min. After analyzing the maximum dentin permeability, the specimens were randomly allocated into 7 experimental groups (n = 10): Control (no treatment); Er,Cr:YSGG laser; Nd:YAG laser; Gluma Desensitizer; Duraphat; Pro-Argin toothpaste; Calcium Sodium Phosphosilicate (CSP) paste. The post-treatment permeability was assessed and then the specimens were subjected to a 5-day erosion-abrasion cycling protocol: 4x/day of immersion in citric acid solution (5 min;0.3%), followed by exposure to clarified human saliva (60 min). After the first and last acid challenges, specimens were brushed for 15 s, with exposure to the toothpaste slurry for total time of 2 min. Dentin permeability was re-measured (post-cycling). Percentage of dentin permeability for each experimental time was calculated in relation to the maximum permeability (%Lp). Data were analyzed with 2-way repeated measures ANOVA and Tukey tests (α = 0.05). Surface modifications were analyzed by scanning electron microscopy. Results In both experimental time CSP paste and Gluma Desensitizer did not differ from each other (p = 0.0874), and were the only groups that presented significantly lower %Lp than the Control (p = 0.026 and p = 0.022, respectively). After treatment, they were able to reduce dentin permeability in 82% and 72%, respectively. The %Lp post-cycling was higher than post-treatment value for all groups (p = 0.008). Dentin permeability increased 21% for CSP paste and 12% for Gluma, but they remained significant different from Control. Deposits on the surface were observed for CSP paste; and for Gluma, tubule diameters were shown to be smaller. Conclusions CSP paste and Gluma Desensitizer were the only treatments able to decrease dentin permeability post-treatment and to sustain low permeability post-cycling.

To evaluate the effect of desensitizing dentifrices on dentin wear and tubule occlusion using a three-phase, single blind, crossover in situ trial.The dentifrices containing Arginine and calcium carbonate (1,450 ppmF) and Novamin, (~1,426 ppmF) were tested in two conditions: A: abrasion and B: erosion/abrasion. A dentifrice without desensitizing agents was used as control (1,450 ppmF). In each study phase, 10 volunteers used intra-oral appliances containing dentin specimens (pre-treated with EDTA, to simulate hypersensitive dentin), which were either submitted to erosion with a cola-like drink (pH 2.6), 4×/day (2 minutes), followed by toothbrushing, using electric toothbrushes, with standard pressure (2×/ day, 5 seconds), or toothbrushing only. Dentin surface loss (SL, in µm) was determined with optical profilometry at the 3rd and 5th days of cycling. Dentin surface was analyzed with environmental scanning electron microscopy (ESEM), post EDTA and post cycling, and the dentin tubules were counted using Image J software. Data were statistically analyzed (α= 0.05).For condition A and B, there were no significant differences in SL among toothpastes in both experimental times. There were also no significant differences between times within groups. For ESEM, in A, Toothpaste with Novamin was the only dentifrice that showed significantly less opened tubules post cycling than post EDTA. In B, Toothpaste with Novamin and control toothpaste presented less opened tubules post cycling. In conclusion, toothbrushing with the tested dentifrices promoted similar levels of dentin loss; however, for tubule occlusion, the toothpaste with Novamin was the only toothpaste effective for both conditions, abrasion and erosion/abrasion.Ideally, desensitizing dentifrices should promote obliteration of the dentin tubules or nerve desensitization, without further contributing to the progression of dentin wear.

To evaluate the effect of desensitizing dentifrices on dentin erosive wear, using a 5-day erosion-abrasion-remineralization cycling model. The effect of the dentifrices on dentin's tubule occlusion was also investigated.30 samples of root dentin were randomly divided into three groups (n = 10): (1) Colgate Total 12 Clean Mint (control, 1,450 ppm F); (2) Colgate Sensitive Pro-Relief (1,450 ppm F, Pro-Argin); and (3) Sensodyne RepairProtect (1,450 ppm F, Novamin). Erosion was performed with a cola drink, for 5 minutes, 4x/day. Toothbrushing with the slurry dentifrices (1:2) was performed 2x/day, with electric toothbrushes, using standard pressure for 15 seconds. Surface loss (SL) was determined with optical profilometry at baseline and after the first, third and fifth days of cycling. Before treatment and in the end of the cycling, the amount of opened dentin tubules per area was evaluated in three randomly selected specimens from each group, by environmental scanning electron microscopy. The relative dentin abrasitivity (RDA) of the dentifrices was also measured. Data were statistically analyzed (α = 0.05).All the dentifrices showed a progressive increase in SL over time. However, no significant differences in SL among the dentifrices were observed at any time studied. Sensodyne RepairProtect significantly reduced the number of opened dentin tubules when compared to the other groups. Colgate Total 12 Clean Mint showed the highest RDA, followed by Sensodyne RepairProtect and then by Colgate Sensitive Pro-Relief. The desensitizing dentifrices tested produced a similar rate of erosive dentin wear to the conventional dentifrice; however, only Sensodyne RepairProtect was able to promote tubule occlusion.