Effectiveness of fluoride-containing toothpastes associated with different technologies to remineralize enamel after pH cycling: an in vitro study.

BACKGROUND: To evaluate the efficacy of fluoride-containing toothpastes with different technologies to remineralize artificial caries lesions in enamel. METHODS: Bovine enamel blocks were divided into three thirds: intact (untreated), demineralized (artificial caries lesion), and treated (caries lesion, pH cycling with dentifrices). Enamel blocks were randomly distributed into five groups (n = 12): Fluoride-free toothpaste, Colgate Oral Care (NC); Arginine-containing toothpaste, Colgate Total Daily Repair (PC); Silicate-based fluoride toothpaste: REFIX technology, regenerador + sensitive (RDC), NR-5 technology, Regenerate Enamel Science (RES), and NOVAMIN technology, Sensodyne Repair and Protect (SRP). The specimens were submitted to a pH cycling model for 6 days. The efficacy of the toothpastes was estimated by calculating the surface microhardness recovery (%SMHR) and the fluorescence recovery (ΔFRE) with quantitative light-induced fluorescence. The cross-sectional micromorphology of the enamel surface was also assessed using scanning electron microscopy. Elemental analyses (weight%) were determined with an energy-dispersive X-ray spectrometer (EDS). The results were compared to that of the control (NC). Data were statistically analyzed (5%). RESULTS: %SMHR could be ranked as follows: RDC = PC = RES = SRP > NC. Significantly higher %SMHR and ΔFRE means were observed after enamel treatment with RDC (22.7 and 46.9, respectively). PC (%SMHR = 18.8) was as efficacious as RDC to recover the surface microhardness with a significantly lower mean of ΔFRE (19.5). Only RDC was able to promote the formation of a mineralized layer on the surface of enamel enriched with silicon on the surface. CONCLUSIONS: The silicate-based fluoride toothpaste containing REFIX technology demonstrated greater efficacy in the remineralizing artificial caries than the other products.

Influence of energy drinks on enamel erosion: In vitro study using different assessment techniques.

BACKGROUND: Dental erosion has become a relevant public health problem in recent years and is related to the increase in the consumption of acidic beverages. Objective: The aim of the present study was to evaluate the erosive potential of energy drinks on dental enamel using an in vitro erosion model. MATERIAL AND METHODS: Thirty-eight blocks of human enamel were divided into four groups: G1- TNT Energy Drink®(n=8), G2- Red Bull® (n=10), G3- Monster Energy® (n=10), and G4- Coca-Cola® (n=10) (positive control). For the chemical analysis, the pH values, titratable acidity, and buffering capacity of the beverages were measured in triplicate. For the erosive test, the specimens were immersed in the beverages (5ml/block) for 30 minutes at room temperature with gentle shaking. Initial and final surface microhardness values were measured and the percentage of the loss of surface microhardness was calculated. Profilometry (surface loss and lesion depth) and mineral loss analysis (quantitative light-induced fluorescence) were performed. The data were analysed statistically using ANOVA followed by the Bonferroni correction, Pearson's correlation test, and multiple linear regression (p<0.05). RESULTS: The energy drinks had pH values ranging from 2.36 to 3.41. The lowest titratable acidity value was recorded for Monster Energy® and the highest was recorded for TNT Energy Drink®. All energy drinks had buffering capacity values higher than Coca-Cola®. Analysing the eroded enamel surface, the specimens submitted to TNT Energy Drink® had the greatest percentage loss of surface microhardness, surface loss, depth, and mineral loss, followed by those submitted to Red Bull® and Monster Energy®. Surface loss was the only predictor of mineral loss (p<0.001). CONCLUSIONS: Based on the study model employed, all the energy drinks examined were erosive to tooth enamel and TNT Energy Drink® had the worst behaviour. Key words:Energy drinks, tooth erosion, tooth demineralisation, hardness tests, quantitative light-induced fluorescence.

Nanoencapsulated fluoride as a remineralization option for dental erosion: an in vitro study.

OBJECTIVE: To compare the in vitro performance of different dentifrices indicated for dental erosion and a new dentifrice with controlled fluoride release system (NanoF) in terms of surface microhardness remineralization in enamel erosion lesions. MATERIALS AND METHODS: 72 human enamel specimens were divided into 6 groups (n = 12): PC (100% NaF - positive control); NC (Placebo - negative control); 50%nF (50% NanoF + 50% free NaF), 100%nF (100% NanoF); PN (Sensodyne® ProNamel™) and AG (Colgate® Sensitive Pro-Relief™). A surface microhardness analysis was performed before (SH0) and after (SH1) the erosion lesion formation. The blocks were submitted to a 5-day de-remineralization cycling model, consisting of 90 s immersion on 0.1% citric acid (4x/day) and 1 min treatment with dentifrice slurries along with 1 mL/block of human saliva (2x/day). Lastly, the final surface microhardness analysis (SH2) was measured and the percentage of surface microhardness remineralization (%SMHR) was calculated. Data were analysed with 2-way ANOVA and Tukey's test (p < .05). RESULTS: Statistically significant differences were observed for SH2 and %SMHR between NC and AG with the other groups (p < .05). The best %SMHR from the experimental groups was found in 100%nF and PN. CONCLUSION: Dentifrices with NanoF exhibited a surface microhardness remineralization similar to sodium fluoride (PC). Therefore, NanoF dentifrice can be an alternative to prevent and treat patients with dental erosion.