Iron supplementation reduces the erosive potential of a cola drink on enamel and dentin in situ

Iron has been suggested to reduce the erosive potential of cola drinks in vitro. Objective: The aim of this study was to evaluate in situ the effect of ferrous sulfate supplementation on the inhibition of the erosion caused by a cola drink. Material and Methods: Ten adult volunteers participated in a crossover protocol conducted in two phases of 5 days, separated by a washout period of 7 days. In each phase, they wore palatal devices containing two human enamel and two human dentin blocks. The volunteers immersed the devices for 5 min in 150 mL of cola drink (Coca-Cola (TM), pH 2.6), containing ferrous sulfate (10 mmol/L) or not (control), 4 times per day. The effect of ferrous sulfate on the inhibition of erosion was evaluated by profilometry (wear). Data were analyzed by paired t tests (p<0.05). Results: The mean wear (+/- se) was significantly reduced in the presence of ferrous sulfate, both for enamel (control: 5.8 +/- 1.0 mu m; ferrous sulfate: 2.8 +/- 0.6 mu m) and dentin (control: 4.8 +/- 0.8 mu m; ferrous sulfate: 1.7 +/- 0.7 mu m). Conclusions: The supplementation of cola drinks with ferrous sulfate can be a good alternative for the reduction of their erosive potential. Additional studies should be done to test if lower ferrous sulfate concentrations can also have a protective effect as well as the combination of ferrous sulfate with other ions.FAPESP [04/12632-2]FAPES

Impact of experimental Nano-HAP pastes on bovine enamel and dentin submitted to a pH cycling model

This in vitro study evaluated the preventive potential of experimental pastes containing 10% and 20% hydroxyapatite nanoparticles (Nano-HAP), with or without fluoride, on dental demineralization. Bovine enamel (n=15) and root dentin (n=15) specimens were divided into 9 groups according to their surface hardness: control (without treatment), 20 Nanop paste (20% HAP), 20 Nanop paste plus (20% HAP + 0.2% NaF), 10 Nanop paste (10% HAP), 10 Nanop paste plus (10% HAP + 0.2% NaF), placebo paste (without fluoride and HAP), fluoride paste (0.2% NaF), MI paste (CPP-ACP, casein phosphopeptide-amorphous calcium phosphate), and MI paste plus (CPP-ACP + 0.2% NaF). Both MI pastes were included as commercial control products containing calcium phosphate. The specimens were treated with the pastes twice a day (1 min), before and after demineralization. The specimens were subjected to a pH-cycling model (demineralization–6-8 h/ remineralization-16-18 h a day) for 7 days. The dental subsurface demineralization was analyzed using cross-sectional hardness (kgf/mm 2 , depth 10-220 µm). Data were tested using repeated-measures two-way ANOVA and Bonferroni's test (p<0.05). The only treatment able to reduce the loss of enamel and dentin subsurface hardness was fluoride paste (0.2% NaF), which differed significantly from the control at 30- and 50-µm depth (p<0.0001). The other treatments were not different from each other or compared with the control. The experimental Nanop pastes, regardless of the addition of fluoride, were unable to reduce dental demineralization in vitro

Cytotoxicity and effect on protease activity of copolymer extracts containing catechin

Peer reviewe

Effect of low fluoride acidic dentifrices on dental remineralization

This study evaluated the capacity of fluoride acidic dentifrices (pH 4.5) to promote enamel remineralization using a pH cycling model, comparing them with a standard dentifrice (1,100 µgF/g). Enamel blocks had their surface polished and surface hardness determined (SH). Next, they were submitted to subsurface enamel demineralization and to post-demineralization surface hardness analysis. The blocks were divided into 6 experimental groups (n=10): placebo (without F, pH 4.5, negative control), 275, 412, 550, 1,100 µgF/g and a standard dentifrice (positive control). The blocks were submitted to pH cycling for 6 days and treatment with dentifrice slurries twice a day. After pH cycling, surface and cross-sectional hardness were assessed to obtain the percentage of surface hardness recovery (%SHR) and the integrated loss of subsurface hardness (ΔKHN). The results showed that %SHR was similar among acidic dentifrices with 412, 550, 1,100 µgF/g and to the positive control (Tukey's test; p>0.05). For ΔKHN, the acidic dentifrice with 550 µg F/g showed a better performance when compared with the positive control. It can be concluded that acidic dentifrice 550 µgF/g had similar remineralization capacity to that of positive control.CNPq/PIBICCNPqPIBI

In situ remineralisation response of different artificial caries-like enamel lesions to home-care and professional fluoride treatments

Abstract\ud \ud Background\ud Artificial lesions produced by different protocols might directly influence the response to different remineralising treatments. This study compared the response of different artificial caries-like enamel lesions to home-care and professional fluoride based-remineralising treatments in situ.\ud \ud \ud Methods\ud The tested demineralising protocols were methylcellulose- MC gel, polyacrylic acid - PA gel, tetraethyl methylene diphosphanate - TEMDP solution, and acetate- Buffer solution. The lesions were remineralised using an in situ model, following a crossover and double blind design. Twelve subjects wore intra-oral appliances during 3 phases (3 d each): control (C) (saliva); home-care F− treatment (FD) (1,100 ppm F− dentifrice, 2x1 min/day); and professional (FVD) (22,600 ppm F− varnish) plus FD. The de-remineralisation was measured by transverse microradiography-TMR and hardness (surface hardness/cross-sectional hardness, SH/CSH, respectively).\ud \ud \ud Results\ud For SH, lesions produced by PA gel were the only one showing significant differences among the remineralising treatments (C x FD x FVD); while the TEMDP lesion were not responsive to any fluoride treatment (for both SH/CSH). For TMR, there were no differences among the remineralising treatments, regardless of the type of lesion. Generally, the most responsive lesions to fluoride were the less demineralised lesions (considering hardness: PA gel and Buffer).\ud \ud \ud Conclusions\ud The type of lesion has influence on the surface remineralisation degree induced by home-care and professional fluoride treatments using this in situ model.We would like to thank the subjects who took part of the in situ research\ud and FAPESP by the financial support (scholarship for the first author, Process number: 2011/03907-1)

Effect of chronic exercise on fluoride metabolism in fluorosis-susceptible mice exposed to high fluoride

Abstract The present study investigated the effect of chronic exercise on fluoride (F) metabolism in fluorosis-susceptible mice exposed to high-F and explored the relationship between F concentrations in bone and plasma. Thirty male mice were randomised into three groups: Group I (No-F, No-Exercise), Group II (50 ppmF, No-Exercise), Group III (50 ppmF, Exercise). Body weight and physical performance of all mice were measured at baseline and end of experiment. F concentrations of plasma and bone were measured at the end of experiment. Mean plasma F concentration was significantly higher (p < 0.001) in Groups II and III compared with Group I. Mean bone F concentration was also significantly higher (p < 0.01) in Groups II and III compared with Group I. There was a significant correlation (p = 0.01, r = 0.54) between F concentration of plasma and bone. Mean body weight of Group I mice was significantly higher than Group II (p < 0.001) and Group III (p = 0.001) mice at the end of the experiment. This study, which provides the first data on the effect of chronic exercise on F metabolism in fluorosis-susceptible mice, suggests no effect of chronic exercise on F in plasma and bone. However, exposure to high-F resulted in lower body weight and exercise capacity in mice

Current issues regarding health surveillance of fluoride concentrations in foods

This study analyzed the position of the Federal (Brazil), State (Sao Paulo), and municipal (Bauru, Sao Paulo) governments, civil society representatives, the regulated sector, and research associations concerning issues with fluoride content in foods. Analysis of the interviews (N = 15) used a qualitative methodology (collective subject discourse theory). Various central ideas were identified, including the need for stronger health surveillance in monitoring and controlling fluoride levels, educational measures, and more research in the area. The study concludes that the health surveillance approach to fluoride levels in foods is necessary, but still incipient. There is a mismatch between research output and surveillance. Regulation alone does not suffice to solve all the issues. Health risk communication and health education measures need to be implemented. Issues with fluoride on food labels need further research for the intervention to be effective

Calcium glycerophosphate supplemented to soft drinks reduces bovine enamel erosion

Objective: This in vitro study evaluated the effect of calcium glycerophosphate (CaGP) supplemented to soft drinks on bovine enamel erosion. Material and methods: Four pH-cycles were performed, alternating demineralization by the beverage and remineralization in artificial saliva. Results: Mean wear (+/- SD, mu m) was 7.91 +/- 1.13, 7.39 +/- 1.01, 7.50 +/- 0.91 and 5.21 +/- 1.08 for Coca-Cola (TM) without CaGP or containing CaGP at 0.1, 1.0 or 2.0 mM, respectively, while no wear was detected for CaGP at 5.0 and 10.0 mM. Corresponding figures for Sprite Zero (TM) without CaGP or containing CaGP at 0.1, 1.0, 2.0, 5.0 or 10.0 mM were 8.04 +/- 1.30, 7.84 +/- 0.71, 7.47 +/- 0.80, 4.96 +/- 0.81, 3.99 +/- 0.10 and 1.87 +/- 0.12, respectively. Conclusion: Supplementation of both beverages with CaGP seems to be an alternative to reduce their erosive potential.PIBIC-CNPq/USPPIBICCNPq/US

Effect of Physical Exercise and Genetic Background on Glucose Homeostasis and Liver/Muscle Proteomes in Mice.

We compared the parameters related to glucose homeostasis, and liver and muscle proteomes in fluorosis-susceptible (A/J; S) and fluorosis-resistant (129P3/J; R) mice in response to fluoride (F) exposure and exercise. Ninety male mice (45 R-mice and 45 S-mice) were randomized into three groups: (SI; RI) No-F, No-Exercise, (SII; RII) 50 ppm F, No-Exercise, (SIII; RIII) 50 ppm F, Exercise. Overall, mean F concentrations in the plasma and femur were significantly higher in R-mice compared with S-mice. In R-mice, exercise resulted in an increase in F accumulation in the femur. In S-mice, the mean plasma glucose level was significantly higher in Group II compared with Groups I and III. There was an increase in liver proteins involved in energy flux and antioxidant enzymes in non-exercise groups (I, II) of S-mice in comparison with the corresponding groups of R-mice. The results also showed a decrease in muscle protein expression in Group I S-mice compared with their R-mice counterparts. In conclusion, the findings suggest an increased state of oxidative stress in fluorosis-susceptible mice that might be exacerbated by the treatment with F. In addition, fluorosis-susceptible mice have plasma glucose levels higher than fluorosis-resistant mice on exposure to F, and this is not affected by exercise

Effect of in situ aspartame mouthwash to prevent intrinsic and extrinsic erosive tooth wear

The aim was to evaluate whether aspartame regular mouthwash prior to erosive challenges with citric or hydrochloric acids would be able to prevent erosive enamel wear. This randomized, single blind in situ study was conducted with 3 crossover phases of 5 days. Polished bovine enamel blocks (n=252) were randomly divided among 6 groups/ 3 phases/ 21 volunteers. The groups under study were: aspartame solution (0.024% of aspartame in deionized water - experimental group), deionized water (negative-control) and stannous-containing solution (Elmex® Erosion Protection Dental Rinse; positive-control); subjected to erosion on citric acid or hydrochloric acid. Four times per day the volunteers rinsed the intraoral appliance with the respective solutions (in situ) prior to immersion of half of the appliance in 0.05M citric acid and the other half in 0.01M hydrochloric acid for 120 seconds (extraoral). The response variable was enamel loss by profilometry. Data were analyzed by ANOVA and Tukey?s test (p<0.05). No difference on enamel loss was found between aspartame solution and deionized water. Stannous-solution resulted in less enamel loss compared to deionized water. Hydrochloric acid resulted in higher enamel loss than citric acid. In this model, aspartame was not able to prevent erosive tooth wear against citric or hydrochloric acids