Distribution of fluoride and calcium in plaque biofilms after the use of conventional and low-fluoride dentifrices.

BACKGROUND: The distribution of fluoride and calcium in plaque after the use of fluoride dentifrices has not yet been determined. AIM: To evaluate fluoride and calcium distribution in sections of biofilms generated in situ after the use of conventional and low-fluoride dentifrices. DESIGN: Children (n = 11, 8­10 years old) brushed with placebo (fluoride-free), low-fluoride (513 mgF/kg), and conventional (1072 mgF/kg) dentifrices twice daily for 1 week, following a double-blind, cross-over protocol. Biofilms were generated using Leeds in situ devices, which were collected 1 and 12 h after brushing, and sectioned through their depth. Sections were grouped (10 x 5 µm) for fluoride and calcium analysis. Sections 4 lm thick were used for image analysis and determination of biomass fraction. Results were analysed by ANOVA, Tukey's test, and linear regression analysis (P < 0.05). RESULTS: Fluoride and calcium were mostly located at the outer sections of biofilms for all dentifrices tested, and these ions were directly correlated throughout most of biofilm's sections. Results for conventional dentifrice were significantly higher than for the placebo, but did not differ from those for the low-fluoride dentifrice. CONCLUSIONS: The use of a low-fluoride dentifrice did not promote a higher fluoride uptake in inner biofilms' sections, as hypothesized. As plaque fluoride was significantly elevated only after the use of the conventional dentifrice, the recommendation of low-fluoride formulations should be done with caution, considering both risks and benefits.

Supplementation of soft drinks with metallic ions reduces dissolution of bovine enamel.

OBJECTIVE: The aim of this study was to evaluate the effect of the addition of metallic ions to carbonated drinks on their erosive potential. MATERIAL AND METHODS: Powdered enamel was added to carbonated beverages (Coca-ColaTM or Sprite ZeroTM and shaken for 30 s. The samples were then immediately centrifuged and the supernatant removed. This procedure was repeated 5 times with the beverages containing Cu2+, Mg2+, Mn2+ or Zn2+ (1.25-60 mmol/L). For Coca-ColaTM, the concentration of each ion that exhibited the highest protection was also evaluated in combination with Fe2+. The phosphate or calcium released were analyzed spectrophotometrically. Data were analyzed using ANOVA and Tukey's test (p<0.05). RESULTS: For Coca-ColaTM, the best protective effect was observed for Zn2+ alone (10 mmol/L) or in combination (1 mmol/L) with other ions (12% and 27%, respectively, when compared with the control). Regarding Sprite ZeroTM, the best protective effect was observed for Cu2+ at 15 and 30 mmol/L, which decreased the dissolution by 22-23%. Zn2+ at 2.5 mmol/L also reduced the dissolution of powdered enamel by 8%. CONCLUSIONS: The results suggest that the combination of metallic ions can be an alternative to reduce the erosive potential of Coca-ColaTM. Regarding Sprite ZeroTM, the addition of Cu2+ seems to be the best alternative.

Supplementation of soft drinks with metallic ions reduces dissolution of bovine enamel

OBJECTIVE: The aim of this study was to evaluate the effect of the addition of metallic ions to carbonated drinks on their erosive potential. MATERIAL AND METHODS: Powdered enamel was added to carbonated beverages (Coca-ColaTM or Sprite ZeroTM and shaken for 30 s. The samples were then immediately centrifuged and the supernatant removed. This procedure was repeated 5 times with the beverages containing Cu2+, Mg2+, Mn2+ or Zn2+ (1.25-60 mmol/L). For Coca-ColaTM, the concentration of each ion that exhibited the highest protection was also evaluated in combination with Fe2+. The phosphate or calcium released were analyzed spectrophotometrically. Data were analyzed using ANOVA and Tukey's test (p<0.05). RESULTS: For Coca-ColaTM, the best protective effect was observed for Zn2+ alone (10 mmol/L) or in combination (1 mmol/L) with other ions (12% and 27%, respectively, when compared with the control). Regarding Sprite ZeroTM, the best protective effect was observed for Cu2+ at 15 and 30 mmol/L, which decreased the dissolution by 22-23%. Zn2+ at 2.5 mmol/L also reduced the dissolution of powdered enamel by 8%. CONCLUSIONS: The results suggest that the combination of metallic ions can be an alternative to reduce the erosive potential of Coca-ColaTM. Regarding Sprite ZeroTM, the addition of Cu2+ seems to be the best alternative. .

Factors influencing fluoride ingestion from dentifrice by children.

OBJECTIVE: This study assessed the percentage of the amount of dentifrice loaded onto the toothbrush that is ingested by children, taking into account age, the amount of dentifrice used during toothbrushing, and the dentifrice flavor. METHODS: The sample consisted of 155 children of both genders attending public kindergartens and schools in Bauru, Brazil, divided into 5 groups (n = 30-32) of children aged 2, 3, 4, 5 and 6 years old. The dentifrices used were Sorriso™ (1219 ppm F, peppermint-flavored) and Tandy™ (959 ppm F, tutti-frutti-flavored). The assessment of fluoride intake from dentifrices was carried out six times for each child, using 0.3, 0.6, and 1.2 g of each dentifrice, following a random, crossover distribution. Brushing was performed by the children or their parents/caregivers according to the home habits and under the observation of the examiner. Fluoride present in the expectorant and on toothbrush was analyzed with an ion-specific electrode after HMDS-facilitated diffusion. Fluoride ingestion was indirectly derived. Results were analyzed by 3-way repeated-measures anova and Tukey's tests (P < 0.05) using the percent dentifrice ingested as response variable. RESULTS: Age and percent dentifrice ingested for both dentifrices, and the three amounts used were inversely related (P < 0.0001). Percent dentifrice ingested was significantly higher after the use of Tandy™ under all conditions of the study when compared with Sorriso™ (P < 0.0001). Significant differences were observed when brushing with 0.3 g when compared with 1.2 g, for both dentifrices tested (P < 0.05). CONCLUSIONS: The results indicate that all variables tested must be considered in preventive measures aiming to reduce the amount of fluoride ingested by young children.

Efeito do íon ferro na prevenção da erosão dentária: estudos in vitro e in situ / Effect of iron on the prevention of tooth wear: in vitro and in situ studies

Este projeto teve como objetivos investigar o efeito do íon ferro (Fe+2), associado ou não ao íon flúor (F-), na redução da erosão do esmalte e da dentina bovinos, bem como desenvolver e avaliar um dentifrício enriquecido com Fe+2 para a prevenção da erosão associada à abrasão. Foram realizados 4 subprojetos: (1) Determinação do efeito protetor de concentrações crescentes do Fe+2 (0 a 120 mmol/L) associadas ou não ao F- (0 a 4 g/mL), contra a dissolução do pó de esmalte bovino in vitro; (2) Avaliação, in vitro, do efeito protetor do Fe+2 a 10 mmol/L contra a dissolução mineral da superfície do esmalte bovino; (3) Desenvolvimento e avaliação, in vitro, de dentifrícios fluoretados enriquecidos com diferentes concentrações de Fe+2, visando à prevenção da perda mineral do esmalte bovino; (4) Avaliação, in situ, do efeito inibidor do dentifrício acrescido de Fe+2 e F- na desmineralização do esmalte e dentina bovinos sadios ou previamente erodidos. As variáveis de resposta utilizadas foram a quantificação da perda de fósforo (colorimetria) e o desgaste (perfilometria, m) para os subprojetos 1 e 2, e 3 e 4, respectivamente. Os dados foram submetidos à análise estatística (p<0,05). Para o Subprojeto (1), a ANOVA a 2 critérios e o teste de Bonferroni revelaram que soluções contendo Fe+2 a 1,25, 2,5, 5,0, 10, 15 e 30 mmol/L reduziram significativamente a dissolução do pó de esmalte bovino em 18, 18, 23, 35, 35 e 55%, respectivamente, em comparação ao controle (sem Fe+2). Na presença de F-, o efeito do Fe+2 na inibição da dissolução do esmalte foi reduzido, não havendo efeito sinérgico entre estes íons nas condições testadas. No Subprojeto (2), a ANOVA a 2 critérios e o teste de Bonferroni, mostraram uma redução significativa na desmineralização da superfície do esmalte bovino em torno de 30 a 40%, quando se utilizou solução de Fe+2 a 10 mmol/L. No Subprojeto (3), a ANOVA revelou diferença significativa...

The aims of this study were to investigate the effect of iron (Fe+2) associated or not to fluoride (F-) on the reduction of bovine enamel and dentin erosion, as well as to develop and evaluate a dentifrice containing Fe+2 to prevent erosion associated to abrasion. Four subprojects were done: (1) In vitro determination of the protective effect of increasing Fe+2 concentrations (0 to 120 mmol/L) associated or not to F- (0 to 4 g/mL) against the dissolution of powdered enamel; (2) In vitro evaluation of the protective effect of 10 mol/L Fe+2 against the mineral dissolution of superficial bovine enamel; (3) Development and in vitro evaluation of fluorided dentifrices containing different Fe+2 concentrations in order to prevent the mineral loss of bovine enamel; and (4) In situ evaluation of the effect of a dentifrice containing Fe+2 and F- on the demineralization of sound or previously eroded bovine enamel and dentin. The response variables were quantification of phosphate loss (colorimetry) and tooth wear (perfilometry, m) for the subprojects 1 and 2, and 3 and 4, respectively. Data were submitted to statistical analyses (p <0.05). In subproject (1), two-way ANOVA and Bonferronis test revealed that solutions containing 1.25, 2.5, 5.0, 10.0, 15.0 and 30.0 mmol/L Fe+2 significantly reduced the dissolution of powdered enamel at 18, 18, 23, 35, 35 and 55%, respectively, in comparison to control (without Fe+2). In the presence of F-, the effect of Fe+2 on the dissolution of enamel was reduced and no synergistic effect between these ions was observed in the tested conditions. In Subproject (2), two-way ANOVA and Bonferronis test showed a significant reduction on surface demineralization of bovine enamel (around 30-40%), when the solution containing Fe+2 at 10 mmol/L was used. In Subproject (3), ANOVA revealed a significant difference among the groups (Placebo, 1,100 g/mL F, Crest®, 1.0 mg/g Fe+2, 2.5 mg/g Fe+2, 5.0 mg/g Fe+2, F- (1, 100 g/mL) + 1,0 mg/g...

Efeito do íon ferro na prevenção da erosão dentária: estudos in vitro e in situ / Effect of iron on the prevention of tooth wear: in vitro and in situ studies

Este projeto teve como objetivos investigar o efeito do íon ferro (Fe+2), associado ou não ao íon flúor (F-), na redução da erosão do esmalte e da dentina bovinos, bem como desenvolver e avaliar um dentifrício enriquecido com Fe+2 para a prevenção da erosão associada à abrasão. Foram realizados 4 subprojetos: (1) Determinação do efeito protetor de concentrações crescentes do Fe+2 (0 a 120 mmol/L) associadas ou não ao F- (0 a 4 g/mL), contra a dissolução do pó de esmalte bovino in vitro; (2) Avaliação, in vitro, do efeito protetor do Fe+2 a 10 mmol/L contra a dissolução mineral da superfície do esmalte bovino; (3) Desenvolvimento e avaliação, in vitro, de dentifrícios fluoretados enriquecidos com diferentes concentrações de Fe+2, visando à prevenção da perda mineral do esmalte bovino; (4) Avaliação, in situ, do efeito inibidor do dentifrício acrescido de Fe+2 e F- na desmineralização do esmalte e dentina bovinos sadios ou previamente erodidos. As variáveis de resposta utilizadas foram a quantificação da perda de fósforo (colorimetria) e o desgaste (perfilometria, m) para os subprojetos 1 e 2, e 3 e 4, respectivamente. Os dados foram submetidos à análise estatística (p<0,05). Para o Subprojeto (1), a ANOVA a 2 critérios e o teste de Bonferroni revelaram que soluções contendo Fe+2 a 1,25, 2,5, 5,0, 10, 15 e 30 mmol/L reduziram significativamente a dissolução do pó de esmalte bovino em 18, 18, 23, 35, 35 e 55%, respectivamente, em comparação ao controle (sem Fe+2). Na presença de F-, o efeito do Fe+2 na inibição da dissolução do esmalte foi reduzido, não havendo efeito sinérgico entre estes íons nas condições testadas. No Subprojeto (2), a ANOVA a 2 critérios e o teste de Bonferroni, mostraram uma redução significativa na desmineralização da superfície do esmalte bovino em torno de 30 a 40%, quando se utilizou solução de Fe+2 a 10 mmol/L. No Subprojeto (3), a ANOVA revelou diferença significativa...

The aims of this study were to investigate the effect of iron (Fe+2) associated or not to fluoride (F-) on the reduction of bovine enamel and dentin erosion, as well as to develop and evaluate a dentifrice containing Fe+2 to prevent erosion associated to abrasion. Four subprojects were done: (1) In vitro determination of the protective effect of increasing Fe+2 concentrations (0 to 120 mmol/L) associated or not to F- (0 to 4 g/mL) against the dissolution of powdered enamel; (2) In vitro evaluation of the protective effect of 10 mol/L Fe+2 against the mineral dissolution of superficial bovine enamel; (3) Development and in vitro evaluation of fluorided dentifrices containing different Fe+2 concentrations in order to prevent the mineral loss of bovine enamel; and (4) In situ evaluation of the effect of a dentifrice containing Fe+2 and F- on the demineralization of sound or previously eroded bovine enamel and dentin. The response variables were quantification of phosphate loss (colorimetry) and tooth wear (perfilometry, m) for the subprojects 1 and 2, and 3 and 4, respectively. Data were submitted to statistical analyses (p <0.05). In subproject (1), two-way ANOVA and Bonferronis test revealed that solutions containing 1.25, 2.5, 5.0, 10.0, 15.0 and 30.0 mmol/L Fe+2 significantly reduced the dissolution of powdered enamel at 18, 18, 23, 35, 35 and 55%, respectively, in comparison to control (without Fe+2). In the presence of F-, the effect of Fe+2 on the dissolution of enamel was reduced and no synergistic effect between these ions was observed in the tested conditions. In Subproject (2), two-way ANOVA and Bonferronis test showed a significant reduction on surface demineralization of bovine enamel (around 30-40%), when the solution containing Fe+2 at 10 mmol/L was used. In Subproject (3), ANOVA revealed a significant difference among the groups (Placebo, 1,100 g/mL F, Crest®, 1.0 mg/g Fe+2, 2.5 mg/g Fe+2, 5.0 mg/g Fe+2, F- (1, 100 g/mL) + 1,0 mg/g...

Effect of calcium pre-rinse and fluoride dentifrice on remineralisation of artificially demineralised enamel and on the composition of the dental biofilm formed in situ.

OBJECTIVE: This in situ blind crossover study investigated the effect of calcium (Ca) rinse prior to the use fluoride (F) dentifrice on remineralisation of artificially demineralised enamel and on the composition of biofilm. DESIGN: During four phases of 14 days, 10 volunteers wore appliances containing two artificially demineralised bovine enamel blocks. Three times a day, they rinsed with 10 mL of Ca (150 mM) or placebo rinse (1 min). A slurry (1:3, w/v) of F (1030 ppm) or placebo dentifrice was dripped onto the blocks. During 1 min, the volunteers brushed their teeth with the respective dentifrice. The appliance was replaced into the mouth and the volunteers rinsed with water. The biofilm formed on the blocks was analysed for F and Ca. Enamel alterations were evaluated by the percentage of surface microhardness change (%SMHC), cross-sectional microhardness (% mineral volume) and alkali-soluble F analysis. Data were analysed by ANOVA (p<0.05). RESULTS: The use of the Ca pre-rinse before the F dentifrice produced a six- and four-fold increase in biofilm F and Ca concentrations, respectively. For enamel, the remineralisation was significantly improved by the Ca pre-rinse when compared to the other treatments. There was a significantly higher concentration of alkali-soluble F in enamel when the F dentifrice was used, but the Ca pre-rinse did not have any significant additive effect. CONCLUSIONS: According to our protocol, the Ca pre-rinse significantly increased biofilm F concentration and, regardless the use of F dentifrice, significantly enhanced the remineralisation of artificially demineralised enamel.

Effect of iron supplementation on the erosive potential of carbonated or decarbonated beverage

This study evaluated, in vitro, the effect of iron (previously exposed with enamel powder or added directly to the beverage) on the erosive potential of carbonated or decarbonated beverage. Four sets of experiments were done. For groups E1 and E3, a solution containing 30 mmol/L FeSO4 was added to bovine enamel powder (particles between 75-106 mm) before exposure to the carbonated or decarbonated beverage (Sprite Zero®), respectively. For groups E2 and E4, 15 mmol/L FeSO4 was added directly to the carbonated or decarbonated beverage, respectively. Control groups were included for comparison. In controls C1 and C3, the experiments E1 and E3 were repeated, but the iron solution was replaced by deionized water. For controls C2 and C4, the carbonated and decarbonated beverage, respectively, was used, without addition of iron. After addition of the beverage to the powdered enamel (40 mg enamel powder/400 mL of final volume), the sample was vortexed for 30 s and immediately centrifuged for 30 s (11,000 rpm). The supernatant was removed after 1 min 40 s. This procedure was repeated in quintuplicate and the phosphate released was analyzed spectrophotometrically. The results were analyzed by Student's t-test (p<0.05). E2 presented the best results with a significant inhibition (around 36 percent) of phosphate released. For E3 and E4 a non-significant inhibition (around 4 and 12 percent, respectively), was observed. For E1 an increase in phosphate loss was detected. Thus, the protective effect of iron seems to be better when this ion is directly added to the carbonated beverage.

Effect of iron supplementation on the erosive potential of carbonated or decarbonated beverage.

This study evaluated, in vitro, the effect of iron (previously exposed with enamel powder or added directly to the beverage) on the erosive potential of carbonated or decarbonated beverage. Four sets of experiments were done. For groups E1 and E3, a solution containing 30 mmol/L FeSO4 was added to bovine enamel powder (particles between 75-106 mm) before exposure to the carbonated or decarbonated beverage (Sprite Zero(R)), respectively. For groups E2 and E4, 15 mmol/L FeSO4 was added directly to the carbonated or decarbonated beverage, respectively. Control groups were included for comparison. In controls C1 and C3, the experiments E1 and E3 were repeated, but the iron solution was replaced by deionized water. For controls C2 and C4, the carbonated and decarbonated beverage, respectively, was used, without addition of iron. After addition of the beverage to the powdered enamel (40 mg enamel powder/400 mL of final volume), the sample was vortexed for 30 s and immediately centrifuged for 30 s (11,000 rpm). The supernatant was removed after 1 min 40 s. This procedure was repeated in quintuplicate and the phosphate released was analyzed spectrophotometrically. The results were analyzed by Student's t-test (p<0.05). E2 presented the best results with a significant inhibition (around 36%) of phosphate released. For E3 and E4 a non-significant inhibition (around 4 and 12%, respectively), was observed. For E1 an increase in phosphate loss was detected. Thus, the protective effect of iron seems to be better when this ion is directly added to the carbonated beverage.

Effect of iron on bovine enamel and on the composition of the dental biofilm formed "in situ".

OBJECTIVES: This study investigated in situ the effect of iron (Fe) on the reduction of demineralization of bovine enamel, as well as on the composition of dental biofilm. DESIGN AND METHODS: Twelve volunteers were included in this blind crossover study, which was conducted in two stages of 14 days each. For each stage, the volunteers received palatal appliances containing four blocks of bovine enamel (4 mm x4 mm x 2.5 mm). Six volunteers dripped a solution of 15 mmol L(-1) ferrous sulphate onto the fragments and the remaining six dripped deionized water (eight times per day). After five minutes, a fresh 20% (w/v) sucrose solution was dripped onto all enamel blocks. During the experimental period the volunteers brushed their teeth with non-fluoridated dentifrice. After each stage, the percentage of surface microhardness change (%SMHC) and area of mineral loss (DeltaZ) were determined on enamel and the dental biofilm formed on the blocks was collected and analysed for F, P, Ca, Fe and alkali-soluble carbohydrates. The concentrations of F, Ca and Fe in enamel were also analysed after acid biopsies. RESULTS: There was a statistically significant increase in the P and Fe concentrations in the biofilms treated with ferrous sulphate (p<0.05), which was not observed for F, Ca and alkali-soluble carbohydrates. The group treated with ferrous sulphate had significantly lower %SMHC and DeltaZ when compared to control (p<0.05). CONCLUSIONS: These results showed that ferrous sulphate reduced the demineralization of enamel blocks and altered the ionic composition of the dental biofilm formed in situ.