In vitro effect of fluoride gels supplemented with nano-sized sodium trimetaphosphate on enamel erosive wear.

OBJECTIVE: To assess the protective effect of fluoride (F) gels supplemented with micrometric or nano-sized sodium trimetaphosphate (TMPmicro and TMPnano, respectively) against enamel erosion in vitro. METHODS: Bovine enamel blocks (n = 140) were selected according to their surface hardness, and randomly divided into seven groups (n = 20/group), according to the gels tested: Placebo (without F/TMP), 4,500 µg F/g (4500F), 9,000 µg F/g (9000F), 4500F plus 2.5 % TMPnano (2.5 % Nano), 4500F plus 5 % TMPnano (5 % Nano), 4500F plus 5 % TMPnano (Micro 5 %) and 12,300 µg F/g (Acid gel). Blocks were treated once during one minute with the gels, and submitted to erosive (ERO, n = 10/group) or erosive plus abrasive (ERO+ABR, n = 10/group) challenges 4 times/day, for 90 s for each challenge (under reciprocating agitation), during consecutive 5 days. Blocks were analyzed by profilometry, and by surface (SH) and cross-sectional hardness (∆KHN). Data were submitted to two-way ANOVA, and Fisher's LSD test (p < 0.05). RESULTS: For ERO, both TMPnano-containing gels promoted enamel wear significantly lower than Placebo and 4500F, reaching levels similar to both positive controls (9000F and acid gel); significantly lower softening was observed for enamel treated with 4500F+5 % Micro and 4500F+2.5 % Nano. Also, the lowest ∆KHN values were observed for 4500F+2.5 % TMPnano among the TMP-containing gels. For ERO+ABR, the lowest enamel wear was achieved by the use of 4500F+5 % Nano among all gels, including both positive controls; lower softening was observed for Placebo and 9000F groups. CONCLUSION: The addition of 5 % nano-sized TMP to a low-fluoride gel produced superior protective effects for enamel under both challenges conditions, when compared with micrometric TMP, reaching values similar to or superior than both positive controls, respectively for ERO and ERO+ABR. CLINICAL SIGNIFICANCE: The supplementation of low-F gels with TMP was shown to significantly improve their effects on enamel erosive wear, and the use of nano-sized TMP further enhances this protective action.

Effect of fluoride gels with nano-sized sodium trimetaphosphate on the in vitro remineralization of caries lesions

Abstract Objective To evaluate the effects of fluoride (F) gels supplemented with micrometric or nano-sized sodium trimetaphosphate (TMPmicro and TMPnano, respectively) on the in vitro remineralization of caries-like lesions. Methodology Bovine enamel subsurface lesions (n=168) were selected according to their surface hardness (SH) and randomly divided into seven groups (n=24/group): Placebo (without F/TMP), 4,500 ppm F (4500F), 4500F + 2.5% TMPnano (2.5% Nano), 4500F + 5% TMPnano (5% Nano), 4500F + 5% TMPmicro (5% Micro), 9,000 ppm F (9000F), and 12,300 ppm F (Acid gel). The gels were applied in a thin layer for one minute. Half of the blocks were subjected to pH cycling for six days, whereas the remaining specimens were used for loosely- (calcium fluoride; CaF2) and firmly-bound (fluorapatite; FA) fluoride analysis. The percentage of surface hardness recovery (%SHR), area of subsurface lesion (ΔKHN), CaF2, FA, calcium (Ca), and phosphorus (P) on/in enamel were determined. Data (log10-transformed) were subjected to ANOVA and the Student-Newman-Keuls' test (p<0.05). Results We observed a dose-response relation between F concentrations in the gels without TMP for %SHR and ΔKHN. The 2.5% Nano and 5% Micro reached similar %SHR when compared with 9000F and Acid gels. For ΔKHN, Placebo and 5% Nano gels had the highest values, and 5% Micro, 2.5% Nano, 9000F, and Acid gels, the lowest. All groups had similar retained CaF2 values, except for Placebo and Acid gel. We verified observed an increase in Ca concentrations in nano-sized TMP groups. Regarding P, TMP groups showed similar formation and retention to 9000F and Acid. Conclusion Adding 2.5% nano-sized or 5% micrometric TMP to low-fluoride gels lead to enhanced in vitro remineralization of artificial caries lesions.

Efeito de géis fluoretados suplementados com nanopartículas de trimetafosfato de sódio sobre a remineralização de lesões de cárie e sobre o desgaste dental erosivo in vitro / Effect of fluoride gels supplemented with nano-sized Sodium Trimetaphosphate on the remineralization of caries lesions and erosive dental wear in vitro

O presente estudo avaliou o efeito de géis fluoretados suplementados com Trimetafosfato de Sódio (TMP) sobre a remineralização de lesões de cárie artificial e sobre o desgaste erosivo do esmalte dental bovino in vitro. Para o 1º capítulo, blocos de esmalte (n=168) com lesões de cárie artificiais foram analisados por dureza de superfície (DS) e aleatoriamente divididos em 7 grupos (n=24/grupo), de acordo com os géis testados: Placebo (sem F/TMP), 4500 µg F/g (4500F), 9000 µg F/g (9000F), 4500F+2,5% TMP nanoparticulado (2,5% Nano), 4500F+5% TMP nanoparticulado (Nano 5%), 4500F+5% TMP microparticulado (Micro 5%) e 12300 µg F/g (Acidulado). Os blocos foram tratados uma única vez com os géis (1 minuto) previamente à ciclagem de pH (6 dias). Em seguida, foram determinadas a porcentagem de recuperação de DS (%RDS), a área integrada da lesão de subsuperfície (ΔKHN) e o conteúdo de flúor fortemente-ligado (F), CaF2, cálcio (Ca) e fósforo (Pi) formado (após a aplicação dos géis) e retido no esmalte (após a ciclagem de pH). Os dados foram submetidos a ANOVA e teste de Student-Newman-Keuls (p<0,05). Os grupos 2,5% Nano e 5% Micro alcançaram %RDS semelhante aos géis 9000F e Acidulado. Para ΔKHN, os maiores valores foram observados para os grupos Placebo e 5% Nano, e os menores, para 2,5% Nano, 5% Micro, 9000F e Acidulado. Todos os grupos tiveram valores semelhantes de CaF2 retido, exceto Placebo e Acidulado. Um aumento nas concentrações de Ca foi observado para os grupos com TMP nanoparticulado. Em relação ao Pi formado e retido, os grupos com TMP foram semelhantes ao 9000F e ao Acidulado. No 2º capítulo, blocos de esmalte (n=140) foram aleatoriamente distribuídos em 7 grupos, utilizando os mesmos géis e modo de aplicação descritos no 1º capítulo. Metade da superfície dos blocos foi protegida com esmalte ácido-resistente (área controle), expondo a outra metade ao tratamento com os géis e ao desafio erosivo (ERO) ou erosivo+abrasivo (ERO+ABR). Após a aplicação dos géis, todos os blocos (n=20/grupo) foram submetidos a ERO (imersão em ácido cítrico 0,05 M, pH 3,2, 90 segundos, 4 vezes/dia, 5 dias, sob agitação), enquanto metade dos blocos (n=10/grupo) foi adicionalmente submetida a escovação (15 segundos) após cada desafio erosivo (ERO+ABR). Os blocos foram analisados por perfilometria e dureza em secção longitudinal (perda da dureza em profundidade - ∆KHN). Os dados foram submetidos a ANOVA e teste de Fisher (p<0,05). Para ERO, o desgaste do esmalte associado a 2,5% Nano, 5% Nano e Acidulado foi significantemente menor que 4500F, enquanto que para ERO+ABR o menor desgaste de esmalte foi observado para 5% Nano. Entre os géis com TMP, os menores valores de ∆KHN foram observados para 2,5% Nano para ERO. Os resultados permitem concluir que a adição de TMP nanoparticulado a 2,5% ou TMP microparticulado a 5% ao gel 4500F aumentou significativamente a remineralização de lesões artificiais de cárie in vitro. Quanto ao efeito sobre o desgaste dental erosivo, a adição de 5% de TMP nanoparticula do ao gel 4500F produziu efeitos protetores superiores quando comparado ao TMP microparticulado(AU)

The present study evaluated the effect of fluoride gels supplemented with sodium trimetaphosphate (TMP) on the remineralization of caries-like lesions and on erosive wear of bovine enamel in vitro. For the first chapter, enamel blocks (n=168) with caries-like lesions were evaluated by surface hardness (SH), and randomly divided into 7 groups (n=24/group), according to the tested gels: (a) Placebo (no F/TMP), 4,500 µg F/g (4500F), 9,000 µg F/g (9000F), 4,500F+2.5% nano-sized TMP (2.5% Nano), 4,500F+5% nano-sized TMP (5% Nano), 4,500F+5% micrometric TMP (5% Micro) and 12,300 µg F/g (Acid gel). Gels were applied on the blocks only once (1 minute) with the gels prior to the pH-cycling regimen (6 days). Following, the percentage of SH recovery (%SHR), integrated subsurface hardness area (ΔKHN), and firmly-bound fluoride (F), CaF2, calcium (Ca) and phosphorus (Pi) formed (after gels application) and retained (after pH cycling) in/on enamel were determined. Data were submitted to ANOVA and Student-Newman-Keuls test (p<0.05). The 2.5% Nano and 5% Micro groups reached %SHR similar to the 9000F and acid gel. For ΔKHN, the highest values were observed for the Placebo and Nano 5% groups, and the lowest, for 2.5% Nano, Micro 5%, 9000F and Acid gel. All groups had similar values of CaF2 retained on enamel, except Placebo and Acid gel. An increase in Ca concentrations was observed for the groups treated with nano-sized TMP. Regarding Pi formed and retained, groups treated with TMP were similar to 9000F and Acid gels. In the second chapter, the enamel blocks (n=140) were randomly divided in 7 groups, using the same gels and mode of application described in the first chapter. Half of the blocks' surface was protected with acidresistant varnish (control area), exposing the other half to the treatment with gels and to erosive (ERO) or erosive+abrasive (ERO+ABR) challenges. After treatment with the gels, all blocks (n=20/group) were submitted to ERO (immersion in 0.05 M citric acid, pH 3.2, 90 seconds, 4 times/day, 5 days, under agitation), while half of the blocks (n=10/group) was additionally subjected to brushing (15 seconds) after each erosive challenge (ERO+ABR). The blocks were evaluated by profilometry and cross-sectional hardness (integrated hardness loss in depth - ΔKHN). Data were submitted to ANOVA and Fisher's test (p<0.05). For ERO, enamel wear associated with 2.5% Nano, 5% Nano and Acid gels was significantly lower than 4500F, whereas for ERO+ABR the lowest enamel wear was observed at 5% Nano. Among the TMP gels, the lowest ΔKHN values were observed at 2.5% Nano under ERO conditions. The results allow to conclude that the addition of 2.5% nano-sized TMP or 5% micrometric TMP to the 4500F gel significantly increased the remineralization of artificial caries lesions in vitro. As for the effect on erosive tooth wear, the addition of 5% nanosized TMP to the 4500F gel produced superior protective effects when compared to micrometric TMP(AU)

Fluoride and calcium concentrations in the biofilm fluid after use of fluoridated dentifrices supplemented with polyphosphate salts.

OBJECTIVES: The present study evaluated fluoride (F) and calcium (Ca) concentrations in the biofilm fluid formed in situ under cariogenic challenge after using F dentifrices supplemented or not with sodium trimetaphosphate (TMP) or calcium glycerophosphate (CaGP). METHODS: Volunteers (n = 12) were randomly divided into 5 groups according to the toothpastes used: placebo (without F, CaGP or TMP), 1100 ppm F (1100F) and low-fluoride dentifrice (LFD, 550 ppm F) with no supplementation (550F) or supplemented with 1 % TMP (550F-TMP) or 0.25 % CaGP (550F-CaGP). In each phase, volunteers wore palatal appliances containing 4 bovine enamel blocks. Cariogenic challenge was performed with 30 % sucrose solution, 6 times/day. On the morning of the eigth day, biofilm samples were collected 12 h and 1 h after brushing and cariogenic challenge. F and Ca analyses in the biofilm fluid were performed with the inverted electrode after buffering with TISAB III and using the Arsenazo III method, respectively. Data were submitted to two-way ANOVA (repeated measures) and Student-Newman-Keuls test (p < 0.05). RESULTS: A dose-response relationship was verified between F concentrations in the dentifrices and in the biofilm fluid. Significant differences were observed among placebo, 550F, and 1100F only 1 h after brushing, without statistical differences among 550F, 550F-TMP, and 550F-CaGP. No defined trend was observed among the groups regarding Ca concentrations, with the highest values seen for placebo and 550F-CaGP. CONCLUSION: The anticaries effect of LFDs supplemented with CaGP or TMP cannot be related to an increased availability of F and Ca in the biofilm fluid. CLINICAL SIGNIFICANCE: The better performance of LFDs containing CaGP or TMP shown in previous studies should be attributed to their ability to interact with tooth enamel and with the biofilm, rather to their effect on the biofilm fluid.

Concentração de flúor e cálcio no fluido do biofilme associada ao uso de dentifrícios fluoretados suplementados com trimetafosfato de sódio ou glicerofosfato de cálcio, sob desafio cariogênico / Fluoride and calcium concentration in the biofilm fluid associated with fluoridated dentifrices supplemented with sodium trimetaphosphate or calcium glycerophosphate, under cariogenic challenge

Estudos recentes demonstraram que dentifrícios com concentração reduzida de fluoreto (DCRF, 550 μg F/g) suplementados com cálcio ou fosfato apresentam efetividade clínica semelhante à de um dentifrício convencional (DC, 1100 μg F/g). Entretanto, o mecanismo pelo qual estes compostos atuam nos processos de des- e remineralização ainda é incerto. O presente estudo avaliou a concentração de F e Ca no fluido do biofilme formado in situ sob desafio cariogênico após o uso de dentifrícios fluoretados, suplementados ou não com trimetafosfato de sódio (TMP) ou glicerofosfato de cálcio (CaGP). Voluntários (n=12) foram aleatoriamente divididos em 5 grupos, de acordo com os seguintes dentifrícios: Placebo (sem F, TMP ou CaGP), DC, DCRF sem suplementação (550F) e DCRF suplementado com 1% TMP (550F-TMP) ou 0,25% CaGP (550F-CaGP). Em cada fase, os voluntários utilizaram um dispositivo palatino contendo 4 blocos de esmalte bovino. O desafio cariogênico foi realizado com solução de sacarose 30%, 6 vezes ao dia. Na manhã do 8º dia, o biofilme foi coletado 1h e 12h após a escovação e desafio cariogênico. As análises de F e Ca foram realizadas com eletrodo invertido após tamponamento com TISAB III e por espectrofotometria (Arsenazo III), respectivamente. Os dados foram submetidos a ANOVA a 2 critérios (medidas repetidas) e teste de Student-Newman-Keuls (p<0,05). Uma relação dose-resposta entre as concentrações de F nos dentifrícios e no fluido do biofilme foi verificada...

Recent studies demonstrated that low fluoride dentifrices (LFD, 550 μg F/g) supplemented with calcium or phosphate have a similar effectiveness to a conventional dentifrice (CD, 1100 μg F/g). However, the mechanisms by which these compounds act on the de- and remineralization processes remain unclear. The present study evaluated fluoride (F) and calcium (Ca) concentrations in the biofilm fluid formed in situ under cariogenic challenge after using F dentifrices, supplemented or not with sodium trimetaphosphate (TMP) or calcium glycerophosphate (CaGP). Volunteers (n=12) were randomly divided into 5 groups according to the following toothpastes: Placebo (no F or CaGP, TMP), CD and LFD with no supplementation (550F) or supplemented with 1% TMP (550F-TMP) or 0.25% CaGP (550F-CaGP). In each phase, volunteers wore palatal appliances containing 4 bovine enamel blocks. The cariogenic challenge was produced using a 30% sucrose solution, 6 times a day. On the morning of the 8th day, biofilm samples were collected 1h and 12h after brushing and cariogenic challenge. F and Ca analyzes were performed with the inverted electrode after buffering with TISAB III and using the Arsenazo III method, respectively. Data were submitted to 2-way ANOVA (repeated measures) and Student-Newman-Keuls test (p<0.05). A dose-response relationship was verified between F concentrations in the dentifrices and those in the biofilm fluid. Significant differences were observed among Placebo, 550F and CD only 1 h after brushing, without statistical differences among 550F, 550F-TMP and 550F-CaGP. No defined trend was observed among the groups regarding Ca concentrations in the biofilm fluid, with the highest values found for Placebo and 500F-CaGP. It was concluded that the anticaries effects of LFDs supplemented with CaGP or TMP cannot be related to an increased availability of F and Ca in the biofilm fluid...