TiF4 and NaF varnishes as anti-erosive agents on enamel and dentin erosion progression in vitro

Objective This study assessed the effect of fluoride varnishes on the progression of tooth erosion in vitro. Material and Methods: Forty-eight enamel and 60 root dentin samples were previously demineralized (0.1% citric acid, pH 2.5, 30 min), leading to a baseline and erosive wear of 12.9 and 11.4 µm, respectively. The samples were randomly treated (6 h) with a 4% TiF4 varnish (2.45%F-, pH 1.0), a 5.42% NaF varnish (2.45%F-, pH 5.0), a placebo varnish and no varnish (control). The samples were then subjected to erosive pH cycles (4x90 s/day in 0.1% citric acid, intercalated with artificial saliva) for 5 days. The increment of the erosive tooth wear was calculated. In the case of dentin, this final measurement was done with and without the demineralized organic matrix (DOM). Enamel and dentin data were analyzed using ANOVA/Tukey’s and Kruskal-Wallis/Dunn tests, respectively (p<0.05). Results The TiF4 (mean±s.d: 1.5±1.1 µm) and NaF (2.1±1.7 µm) varnishes significantly reduced enamel wear progression compared to the placebo varnish (3.9±1.1 µm) and control (4.5±0.9 µm). The same differences were found for dentin in the presence and absence of the DOM, respectively: TiF4 (average: 0.97/1.87 µm), NaF (1.03/2.13 µm), placebo varnish (3.53/4.47 µm) and control (3.53/4.36 µm). Conclusion The TiF4 and NaF varnishes were equally effective in reducing the progression of tooth erosion in vitro. .

Análise físico-química do MTA e do cimento Portland associado a quatro diferentes radiopacificadores / Physicochemical analysis of MTA and Portland cement associated with four different radiopacifiers

Introdução: O Mineral Trióxido Agregado (MTA) é composto por cimento Portland (CP) e um radiopacificador (óxido de bismuto). Objetivo: Avaliar tempo de presa, solubilidade, pH, liberação de íons Cálcio e radiopacidade do cimento Portland puro ou associado a quatro radiopacificadores (sulfato de bário, carbonato de bismuto, óxido de bismuto e iodofórmio), comparados ao MTA branco (Angelus, Londrina, Brasil). Material e Método: A proporção empregada CP/radiopacificador foi de 4:1 em peso, (80% de cimento Portland e 20% de radiopacificador). A especificação 57 da ADA foi usada para avaliação do tempo de presa. A solubilidade foi analisada segundo a especificação ISO 6876/2001. A avaliação do pH foi realizada com peagâmetro digital e a liberação de íons Ca++foi verificada por meio de espectrofotômetro de absorção atômica. A radiopacidade foi determinada em milímetros de alumínio (mm/Al). Os resultados foram submetidos aos testes de Análise de Variância e Tukey, nível de significância 5%. Resultado: O sulfato de bário não alterou o tempo de presa final do CP. Radiopacidade inferior ao mínimo recomendado pelas normas da ADA nº 57 e ISO 6876/2001 foi observada para CP e CP associado com sulfato de bário. O CP associado ao iodofórmio apresentou solubilidade acima dos 3% recomendados pela ISO 6876/2001. Todos os materiais proporcionaram alcalinização do meio e promoveram liberação de íons cálcio. Conclusão: Carbonato de bismuto ou óxido de bismuto proporcionaram tempo de presa inicial, solubilidade, pH, liberação de íons Cálcio e radiopacidade adequados quando associados ao CP. .

Introduction: Mineral Trioxide Aggregate (MTA) is composed of Portland cement (PC), and a radiopacifier (bismuth oxide). Objective: To evaluate the setting time, solubility, pH, calcium ion release and radiopacity of pure Portland cement and its association to four radiopacifiers, (Barium sulfate, bismuth carbonate, bismuth oxide and iodoform), and White MTA (Angelus, Londrina, Brazil). Material and Method: The ratio CP/radiopacifier used was 4:1 by weight (80% Portland cement and 20% radiopacifier). The setting time was evaluated according the specification ADA 57. The solubility was analyzed according to ISO 6876/2001 specification. The pH was evaluated using a digital pHmeter and the release of Ca++ ions by atomic absorption spectrophotometer. The radiopacity was measured in millimeters of aluminum (mm/Al). The results were submitted to ANOVA and Tukey tests using 5% of significance level. Result: Barium sulfate did not alter the final setting time of the PC. Observed radiopacity was less than the minimum recommended by ADA 57 and ISO 6876/2001 for CP and CP associated with barium sulfate. The PC associated with iodoform showed solubility above the 3% recommended by ISO 6876/2001. All materials provided alkalinization and promoted calcium ion release. Conclusion: Bismuth carbonate and bismuth oxide provided proper initial setting time, solubility, pH, calcium ion release and radiopacity when combined with CP. .

Evaluation of fluoride release from experimental TiF4 and NaF varnishes in vitro

Fluoride varnishes play an important role in the prevention of dental caries, promoting the inhibition of demineralization and the increase of remineralization. Objective: This study aimed to analyze the amount of fluoride released into water and artificial saliva from experimental TiF4 and NaF varnishes, with different concentrations, for 12 h. Material and Methods: Fluoride varnishes were applied on acrylic blocks and then immersed in 10 ml of deionized water and artificial saliva in polystyrene bottles. The acrylic blocks were divided in seven groups (n=10): 1.55% TiF4 varnish (0.95% F, pH 1.0); 3.10% TiF4 varnish (1.90% F, pH 1.0); 3.10% and 4% TiF4 varnish (2.45% F, pH 1.0); 2.10% NaF varnish (0.95% F, pH 5.0); 4.20% NaF varnish (1.90% F, pH 5.0); 5.42% NaF varnish (2.45% F, pH 5.0) and control (no treatment, n=5). The fluoride release was analyzed after 1/2, 1, 3, 6, 9 and 12 h of exposure. The analysis was performed using an ion-specific electrode coupled to a potentiometer. Two-way ANOVA and Bonferroni's test were applied for the statistical analysis (p<0.05). Results: TiF4 varnishes released larger amounts of fluoride than NaF varnishes during the first 1/2 h, regardless of their concentration; 4% TiF4 varnish released more fluoride than NaF varnishes for the first 6 h. The peak of fluoride release occurred at 3 h. There was a better dose-response relationship among the varnishes exposed to water than to artificial saliva. Conclusions: The 3.10% and 4% TiF4 -based varnishes have greater ability to release fluoride into water and artificial saliva compared to NaF varnish; however, more studies must be conducted to elucidate the mechanism of action of TiF4 varnish on tooth surface. .

Seven years of external control of fluoride levels in the public water supply in Bauru, São Paulo, Brazil

Fluoridation of the public water supplies is recognized as among the top ten public health achievements of the twentieth century. However, the positive aspects of this measure depend on the maintenance of fluoride concentrations within adequate levels. Objective: To report the results of seven years of external control of the fluoride (F) concentrations in the public water supply in Bauru, SP, Brazil in an attempt to verify, on the basis of risk/benefit balance, whether the levels are appropriate. Material and Methods: From March 2004 to February 2011, 60 samples were collected every month from the 19 supply sectors of the city, totaling 4,641 samples. F concentrations in water samples were determined in duplicate, using an ion-specific electrode (Orion 9609) coupled to a potentiometer after buffering with TISAB II. After the analysis, the samples were classified according to the best risk-benefit adjustment. Results: Means (±standard deviation) of F concentrations ranged between 0.73±0.06 and 0.81±0.10 mg/L for the different sectors during the seven years. The individual values ranged between 0.03 and 2.63 mg/L. The percentages of the samples considered “low risk” for dental fluorosis development and of “maximum benefit” for dental caries prevention (0.55-0.84 mg F/L) in the first, second, third, fourth, fifth, sixth, and seventh years of the study were 82.0, 58.5, 37.4, 61.0, 89.9, 77.3, and 72.4%, respectively, and 69.0% for the entire period. Conclusions: Fluctuations of F levels were found in the public water supply in Bauru during the seven years of evaluation. These results suggest that external monitoring of water fluoridation by an independent assessor should be implemented in cities where there is adjusted fluoridation. This measure should be continued in order to verify that fluoride levels are suitable and, if not, to provide support for the appropriate adjustments.