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1.
BMC Oral Health ; 24(1): 680, 2024 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-38867181

RESUMEN

BACKGROUND: To investigate the effect of a 50% ascorbic acid with 50% citric acid solution on the immediate shear bond strength (SBS) of metallic brackets after tooth bleaching. The enamel etching pattern and the required quantity of these combined acids as antioxidants following 35% hydrogen peroxide (HP) bleaching were also determined. METHODS: The stability of the solution at room temperature was assessed at various time intervals. Fifty teeth were randomly divided into five groups: non-bleached (G1), bleached then acid etched (G2), bleached followed by a 10-minute treatment with 10% sodium ascorbate and acid etched (G3), 5-minute treatment with 50% ascorbic acid (G4), and 5-minute treatment with a combination of 50% ascorbic acid and 50% citric acid (G5). Groups G2, G3, G4 and G5 were bleached by 35% HP gel for a total of 32 min. Acid etching in groups G1, G2, and G3 was performed using 37% phosphoric acid (Ormco®, Orange, CA, USA) for 15 s. In all groups, metal brackets were immediately bonded using Transbond™ XT primer and Transbond™ PLUS adhesive, with light curing for 40 s. The SBS was tested with a universal testing machine, and statistical analysis was conducted using one-way ANOVA followed by Tukey's HSD test. The level of significance was set at p < 0.05 for all statistical tests. RESULTS: Stability tests demonstrated that the combined acids remained effective for up to 21 days. Group G5 significantly increased the SBS of bleached teeth to the level of G1 (p < 0.05), while G3 did not achieve the same increase in SBS (p > 0.05). SEM analysis revealed enamel etching patterns similar to those of both control groups (G1 and G2). Kinetic studies at 6 min indicated that the antioxidation in G5 reacted 0.2 mmole lower than in G3 and G4. CONCLUSION: 5-minute application of the combined acids enhanced the SBS of bleached teeth comparable to unbleached teeth. The combined acids remain stable over two weeks, presenting a time-efficient, single-step solution for antioxidant application and enamel etching in orthodontic bracket bonding.


Asunto(s)
Ácido Ascórbico , Ácido Cítrico , Recubrimiento Dental Adhesivo , Esmalte Dental , Soportes Ortodóncicos , Resistencia al Corte , Blanqueamiento de Dientes , Ácido Ascórbico/farmacología , Ácido Cítrico/farmacología , Ácido Cítrico/química , Blanqueamiento de Dientes/métodos , Humanos , Proyectos Piloto , Esmalte Dental/efectos de los fármacos , Recubrimiento Dental Adhesivo/métodos , Grabado Ácido Dental , Antioxidantes/farmacología , Propiedades de Superficie , Factores de Tiempo , Peróxido de Hidrógeno/química , Blanqueadores Dentales/química , Ácidos Fosfóricos , Análisis del Estrés Dental
2.
Dent J (Basel) ; 11(5)2023 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-37232761

RESUMEN

This study investigates how a new substance, composed of ethyl ascorbic acid and citric acid, affects the shear bond strength (SBS) of metal brackets when bonded to bleached teeth. Forty maxillary premolar teeth were used and randomly placed into four groups (n = 10): the control group did not undergo bleaching; the remaining groups underwent bleached using 35% hydrogen peroxide. In group A, 37% phosphoric acid was applied after bleaching. In group B, 10% sodium ascorbate was used for ten minutes before 37% phosphoric acid. In group C, 35%3-O-ethyl-l-ascorbic acid plus 50% citric acid solution (35EA/50CA) was applied for 5 min. The subgroups were bonded immediately after bleaching. The SBS was determined with a universal testing machine and analyzed using one-way ANOVA and then Tukey's HSD tests. Adhesive remnant index (ARI) scores were determined with a stereomicroscope and analyzed with a chi-squared test. The significance level was 0.05. Group C demonstrated significantly higher SBS values than group A (p < 0.001), but was not significantly different than the control group or group C (p > 0.05). The ARI scores were significantly different among the groups (p < 0.001). In conclusion, enamel surface treatment using 35EA/50CA improved the reduced SBS to an acceptable clinical level and reduced the clinical chair time.

3.
Anal Methods ; 14(43): 4344-4351, 2022 11 10.
Artículo en Inglés | MEDLINE | ID: mdl-36263601

RESUMEN

This study developed a novel voltage step electrocoagulation (VSEC) technique on paper for analysis and classification of red wine samples. The concept relies on the electrode system applying voltage steps along a strip of filter paper soaked with a wine sample. The system employed a cathode array system (CAS) for voltage step application and an aluminium anode undergoing corrosion to form the green sludges responsible for wine color bleaching along the paper. The VSEC technique led to the shade of colors along the paper which can be observed by the naked-eye or using image processing software. The system was applied to classify 15 wine samples into different groups and to perform dilution and adulteration tests. In addition, the approach could be applied to approximate antioxidant properties of the wine samples as observed via the correlation between the results from VSEC and IC50 values obtained from the DPPH assay with an R2 of 0.76.


Asunto(s)
Vino , Vino/análisis , Antioxidantes/análisis , Ácido Hipocloroso/análisis , Electrocoagulación
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