ABSTRACT
ABSTRACT: The purpose of this research was to determine the cleaning and whitening ability of two charcoal containing toothpastes compared with baking soda, activated charcoal and a hydrogen peroxide containing whitening toothpaste. Tea-stained enamel/dentin slices were mounted dentin side down in cylinders of auto-polymerizing acrylic and subjected to simulated brushin g. Total color, ΔE, and stained area were measured using a reflectance spectrophotometer and ImageJ software using a Hue, Chroma, and Brightness color threshold method; respectively, at prescribed brushing intervals of baseline, months 1, 6 and 12. A two- w ay repeated measure analysis of variance was performed, with included factors being toothpaste group and time. Statistical analys is revealed the included factor of brushing time interval was significant (p<0.05) for both ΔE and stained area. There was significant interaction for both main effects (p<0.05) for the dependent variable of stained area alone. Significant reduction in ΔE values occurred in all groups except Optic White at the 1-month interval. Statistically significant reduction in stained area occurred at 1-mon th for the baking soda group only. Post-hoc Tukey HSD tests revealed there was significant group*time interaction for baking soda at month 1 for the variable stained area. The charcoal containing (Crest 3D with Charcoal and Colgate Essentials) and non-charcoal contai ning toothpastes (Optic White) only produced a significant stain removal at the 6-month interval.
RESUMEN: El propósito de esta investigación fue determinar la capacidad de limpieza y blanqueamiento de dos pastas dentales que contienen carbón en comparación con bicarbonato de sodio, carbón activado y una pasta dental blanqueadora que contiene peróxido de hidrógeno. Los cortes de esmalte/dentina teñidos con té se montaron con el lado de la dentina hacia abajo, en cilindros de acrílico autopolimerizable y se sometieron a un cepillado simulado. El color total, ΔE y el área teñida se midieron usando un espectrofotómetro de reflectancia y el software ImageJ usando un método de umbral de color de tono, croma y brillo; respectivamente, en los intervalos de cepillado prescritos al inicio, los meses 1, 6 y 12. Se realizó un análisis de varianza de medidas repetidas de dos vías, con factores incluidos como el grupo de pasta de dientes y el tiempo. El análisis estadístico reveló que el factor incluido del intervalo de tiempo de cepillado fue significativo (p<0,05) tanto para ΔE como para el área manchada. Hubo interacción significativa para ambos efectos principales (p<0,05) para la variable dependiente del área teñida sola. Se produjo una reducción significativa en los valores de ΔE en todos los grupos excepto Optic White en el intervalo de 1 mes. Se produjo una reducción estadísticamente significativa en el área manchada al mes solo para el grupo de bicarbonato de sodio. Las pruebas post-hoc Tukey HSD revelaron que hubo una interacción significativa entre grupo y tiempo para el bicarbonato de sodio en el mes 1 para el área manchada variable. Las pastas dentales que contenían carbón (Crest 3D con Charcoal y Colgate Essentials) y las pastas de dientes que no contenían carbón (Optic White) solo produjeron una eliminación significativa de las manchas en el intervalo de 6 meses.
ABSTRACT
?-Amylase is an endoamylase catalysing the degradation of starch into maltose, maltotriose and glucose. The enzyme isolated from microbial sources possess unique properties of thermostability thus making it a useful tool in the detergent industry. Here, we explored a strain of thermophilic bacteria Bacillus licheniformis for its potential application in detergent industry. The B. licheniformis RA31 was isolated from soil samples of hot spring in Rampur district of Himachal Pradesh, India and grown on optimized media to produce thermostable ?-amylase. The enzyme was ethanol precipitated, purified (12.93 fold, 55.52% yield and 621.93 U/mg specific activity) to homogeneity with a single band on SDS-PAGE (66 kDa) and native-PAGE (68 kDa). Purified enzyme displayed best activity in pH 8 buffer and ?80% activity was retained in pH 7 and 10. It showed temperature optima at 70°C. Its activity was decreased at 70°C (70% after 4 h), 80°C (65% after 4 h) and 90°C (50% after 1 h). The enzyme was stimulated (126%; 5 mM) by barium chloride. It was relatively stable in the presence of commercial detergents (109-125%), SDS (84%), Tween 20 (88%), EDTA (72%) and ?-ME (70% at 10 mM). Km and Vmax for the enzymatic hydrolysis of starch were 0.339 mg/mL and 1.450 mg/min, respectively. The enzyme revealed the highest specificity towards wheat starch granule (140% after 1 h) and SEM analysis displayed its biodegradation (2-10 h). Improved cleaning efficiency of potato curry stained fine cotton clothes were observed with enzyme assisted detergent advance treatment (0.02% w/v). The enzyme showed potential applications in detergent industry.