Stain Removal Research Articles

Stain-removal potential of keratinase produced by Bacillus species isolated from feather waste

The aim of this study was to determine the potential of keratinases produced by Bacillus species isolated from poultry feather waste in stain removal. The effect of individual and combined detergent components on the keratinase activity of EZYKer-51, EZYKer-50 and EZYKer-53 enzymes produced from keratin degrading Bacillus licheniformis-K51, Bacillus subtilis-K50 and Bacillus sp.-K53 respectively was determined. EZYKer-51, which had the least enzyme inhibition in the presence of the detergent component was used as the enzyme component in detergent formulation and a wash performance analysis test was carried out to compare the stain removal capacity of DETKER 51 (detergent formulated using EZYKer-51 as enzyme component) with a commercial enzyme. Data were analyzed using descriptive statistics. EZYKer-51 showed a significantly higher (P≤0.05) enzyme activity in the presence of the detergent ingredients for both the crude and purified forms of the enzyme compared with the activities of EZYKer-50 and EZYKer-53, except for the activities (8.02±1.32 U/mL and 7.94±0.63 U/mL) in the presence of 15% LAS and 5% liquid paraffin. Visually, better stain removal was achieved when endogenous protease of commercial enzyme was replaced with EZYKer-51. These results suggest that keratinase EZYKer-51 may be a useful alternative for applications in detergent formulation.

Efficacy Of Indigenous Microbes for Removal of Oil Contaminated Soil by Producing Biosurfactant

Bacteria with ability to produce biosurfactants have potential applications in environmental protection. They are surface active chemicals that can lower the surface tension between two liquids or a solid and a liquid. Microorganisms of several types manufacture them. Objective: To isolate, optimize, screen, and describe bacteria that produce biosurfactants from petroleum-contaminated soil. Methods: Isolates were named as ZMS1 and ZMS2, which were gram positive rods with mucoidy colonies and off white or colorless appearance, respectively. The isolation was carried out using initial screening methods including blood hemolytic assay, foaming activity, emulsification assay and oil spreading technique in kerosene supplemented media at culture conditions of pH7 and temperature 37ºC. Results: The results of these different tests showed the production of biosurfactant by bacteria. Stain removal efficiency of bacterial supernatant considered as a biosurfactant, was also tested following previously described method. Both isolates, ZMS1 and ZMS2 were producing biosurfactants with the capacity remove stains of blood and tea. Furthermore, to get the biosurfactant production using cheaper carbon source, potato peel extract and molasses extract were used as a carbon source in synthetic medium for the growth of ZMS1 and ZMS2. Despite the fact that the isolates produced biosurfactant, they were not purified or eluted. However, both the isolates ZMS1 and ZMS2 shown their significance in several biotechnological and industrial domains. Conclusions: Present study will be helpful in future and these microbes can be utilized for the remediation of oil polluted soil, which in turn can be proven in the improvement of soil fertility.

The impact of stain removal and bleaching on the adhesion strength of water-based varnish layers in oak

The aim of this study is to determine the performance of water-based varnish adhesion on the process of stain removal, bleaching and impregnation applied to wood surfaces. In order to accomplish this objective, the selected sessile oak (Quercus petreae Mill.) wood samples were firstly contaminated with grease and PVAc glue, after they were cleaned. Then, the wood samples were bleached by using oxalic acid (C2H2O4) and hydrogen peroxide (H2O2). Secondly, preprocessed specimens impregnated with imersol aqua (IA) and wood protective chemicals (WP) and together both these chemicals (IA+WP). Finally, adhesion strength performance of the wood samples were tested after they covered by single component primary resin (SCPR), double component polyurethane modified with acrylic (DCAP) and double component elastic polyurethane (DCEP). The adhesion resistance of varnish layers is determined according to ASTM 4541 principles. As a result, the oil stain removal and the protective chemical applications decreased the adhesion strength on the wood surface of water-based varnish layers. Contrary, the glue stain removal and the C2H2O4 and H2O2 bleaching increased the adhesion strength. Also, it was determined that DCEP applications have the highest value in oak wood samples.

Evaluation of Charcoal and Sea Salt–Lemon-based Whitening Toothpastes on Color Change and Surface Roughness of Stained Teeth

To compare the efficacy of two naturally based commercially available whitening toothpastes charcoal and sea salt-lemon on stain removal of teeth in terms of color change and surface roughness. Twenty-seven intact bovine incisors were selected and randomly allocated into three main groups (n = 9) according to the tested toothpaste [I: Signal Complete 8 Charcoal; II: sea salt-lemon essence Closeup natural smile; and III: Signal Complete 8 Original (control)]. Following 4 successive days of staining protocol, each specimen in its corresponding group was brushed with the toothpaste using toothbrush simulator apparatus for three brushing cycles. Color assessment using Vita Easyshade spectrophotometer and surface roughness (Ra) measurement using contact type profilometer were performed for each specimen at baseline, after staining, and after each tooth brushing cycle. Nonparametric color data and parametric surface roughness data were analyzed. The color difference (ΔE) from after-staining protocol to different tooth brushing cycles (1,2,3) showed no significant difference on each cycle between the tested groups (p >0.05). While for color difference (ΔE) from baseline to the last tooth brushing cycle 3, the difference between groups was statistically significant where group II, sea salt-lemon-based toothpaste, had a significantly lowest (ΔE 00) value (p <0.001) indicating more whitening effect in relation to others. However, a significant increase in surface roughness was present in all tested groups (p <0.001); meanwhile, there was no significant difference between tested groups (p >0.05). After three tooth brushing cycles, none of the natural whitening toothpastes or conventional toothpastes produced had effective whitening results nor completely removed the stains back to the initial baseline tooth color. Sea salt-lemon-based whitening toothpaste had a whitening effect better than the charcoal-based toothpaste. All of the tested toothpastes increased the degree of surface roughness. Charcoal and sea salt-lemon-based whitening toothpastes do not guarantee to whiten nor completely remove the stains back to normal and their effects on enamel surface roughness should be highly clinically considered and managed.

A green approach to clean iron stains from marble surfaces

In the field of cultural heritage restoration, the removal of iron corrosion stains is a difficult problem to deal with, especially in stone materials. Many studies in recent years have been aimed at finding simple and reliable methods using non-toxic chelating compounds. The search for natural non-toxic compounds is therefore of great relevance, especially in the conservation of cultural heritage, where the use of toxic chemical compounds often involves risks for the environment and human health. Following this trend, the purpose of this preliminary work was to verify the use of two proteins, Lactotransferrin (Ltf) and Ovotransferrin (Ovt), for the removal of iron-based stains on marble surfaces. The two proteins, whose high affinity for iron “in vivo” has been widely documented, were extracted from their natural matrices. The protein extracts were then immobilized using a common cellulose pulp. The poultices obtained were spread on the surfaces of artificially stained marble specimens and, after a set time, were easily removed. The effectiveness of the removal, visually evident, was detected by spectrocolorimetry and image analysis. The surface analyses, before and after the treatment, carried out by X-ray photoelectron spectroscopy (XPS), confirmed that both proteins have a selective and effective complexing capacity for the ferric ions of rust stains.

Esthetic treatments for white and yellow/brown enamel stains

In order to solve the dental aesthetic pattern of a patient, who has dental stains on the enamel surface, we carried out this case report where are presented the steps employed for bleaching of teeth with superficial yellow/brown enamel stains with carbamide peroxide and micrometric removal of hard white enamel stains using the enamel microabrasion technique. The worn of dental surface during enamel microabrasion technique was measured with a digital analysis, using a intraoral scanner. It was observed a surprisingly esthetic outcome as the superficial enamel stains were camouflaged by the at-home dental bleaching. Only the superficial white enamel stains that remained evident were removed by enamel microabrasion technique with a minimal average wear of 118 um of the dental enamel on all anterior teeth, showing to be a conservative technique. Dental bleaching can solve the discoloration of vital teeth, such as the superficial yellow/brown hard enamel stains, as well as can mask the superficial white enamel stains. But when necessary, enamel microabrasion technique is an effective minimally-invasive option that can also be adopted.

Enzymatic bioprospecting of endophytic Aspergillus niger isolated from Albizia lebbeck (L.) Benth

Endophytic fungi reside inside plants in a mutualistic relationship with the host and produce numerous bioactive compounds, including extracellular enzymes. A rich diversity of endophytic fungi associated with the medicinal plant Albizia lebbeck (L.) Benth was bio-prospected in the present study. Thirty-three isolates obtained from the plant were assessed for secretion of six different extracellular hydrolytic enzymes. The results showed that 38%, 9%, 69%, 16%, 38%, and 13% of the endophytic isolates could produce amylase, protease, lipase, laccase, cellulase, and gelatinase enzymes, respectively. Overall, 78% of the isolates showed positive results for one or the other enzyme. Aspergillus niger (Isolate 8) isolated from the bark proved to be most efficient in producing all the enzymes and was further exploited for various applications. The crude fungal amylase of the isolate helped in 39.08% reduction in biochemical oxidation demand (BOD) of municipal wastewater. Effective blood stain removal from the white cotton cloth was achieved when crude protease was used in combination with detergent. 13.29% biodegradation of vegetable oil was observed using fungal lipase. Dye decolorization of methylene blue (71.65%) and methyl orange (56.53%) was observed by fungal laccase. Saccharification of bagasse (83.94%) and paper (64.93%) was achieved by using fungal cellulase. Complete extraction of silver from waste X-ray films was achieved by crude gelatinase. The results obtained in the present study can further be strengthened using purified enzymes.

Valorization of corn cobs for xylanase production by Aspergillus flavus AW1 and its application in the production of antioxidant oligosaccharides and removal of food stain

Xylanases are hemicellulolytic enzymes specifically catalyze xylan hydrolysis that constitutes the most abundant polysaccharide in the hemicellulose fraction of the lignocellulosic biomasses. The effective conversion of these biomasses to valuable commodities required the use of economic effective biocatalysts . In this study, xylanase production was performed by corn cobs fermentation using Aspergillus flavus AW1 in which the highest productivity was 356.36 U/g dry substrate. The partially purified enzyme was aflatoxin-free as estimated by high performed liquid chromatography . The enzyme was optimally active over a wide pH range from 5.5 to 7.5. Additionally, it was optimally active at temperature of 55 °C and at 60 °C it possessed 95% of its maximum activity. The enzyme half-lives were estimated as 83.81 and 44.69 min at 55 and 60 ° C, respectively. The V max and K m for the purified enzyme fraction were 250 U/mg protein/min and 5.55 mg/mL, respectively. Moreover, beech wood xylan hydrolysis as well as the hydrolysis of the hemicellulosic fraction of corn cobs was examined by applying the produced enzyme. The obtained results indicated hydrolysis percentage values of 39 and 19% for beech wood xylan and the hemicellulosic fraction of corn cobs, respectively with the release of a mixture of xylooligosaccharides confirmed by thin layer and high performed liquid chromatography analysis. The antioxidant activities for the dried oligosaccharide mixtures were estimated by scavenging activity of 1,1-diphenyl-2-picrylhydrazyl free radical. Finally, the efficiency of the purified enzyme fraction in the removal of mango stain was investigated in comparison to the commercial detergent. • Xylanase was produced by solid state fermentation of corn cobs using Aspergillus flavus AW1. • The partially purified enzyme was thermo-active and possessed high affinity toward beech wood xylan. • The enzyme was applied for the removal of food stain and production of xylooligosaccharides. • The produced xylooligosaccharides possessed antioxidant activity.

Preliminary study for the evaluation of a pulsed coaxial plasma gun for removal of iron rust stain from bone artifacts

• Iron stain is one of the most crucial aspects of archaeological bone deterioration. • Chemical reaction between bones and the iron stain was explained. • The coaxial plasma cleaning was used for the first time for removal of iron stain. • The efficiency of plasma cleaning depended on power, numbers of pulses, and etc. • Analytical methods were utilized for the evaluation of the coaxial plasma cleaning. The pulsed coaxial plasma gun is an effective and fast way to remove stains found on the surface of cultural heritage materials. Invisible oil films, dust deposition, corrosion products, or other contaminants can be cleaned by plasma. Iron stain can be found on bone when it is in direct contact with the corroded iron object or in proximity to the corrosion products in the soil. This study aims to evaluate the removal of iron stain from the surface of bone by using Pulsed coaxial plasma. Different parameters of pulsed plasma have been evaluated to reach the best condition of the treatment. Pulsed coaxial plasma was applied to modern bone samples artificially stained with ferric hydroxides. Analytical techniques used to evaluate the iron stain removal were digital microscope, SEM-EDX, FTIR, color measurement by UV spectrophotometer, AFM, pH value, and contact angle measurement. The results indicated that the coaxial plasma is highly effective for iron stain removal and does not affect treated bones. The best cleaning was performed by pulsed argon plasma at 50 pulses, pressure of 0.2 mbar, 0.5 cm distance, and 3kV plasma power.

&lt;strong&gt;Effectiveness of green tea, bay leaf, and lime peel extracts as toothpastes active agents for extrinsic stain removal on teeth, artificial teeth, and denture base&lt;/strong&gt;

Introduction: Tea consumption causes extrinsic stain formation on teeth and denture surfaces, affecting personal appearance. Herbal plants extract such as green tea, bay leaf, and lime peel are potentially active agents for extrinsic stain removal. This study aimed to analyse the effectiveness of green tea, bay leaf, and lime peel extracts as toothpaste active agents for extrinsic stain removal on teeth, artificial teeth, and denture base. Methods: Twenty-five post-extracted human permanent central incisors, 25 artificial teeth, and 25 heat polymerised acrylic resin denture base (20x20x10mm) were divided into three treatment groups and two control groups. Pictures of all specimens were taken before and after stain induction and after brushing. All specimens were immersed in a tea solution made from 2 grams of tea and 100ml of 100°C boiled water to induce extrinsic stain. The immersion process was repeated every 24 hours for seven days. All specimens were then brushed using an automatic toothbrushing machine for 70 seconds on each surface, 200 grams loads, and five speeds/second. Toothpaste used for brushing were three different active agent toothpaste (treatment groups), no active agent toothpaste, and commercial whitening (control groups). Colour index analysis of the specimen pictures computerised by CIELAB method. The data were analysed by one-way ANOVA (α=0.05). Results: Green tea, bay leaf, and lime peel extract toothpaste and positive control had higher L-values of extrinsic stain removal than essential toothpaste on all specimens. There was a significant difference between green tea, bay leaf, and lime peel extract toothpaste and negative control toothpaste (p&lt;0.05), while no significant difference was found when compared to the positive control toothpaste (p&gt;0.05). Conclusion: Green tea, bay leaf, and lime peel extract toothpaste are effective as extrinsic stain removal on teeth and acrylic resin denture base because of abrasive materials that work together with the active agents such as epigallocatechin-3-gallate (EGCG) in green tea, eugenol in bay leaf, and naringin in lime peel.

EFFECTIVITY OF MULTIFUNCTION HERBAL TOOTHPASTE CONTAINING BAY LEAF (EUGENIA POLYANTHA WIGHT) EXTRACT AS EXTRINSIC STAIN REMOVAL ON TEETH AND DENTURE

Background: White teeth colour influence aesthetical appearance which leads to self-confidence and quality of life. Extrinsic stain is the most common aetiology of teeth discoloration, which caused by widely consumed products such as tea, coffee, and tobacco. It also formed on denture and cause negative impacts. Commercial extrinsic stain removal toothpastes only indicated for teeth and contain chemical active agent with undesirable effects. Aim of this study is to determine effectivity of bay leaf (Eugenia polyantha Wight) extract as toothpaste active agent for extrinsic stain removal on teeth and dentures.Method: Pictures of teeth, artificial teeth, and acrylic resin base taken before experiment, after stain induction (using 25g of tea in 100ml of 100oC water for 7 days, tea solution replaced every 24 hours), and after brushing. Toothpastes used for brushing were no active agent basic formulation toothpaste, bay leaf extract toothpastes at 5%, 10%, 15% concentrations, and commercial stain removal toothpaste as positive control. Specimens were brushed using automatic brushing machine for 70 seconds/surface, using 250g load, and speed 5 movements/sec. Colour index analysis of specimens’ pictures were computerized and analysed using CIELAB method to obtain L-value of extrinsic stain removal. Data analysis performed using one-way ANOVA (α=0.05).Result: There is effect of toothpaste containing bay leaf extract 15% to remove extrinsic stain both on teeth, artificial teeth, and acrylic resin base according to one-way ANOVA.Conclusion: Bay leaf extract is effective and potential to be used as toothpaste active agent for extrinsic stain removal on teeth and denture.

Simultaneous and Efficient Removal of Oleophilic and Hydrophilic Stains from Polyurethane by the Combination of Easy-Cleaning and Self-Cleaning.

The simultaneous and efficient removal of oleophilic and hydrophilic stains from polyurethane (PU) is realized by combining the easy-cleaning from the hydrophilic thermoresponsive hydrogel coating containing acrylamide (AAm), gum arabic (GA), and (ethylene glycol) methyl ether methacrylate (OEGMA300) P(GA/AAm/OEGMA300) and the self-cleaning from the embedded nonmetallic photocatalyst g-C3N4. Due to the existence of strong hydrogen bonds between the hydroxyl groups in the hybrid hydrogel coating and the hydroxyl/carboxyl groups in the plasma-treated PU, the hybrid hydrogel coating is very stable on PU. Simultaneously, the acrylamide network in the hybrid hydrogel coating enhances its mechanical strength. Because the transition temperature of OEGMA300 is well above the room temperature, the cross-linked coating remains hydrophilic in ambient conditions. Thus, oleophilic stains, such as oil and grease, can be easily removed from the coating surface. In addition, the embedded photocatalyst g-C3N4 in the hybrid hydrogel coating introduces the extra capability of decomposing organic compounds under sunshine, which favors the removal of hydrophilic stains such as dyes and wines. After sunlight illumination and simply rinsing with water, both hydrophilic and oleophilic stains can be easily removed. Moreover, this joint cleaning performance can work for a long time. Even after four consecutive cycles, both the easy-cleaning to oleophilic stains by the hydrophilic hydrogel surface and self-cleaning to the hydrophilic stains by the embedded g-C3N4 remain unchanged.

Stabilisation of Ozone in Water for Microbial Disinfection

In current times of increasing global decontamination concerns, sustainable and environmentally-friendly technologies that possess rapid and effective disinfection capabilities are necessary for public health and safety. In this study, we evaluate the potential of ozone-based technology to reveal its immense potential in disinfection applications. Ozonated water generated by an electrolytic method was utilised to quantify ozone retention as a function of mineralogical composition for microbial decontamination. The impacts of temperature and detergent concentration on ozone concentration are critically analysed, as well as ozone’s decomposition and stain removal characteristics. In addition, fabric swatches inoculated with known concentrations of environmental microbes (Escherichia coli, Staphylococcus aureus, Candida albicans, and Aspergillus fumigatus) are washed with ozonated water to ascertain the impact of wash duration on bacterial removal efficiency. The results show significant improvement in the stability and retention potential of ozone in mineral water at low temperature and in the presence of a detergent. The experiments demonstrate first-order decomposition kinetics of ozone in aqueous formulations. The disinfection potency of ozone is also substantiated by a significant removal of microbiota on the fabric utilised (up to 7 log reduction for the bacteria analysed), thus making it effective for sterilisation applications. This also reduces the need for toxic chemicals or chemicals with toxic by-products (e.g., chlorine) for large-scale decontamination operations in various industries.

Evaluation of the time-dependent efficacy of commercial denture or orthodontic appliance cleansers: An in vitro study.

The aim of this study was to evaluate the antimicrobial, stain and protein removal efficacy of denture or orthodontic appliance cleansers using in vitro test methods. Experimental cleansers were applied for experimental time in each evaluation method. To evaluate the microorganism removal efficacy, C. albicans and S. mutans removal rate was calculated from the specimen surface. Stain and protein removal rate was calculated using the spectrophotometer. Experimental cleansers significantly affected the microorganism removal rate for both C. albicans and S. mutans, as well as the stain and protein removal rates, at each experimental time (p<0.05). As the application time increased, the stain and protein removal rates of all experimental cleansers significantly increased (p<0.05). The present study provided in vitro evaluation methods to assess the efficacy of denture or orthodontic appliance cleansers. Also, manufacturers and researchers can predict clinical outcomes and ensure proper hygiene management of dentures or orthodontic appliances.

Outcomes of implementation of the FilmArray meningoencephalitis panel in a tertiary hospital between 2017 and 2020.

BackgroundAcute meningoencephalitis is encountered commonly in the acute hospital setting and is associated with significant morbidity and mortality, in addition to significant healthcare costs. Multiplex PCR panels now allow syndromic testing for central nervous system infection. The BioFire® FilmArray® Meningoencephalitis (ME) allows testing of 14 target pathogens using only 0.2mls of cerebrospinal fluid (CSF). We conducted a retrospective observational study to assess the performance of the assay and secondarily to observe the clinical utility of negative results by comparing clinical outcomes of aseptic meningitis to bacterial and viral meningoencephalitis.MethodsData for CSF samples tested using the FilmArray ME panel from October 2017 to October 2020 were analysed. Detection of bacterial and viral targets was analysed. Admission to critical care area, 90-day readmission rates, average length of stay and 30-day and 90-day mortality were analysed for three groups with following diagnoses: bacterial meningitis, viral meningoencephalitis, or aseptic meningitis.ResultsFrom October 2017 to October 2020, 1926 CSF samples were received in the Clinical Microbiology laboratory. Of those, 543 CSF samples from 512 individual patients were tested using the FilmArray ME panel. Twenty-one bacterial targets and 56 viral targets were detected during the study period. For viral targets, the cumulative specificity was 98.9% (95% confidence interval: 93.1–99.9) when compared to the reference laboratory methods. The outcomes for 30- and 90-day mortality of the aseptic meningitis group were non-inferior relative to the viral meningoencephalitis and bacterial meningitis group. Patients with bacterial meningitis had a longer average length of stay. Aseptic meningitis was associated with a higher 90-day readmission rate than the other 2 groups, but without statistical significance.ConclusionIn our hands, implementation of the FilmArray ME panel was relatively straightforward. We experienced a transition in our workflow processes that enabled streamlining of CSF diagnostics and the safe removal of Gram staining in those samples being tested by this molecular assay. Coupled to this improvement, there was a positive clinical impact on patient care due to rapid turnaround time to results.

Production, partial purification and efficacy of keratinase from Bacillus halotolerans L2EN1 isolated from the poultry farm of Himachal Pradesh as a potential laundry additive

To augment the keratinolytic ability of Bacillus halotolerans L2EN1 isolated from the poultry farm (Nahan, District Sirmour) of Himachal Pradesh, different cultural conditions were optimised using One Variable at a Time (OVAT) approach accompanied by Response Surface Methodology (RSM). Optimisation (OVAT) results revealed that after 3rd day of incubation, maximum enzyme activity was attained at 45 °C, pH 11.0 with 12.5% of inoculum size in the presence of Mn2 + and EDTA in the production medium. Sucrose (1.5%) and yeast extract (2.0%) were observed to be best carbon and nitrogen sources, respectively. A significant increase of 73.19 per cent in the keratinase activity was observed using Central Composite Design (CCD) of RSM. The SDS-PAGE results revealed that crude keratinase is a heterotetramer made up of four polypeptide chains with molecular weights of 17, 37, 40 and 60 kDa. Partial purification by 90 − 100 percent ammonium sulphate gave maximum keratinase production of 22.66 U/mL with purification of 1.68 and yield of 11.47 per cent. The enzyme showed compatibility with different commercial detergents and retained its activity in the order: Reshma (97.77%) > Speed (93.44%) > Tide (79.93%) >Ariel (70.18%) > Surf excel (67.98%) at 50 °C after 1 h of incubation. Wash performance analysis demonstrated that washing with tap water at 18, 28, 35 and 45 °C for 30, 45 and 60 min removed some amount of blood stains from the cotton cloth pieces. However, replacement of detergent’s enzyme (Reshma) with crude keratinase achieved complete blood stain removal under same conditions, suggesting its suitability as a potential cleaning additive in detergents for the removal of blood (proteinaceous) stains for long washing cycles (1 h).

Effectiveness of denture cleansers on flexible denture base resins in the removal of stains colored by food colorant solution: An in vitro study.

The aim of the study was to compare the efficiency of three denture cleansers (Valclean, Polident and Clinsodent) in removal of turmeric stains from flexible denture base resins. In vitro - comparative study. A total of 45 specimens of flexible denture base resins were fabricated and subjected to baseline colour measurements using spectrophotometer. Specimens were stained with turmeric and colour measurements of stained specimens were made. All the stained specimens were divided into three groups (n = 15) for removal of stains with three denture cleansers: Valclean, Polident, Clinsodent and colour measurements of cleansed specimens were made. The colour measurements (ΔE) values obtained were collected and statistical analysis was done. One-way ANOVA (Analysis of Variance), Tukey's post hoc test. One way ANOVA test revealed that the mean colour difference of three groups were statistically different with P value < 0.001. A further Tukey post hoc test revealed that the Valclean group had lesser mean scores than Polident and Clinsodent group. It was concluded that Valclean showed statistically significant greater stain removal efficiency than Polident followed by Clinsodent.

Combined use of baking soda and electric toothbrushing for removal of artificial extrinsic stain on enamel surface: An in vitro study.

BackgroundThis study aimed to investigate the combined effect of baking soda and electric toothbrushing on the removal of artificial extrinsic stain in vitro. Material and MethodsFlat enamel surfaces of 15 bovine incisors were artificially stained with 10% citric acid / 3% ferric chloride solution followed by 1% tannic acid solution. These specimens were randomly divided into three groups (n = 5) – Group S+B: brushing with an electric toothbrush and baking soda, Group S+C: brushing with an electric toothbrush and fluoride dentifrice, Group S: brushing only with an electric toothbrush. Color values (L*, a*, and b*) and surface roughness were measured before and after brushing (after 1, 2, 3, and 5 min). The data were statistically analyzed using two-way analysis of variance and Tukey’s honest significant difference test as a post hoc test (p< 0.05). ResultsThe L* value of Group S+B increased over time, and was significantly different between before brushing and at 5 min (p< 0.05). A significant difference in the ΔE* value of Group S+B was found at 5 min (p< 0.05). However, no significant difference was found in the ΔE* values of Group S+C and Group S. No significant differences in Ra were found in any of the groups. ConclusionsThe results of this study suggest that the combined use of baking soda and electric toothbrushing has an excellent stain-removing effect compared with electric toothbrushing with a fluoride dentifrice. Additionally, the changes in surface roughness were similar to the changes caused by the use of general dentifrices. Key words:Baking soda, dentifrice, extrinsic stain removal, color change, surface roughness.

Comparative assessment of the efficacy of low concentration bleaching agents using quantitative light induced fluorescence in removing stains: An In vitro study.

Tooth discoloration has become a common esthetic problem in recent years. Removal of stains by bleaching is well-documented. Low concentration home bleaching products are available in market in different forms and concentrations. The aim of this study is to evaluate and compare the efficacy of low concentration commercially available home bleaching products (whitening strip, gel, and mouthwash) in removing stains and whitening the tooth using clinical and digital methods. Sixty permanent enamel samples mounted in an acrylic block were artificially stained and randomly divided into four groups. Negative control, 15 % Carbamide peroxide gel group, 2% Hydrogen 16 peroxide mouthwash group and 6% Hydrogen peroxide strip group respectively. The samples were bleached with respective agents according to the manufacturer's instructions. The efficacy on 7th and 14th day was evaluated clinically (SGU change), photographically (ΔE), and using quantitative light-induced fluorescence (ΔF). The data were analyzed using paired t-test and analysis of variance. Postbleaching, 6% hydrogen peroxide strips and 15% carbamide peroxide gel showed maximum improvement (ΔΔF - 15.73 and 11.89, ΔE - 19.8 and 18.9, respectively) when compared to 2% hydrogen peroxide mouthwash and negative control group (ΔΔF - 9.68 and 6.59, ΔE - 15.04 and 9.44, respectively). The difference was statistically significant (P = 0.001). 6% hydrogen peroxide strips and 15% carbamide peroxide gel showed maximum improvement in stain removal and tooth whitening however, the strips showed better efficacy than the gel. Strips have the added advantage of lesser contact period, less salivary dilution, and no gingival contact. Therefore, strips can be a better alternative for gels and mouthwashes.

Biochemical characterization of protease enzyme extracted from different plant leaves and seeds: Destaining efficiency of enzyme for stain removal

Enzymes have replaced harsh chemicals to a great extent due to their biodegradable nature and greatly contributed to environmentally adopting clean and green technology. At present, proteases capture 65% of the total worldwide enzyme market due to their catalytic function which hydrolyze peptide bonds of proteins.The present study aimed to isolate and characterize the protease enzymes extracted from eight different plant sources i.e., six leguminous seeds like soybean (Glycine max), ground nut (Arachis hypogaea), black gram and white gram (Cicer arietinum), urad (Vigna mungo), moong (Vigna radiata) and two different plant leaves i.e., curry (Murraya koenigii) and coriander (Coriandrum sativum). Stain removal efficiency and detergent compatibility of all plant proteases were also studied. The results indicated that groundnut had highest protease activity (0.71U/ml) and highest specific activity (0.24U/mg) under the 50% salt saturation while the highest Kmvalue (0.034 mM/L) was observed in white gram seed and Vmaxvalue (4.60 |jM/sec) was observed in soybean seed. The pH of seed protease ranged from 6–10 with the 9 optimal pH while curry leaves and coriander leaves showed 7 and 9 optimal pH, respectively. The optimal temperature of proteolytic activity was observed at 40°C in all plant sources. The destaining properties of plant protease enzymes were observed better against different stains like roli,turmeric powder, tea,ink,chandan powder, methylene blue dye and synthetic dye (Pink colour) than the detergent. The removal efficiency of the enzyme was increased with the detergent.Thus, the removal efficiency of detergent is enhanced by using plant proteases which may be recommended in the detergent formulation as additives due to their broad pH range and thermal stability as well as clean and green technology.