Effect of three different conditioning agents on cavosurface microleakage and bond strength of glass ionomer restorations – An in vitro study

Aim: This study aimed to investigate the conditioning effects of phosphoric acid/5.25% sodium hypochlorite (NaOCl) mixture, 2% chlorhexidine (CHX) digluconate, and 10% polyacrylic acid on cavosurface microleakage and bond strength of glass ionomer (GI) restorations. Materials and Methods: Out of 68 extracted premolars, 34 teeth were selected for microleakage and 34 for bond strength evaluation. The samples were divided into the following four groups. Group 1: pretreatment with 50/50 volume% mixture of 5.25% NaOCl solution and 37% phosphoric acid (H3PO4), Group 2:pretreatment with 2% CHX digluconate, Group 3: pretreatment with 10% polyacrylic acid (positive control), and Group 4: no pretreatment (negative control). All the samples were then restored with glass ionomer cement (GIC). Microleakage was evaluated using a stereomicroscope and rhodamine-B dye penetration test. For bond strength, flat dentin surface was exposed and pretreated as mentioned previously and restored with GIC and was evaluated using universal testing machine. Results: Among all the four groups, Group 1 showed least microleakage and highest bond strength when compared with other groups. Whereas the Group 4 samples which were not pretreated with any of the conditioning agent showed the least shear bond strength with greatest cavosurface microleakage when compared to the groups which were pretreated with the conditioning agents. Conclusions: A combination of 50/50 volume % mixture of 37% H3PO4 and 5.25% NaOCl can be a good choice for surface pretreatment of GI restorations.

The effect of deproteinization methods on the properties of glucosamine hydrochloride from shells of white leg shrimp (Litopenaeus vannamei) and black tiger shrimp (Penaeus monodon) / Efeito de métodos de desproteinização nas propriedades do cloridrato de glucosamina de cascas de camarão de pernas brancas (Litopenaeus vannamei) e cascas de camarão de tigre preto (Penaeus monodon)

ABSTRACT: The effect of methods to remove protein content on the properties of glucosamine hydrochloride from the shells of white leg shrimp (Litopenaeus vannamei) and black tiger shrimp (Penaeus monodon) was investigated. Chitin from shrimp shells was obtained by demineralization in 6% HCl for 12h, deproteinization by two different methods (first group soaked in 8% NaOH for 36h and second group treated in Alcalase enzyme at the concentration of 0.2% for 36h). Two group samples were converted to glucosamine hydrochloride by soaking in 36.76% HCl solution for 5h at 85 °C. The results of fourier transform infrared spectroscopy (FTIR), solubility and recovery yield analysis showed that deproteinization methods did not significantly affect the properties of glucosamine hydrochloride. However, glucosamine hydrochloride from white leg shrimp shells contained higher recovery yield and solubility than black tiger shrimp shells.

RESUMO: Investigou-se o efeito de métodos para remover o conteúdo de proteínas nas propriedades do cloridrato de glucosamina das conchas de camarão de pernas brancas (Litopenaeus vannamei) e camarão de tigre preto (Penaeus monodon). A quitina das cascas de camarão foi obtida por desmineralização em HCl a 6% por 12 h, desproteinização por dois métodos diferentes (primeiro grupo embebido em NaOH a 8% por 36 h e segundo grupo tratado na enzima Alcalase na concentração de 0,2% por 36 h). Duas amostras de grupo foram convertidas em cloridrato de glucosamina por imersão em solução de 12M HCl por 5 h a 85 °C. Os resultados das análises de FTIR, solubilidade e rendimento de recuperação mostraram que os métodos de desproteinização não afetaram significativamente as propriedades do cloridrato de glucosamina. No entanto, o cloridrato de glucosamina de cascas de camarão de pernas brancas continha maior rendimento e solubilidade de recuperação do que as cascas de camarão tigre preto.

Enamel Deproteinization: Will It Save The Shear Bond Strength For The Sake Of Preventing White Spot Lesions? / Desproteinização do esmalte: salvará a resistência ao cisalhamento para prevenir lesões de manchas brancas?

Objective: This study attempted to investigate the effect of enamel deproteinization using citric acid, PEG 400 and NaOCL on the shear bond strength of orthodontic brackets to enamel using nano-silver modified resin for the prevention of white spot lesions. Material and Methods: 68 premolars were used in the study; nano-silver modified adhesive resin was used to bond orthodontic brackets to the enamel. Specimens were divided into 4 groups according to the applied surface treatment before bonding. Group I (control): acid etching with 37% phosphoric acid. Group II: deproteinization using 5.25% sodium hypochlorite (NaOCl) before acid etching. Group III:deproteinization using 10% citric acid before acid etching. Group IV:deproteinization using 5% polyethylene glycol (PEG 400) before acid etching. The specimens were then thermo- cycled for 6000 cycles. They were examined for surface roughness, shear bond strength and using electron microscope. Results: In both surface roughness and shear bond strength tests, Group III (citric acid) showed the highest values, followed by Group II (sodium hypochlorite); (p < 0.001). The least values were shown for Groups I (control) and IV (PEG 400), with no statistically significant difference between them (p = 0.948). SEM revealed etching pattern type 1 and 2 in the citric acid group while PEG 400 showed shallower micro- porosities. Conclusions: Deproteinization of enamel using either NaOCl or citric acid increased the bond strength of nano-sliver modified resin to enamel, with citric acid showing greater increase in bond strength. Deproteinization using PEG 400 did not increase the bond strength. (AU)

Objetivo: Este estudo buscou investigar o efeito da desproteinização do esmalte utilizando ácido cítrico, PEG 400 e NaOCl na resistência ao cisalhamento de braquetes ortodônticos ao esmalte usando resina modificada com nanoprata para a prevenção de lesões de manchas brancas. Material e Métodos: 68 pré-molares foram usados no estudo; resina adesiva modificada com nanoprata foi usada para colar os braquetes ortodônticos ao esmalte. Os corpos-de-prova foram divididos em 4 grupos de acordo com o tratamento de superfície aplicado antes da colagem. Grupo I (controle): condicionamento ácido com ácido fosfórico a 37%. Grupo II: desproteinização com hipoclorito de sódio a 5,25% (NaOCl) antes do condicionamento ácido. Grupo III: desproteinização com ácido cítrico a 10% antes do condicionamento ácido. Grupo IV: desproteinização com polietilenoglicol 5% (PEG 400) antes do condicionamento ácido. As amostras foram então termocicladas por 6.000 ciclos. Eles foram examinados quanto à rugosidade da superfície, resistência ao cisalhamento e usando microscópio eletrônico. Resultados: Nos testes de rugosidade superficial e resistência ao cisalhamento, o Grupo III (ácido cítrico) apresentou os maiores valores, seguido do Grupo II (hipoclorito de sódio); (p <0,001). Os menores valores foram apresentados para os Grupos I (controle) e IV (PEG 400), sem diferença estatisticamente significativa entre eles (p = 0,948). A microscopia eletrônica revelou padrão de ataque tipo 1 e 2 no grupo de ácido cítrico, enquanto PEG 400 mostrou microporosidades mais rasas. Conclusões: A desproteinização do esmalte com NaOCl ou ácido cítrico aumentou a força de união da resina modificada com nanoprata ao esmalte, com o ácido cítrico apresentando maior aumento na força de união. A desproteinização usando PEG 400 não aumentou a resistência de união. (AU)

Biotechnological recovery of chitin from crustacean waste / Recuperación biotecnológica de quitina de residuos de crustáceos

Abstract Reviews on biotechnological recovery of chitin from crustacean waste and other sources are acknowledged in the present review. Most of the reviews conclude that although important results on chitin recovery have been achieved, there is still a need for better approaches to improve operational conditions of deproteinization and demineralization processes, such as time, carbon source, pH (initial and during fermentation), volume of inoculum, temperature, among others, in order to apply at industrial level, a bioprocess commercially and environmentally cost/effective viable. The present review aims to gather the most updated available information about research on biotechnological methods to recover chitin from crustacean waste, studied during the past 10 years, focussing on conditions applied to deproteinization (DP) and demineralization (DM), particularly on bioprocessing times and microbial species.

Resumen Revisiones sobre recuperación de quitina a partir de residuos de crustáceos y otras fuentes usando biotecnología son reconocidas en el presente artículo. La mayoría de las revisiones concluyen que aunque se han logrado resultados importantes en la recuperación de quitina, todavía existe la necesidad de mejorar las condiciones operativas de los procesos de desproteinización y desmineralización, tales como el tiempo, la fuente de carbono, el pH (inicial y durante la fermentación), el volumen de inóculo y la temperatura, entre otros, para aplicar a nivel industrial un bioproceso que sea comercial y ambientalmente costo-beneficio viable. La presente revisión tiene como objetivo reunir la información más actualizada disponible sobre la investigación en métodos biotecnológicos para recuperar la quitina de los residuos de crustáceos, estudiada durante los últimos 10 años, centrándose en las condiciones aplicadas a la desproteinización (DP) y la desmineralización (DM), particularmente en los tiempos de bioprocesamiento y las especies microbianas involucradas.

Optimization and purification of extraction of polysaccharides from Anoecto-chilus roxburghii / 药学实践杂志

Objective To optimize the process of ultrasonic extraction of polysaccharide in Anoectochilus roxburghii and to investigate the method of protein removal. Methods The extraction rate of polysaccharide was used as the detection index. On the basis of single factor investigation, Box-Behnken experimental design and response surface method were used to optimize the three factors of material-liquid ratio, ultrasonic time and ultrasonic extraction temperature. The five deproteinization methods including Sevage reagent method, TCA method, salt method (NaOH-CaCl2 and NaOH-NaCl) and hydrochloric acid method were investigated with the retention rate of polysaccharide and protein removal rate. Results The optimal extraction conditions of polysaccharide from Anoectochilus roxburghii were as follows: liquid-to-solid ratio was 10∶1, extraction temperature was 48 ℃ and extraction time was 36 min with extraction 2 times, ultrasonic power was 300 W, the extraction rate was 13.13%. NaOH-CaCl2 deproteinized methods∶ the loss rate of polysaccharide was 18.74%, and the removal rate of protein was 95.62%. Conclusion Ultrasonic extraction is easy to operate, and the optimized extraction method can achieve a high extraction rate. NaOH-CaCl2 deproteinization methods can get high protein removal rate and polysaccharide retention rate. This method is suitable for the research and development of the active components of the polysaccharides from Anoectochilus roxburghii.

The effects of deproteinization and primer treatment on microtensile bond strength of self-adhesive resin cement to dentin / 대한치과재료학회지

The purpose of this study was to evaluate the effects of deproteinization and an additional primer treatment on the microtensile bond strength of a newly developed self-adhesive resin cement to dentin. The occlusal dentin of extracted human third molars was randomly divided into four groups according to the surface treatment: a control (CON) with no treatment; applying a deproteinizing agent (DPT) (5% sodium hypochlorite); using a primer (PRI) (G-CEM ONE Adhesive enhancing primer, GC); and applying a deproteinizing agent and a primer (DPT-PRI). Composite resin blocks with a disk shape (diameter, 10 mm; height, 4 mm) were bonded to the treated dentin using a self-adhesive resin cement (G-CEM ONE, GC). The specimens were sectioned into sticks with a cross-section of 1 mm² and tested to failure in tension mode at a crosshead speed of 1 mm/min. All groups showed a significantly higher microtensile bond strength compared to CON (p0.05). Within the limitations of this study, a deproteinizing agent or specific primer can enhance the microtensile bond strength of the self-adhesive resin cement to dentin. However, it is not recommended to use a primer in combination with the deproteinizing agents.

Research progress of the influence of sodium hypochlorite deproteinization on the bonding of brackets / 口腔疾病防治

@#It is difficult to avoid the shedding of brackets during orthodontic treatment, which may not only affect the orthodontic therapeutic effect but also prolong the orthodontic treatment duration. Sodium hypochlorite is a commonly used root canal irrigation agent in oral medicine and is seldom used in orthodontic treatment. Sodium hypochlorite on the enamel surface can strengthen the effect of etching by deproteinization to improve adhesion, which could reduce the probability of bracket shedding during orthodontic treatment. Therefore, this article reviews the effects of sodium hypochlorite on enamel.

A Modified Pretreatment with Deproteinization for Resin Infiltration in Early Childhood Caries / 대한소아치과학회지

This study aimed to evaluate surface morphology and resin tag penetration of resin infiltration into primary anterior teeth after enamel deproteinization with sodium hypochlorite (NaOCl) prior to phosphoric acid (H₃PO₄) etching.Ninety primary anterior teeth with non-cavitated caries lesion were devided five groups according to enamel pretreatment as follows, group I-15% hydrochloric acid (HCl) 2min. ; group II-5.25% NaOCl 1min., 35% H₃PO₄ 1min. ; group III-5.25% NaOCl 2min., 35% H₃PO₄ 1min. ; group IV-5.25% NaOCl 1min., 35% H₃PO₄ 2min. ; group V-5.25% NaOCl 2min., 35% H3PO4 2min. Fifteen teeth were examined etched surface structure using field emission-scanning electron microscope. Seventy five teeth were infiltrated with resin, maximum penetration depth and percentage penetration were analysed using dual fluorescence confocal microscopy.As the application time of NaOCl increased, ratio of enamel type I, II were increased. Percentage penetration (PP) was higher in group V than group II, III (p < 0.05). PP of group IV, V did not show any differences.Non-cavitated caries of primary anterior teeth can be treated with resin infiltration. Enamel deproteinization with NaOCl prior to 35% H3PO4 etching could be an alternative of 15% HCl etching in resin infiltration.

Enhancement of protease production by the optimization of Bacillus subtilis culture medium

Aims: Traditionally, crustacean wastes have been managed by using acid and alkali which leads to major environmental issue. However, over the recent years microbial fermentation has gained its way whereby producing similar effects as chemical treatment and a higher quality product can be obtained. Extracellular protease from Bacillus subtilis was used further by optimizing its culture medium to enhance protease production. Methodology and Results: The culture media was optimized with 4 various sources; Shrimp Crab Shell Powder (SCSP), nitrogen sources, inorganic salts, and carbon sources. It was found that culture media supplemented with 9% SCSP, 3% yeast extract, 1% sodium chloride and 9% glucose augmented protease activity up to 565.80 ± 19.41 U/mL compared to the un-optimized media (170.57 ± 6.75 U/mL). By using this optimized media, the ability and efficiency of B.subtilis in a period of 6 days was investigated whereby acid treated shrimp shells (ATSS) and raw shrimp shell powder (RSSP) were used in substitution of SCSP. In a period of 6 days, the protein content in both ATSS and RSSP was found to have been removed up to 60% and 42% respectively. However deproteinization was found to be more efficient in RSSP with the ratio of tyrosine to protein remained constantly high throughout the 6 days period. Conclusion, significance and impact of study: A better, more efficient and environmental friendly method is continuously being improvised to manage shrimp wastes with the use of microbes.

Bioremediation of shrimp biowaste by using natural probiotic for chitin and carotenoid production an alternative method to hazardous chemical method.

The production of chitin and carotenoids from shrimp biowaste by using natural probiotic has been studied. The fermentation studies were determined by varying inoculum levels from 1 to 10%, glucose concentration from 0 to 15% and incubation time 0 to 72 hours. The maximum decrease of pH 3.01 and an increase of total titrable acidity (TTA) 2.715 were obtained for incubation period of 72hours with 5% inoculum level and 15% glucose concentration. The effect of fermentation by natural probiotic on the production of chitin (as indicated by deproteinization and demineralization efficiency) and recovery of carotenoids were also studied. Deproteinization of 89% and demineralization of 69% were obtained by fermentation of shrimp biowaste with natural probiotic. The carotenoid and chitin recovery from shrimp biowaste was 72.6% and 5.65% respectively. As the process by using natural probiotic was found to be efficient, economical, it becomes an alternative method for hazardous chemical method used in extraction of chitin and carotenoids.

Study on the Extracting and Purifying Process of Achyranthes Bidentata Polysaccharides / 中国药房

OBJECTIVE:To study the extracting and purifying process of Achyranthes bidentata polysaccharides(ABP). METHODS:Crude polysaccharide was obtained by extracting ABP raw material by water decocting method.The Crude polysaccharide was purified(deproteinization,desalination and alcohol precipitation) to obtain ABP.The content of total polysaccharide was taken as an evaluation index to optimize the optimum conditions of extracting and purifying.RESULTS: The optimum water decoction conditions were as follows:ABP raw material was extracted three times (2 h/time) by adding 10 times amount of water.As for the deproteinization process,TCA(trichloracetic acid) method was superior to Sevage method and tannic acid method;Desalination by molecular sieve was superior to that by dialysis method; and alcohol precipitation was performed with 80% alcohol.CONCLUSION:ABP can be prepared by water decoction,deproteinization,desalination and alcohol precipitation of its raw material.