Impacto da biomodificação com extrato de Schinopsis brasiliensis (Braúna) na resistência máxima à tração de um selante resinoso / Impact of biomodification with Schinopsis brasiliensis (Braúna) extract on the maximum tensile strength of a resinous sealant

Introdução: Os selantes resinosos apresentam uma alta taxa de sucesso na prevenção da cárie dentária, porém não possuem atividade antibacteriana, sendo a incidência de novas lesões um dos fatores que ainda causam impacto negativo na qualidade de vida das pessoas. A biomodificação com o extrato da Schinopsis brasiliensis (Braúna) pode ser uma alternativa no aperfeiçoamento das suas características clínicas. Objetivo: Avaliar se a biomodificação do selante Fluroshield® com diferentes concentrações do extrato do caule do Schinopsis brasiliensis afeta sua resistência máxima à tração (resistência coesiva). Metodologia: O extrato foi pesado em balança analítica e misturado ao selante nas concentrações de 0 mg/mL (controle), 20 mg/mL, 5 mg/mL e 1,25 mg/mL e espatulado por 1 min., utilizando uma placa de vidro. Amostras em formato de barra com dimensões de 8 mm (comprimento) x 2 mm (largura) e 1 mm (espessura) foram confeccionadas (n=3) e submetidas ao teste de resistência máxima à tração em máquina de ensaio semi universal (OM 100). Antes da fixação delas nas placas de ensaio, a medida da secção transversal (mm2) foi aferida com paquímetro. Os dados foram obtidos em Kgf e transformados em MPa. A análise estatística foi realizada pelo teste de Kruskal-Wallis (p<0,05). Resultados: A resistência máxima à tração dos grupos em mediana (mínimo-máximo) dos grupos 0 mg/mL (controle), 20 mg/mL, 5 mg/mL e 1,25 mg/mL foi, respectivamente, 56 (29-56), 53 (45-60), 48 (46-62) e 61 (38-64). Não houve diferenças estatisticamente significativas entre os grupos (p=0,8). Conclusão: A adição do extrato do caule de Schinopsis brasiliensis não reduziu a resistência máxima à tração do selante Fluroshield® (AU).

Introduction: Resin-based sealants have a high success rate in preventing dental caries, but they do not have antibacterial activity, so that a high incidence of caries lesions is observed, which negatively impacts on health quality. The biomodification with the Schinopsis brasiliensis (Braúna) stem extract may be an alternative to improve its clinical characteristics. Objective: To evaluate if the biomodification of the Fluroshield® sealant with different amounts of Schinopsis brasiliensis affects its ultimate tensile strength. Methods: The extract was weighed on an analytical balance and mixed with the sealant in different concentrations: 0 mg/mL (control), 20 mg/mL, 5 mg/mL and 1.25 mg/mL by mixing for 1 min. Bar-shaped specimens with dimensions of 8 mm x 2 mm x 1 mm were prepared (n=3). The ultimate tensile strength was measured using a microtensile machine (OM100). Before testing, the sectional area (mm2) was obtained with a caliper. Data were obtained in Kgf and transformed into MPa. Statistical analysis was performed using the Kruskal-Wallis test (p<0.05). Results: The maximum tensile strength in median (minimum-maximum) of the 0 mg/mL (control), 20 mg/mL, 5 mg/mL and 1.25 mg/mL groups was, respectively, 56 (29-56), 53 (45-60), 48 (46- 62) and 61 (38-64). There were no statistically significant differences among the groups (p=0.8). Conclusion: The addition of Schinopsis brasiliensis stem extract did not decrease the ultimate tensile strength of the Fluroshield® sealant (AU).

Alginate with citrus pectin and pterostilbene as healthy food packaging with antioxidant property.

A new type of film packaging made from natural polysaccharide materials, with its environmental safety and friendliness, is considered as a potential substitute for plastics. Novel polysaccharide composite films based upon citrus pectin (CP) and sodium alginate (SA) were successfully prepared and characterized, containing pterostilbene (PTE) at various concentrations (0.2, 0.4, 0.8, 1.6, 3.2 mM). The rheological analysis displayed that all film-forming liquids performed no gelation behavior with G" > G' at low frequency and weak gelation with G" < G' at high frequency. The SA-CP films had good tensile strength (TS) and elongation at break (EB), while adding PTE as an antioxidant to the film reduced both the values. Of note, the SA-CP films with PTE had better moisture resistance than that of the pure SA-CP films, which was related to the changes of its microstructure. The increased roughness of the films containing PTE was observed by microscope. After calcium chloride cross-linking, the water solubility of the films was reduced, while its thermal stability was improved. Notably, the accretion of PTE expressively enhanced the antioxidant properties of the SA-CP films. Thus, the SA-CP composite films containing PTE could be utilized as an excellent antioxidant packaging material.

In vitro comparison of the tensile strength of elastomeric ligatures exposed to Povidone Iodine 1%, Chlorhexidine 0.02%, and hydrogen peroxide 5.

OBJECTIVE: In orthodontic patients using any chemical substances in oral environment could change the elastomeric properties of their appliances. Since the beginning of the SARS-CoV-2 pandemic, efforts have been devoted to explore methods of prevention including the use of antiviral mouthwashes. This study aimed to investigate the effects of Povidone Iodine (PVP-I) and two other disinfecting solutions on the mechanical properties of orthodontic elastomeric ligatures. MATERIALS AND METHODS: In this study, 130 elastomeric ligatures in five groups (three test groups and two control groups) were examined in laboratory conditions for a period of 28 days. In the control group, specimens were kept dry in a dark environment while all other ligatures were stored in artificial saliva. Elastomeric ligatures were immersed into PVP-I solution (1%) Chlorhexidine (0.02%), and hydrogen peroxide (5%) for one minute each day in three time intervals of one day, 7 days and 28 days. Next, the maximum tensile strength of elastomeric ligatures was tested by a universal testing machine (CN 1174, Germany). RESULTS: The results showed that the tensile strength of elastomeric ligatures was significantly decreased in all three test groups after 28 days (p-value<0.05). However, the difference between groups was not statistically significant. Between-subject ANOVA test showed that there were significant correlations between the time of exposure and type of disinfecting solutions. CONCLUSIONS: PVP-I has comparable effects on elastomeric ligatures as artificial saliva, chlorhexidine, and hydrogen peroxide.

Thermoplastic mung bean starch/natural rubber/sericin blends for improved oil resistance.

Oil resistant thermoplastic elastomers (TPE) were prepared using mung bean thermoplastic starch (MTPS) blending with rubbers and sericin. Sericin was incorporated into MTPS as a compatibilizer. MTPS with sericin (MTPSS) was blended with natural rubber (NR) and epoxidized NR (ENR). Sericin at 5% improved the tensile strength (10 MPa), elastic recovery (52%) and morphology of the MTPSS/ENR blend. The mechanical properties, elastic recovery and morphology of the MTPSS5/NR blend were improved by the addition of ENR. The MTPSS/ENR showed palm (28%) and motor oils (8%) swelling resistance because of the hydrophilicity of MTPS and high polarity of ENR. The MTPSS/ENR/NR showed gasoline swelling resistance (104%) because of the hydrophilicity of MTPS and low polarity of NR. FTIR confirmed a reaction between the -NH groups of sericin and the epoxy groups of ENR. This reaction improved the compatibility, mechanical properties, elastic recovery, morphology and oils swelling resistance of the blends.

Development and Characterization of Novel Composite Films Based on Soy Protein Isolate and Oilseed Flours.

The possibility of using oilseed flours as a waste source for film-forming materials with a combination of soy protein isolate in preparation of edible films was evaluated. Physical, mechanical and barrier properties were determined as a function of the oilseed type: hemp, evening primrose, flax, pumpkin, sesame and sunflower. It was observed that the addition of oilseed flours increased the refraction and thus the opacity of the obtained films from 1.27 to 9.57 A mm-1. Depending on the type of flours used, the edible films took on various colors. Lightness (L*) was lowest for the evening primrose film (L* = 34.91) and highest for the soy protein film (L* = 91.84). Parameter a* was lowest for the sunflower film (a* = -5.13) and highest for the flax film (a* = 13.62). Edible films made of pumpkin seed flour had the highest value of the b* color parameter (b* = 34.40), while films made of evening primrose flour had the lowest value (b* = 1.35). All analyzed films had relatively low mechanical resistance, with tensile strength from 0.60 to 3.09 MPa. Films made of flour containing the highest amount of protein, pumpkin and sesame, had the highest water vapor permeability, 2.41 and 2.70 × 10-9 g·m-1 s-1 Pa-1, respectively. All the edible films obtained had high water swelling values from 131.10 to 362.16%, and the microstructure of the films changed after adding the flour, from homogeneous and smooth to rough. All blended soy protein isolate-oilseed flour films showed lower thermal stability which was better observed at the first and second stages of thermogravimetric analysis when degradation occurred at lower temperatures. The oilseed flours blended with soy protein isolate show the possibility of using them in the development of biodegradable films which can find practical application in the food industry.

Functional polysaccharide-based film prepared from chitosan and ß-acids: Structural, physicochemical, and bioactive properties.

ß-Acids are natural antibacterial and antioxidant ingredients, obtained from supercritical CO2 hop extract. In this study, ß-acids/chitosan complex films were prepared using the casting method. Complex films were characterized using scanning electron microscopy (SEM), atomic force microscope (AFM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction analysis (XRD). Structure analysis revealed that ß-acids can be successfully combined with the chitosan matrix. Mechanical tests demonstrated that the tensile strength of the films showed a significant upward trend (1.9 MPa to 9.6 MPa) with increase in ß-acids content (0.1%-0.3%). Interestingly, the chitosan-based films showed excellent UV barrier capability below 400 nm. The release of ß-acids from the film followed Fickian diffusion (n < 0.45). In addition, the complex films inhibited the growth of five food-borne pathogens (Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Salmonella enteritidis and Listeria monocytogenes). This study highlights the promising nature of composite film as a desirable alternative for active packaging.

Tailoring the biodegradability of polylactic acid (PLA) based films and ramie- PLA green composites by using selective additives.

This study explores the effect of plasticisers (lotader AX8900, polyethylene glycol and triethyl citrate) on biodegradability of polylactic acid (PLA) and its composites with halloysite nanotubes and ramie fabric by soil burial method. Changes in surface morphology and mechanical properties were evaluated to quantify the degradation behaviour of all samples. The results showed that the relative loss in tensile strength of ramie-PLA composites was more than that of neat PLA or plasticised PLA films. Also, ramie-PLA composite, where ramie fabric was treated with diammonium orthophosphate, had degraded entirely after 60 days of soil burial. It was also confirmed by Fourier transform infrared spectroscopy that the chemical structures of neat PLA and plasticised PLA films changed after the soil burial test. The use of these additives not only reduces the brittleness of PLA but also accelerates the biodegradation rate of PLA. Thus, PLA, along with additives, can help in reduction of carbon footprint and other environmental issues customarily associated with petro based polymers. Therefore, the finding supports the notion of PLA usage as a viable alternative to fossil fuel-based materials.

Poly(Vinyl Alcohol) Cryogel Membranes Loaded with Resveratrol as Potential Active Wound Dressings.

Hydrogel wound dressings are highly effective in the therapy of wounds. Yet, most of them do not contain any active ingredient that could accelerate healing. The aim of this study was to prepare hydrophilic active dressings loaded with an anti-inflammatory compound - trans-resveratrol (RSV) of hydrophobic properties. A special attention was paid to select such a technological strategy that could both reduce the risk of irritation at the application site and ensure the homogeneity of the final hydrogel. RSV dissolved in Labrasol was combined with an aqueous sol of poly(vinyl) alcohol (PVA), containing propylene glycol (PG) as a plasticizer. This sol was transformed into a gel under six consecutive cycles of freezing (-80 °C) and thawing (RT). White, uniform and elastic membranes were successfully produced. Their critical features, namely microstructure, mechanical properties, water uptake and RSV release were studied using SEM, DSC, MRI, texture analyser and Franz-diffusion cells. The cryogels made of 8 % of PVA showed optimal tensile strength (0.22 MPa) and elasticity (0.082 MPa). The application of MRI enabled to elucidate mass transport related phenomena in this complex system at the molecular (detection of PG, confinement effects related to pore size) as well as at the macro level (swelling). The controlled release of RSV from membranes was observed for 48 h with mean dissolution time of 18 h and dissolution efficiency of 35 %. All in all, these cryogels could be considered as a promising new active wound dressings.

Influences of Molecular Weights on Physicochemical and Biological Properties of Collagen-Alginate Scaffolds.

For tissue engineering applications, biodegradable scaffolds containing high molecular weights (MW) of collagen and sodium alginate have been developed and characterized. However, the properties of low MW collagen-based scaffolds have not been studied in previous research. This work examined the distinctive properties of low MW collagen-based scaffolds with alginate unmodified and modified by subcritical water. Besides, we developed a facile method to cross-link water-soluble scaffolds using glutaraldehyde in an aqueous ethanol solution. The prepared cross-linked scaffolds showed good structural properties with high porosity (~93%) and high cross-linking degree (50-60%). Compared with collagen (6000 Da)-based scaffolds, collagen (25,000 Da)-based scaffolds exhibited higher stability against collagenase degradation and lower weight loss in phosphate buffer pH 7.4. Collagen (25,000 Da)-based scaffolds with modified alginate tended to improve antioxidant capacity compared with scaffolds containing unmodified alginate. Interestingly, in vitro coagulant activity assay demonstrated that collagen (25,000 Da)-based scaffolds with modified alginate (C25-A63 and C25-A21) significantly reduced the clotting time of human plasma compared with scaffolds consisting of unmodified alginate. Although some further investigations need to be done, collagen (25,000 Da)-based scaffolds with modified alginate should be considered as a potential candidate for tissue engineering applications.

Impact on Mechanical Properties of 10 versus 20 Minute Treatment of Human Pericardium with Glutaraldehyde in OZAKI Procedure.

PURPOSE: The aim of this study was to analyze the effects of 10-minute (standard term) versus 20-minute treatment with glutaraldehyde (GA) on mechanical stability and physical strength of human pericardium in the setting of the OZAKI procedure. METHODS: Leftover pericardium (6 patients) was bisected directly after the operation, and one-half was further fixed for 10 additional minutes. Uniaxial tensile tests were performed and ultimate tensile strength (UTS), ultimate tensile strain (uts), and collagen elastic modulus were evaluated. RESULTS: Both treatments resulted in similar values of uniaxial stretching-generated elongations at rupture (10 minutes 25 ± 7 % vs. 20 minutes: 22 ± 5 %; p = 0.05), UTS (5.16 ± 2 MPa vs. 6.54 ± 3 MPa; p = 0.59), and collagen fiber stiffness (elastic modulus: 31.80 ± 15.05 MPa vs. 37.35 ± 15.78 MPa; p = 0.25). CONCLUSION: Prolongation of the fixation time of autologous pericardium has no significant effect on its mechanical stability; thus, extending the intraoperative treatment cannot be recommended.

Preparation of formyl cellulose and its enhancement effect on the mechanical and barrier properties of polylactic acid films.

Cellulose was modified by formic acid to prepare formyl cellulose (FC). The amount of formyl groups in FC was adjusted by controlling the reaction time, reaction temperature, and formic acid concentration. Then, FC was used to reinforce polylactic acid (PLA) films prepared by solution casting. Scanning electron microscopy (SEM) shows that long rod-like cellulose particles were broken into short rods after formylation and the introduction of FC made PLA surface rougher. The mechanical properties of PLA/FC films were improved by the inclusion of FC. Compared to pure PLA film, the PLA/FC composite film with 1 wt% FC (containing 15.79% formyl groups) showed a 48.59% increase in tensile strength and a 346% increase in Young's modulus. The addition of FC also resulted in better water barrier properties. The moisture absorption capacity and water vapor permeability were 40.56% and 51.43% lower than those of the pure-PLA film. The enhancement in properties for PLA/FC composites could be ascribed to the improved compatibility between PLA and cellulose with the introduction of hydrophobic formate groups. The PLA/FC composite films developed in this work could be highly potential for food packaging.

Super flexible, fatigue resistant, self-healing PVA/xylan/borax hydrogel with dual-crosslinked network.

The high mechanical strength and self-healing properties of hydrogels are the focus of tissue engineering and biomedical research. Furthermore, the incompatibility between hydrogel toughness and self-healing has not been resolved. It is noteworthy that the double network (DN) hydrogels show great promise as a viable method for producing self-healing hydrogels with the above properties. The Xylan/PVA/Borax DN hydrogel was prepared by the one-pot method, shows various excellent performances, including strong strength (ca. 81 kPa), high toughness (ca.1652.42 kJ/m3), good self-recovery (ca. 79% recovery), and excellent self-healing properties (self-healing efficiency reached to 85.8% for 30 s). This study proposes a strategy to design high strength, high toughness, large extensibility, and self-healing properties hydrogels based on xylan.

Development of Composition and Technologies of Dental Film with Ketorolac Trometamine.

The report presents the results of the development of dental films with ketorolac trometamine based on the natural biodegradable polymers from the groups of sodium alginates and xanthan gums in combination with lightly crosslinked acrylic polymer carbopol. Physicochemical properties, such as moisture, mucoadhesion, thickness, tensile strength, disintegration in phosphate buffer were determined in obtained samples of this dosage form. A comparison of physicochemical properties of experimental samples and commercial model of dental film has allowed establishing the perspective composition of complex matrix of films with ketorolac trometamine for use in dentistry.

Biomechanical comparison of tigecycline loaded bone cement with vancomycin and daptomycin loaded bone cements.

OBJECTIVE: The objectives of this study were "1" to analyze the compressive and tensile mechanical strength characteristics of tigecycline loaded bone cement and "2" to compare them with those of vancomycin and daptomycin loaded bone cements which are used in prosthetic joint infections complicated with resistant microorganisms. METHODS: In this study, three experimental groups, which consisted of vancomycin (subgroups containing 1 g, 2 g, and 3 g vancomycin), daptomycin (subgroups containing 0.5 g, 1 g, and 1.5 g daptomycin), and tigecycline (subgroups containing 50 mg, 100 mg, and 150 mg tigecycline) and one control group without antibiotics were used. Using a standardized protocol, all antibiotic loaded bone cements were prepared. For each antibiotic group, including the control group, 10 samples were tested. All samples were biomechanically tested in terms of compressive strength and tensile strength. RESULTS: Compression tests showed that all determined antibiotic concentrations resulted in a significant decrease when compared with the control group (p<0.0011). Vancomycin and daptomycin study groups demonstrated lower tensile strength than the control group (p<0.0011). However, comparison of tensile values of tigecycline study groups with the control group revealed no significant difference (p>0.0011). In addition, all statistically significant results from between groups comparisons revealed higher tensile and compressive mechanical strength values for the tigecycline groups (p<0.0011). CONCLUSION: Evidence from this study has demonstrated that tigecycline loaded bone cement may have no mechanical disadvantage compared with vancomycin and daptomycin loaded bone cements in terms of mechanical strength when used at defined concentrations.

3D printing of an integrated triphasic MBG-alginate scaffold with enhanced interface bonding for hard tissue applications.

Osteochondral defects affect both of cartilage and subchondral areas, thus it poses a significant challenge to simultaneously regenerate two parts in orthopedics. Tissue engineering strategy is currently regarded as the most promising way to repair osteochondral defects. This study focuses on developing a multilayered scaffold with enhanced interface bonding through 3D printing. One-shot printing process enables control over material composition, pore structure, and size in each region of the scaffold, while realizes seamlessly integrated construct as well. The scaffold was designed to be triphasic: a porous bone layer composed of alginate sodium (SA) and mesoporous bioactive glasses (MBG), an intermediate dense layer also composed of SA and MBG and a cartilaginous layer composed of SA. The mechanical strength including the interface adhesion strength between layers were characterized. The results indicated that SA crosslinking after 3D printing anchored different materials together and integrated all regions. Additional scaffold soaking in simulated body fluid (SBF) and cell culture medium induced apatite deposition and had weakened the compressive and tensile strengths, while no layer dislocation or delamination occurred.

Bioinspired tissue-compliant hydrogels with multifunctions for synergistic surgery-photothermal therapy.

Operation therapy is a common treatment for many cancers, but malignant tumors likely recur and metastasize after surgery, resulting in treatment failure. In this study, we aimed at synthesizing a multifunctional hydrogel patch that features multifunctions for synergistic surgery-photothermal therapy. Our polydopamine nanoparticle (PDA NP)-crosslinked poly(acrylamide-co-N-(3-aminopropyl)methacrylamide) hydrogels undergo several dynamic interactions (e.g., hydrogen bonds, π-π interactions, and imine bonds), which confer high stretchability (∼3430%) and adhesive strength to porcine skin (∼75 kPa) that mimics soft wound tissues. Furthermore, PDA NP incorporation into the hydrogel matrix endows it with photothermal responsivity under 808 nm irradiation. As a proof of concept, our hydrogel system was used to ablate residual tumors in 4T1 tumor-bearing mice models after surgery via photothermal therapy. We find that synergistic operation-photothermal therapy effectively eradicates solid tumors and prevents cancer recurrence in mice. We envision that our work provides an effective synergistic strategy for cancer treatment and offers great potential for clinical applications.

Development of biobased multilayer films with improved compatibility between polylactic acid-chitosan as a function of transition coating of SiOx.

A SiOx coating prepared via plasma-enhanced chemical vapor deposition (PECVD) technique was used as a transition layer between polylactic acid (PLA) and chitosan (CS) to form a three-layer composite film of PLA/SiOx/CS. The effect of oxygen plasma irradiation time (0 s, 30s and 60s) on SiOx surface and PLA-CS interface was examined based on the contact angle, pull-off test and scanning electron microscope (SEM). The mechanical, barrier and antibacterial properties of PLA/SiOx/CS films were also investigated. The results showed that oxygen plasma irradiation improved the hydrophilicity of the SiOx surface and the adhesive strength between SiOx-CS of PLA/SiOx/CS films in a time-dependent manner. SEM examination revealed a gap between PLA/CS layers, but the interfacial separation among layers in PLA/SiOx/CS films disappeared as the transition layer of SiOx and oxygen plasma irradiation (60s) intensified. Notably, the oxygen barrier property and antibacterial activity of PLA/SiOx/CS films were dramatically enhanced. Additionally, moisture resistance was slightly decreased following the incorporation of the CS coating compared with the PLA film. The tensile strength of the composite film also increased with the number of layers, while elongation at break decreased. The prepared PLA/SiOx/CS films with multifunction are promising applied in food packaging as biobased materials.

Characterization on chemical and mechanical properties of silane treated fish tail palm fibres.

A novel cellulosic fibre was extracted from the peduncle portion of the fish tail palm tree and the extracted fish tail palm fibre was treated with different concentrations (1%, 5%, and 9%) of silane solution. The characteristic analysis on chemical, functional, mechanical and surface property of the extracted fish tail palm fibres were investigated through chemical composition analysis, Fourier Transform InfraRed spectroscopy (FT-IR), single fibre tensile test, and Scanning Electron Microscopy (SEM). Chemical analysis results indicate that silane treatment improved the cellulose content of the fish tail palm fibre. The highest cellulose content of 72.51% was observed in the 9% silane treated fish tail palm fibre. Also, it improved crystallinity index value of 62.5% for 5% silane treated fibre, which is confirmed through the X-ray diffraction analysis. FT-IR result indicates the removal of hemicellulose at characteristic wavelength of 1745 cm-1 for 5% silane treated fish tail palm fibre. Tensile property of the silane treated fish tail palm fibre (1, 5, and 9%) shows an increased tensile strength of 7.3%, 12%, and 6.6% as compared to raw fish tail palm fibre. Moreover, this type of novel natural fibres can reduce the cost while offering competent performance during the polymer-based product development.

Effect of matrix metalloproteinase inhibitors on microtensile bond strength of dental composite restorations to dentin in use of an etch-and-rinse adhesive system.

AIM: This study assesses the effect of matrix metalloproteinases on microtensile bond strength (µTBS) of an etch-and-rinse adhesive system. METHODS: This in vitro study evaluated 88 extracted premolars. The teeth were sectioned to expose dentin and were then randomly divided into four groups (n = 22). In group 1 (control), dentin surface was etched, and Adper Single Bond 2 was applied. In groups 2-4, dentin surface was etched and chlorhexidine (CHX), 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC), and dimethyl sulfoxide (DMSO) were applied on the surfaces, respectively, and blotted dry. Next, Adper Single Bond 2 was applied and all teeth were built up with Z350 composite. In each group, half the samples immediately and the other half after 10,000 thermal cycles underwent µTBS test. Data were analyzed using ANOVA and Tukey's test (α = .05). RESULTS: In thermocycled samples, maximum µTBS was noted in CHX group followed by DMSO, EDC, and control group (p < .001). The thermocycled µTBS of composite to dentin was significantly higher in CHX group compared with EDC, DMSO, and control groups (p < .001) but was not significantly different in EDC and DMSO groups (p = .498). CONCLUSION: The thermocycled µTBS obtained by the application of CHX, EDC, and DMSO was significantly higher compared with the value to the control group.

Effect of grapefruit seed extract ratios on functional properties of corn starch-chitosan bionanocomposite films for active packaging.

The objective of this research was to investigate the effect of different ratios of grapefruit seed extract (GFSE) on functional properties of bionanocomposite (BNC) films prepared with corn starch (CS) incorporated with chitosan (CH)-nanoclay. Experimental results exhibited that the addition of GFSE properly dispersed with CS combined with CH bionanocomposite films. The presence of GFSE from 0 to 1.5% v/v exhibited increase in crystallinity and TS while decease in EB, FS and WVP. Furthermore, an addition of 2%v/v GFSE revealed decrease in its physical properties. When bread samples were packed, synthetic plastic exhibited the proliferation of fungal growth in 6 days, whereas CS/CH/1.5% v/v GFSE bionanocomposite film exhibited the same for at least 20 days. This study presents that CS/CH/1.5% v/v GFSE nanoclay film could potentially be useful for novel eco-friendly active packaging for confectionary industries to extend the shelf life to maintain its quality and safety of food products.