Nanohybrid Composite Research Articles

Effect of the application of a hydrogen peroxide home bleaching agent on the cytotoxicity of different CAD-CAM restorative materials.

The information regarding the cytotoxicity of ceramic and resin-matrix ceramic materials subjected to over-the-counter bleaching agents is limited in the literature. The aim of the present study was to investigate the cytotoxic effects of lithium disilicate ceramic (LDC), resin nano-ceramic (RNC) and nano-hybrid composite (NHC) computer-aided design/ computer-aided manufacturing (CAD-CAM) block materials subjected to a home bleaching agent and artificial saliva. A total of 432 specimens were prepared from 3 different CAD-CAM materials. Each material group was divided into 4 groups according to the storage medium (phosphate-buffered saline (PBS) or artificial saliva), and whether the specimens were subjected to a bleaching agent or not. For the bleached groups, hydrogen peroxide (10%) was applied to the specimens for 30 min/day for 15 days, and the specimens were immersed in PBS or saliva after bleaching. The viability of epithelial cells was detected using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay at the end of the 5th, 10th and 15th day of the study. The data was statistically analyzed. Regardless of the storage medium and the time period, all restorative materials decreased the viability of cells. The highest cytotoxicity levels were determined on the 15th day of the study. The application of a bleaching agent increased the cytotoxicity of the LDC specimens stored in artificial saliva. The RNC material stored in PBS demonstrated significantly higher cell viability than the LDC and NHC groups. The LDC and RNC specimens stored in artificial saliva did not show any significant difference in cytotoxicity. When the materials were subjected to bleaching, NHC demonstrated the highest cytotoxicity during all periods. No significant difference was found between the LDC and RNC specimens subjected to both artificial saliva and bleaching in terms of cytotoxicity. The type of restorative material, the immersion medium, the application of a bleaching agent, and the application period affected the cytotoxicity of the materials. Over-the-counter home bleaching agents may induce cellular cytotoxicity due to the existing restorations, and patients should be informed about this potential biological response.

Wear behavior of ceramic, composite, and ceramic/composite interfaces

Objective. This study has aimed to evaluate the effects of toothbrushing on the wear behavior of two composites, three ceramic materials, and ceramic/composite interfaces. Material and Methods. Nanofilled (Filtek Ultimate), and nanohybrid composites (Spectra ST HV) were used for the repair of a hybrid ceramic (Vita Enamic), resin nanoceramic (Katana Avencia), and zirconia block (Katana Zirconia). Composites, ceramics, and ceramic/composite interfaces were examined before and after a period of one-month and one-year of toothbrush abrasion testing using non-contact optical profilometry and scanning electron microscopy (SEM). Data were analyzed by two-way ANOVA and Bonferroni correction. The statistical significance level was set at p < 0.05. Results. No difference was found between the surface roughness of the Vita Enamic, Katana Avencia, Filtek Ultimate, and Spectra surfaces after one month and one year of toothbrushing. Sa values in Katana Zirconia material were found to be significantly lower than those in the control group after one year of brushing. The surface roughness of the repair interfaces formed by repairing hybrid ceramic and resin nanoceramic CAD/CAM materials with nanofilled and nanohybrid composite materials was found to be similar after different brushing times. Conclusion. Vita Enamic, Katana Avencia, Filtek Ultimate, and Spectra materials can be preferred in clinical repair applications, since they exhibit similar wear behavior after brushing at different times. For the zirconia material, the repair interface had similar surface roughness as the ceramic and composite surfaces after one year of brushing. Periodic recalls and re-polishing may thus be necessary when these products are used clinically.

A hybrid composite of Polypyrole/carboxymethyl cellulose/MWCNT fiber with antimicrobial properties and Sb3+ determination on a glassy carbon electrode

ABSTRACT In order to prepare fiber-type nanohybrid composites for electrochemical and antimicrobial applications, polypyrrole was combined with carboxymethylcellulose and multiwalled carbon nanotubes (PPy/CMC/MWCNTS). These composite materials were synthesized using ultrasonication and in situ polymerization. By using analytical methods, the structure and morphology of the synthesized nanohybrid composite material were confirmed. Slurry of fiber-type PPY/CMC/MWCNT composites synthesized in ethanol was deposited as a thin-uniform layer with conductive nafion (5% ethanolic solution of nafion) binder. Based on electrochemical measurements in a phosphate buffer medium, Sb3+ ions have linear responses between 0.1 nM and 0.01 mM, which is known as linear dynamic range (LDR). A sensor’s sensitivity (22.4304 µAµM−1cm−2) is calculated using the LDR slope by considering the GCE surface area (0.0316 cm2). A signal-to-noise ratio of 3 is used to estimate the lower limit of detection which is equal to 96.82 ± 4.84 pM. Moreover, the antibacterial activity of the obtained polypyrrole/carboxymethylcellulose/MWCNT composite has also been evaluated “against Gram-positive bacteria B. subtilis along with S. aureus, as well as Gram-negative bacteria, P. aeruginosa along with Escherichia coli by utilizing” autoclave of agar media. In electrochemical analysis, the proposed Sb3+ cationic sensor exhibits appreciable reproducibility, response time, stability, and outstanding outcome in analysis of real samples. In the field of metal ion sensor, this reliable method might be prospective in the recent future.

Effect of Different Bleaching Methods on Monomer Release from Aged Microhybrid and Nanohybrid Resin Composites.

Recently, the application of laser-assisted bleaching has increased in dental practice. This method might affect the physical and chemical properties of resin composite and its monomer release. This study aimed to evaluate the effect of in-office, at-home, and laser-assisted bleaching on the monomer release (bisphenol A diglycidyl dimethacrylate (BisGMA), triethylene glycol dimethacrylate (TEGDMA), and urethane dimethacrylate (UDMA)) from aged nanohybrid (Grandio, Voco) and microhybrid (Clearfil AP-X Esthetics, Kuraray) resin composites. Thirty-two samples of each composite were prepared. The samples underwent aging procedure with UV light at 65°C for 100 hr. The samples were divided into 4 groups: OB: conventional in-office bleaching with Opalescence Boost PF 40% gel; HB: home bleaching with Opalescence PF 15% gel; LB: bleaching with JW Power bleaching gel followed by diode laser application; and C: control group without bleaching. Then, the samples were immersed in a solution containing 75% ethanol + 25% distilled water. The medium was renewed after 8, 16, 24 hr, and 7 days and was analyzed using high-performance liquid chromatography method to evaluate the monomer release. The data were analyzed using Two-way ANOVA and Post hoc Tukey test. The bleaching method had no effect on TEGDMA and BisGMA release in both composites while it affected UDMA release in nanohybrid composite; UDMA release was significantly higher in LB compared to control and also higher in OB and LB compared to HB. No difference was observed in the microhybrid composite in this regard. Laser-assisted bleaching did not affect monomer release from microhybrid composite while it increased UDMA release from nanohybrid composite. The bleaching method had no effect on TEGDMA and BisGMA release.

Peroxide-Free Bleaching Gel: Effect on the Surface and Mechanical Properties of Nano- and Micro-Hybrid Restorative Composite Materials

This laboratory investigation was designed to test the influence of a novel bleaching formulation based on phthalimidoperoxycaproic acid (PAP) with additives on the surface and mechanical properties of nano- and micro-hybrid restorative composites. Twenty-four bar-shaped and twelve disk-shaped samples from each restorative composite were prepared. The samples from each restorative composite were randomly divided into two groups according to the treatment, i.e., experimental and control. The treated groups went through the bleaching process: by Opalescence Regular or novel PAP+-containing gel (HiSmile™). The treated group underwent a bleaching process for seven consecutive days (a 10-min session of bleaching application every day) before the properties were tested. A paired sample t-test was performed to compare the results between the experimental and the control groups. The level of significance was set at 0.05. The surface roughness of the nanohybrid composite using Opalescence Regular (p &lt; 0.05) was significant. Additionally, a significant difference in nanohardness and elastic modulus between the experimental and the control groups of the microhybrid composite using Opalescence Regular was observed: p = 0.041 and p = 0.023, respectively. While a marked difference in flexural strength was observed in the experimental and control groups using Opalescence Regular, Hismile™ bleaching gel caused a diminutive and insignificant reduction in tested properties (p &gt; 0.05). It was found that Opalescence Regular bleaching gel affects the surface and bulk properties of restorative composite materials, whereas the novel PAP+ formulation has no deleterious effect on either nano- or micro-hybrid restorative composites.

Effect of Type of Resin Composite Material on Porosity, Interfacial Gaps and Microhardness of Small Class I Restorations.

This study aimed to compare the best restorative approach for the conservative class I cavity by comparing flowable and nanohybrid composites versus the placement technique regarding surface microhardness, porosity, and presence of interface gaps. Forty human molars were divided into four groups (n = 10). Standardized class I cavities were prepared and restored using one of the following materials: Group I - Flowable composite placed by incremental technique; group II - Flowable composite placed in one increment; group III - Nanohybrid composite placed by incremental technique; and group IV - Nano-hybrid composite placed in one increment. After finishing and polishing, specimens were sectioned into two halves. One section was chosen randomly for the Vickers microhardness (HV) evaluation and the other section was used for the assessment of porosities and interfacial adaptation (IA). The surface microhardness range was 28.5-76.2 (p < 0.05), mean pulpal microhardness range was 27.6-74.4 (p < 0.05). Flowable composites had lower HV than conventional counterparts. The mean pulpal HV of all materials exceeded 80% of occlusal HV. Restorative approaches did not statistically differ in porosities. However, IA percentages were higher in flowable materials compared to nanocomposites. Flowable resin composite materials have lower microhardness than Nanohybrid composites. In small class I cavities, the number of porosities was similar between the different placement techniques and the interfacial gaps were highest in the flowable composites. The use of nanohybrid resin composite to restore class I cavities will result in better hardness and less interfacial gaps compared to flowable composites.

Clinical Outcome of Class I and II Restorations with and without an Intermediary Layer of a Flowable Composite after 24 Months: A Prospective, Randomized, Split-Mouth-Designed, Controlled and Single-Blinded Clinical Trial

The aim of this clinical study was to evaluate the impact of an additional use of a flowable composite on the clinical success of Class I and II composite restorations. Furthermore, different clinical criteria were recorded to determine if the combination with a flowable material shows significant advantages compared to the composite material alone. In 50 patients, one cavity was solely filled with a nano-hybrid composite (control group) and the second cavity in combination with an additional layer of flowable composite (test group) using a universal adhesive system in the self-etch modus. Clinical assessments were performed according to the modified criteria proposed by USPHS/Ryge. After 24 months, 47 patients were examined resulting in a recall rate of 94%. The cumulative survival rate for all restorations after 24 months was 96.8%. Three restorations (3.2%) failed due to the loss of vitality. All failed restorations were located in the test group (6.4%), and none in the control group (0%). This resulted in a cumulative success rate in the control group of 100% and 93.6% in the test group, showing a significantly different annual failure rate (AFR) of 0% and 3.2%, respectively (p &lt; 0.05; Mann–Whitney U-test). Beside the differences regarding the tooth vitality, success rate, and AFR, no significant influence of the flowable composite on the different evaluated clinical parameters could be detected. Therefore, the application of an additional layer of the flowable composite might have neither a positive nor a negative effect on composite restorations in clinical practice.

Impact of graphene nano particles on tribological behaviour of carbon fibre reinforced composites

ABSTRACT The purpose of this investigation is to see how varying percentages of Graphene Nanoplatelets (GNP) affect the wear behaviour of carbon fibre reinforced epoxy (CFRE) composite. The hybrid nano composites were developed using hand layup process followed by compression moulding. Furthermore, the impact of operational parameters such as load and abrading distance against SiC paper of 220 grit size at a rotational speed of 200 rpm was investigated. It was found that incorporating a considerable amount (up to 0.5 wt. %) of GNP significantly improved the wear performance of CFRE composites. There is increase in wear loss again for 0.75 and 1.0 wt. % GNP. The morphology of developed nano hybrid composites were linked to data patterns on wear volume and specific wear rates. GNP addition up to 0.5 wt. % strengthened the fibre-matrix interface, preventing simple fibre pull-out from matrix/fillers and enabling increased wear resistance, according to worn surface characteristics investigation.

Effect of Hydrothermal Factors on the Microhardness of Bulk-Fill and Nanohybrid Composites

This study evaluates the effect of aging in artificial saliva and thermal shocks on the microhardness of the bulk-fill composite compared to the nanohybrid composite. Two commercial composites, Filtek Z550 (3M ESPE) (Z550) and Filtek Bulk-Fill (3M ESPE) (B-F), were tested. The samples were exposed to artificial saliva (AS) for one month (control group). Then, 50% of the samples from each composite were subjected to thermal cycling (temperature range: 5-55 °C, cycle time: 30 s, number of cycles: 10,000) and another 50% were put back into the laboratory incubator for another 25 months of aging in artificial saliva. The samples' microhardness was measured using the Knoop method after each stage of conditioning (after 1 month, after 10,000 thermocycles, after another 25 months of aging). The two composites in the control group differed considerably in hardness (HK = 89 for Z550, HK = 61 for B-F). After thermocycling, the microhardness decrease was for Z550 approximately 22-24% and for B-F approximately 12-15%. Hardness after 26 months of aging decreased for Z550 (approximately 3-5%) and B-F (15-17%). B-F had a significantly lower initial hardness than Z550, but it showed an approximately 10% lower relative reduction in hardness.

Corrigendum to ‘Influence of tool rotation speeds on mechanical and morphological properties of friction stir processed nano hybrid composite of MWCNT-Graphene-AZ31 magnesium’ [Journal of Magnesium and Alloys 7 (2019) 487–500

Corrigendum to ‘Influence of tool rotation speeds on mechanical and morphological properties of friction stir processed nano hybrid composite of MWCNT-Graphene-AZ31 magnesium’ [Journal of Magnesium and Alloys 7 (2019) 487–500

Polymeric graphitic carbon nitride layers decorated with erbium oxide and enhanced photocatalytic performance under visible light irradiation.

Developing and implementing visible light active organic-inorganic hybrid semiconductor nanomaterials with enhanced photocatalytic properties find newer environmental and energy treatment capabilities. Here, we are reporting polymeric g-C3N4 layers coated with different propositions of erbium oxide nanoparticles, characterized using XPS, UV-Vis-DRS, FT-IR, HR-TEM, FE-SEM, elemental mapping, XRD and surface area techniques and its photocatalytic activities were evaluated under visible light irradiations. The hybrid nanocomposite materials possess better crystalline nature and erbium oxide particles were on the surface of polymeric g-C3N4. The surface area and bandgap energy of the polymeric g-C3N4-erbium oxide (5 wt%) nanohybrid composite were 99.9 m2/g and 2.52eV. The photocatalytic activities as prepared nanohybrid composites were assessed for the oxidation of orange G dye molecules in the presence of visible light and were highly active in a broader range of pH with the presence of various inorganic anions. The rate of photocatalytic oxidation of dye molecules varied from 4.79 × 10-4 to 1.77 × 10-4min-1 for the initial concentration of 5 to 20ppm and retained its activities above 95% up to three cycles of reusability. Hence, the organic-inorganic novel catalytic nanohybrid composite may find more comprehensive applications in the area of environmental and energy applications.

Synergistic effect in g-C3N4/CuO nanohybrid structures as efficient electrode material for supercapacitor applications

A facile thermal decomposition and hydrothermal techniques were used to fabricate g-C3N4/CuO nanohybrid electrode material. The pure g-C3N4, CuO and g-C3N4/CuO nanohybrid composites were confirmed by powder X-ray diffraction (XRD), high-resolution scanning electron microscopy (HRSEM) and Fourier-transform infrared spectroscopy (FTIR). The g-C3N4/CuO electrode material exhibited a specific capacitance of 98F/g which is substantially higher than those using bare CuO (40F/g) and bare g-C3N4 electrodes (62F/g). Cycle-life data for over 2500 cycles reflect 19 % capacitance degradation for g-C3N4/CuO nanohybrid material. The energy density given by g-C3N4/CuO, CuO and g-C3N4 devices is 14.8 W h kg−1, 5 W h kg−1 and 6.3 W h kg−1 respectively. The enhanced electrochemical performance of the nanohybrid material is ascribed to synergistic effect and pseudo capacitive nature of the metal oxide nanoparticles incorporated in the g-C3N4 matrix.

Comparative Evaluation of Colour Stability and Surface Roughness of Nanohybrid Composite Resins in Mouth Rinse and Colouring Beverages.

Objectives An ideal restorative material should be capable of supplanting the biological, functional, and aesthetic qualities of a healthy tooth structure. There has always been a search for optimal and aesthetically pleasing restorative materials. This study aims to evaluate the surface roughness and colour stability of three nanohybrid composite resins post-exposure to mouth rinse and colouring beverages. Methods One hundred and twenty specimens of dimension 10 mm x 8 mm x 1 mm were randomly allocated into three equal-sized groups and fabricated using three different nanohybrid composites (Group A: Filtek Z250 XT, Group B: Tetric N-Ceram, and Group C: Solare Sculpt). Sixty samples, comprising 20 from each group, were examined for colour stability and 60 for surface roughness after exposure to chlorhexidine and coffee. Baseline and post-exposure readings of the surface roughness and colour absorbance of the specimens were obtained by atomic force microscopy and spectrophotometer, respectively. A one-way analysis of variance (ANOVA) test followed by a post hoc Tukey's test and an independent t-test were used for data analysis, considering a p-value<0.05 as significant. Results Irrespective of the composite, the surface roughness and colour change were substantially higher in the samples exposed to coffee (p-value<0.01). Filtek Z 250XT showed significantly minor changes in colour and surface roughness, followed by Solare Sculpt and Tetric N-Ceram (p-value<0.05). Conclusion Coffee caused more surface roughness and colour changes compared to chlorhexidine. Filtek 250 XTshowed minor changes in colour and surface roughness on exposure to both solutions.

The Impact of Simulated Bruxism Forces and Surface Aging Treatments on Two Dental Nano-Biocomposites-A Radiographic and Tomographic Analysis.

Background and Objectives: Nowadays, indication of composite materials for various clinical situations has increased significantly. However, in the oral environment, these biomaterials are subjected (abnormal occlusal forces, external bleaching, consumption of carbonated beverages, etc.) to changes in their functional and mechanical behavior when indicated primarily for patients with masticatory habits. The study aimed to recreate in our lab one of the most common situations nowadays-in-office activity of a young patient suffering from specific parafunctional occlusal stress (bruxism) who consumes acidic beverages and is using at-home dental bleaching. Materials and Methods: Sixty standardized class II cavities were restored with two nanohybrid biocomposite materials (Filtek Z550, 3M ESPE, and Evetric, Ivoclar Vivadent); the restored teeth were immersed in sports drinks and carbonated beverages and exposed to an at-home teeth bleaching agent. The samples were subjected to parafunctional mechanical loads using a dual-axis chewing simulator. A grading evaluation system was conducted to assess the defects of the restorations using different examination devices: a CBCT, a high-resolution digital camera, and periapical X-rays. Results: Before mechanical loading, the CBCT analysis revealed substantially fewer interfacial defects between the two resin-based composites (p > 0.05), whereas, after bruxism forces simulation, significantly more defects were identified (p < 0.05). Qualitative examination of the restorations showed more occlusal defects for the Evetric than the other nanohybrid composite. Conclusions: There were different behaviors observed regarding the studied nanocomposites when simulation of parafunctional masticatory forces was associated with aging treatments.

Surface smoothness of resin composites after polishing-A systematic review and network meta-analysis of in vitro studies.

A systematic review and network meta-analysis was performed to provide evidence for the best polishing protocol for different types of resin composites to minimize surface roughness. A search was performed in PubMed, Scopus, Web of Science, LILACS, BBO, EMBASE, and Cochrane Library on July 2, 2019 (updated in December, 2020). In vitro studies that included at least two systems for polishing resin composites and analyzed surface roughness were included. The risk of bias was evaluated. A random-effects Bayesian-mixed treatment comparison model was used to compare surface roughness in resin composites with the different types of polishers. Surface under the cumulative ranking curve (SUCRA) analysis was performed to rank the probability for the best polishing system. After removal of duplicates, title and abstract screening yielded 34 studies. Network meta-analysis was not possible for hybrid and microhybrid composites. SUCRA analysis showed that abrasive paper discs allowed greater surface smoothness for nanohybrid and nanofill composites to a probability of between 83% and 91.6%. Silicon carbide brush had a 78.2% probability of being the best system for microfill composites. The use of abrasive paper disc polishers showed a favorable result in nanofill and nanohybrid resin composites. Silicon carbide brush has a greater chance of promoting a smoother surface for microfill resin composites.

Eco-friendly fabrication of nonenzymatic electrochemical sensor based on cobalt/polymelamine/nitrogen-doped graphitic-porous carbon nanohybrid material for glucose monitoring in human blood

The design and development of eco-friendly fabrication of cost-effective electrochemical nonenzymatic biosensors with enhanced sensitivity and selectivity are one of the emerging area in nanomaterial and analytical chemistry. In this aspect, we developed a facile fabrication of tertiary nanocomposite material based on cobalt and polymelamine/nitrogen-doped graphitic porous carbon nanohybrid composite (Co-PM-NDGPC/SPE) for the application as a nonenzymatic electrochemical sensor to quantify glucose in human blood samples. Co-PM-NDGPC/SPE nanocomposite electrode fabrication was achieved using a single-step electrodeposition method under cyclic voltammetry (CV) technique under 1 M NH4Cl solution at 20 constitutive CV cycles (sweep rate 20 mV/s). Notably, the fabricated nonenzymatic electroactive nanocomposite material exhibited excellent electrocatalytic sensing towards the quantification of glucose in 0.1 M NaOH over a wide concentration range from 0.03 to 1.071 mM with a sensitive limit of detection 7.8 μM. Moreover, the Co-PM-NDGPC nanocomposite electrode with low charge transfer resistance (Rct∼81 Ω) and high ionic diffusion indicates excellent stability, reproducibility, and high sensitivity. The fabricated nanocomposite materials exhibit a commendable sensing response toward glucose molecules present in the blood serum samples recommends its usage in real-time applications.

Comparative evaluation of genotoxicity and cytotoxicity of flowable, bulk-fill flowable, and nanohybrid composites in human gingival cells using cytome assay: An in vivo study.

Biocompatibility is one of the major prerequisites for safe clinical application of materials. Resin composites release their components into oral environment following restoration which cause adverse reactions. To evaluate and compare the genotoxicity and cytotoxicity of flowable, bulk-fill flowable, and nanohybrid composites with glass ionomer cement in human gingival cells using epithelial-based cytome assay. Sixty healthy patients with noncarious cervical lesions were selected and randomly assigned to four groups (n = 15): Group A, glass ionomer cement; Group B, flowable composite; Group C, bulk-fill flowable composite; and Group D, nanohybrid composite. Class V restorations were done in each group with the respective restorative materials. Samples of epithelial cells were collected from gingiva before (control) (T1) and after 10 and 30 days (T2 and T3) postrestoration and examined for the presence of micronuclei and other nuclear anomalies. The results were subjected to statistical analysis using Friedman's test and Kruskal-Wallis test. The highest level of cytotoxicity was noted at T2 time point with a significant decline at T3 time point. Least cytotoxic damage was exhibited by Group A followed by Group D. Highest cytotoxic effect was shown by Group B followed by Group C. There was no significant level of genotoxicity induced by any of the materials tested at different time points. There is significant cytotoxicity induced by the tested composite materials which had no long-term effects and no genotoxicity was induced by any of the restorative materials tested.

Cytotoxicity and reactive oxygen species production induced by different co-monomer eluted from nanohybrid dental composites

BackgroundSafety issues for dental restorative composites are critical to material selection, but, limited information is available to dental practitioners. This study aimed to compare the chemical and biological characteristics of three nanohybrid dental composites by assessing filler particle analysis, monomer degree of conversion (DC), the composition of eluates, and cytotoxicity and reactive oxygen species (ROS) production in fibroblasts.MethodsThree nanohybrid composites (TN, Tetric N-Ceram; CX, Ceram X Sphere Tec One; and DN, DenFil NX) were used. The size distribution and morphology of the filler particles were analysed using scanning electron microscopy (n = 5). The DC was measured via micro-Raman spectroscopy (n = 5). For the component analysis, methanol eluates from the light-polymerised composites were evaluated by gas chromatography/mass spectrometry (n = 3). The eluates were prepared from the polymerised composites after 24 h in a cell culture medium. A live/dead assay (n = 9) and Water-Soluble Tetrazolium-1 assay (n = 9) were performed and compared with negative and positive controls. The ROS in composites were compared with NC. Statistical significance in differences was assessed using a t-test and ANOVA (α = 0.05).ResultsMorphological variations in different-sized fillers were observed in the composites. The DC values were not significantly different among the composites. The amounts of 2-hydroxyethyl methacrylate (HEMA) were higher in TN than DN (p = 0.0022) and triethylene glycol dimethacrylate (TEGDMA) in CX was higher than in others (p < 0.0001). The lowest cell viability was shown in CX (p < 0.0001) and the highest ROS formation was detected in TN (p < 0.0001).ConclusionsThree nanohybrid dental composites exhibited various compositions of filler sizes and resin components, resulting in different levels of cytotoxicity and ROS production. Chemical compositions of dental composites can be considered with their biological impact on safety issues in the intraoral use of dental restorative composites. CX with the highest TEGDMA showed the highest cytotoxicity induced by ROS accumulation. DN with lower TEGDMA and HEMA presented the highest cell viability.

Surface roughness of nanohybrid composite resin after exposure of basil leaf extract solution

Background: Dental caries is a chronic dental disease due to microbial metabolic activity, which causes tooth demineralization. Dental caries prevalence in Indonesia in 2018 was 45.3%. The prevalence value of dental caries can be reduced by restoring teeth and maintaining oral hygiene. One of the dental restoration materials is nanohybrid composite resin. Basil leaf extract solution (Ocimum sanctum) has the potential to be used as a mouthwash because it contains eugenol and polyphenols, which have antibacterial properties against Streptococcus mutans at concentrations of 2% and 4% to improve oral hygiene and prevent primary and secondary caries. Secondary caries occurs due to bacteria's attachment and penetration of restorative materials with a rough surface. The surface roughness of the composite increased after exposure to eugenol and polyphenols. Purpose: To determine the effect of exposure to a solution of Ocimum sanctum leaf extract concentration of 2% and 4% on the surface roughness of nanohybrid composite resin. Methods: Plant determination, phytochemical test, acidity test, immersion for five days, and surface roughness test. Results: Ocimum sanctum leaf extract contains 0.21% eugenol and 5.11% polyphenols, and the extract solution has a pH of 4.7. The mean increase in surface roughness on the top and bottom surfaces of the nanohybrid composites after exposure to 2% and 4% Ocimum sanctum leaf extract solutions was significantly different from exposure to distilled water (p&lt;0.05). Conclusion: Exposure to Ocimum sanctum leaf extract solution increased the surface roughness of nanohybrid composite resin.

Effect of single serve sachet powder drinks on color stability of a nano-hybrid composite resin

Aim: Nano-filled composite resin materials used for aesthetic purposes have better mechanical, polish ability, and color stability properties compared to other composite resin types. The aim of this in vitro study was to evaluate the effect of 5 different single serve sachet powder drinks popular among adolescents in recent years on the color change of Nano hybrid composite resin material. Material and Method: In this study, Nano hybrid composite resin (Filtek Z550) and five different types of sachet drinks (cherry flavored powdered drink [Cherry-dp], instant sachet Turkish coffee [IS-Turkish-c], instant sachet filter coffee [IS-Filter-c], instant tea [I-tea], 3-in-1 granulated coffee [3-in-1 Granulated-c] and distilled water [DW]) were used. A total of 42 2×10 mm disc-shaped samples were prepared. The prepared samples were kept in DW in an oven at 37°C for 24 hours and the initial color measurements were made with a spectrophotometer (Vita Easy Shade Advance 4.0., Germany). The samples were divided into 6 groups (n=7) to be kept in 5 colorant solutions and DW (control group). Composite samples were kept in an oven at 37°C and the solutions were changed once a week. Color change was measured before and after 1, 7, and 28 days of immersion. Shapiro Wilk test was used to check whether the data conformed to normal distribution. The variables were analyzed with one-way analysis of variance ANOVA and post-hoc Tukey test (p&amp;lt;0.05). Results: After 28 days of immersion, IS-Turkish-c, IS-Filter-c, and I-tea led to statistically significant discoloration in composite resin (p&amp;lt;0.05). In contrast, no statistically significant difference in discoloration was observed after 24 hours and 7 days of immersion (p&amp;gt;0.05). Conclusion: The results obtained in the present study showed that the Nano hybrid composite material is sensitive to discoloration by long-term use of IS-Turkish-c, IS-Filter-c, and I-tea. It was thought that Nano hybrid composite should not be preferred especially in young people with high coffee and tea consumption or necessary warnings should be given if it is to be used.