Nanohybrid Composite Materials Research Articles

Comparison of Surface Roughness of Class V Cavity Preparation using Diamond Abrasive Point and Ultrasonic Tip and Measurement of Shear Bond Strength after Restoration with Composite Resin: An In-vitro Study

Introduction: Non Carious Cervical Lesions (NCCLs) represent a prevalent dental condition characterised by the erosion of tooth structure at the cementoenamel junction without the involvement of dental caries. These lesions pose significant challenges due to their aesthetic impact, potential for dentinal hypersensitivity, plaque accumulation, pulpal complications and compromised structural integrity of the teeth. Tooth preparation traditionally uses diamond abrasive points and tungsten carbide burs for micromechanical adhesion. Newer methods, like ultrasonic tips, offer a more conservative approach, but limited research has compared their effects on bond strength, particularly in cervical cavity restorations with nanohybrid composites. Aim: To compare the surface roughness of cervical cavity preparations utilising diamond abrasive points and ultrasonic tips, and to evaluate the shear bond strength of restorations with composite resin. Materials and Methods: The present in-vitro comparative study was conducted in the Department of Conservative Dentistry and Endodontics, Guru Nanak Institute of Dental Sciences and Research, Panihati, Kolkata, West Bengal, India, from October 2023 to December 2023. The study included 52 freshly extracted maxillary 1st premolar teeth extracted for orthodontic reasons. These teeth were divided into two groups: Group-I (n=26) underwent surface preparation using a diamond abrasive point (No. 835-012, Piranha, SS White, USA), while Group-II (n=26) was prepared using an ultrasonic tip (Woodpecker G 20, Guilin Woodpecker, China). Teeth were cleaned, disinfected and stored in 0.1% thymol solution before being prepared with diamond abrasive points or ultrasonic tips, following which the specimens were restored using nanohybrid composite material (Solare X, GC Corporation, Japan). Surface roughness was assessed using a digital profilometer before the restoration, and the shear bond strength of repaired specimens was measured with a Universal Testing Machine. Statistical analysis was performed using GraphPad Prism, with independent samples t-tests applied to compare results between groups, and a significance level set at 5%. Results: Group-I exhibited greater surface roughness (6.33±2.18 μm) compared to Group-II (4.91±1.57 μm). Group-I also showed higher shear bond strength (62±13 MPa) than GroupII (59.3±19.9 MPa), though this variation was not statistically significant (p-value=0.56). Conclusion: Within the present study’s limitations, diamond abrasive points created significantly greater surface roughness compared to ultrasonic tips. However, no statistically significant variations have been observed in shear bond strength among the two methods, suggesting that ultrasonic tips may be considered as an alternative to diamond abrasive points in clinical settings, avoiding their drawbacks while achieving adequate restoration retention.

Solid particle erosion behavior of Graphene/SiC/Al2O3/TiO2 coated Kevlar/Epoxy composite materials

In light of the finding of a research-based solution for erosion with fabrication and test ceramic fillers incorporating composite material, this research used the electro-spun method to cover fibre mats with nanofiller materials such as graphene, SiC, Al2O3, and TiO2. This study delves into the erosive behaviour of recently created nanohybrid composite materials. The test consistently maintains the following parameters: impact velocity (60–80 m/sec), angle of impact (15° − 90°), standoff distance (ranging from 15 mm to 25 mm), and erodent size (ranging from 300 µm to 500 µm). The results demonstrated that as the impact velocity and erodent size rose, so did the erosion rate. The semi-ductile quality of the manufactured materials is shown by the highest erosion rate at a 60° impact angle. The smallest erosion rate is often seen at an impact angle of 15°, however. The graphene/Kevlar/Epoxy, graphene/SiC/Kevlar/Epoxy, graphene/Al2O3/Kevlar/Epoxy, graphene/TiO2/Kevlar/Epoxy, and Kevlar/Epoxy erosion rates range from 3.27 to 13.08, 6.39 to 14.71, 11.64 to 19.30, 13.52 to 23.35, and 22.19 to 51.61 mg/kg, respectively. In comparison to the erosion values reported for hybrid composite materials based on fillers, these numbers are quite low. When compared to a hybrid composite without nanoparticles, the overall weight reduction for graphene/Kevlar/Epoxy, graphene/SiC/Kevlar/Epoxy, graphene/Al2O3/Kevlar/Epoxy, and graphene/TiO2/Kevlar/Epoxy is 70.67 %-85.25 %, 59.23 %-75.38 %, 41.78 %-64.26 %, and 27.86 %-56.91 %, respectively. This research examines the process of morphological erosion. Examining degraded surfaces with a scanning electron microscope reveals microcracks, crack propagation, pushing action, ploughing action, displacement of fibres, and breaking.

Effect of adding (ZrO2-ZnO) nanopowder on the polymer blend (lamination and methyl vinyl silicone) in a hybrid nanocomposite material

A polymeric blend combines two or more polymers to form a new material with different physical properties. In this work, a base material consisting of a polymeric mixture was manufactured to improve its properties and then strengthened with nanoparticles (ZrO2-ZnO) to develop a hybrid nanocomposite material, which has better properties than its constituent materials. Reinforcement material, i.e., (ZrO2-ZnO) nanoparticles, were prepared using relaxation method. A polymeric resin mixture (lamination and methyl vinyl silicone) was prepared by adding methyl vinyl silicone to the lamination resin in different ratios (4 %, 8 %, 12 %, and 16 %). The mixture properties were studied through tensile, bending, shock, and hardness tests, and the optimal results were achieved for the 12 % ratio. The resulting composite nanoparticles and their properties were studied using EDX, X-Ray, SEM, and PSA techniques. Finally, the nano-hybrid composite material was manufactured by choosing the optimal blend (i.e., 12 %). It had the highest polymeric base material properties, and nanoparticles were added at different dosages (3 %, 6 %, 9 %, and 12 %). The resulting hybrid composite material properties were studied through different tests (tensile, flexural, impact, and hardness). The results showed that the binary composite nanoparticles improved the properties of the mixture for both sizes (30 nm and 89 nm) at all mixing ratios, compared to the control specimens (i.e., without any addition). The optimal results were obtained when 30 nm particles were added and for all tests compared to samples reinforced with 89 nm particles. The optimal ratio of (ZrO2-ZnO) was 9 % wt 30 nm size, representing the best sample in terms of the resulting properties. It is recommended to use the sample with the 9 % addition of (ZrO2 - ZnO) wt with a granular size of (30 nm) in essential applications, including prosthetics (foot).

Superior photocatalytic performance of Dy2O3/graphitic carbon nitride nanohybrid for the oxidation Rhodamine B dye under visible light irradiation: A superoxide free radicals approach

Organic-inorganic hybrid semiconductor nanomaterials have emerged as promising candidates for next-generation energy and environmental solutions. These materials combine organic and inorganic components to form a new class of hybrid nanomaterials with enhanced photocatalytic activity under visible-light irradiation. In this study, g-C3N4 was integrated with different ratios of Dy2O3 using a hydrothermal process. The prepared hybrid composite materials were analysed using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), UV–vis diffuse reflectance spectroscopy (UV-DRS), Brunauer-Emmett-Teller (BET) surface area analysis, field emission scanning electron microscopy (FE-SEM), Energy-dispersive X-ray analysis (EDAX) high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), Photoluminescence Spectroscopy (PL) and Electron Paramagnetic Resonance spectroscopy (EPR). The synthesized Dy2O3/g-C3N4 (DYCN) nanohybrid composite has a bandgap energy and surface area of 2.63 eV and 51.8 m2/g respectively. FE-SEM analysis showed nanorods connected to the sheet-like morphology of the prepared DYCN nanohybrid composite material. When exposed to visible light, the organic dye rhodamine B was used as a model pollutant to assess the photocatalytic activity of the synthesized materials. The oxidation of organic molecules was initiated by superoxide (•O2−) free radicals rather than hydroxyl radicals generated during the reaction, which was confirmed by EPR analysis. Due to its narrow bandgap, larger surface area, and presence of f shells in Dy2O3, the synthesized 5 % Dy2O3/g-C3N4 (DYCN 5) nanohybrid composite material showed more visible-light photocatalytic activity than pure g-C3N4 and various ratios of synthesized nanomaterials.

An Analysis of Water Sorption of Some Composites Used in Dentistry

This study aimed to investigate the water sorption levels of 3 different condensable bulk fill composites, two flowable bulk fill composites, two microhybrid composites, one nanofilled composite, and one nanohybrid composite material polymerized with the same beam device on the 14th and 30th days.We evaluated nine different composite materials. The materials were prepared as cylindrical blocks (n=7) with a diameter of 7 mm and a thickness of 2 mm and polymerized. Each sample was kept in distilled water for specified times and measured by the ISO 4049 method.We used The Kruskal-Wallis test to compare more than two independent groups where numerical variables had no normal distribution. The Dwass-Steel-Critchlow-Fligner test evaluated differences between the groups if the non-parametric tests were applied. We used The Wilcoxon test to compare the numerical variables without normal distribution (water sorption values in the 14th and 30th-day measurements for each cement material).For water sorption, there was no statistically significant difference between the water sorption values of the resin composite materials on the 14th and 30th days. No statistically significant difference was found in comparing water sorption values between the 14th and 30th measurements for each resin composite material. There is a need for more extended studies by keeping the conditions constant for the evaluated composites and for bulk fill composites to be evaluated with 4mm samples.

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 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<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<0.05). In contrast, no statistically significant difference in discoloration was observed after 24 hours and 7 days of immersion (p>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.

An in vitro examination of fluoride ions release from selected materials - resin-modified glass-ionomer cement (Vitremer) and nanohybrid composite material (TetricEvoCeram)

Purpose The aim of this study was to examine a short-term (7 days) fluoride ions release and mechanical properties (microhardness) of dental materials - resin-modified glass- ionomer – Vitremer (3M ESPE) and nanohybrid universal composite - TetricEvoCeram (IvoclarVivadent) to assess whether both materials may constitute effective method of tooth decay prevention. Methods The cylinder-shaped samples were prepared in a special form of a pellet, 2 mm thick and 5 mm in diameter. Specimens were cured with a use of the Bluephase Style 20i lamp (IvoclarVivadent, Schaan, Liechtenstein). Afterwards, they were immersed in the studied solutions. The release of fluoride ions was examined with a use of an ORION 9609 ion-selective electrode (Thermo Fisher Scientific Co., Waltham, MA, USA) connected to a pH/ion meter CPI-551 Elmetron microcomputer. Microhardness measurements were carried out using microhardness tester CSM MicroCombi Tester™ and Indentation 5.21 software. Scanning electron micro-scope (SEM) were created on an FEI Nova NanoSEM 230 microscope (Hills-boro, OR, USA). The magnification was set to 2500x. Results Based on the results, both materials showed similar mechanical properties (microhardness), however cumulated release of F- after 7 days was notably higher from Vitremer in all artificial saliva solutions (1-7). Conclusions Therefore, we can assume that Vitremer has better remineralization potential and it may constitute more effective method of tooth decay prevention.

Effect of Different Decontamination Protocols Applied to Blood-Saliva Contaminated Dentin Surfaces of Universal Adhesive Resin Post-Etch on Shear Bond Strength

ABSTRACT This study was performed to evaluate the effect of different decontamination protocols applied to contaminated surfaces on the recovery of adhesion. Different decontamination protocols were applied to molar teeth contaminated with blood and saliva except the control group. 40 third molar teeth were divided into groups according to the applied decontamination protocols: Group 1(control), Group 2 (water rinse), Group 3 (15-sec re-etch), Group 4 (10-sec re-etch), Group 5 (5-sec re-etch), Group 6 (5% NaOCl), Group 7 (2% chlorhexidine gluconate), Group 8 (ozonated water). Universal adhesive resin (Gluma Universal, Heraus Kulzer) was used in the etch and rinse mode according to the manufacturer’s instructions. Nanohybrid composite material was placed in all groups. Then the Shear Bond strengths of all groups were evaluated after applying 5000 thermal cycles (5–55 °C) to each sample. In the limitation of this in vitro study, it has been shown that rinsing with ozonated water of contaminated surfaces with blood and saliva after etching, has increased the micro-shear bond strength (μSBS) values more than that of in control group values. Also, the application of NaOCl, re-etching with 37% phosphoric acid for 15 seconds, and cleaning with CHX, significantly increase the bonding potential.

Translucency and Color Stability of a Simplified Shade Nanohybrid Composite after Ultrasonic Scaling and Air-Powder Polishing.

We aimed to assess the influence of professional dental prophylaxis on the translucency and color stability of a novel simplified shade nanohybrid composite material. Sixty composite disks (5 mm in diameter and 2 mm thick) of light (n = 30) and dark (n = 30) shades were prepared. The specimens were randomly divided into the following three groups (n = 10) according to the prophylaxis procedure used: ultrasonic scaling, air-powder polishing with sodium bicarbonate, and controls. The specimens were submitted to translucency and color analysis based on the CIELab system. Two measurements were performed before and after 48-h storage in coffee. Translucency values of untreated light and dark specimens were 9.15 ± 0.38 and 5.28 ± 1.10, respectively. Air-powder polishing decreased the translucency of the light composite specimens. Storage in coffee resulted in color changes (∆E) ranging between 2.69 and 12.05 and a mean translucency decrease ranging between -0.88 and -6.91. The samples in the light group tended to exhibit greater staining; the treatment method had no effect on ∆E. It can be concluded that light-shade composite restorations are more prone to translucency and color changes resulting from air-powder polishing and contact with staining media. However, further research using other composites and powders is required.

Transition Metal Dichalcogenides [MX2] in Photocatalytic Water Splitting

The quest for a clean, renewable and sustainable energy future has been highly sought for by the scientific community over the last four decades. Photocatalytic water splitting is a very promising technology to proffer a solution to present day environmental pollution and energy crises by generating hydrogen fuel through a “green route” without environmental pollution. Transition metal dichalcogenides (TMDCs) have outstanding properties which make them show great potential as effective co-catalysts with photocatalytic materials such as TiO2, ZnO and CdS for photocatalytic water splitting. Integration of TMDCs with a photocatalyst such as TiO2 provides novel nanohybrid composite materials with outstanding characteristics. In this review, we present the current state of research in the application of TMDCs in photocatalytic water splitting. Three main aspects which consider their properties, advances in the synthesis routes of layered TMDCs and their composites as well as their photocatalytic performances in the water splitting reaction are discussed. Finally, we raise some challenges and perspectives in their future application as materials for water-splitting photocatalysts.

Adsorption behavior and mechanism of As(V) on magnetic Fe3O4-graphene oxide (GO) nanohybrid composite material.

In this study, the magnetic Fe3O4-graphene oxide (GO) nanohybrid composite material was prepared via the combination of the modified Hummer's method and coprecipitation. The morphology of the hybrid sample showed that the diffusion of Fe3O4 nanoparticles into the porous channels of mesoporous GO layers not only restricted the restacking of GO nanosheets but also prevented the leaching and agglomeration of magnetic nanoparticles. The result of the kinetic and isotherm studies that were performed to evaluate the adsorption mechanism showed a good fit with the pseudo-second-order kinetic and Langmuir isotherm models. The As(V) adsorption efficiency, H, of the GO/Fe3O4 nanohybrid composite material reached the maximum value of 99.37% after 60min. The maximum adsorption capacity qm of the GO/Fe3O4 nanohybrid material was 14.1mg·g-1 in an acidic aqueous solution (pH 1). The role and contribution of GO and Fe3O4 nanoparticles in adsorption and the improvement in As(V) adsorption efficiency were also investigated in further detail. The findings of this work suggested that the GO/Fe3O4 nanohybrid material could be widely applied for polluted water treatment.

Fracture Resistance of Teeth Restored with Newer Methacrylate-Based Dental Composite Materials: An In Vitro Study

Introduction: Composite have evolved significantly due to the increase in the demand for a more esthetic and conservative approach in dentistry. Modifications have been made on the filler particle size and loading, followed by alterations in the resin matrix substance. Methacrylate-based composite with the addition of nanoparticles to the filler has been introduced in the market, providing improved esthetics and lower polymerization shrinkage. The present study was done to compare the fracture resistance of teeth restored using two newer methacrylate-based composite materials, along with the flexural strength of the composites. Methods: Sixty mandibular premolars were divided into two control groups of 10 teeth each and two experimental groups of 20 teeth. Group I − intact teeth with no preparations (n = 10), Group II − prepared but unrestored teeth (n = 10), Group III − teeth prepared and restored with a stackable nanohybrid methacrylate-based composite material (IPS Empress DirectTM), and Group IV − teeth prepared and restored with a packable submicron methacrylate-based composite material (Brilliant EverglowTM), respectively. The teeth were embedded in resin-filled PVC rings, and a compressive loading test was carried out for all groups at a cross-head speed of 0.5 mm/min. The flexural strengths of the two composite materials were also analyzed using three-point bending test using Universal Testing Machine. The statistical significance (P < 0.05) of the differences between the experimental groups was analyzed by ANOVA and Tukey post hoc test. Results: The mean fracture resistance was highest in Group IV (1877.37 ± 494.79) followed by Group III (1763.69 ± 392.51), Group I (1607.08 ± 283.48), and Group II having the least (1442.08 ± 373.66). The mean fracture resistance overall differed significantly between the four groups (P = 0.048). Tukey test showed fracture resistance differed significantly between Group II and Group IV (P = 0.042) and no significance among other groups. Conclusion: Fracture resistance was highest in the group restored with the packable submicron hybrid composite material. The packable submicron methacrylate-based composite material also showed higher flexural strength than stackable nanohybrid composite material.

The Assessment of the Abrasiveness for Resin Composite Finishing &amp; Polishing Systems

Objective: This in vitro study was aimed to assess the abrasiveness of 4 different composite finishing and polishing systems, on two different nano-hybrid composite materials.&#x0D; Methods: 40 composite disc samples were prepared 4 mm in diameter and 2 mm in thickness for each nano-hybrid resin composite (Tetric EvoCeram BulkFill A1 body and IPS Empress Direct A1; Ivoclar Vivadent, Schaan, Lichtenstein; n=80 in total). Each composite group was divided into 4 finishing and polishing system subgroups (Sof-Lex Disc, 3M, St. Paul MN, USA; Enhance&amp;Pogo, Dentsply Sirona, Konstanz, Germany; OptraGloss, Ivoclar Vivadent, Shaan, Lichtenstein; Twist Dia, Kuraray Noritake, Tokyo, Japan; n=10 for each subgroup). Single surface of each sample was roughened with 600 and 800 grit sandpapers (Carbimet, Special Silicone Carbide Grinding Paper, IL, USA), respectively. Initial thickness (t1) was measured for each sample with a digital micrometer (BMI 770150, Germany). Then, 4 different finishing&amp;polishing systems were preformed for one side of the samples, at 10 000 rpm, in dry conditions, by a single operator (30 s for a single materal). Final thicknesses (t2) were measured after finishing&amp;polishing procedures. Statistical analyses were performed regarding t2-t1 values. Two-way Anova test was used to assess the level of abrasion for the composite and finishing&amp;polishing materials. Tukey HSD was used for multiple comparisons.&#x0D; Results: In terms of composite materials, IPS Empress Direct presented significantly a greater level of abrasion (52.85 ± 42.26B) than Tetric Evo Ceram Bulk Fill (p &lt; 0.001). In terms of finishing &amp; polishing materials, significantly a greater level of abrasiveness was observed for Sof-Lex Disc (91.25 ± 47.22b) among all (p &lt; 0.001). There was no significant differences in abrasiveness, between Enhance&amp;Pogo - Optragloss (p = 0.859), Enhance&amp;Pogo - Twist Dia (p = 0. 891), and Twist Dia – Optragloss (p = 0.440).&#x0D; Conclusion: Both the type of composite and the finishing &amp; polishing material were considered effective factors for abrasion. The greatest level of abrasiveness was observed for the 4-step Sof-Lex Disc system (91 µm on average), for the total 120 seconds of application. The abrasiveness for the 2-step systems was similar and ranged between 24 – 36 µm on average, for 60 seconds of application. IPS Empress Direct presented a greater level of abrasion than Tetric Evo Ceram Bulk Fill on equal terms of finishing &amp; polishing.

Effect of dipole–dipole interactions on the one-photon and two-photon photoluminescence in an ensemble of quantum dots doped in a polymer matrix

We have developed a theory for the one-photon and two-photon fluorescence of a nanohybrid composite comprised of an ensemble of quantum dots encased in a matrix of polymer. The quantum dots are comprised of four-level quantum emitters encased within a coating of dielectric material. The fluorescence of the quantum dot system is calculated using the master equation method where dipole–dipole interaction (DDI) coupling is present. The application of a probe field to the nanohybrid composite material in conjunction with the DDI between the quantum dots generates an enhancement of both the single-photon and double-photon fluorescence, and in certain conditions causes spectrum splitting. With a strong DDI field, the two-photon emission spectrum experiences slight quenching and shifts from one peak to two peaks. The dressed states are a result of strong coupling effects between the DDI field and the quantum dots. We generated an analytical expression for the fluorescence spectrum and intensity, and quantitatively compared it to experimental data in which ZnSe quantum dots were embedded within a P3HT polymer film, with our theory strongly correlating with the experiment. We also quantitatively compared our theory with experimental data that demonstrated the single-photon emission spectrum of colloidal quantum dots comprised of a CdZnS/ZnS gradient structure in varying probe field strengths. We found that our theory predicted the spectrum peak splitting that the experiment produced.

ÇÜRÜKSÜZ SERVİKAL BÖLGE DİŞ SERT DOKU KAYIPLARININ RESTORASYONUNDA UNIVERSAL DENTİN BAĞLAYICI AJAN KULLANILARAK FDI KRİTERLERİNE GÖRE DEĞERLENDİRİLMESİ

Aim: This study aimed to compare the different application modes of universal bonding agents on non-carious cervical lesions. Material and method: Twenty-five patients without any systemic disease and with good oral hygiene, having at least 20 teeth and 6 non-carious cervical lesions treated using a universal adhesive and nano hybrid composite material were selected among the patients who were treated at Department of Restorative Dentistry, Eskişehir Osmangazi University between January 2015-March 2015. The 246 restorations included in the study were evaluated according to FDI criteria at 18-month follow-up. Each bonding mode was analyzed by Friedman analysis and Dunn’s binary comparison test. Relation between the categorical mode variate and the scores were analyzed by Pearson Chi-square analysis (p=0.05). Results: There was no significant difference between the application modes at 18-month period regarding surface luster, surface staining, color match and translucency, esthetic anatomical form, marginal adaptation, post operative sensitivity, caries recurrence, erosion, abfraction, tooth integrity and periodontal response. Marginal discoloration, fracture and retention, and the patient's view criterias showed a significant difference in terms of the application modes at 18-month follow-up. Esthetic anatomic form, patient's view, and tooth integrity were not significantly different between evaluation periods (p&amp;gt;0.05). Conclusion: SE mode showed significantly worse scores than that of TE and SLE modes. Further studies are needed to evaluate the clinical performance of universal adhesives.

Comparative Study on the Compressive Strength of a New Ceramic Reinforced Glass Ionomer (Amalgomer CR) and Resin-coated High Strength Glass Ionomer Cement (Equia Forte) with a Nanohybrid Composite Material (Tetric N Ceram) in a Simulated Oral Environment: An In Vitro Study

Comparative Study on the Compressive Strength of a New Ceramic Reinforced Glass Ionomer (Amalgomer CR) and Resin-coated High Strength Glass Ionomer Cement (Equia Forte) with a Nanohybrid Composite Material (Tetric N Ceram) in a Simulated Oral Environment: An <i>In Vitro</i> Study

Preparation and Investigation of Flexural Strength and Impact Strength for Nano Hybrid Composite Materials of the Tri-Polymeric Blend used in Structural Applications

Preparation and Investigation of Flexural Strength and Impact Strength for Nano Hybrid Composite Materials of the Tri-Polymeric Blend used in Structural Applications

The influence of acid etching or chitosan dentin surface treatments on dentin wettability and shear bond strength of self- etch adhesives

The aim of the study was to investigate the influence of dentin surface preparation with acid etching or chitosan treatment on dentin wettability and shear bond strength to resin composite using self-etch adhesive. Methods: Fifteen human sound extracted third molars were used in the study. Dentin disks were cut from the crown for evaluation of dentin wettability, and the remaining part of the crown was used for the shear test. Dentin discs were divided randomly into 3 groups (n=5) treated as follow: G1: control, G2: acid etched with 32% phosphoric acid, and G3: treated with Chitosan for 60 s. Contact angle of treated dentin surfaces with a self-etch single bond universal adhesive was measured using a drop shape analyzer. The remaining crowns used for shear bond strength test (SBS) were divided randomly into three groups (n=5) and prepared in the same manner used for wetting evaluation. Nano-hybrid composite material were bonded to treated dentin surface using self-etch adhesive. Samples were subjected to SBS testing in a universal testing machine. Results obtained, showed statistically significant lower contact angle after chitosan treatment of dentin surfaces as compared to control and acid etched groups (p<0.05). On the other hand, both acid etching and chitosan treatment of dentin surfaces resulted in a statistically significant lower SBS compared to control untreated group (p<0.05).Conclusion: Bonding to dentin using self-etch adhesive is best achieved with direct application of adhesive resin on untreated dentin surface.

An unexpected behavior of a patient after a diastema closure treatment

Bir diastema kapatma işlemi sonrasında hastanın beklenmeyen davranışı Estetik görünümden uzak dişlerin çözümünü bulmak ve estetik restorasyonlar yapmak yeni materyaller ve teknikler sayesinde artık çok kolaylaşmıştır. Hastaların en büyük estetik şikayetlerinden biri maksilla orta hat diasteması’dır. Labial frenulumdan konjenital sebeplere kadar pek çok farklı nedenlerden dolayı orta hat diasteması oluşabilir. Orta hat diastema tedavi tekniklerinden biri dişlerin kompozit materyali ile restore edilmesidir. Wax-up model üzerinde silikon anahtar hazırlanarak kompozit materyalle yapılmış diastema kapatma yöntemi pratik, basit, öngörülebilir ve uygun fiyatlı bir minimal invaziv tekniktir. Bu olgu sunumunda; restoratif diş hekimliğinde yaygın bir tedavi şekli olan diastema kapatma işleminin hastanın model üzerinde onayladığı ve bitim sonrasında da beğendiği restorasyonları daha sonrasında yaşadığı kararsızlık sebebiyle 2 gün içinde söktürtmesi anlatılmaktadır. 24 yaşındaki bayan hasta üst ön dişleri arasındaki ~4mm genişliğindeki diastema şikâyeti ile kliniğimize başvurmuştur. Planlanan tedavi hakkında gerekli bilgilendirmeler yapıldıktan sonra hastamız restorasyonları onayladığına dair onam formunu imzalamış ve tedavilere başlanmış ve nanohibrit kompozit materyal ile restorasyonlar tamamlanmıştır. Sonuç olarak, kararsız hastalarda invaziv bir işleme başlamadan önce, hastanın yeni yapılan restorasyonlara alışma süresi de göz önünde bulundurularak, başlangıç tedavisi olarak kompozit lamina veneerleri tercih etmek çok daha yerinde bir tedavi yöntemi olacaktır.