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Recently, a novel dental restorative composite based on nanostructured micro-fillers of anodic porous alumina has been proposed. While its bulk properties are promising thanks to decreased aging and drug delivery capabilities, its surface properties are still unknown. Here we investigated the surface morphology and the adhesion to tooth dentin of t...
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... organic paste was loaded by sonication-assisted spatulation with 50 wt % APA powder without silane bonding agent and then irradiated under the same conditions as the commercial reference materials. In Table 1, the list of all the EAC ingredients is given, with respective sources and amounts. ...
Citations
... It is well known that the process of osseointegration, consisting of the migration and proliferation of osteoblastic cells and the subsequent synthesis, deposition, and mineralization of the bone matrix, is enormously influenced by the roughness and chemical composition of the surfaces in question, which play a key role in optimizing the biological response. Thus, the morphology of APA and TiO 2 nanotubes has been investigated through Atomic Force Microscopy (AFM), which is considered the gold standard for evaluation of 3D morphology of material surfaces both on the micro-scale and down to nano-sized resolutions [13]. The consequence of better adhesion lies in stronger and more stable contacts between the cells; initially, the less rough surfaces show greater proliferation than the more irregular ones, while in the long run the situation shifts in favor of more uneven surfaces. ...
The possibility of improving dental restorative materials is investigated through the addition of two different types of fillers to a polymeric resin. These fillers, consisting of porous alumina and TiO2 nanotubes, are compared based on their common physicochemical properties on the nanometric scale. The aim was to characterize and compare the surface morphological properties of composite resins with different types of fillers using analytical techniques. Moreover, ways to optimize the mechanical, surface, and aesthetic properties of reinforced polymer composites are discussed for applications in dental treatments. Filler-reinforced polymer composites are the most widely used materials in curing dental pathologies, although it remains necessary to optimize properties such as mechanical resistance, surface characteristics, and biocompatibility. Anodized porous alumina nanoparticles prepared by electrochemical anodization offer a route to improve mechanical properties and biocompatibility as well as to allow for the controlled release of bioactive molecules that can promote tissue integration and regeneration. The inclusion of TiO2 nanotubes prepared by hydrothermal treatment in the resin matrix promotes the improvement of mechanical and physical properties such as strength, stiffness, and hardness, as well as aesthetic properties such as color stability and translucency. The surface morphological properties of composite resins with anodized porous alumina and TiO2 nanotube fillers were characterized by Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), and X-ray chemical analysis. In addition, the stress–strain behavior of the two composite resins is examined in comparison with enamel and dentin.
... Follow-up tests showed that this innovative composite had excellent FM and adhesion strength of dental tissues comparable to commercial composites. 107,108 In addition, the simulations also confirmed the efficacy (stressstrength curve) of the micromechanical interlocking effect to be very similar to that of the conventional fully chemically bonded case. However, the actual obtained FS was still lower than the calculated value by finite element modeling. ...
Dental resin composites (DRCs) are popular materials for repairing caries or dental defect, requiring excellent properties to cope with the complex oral environment. Filler/resin interface interaction has a significant impact on the physicochemical/biological properties and service life of DRCs. Various chemical and physical modification methods on filler/resin interface have been introduced and studied, and the physical micromechanical interlocking caused by the modification of fillers morphology and structure is a promising method. This paper firstly introduces the composition and development of DRCs, then reviews the chemical and physical modification methods of the filler/resin interface, mainly discusses the interface micromechanical interlocking structures and their enhancement mechanism for DRCs, finally give a summary on the existing problems and development potential.
... Aluminium oxide (Al 2 O 3 ) is a ceramic material with great potential for use as a biomaterial in bone implants. In addition to its bioinert nature, Al 2 O 3 can be shaped into a porous structure and still have excellent mechanical properties (Rambo et al. 2006;Böke et al. 2014;Toccafondi et al. 2015;Salerno et al. 2016;Silva et al. 2019). However, it is important to note that bioinert implants, when inserted into the body, are encapsulated by fibrous tissues (Abe et al. 1990). ...
We evaluated the influence of the open porosity of alumina (Al2O3) substrates on the phase formation of calcium phosphates deposited onto it surface. The Al2O3 substrates were prepared with different porosities by the foam-gelcasting method associated with different amounts of polyethylene beads. The substrates were coated biomimetically for 14 and 21 days of incubation in a simulated body fluid (SBF). Scanning electron microscopy characterisation and X-ray computed microtomography showed that the increase in the number of beads provided an increase in the open porosity. The X-ray diffraction and infrared spectroscopy showed that the biomimetic method was able to form different phases of calcium phosphates. It was observed that the increase in the porosity favoured the formation of β-tricalcium phosphate for both incubation periods. The incubation period and the porosity of the substrates can influence the phases and the amount of calcium phosphates formed. Thus, it is possible to target the best application for the biomaterial produced.
... It was shown that the mechanical interlocking of the resin through the pores of the micro-fillers replaces the bonding agent, and the experimental composite-at body temperature and at 1 Hz strain frequency-exhibits better stability on aging for the elastic modulus as compared to standard composites, likely due to the lack of chemical bonding agent degradation after hydrolysis occurring in the wet oral environment. The strength of adhesion of this innovative composite to dental tissue was also characterized in a subsequent experiment [11], resulting in only little lower performance than the average of current ternary restorative composites. The nanoporous nature of the described composite is also promising for drug loading function, eventually enabling antibacterial, or re-mineralizing capabilities of the material [12][13][14]. ...
We fabricated resin composites based on a standard matrix system used for dental restorations incorporating a novel concept microsized filler with passing-through nanopores. The fillers were obtained from anodic porous alumina (APA), after separation from the supporting aluminum substrate and ball milling. Bending tests were carried out on as-cured and artificially aged composites, to determine the material elastic modulus and its strength for the first time. A two-scale modeling was developed; at micro scale, a finite element (FE) model of the representative volume element (RVE) including single APA and surrounding polymer was constructed. The influence of embedded APA length and APA–matrix interaction on the strength was investigated. Then, FE model of the macro-scale RVE containing numerous APA with different orientations based on stochastic modeling was constructed. The output of micro-scale model was used as the input of macro-scale model. The results of simulations allowed to understand better the behavior of the novel composite and interpret the material response deviations from those of common three-phases composites, and to validate the experimental results. The strength of the experimental composite is lower than those of commercial composites used for the same application when as-cured, but is higher after aging.
... One of the main factors that are directly associated with the immediate success and lifetime of a restoration is its surface properties. A rough surface will always increase the adhesion of bacteria and dental plaque deposits, making the tooth more susceptible to infiltration and secondary caries [5]. On the other hand, the presence of excess material and a poorly occluding restored tooth not only damages the tooth itself and its associated periodontium, but also harms the dentition of the opposing arch and the overall health of the stomatognathic system [6]. ...
Background:
The objective of the present study was to compare the outcome of direct composite restorations, with and without the use of additional magnification.
Methods:
Twenty extracted molars were selected for the study. Class 1 Black cavities were prepared. All teeth were etched, and bonding agent was applied. Teeth were assigned randomly into two groups of ten each. Group I: restorations were done without the use of magnification, first by placing a layer of SDR® flow +Bulk Fill Flowable on the base of the cavity, and then restoring the morphology with Ceram.X SphereTEC® One. Group II: the same protocol was applied, but using the dental microscope. Teeth were then evaluated before and after finishing the protocol by 5 dental professionals using a series of established criteria. The results were documented and statistically analyzed using the non-parametric Mann-Whitney test.
Results:
Statistically significant differences were found when using magnification, before the polishing protocol in "marginal adaptation integrity" and "excess material", and after polishing in "marginal adaptation integrity".
Conclusions:
Magnification may be used to increase the quality of the final direct posterior restoration by improving the marginal adaptation integrity, reducing excess material, preventing marginal microleakage, and avoiding subsequent failure.
... In particular, the diminished degradation in elastic modulus on aging was observed at body temperature and at 1 Hz strain frequency. The strength of adhesion of this innovative composite to dental tissue was also characterized in a subsequent experiment [26], resulting in only little lower performance than the average of current ternary restorative composites. ...
A polymer composite based on an innovative filler consisting of microscale powder of nanoporous alumina is modeled. The passing-through nanoscale pores in this system—roughly columnar cylindrical, with diameter of the order of 100 nm—are fully penetrated by the resin, which is not bonded to the inner pore walls by any chemical agent. This system, previously assessed by laboratory experiments, is modeled here for the first time, based on a computational multi-scale hierarchical approach. First, microscale representative volume element (RVE) is modeled in two steps using finite element modeling. Then, the macro-scale RVE is characterized, using a combination of micromechanical rules. The elastic response of the composite is simulated to predict its Young’s modulus. This simulation confirms the former experimental results and helps to shed light on the response of the investigated material, which may represent a novel system for use in disparate composite applications. In particular, the nanoporous microfillers composite is compared with a composite material containing the fillers of the same material yet nonporous, bonded to the matrix. It appears that, with respect to this standard concept of three-phase composites, the presence of the nanopores can compensate for the absence of the bonding agent.
... Depending on the pore size and shape, porosity, and chemical composition of the particles, porous particulate fillers can improve mechanical performance and drug-releasing [84,85]. The typical morphology of a porous filler is shown in Figure 6 [86]. ...
... A novel DRC was proposed based on microfillers of anodic nanoporous alumina. This material exhibited better mechanical properties but seemed prone to aging, and the mechanical properties weakened dramatically when the DRC was loaded with drugs [85]. ...
Dental resin composites (DRCs) with diverse fillers added are widely-used restorative materials to repair tooth defects. The addition of fillers brings an improvement in the mechanical properties of DRCs. In the past decade, diverse fillers have emerged. However, the change of emerging fillers mainly focuses on the chemical composition, while the morphologic characteristics changes are often ignored. The fillers with new morphologies not only have the advantages of traditional fillers (particles, fibrous filler, etc.), but also endow some additional functional characteristics (stronger bonding ability to resin matrix, polymerization resistance, and wear resistance, drug release control ability, etc.). Moreover, some new morphologies are closely related to the improvement of traditional fillers, porous filler vs. glass particles, core-sheath fibrous vs. fibrous, etc. Some other new morphology fillers are combinations of traditional fillers, UHA vs. HA particles and fibrous, tetrapod-like whisker vs. whisker and fibrous filler, mesoporous silica vs. porous and silica particles. In this review, we give an overall description and a preliminary summary of the fillers, as well as our perspectives on the future direction of the development of novel fillers for next-generation DRCs.
... The porous anodic alumina oxide template is widely used in different sectors, such as nanofabrication [16][17][18], bioengineering [19,20], anti-reflection sheets [21,22], surfaceenhanced Raman spectroscopy [23,24] and superhydrophobic surfaces [25]. Application in the optical domain [26] is connected with different values of the effective refractive index of AAO due to its porosity [27]. ...
Porous anodic alumina oxide (AAO) obtained via two-step anodization is a material commonly used as a template for fabricating 1D nanostructures. In this work, copper and cobalt-iron 1D nanocones were obtained by an electrodeposition method using AAO templates. The templates were produced using two-step anodization in H2C2O4. The Co–Fe nanostructures are characterized by homogeneous pore distribution. The electrocatalytic activity of the produced nanomaterials was determined in 1 M NaOH using the linear sweep voltammetry (LSV) and chronopotentiometry (CP) methods. These materials can be used as catalysts in the water-splitting reaction. The sample’s active surface area was calculated and compared with bulk materials.
... This lack of adhesion to dentin is attributed to its organic composition and the fluid that is present in the dentinal tubules. In contrast, the porosity and collagen in the tubules may help to make adhesion stronger [4]. Currently, flowable restorative composites (nano-fillers added to low viscosity monomers) are ideal for many applications, such as pit-and-fissure sealant, small Class III and V restorations, enamel flaws, and incisal edge repairs [5]. ...
... It has been always a great challenge to bond resin-based composites to dentin in comparison to enamel bonding [11,12]. The bond strength of resin composites to dentin could be assessed via numerous techniques like flexural strength and tensile strength [4,13]. However, shear bond strength (SBS) is considered a facile, and commonly adopted method for measuring the bond strength of restorative materials [14,15]. ...
This study aimed to measure and compare the shear bond strength (SBS) of a self-adhering flowable resin composite to dentin with a conventional flowable composite, and evaluate the various modes of failure. Thirty human premolar teeth (n = 30) were randomly allocated to two groups (Group I: Vertise™ Flow; Group II: Filtek Ultimate + Single Bond Universal) of 15 specimens each, and SBS was measured for specimens from each group by applying a shear load using a universal testing machine (UTM). Modes of failure were observed with an optical microscope. An independent-samples T-test was performed to test Levene’s assumption of homogeneity of variance across both groups, with the critical value set at 0.05. The results revealed, that the self-adhering flowable composite (Group I: Vertise™ Flow) resulted in a lower shear bond strength compared with the conventional adhesive system composite (Group II: Filtek Ultimate + Single Bond Universal). Moreover, group I predominantly exhibited non-cohesive failure, which reflects poor bonding to dentin. On the other hand, Group II showed mixed failure for most of the samples, which demonstrated strong adhesive bonding. Therefore, it could be concluded that the self-adhering flowable resin composite (Group I) results in lower SBS to dentin compared with a conventional adhesive system.
... Due to the self-organized electrochemical passivation process, numerous nanostructured oxides were formed on Al [1,2], Ti [3][4][5], W [6], Co [7], Au [8], Fe [9], Sn [10], and Zr [11,12]. The electrochemical nanostructuring of the oxides allowed to achieve improvements in: nanofabrication [13], fabrication of surfaces with tunable wetting contact angle [14,15], renewable energy harvesting and storage [3,5,6,16], sensing [17][18][19], structural color generation [17][18][19][20][21][22], greenhouse gases conversion [4], fabrication of materials with tuned bandgap [23,24], formation of implants [11,12,25] and drug releasing platforms [26][27][28] as well as surface enhanced Raman spectroscopy [29]. Typically, the nanostructures formed via passivation have nanoporous or nanotubular morphology. ...
Electropolished copper foil was passivated in aqueous solution of 1.0 M NaOH at negative potential range vs. silver chloride electrode at room temperature. The passivations were performed at −50, −100, −150, and −200 mV for 1, 5 or 15 h. The resulting nano-needle layers were characterized by X-ray photoelectron spectroscopy and band gaps derived from UV–Vis spectroscopy evidencing coincidence of Cu(OH)2, CuO and Cu2O phases. Scanning Electron Microscopy revealed that the diameter of nanoneedles was not influenced by the passivation potential, however, the nanoneedles diameter was decreasing with extension of the passivation time (the smallest diameter obtained was 60 ± 17 nm). Additionally, the as-prepared oxide nano-needles were found to be polycrystalline, without any post treatments. All together, chemical compositionand physical properties (band gap) show that the inner part of the grown nano-needles is rather made of Cu2O, while outer part, there where the passivation reaction takes place, is made of CuO and Cu(OH)2.
