In this study, a micro-porous titania (TiO sub(2)) layer was synthesized on commercial pure Ti using the microplasma oxidation (MPO) method. Ti/Ti, MPO-TiO sub(2) (MPO-Ti)/Ti and MPO-Ti/MPO-Ti were ...successfully active soldered using this Sn3.5Ag4Ti(Ce) active filler metal at 250 degree C for 60 s. The microstructure and mechanical properties of the active soldered joints were investigated. Results indicate that trace Ce reacts with the MPO-Ti layer to form both CeO sub(2) and Ti, corresponding to the reaction between Ti and Sn to form Ti sub(6)Sn sub(5), and nano-sizes Ag sub(3)Sn phases adsorb at the active filler/MPO-Ti interfaces. Shear strength of soldered Ti/Ti, MPO-Ti/Ti, and MPO-Ti/MPO-Ti specimens were measured to be 16.3 plus or minus 1.39, 11.3 plus or minus 1.56, and 9.5 plus or minus 1.24 MPa, respectively. The fracture of Ti/Ti specimen was found to produce along the Ti sub(2)Sn sub(3) and solder matrix. In the MPO-Ti/MPO-Ti specimen, the fractures occurred through the active filler/MPO-Ti interface. In the MPO-Ti/Ti specimen, the fracture failure mode transferred from MPO layer/Ti interfacial fracture to fracture within the active filler.
Due to the strong horizontal orientation tendency of hexagonal boron nitride (hBN) platelets, hBN/polymer composites generally exhibit high in-plane thermal conductivity while low through-plane ...thermal conductivity. In this work, hBN platelets and aluminum nitride (AlN) particles are used as hybrid fillers to improve the thermal conductivity of polytetrafluoroethylene (PTFE). AlN particles effectively disrupt the alignment of hBN platelets along the lateral direction during the compression processing, which can be proved by the results of SEM and XRD. At 30 vol% filler loading, a high through-plane thermal conductivity as 1.04 W/mK is achieved, which is 3.8 times that of neat PTFE. The significantly increased thermal conductivity is related not only to the synergetic effect of hybrid fillers, but also the reduced in-plane orientation degree of hBN. Hashin-Shtrikman model is also used to quantify the filler connectivity within polymer matrix. The result suggests that filler morphology and orientation influence the filler connectivity and both control the effective thermal conductivity of composites.
Plasticisers are often added to crystallising polymers to improve their processability. Despite many experimental studies, very few modelling studies have been performed to provide fundamental ...understanding of the impact of plasticisers on polymer cyrstallisation kinetics and thermodynamics. In this work, molecular dynamics simulations are used to study crystallisation in a model linear polymer with plasticiser. We first demonstrate that the plasticiser lowers the amorphous phase glass transition, with the extent of the effect increasing with plasticiser concentration, due to increased polymer mobility. Using a model filler surface to induce crystallisation, we find that the plasticiser also reduces crystallisation and melting temperatures. Furthermore, we find that the plasticiser is expelled from the crystals during growth so that its concentration in the amorphous matrix increases with degree of crystallisation. This has a pronounced consequence for crystal melting, and we find a broad temperature range where the crystal is in equilibrium with the amorphous phase, which we rationalise in terms of free energy changes. This has potentially important consequences for the processing of linear polymers such as polyhydroxybutyrate (PHB), poly(l-lactic acid) (PLLA) and polyvinyl alcohol (PVA), by providing the opportunity for processing the polymer in a semicrystalline rather than fully amorphous state.
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•Plasticiser reduces melting and cooling crystallisation temperatures.•Plasticiser inhibits polymer crystal nucleation in isothermal crystallisation.•Plasticiser is expelled from crystals during growth.•Broadened melting curve due to variation of plasticiser concentration in amorphous region.
Cosmetic fillers are frequently used these days for enhancing beauty and to treat wrinkles or sagging skin. However, information on the history of injections may be difficult to obtain, and there is ...a growing number of reports on complications with these agents. In contrast to other imaging techniques, sonography has been successfully used for detecting and identifying common types of cosmetic fillers and has become the first-line imaging modality to deal with these exogenous components.
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.
•Combined effects of K1, K2,V1, V2, R*c1 and R*c2 are considered.•ETC is largely independent of R*c1/R*c2 when the R*c1 + R*c2 is less than 10−4.•ETC is not affected by the TC of filler-1 when K1 ...exceeds a critical value of 103.•The effect of Rc on ETC is influenced by K.•For each sum of Rc, there exists a critical value of R*c1/R*c2.
There has been significant interest in enhancing the effective thermal conductivity (ETC) of polymer by incorporating spherical hybrid fillers. However, the effect of interface thermal resistance (Rc) on the ETC of composites has not been investigated. In this paper, this effect is investigated. Meanwhile, the combined effects of filler thermal conductivities (K1, K2), filler sizes (V1, V2), the Rc sum (R*c1 + R*c2) and the Rc ratio (R*c1/R*c2) are also considered. The results show that for a given K1, K2 and R*c1 + R*c2, the ETC is largely independent of R*c1/R*c2 when the R*c1 + R*c2 is less than 10−4. However, when the R*c1/R*c2 ranges from 10−2 to 10, the competing effects of hybrid fillers Rc have a significant effect on the ETC. The ETC is not affected by the TC of filler-1 when K1 exceeds a critical value of 103, instead becoming dependent on K2. For each sum of Rc, there exists a critical value of R*c1/R*c2 where the ETC reaches its nadir, this critical value is influenced by the R*c1 + R*c2, V and K of two fillers. The Rc of fillers with high K is <10−2, it is not feasible to improve the ETC by continuing to reduce its Rc, this value is 10−4 for fillers with low K.
To evaluate the influence of filler geometry and viscosity of luting composites on marginal adhesive gap width (MGW) and occlusal surface height (OSH) of all-ceramic partial crowns.
Forty-eight ...all-ceramic partial crowns (Celtra Duo, Dentsply) were created and divided into six groups (n = 8). Restorations were bonded using universal adhesive (Prime & Bond Active, Dentsply) in combination with low-viscosity composites (LV) containing amorphous fillers (Calibra Ceram, Dentsply) (LV-AF), heterogeneous fillers (Tetric EvoFlow, Ivoclar Vivadent) (LV-HF) vs. high-viscosity composites (HV) containing spherical fillers (Ceram.x, Dentsply) (HV-SF) or heterogeneous fillers (Tetric EvoCeram, Ivoclar Vivadent) (HV-HF). HV materials were used either with or without sonication. MGW µm was measured by SEM. Displacements of the restorations after luting, such as changes (Δ) in OSH µm, tilting and rotation °, were measured using a dial gauge and 3D-analytical software (OraCeck, Cyfex). Statistical analysis was by Mann-Whitney U-test and t-test with α = 0.05.
MGW (p = 0.002) and tilting (p = 0.001) were significantly smaller with LV (228.0 ± 112.35 µm; 0.89 ± 1.25°) than with HV (338.1 ± 97.26 µm; 1.95 ± 1.26°). Sonication had no effect on MGW in HV-HF (332.32 ± 91.39 µm) and HV-SF (343.85 ± 105.48 µm; p = 0.74). Sonication decreased ΔOSH by ~50% with HV-SF (64.21 ± 27.90 µm) but remained unchanged with HV-HF (39.06 ± 14.08 µm; p = 0.004). There was no difference in rotation between HV (0.82 ± 0.81°) and LV (0.61 ± 0.74°; p = 0.29). The LV-AF and LV-HF groups showed no statistical differences in MGW, ΔOSH, tilting or rotation (p > 0.05).
Irrespective of filler geometry and insertion technique, the use of high-viscosity composites for the adhesive cementation of modern all-ceramic partial crowns increases displacement, marginal misfit and occlusal surface height.
•Using high-viscosity composites for luting ceramic partial crowns causes marginal misfit•Viscosity of the luting material determines occlusal surface height after luting•Low-viscosity luting materials facilitate seating of ceramic partial crowns
Failure of dental treatments is mainly due to the biofilm accumulated on the dental materials. Many investigations have been conducted on the advancements of antimicrobial dental materials. Polymeric ...and inorganic nanoscopical agents are capable of inhibiting microorganism proliferation. Applying them as fillers in dental materials can achieve enhanced microbicidal ability. The present review provides a broad overview on the state-of-the-art research in the field of antimicrobial fillers which have been adopted for incorporation into dental materials over the last 5 years. The antibacterial agents and applications are described, with the aim of providing information for future investigations.
Microbial infection is the primary cause of dental treatment failure. The present review provides an overview on the state-of-art in the field of antimicrobial nanoscopical or polymeric fillers that have been applied in dental materials. Trends in the biotechnological development of these antimicrobial fillers over the last 5 years are reviewed to provide a backdrop for further advancement in this field of research.
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Background
Treatment of a sunken appearance of the temporal region using injectable fillers is a popular procedure. The temporal fossa has very complex anatomy due to multiple vessels running in the ...different tissue layers. A severe complication in the form of non-thrombotic pulmonary embolism (NTPE) can occur as a result of an inadvertent injection in the middle temporal vein (MTV) while performing temporal fossa filler procedures. Therefore, in-depth knowledge and understanding of the MTV anatomy are essential for successful and safer injectable procedures of the temporal fossa.
Objectives
While there have been many studies to describe the arteries in this region, there is limited information about the location and course of the middle temporal vein. This literature review is aimed at providing detailed information about the course, depth, and size of the MTV to help aesthetic practitioners in performing safer temporal fossa filler injections. This information is imperative to delineate the ‘venous danger zone’ in the temple region.
Methods
The preferred reporting items for systematic reviews and meta-analyses guidelines were used for this review. A literature search was performed to find the articles providing details about the MTV anatomy and the measurements related to its course and size.
Results
A review of the literature showed that the MTV displays a consistent course and depth in the temporal region, with high variability in its diameter. The middle temporal vein width varied between 0.5 and 9.1 mm in various studies. The middle temporal vein receives many subfascial tributaries from the surface of the temporalis muscle, and for most of its course runs in the fat pad enclosed between superficial and deep layers of the deep temporal fascia. A ‘venous danger zone,’ in the interfascial planes of the temporal fossa, which contain the main part of the MTV and its tributaries, has been proposed in this paper.
Conclusions
The temporal fossa filler procedures need great caution, and knowledge of the depth and course of the MTV is essential for avoiding NTPE.
Level of Evidence III
This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors
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The research on the properties of epoxy asphalt mastic is very important due to its performance being closely related to that of epoxy asphalt mixture. This study evaluates the viscosity evolution, ...tensile properties, high temperature stability, low temperature crack resistance, and fatigue resistance of epoxy asphalt mastic at varying filler to asphalt ratios (F/A), and compare its performance to those of matrix asphalt mastic and SBS asphalt mastic. Besides, the surface morphology of epoxy asphalt mastic is observed through a stereo microscopy. The results show that as the F/A increases, the viscosity of epoxy asphalt mastic increases; the tensile strength increases, while the elongation at break decreases; high temperature stability first increases followed by a decrease, with optimal performance at the F/A range of 0.8–1.4; fatigue resistance first increases followed by a decrease as well, with optimal performance at the F/A range of 0.6–1.2; the rigidity increases at low temperature, but the crack resistance decreases. The optimal F/A range for best overall performance is determined as 0.8–1.2. Compared with matrix asphalt mastic and styrene-butadiene-styrene (SBS) asphalt mastic, epoxy asphalt mastic shows excellent stability at high temperature and fatigue resistance under low applied strain, except that the crack resistance of it at low temperature becomes less sensitive to changes in limestone fillers content when the F/A is greater than 0.6. Stereo microscopic imaging reveals that limestone fillers evenly disperse in epoxy asphalt at low F/A, with agglomeration occurring when F/A exceeds 1.8. This study highlights the unique performance advantages of epoxy asphalt mastic, and provides essential insights into application of epoxy asphalt mastic in pavement engineering.
•Analyze the viscosity properties and tensile performance of epoxy asphalt mastic.•Explore the high temperature stability, low temperature crack resistance and fatigue resistance of epoxy asphalt mastic.•Determine the optimal range of filler to asphalt ratio for epoxy asphalt mastic.•Compare the properties of epoxy asphalt mastic, base asphalt mastic and SBS asphalt mastic.•Use a digital stereo microscope to observe the morphology of epoxy asphalt mastic.
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