Residual Impression Research Articles

Exploring the high-temperature deformation behavior of monocrystalline silicon – An advanced nanoindentation study

Knowing the mechanical behavior of silicon at elevated temperatures is crucial for many high-temperature applications and processes. This work aims to expand the knowledge of these properties, especially on length scales relevant to miniaturized silicon structures. Therefore, nanoindentation experiments were performed on two differently doped (1 0 0) silicon wafers with varying oxygen content, from room temperature up to 950 °C. Residual impressions were microscopically characterized via confocal laser scanning microscopy. From this dataset covering an exceptionally large temperature range the elastic modulus and hardness as well as strain rate sensitivity, activation volume, and energy were evaluated. Generally, a change in deformation behavior can be identified between 300 °C and 400 °C. Above this transition temperature, the hardness drops exponentially. Also, the material becomes strain rate sensitive. These observations support the assumption that the deformation mechanism shifts from high-pressure phase transformation to dislocation-controlled plasticity with increasing temperature. Furthermore, a change in strain rate sensitivity, activation energy, and activation volume above 800 °C implies a further shift in the rate-controlling mechanism of dislocation motion. Lastly, the more strongly doped sample with the higher oxygen content showing higher mechanical strength is discussed regarding solid-solution strengthening and dislocation locking by oxygen atoms.

Grain boundary softening from stress assisted helium cavity coalescence in ultrafine-grained tungsten

The formation of helium cavities in coarse-grained materials produces hardening proportional to the number density and size of the cavities and due to the interaction of dislocations with intragranular helium defects. In nanostructured metals containing a high density of interfacial sinks, preferential cavity formation in the grain boundaries instead produces softening that is often attributed to enhanced interfacial plasticity. Employing two grades of ultrafine-grained tungsten, we explore this effect using targeted implantation studies to map cavity evolution as a function of the irradiation conditions and quantify its impact on the mechanical response through nanoindentation. Softening is reported at implantation temperatures above the threshold for preferential grain boundary cavity formation but at a sufficiently low fluence prior to the growth of intragranular cavities. Collective changes in the mean cavity size, density, and morphology beneath a residual impression on an implanted surface indicate that cavity coalescence accompanied the reduction in hardness. Complementary atomistic simulations demonstrate that, in tungsten grain structures exhibiting softening, grain boundary bubble coalescence is driven by stress concentrations that further act to localize strain in the grain boundaries through cooperative deformation processes involving local atomic shuffling and sliding, dislocation emission, and even the nucleation of unstable twinning events.

Nanoindentation size effects of mechanical and creep performance in Ni-based superalloy

Nanoindentation technique was adopted to study indentation size effects of physical-mechanical and creep performance with various depths (200–2000 nm) in GH901 utilising sharp and spherical tip. Residual impressions of both indenters with pile-up patterns are discussed. Nanohardness, reduced modulus and elastic recovery rates curves versus maximum displacement of two tips are obtained and nanohardness size effects are discussed with different models for Berkovich tip. The data obtained with spherical indentation are analysed separately by establishing stress–strain diagram. The creep results using Berkovich tip indicate that creep strain rate declines while creep stress exponent first decreases and then increases with the increasing depth; the creep stress exponent (n) values, 2.39–7.35, imply the dominant creep deformation mechanism is dislocation control.

Effects of nanoindents on the martensitic transformation of Ni-Mn-Ga shape-memory Heusler films: A study by high-resolution imaging as a function of temperature

Nanoindentation was used to analyze the effect of localized plastic deformation on the martensitic transformation of epitaxial Ni-Mn-Ga films on MgO(001) substrate. Atomic and magnetic force microscopy imaging at elevated temperature was applied to study the martensitic transformation route from the nanometer to the micrometer scale. We analyzed the cooling and heating curves for the martensitic transformation of the nanoindented areas as a function of the applied loads as well as the distance from the material pile-ups around the residual impressions. We observe a thermodynamically governed local increase of the martensitic transformation temperature (i.e. martensite stabilization) as a function of the applied loads. The local increase of the transformation temperature vs. the applied load (P) follows a non-linear regime: reducing the slope by increasing the applied load and showing a plateau for P ≥ 5 mN. The observed effect is local and almost disappears for distances larger than 500 nm from the pile-ups around the residual impressions, where the material transforms similar to the pristine sample. The local increase of transformation temperature as a function of nanoindentation loads is the dominant effect and occurs in both the cooling and the heating curves. Therefore, no considerable thermal hysteresis variation is observed in the transformation of the material. Moreover, we report in average ∼12% higher relative areal shift of the transformation curves over cooling than heating close to the indents reflecting an unequal impact of indents on TM and TA in Ni-Mn-Ga.

Effect of Macro, Micro and Nano Loads on The Indentation Behavior of Ti-6Al-4V and Haynes 242 Alloys

Indentation tests were conducted on Ti-6Al-4V and Haynes 242 alloys at macro, micro and nano load range using conventional and depth-sensing indentation instruments to study the load effects on the mechanical behaviour of the alloys. With the increase of indentation loads from macro to nano, a decrease in Young’s modulus and indentation hardness values was observed as a result of the indentation size effect in the alloys. During the loading procedure in macro, micro and nano indentations, the loading curves progressively moved upwards, showing the increase in resistance of the alloys with the increase in indentation load. Compared the depth-sensing instrumented indentation hardness of alloys with the conventional indentation hardness at micro loads, the magnitude of the depth-sensing instrumented indentation hardness is 10-25% greater than the conventional indentation hardness. The reason for this variation is explained as the depth-sensing instrumented indentation hardness is calculated at maximum load with the projected contact residual impression area, Ac, instead of the residual indenter impression projected area, Ar. So the indent pileup and sink-in play a major difference between the depth-sensing instrumented hardness and conventional indentation hardness. The outcome of the experimental work clearly indicates that for evaluation of the hardness usage of projected contact residual impression area provides more accurate results than when residual indenter impression projected area is used. The concept is synonmous to evaluation of engineering stress / strain and true stress / strain using original and actual cross sectional area respectively.

MANAJEMEN ASUHAN KEBIDANAN ANTENATAL PADA NY "N" DENGAN ABORTUS INKOMPLIT DI RSUD SYEKH YUSUF KAB. GOWA TAHUN 2019

Introduction Incomplete abortion is the loss of some of the product of conceptiononof pregnancy, causing some of the fetal tissues are still deposited in the uterus such as decidua and placenta. During the process, the initial sign isthe bleeding in the basal decidua followed by the occurrence of necrosis in the surrounding tissue. Afterwards, a part if not all of the conception product would be detached. As it is considered to be a foreign object, the uterus would contract to expel it. At week 8 of gestation, all of the products of conception would be excluded because the choreal villi had not deeply penetrated the decidua. At weeks 8-14 of gestation, the choreal villi already deeply entered the decidua. Therefore, at this stage, some of the conception would come out and some would remain which causes the bleeding on the mother. Method This case study investigated the case of incomplete Abortion on Mrs. “N” at Public Regional Hospital of Syekh Yusuf in Gowa Regency. This study was conducted by employing 7- stages midwifery care approach suggested by Helen Varney and SOAP documentation procedure. The results of the case study conducted on Mrs. “N” indicated that the patient got an incomplete abortion case based on an anamnesis and physical examination taken. Mrs. "N", came to the regional hospital of Syekh Yusuf Gowa with the complaint of bleeding from her birth canal. The patient said that she had been bleeding since October 5, 2019 which stopped after wards. On October 30, 2019 at 6:00 a.m., there was blood as a result of her massage a couple of weeks before. The condition of the patients was considered to be weak, composmentis with the blood pressure of 110/70 mmHg. Her uterine fundal height was not palpable, and her ostium uteri externum and internum were closed. Based on the ultrasound examination with her residual tissue impression, uterine anteflexion, and FL (-), the patient was possibly diagnosed to get an incomplete abortion. Therefore, curettage was administered. On the first day after the curette, the patient’s condition improved. There was some bleeding and pain felt from the vagina, particularly from her lower abdomen. However, in general, the curettage was considered to be successful in which no obstacles were found during the implementation of the procedure. Conclusion After conducting an assessment and analysis based on the 7-stages of Varney and SOAP documentation procedure, it was apparent that the diagnosis given to Mrs “N” was the incomplete abortion case. Therefore, curettage was administered to the patient, and it had been succesfully conducted by the health workers in the hospital.

Length-scale-dependent stress relief mechanisms in indium at high homologous temperatures.

Nanoindentation and electron microscopy have been used to examine the length-scale-dependent stress relaxation mechanisms in well-annealed, high-purity indium at a homologous temperature of 0.69. The experimental methods, analysis, and observations serve as a stepping stone in identifying the stress relaxation mechanisms enabling the formation and growth of metallic dendrites originating at the buried interface between a metallic anode and a solid electrolyte separator. Indium’s load–displacement data are found to be very similar to that of high-purity lithium. Residual hardness impressions show two distinct surface morphologies. Based on these morphologies, the measured hardness, and the estimated pile-up volume, it is proposed that residual impressions exhibiting significant pile-up are the result of deformation dominated by interface diffusion. Alternatively, impressions with no significant pile-up are taken to be the result of shear-driven dislocation glide. An analytical model is presented to rationalize the pile-up profile using interface diffusion.

Effect of Indentation Load on Raman Spectra of the InP Crystal

In this study, the Raman spectroscopy method was used for examination of structural changes made on the (001) surface of InP crystal using nanoindentation with a maximum load up to 100 mN. The presence of the metallic, high-pressure B1 phase of InP was not confirmed. Consequently, this result indicates a dislocation-governed mechanism of nanoindentation induced incipient plasticity of InP crystal. An increase in the maximum load caused a decrease in the width as well as a shift in the main Raman bands (LO, TO) into lower frequencies. Our findings were explained under assumption that an increase in the maximum load causes a decrease in both the dislocation density and the stresses in the vicinity of residual impressions. This unexpected relationship was confirmed by results of nanoindentation experiments.

Effect of Sample Tilt on Indentation and Scratch Behavior of Single Crystal Copper

Inclined factors bring a lot of errors to indentation and scratch experiments. The aim of this paper is to investigate the effect of sample tilt on indentation and scratch behavior of single crystal copper. Angled indentation and scratching experiments were conducted on the flat of 5°,10°,15° and 30°, and spherical-conical indenter was used to study the effect. In scratching simulation with SPH method, normal and lateral forces during scratching process increased when tilt. Contrary to simulation result, when contact depth was held as a constant, the forces declined as tilt angle increased. In geometry model, the actual indentation depth was less than the theoretical contact depth and the projected area of the tilt indenter was an enclosed area like an elapse with two circular arcs. Residual impression images of indentation and scratching indicated that not only the sphere section of the tip of indenter, but also the conical surface penetrated into sample and squeezed a slope. The results showed that the size of spherical-conical indenter has significant effects on the size and shape of wear debris and could not be neglected during indentation and scratching tests with sample tilt.

Structural characteristics of central depression belt in deep-water area of the Qiongdongnan Basin and the hydrocarbon discovery of Songnan low bulge

The Qiongdongnan Basin has the first proprietary high-yield gas field in deep-water areas of China and makes the significant breakthroughs in oil and gas exploration. The central depression belt of deep-water area in the Qiongdongnan Basin is constituted by five sags, i.e. Ledong Sag, Lingshui Sag, Songnan Sag, Baodao Sag and Changchang Sag. It is a Cenozoic extensional basin with the basement of pre-Paleogene as a whole. The structural research in central depression belt of deep-water area in the Qiongdongnan Basin has the important meaning in solving the basic geological problems, and improving the exploration of oil and gas of this basin. The seismic interpretation and structural analysis in this article was operated with the 3D seismic of about 1.5×104 km2 and the 2D seismic of about 1×104 km. Eighteen sampling points were selected to calculate the fault activity rates of the No.2 Fault. The deposition rate was calculated by the ratio of residual formation thickness to deposition time scale. The paleo-geomorphic restoration was obtained by residual thickness method and impression method. The faults in the central depression belt of deep-water area of this basin were mainly developed during Paleogene, and chiefly trend in NE-SW, E-W and NW-SE directions. The architectures of these sags change regularly from east to west: the asymmetric grabens are developed in the Ledong Sag, western Lingshui Sag, eastern Baodao Sag, and western Changchang Sag; half-grabens are developed in the Songnan Sag, eastern Lingshui Sag, and eastern Changchang Sag. The tectonic evolution history in deep-water area of this basin can be divided into three stages, i.e. faulted-depression stage, thermal subsidence stage, and neotectonic stage. The Ledong-Lingshui sags, near the Red River Fault, developed large-scale sedimentary and subsidence by the uplift of Qinghai-Tibet Plateau during neotectonic stage. The Baodao-Changchang sags, near the northwest oceanic sub-basin, developed the large-scale magmatic activities and the transition of stress direction by the expansion of the South China Sea. The east sag belt and west sag belt of the deep-water area in the Qiongdongnan Basin, separated by the ancient Songnan bulge, present prominent differences in deposition filling, diaper genesis, and sag connectivity. The west sag belt has the advantages in high maturity, well-developed fluid diapirs and channel sand bodies, thus it has superior conditions for oil and gas migration and accumulation. The east sag belt is qualified by the abundant resources of oil and gas. The Paleogene of Songnan low bulge, located between the west sag belt and the east sag belt, is the exploration potential. The YL 8 area, located in the southwestern high part of the Songnan low bulge, is a favorable target for the future gas exploration. The Well 8-1-1 was drilled in August 2018 and obtained potential business discovery, and the Well YL8-3-1 was drilled in July 2019 and obtained the business discovery.

Enhancement of the in-plane and pin-load bearing behavior of a quasi-isotropic carbon fiber/epoxy matrix multi-scale laminate by modifying the fiber-matrix interphase using graphene nanoplatelets

The present work examines the effect of incorporating two different concentrations, 0.1% and 0.25%, of silane-functionalized graphene nanoplatelets GnP-GPTMS onto the carbon fiber surface of a quasi-isotropic laminate with the aim to enhance both, the laminate in-plane and the bearing strength, in a pin-loaded joint. Delamination damage modes associated with high-stress gradients were also suppressed in the in-plane loaded laminates, significantly increasing load-carrying capability. The bearing strength of a pin-loaded hole is correlated to the tensile, compression, and shear properties. The results showed an improvement of 13.8% in tensile strength for the 0.1% GnP-GPTMS concentration, as well as 17.3% for compressive strength, while for shear strength, the improvement was 11.89% for the laminate. On the other hand, the behavior of the material in the pin-loaded joint showed an increase of 10.83% for the bearing strength with the 0.1% GnP-GPTMS, fiber surface treatment. Distinct differences were noticed between the tensile stress-loaded area and the area of the residual impression of the pin in the failure mode between the only-resin treated carbon fiber composites and GnPs treated fibers. It was evident, that the interfacial shear strength (IFSS) played an important role on the failure mode. In the compression area in the pin-loaded region, there was a marked presence of a permanent deformation in the matrix. With a closer look at the local failure phenomena at the compression loaded area, there was no fiber kinking and the degree of matrix plasticity disappeared according to the level of interfacial adhesion.

Revealing the Plastic Mode of Time-Dependent Deformation of a LiTaO3 Single Crystal by Nanoindentation.

Recently, instrumental nanoindentation has been widely applied to detect time-dependent plastic deformation or creep behavior in numerous materials, particularly thin films and heterogeneous materials. However, deformation mechanism at nanoindentation holding stage has not been well revealed hitherto. In the current work, nanoindentation holding tests with high loads were performed on a brittle LiTaO3 single crystal. The surface morphologies of residual impressions with various holding times were investigated. It was indicated that generation of secondary cracks and propagation of both main and secondary cracks were the dominating mechanism for time-dependent plastic deformation at the initial holding stage, and the density and length of cracks were invariable at the steady-state holding stage, which suggested a nonlocalized plastic deformation beneath the indenter. It could be concluded that time-dependent plastic deformation of brittle ceramic under nanoindentation is composed of instant cracking as the continuation of loading sequence and homogeneous creep flow by high shear-compression stress at room temperature.

Compressive Properties of Nanoporous Gold Through Nanoindentation: An Analytical Approach Based on the Expanding Cavity Model

We investigated the analytic relation between hardness and compressive yield stress using an expanding cavity model (ECM) for nanoporous gold (np-Au). We prepared three np-Au samples with ligament sizes 30.61, 59.36 and 116.33 nm by free-corrosion dealloying and post heat treatment. The indentation contact morphology was examined to estimate the hardness accurately from the nanoindentation load-depth curve. Unlike conventional dense metals, the deformation was confined to the projected contact area, and the center of the residual impression was dominated by densification. The projected contact area estimated by the Oliver–Pharr method was overestimated, so that a new contact area function was proposed that considered the indentation contact morphology of np-Au. It was confirmed that a hardness value taking into account the indentation contact morphology of np-Au matches well with the hardness derived by direct measurement of the residual impression. We modeled the ratio of hardness to compressive yield stress for np-Au using an ECM. The scaling factors, which represent the extra strain-hardening in the core in the ECM, were analyzed for np-Au and dense metals. An ECM that better matches np-Au is suggested based on the scaling factor resulting from densification beneath the indenter.

Modified fiber reinforced concrete for industrial floors

The main requirements to gain of strength, impact resistance without increasing brittleness, durability of concrete for industrial floors are increasing. It has been shown that the strength of concrete at the impact loads can be increased by means of regulation of the macro-, micro- and nanostructure parameters of the concrete. The kinetics of hardening, peculiarities of pore structure and impact resistance of concrete reinforced with polypropylene fiber and modified by polycarboxylate ether superplasticizer, micro- and nanofine mineral additives are investigated. Nanomodified concretes are characterized by increased rate of early strength development (fcm2/fcm28=0.55) and strength after 28 days (101.5–104.9 MPa), which meets the requirements for rapid hardening high strength concrete. Impact resistance of modified fiber reinforced concrete is determined according to special procedure, which estimate parameter of maximum weight after which the residual impression depth on the surface from impact does not exceed the permissible value (2 mm). The impact resistance of concrete modified with polycarboxylate superplasticizer is 100 and 150 N after 28 and 360 days respectively. Nanomodified fiber reinforced concrete is characterized impact resistance 200 N after 28 and 360 days.

Temperature dependence of indentation behavior of Ti-6Al-4V alloy for bio medical applications

Numerical analysis of spherical indentation was carried out to study temperature dependence (300-673K) of elasto-plastic deformation behavior of Ti-6Al-4V alloy. Flow stress and strain hardening exponent ‘n’ were determined from load versus indenter penetration depth profiles generated through FE model using Dao’s reverse analysis approach. The upward flow around the residual impression as a function of average strain, which describes the strain hardening behaviour of the alloys was also investigated. The simulated values of CF have been used to predict high strain-rate plastic flow behavior considering indentation data. It was observed that there is a good correlation between data from simulation and experimental results in the literature. The FE model developed in the current investigation can be used for simulating the flow behavior of Ti-6Al-4V alloy. The temperature dependent CF value in the fully plastic regime from the current study is approximately 2.69 against experimentally evaluated value of 2.95. Meyer’s hardness is generally high due to the presence of cold layer resulting from grinding and polishing of the test specimen. Absence of such effects in simulation of spherical indentation resulted in reduced value of CF.

Avoidance of Interaction between Impression Materials and Tooth Surface Treated for Immediate Dentin Sealing: An In Vitro Study.

Immediate dentin sealing (IDS) is an advantageous approach for realizing adhesive restorations, but it interferes with the polymerization of impression material due to the oxygen-inhibition layer (OIL), which leaves residues of impression material on the teeth. The aim of this study is to identify a clinical surface cleaning protocol after IDS in order to achieve defect-free impressions. Sixty extracted human teeth were cut to expose fresh dentin and the IDS protocol was performed. Samples were divided into six groups where different surface cleaning protocols were made before taking impressions: G1S and G1P groups, IDS and silicone (S) or polyether (P) impressions; G2S and G2P, treatment with prophy paste and impressions; G3S and G3P, final cleaning phase with surfactant agent and impressions. Teeth were evaluated with a scanning electron microscope to identify the areas (expressed in mm2) where residual impression material was present. The results demonstrate a reduction of residues in the G2 groups and the total disappearance in G3 groups with statistically significant differences between them. Superficial cleaning protocols with the prophy paste and surfactant agent lead to the elimination of the interaction with impression materials and OIL. These results suggest a safe clinical protocol for obtaining defect-free impressions after IDS.

Use of indentation to study the degradation of photovoltaic backsheets

The ability of electrical insulating materials within a module to act as insulators is a key safety requirement for photovoltaic (PV) technology. Presently, however, the durability of backsheets may not be readily assessed. For example, the mechanical tensile test continues to be developed, and its use has not been validated such that a technically based pass/fail criteria may be established. This study examines the use of simple indentation methods, including durometer hardness and instrumented indentation, as a means to quantitively assess the degradation of PV backsheets. Characteristics including: hardness, modulus, load/displacement profile, creep hold response, and residual impression are explored in an empirical study. Glass/encapsulant/backsheet mini-modules constructed using backsheets including: polyamide (specifically the AAA backsheet product), poly(ethylene terephthalate) (PET), polyvinyl fluoride (PVF) laminate (“TPE”), and polyvinylidene fluoride (PVDF) were examined. An M-type durometer as well as Berkovich and cube-corner tips were used in the indentation experiments. Additional characterizations were performed to interpret the indentation measurements including: surface roughness measurements using atomic force microscopy (AFM), a chemical structure study using Fourier-transform infrared spectroscopy (FTIR), and phase-transition measurements using differential scanning calorimetry (DSC). The results are analyzed in the context of the combined accelerated stress test (C-AST) also explored in this study. Instrumented indentation (i.e., using a Berkovich tip) was able to distinguish between backsheets and quantify the effects of accelerated testing (including up to 60%, 25%, and 20% change in hardness, modulus, and creep displacement, respectively). The embrittlement of the backsheets was not readily assessable using cube-corner indentation. Cracking of the known-bad polyamide backsheet was observed from the C-AST, which was not observed to result from steady state UV weathering.

Size Effect in Single Crystal Copper Examined with Spherical Indenters

The increasing hardness with decreasing penetration depth, referred to as indentation size effect (ISE) was previously investigated experimentally and theoretically by many researchers, however the mechanisms responsible for ISE are still being discussed. Generally, ISE is related to the density of geometrically necessary dislocation stored within a small volume beneath the indenter tip. In this study ISE is investigated experimentally in a single crystal copper using spherical indenter tips of different radii. Some new aspects of ISE are shown: a qualitative change of shape of residual impression (pile-up/sink-in pattern) when tip radius or load is modified, an increase of maximum pop-in load with decrease of tip radius as well as the well-known increase of hardness when tip radius decreases are analyzed. As we observe a difference of the residual imprint morphology which depends on tip radius and load, we apply two methods of hardness estimation: true hardness and nominal hardness. The former is determined on the basis of direct measurement of the contact area while accounting for a specific pile-up pattern, while the latter is determined by measuring the contact area using residual penetration depth. We show that hardness–tip radius relationship has a linear form for the nominal hardness and bilinear form for the true hardness.

Hexagonal germanium formation at room temperature using controlled penetration depth nano-indentation

Thin Ge films directly grown on Si substrate using two-step low temperature growth technique are subjected to low load nano-indentation at room temperature. The nano-indentation is carried out using a Berkovich diamond tip (R ~ 20 nm). The residual impressions are studied using ex-situ Raman Micro-Spectroscopy, Atomic Force Microscopy combined system, and Transmission Electron Microscopy. The analysis of residual indentation impressions and displacement-load curves show evidence of deformation by phase transformation at room temperature under a critical pressure ranging from 4.9GPa–8.1GPa. Furthermore, the formation of additional Ge phases such as r8-Ge, hd-Ge, and amorphous Ge as a function of indentation depth have been realized. The inelastic deformation mechanism is found to depend critically on the indentation penetration depth. The non-uniform spatial distribution of the shear stress depends on the indentation depth and plays a crucial role in determining which phase is formed. Similarly, nano-indentation fracture response depends on indentation penetration depth. This opens the potential of tuning the contact response of Ge and other semiconductors thin films by varying indentation depth and indenter geometry. Furthermore, this observed effect can be reliably used to induce phase transformation in Ge-on-Si with technological interest as a narrow band gap material for mid-wavelength infrared detection.

Effect of Immediate Dentin Sealing on Polymerization of Elastomeric Materials: An Ex Vivo Randomized Controlled Trial.

ABSTRACTStatement of problemInteractions are suspected between resin coating and elastomeric impression material.PurposeThe purpose of this study was to identify possible interactions between two impression materials and resin-coated tooth surfaces.Materials and methodsExtracted molars (n = 10) underwent 1 of the 4 procedures: control group (unsealed tooth surface/impression); IDS group (immediate dentin sealing/impression); IDS/AB group (immediate dentin sealing/air blocking/impression); IDS/AB-P group (immediate dentin sealing/air blocking/pumicing/impression). Dentin bonding agents used were Adper single bond 2 and Clearfil SE bond. Impression materials used were Impregum Soft (polyether) and Aquasil (A silicone). A stereomicroscope was used to detect any residual impression material on the bonded tooth surface.ResultsThe IDS group showed 100% faulty impressions. Air blocking the resin coating did not completely eliminate the oxygen-inhibited layer of Adper single bond 2. Clearfil SE Bond along with Aquasil generated ideal impressions in group IDS/AB, while all other combinations resulted in faulty impressions. The IDS/AB-P group yielded ideal impressions with Aquasil but generated faulty impressions with Impregum soft in most specimens.ConclusionImmediate dentin sealing should be followed by air blocking and pumicing to generate ideal impressions with Aquasil (A silicone). Impregum Soft (polyether) is not recommended in combination with immediate dentin sealing.How to cite this articleKhakiani MI, Kumar V, et al. Effect of Immediate Dentin Sealing on Polymerization of Elastomeric Materials: An Ex Vivo Randomized Controlled Trial. Int J Clin Pediatr Dent 2019;12(4):288–292.