APPLICATION OF CORONA DESTRUCTION AS A METHOD TO CONTROL VOLATILEORGANIC COMPOUNDS

EPA Science Inventory

The paper discusses EPA tests of two types of corona reactors. nemakes use of a bed of ferroelectric pellets across which analternating current electric field is impressed. he otherdevelops corona between two electrodes that have been energized bya fast rise time (nanosecond rang...

The shape of novel objects contributes to shared impressions.

PubMed

Kurosu, Aaron; Todorov, Alexander

2017-11-01

How do people share impressions of novel objects, and is this even possible? We tested whether the shape of novel 3-D objects can lead to similar impressions across people. To do this, we introduced a technique for manipulating highly complex shapes and measured four types of evaluative impressions (approachable, dangerous, beautiful, likable). Because relatively little is understood regarding how people form impressions of novel objects, we first sought to confirm the reliability of this behavior by examining how similar impressions are for an individual asked to re-evaluate the stimuli (i.e., impression consistency). To situate the magnitude of reliability, we compared novel objects to faces-familiar and extensively studied stimuli. Impression consistency was always present for both types of stimuli and comparable across all evaluations. Second, and more importantly, we tested how similar impressions are across people (i.e., impression consensus). Impression consensus was always present for faces, but not always for novel objects. In Study 2 we examined a greater diversity of shapes and replicated the findings of Study 1 for novel objects. The findings suggest that impression consensus for novel objects only emerges when certain types of shapes and evaluations map together. When such mapping is possible, impressions are isomorphic with the parametrized shapes.

Influence of impression technique and material on the accuracy of multiple implant impressions.

PubMed

Wöstmann, Bernd; Rehmann, Peter; Balkenhol, Markus

2008-01-01

This study aimed to analyze the influence of impression technique (pick-up versus reposition) and material on the accuracy of the working cast. Sixty impressions were made with 3 materials from a master cast with 4 XiVE implants. The changes in the implant axis direction, rotation, and 3-dimensional shift were assessed. The pick-up technique showed significantly (P < .05, U test) lower values for axis direction and 3D shift but higher values for rotation than the reposition technique. The differences between the materials were not significant (P > .05, H test). It can be concluded that the impression technique-in contrast to the impression material-has a significant influence on transfer accuracy.

First Impressions From Faces.

PubMed

Zebrowitz, Leslie A

2017-06-01

Although cultural wisdom warns 'don't judge a book by its cover,' we seem unable to inhibit this tendency even though it can produce inaccurate impressions of people's psychological traits and has significant social consequences. One explanation for this paradox is that first impressions of faces overgeneralize our adaptive impressions of categories of people that those faces resemble (including babies, familiar or unfamiliar people, unfit people, emotional people). Research testing these 'overgeneralization' hypotheses elucidates why we form first impressions from faces, what impressions we form, and what cues influence these impressions. This article focuses on commonalities in impressions across diverse perceivers. However, brief attention is given to individual differences in impressions and impression accuracy.

Dimensional Accuracy of Hydrophilic and Hydrophobic VPS Impression Materials Using Different Impression Techniques - An Invitro Study

PubMed Central

Pilla, Ajai; Pathipaka, Suman

2016-01-01

Introduction The dimensional stability of the impression material could have an influence on the accuracy of the final restoration. Vinyl Polysiloxane Impression materials (VPS) are most frequently used as the impression material in fixed prosthodontics. As VPS is hydrophobic when it is poured with gypsum products, manufacturers added intrinsic surfactants and marketed as hydrophilic VPS. These hydrophilic VPS have shown increased wettability with gypsum slurries. VPS are available in different viscosities ranging from very low to very high for usage under different impression techniques. Aim To compare the dimensional accuracy of hydrophilic VPS and hydrophobic VPS using monophase, one step and two step putty wash impression techniques. Materials and Methods To test the dimensional accuracy of the impression materials a stainless steel die was fabricated as prescribed by ADA specification no. 19 for elastomeric impression materials. A total of 60 impressions were made. The materials were divided into two groups, Group1 hydrophilic VPS (Aquasil) and Group 2 hydrophobic VPS (Variotime). These were further divided into three subgroups A, B, C for monophase, one-step and two-step putty wash technique with 10 samples in each subgroup. The dimensional accuracy of the impressions was evaluated after 24 hours using vertical profile projector with lens magnification range of 20X-125X illumination. The study was analyzed through one-way ANOVA, post-hoc Tukey HSD test and unpaired t-test for mean comparison between groups. Results Results showed that the three different impression techniques (monophase, 1-step, 2-step putty wash techniques) did cause significant change in dimensional accuracy between hydrophilic VPS and hydrophobic VPS impression materials. One-way ANOVA disclosed, mean dimensional change and SD for hydrophilic VPS varied between 0.56% and 0.16%, which were low, suggesting hydrophilic VPS was satisfactory with all three impression techniques. However, mean dimensional change and SD for hydrophobic VPS were much higher with monophase, mere increase for 1-step and 2-step, than the standard steel die (p<0.05). Unpaired t-test displayed that hydrophilic VPS judged satisfactory compared to hydrophobic VPS among 1-step and 2-step impression technique. Conclusion Within the limitations of this study, it can be concluded that hydrophilic Vinyl polysiloxane was more dimensionally accurate than hydrophobic Vinyl polysiloxane using monophase, one step and two step putty wash impression techniques under moist conditions. PMID:27042587

Digital versus conventional implant impressions for edentulous patients: accuracy outcomes.

PubMed

Papaspyridakos, Panos; Gallucci, German O; Chen, Chun-Jung; Hanssen, Stijn; Naert, Ignace; Vandenberghe, Bart

2016-04-01

To compare the accuracy of digital and conventional impression techniques for completely edentulous patients and to determine the effect of different variables on the accuracy outcomes. A stone cast of an edentulous mandible with five implants was fabricated to serve as master cast (control) for both implant- and abutment-level impressions. Digital impressions (n = 10) were taken with an intraoral optical scanner (TRIOS, 3shape, Denmark) after connecting polymer scan bodies. For the conventional polyether impressions of the master cast, a splinted and a non-splinted technique were used for implant-level and abutment-level impressions (4 cast groups, n = 10 each). Master casts and conventional impression casts were digitized with an extraoral high-resolution scanner (IScan D103i, Imetric, Courgenay, Switzerland) to obtain digital volumes. Standard tessellation language (STL) datasets from the five groups of digital and conventional impressions were superimposed with the STL dataset from the master cast to assess the 3D (global) deviations. To compare the master cast with digital and conventional impressions at the implant level, analysis of variance (ANOVA) and Scheffe's post hoc test was used, while Wilcoxon's rank-sum test was used for testing the difference between abutment-level conventional impressions. Significant 3D deviations (P < 0.001) were found between Group II (non-splinted, implant level) and control. No significant differences were found between Groups I (splinted, implant level), III (digital, implant level), IV (splinted, abutment level), and V (non-splinted, abutment level) compared with the control. Implant angulation up to 15° did not affect the 3D accuracy of implant impressions (P > 0.001). Digital implant impressions are as accurate as conventional implant impressions. The splinted, implant-level impression technique is more accurate than the non-splinted one for completely edentulous patients, whereas there was no difference in the accuracy at the abutment level. The implant angulation up to 15° did not affect the accuracy of implant impressions. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Accuracy of impressions with different impression materials in angulated implants.

PubMed

Reddy, S; Prasad, K; Vakil, H; Jain, A; Chowdhary, R

2013-01-01

To evaluate the dimensional accuracy of the resultant (duplicative) casts made from two different impression materials (polyvinyl siloxane and polyether) in parallel and angulated implants. Three definitive master casts (control groups) were fabricated in dental stone with three implants, placed at equi-distance. In first group (control), all three implants were placed parallel to each other and perpendicular to the plane of the cast. In the second and third group (control), all three implants were placed at 10° and 15 o angulation respectively to the long axis of the cast, tilting towards the centre. Impressions were made with polyvinyl siloxane and polyether impression materials in a special tray, using a open tray impression technique from the master casts. These impressions were poured to obtain test casts. Three reference distances were evaluated on each test cast by using a profile projector and compared with control groups to determine the effect of combined interaction of implant angulation and impression materials on the accuracy of implant resultant cast. Statistical analysis revealed no significant difference in dimensional accuracy of the resultant casts made from two different impression materials (polyvinyl siloxane and polyether) by closed tray impression technique in parallel and angulated implants. On the basis of the results of this study, the use of both the impression materials i.e., polyether and polyvinyl siloxane impression is recommended for impression making in parallel as well as angulated implants.

First Impressions From Faces

PubMed Central

Zebrowitz, Leslie A

2016-01-01

Although cultural wisdom warns ‘don’t judge a book by its cover,’ we seem unable to inhibit this tendency even though it can produce inaccurate impressions of people’s psychological traits and has significant social consequences. One explanation for this paradox is that first impressions of faces overgeneralize our adaptive impressions of categories of people that those faces resemble (including babies, familiar or unfamiliar people, unfit people, emotional people). Research testing these ‘overgeneralization’ hypotheses elucidates why we form first impressions from faces, what impressions we form, and what cues influence these impressions. This article focuses on commonalities in impressions across diverse perceivers. However, brief attention is given to individual differences in impressions and impression accuracy. PMID:28630532

Biased relevance filtering in the auditory system: A test of confidence-weighted first-impressions.

PubMed

Mullens, D; Winkler, I; Damaso, K; Heathcote, A; Whitson, L; Provost, A; Todd, J

2016-03-01

Although first-impressions are known to impact decision-making and to have prolonged effects on reasoning, it is less well known that the same type of rapidly formed assumptions can explain biases in automatic relevance filtering outside of deliberate behavior. This paper features two studies in which participants have been asked to ignore sequences of sound while focusing attention on a silent movie. The sequences consisted of blocks, each with a high-probability repetition interrupted by rare acoustic deviations (i.e., a sound of different pitch or duration). The probabilities of the two different sounds alternated across the concatenated blocks within the sequence (i.e., short-to-long and long-to-short). The sound probabilities are rapidly and automatically learned for each block and a perceptual inference is formed predicting the most likely characteristics of the upcoming sound. Deviations elicit a prediction-error signal known as mismatch negativity (MMN). Computational models of MMN generally assume that its elicitation is governed by transition statistics that define what sound attributes are most likely to follow the current sound. MMN amplitude reflects prediction confidence, which is derived from the stability of the current transition statistics. However, our prior research showed that MMN amplitude is modulated by a strong first-impression bias that outweighs transition statistics. Here we test the hypothesis that this bias can be attributed to assumptions about predictable vs. unpredictable nature of each tone within the first encountered context, which is weighted by the stability of that context. The results of Study 1 show that this bias is initially prevented if there is no 1:1 mapping between sound attributes and probability, but it returns once the auditory system determines which properties provide the highest predictive value. The results of Study 2 show that confidence in the first-impression bias drops if assumptions about the temporal stability of the transition-statistics are violated. Both studies provide compelling evidence that the auditory system extrapolates patterns on multiple timescales to adjust its response to prediction-errors, while profoundly distorting the effects of transition-statistics by the assumptions formed on the basis of first-impressions. Copyright © 2016 Elsevier B.V. All rights reserved.

A Comparative Analysis of Master Casts Obtained using Different Surface Treatments on Impression Copings for Single Tooth Implant Replacement -An In vitro Study.

PubMed

Abrol, Surbhi; Nagpal, Archana; Kaur, Rupandeep; Verma, Ramit; Katna, Vishal; Gupt, Parikshit

2017-08-01

Minor rotation of impression coping secured in the impression is an avoidable error that needs to be minimized to ensure precise positioning of implant analog in master cast. The aim of the study was to compare the precision in obtaining master casts by improving the stability of impression copings in the impression with the use of tray adhesive along various surface treatments to increase surface area and by mechanical locking. A total of 60 samples were made (15 samples for each group). A total of 15 samples for Group I were prepared with untreated impression copings, 15 samples for Group II with impression copings treated and modified by application of tray adhesive only. Group III includes 15 samples which were fabricated with impression copings modified by making four vertical grooves on surface of impression coping and coated with adhesive. Group IV had 15 samples which were fabricated with impression copings sandblasted with 50 μm aluminum oxide powder and coated with adhesive. Profile projector was used to evaluate the rotational accuracy of the implant analogs by comparing Molar Implant Angle (MIA) and Premolar Implant Angle (PIA) of test samples with reference model. One-way ANOVA and Student t-test were used to analyze the data. One-way ANOVA didn't show any significant differences for both MIA and PIA between the Groups I, II, III and IV. Student's unpaired t-test revealed no significant difference in the mean MIA and mean PIA. Conclusion: Though results were statistically non-significant, all types of surface treatments of the impression copings showed more accurate transfer than those with no treatment. Sandblasted and adhesive coated impression copings showed minimum amount of rotation followed by those with vertical slots and adhesive coated impression copings.

Sharing Rare Attitudes Attracts.

PubMed

Alves, Hans

2018-04-01

People like others who share their attitudes. Online dating platforms as well as other social media platforms regularly rely on the social bonding power of their users' shared attitudes. However, little is known about moderating variables. In the present work, I argue that sharing rare compared with sharing common attitudes should evoke stronger interpersonal attraction among people. In five studies, I tested this prediction for the case of shared interests from different domains. I found converging evidence that people's rare compared with their common interests are especially potent to elicit interpersonal attraction. I discuss the current framework's theoretical implications for impression formation and impression management as well as its practical implications for improving online dating services.

Accuracy of Different Implant Impression Techniques: Evaluation of New Tray Design Concept.

PubMed

Liu, David Yu; Cader, Fathima Nashmie; Abduo, Jaafar; Palamara, Joseph

2017-12-29

To evaluate implant impression accuracy with a new tray design concept in comparison to nonsplinted and splinted impression techniques for a 2-implant situation. A reference bar titanium framework was fabricated to fit on 2 parallel implants. The framework was used to generate a resin master model with 2 implants that fit precisely against the framework. Three impression techniques were evaluated: (1) nonsplinted, (2) splinted, and (3) nonsplinted with modified tray impressions. All the trays were fabricated from light-cured acrylic resin material with openings that corresponded to the implant impression copings. Ten impressions were taken for each technique using poly(vinyl siloxane) impression material. The impressions were poured with type IV dental stone to generate the test casts. A rosette strain gauge was bonded to the middle of the framework. As the framework retaining screws were tightened on each test cast, the developed strains were recorded until the completion of the tightening to 35 Ncm. The generated strains of the rosette strain gauge were used to calculate the maximum principal strain. A statistically significant difference was observed among the different impression techniques. The modified tray design impression technique was associated with the least framework strains, which indicates greater accuracy compared with the other techniques. There was no significant difference between the splinted and the nonsplinted impression techniques. The new tray design concept appeared to produce more accurate implant impressions than the other techniques. Despite the statistical difference among the impression techniques, the clinical significance of this difference is yet to be determined. © 2017 by the American College of Prosthodontists.

Soft tissue-preserving computer-aided impression: a novel concept using ultrasonic 3D-scanning.

PubMed

Vollborn, Thorsten; Habor, Daniel; Pekam, Fabrice Chuembou; Heger, Stefan; Marotti, Juliana; Reich, Sven; Wolfart, Stefan; Tinschert, Joachim; Radermacher, Klaus

2014-01-01

Subgingival preparations are often affected by blood and saliva during impression taking, regardless of whether one is using compound impression techniques or intraoral digital scanning methods. The latter are currently based on optical principles and therefore also need clean and dry surfaces. In contrast, ultrasonic waves are able to non-invasively penetrate gingiva, saliva, and blood, leading to decisive advantages, as cleaning and drying of the oral cavity becomes unnecessary. In addition, the application of ultrasound may facilitate the detection of subgingival structures without invasive manipulation, thereby reducing the risk of secondary infection and treatment time, and increasing patient comfort. Ultrasound devices commonly available for medical application and for the testing of materials are only suitable to a limited extent, as their resolution, precision, and design do not fulfill the requirements for intraoral scanning. The aim of this article is to describe the development of a novel ultrasound technology that enables soft tissue-preserving digital impressions of preparations for the CAD/CAM-based production of dental prostheses. The concept and development of the high-resolution ultrasound technique and the corresponding intraoral scanning system, as well as the integration into the CAD/CAM process chain, is presented.

How the adoption of impression management goals alters impression formation.

PubMed

Gibson, Bryan; Poposki, Elizabeth M

2010-11-01

Five experiments (N = 390) tested the hypothesis that adopting an impression management goal leads the impression manager to view an interaction partner as having less of the trait he or she is attempting to express. This hypothesis was confirmed for the impression management goals of appearing introverted, extraverted, smart, confident, and happy. Experiment 2 shows that adoption of the impression goal could alter judgments even when participants could not act on the goal. Experiment 3 provides evidence that adopting an impression management goal prompted a comparison mind-set and that this comparison mind-set activation mediated target judgments. Experiment 4 rules out a potential alternative explanation and provides more direct evidence that comparison of the impression manager's self-concept mediates the impression of the target. Experiment 5 eliminates a potential confound and extends the effect to another impression goal. These experiments highlight the dynamic interplay between impression management and impression formation.

Students’ Impression towards Science Virtual Test (SVT) on Digestive System Topic

NASA Astrophysics Data System (ADS)

Mahfira, C.; Sanjaya, Y.; Rusyati, L.

2018-05-01

During the past few years, technology has significantly support the improvements in assessment.Computer-based test (CBT) comes up as a new type of assessment which offers many benefits. The implementation of computer-based test in term of students’ perspective gives rise to numbers of mixed reactions. Students’ impression is one of the essential things for the implementation of SVT. The purpose of this study was to investigate the impression of students toward SVT. The method used in this research was descriptive method. The participant was 98 students from Junior High School “X” in East Bandung. Students’ impression questionnaire was used as the instrument. There are four aspects tested in this instrument which are students’ experience, technical activity, preference and media of SVT. The result shows that SVT generally gives positive impression to students. Students have a positive experience and did not encounter significant problem when implementing SVT. Students prefer to use SVT and students think the media of SVT is already good.

An evaluation of student and clinician perception of digital and conventional implant impressions.

PubMed

Lee, Sang J; Macarthur, Robert X; Gallucci, German O

2013-11-01

The accuracy and efficiency of digital implant impressions should match conventional impressions. Comparisons should be made with clinically relevant data. The purpose of this study was to evaluate the difficulty level and operator's perception between dental students and experienced clinicians when making digital and conventional implant impressions. Thirty experienced dental professionals and 30 second-year dental students made conventional and digital impressions of a single implant model. A visual analog scale (VAS) and multiple-choice questionnaires were used to assess the participant's perception of difficulty, preference, and effectiveness. Wilcoxon signed-rank test within the groups and Wilcoxon rank-sum test between the groups were used for statistical analysis (α=.05). On a 0 to 100 VAS, the student group scored a mean difficulty level of 43.1 (±18.5) for the conventional impression technique and 30.6 (±17.6) for the digital impression technique (P=.006). The clinician group scored a mean (standard deviation) difficulty level of 30.9 (±19.6) for conventional impressions and 36.5 (±20.6) for digital impressions (P=.280). Comparison between groups showed a mean difficulty level with the conventional impression technique significantly higher in the student group (P=.030). The digital impression was not significantly different between the groups (P=.228). Sixty percent of the students preferred the digital impression and 7% the conventional impression; 33% expressed no preference. In the clinician group, 33% preferred the digital impression and 37% the conventional impression; 30% had no preference. Seventy-seven percent of the student group felt most effective with digital impressions, 10% with conventional impressions, and 13% with either technique, whereas 40% of the clinician group chose the digital impression as the most effective technique, 53% the conventional impression, and 7% either technique. The conventional impression was more difficult to perform for the student group than the clinician group; however, the difficulty level of the digital impression was the same in both groups. It was also determined that the student group preferred the digital impression as the most efficient impression technique, and the clinician group had an even distribution in the choice of preferred and efficient impression techniques. Copyright © 2013 Editorial Council for the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Effect of mixing techniques on bacterial attachment and disinfection time of polyether impression material

PubMed Central

Guler, Umut; Budak, Yasemin; Ruh, Emrah; Ocal, Yesim; Canay, Senay; Akyon, Yakut

2013-01-01

Objective: The aim of this study was 2-fold. The first aim was to evaluate the effects of mixing technique (hand-mixing or auto-mixing) on bacterial attachment to polyether impression materials. The second aim was to determine whether bacterial attachment to these materials was affected by length of exposure to disinfection solutions. Materials and Methods: Polyether impression material samples (n = 144) were prepared by hand-mixing or auto-mixing. Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa were used in testing. After incubation, the bacterial colonies were counted and then disinfectant solution was applied. The effect of disinfection solution was evaluated just after the polymerization of impression material and 30 min after polymerization. Differences in adherence of bacteria to the samples prepared by hand-mixing and to those prepared by auto-mixing were assessed by Kruskal-Wallis and Mann-Whitney U-tests. For evaluating the efficiency of the disinfectant, Kruskal-Wallis multiple comparisons test was used. Results: E. coli counts were higher in hand-mixed materials (P < 0.05); no other statistically significant differences were found between hand- and auto-mixed materials. According to the Kruskal-Wallis test, significant differences were found between the disinfection procedures (Z > 2.394). Conclusion: The methods used for mixing polyether impression material did not affect bacterial attachment to impression surfaces. In contrast, the disinfection procedure greatly affects decontamination of the impression surface. PMID:24966729

Effect of mixing techniques on bacterial attachment and disinfection time of polyether impression material.

PubMed

Guler, Umut; Budak, Yasemin; Ruh, Emrah; Ocal, Yesim; Canay, Senay; Akyon, Yakut

2013-09-01

The aim of this study was 2-fold. The first aim was to evaluate the effects of mixing technique (hand-mixing or auto-mixing) on bacterial attachment to polyether impression materials. The second aim was to determine whether bacterial attachment to these materials was affected by length of exposure to disinfection solutions. Polyether impression material samples (n = 144) were prepared by hand-mixing or auto-mixing. Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa were used in testing. After incubation, the bacterial colonies were counted and then disinfectant solution was applied. The effect of disinfection solution was evaluated just after the polymerization of impression material and 30 min after polymerization. Differences in adherence of bacteria to the samples prepared by hand-mixing and to those prepared by auto-mixing were assessed by Kruskal-Wallis and Mann-Whitney U-tests. For evaluating the efficiency of the disinfectant, Kruskal-Wallis multiple comparisons test was used. E. coli counts were higher in hand-mixed materials (P < 0.05); no other statistically significant differences were found between hand- and auto-mixed materials. According to the Kruskal-Wallis test, significant differences were found between the disinfection procedures (Z > 2.394). The methods used for mixing polyether impression material did not affect bacterial attachment to impression surfaces. In contrast, the disinfection procedure greatly affects decontamination of the impression surface.

Sometimes Happy People Focus on the Trees and Sad People Focus on the Forest: Context-Dependent Effects of Mood in Impression Formation

PubMed Central

Hunsinger, Matthew; Isbell, Linda M.; Clore, Gerald L.

2014-01-01

Research indicates that affect influences whether people focus on categorical or behavioral information during impression formation. One explanation is that affect confers its value on whatever cognitive inclinations are most accessible in a given situation. Three studies tested this malleable mood effects hypothesis, predicting that happy moods should maintain and unhappy moods should inhibit situationally dominant thinking styles. Participants completed an impression formation task that included categorical and behavioral information. Consistent with the proposed hypothesis, no fixed relation between mood and processing emerged. Whether happy moods led to judgments reflecting category-level or behavior-level information depended on whether participants were led to focus on the their immediate psychological state (i.e., current affective experience; Studies 1 and 2) or physical environment (i.e., an unexpected odor; Study 3). Consistent with research on socially situated cognition, these results demonstrate that the same affective state can trigger entirely different thinking styles depending on the context. PMID:21957087

Intraoral 3D Scanning or Dental Impressions for the Assessment of Dental Arch Relationships in Cleft Care: Which is Superior?

PubMed

Chalmers, E V; McIntyre, G T; Wang, W; Gillgrass, T; Martin, C B; Mossey, P A

2016-09-01

This study was undertaken to evaluate intraoral 3D scans for assessing dental arch relationships and obtain patient/parent perceptions of impressions and intraoral 3D scanning. Forty-three subjects with nonsyndromic unilateral cleft lip and palate (UCLP) had impressions taken for plaster models. These and the teeth were scanned using the R700 Orthodontic Study Model Scanner and Trios® Digital Impressions Scanner (3Shape A/S, Copenhagen, Denmark) to create indirect and direct digital models. All model formats were scored by three observers on two occasions using the GOSLON and modified Huddart Bodenham (MHB) indices. Participants and parents scored their perceptions of impressions and scanning from 1 (very good) to 5 (very bad). Intra- and interexaminer reliability were tested using GOSLON and MHB data (Cronbach's Alpha >0.9). Bland and Altman plots were created for MHB data, with each model medium (one-sample t tests, P < .05) and questionnaire data (Wilcoxon signed ranks P < .05) tested. Intra- and interexaminer reliability (>0.9) were good for all formats with the direct digital models having the lowest interexaminer differences. Participants had higher ratings for scanning comfort (84.8%) than impressions (44.2%) (P < .05) and for scanning time (56.6%) than impressions (51.2%) (P > .05). None disliked scanning, but 16.3% disliked impressions. Data for parents and children positively correlated (P < .05). Reliability of scoring dental arch relationships using intraoral 3D scans was superior to indirect digital and to plaster models; Subjects with UCLP preferred intra-oral 3D scanning to dental impressions, mirrored by parents/carers; This study supports the replacement of conventional impressions with intra-oral 3D scans in longitudinal evaluations of the outcomes of cleft care.

Three-dimensional accuracy of plastic transfer impression copings for three implant systems.

PubMed

Teo, Juin Wei; Tan, Keson B; Nicholls, Jack I; Wong, Keng Mun; Uy, Joanne

2014-01-01

The purpose of this study was to compare the three-dimensional accuracy of indirect plastic impression copings and direct implant-level impression copings from three implant systems (Nobel Biocare [NB], Biomet 3i [3i], and Straumann [STR]) at three interimplant buccolingual angulations (0, 8, and 15 degrees). Two-implant master models were used to simulate a three-unit implant fixed partial denture. Test models were made from Impregum impressions using direct implant-level impression copings (DR). Abutments were then connected to the master models for impressions using the plastic impression copings (INDR) at three different angulations for a total of 18 test groups (n = 5 in each group). A coordinate measuring machine was used to measure linear distortions, three-dimensional (3D) distortions, angular distortions, and absolute angular distortions between the master and test models. Three-way analysis of variance showed that the implant system had a significant effect on 3D distortions and absolute angular distortions in the x- and y-axes. Interimplant angulation had a significant effect on 3D distortions and absolute angular distortions in the y-axis. Impression technique had a significant effect on absolute angular distortions in the y-axis. With DR, the NB and 3i systems were not significantly different. With INDR, 3i appeared to have less distortion than the other systems. Interimplant angulations did not significantly affect the accuracy of NBDR, 3iINDR, and STRINDR. The accuracy of INDR and DR was comparable at all interimplant angulations for 3i and STR. For NB, INDR was comparable to DR at 0 and 8 degrees but was less accurate at 15 degrees. Three-dimensional accuracy of implant impressions varied with implant system, interimplant angulation, and impression technique.

Examining the Moderating Effect of Appearance Impression Motivation on the Relationship between Perceived Physical Appearance and Social Physique Anxiety

ERIC Educational Resources Information Center

Amorose, Anthony J.; Hollembeak, Jill

2005-01-01

Despite the conceptual importance of impression motivation in predicting social anxiety (Leary & Kowalski, 1995; Schlenker & Leary, 1982), no research has tested the link between impression motivation specifically regarding one's physical appearance (appearance impression motivation, or AIM) and social physique anxiety (SPA). The purpose of this…

How accurate are medical oncologists' impressions of management of metastatic colorectal cancer in Australia?

PubMed

Au, Lewis; Turner, Natalie; Wong, Hui-Li; Field, Kathryn; Lee, Belinda; Boadle, David; Cooray, Prasad; Karikios, Deme; Kosmider, Suzanne; Lipton, Lara; Nott, Louise; Parente, Phillip; Tie, Jeanne; Tran, Ben; Wong, Rachel; Yip, Desmond; Shapiro, Jeremy; Gibbs, Peter

2018-04-01

Current efforts to understand patient management in clinical practice are largely based on clinician surveys with uncertain reliability. The TRACC (Treatment of Recurrent and Advanced Colorectal Cancer) database is a multisite registry collecting comprehensive treatment and outcome data on consecutive metastatic colorectal cancer (mCRC) patients at multiple sites across Australia. This study aims to determine the accuracy of oncologists' impressions of real-word practice by comparing clinicians' estimates to data captured by TRACC. Nineteen medical oncologists from nine hospitals contributing data to TRACC completed a 34-question survey regarding their impression of the management and outcomes of mCRC at their own practice and other hospitals contributing to the database. Responses were then compared with TRACC data to determine how closely their impressions reflected actual practice. Data on 1300 patients with mCRC were available. Median clinician estimated frequency of KRAS testing within 6 months of diagnosis was 80% (range: 20-100%); the TRACC documented rate was 43%. Clinicians generally overestimated the rates of first-line treatment, particularly in patients over 75 years. Estimate for bevacizumab in first line was 60% (35-80%) versus 49% in TRACC. Estimated rate for liver resection varied substantially (5-35%), and the estimated median (27%) was inconsistent with the TRACC rate (12%). Oncologists generally felt their practice was similar to other hospitals. Oncologists' estimates of current clinical practice varied and were discordant with the TRACC database, often with a tendency to overestimate interventions. Clinician surveys alone do not reliably capture contemporary clinical practices in mCRC. © 2017 John Wiley & Sons Australia, Ltd.

Lifting bloody footwear impressions using alginate casts followed by chemical enhancement.

PubMed

Wiesner, Sarena; Izraeli, Elad; Shor, Yaron; Domb, Avi

2013-05-01

A method for lifting bloody footwear impressions using alginate casts and enhancing the lifted impressions with amido black is presented. On rough or dark substrates, background interferences may conceal significant details of footwear impressions. Illumination with alternative light sources and chemically enhancing the bloody footwear impressions may reveal additional details, but sometimes, lifting footwear impressions prior to enhancing is the only way to expose hidden details (by using blood reagents not adequate on the original). Several cast formulations were tested for lifting the footwear impressions. The best results were achieved using Aroma fine®. Enhancement of the footwear impressions was attempted with several reagents prior to lifting, during the casting process, and on the lifted footwear impressions. Applying amido black to footwear impressions lifted with alginate produced the sharpest and most detailed footwear impressions. Alginate castings followed by chemical enhancement with amido black may produce high-quality footwear impressions for comparison. © 2013 American Academy of Forensic Sciences.

Sulcus reproduction with elastomeric impression materials: a new in vitro testing method.

PubMed

Finger, Werner J; Kurokawa, Rie; Takahashi, Hidekazu; Komatsu, Masashi

2008-12-01

Aim of this study was to investigate the depth reproduction of differently wide sulci with elastomeric impression materials by single- and double-mix techniques using a tooth and sulcus model, simulating clinical conditions. Impressions with one vinyl polysiloxane (VPS; FLE), two polyethers (PE; IMP and P2), and one hybrid VPS/PE elastomer (FUS) were taken from a truncated steel cone with a circumferential 2 mm deep sulcus, 50, 100 or 200 microm wide. The "root surface" was in steel and the "periodontal tissue" in reversible hydrocolloid. Single-mix impressions were taken with light-body (L) or monophase (M) pastes, double-mix impressions with L as syringe and M or heavy-body (H) as tray materials (n=8). Sulcus reproduction was determined by 3D laser topography of impressions at eight locations, 45 degrees apart. Statistical data analysis by ANOVA and multiple comparison tests (p<0.05). For 200 microm wide sulci, significant differences were found between impression materials only: FLE=IMP>FUS=P2. At 50 and 100 microm width, significant differences were found between materials (IMP>FUS=FLE>P2) and techniques (L+H=L+M>M>L). The sulcus model is considered useful for screening evaluation of elastomeric impression materials ability to reproduce narrow sulci. All tested materials and techniques reproduced 200 microm wide sulci to almost nominal depth. Irrespective of the impression technique used, IMP showed the best penetration ability in 50 and 100 microm sulci. Double-mix techniques are more suitable to reproduce narrow sulci than single-mix techniques.

Intraoral scanners in dentistry: a review of the current literature.

PubMed

Mangano, Francesco; Gandolfi, Andrea; Luongo, Giuseppe; Logozzo, Silvia

2017-12-12

Intraoral scanners (IOS) are devices for capturing direct optical impressions in dentistry. The purpose of this narrative review on the use of IOS was to: (1) identify the advantages/disadvantages of using optical impressions compared to conventional impressions; (2) investigate if optical impressions are as accurate as conventional impressions; (3) evaluate the differences between the IOS currently available commercially; (4) determine the current clinical applications/limitations in the use of IOS. Electronic database searches were performed using specific keywords and MeSH terms. The searches were confined to full-text articles written in English and published in peer-reviewed journals between January 2007 and June 2017. One hundred thirty-two studies were included in the present review; among them, 20 were previous literature reviews, 78 were in vivo clinical studies (6 randomized controlled/crossover trials, 31 controlled/comparative studies; 24 cohort studies/case series; 17 case reports) and 34 were in vitro comparative studies. Optical impressions reduce patient discomfort; IOS are time-efficient and simplify clinical procedures for the dentist, eliminating plaster models and allowing better communication with the dental technician and with patients; however, with IOS, it can be difficult to detect deep margin lines in prepared teeth and/or in case of bleeding, there is a learning curve, and there are purchasing and managing costs. The current IOS are sufficiently accurate for capturing impressions for fabricating a whole series of prosthetic restorations (inlays/onlays, copings and frameworks, single crowns and fixed partial dentures) on both natural teeth and implants; in addition, they can be used for smile design, and to fabricate posts and cores, removable partial prostheses and obturators. The literature to date does not support the use of IOS in long-span restorations with natural teeth or implants. Finally, IOS can be integrated in implant dentistry for guided surgery and in orthodontics for fabricating aligners and custom-made devices.

Determining post-test risk in a national sample of stress nuclear myocardial perfusion imaging reports: Implications for natural language processing tools.

PubMed

Levy, Andrew E; Shah, Nishant R; Matheny, Michael E; Reeves, Ruth M; Gobbel, Glenn T; Bradley, Steven M

2018-04-25

Reporting standards promote clarity and consistency of stress myocardial perfusion imaging (MPI) reports, but do not require an assessment of post-test risk. Natural Language Processing (NLP) tools could potentially help estimate this risk, yet it is unknown whether reports contain adequate descriptive data to use NLP. Among VA patients who underwent stress MPI and coronary angiography between January 1, 2009 and December 31, 2011, 99 stress test reports were randomly selected for analysis. Two reviewers independently categorized each report for the presence of critical data elements essential to describing post-test ischemic risk. Few stress MPI reports provided a formal assessment of post-test risk within the impression section (3%) or the entire document (4%). In most cases, risk was determinable by combining critical data elements (74% impression, 98% whole). If ischemic risk was not determinable (25% impression, 2% whole), inadequate description of systolic function (9% impression, 1% whole) and inadequate description of ischemia (5% impression, 1% whole) were most commonly implicated. Post-test ischemic risk was determinable but rarely reported in this sample of stress MPI reports. This supports the potential use of NLP to help clarify risk. Further study of NLP in this context is needed.

Qualitative computer aided evaluation of dental impressions in vivo.

PubMed

Luthardt, Ralph G; Koch, Rainer; Rudolph, Heike; Walter, Michael H

2006-01-01

Clinical investigations dealing with the precision of different impression techniques are rare. Objective of the present study was to develop and evaluate a procedure for the qualitative analysis of the three-dimensional impression precision based on an established in-vitro procedure. The zero hypothesis to be tested was that the precision of impressions does not differ depending on the impression technique used (single-step, monophase and two-step-techniques) and on clinical variables. Digital surface data of patient's teeth prepared for crowns were gathered from standardized manufactured master casts after impressions with three different techniques were taken in a randomized order. Data-sets were analyzed for each patient in comparison with the one-step impression chosen as the reference. The qualitative analysis was limited to data-points within the 99.5%-range. Based on the color-coded representation areas with maximum deviations were determined (preparation margin and the mantle and occlusal surface). To qualitatively analyze the precision of the impression techniques, the hypothesis was tested in linear models for repeated measures factors (p < 0.05). For the positive 99.5% deviations no variables with significant influence were determined in the statistical analysis. In contrast, the impression technique and the position of the preparation margin significantly influenced the negative 99.5% deviations. The influence of clinical parameter on the deviations between impression techniques can be determined reliably using the 99.5 percentile of the deviations. An analysis regarding the areas with maximum deviations showed high clinical relevance. The preparation margin was pointed out as the weak spot of impression taking.

Application of gamma-ray radiography and gravimetric measurements after accelerated corrosion tests of steel embedded in mortar

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duffó, Gustavo, E-mail: duffo@cnea.gov.ar; Consejo Nacional de Investigaciones Científicas y Técnicas; Universidad Nacional de San Martín, Av. Gral. Paz 1499, 1650 San Martín, Buenos Aires

2015-08-15

The accelerated corrosion by the impressed current technique is widely used in studies of concrete durability since it has the advantage that tests can be carried out within reasonable periods of time. In the present work the relationship between the applied current density and the resulting damage on the reinforcing steel, by applying optical microscopy, scanning electron microscopy, gamma-ray radiography and gravimetric measurements, was studied by means of the implementation of accelerated corrosion tests on reinforced mortar. The results show that the efficiency of the applied current is between 1 and 77%, regardless of the applied current density, the water/cementmore » ratio and the mortar cover depth of the specimens. The results show the applicability of the gamma-ray radiography technique to detect localized corrosion of steel rebars in laboratory specimens.« less

Evaluation of the three-dimensional accuracy of implant impression techniques in two simulated clinical conditions by optical scanning.

PubMed

Sabouhi, Mahmoud; Bajoghli, Farshad; Abolhasani, Majid

2015-01-01

The success of an implant-supported prosthesis is dependent on the passive fit of its framework fabricated on a precise cast. The aim of this in vitro study was to digitally compare the three-dimensional accuracy of implant impression techniques in partially and completely edentulous conditions. The master model simulated two clinical conditions. The first condition was a partially edentulous mandibular arch with an anterior edentulous space (D condition). Two implant analogs were inserted in bilateral canine sites. After elimination of the teeth, the model was converted to a completely edentulous condition (E condition). Three different impression techniques were performed (open splinted [OS], open unsplinted [OU], closed [C]) for each condition. Six groups of casts (DOS, DOU, DC, EOS, EOU, EC) (n = 8), totaling 48 casts, were made. Two scan bodies were secured onto the master edentulous model and onto each test cast and digitized by an optical scanning system. The related scans were superimposed, and the mean discrepancy for each cast was determined. The statistical analysis showed no significant difference in the accuracy of casts as a function of model status (P = .78, analysis of variance [ANOVA] test), impression technique (P = .57, ANOVA test), or as the combination of both (P = .29, ANOVA test). The distribution of data was normal (Kolmogorov-Smirnov test). Model status (dentate or edentulous) and impression technique did not influence the precision of the casts. There is no difference among any of the impression techniques in either simulated clinical condition.

Establishing versus preserving impressions: Predicting success in the multiple audience problem.

PubMed

Nichols, Austin Lee; Cottrell, Catherine A

2015-12-01

People sometimes seek to convey discrepant impressions of themselves to different audiences simultaneously. Research suggests people are generally successful in this "multiple audience problem." Adding to previous research, the current research sought to examine factors that may limit this success by measuring social anxiety and placing participants into situations requiring them to either establish or preserve multiple impressions simultaneously. In general, participants were more successful when preserving previously conveyed impressions than when establishing impressions for the first time. In contrast, social anxiety did not affect multiple audience success. In all, this research offers valuable insight into potential challenges that people face in many social situations. © 2015 International Union of Psychological Science.

Facial First Impressions Across Culture: Data-Driven Modeling of Chinese and British Perceivers' Unconstrained Facial Impressions.

PubMed

Sutherland, Clare A M; Liu, Xizi; Zhang, Lingshan; Chu, Yingtung; Oldmeadow, Julian A; Young, Andrew W

2018-04-01

People form first impressions from facial appearance rapidly, and these impressions can have considerable social and economic consequences. Three dimensions can explain Western perceivers' impressions of Caucasian faces: approachability, youthful-attractiveness, and dominance. Impressions along these dimensions are theorized to be based on adaptive cues to threat detection or sexual selection, making it likely that they are universal. We tested whether the same dimensions of facial impressions emerge across culture by building data-driven models of first impressions of Asian and Caucasian faces derived from Chinese and British perceivers' unconstrained judgments. We then cross-validated the dimensions with computer-generated average images. We found strong evidence for common approachability and youthful-attractiveness dimensions across perceiver and face race, with some evidence of a third dimension akin to capability. The models explained ~75% of the variance in facial impressions. In general, the findings demonstrate substantial cross-cultural agreement in facial impressions, especially on the most salient dimensions.

EFFECT OF CONVENTIONAL AND EXPERIMENTAL GINGIVAL RETRACTION SOLUTIONS ON THE TENSILE STRENGTH AND INHIBITION OF POLYMERIZATION OF FOUR TYPES OF IMPRESSION MATERIALS

PubMed Central

Sábio, Sérgio; Franciscone, Paulo Afonso; Mondelli, José

2008-01-01

In the present study, two types of tests (tensile strength test and polymerization inhibition test) were performed to evaluate the physical and chemical properties of four impression materials [a polysulfide (Permlastic), a polyether (Impregum), a condensation silicone (Xantopren) and a polyvinylsiloxane (Aquasil)] when polymerized in contact with of one conventional (Hemostop) and two experimental (Vislin and Afrin) gingival retraction solutions. For the tensile strength test, the impression materials were mixed and packed into a steel plate with perforations that had residues of the gingival retraction solutions. After polymerization, the specimens were tested in tensile strength in a universal testing machine. For the polymerization inhibition test, specimens were obtained after taking impressions from a matrix with perforations that contained 1 drop of the gingival retraction solutions. Two independent examiners decided on whether or not impression material remnants remained unpolymerized, indicating interference of the chemical solutions. Based on the analysis of the results of both tests, the following conclusions were reached: 1. The tensile strength of the polysulfide decreased after contact with Hemostop and Afrin. 2. None of the chemical solutions inhibited the polymerization of the polysulfide; 3. The polyether presented lower tensile strength after polymerization in contact with the three gingival retraction agents; 4. The polyether had its polymerization inhibited only by Hemostop; 5. None of the chemical solutions affected the tensile strength of the condensation silicone; 6. Only Hemostop inhibited the polymerization of the condensation silicone; 7. The polyvinylsiloxane specimens polymerized in contact with Hemostop had significantly lower tensile strength; 8. Neither of the chemical solutions (Afrin and Vislin) affected the tensile strength of the polyvinylsiloxane and the condensation silicone; 9. Results of the tensile strength and polymerization inhibition tests suggest that Vislin can be used as substance of gingival retraction without affecting the tested properties of four impression materials. PMID:19089261

Effect of conventional and experimental gingival retraction solutions on the tensile strength and inhibition of polymerization of four types of impression materials.

PubMed

Sábio, Sérgio; Franciscone, Paulo Afonso; Mondelli, José

2008-01-01

In the present study, two types of tests (tensile strength test and polymerization inhibition test) were performed to evaluate the physical and chemical properties of four impression materials [a polysulfide (Permlastic), a polyether (Impregum), a condensation silicone (Xantopren) and a polyvinylsiloxane (Aquasil)] when polymerized in contact with of one conventional (Hemostop) and two experimental (Vislin and Afrin) gingival retraction solutions. For the tensile strength test, the impression materials were mixed and packed into a steel plate with perforations that had residues of the gingival retraction solutions. After polymerization, the specimens were tested in tensile strength in a universal testing machine. For the polymerization inhibition test, specimens were obtained after taking impressions from a matrix with perforations that contained 1 drop of the gingival retraction solutions. Two independent examiners decided on whether or not impression material remnants remained unpolymerized, indicating interference of the chemical solutions. Based on the analysis of the results of both tests, the following conclusions were reached: 1. The tensile strength of the polysulfide decreased after contact with Hemostop and Afrin. 2. None of the chemical solutions inhibited the polymerization of the polysulfide; 3. The polyether presented lower tensile strength after polymerization in contact with the three gingival retraction agents; 4. The polyether had its polymerization inhibited only by Hemostop; 5. None of the chemical solutions affected the tensile strength of the condensation silicone; 6. Only Hemostop inhibited the polymerization of the condensation silicone; 7. The polyvinylsiloxane specimens polymerized in contact with Hemostop had significantly lower tensile strength; 8. Neither of the chemical solutions (Afrin and Vislin) affected the tensile strength of the polyvinylsiloxane and the condensation silicone; 9. Results of the tensile strength and polymerization inhibition tests suggest that Vislin can be used as substance of gingival retraction without affecting the tested properties of four impression materials.

Evaluation of setting time and flow properties of self-synthesize alginate impressions

NASA Astrophysics Data System (ADS)

Halim, Calista; Cahyanto, Arief; Sriwidodo, Harsatiningsih, Zulia

2018-02-01

Alginate is an elastic hydrocolloid dental impression materials to obtain negative reproduction of oral mucosa such as to record soft-tissue and occlusal relationships. The aim of the present study was to synthesize alginate and to determine the setting time and flow properties. There were five groups of alginate consisted of fifty samples self-synthesize alginate and commercial alginate impression product. Fifty samples were divided according to two tests, each twenty-five samples for setting time and flow test. Setting time test was recorded in the s unit, meanwhile, flow test was recorded in the mm2 unit. The fastest setting time result was in the group three (148.8 s) and the latest was group fours). The highest flow test result was in the group three (69.70 mm2) and the lowest was group one (58.34 mm2). Results were analyzed statistically by one way ANOVA (α= 0.05), showed that there was a statistical significance of setting time while no statistical significance of flow properties between self-synthesize alginate and alginate impression product. In conclusion, the alginate impression was successfully self-synthesized and variation composition gives influence toward setting time and flow properties. The most resemble setting time of control group is group three. The most resemble flow of control group is group four.

Empirical study of alginate impression materials by customized proportioning system

PubMed Central

2016-01-01

PURPOSE Alginate mixers available in the market do not have the automatic proportioning unit. In this study, an automatic proportioning unit for the alginate mixer and controller software were designed and produced for a new automatic proportioning unit. With this device, it was ensured that proportioning operation could arrange weight-based alginate impression materials. MATERIALS AND METHODS The variation of coefficient in the tested groups was compared with the manual proportioning. Compression tension and tear tests were conducted to determine the mechanical properties of alginate impression materials. The experimental data were statistically analyzed using one way ANOVA and Tukey test at the 0.05 level of significance. RESULTS No statistically significant differences in modulus of elastisity (P>0.3), tensional/compresional strength (P>0.3), resilience (P>0.2), strain in failure (P>0.4), and tear energy (P>0.7) of alginate impression materials were seen. However, a decrease in the standard deviation of tested groups was observed when the customized machine was used. To verify the efficiency of the system, powder and powder/water mixing were weighed and significant decrease was observed. CONCLUSION It was possible to obtain more mechanically stable alginate impression materials by using the custom-made proportioning unit. PMID:27826387

The Historical Evolution of Dental Impression Materials.

PubMed

Papadiochos, Ioannis; Papadiochou, Sofia; Emmanouil, Ioannis

The concept of impression making process in dentistry began in the mid 1800s. Dentists realized that the construction of a prosthetic restoration required both a detailed capture of the oral tissues along with stone cast fabrications. To accomplish these goals, impression materials were essential. Beeswax represents the first impression material, while important bechmarks during the historical evolution of dental impression materials are considered to be the introduction of dental trays in the early 1800s and the invention of the gutta-percha, thermoplastic resins and plaster of Paris. The double (corrective) impression technique, along with the functional impression concept that was established after mid 1800s, are also identified as pivotal innovations. During the 20th century, the advances in material development slowed significantly since the majority of the current impression materials had already been invented. However, the introduction of elastomeric impression materials in the field of prosthodontics that offered the advantages of accuracy and dimensional stability substantially upgraded both the impression accuracy and the quality of the final restoration. Presently, the dental practitioner has access to a variety of impression materials and should be aware of their properties, indications and limitations as well. Futhermore, while continuous attempts are being made to enhance these materials, the ideal impression material has yet to be developed. The purpose of this article was to provide a comprehensive review about the historical development of impression dental materials. Copyright American Academy of the History of Dentistry.

Extrusion-mixing compared with hand-mixing of polyether impression materials?

PubMed

McMahon, Caroline; Kinsella, Daniel; Fleming, Garry J P

2010-12-01

The hypotheses tested were two-fold (a) whether altering the base:catalyst ratio influences working time, elastic recovery and strain in compression properties of a hand-mixed polyether impression material and (b) whether an extrusion-mixed polyether impression material would have a significant advantage over a hand-mixed polyether impression material mixed to the optimum base:catalyst ratio. The polyether was hand-mixed at the optimum (manufacturers recommended) base:catalyst ratios (7:1) and further groups were made by increasing or decreasing the catalyst length by 25%. Additionally specimens were also made from an extrusion-mixed polyether impression material and compared with the optimum hand-mixed base:catalyst ratio. A penetrometer assembly was used to measure the working time (n=5). Five cylindrical specimens for each hand-mixed and extrusion mixed group investigated were employed for elastic recovery and strain in compression testing. Hand-mixing polyether impression materials with 25% more catalyst than that recommended significantly decreased the working time while hand-mixing with 25% less catalyst than that recommended significantly increased the strain in compression. The extrusion-mixed polyether impression material provided similar working time, elastic recovery and strain in compression to the hand-mixed polyether mixed at the optimum base:catalyst ratio.

Precision of guided scanning procedures for full-arch digital impressions in vivo.

PubMed

Zimmermann, Moritz; Koller, Christina; Rumetsch, Moritz; Ender, Andreas; Mehl, Albert

2017-11-01

System-specific scanning strategies have been shown to influence the accuracy of full-arch digital impressions. Special guided scanning procedures have been implemented for specific intraoral scanning systems with special regard to the digital orthodontic workflow. The aim of this study was to evaluate the precision of guided scanning procedures compared to conventional impression techniques in vivo. Two intraoral scanning systems with implemented full-arch guided scanning procedures (Cerec Omnicam Ortho; Ormco Lythos) were included along with one conventional impression technique with irreversible hydrocolloid material (alginate). Full-arch impressions were taken three times each from 5 participants (n = 15). Impressions were then compared within the test groups using a point-to-surface distance method after best-fit model matching (OraCheck). Precision was calculated using the (90-10%)/2 quantile and statistical analysis with one-way repeated measures ANOVA and post hoc Bonferroni test was performed. The conventional impression technique with alginate showed the lowest precision for full-arch impressions with 162.2 ± 71.3 µm. Both guided scanning procedures performed statistically significantly better than the conventional impression technique (p < 0.05). Mean values for group Cerec Omnicam Ortho were 74.5 ± 39.2 µm and for group Ormco Lythos 91.4 ± 48.8 µm. The in vivo precision of guided scanning procedures exceeds conventional impression techniques with the irreversible hydrocolloid material alginate. Guided scanning procedures may be highly promising for clinical applications, especially for digital orthodontic workflows.

Comparison of implant cast accuracy of multiple implant impression technique with different splinting materials: An in vitro study

PubMed Central

Selvaraj, Sunantha; Dorairaj, Jayachandran; Mohan, Jayashree; Simon, Paul

2016-01-01

Introduction: An accurate and passive fit of implant framework prosthesis, as well as the successful surgical operation is suggested as one of the critical requirements for long-term implant success. Objective: The purpose of this in vitro study was to evaluate the accuracy of the master cast using open tray impression technique with conventional and novel splinting materials. Methodology: A mandibular reference model with four ADIN implants was done. Ten custom trays were fabricated using the light curable resin sheets. Medium body polyether impression material was used. These trays were randomly divided between the two groups, with five trays in each group. Impression techniques were divided into two groups namely: Group A: Direct impression technique with open tray impression copings splinted with autopolymerizing acrylic resin (GC pattern resin). Group B: Direct impression technique with open tray impression copings splinted with Pro-temp TM 4 (bis-GMA) syringable temporization material. Thus, final impressions were made. Total of 10 master casts were fabricated. Evaluation of casts using Dynascope-Vision Engineering, TESA microhite two- dimension and coordinate measuring machine were used. Results: Statistical comparisons were made using ANOVA test and post-hoc test. Same amount of deviation values obtained with resin splinted and bis-GMA splinted impression copings. Conclusion: The master cast obtained by both the splinting material exhibits no difference from the reference model. So bis-GMA can be used, which is easy to handle, less time consuming, less technique sensitive, rigid, and readily available material in clinics. PMID:27141167

Remembering first impressions: effects of intentionality and diagnosticity on subsequent memory.

PubMed

Gilron, Roee; Gutchess, Angela H

2012-03-01

People rely on first impressions every day as an important tool to interpret social behavior. While research is beginning to reveal the neural underpinnings of first impressions, particularly through understanding the role of dorsal medial prefrontal cortex (dmPFC), little is known about the way in which first impressions are encoded into memory. This is surprising because first impressions are relevant from a social perspective for future interactions, requiring that they be transferred to memory. The present study used a subsequent-memory paradigm to test the conditions under which the dmPFC is implicated in the encoding of first impressions. We found that intentionally forming impressions engages the dmPFC more than does incidentally forming impressions, and that this engagement supports the encoding of remembered impressions. In addition, we found that diagnostic information, which more readily lends itself to forming trait impressions, engages the dmPFC more than does neutral information. These results indicate that the neural system subserving memory for impressions is sensitive to consciously formed impressions. The results also suggest a distinction between a social memory system and other explicit memory systems governed by the medial temporal lobes.

Remembering first impressions: Effects of intentionality and diagnosticity on subsequent memory

PubMed Central

Gilron, Roee; Gutchess, Angela H.

2012-01-01

People rely on first impressions every day as an important tool to interpret social behavior. While research is beginning to reveal the neural underpinnings of first impressions, particularly through understanding the role of dorsal medial prefrontal cortex (dmPFC), little is known about the way in which first impressions are encoded into memory. This is surprising because first impressions are relevant from a social perspective for future interactions, requiring that they be transferred to memory. The present study used a subsequent memory paradigm to test the conditions under which the dmPFC is implicated in the encoding of first impressions. We found that intentionally forming impressions engages the dmPFC more than incidentally forming impressions and that this engagement supports the encoding of remembered impressions. In addition, we found that diagnostic information, which more readily lends itself to forming trait impressions, engages the dmPFC more than neutral information. These results indicate that the neural system subserving memory for impressions is sensitive to consciously formed impressions. The results also suggest a distinction between a social memory system and other explicit memory systems governed by the medial temporal lobes. PMID:22139633

Accuracy of six elastic impression materials used for complete-arch fixed partial dentures.

PubMed

Stauffer, J P; Meyer, J M; Nally, J N

1976-04-01

1. The accuracy of four types of impression materials used to make a complete-arch fixed partial denture was evaluated by visual comparison and indirect measurement methods. 2. None of the tested materials allows safe finishing of a complete-arch fixed partial denture on a cast poured from one single master impression. 3. All of the tested materials can be used for impressions for a complete-arch fixed partial denture provided it is not finished on one single cast. Errors can be avoided by making a new impression with the fitted castings in place. Assembly and soldering should be done on the second cast. 4. In making the master fixed partial denture for this study, inaccurate soldering was a problem that was overcome with the use of epoxy glue. Hence, soldering seems to be a major source of inaccuracy for every fixed partial denture.

Accuracy of a new elastomeric impression material for complete-arch dental implant impressions.

PubMed

Baig, Mirza R; Buzayan, Muaiyed M; Yunus, Norsiah

2018-05-01

The aim of the present study was to assess the accuracy of multi-unit dental implant casts obtained from two elastomeric impression materials, vinyl polyether silicone (VPES) and polyether (PE), and to test the effect of splinting of impression copings on the accuracy of implant casts. Forty direct impressions of a mandibular reference model fitted with six dental implants and multibase abutments were made using VPES and PE, and implant casts were poured (N = 20). The VPES and PE groups were split into four subgroups of five each, based on splinting type: (a) no splinting; (b) bite registration polyether; (c) bite registration addition silicone; and (d) autopolymerizing acrylic resin. The accuracy of implant-abutment replica positions was calculated on the experimental casts, in terms of interimplant distances in the x, y, and z-axes, using a coordinate measuring machine; values were compared with those measured on the reference model. Data were analyzed using non-parametrical Kruskal-Wallis and Mann-Whitney tests at α = .05. The differences between the two impression materials, VPES and PE, regardless of splinting type, were not statistically significant (P>.05). Non-splinting and splinting groups were also not significantly different for both PE and VPES (P>.05). The accuracy of VPES impression material seemed comparable with PE for multi-implant abutment-level impressions. Splinting had no effect on the accuracy of implant impressions. © 2018 John Wiley & Sons Australia, Ltd.

Retention strength of impression materials to a tray material using different adhesive methods: an in vitro study.

PubMed

Marafie, Yousef; Looney, Stephen; Nelson, Steven; Chan, Daniel; Browning, William; Rueggeberg, Frederick

2008-12-01

A new self-stick adhesive system has been purported to eliminate the need to use chemical adhesives with plastic impression trays; however, no testing has confirmed the claim. The purpose of this study was to compare the in vitro retentive strength of impression materials to plastic substrates having conventional adhesive (CA) or the self-stick adhesive system, with and without mechanical retention. Three types of impression materials (irreversible hydrocolloid (IH), vinyl polysiloxane (VPS), and polyether (PE)) were applied to polystyrene disc-shaped surfaces (33.68 cm(2)) that were held on the arms of a universal testing machine. The appropriate CA or the self-stick adhesive system (Self-Stick Dots) (SSD) was applied to the plates, which had either no mechanical retention, or equally spaced mechanical perforations (n=4). An in vivo pilot test determined the appropriate rate of plate separation. Plates with impression material were lowered to provide 4 mm of space, the material set, and plates were separated using the appropriate speed. Force at first separation was divided by plate area (peak stress). Five replications per test condition were made, and results were analyzed using ANOVA and Bonferroni-adjusted t tests (alpha=.05). Within each impression material/test combination, stress using SSD was significantly lower than CA (P<.05). Mechanical retention did not always provide significantly greater strength. The combination of mechanical retention and CA yielded the highest strength within each material type, except for PE, for which nonmechanical and CA strength did not differ from that of mechanical and CA. Use of the self-stick adhesive system provided significantly lower retentive strength to plastic tray material than chemical adhesives for irreversible hydrocolloid, vinyl polysiloxane, and polyether.

Comparison of digital and conventional impression techniques: evaluation of patients' perception, treatment comfort, effectiveness and clinical outcomes.

PubMed

Yuzbasioglu, Emir; Kurt, Hanefi; Turunc, Rana; Bilir, Halenur

2014-01-30

The purpose of this study was to compare two impression techniques from the perspective of patient preferences and treatment comfort. Twenty-four (12 male, 12 female) subjects who had no previous experience with either conventional or digital impression participated in this study. Conventional impressions of maxillary and mandibular dental arches were taken with a polyether impression material (Impregum, 3 M ESPE), and bite registrations were made with polysiloxane bite registration material (Futar D, Kettenbach). Two weeks later, digital impressions and bite scans were performed using an intra-oral scanner (CEREC Omnicam, Sirona). Immediately after the impressions were made, the subjects' attitudes, preferences and perceptions towards impression techniques were evaluated using a standardized questionnaire. The perceived source of stress was evaluated using the State-Trait Anxiety Scale. Processing steps of the impression techniques (tray selection, working time etc.) were recorded in seconds. Statistical analyses were performed with the Wilcoxon Rank test, and p < 0.05 was considered significant. There were significant differences among the groups (p < 0.05) in terms of total working time and processing steps. Patients stated that digital impressions were more comfortable than conventional techniques. Digital impressions resulted in a more time-efficient technique than conventional impressions. Patients preferred the digital impression technique rather than conventional techniques.

Reversing Implicit First Impressions through Reinterpretation after a Two-Day Delay

PubMed Central

Mann, Thomas C.; Ferguson, Melissa J.

2016-01-01

People are adept at forming impressions of others, but how easily can impressions be updated? Although implicit first impressions have been characterized as difficult to overturn, recent work shows that they can be reversed through reinterpretation of earlier learning. However, such reversal has been demonstrated only in the same experimental session in which the impression formed, suggesting that implicit updating might be possible only within a brief temporal window, before impressions are consolidated and when memory about the initial information is strongest. Implicit impressions may be unable to be revised when reinterpreting details are learned later, due to memory consolidation or forgetting of the details to be reinterpreted. This study tested whether implicit first impressions can be reversed through reinterpretation after a two-day delay following the initial formation. Results showed that implicit revision emerged after the delay, even among those with poor explicit recall or who were not cued to recall. We discuss implications for theory on impression formation and updating. PMID:28017977

Reversing Implicit First Impressions through Reinterpretation after a Two-Day Delay.

PubMed

Mann, Thomas C; Ferguson, Melissa J

2017-01-01

People are adept at forming impressions of others, but how easily can impressions be updated? Although implicit first impressions have been characterized as difficult to overturn, recent work shows that they can be reversed through reinterpretation of earlier learning. However, such reversal has been demonstrated only in the same experimental session in which the impression formed, suggesting that implicit updating might be possible only within a brief temporal window, before impressions are consolidated and when memory about the initial information is strongest. Implicit impressions may be unable to be revised when reinterpreting details are learned later, due to memory consolidation or forgetting of the details to be reinterpreted. This study tested whether implicit first impressions can be reversed through reinterpretation after a two-day delay following the initial formation. Results showed that implicit revision emerged after the delay, even among those with poor explicit recall or who were not cued to recall. We discuss implications for theory on impression formation and updating.

A Comparison of implant impression precision: Different materials and techniques

PubMed Central

Tabesh, Mahtab; Alikhasi, Marzieh

2018-01-01

Background Precision of implant impressions is a prerequisite for long-term success of implant supported prostheses. Impression materials and impression techniques are two important factors that impression precision relies on. Material and Methods A model of edentulous maxilla containing four implants inserted by All-on-4 guide was constructed. Seventy two impressions using polyether (PE), polyvinyl siloxane (PVS), and vinyl siloxanether (VSE) materials with direct and indirect techniques were made (n=12). Coordinates of implants in casts were measured using coordinate measuring machine (CMM). Data were analyzed with ANOVA; t-test and Tukey test were used for post hoc. Results With two-way ANOVA, mean values of linear displacements of implants were significantly different among materials and techniques. One-way ANOVA and Tukey showed significant difference between PE and VSE (P=0.019), PE and PVS (P=0.002) in direct technique, and between PVS and PE (P<0.001), PVS and VSE (P<0.001) in indirect technique. One-way ANOVA and t-test showed significant difference between the two techniques in PVS groups (P<0.001) and in PE groups (P=0.02). Two-way ANOVA showed mean values of rotational displacement of implants were significantly different among materials. One-way ANOVA and Tukey test showed significant difference between PVS and PE (P=0.001) and between PVS and VSE (P=0.012) in indirect groups. Conclusions On the basis of the results, when deciding on the material to make an impression of implants, PE is recommended for direct technique while PE and VSE are recommended for indirect technique. Recommended technique for VSE is either direct or indirect; and for PE and PVS is direct. Key words:Polyvinyl siloxane, polyether, vinyl siloxanether, direct technique, indirect technique, All-on-4, coordinate measuring machine. PMID:29670733

Effect of Time on Gypsum-Impression Material Compatibility

NASA Astrophysics Data System (ADS)

Won, John Boram

The purpose of this study was to evaluate the compatibility of dental gypsum with three recently introduced irreversible hydrocolloid (alginate) alternatives. The test materials were Alginot® (Kerr™), Position Penta Quick® (3M ESPE™) and Silgimix ® (Sultan Dental™). The irreversible hydrocolloid impression material, Jeltrate Plus antimicrobial® (Dentsply Caulk™) served as the control. Materials and Methods: Testing of materials was conducted in accordance with ANSI/ADA Specification No. 18 for Alginate Impression Materials. Statistical Analysis: The 3-Way ANOVA test was used to analyze measurements between different time points at a significance level of (p < 0.05). Outcome: It was found that there was greater compatibility between gypsum and the alternative materials over time than the traditional irreversible hydrocolloid material that was tested. A statistically significant amount of surface change/incompatibility was found over time with the combination of the dental gypsum products and the control impression material (Jeltrate Plus antimicrobial®).

Effect of storage time on the viscoelastic properties of elastomeric impression materials.

PubMed

Papadogiannis, Dimitris; Lakes, Roderic; Palaghias, George; Papadogiannis, Yiannis

2012-01-01

The aim of this study was to evaluate creep and viscoelastic properties of dental impression materials after different storage times. Six commercially available impression materials (one polyether and five silicones) were tested after being stored for 30 min to 2 weeks under both static and dynamic testing. Shear and Young's moduli, dynamic viscosity, loss tangent and other viscoelastic parameters were calculated. Four of the materials were tested 1 h after setting under creep for three hours and recovery was recorder for 50 h. The tested materials showed differences among them, while storage time had significant influence on their properties. Young's modulus E ranged from 1.81 to 12.99 MPa with the polyether material being the stiffest. All of the materials showed linear viscoelastic behavior exhibiting permanent deformation after 50h of creep recovery. As storage time affects the materials' properties, pouring time should be limited in the first 48 h after impression. Copyright © 2011 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Comparative Evaluation of Dimensional Accuracy of Elastomeric Impression Materials when Treated with Autoclave, Microwave, and Chemical Disinfection.

PubMed

Kamble, Suresh S; Khandeparker, Rakshit Vijay; Somasundaram, P; Raghav, Shweta; Babaji, Rashmi P; Varghese, T Joju

2015-09-01

Impression materials during impression procedure often get infected with various infectious diseases. Hence, disinfection of impression materials with various disinfectants is advised to protect the dental team. Disinfection can alter the dimensional accuracy of impression materials. The present study was aimed to evaluate the dimensional accuracy of elastomeric impression materials when treated with different disinfectants; autoclave, chemical, and microwave method. The impression materials used for the study were, dentsply aquasil (addition silicone polyvinylsiloxane syringe and putty), zetaplus (condensation silicone putty and light body), and impregum penta soft (polyether). All impressions were made according to manufacturer's instructions. Dimensional changes were measured before and after different disinfection procedures. Dentsply aquasil showed smallest dimensional change (-0.0046%) and impregum penta soft highest linear dimensional changes (-0.026%). All the tested elastomeric impression materials showed some degree of dimensional changes. The present study showed that all the disinfection procedures produce minor dimensional changes of impression material. However, it was within American Dental Association specification. Hence, steam autoclaving and microwave method can be used as an alternative method to chemical sterilization as an effective method.

Modeling of Impression Testing to Obtain Mechanical Properties of Lead-Free Solders Microelectronic Interconnects

DTIC Science & Technology

2005-12-01

hardening exponent and Cimp is the impression strain-rate hardening coefficient. The strain-rate hardening exponent m is a parameter that is...exponent and Cimp is the impression strain-rate hardening coefficient. The strain-rate hardening exponent m is a parameter that is related to the creep

Coping with stereotype threat: denial as an impression management strategy.

PubMed

von Hippel, William; von Hippel, Courtney; Conway, Leanne; Preacher, Kristopher J; Schooler, Jonathan W; Radvansky, Gabriel A

2005-07-01

Four experiments tested the hypothesis that people who are concerned with impression management cope with stereotype threat through denial. Consistent with this hypothesis, temporary employees threatened by a stereotype of incompetence (Study 1) and hostel-dwelling older adults (Study 2) were more likely to deny incompetence if they were high in impression management. African Americans (Study 3) showed a similar pattern of denying cognitive incompetence, which emerged primarily when they were interviewed by a White experimenter and had attended a predominantly Black high school. In Study 4, White students who expected to take an IQ test and were threatened by a stereotype of being less intelligent than Asians were more likely to deny that intelligence is important if they were high in impression management.

Accuracy of impression scanning compared with stone casts of implant impressions.

PubMed

Matta, Ragai Edward; Adler, Werner; Wichmann, Manfred; Heckmann, Siegfried Martin

2017-04-01

Accurate virtual implant models are a necessity for the fabrication of precisely fitting superstructures. The purpose of this in vitro study was to evaluate different methods with which to build an accurate virtual model of a 3-dimensional implant in the oral cavity; this model would then be used for iterative computer-aided design and computer-aided manufacturing (CAD-CAM) procedures. A titanium master model with 3 rigidly connected implants was manufactured and digitized with a noncontact industrial scanner to obtain a virtual master model. Impressions of the master model with the implant position locators (IPL) were made using vinyl siloxanether material. The impressions were scanned (Impression scanning technique group). For the transfer technique and pick-up technique groups (each group n=20), implant analogs were inserted into the impression copings, impressions were made using polyether, and casts were poured in Type 4 gypsum. The IPLs were screwed into the analogs and scanned. To compare the virtual master model with each virtual test model, a CAD interactive software, ATOS professional, was applied. The Kruskal-Wallis test was subsequently used to determine the overall difference between groups, with the Mann-Whitney U test used for pairwise comparisons. Through Bonferroni correction, the α-level was set to .017. The outcome revealed a significant difference among the 3 groups (P<.01) in terms of accuracy. With regard to total deviation, for all axes, the transfer technique generated the greatest divergence, 0.078 mm (±0.022), compared with the master model. Deviation with the pick-up technique was 0.041 mm (±0.009), with impression scanning generating the most accurate models with a deviation of 0.022 mm (±0.007). The impression scanning method improved the precision of CAD-CAM-fabricated superstructures. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

A complete denture impression technique survey of postdoctoral prosthodontic programs in the United States.

PubMed

Mehra, Mamta; Vahidi, Farhad; Berg, Robert W

2014-06-01

The purpose of the study was to survey program directors of postdoctoral prosthodontic programs in the United States regarding their programs' complete denture impression techniques. The key objectives of the survey were to identify the current trends in complete denture impression making and to determine which techniques and materials are taught in US postdoctoral prosthodontic programs. An online survey was sent to all program directors of US postdoctoral prosthodontic programs. The survey comprised two sections: preliminary impressions and final impressions. The survey contained 22 questions that would take approximately 5 minutes to complete. All responses remained anonymous throughout the survey. The response rate for the survey was 87%. A majority of the programs did not separately border mold the tray prior to making the preliminary impressions (82%). The impression material of choice for the preliminary impression was irreversible hydrocolloid (88%). Selective pressure was the predominantly used impression philosophy (80%). All programs border molded the custom tray, and 95% recorded the borders in sections. The material of choice for border molding the custom tray was modeling plastic impression compound (71%). The most commonly used impression material for the final impressions was polyvinylsiloxane (PVS) (42%), and the second most commonly used impression material was polysulphide (32%). The most common technique for locating the posterior palatal seal was marking intraorally and transferring onto the final impression (65%). Most programs routinely advised their patients not to wear their existing dentures for at least 24 hours before the final impressions were made (83%). Based on the results of this study, the following conclusions can be drawn: (1) The most commonly used material for the preliminary impression was irreversible hydrocolloid and for the final impression was PVS. (2) Modeling plastic impression compound was used by most programs to border mold the custom trays. (3) Selective pressure was the predominantly used impression philosophy. (4) A majority of the programs made a special consideration for excessive movable (flabby) tissue. (5) Most programs routinely advised their patients to not wear their existing dentures for at least 24 hours before the final impressions were made. © 2013 by the American College of Prosthodontists.

Full-arch implant fixed prostheses: a comparative study on the effect of connection type and impression technique on accuracy of fit.

PubMed

Papaspyridakos, Panos; Hirayama, Hiroshi; Chen, Chun-Jung; Ho, Chung-Han; Chronopoulos, Vasilios; Weber, Hans-Peter

2016-09-01

The aim of this study was to assess the effect of connection type and impression technique on the accuracy of fit of implant-supported fixed complete-arch dental prostheses (IFCDPs). An edentulous mandibular cast with five implants was fabricated to serve as master cast (control) for both implant- and abutment-level baselines. A titanium one-piece framework for an IFCDP was milled at abutment level and used for accuracy of fit measurements. Polyether impressions were made using a splinted and non-splinted technique at the implant and abutment level leading to four test groups, n = 10 each. Hence, four groups of test casts were generated. The impression accuracy was evaluated indirectly by assessing the fit of the IFCDP framework on the generated casts of the test groups, clinically and radiographically. Additionally, the control and all test casts were digitized with a high-resolution reference scanner (IScan D103i, Imetric, Courgenay, Switzerland) and standard tessellation language datasets were generated and superimposed. Potential correlations between the clinical accuracy of fit data and the data from the digital scanning were investigated. To compare the accuracy of casts of the test groups versus the control at the implant and abutment level, Fisher's exact test was used. Of the 10 casts of test group I (implant-level splint), all 10 presented with accurate clinical fit when the framework was seated on its respective cast, while only five of 10 casts of test group II (implant-level non-splint) showed adequate fit. All casts of group III (abutment-level splint) presented with accurate fit, whereas nine of 10 of the casts of test group IV (abutment-level non-splint) were accurate. Significant 3D deviations (P < 0.05) were found between group II and the control. No statistically significant differences were found between groups I, III, and IV compared with the control. Implant connection type (implant level vs. abutment level) and impression technique did affect the 3D accuracy of implant impressions only with the non-splint technique (P < 0.05). For one-piece IFCDPs, the implant-level splinted impression technique showed to be more accurate than the non-splinted approach, whereas at the abutment-level, no difference in the accuracy was found. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Impression Testing of Self-Healing Polymers

NASA Technical Reports Server (NTRS)

Hinkley, Jeffrey A.; Huber, Amy

2005-01-01

As part of the BIOSANT program (biologically-inspired smart nanotechnology), scientists at NASA-Langley have identified a "self-healing" plastic that spontaneously closes the hole left by the passage of a bullet. To understand and generalize the phenomenon in question, the mechanical properties responsible for this ability are being explored. Low-rate impression testing was chosen to characterize post-yield material properties, and it turned out that materials that heal following ballistic puncture also show up to 80% healing of the low-rate impression. Preliminary results on the effects of temperature and rate of puncture are presented.

Impressed sources and fields in the volume-integral-equation formulation of electromagnetic scattering by a finite object: A tutorial

NASA Astrophysics Data System (ADS)

Mishchenko, Michael I.; Yurkin, Maxim A.

2018-07-01

Although free space cannot generate electromagnetic waves, the majority of existing accounts of frequency-domain electromagnetic scattering by particles and particle groups are based on the postulate of existence of an impressed incident field, usually in the form of a plane wave. In this tutorial we discuss how to account for the actual existence of impressed source currents rather than impressed incident fields. Specifically, we outline a self-consistent theoretical formalism describing electromagnetic scattering by an arbitrary finite object in the presence of arbitrarily distributed impressed currents, some of which can be far removed from the object and some can reside in its vicinity, including inside the object. To make the resulting formalism applicable to a wide range of scattering-object morphologies, we use the framework of the volume integral equation formulation of electromagnetic scattering, couple it with the notion of the transition operator, and exploit the fundamental symmetry property of this operator. Among novel results, this tutorial includes a streamlined proof of fundamental symmetry (reciprocity) relations, a simplified derivation of the Foldy equations, and an explicit analytical expression for the transition operator of a multi-component scattering object.

Impression Management in the Job Interview: An Effective Way of Mitigating Discrimination against Older Applicants?

PubMed

Gioaba, Irina; Krings, Franciska

2017-01-01

The increasingly aging population in most industrialized societies, coupled with the rather age-diverse current workforce makes discrimination against older employees a prevalent issue, especially in employment contexts. This renders research on ways for reducing this type of discrimination a particularly pressing concern. Drawing on theories of social identity and impression management, our research examines the role of impression management, aimed at refuting common older worker stereotypes, in diminishing bias against older job applicants during the job interview. The study consisted in an experimental hiring simulation conducted on a sample of 515 undergraduate students. Results show that older applicants who used impression management to contradict common older worker stereotypes were perceived as more hirable than those who did not. However, despite this positive effect, discrimination persisted: older applicants were consistently rated as less hirable than their younger counterparts when displaying the same IM behavior. Taken together, this research demonstrates that older job seekers can indeed ameliorate biased interview outcomes by engaging in impression management targeting common age stereotypes; however, it also shows that this strategy is insufficient for overcoming age discrimination entirely. The current study has important implications for theory, by expanding research on the use of impression management in mitigating age discrimination, as well as for practice, by offering older employees a hands-on strategy to reduce bias and stereotyping against them.

Impression Management in the Job Interview: An Effective Way of Mitigating Discrimination against Older Applicants?

PubMed Central

Gioaba, Irina; Krings, Franciska

2017-01-01

The increasingly aging population in most industrialized societies, coupled with the rather age-diverse current workforce makes discrimination against older employees a prevalent issue, especially in employment contexts. This renders research on ways for reducing this type of discrimination a particularly pressing concern. Drawing on theories of social identity and impression management, our research examines the role of impression management, aimed at refuting common older worker stereotypes, in diminishing bias against older job applicants during the job interview. The study consisted in an experimental hiring simulation conducted on a sample of 515 undergraduate students. Results show that older applicants who used impression management to contradict common older worker stereotypes were perceived as more hirable than those who did not. However, despite this positive effect, discrimination persisted: older applicants were consistently rated as less hirable than their younger counterparts when displaying the same IM behavior. Taken together, this research demonstrates that older job seekers can indeed ameliorate biased interview outcomes by engaging in impression management targeting common age stereotypes; however, it also shows that this strategy is insufficient for overcoming age discrimination entirely. The current study has important implications for theory, by expanding research on the use of impression management in mitigating age discrimination, as well as for practice, by offering older employees a hands-on strategy to reduce bias and stereotyping against them. PMID:28559869

Comparison of digital and conventional impression techniques: evaluation of patients’ perception, treatment comfort, effectiveness and clinical outcomes

PubMed Central

2014-01-01

Background The purpose of this study was to compare two impression techniques from the perspective of patient preferences and treatment comfort. Methods Twenty-four (12 male, 12 female) subjects who had no previous experience with either conventional or digital impression participated in this study. Conventional impressions of maxillary and mandibular dental arches were taken with a polyether impression material (Impregum, 3 M ESPE), and bite registrations were made with polysiloxane bite registration material (Futar D, Kettenbach). Two weeks later, digital impressions and bite scans were performed using an intra-oral scanner (CEREC Omnicam, Sirona). Immediately after the impressions were made, the subjects’ attitudes, preferences and perceptions towards impression techniques were evaluated using a standardized questionnaire. The perceived source of stress was evaluated using the State-Trait Anxiety Scale. Processing steps of the impression techniques (tray selection, working time etc.) were recorded in seconds. Statistical analyses were performed with the Wilcoxon Rank test, and p < 0.05 was considered significant. Results There were significant differences among the groups (p < 0.05) in terms of total working time and processing steps. Patients stated that digital impressions were more comfortable than conventional techniques. Conclusions Digital impressions resulted in a more time-efficient technique than conventional impressions. Patients preferred the digital impression technique rather than conventional techniques. PMID:24479892

In Vitro Comparative Evaluation of Different Types of Impression Trays and Impression Materials on the Accuracy of Open Tray Implant Impressions: A Pilot Study

PubMed Central

Gupta, Sonam; Balakrishnan, Dhanasekar

2017-01-01

Purpose. For a precise fit of multiple implant framework, having an accurate definitive cast is imperative. The present study evaluated dimensional accuracy of master casts obtained using different impression trays and materials with open tray impression technique. Materials and Methods. A machined aluminum reference model with four parallel implant analogues was fabricated. Forty implant level impressions were made. Eight groups (n = 5) were tested using impression materials (polyether and vinylsiloxanether) and four types of impression trays, two being custom (self-cure acrylic and light cure acrylic) and two being stock (plastic and metal). The interimplant distances were measured on master casts using a coordinate measuring machine. The collected data was compared with a standard reference model and was statistically analyzed using two-way ANOVA. Results. Statistically significant difference (p < 0.05) was found between the two impression materials. However, the difference seen was small (36 μm) irrespective of the tray type used. No significant difference (p > 0.05) was observed between varied stock and custom trays. Conclusions. The polyether impression material proved to be more accurate than vinylsiloxanether impression material. The rigid nonperforated stock trays, both plastic and metal, could be an alternative for custom trays for multi-implant impressions when used with medium viscosity impression materials. PMID:28348595

Patient-centered outcomes comparing digital and conventional implant impression procedures: a randomized crossover trial.

PubMed

Joda, Tim; Brägger, Urs

2016-12-01

The aim of this randomized controlled trial was to compare patient-centered outcomes during digital and conventional implant impressions. In a crossover study design, intraoral scanning (IOS) [test] as well as classical polyether impressions [control] were both performed on 20 patients for single-tooth replacement with implant-supported crowns. The sequential distribution of either starting with the test or the control procedure was randomly selected. Patients' perception and satisfaction on the level of convenience-related factors were assessed with visual analogue scale (VAS) questionnaires. In addition, clinical work time was separately recorded for test and control procedures. Statistical analyses were performed with Wilcoxon signed-rank tests and corrected for multiple testing by the method of Holm. On VAS ranging from 0 to 100, patients scored a mean convenience level of 78.6 (SD ± 14.0) in favor of IOS compared to conventional impressions with 53.6 (SD ± 15.4) [P = 0.0001]. All included patients would prefer the digital workflow if in the future they could choose between the two techniques. Secondary, IOS was significantly faster with 14.8 min (SD ± 2.2) compared to the conventional approach with 17.9 min (SD ± 1.1) [P = 0.0001]. Based on the findings of this investigation, both impression protocols worked successfully for all study participants capturing the 3D implant positions. However, the digital technique emerges as the most preferred one according to patient-centered outcomes and was more time-effective compared to conventional impressions. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A new method for assessing the accuracy of full arch impressions in patients.

PubMed

Kuhr, F; Schmidt, A; Rehmann, P; Wöstmann, B

2016-12-01

To evaluate a new method of measuring the real deviation (trueness) of full arch impressions intraorally and to investigate the trueness of digital full arch impressions in comparison to a conventional impression procedure in clinical use. Four metal spheres were fixed with composite using a metal application aid to the lower teeth of 50 test subjects as reference structures. One conventional impression (Impregum Penta Soft) with subsequent type-IV gypsum model casting (CI) and three different digital impressions were performed in the lower jaw of each test person with the following intraoral scanners: Sirona CEREC Omnicam (OC), 3M True Definition (TD), Heraeus Cara TRIOS (cT). The digital and conventional (gypsum) models were analyzed relative to the spheres. Linear distance and angle measurements between the spheres, as well as digital superimpositions of the spheres with the reference data set were executed. With regard to the distance measurements, CI showed the smallest deviations followed by intraoral scanners TD, cT and OC. A digital superimposition procedure yielded the same order for the outcomes: CI (15±4μm), TD (23±9μm), cT (37±14μm), OC (214±38μm). Angle measurements revealed the smallest deviation for TD (0.06°±0,07°) followed by CI (0.07°±0.07°), cT (0.13°±0.15°) and OC (0.28°±0.21°). The new measuring method is suitable for measuring the dimensional accuracy of full arch impressions intraorally. CI is still significantly more accurate than full arch scans with intraoral scanners in clinical use. Conventional full arch impressions with polyether impression materials are still more accurate than full arch digital impressions. Digital impression systems using powder application and active wavefront sampling technology achieve the most accurate results in comparison to other intraoral scanning systems (DRKS-ID: DRKS00009360, German Clinical Trials Register). Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparative Evaluation of Dimensional Accuracy of Elastomeric Impression Materials when Treated with Autoclave, Microwave, and Chemical Disinfection

PubMed Central

Kamble, Suresh S; Khandeparker, Rakshit Vijay; Somasundaram, P; Raghav, Shweta; Babaji, Rashmi P; Varghese, T Joju

2015-01-01

Background: Impression materials during impression procedure often get infected with various infectious diseases. Hence, disinfection of impression materials with various disinfectants is advised to protect the dental team. Disinfection can alter the dimensional accuracy of impression materials. The present study was aimed to evaluate the dimensional accuracy of elastomeric impression materials when treated with different disinfectants; autoclave, chemical, and microwave method. Materials and Methods: The impression materials used for the study were, dentsply aquasil (addition silicone polyvinylsiloxane syringe and putty), zetaplus (condensation silicone putty and light body), and impregum penta soft (polyether). All impressions were made according to manufacturer’s instructions. Dimensional changes were measured before and after different disinfection procedures. Result: Dentsply aquasil showed smallest dimensional change (−0.0046%) and impregum penta soft highest linear dimensional changes (−0.026%). All the tested elastomeric impression materials showed some degree of dimensional changes. Conclusion: The present study showed that all the disinfection procedures produce minor dimensional changes of impression material. However, it was within American Dental Association specification. Hence, steam autoclaving and microwave method can be used as an alternative method to chemical sterilization as an effective method. PMID:26435611

Insular and hippocampal contributions to remembering people with an impression of bad personality.

PubMed

Tsukiura, Takashi; Shigemune, Yayoi; Nouchi, Rui; Kambara, Toshimune; Kawashima, Ryuta

2013-06-01

Our impressions of other people are formed mainly from the two possible factors of facial attractiveness and trustworthiness. Previous studies have shown the importance of orbitofrontal-hippocampal interactions in the better remembering of attractive faces, and psychological data have indicated that faces giving an impression of untrustworthiness are remembered more accurately than those giving an impression of trustworthiness. However, the neural mechanisms of the latter effect are largely unknown. To investigate this issue, we investigated neural activities with event-related fMRI while the female participants rated their impressions of the personalities of men in terms of trustworthiness. After the rating, memory for faces was tested to identify successful encoding activity. As expected, faces that gave bad impressions were remembered better than those that gave neutral or good impressions. In fMRI data, right insular activity reflected an increasing function of bad impressions, and bilateral hippocampal activities predicted subsequent memory success. Additionally, correlation between these insular and hippocampal regions was significant only in the encoding of faces associated with a bad impression. Better memory for faces associated with an impression of bad personality could reflect greater interaction between the avoidance-related insular region and the encoding-related hippocampal region.

Insular and hippocampal contributions to remembering people with an impression of bad personality

PubMed Central

Shigemune, Yayoi; Nouchi, Rui; Kambara, Toshimune; Kawashima, Ryuta

2013-01-01

Our impressions of other people are formed mainly from the two possible factors of facial attractiveness and trustworthiness. Previous studies have shown the importance of orbitofrontal–hippocampal interactions in the better remembering of attractive faces, and psychological data have indicated that faces giving an impression of untrustworthiness are remembered more accurately than those giving an impression of trustworthiness. However, the neural mechanisms of the latter effect are largely unknown. To investigate this issue, we investigated neural activities with event-related fMRI while the female participants rated their impressions of the personalities of men in terms of trustworthiness. After the rating, memory for faces was tested to identify successful encoding activity. As expected, faces that gave bad impressions were remembered better than those that gave neutral or good impressions. In fMRI data, right insular activity reflected an increasing function of bad impressions, and bilateral hippocampal activities predicted subsequent memory success. Additionally, correlation between these insular and hippocampal regions was significant only in the encoding of faces associated with a bad impression. Better memory for faces associated with an impression of bad personality could reflect greater interaction between the avoidance-related insular region and the encoding-related hippocampal region. PMID:22349799

Antimicrobial effect of 4 disinfectants on alginate, polyether, and polyvinyl siloxane impression materials.

PubMed

Al-Jabrah, Osama; Al-Shumailan, Yousef; Al-Rashdan, Manhal

2007-01-01

Dental impressions often carry microorganisms that may cause cross infection from patients to dental staff. The aim of the current study was to determine the effectiveness of 4 different disinfectant solutions on 3 commonly used impression materials--alginate, polyether, and polyvinyl siloxane--to establish a protocol for disinfection of these impression materials after clinical exposure and prior to handling in the dental laboratory. A total of 45 impressions were taken from the maxillary dentate arches of 15 dental staff participants at the Department of Dentistry, Prince Rashid Hospital, Irbid, Jordan. For each participant, 3 successive impressions were recorded in the different impression materials. For each impression, 6 specimens were dissected from 6 different locations and exposed to 6 different regimens: 1 was left untreated, 1 was immersed in sterile water for 10 minutes to serve as a control, and the remaining 4 specimens were exposed to 4 different disinfection treatments (Dimenol, Perform-ID, MD 520, and Haz-tabs). Serial dilutions of the suspension were carried out and counted by the Miles-Misra technique (inoculation on Columbia blood agar for quantification). The dilutions were aerobically incubated at 37 degrees C for 48 hours. The disinfectants were able to completely eliminate microorganisms carried by the impressions. For those undisinfected specimens, the results showed that untreated alginate impressions appear to carry more microorganisms (P < .05) than the other 2 rubber impression materials used in the study. For those specimens immersed in sterile water for 10 minutes (control group), the number of microorganisms eliminated was increased from 62% to 90% compared to those left untreated. Impression materials may act as a vehicle for the transfer of microorganisms from the patient's mouth to dental personnel. Impressions should be disinfected to eliminate the risk of cross contamination.

Self-disinfecting Alginate vs Conventional Alginate: Effect on Surface Hardness of Gypsum Cast-An in vitro Study.

PubMed

Madhavan, Ranjith; George, Navia; Thummala, Niharika R; Ravi, S V; Nagpal, Ajay

2017-11-01

For the construction of any dental prosthesis, accurate impressions are necessary. Hence, we undertook the present study to evaluate and compare the surface hardness of gypsum casts poured from impressions made using conventional alginate and self-disinfecting alginate. A total of 30 impressions of stainless steel die were made, out of which 15 impressions were made with conventional alginate and 15 were made with self-disinfecting alginate and poured using Type III dental stone. Thirty stone specimens were subjected for hardness testing. Data were analyzed using independent samples t-test to compare the mean surface hardness. Difference in surface hardness was statistically insignificant (p > 0.05). Surface hardness of gypsum casts poured using impressions made from self-disinfecting alginate and conventional alginates were comparable. Self-disinfecting alginates may be employed in clinical practice as safe and effective materials to overcome the infection control issues without compromising on the properties of the material.

In Vitro Implant Impression Accuracy Using a New Photopolymerizing SDR Splinting Material.

PubMed

Di Fiore, Adolfo; Meneghello, Roberto; Savio, Gianpaolo; Sivolella, Stefano; Katsoulis, Joannis; Stellini, Edoardo

2015-10-01

The study aims to evaluate three-dimensionally (3D) the accuracy of implant impressions using a new resin splinting material, "Smart Dentin Replacement" (SDR). A titanium model of an edentulous mandible with six implant analogues was used as a master model and its dimensions measured with a coordinate measuring machine. Before the total 60 impressions were taken (open tray, screw-retained abutments, vinyl polysiloxane), they were divided in four groups: A (test): copings pick-up splinted with dental floss and fotopolymerizing SDR; B (test): see A, additionally sectioned and splinted again with SDR; C (control): copings pick-up splinted with dental floss and autopolymerizing Duralay® (Reliance Dental Mfg. Co., Alsip, IL, USA) acrylic resin; and D (control): see C, additionally sectioned and splinted again with Duralay. The impressions were measured directly with an optomechanical coordinate measuring machine and analyzed with a computer-aided design (CAD) geometric modeling software. The Wilcoxon matched-pair signed-rank test was used to compare groups. While there was no difference (p = .430) between the mean 3D deviations of the test groups A (17.5 μm) and B (17.4 μm), they both showed statistically significant differences (p < .003) compared with both control groups (C 25.0 μm, D 19.1 μm). Conventional impression techniques for edentulous jaws with multiple implants are highly accurate using the new fotopolymerizing splinting material SDR. Sectioning and rejoining of the SDR splinting had no impact on the impression accuracy. © 2015 Wiley Periodicals, Inc.

Intraoral scanning systems - a current overview.

PubMed

Zimmermann, M; Mehl, A; Mörmann, W H; Reich, S

2015-01-01

There is no doubt today about the possibilities and potential of digital impression-taking with the aid of intraoral optical impression systems, and the past few years have seen a considerable increase in the range of optical intraoral scanners available on the market. On the strength of numerous innovations and a wider range of indications in orthodontics and implantology, intraoral scanning systems appear to be a highly promising development for the future. Digital impression-taking with intraoral scanners has already shown itself in some respects to be clearly superior to conventional impression- taking. Particularly worthy of mention is the versatile integration of digital impressions into diagnostic and treatment concepts to provide a customizable healthcare solution for the patient. It remains exciting to look forward to future developments that will allow us to observe digital impression-taking--as with other digital applications already established in everyday life--becoming firmly established in the routine of dentistry and dental technology. This article presents an overview of the benefits and limitations of digital impression-taking using intraoral scanning systems, and includes a summary of all the relevant intraoral scanners available on the market at present.

Accuracy in Dental Medicine, A New Way to Measure Trueness and Precision

PubMed Central

Ender, Andreas; Mehl, Albert

2014-01-01

Reference scanners are used in dental medicine to verify a lot of procedures. The main interest is to verify impression methods as they serve as a base for dental restorations. The current limitation of many reference scanners is the lack of accuracy scanning large objects like full dental arches, or the limited possibility to assess detailed tooth surfaces. A new reference scanner, based on focus variation scanning technique, was evaluated with regards to highest local and general accuracy. A specific scanning protocol was tested to scan original tooth surface from dental impressions. Also, different model materials were verified. The results showed a high scanning accuracy of the reference scanner with a mean deviation of 5.3 ± 1.1 µm for trueness and 1.6 ± 0.6 µm for precision in case of full arch scans. Current dental impression methods showed much higher deviations (trueness: 20.4 ± 2.2 µm, precision: 12.5 ± 2.5 µm) than the internal scanning accuracy of the reference scanner. Smaller objects like single tooth surface can be scanned with an even higher accuracy, enabling the system to assess erosive and abrasive tooth surface loss. The reference scanner can be used to measure differences for a lot of dental research fields. The different magnification levels combined with a high local and general accuracy can be used to assess changes of single teeth or restorations up to full arch changes. PMID:24836007

The Trouble with Applicant Impression Management.

ERIC Educational Resources Information Center

Ralston, Steven M.; Kirkwood, William G.

1999-01-01

Suggests that applicant impression management (AIM) is more harmful to employment interviewing than is currently suspected. Offers a conceptual model of AIM that is consistent with employment interviewing practice. Presents and critiques three arguments used to defend AIM. Examines a model for helping employers conduct interviews that minimize the…

Effect of Storage Period on Dimensional Stability of Alginplus and Hydrogum 5

PubMed Central

Aalaei, Shima; Ganj-Khanloo, Rohollah

2017-01-01

Objectives: This study aimed to evaluate the effect of storage period on dimensional stability of Alginplus and Hydrogum 5. Materials and Methods: In this in vitro experimental study, 60 impressions were taken of an upper jaw typodont, including 10 impressions for each storage period to be tested (12 minutes, 24 and 120 hours) for each type of alginate. Then, the impressions were stored in an incubator with stable temperature and humidity, and poured using a type III dental stone. Subsequently, the mesiodistal dimension, occlusogingival height, and interarch distance were measured using a digital caliper with an accuracy of 0.01mm. The data were analyzed using ANOVA and t-test (P<0.05). Results: Alginplus and Hydrogum 5 impressions were not significantly different from the master model after 12 minutes and 24 hours in terms of dimensions (P>0.05). After 120 hours, all dimensions measured on casts were significantly different from those measured on the master model, except for the mesiodistal dimension of the Hydrogum 5 impressions. Conclusions: At a consistent temperature and humidity, the Alginplus and Hydrogum 5 impressions were dimensionally stable for at least 24 hours. PMID:28828015

Development and psychometric evaluation of a clinical global impression for schizoaffective disorder scale.

PubMed

Allen, Michael H; Daniel, David G; Revicki, Dennis A; Canuso, Carla M; Turkoz, Ibrahim; Fu, Dong-Jing; Alphs, Larry; Ishak, K Jack; Bartko, John J; Lindenmayer, Jean-Pierre

2012-01-01

The Clinical Global Impression for Schizoaffective Disorder scale is a new rating scale adapted from the Clinical Global Impression scale for use in patients with schizoaffective disorder. The psychometric characteristics of the Clinical Global Impression for Schizoaffective Disorder are described. Content validity was assessed using an investigator questionnaire. Inter-rater reliability was determined with 12 sets of videotaped interviews rated independently by two trained individuals. Test-retest reliability was assessed using 30 randomly selected raters from clinical trials who evaluated the same videos on separate occasions two weeks apart. Convergent and divergent validity and effect size were evaluated by comparing scores between the Clinical Global Impression for Schizoaffective Disorder and the Positive and Negative Syndrome Scale, 21-item Hamilton Rating Scale for Depression, and Young Mania Rating Scale scales using pooled patient data from two clinical trials. Clinical Global Impression for Schizoaffective Disorder scores were then linked to corresponding Positive and Negative Syndrome Scale scores. Content validity was strong. Inter-rater agreement was good to excellent for most scales and subscales (intra-class correlation coefficient ≥ 0.50). Test-retest showed good reproducibility, with intraclass correlation coefficients ranging from 0.444 to 0.898. Spearman correlations between Clinical Global Impression for Schizoaffective Disorder domains and corresponding symptom scales were 0.60 or greater, and effect sizes for Clinical Global Impression for Schizoaffective Disorder overall and domain scores were similar to Positive and Negative Syndrome Scale Young Mania Rating Scale, and 21-item Hamilton Rating Scale for Depression scores. Raters anticipated that the scale might be less effective in distinguishing negative from depressive symptoms, and, in fact, the results here may reflect that clinical reality. Multiple lines of evidence support the reliability and validity of the Clinical Global Impression for Schizoaffective Disorder for studies in schizoaffective disorder.

Drying time of tray adhesive for adequate tensile bond strength between polyvinylsiloxane impression and tray resin material.

PubMed

Yi, Myong-Hee; Shim, Joon-Sung; Lee, Keun-Woo; Chung, Moon-Kyu

2009-07-01

Use of custom tray and tray adhesive is clinically recommended for elastomeric impression material. However there is not clear mention of drying time of tray adhesive in achieving appropriate bonding strength of tray material and impression material. This study is to investigate an appropriate drying time of tray adhesives by evaluating tensile bonding strength between two types of polyvinylsiloxane impression materials and resin tray, according to various drying time intervals of tray adhesives, and with different manufacturing company combination of impression material and tray adhesive. Adhesives used in this study were Silfix (Dentsply Caulk, Milford, Del, USA) and VPS Tray Adhesive (3M ESPE, Seefeld, Germany) and impression materials were Aquasil Ultra (monophase regular set, Dentsply Caulk, Milford, Del, USA) and Imprint II Garant (regular body, 3M ESPE, Seefeld, Germany). They were used combinations from the same manufacture and exchanged combinations of the two. The drying time was designed to air dry, 5 minutes, 10 minutes, 15 minutes, 20 minutes, and 25 minutes. Total 240 of test specimens were prepared by auto-polymerizing tray material (Instant Tray Mix, Lang, Wheeling, Il, USA) with 10 specimens in each group. The specimens were placed in the Universal Testing machine (Instron, model 3366, Instron Corp, University avenue, Nowood, MA, USA) to perform the tensile test (cross head speed 5 mm/min). The statistically efficient drying time was evaluated through ANOVA and Scheffe test. All the tests were performed at 95% confidence level. The results revealed that at least 10 minutes is needed for Silfix-Aquasil, and 15 minutes for VPS Tray Adhesive-Imprint II, to attain an appropriate tensile bonding strength. VPS Tray Adhesive-Imprint II had a superior tensile bonding strength when compared to Silfix-Aquasil over 15 minutes. Silfix-Aquasil had a superior bonding strength to VPS Tray Adhesive-Aquasil, and VPS Tray Adhesive-Imprint II had a superior tensile bonding strength to Silfix-Imprint II at all drying periods. Significant increase in tensile bonding strength with Silfix-Aquasil and VPS Tray adhesive-Imprint II combination until 10 and 15 minutes respectively. Tray adhesive-impression material combination from the same company presented higher tensile bonding strength at all drying time intervals than when using tray adhesive-impression material of different manufactures.

Social desirability scales as indicators of self-enhancement and impression management.

PubMed

Parmač Kovačić, Maja; Galić, Zvonimir; Jerneić, Željko

2014-01-01

This article presents 2 studies testing Paulhus's (2002) assumption that unconscious self-enhancement and conscious impression management represent separate processes of socially desirable responding (SDR) that can be observed within 2 content domains (egoistic and moralistic bias). In Study 1, we devised egoistic and moralistic SDR scales intended to measure self-enhancement in honest responding and impression management under demands for positive self-presentation. In Study 2, we correlated scores on these scales with external indicators of self-enhancement and impression management. In honest responding, both SDR scales most strongly correlated with self-enhancement indicators, whereas under demands for positive self-presentation they correlated more strongly with external measures of impression management.

Accuracy of implant impressions without impression copings: a three-dimensional analysis.

PubMed

Kwon, Joo-Hyun; Son, Yong-Ha; Han, Chong-Hyun; Kim, Sunjai

2011-06-01

Implant impressions without impression copings can be used for cement-retained implant restorations. A comparison of the accuracy of implant impressions with and without impression copings is needed. The purpose of this study was to evaluate and compare the dimensional accuracy of implant definitive casts that are fabricated by implant impressions with and without impression copings. An acrylic resin maxillary model was fabricated, and 3 implant replicas were secured in the right second premolar, first, and second molars. Two impression techniques were used to fabricate definitive casts (n=10). For the coping group (Group C), open tray impression copings were used for the final impressions. For the no-coping group (Group NC), cementable abutments were connected to the implant replicas, and final impressions were made assuming the abutments were prepared teeth. Computerized calculation of the centroids and long axes of the implant or stone abutment replicas was performed. The Mann-Whitney U test analyzed the amount of linear and rotational distortion between groups (α =.05). At the first molar site, Group NC showed significantly greater linear distortion along the Y-axis, with a small difference between the groups (Group C, 7.8 ± 7.4 μm; Group NC, 19.5 ± 12.2). At the second molar site, increased distortion was noted in Group NC for every linear and rotational variable, except for linear distortion along the Z-axis. Implant impression with open tray impression copings produced more accurate definitive casts than those fabricated without impression copings, especially those with greater inter-abutment distance. Copyright © 2011 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Accuracy of five implant impression technique: effect of splinting materials and methods

PubMed Central

Cho, Sung-Bum

2011-01-01

PURPOSE The aim of this study was to evaluate the effect of dimensional stability of splinting material on the accuracy of master casts. MATERIALS AND METHODS A stainless steel metal model with 6 implants embedded was used as a master model. Implant level impressions were made after square impression copings were splinted using 5 different techniques as follows. (1) Splinted with autopolymerizing resin and sectioned, reconnected to compensate polymerization shrinkage before the impression procedure. (2) Splinted with autopolymerizing resin just before impression procedure. (3) Primary impression made with impression plaster and secondary impression were made over with polyether impression material. (4) Splinted with impression plaster. (5) Splinted with VPS bite registration material. From master model, 5 impressions and 5 experimental casts, total 25 casts were made for each of 5 splinting methods. The distortion values of each splinting methods were measured using coordinate measuring machine, capable of recordings in the x-, y-, z-axes. A one-way analysis of variance (ANOVA) at a confidence level of 95% was used to evaluate the data and Tukey's studentized range test was used to determine significant differences between the groups. RESULTS Group 1 showed best accuracy followed by Group 3 & 4. Group 2 and 5 showed relatively larger distortion value than other groups. No significant difference was found between group 3, 4, 5 in x-axis, group 2, 3, 4 in y-axis and group 1, 3, 4, 5 in z-axis (P<.0001). CONCLUSION Both Splinting impression copings with autopolymerizing resin following compensation of polymerization shrinkage and splinting method with impression plaster can enhance the accuracy of master cast and impression plaster can be used simple and effective splinting material for implant impression procedure. PMID:22259700

Giving the wrong impression: food and beverage brand impressions delivered to youth through popular movies.

PubMed

Skatrud-Mickelson, Monica; Adachi-Mejia, Anna M; MacKenzie, Todd A; Sutherland, Lisa A

2012-06-01

Marketing on television showcases less-healthful options, with emerging research suggesting movies promote similar products. Given the obesity epidemic, understanding advertising to youth should be a public health imperative. The objective of this study was to estimate youth impressions to food and beverages delivered through movies. Impressions were calculated by dividing US receipts annually into average movie ticket prices, then multiplying this by the number of brand appearances. Examination by ratings, product types and ages were conducted by Spearman rank correlation coefficient tests. Youth in the USA saw over 3 billion food, beverage or food-retail establishment (FRE) impressions on average, annually from 1996 to 2005. Those aged 12-18 viewed over half of all impressions, with PG-13-rated movies containing 61.5% of impressions. There were no significant trends in brand appearances by food, beverage or FRE impressions over the decade, although there was a decreasing trend in R-rated impressions for both foods (P< 0.01) and beverages (P< 0.01), but not FREs (P= 0.08). Movies promote billions of food and beverage impressions annually to youth. Given the public health crisis of obesity, future research should further investigate these trends, as well as the potential association of these unhealthy exposures in youth.

Giving the wrong impression: food and beverage brand impressions delivered to youth through popular movies

PubMed Central

Skatrud-Mickelson, Monica; Adachi-Mejia, Anna M.; MacKenzie, Todd A.; Sutherland, Lisa A.

2012-01-01

Background Marketing on television showcases less-healthful options, with emerging research suggesting movies promote similar products. Given the obesity epidemic, understanding advertising to youth should be a public health imperative. The objective of this study was to estimate youth impressions to food and beverages delivered through movies. Methods Impressions were calculated by dividing US receipts annually into average movie ticket prices, then multiplying this by the number of brand appearances. Examination by ratings, product types and ages were conducted by Spearman rank correlation coefficient tests. Results Youth in the USA saw over 3 billion food, beverage or food–retail establishment (FRE) impressions on average, annually from 1996 to 2005. Those aged 12–18 viewed over half of all impressions, with PG-13-rated movies containing 61.5% of impressions. There were no significant trends in brand appearances by food, beverage or FRE impressions over the decade, although there was a decreasing trend in R-rated impressions for both foods (P< 0.01) and beverages (P< 0.01), but not FREs (P= 0.08). Conclusions Movies promote billions of food and beverage impressions annually to youth. Given the public health crisis of obesity, future research should further investigate these trends, as well as the potential association of these unhealthy exposures in youth. PMID:22076600

Accuracy of the One-Stage and Two-Stage Impression Techniques: A Comparative Analysis

PubMed Central

Jamshidy, Ladan; Faraji, Payam; Sharifi, Roohollah

2016-01-01

Introduction. One of the main steps of impression is the selection and preparation of an appropriate tray. Hence, the present study aimed to analyze and compare the accuracy of one- and two-stage impression techniques. Materials and Methods. A resin laboratory-made model, as the first molar, was prepared by standard method for full crowns with processed preparation finish line of 1 mm depth and convergence angle of 3-4°. Impression was made 20 times with one-stage technique and 20 times with two-stage technique using an appropriate tray. To measure the marginal gap, the distance between the restoration margin and preparation finish line of plaster dies was vertically determined in mid mesial, distal, buccal, and lingual (MDBL) regions by a stereomicroscope using a standard method. Results. The results of independent test showed that the mean value of the marginal gap obtained by one-stage impression technique was higher than that of two-stage impression technique. Further, there was no significant difference between one- and two-stage impression techniques in mid buccal region, but a significant difference was reported between the two impression techniques in MDL regions and in general. Conclusion. The findings of the present study indicated higher accuracy for two-stage impression technique than for the one-stage impression technique. PMID:28003824

Accuracy of the One-Stage and Two-Stage Impression Techniques: A Comparative Analysis.

PubMed

Jamshidy, Ladan; Mozaffari, Hamid Reza; Faraji, Payam; Sharifi, Roohollah

2016-01-01

Introduction . One of the main steps of impression is the selection and preparation of an appropriate tray. Hence, the present study aimed to analyze and compare the accuracy of one- and two-stage impression techniques. Materials and Methods . A resin laboratory-made model, as the first molar, was prepared by standard method for full crowns with processed preparation finish line of 1 mm depth and convergence angle of 3-4°. Impression was made 20 times with one-stage technique and 20 times with two-stage technique using an appropriate tray. To measure the marginal gap, the distance between the restoration margin and preparation finish line of plaster dies was vertically determined in mid mesial, distal, buccal, and lingual (MDBL) regions by a stereomicroscope using a standard method. Results . The results of independent test showed that the mean value of the marginal gap obtained by one-stage impression technique was higher than that of two-stage impression technique. Further, there was no significant difference between one- and two-stage impression techniques in mid buccal region, but a significant difference was reported between the two impression techniques in MDL regions and in general. Conclusion . The findings of the present study indicated higher accuracy for two-stage impression technique than for the one-stage impression technique.

Investigation of the effects of storage time on the dimensional accuracy of impression materials using cone beam computed tomography

PubMed Central

2016-01-01

PURPOSE The storage conditions of impressions affect the dimensional accuracy of the impression materials. The aim of the study was to assess the effects of storage time on dimensional accuracy of five different impression materials by cone beam computed tomography (CBCT). MATERIALS AND METHODS Polyether (Impregum), hydrocolloid (Hydrogum and Alginoplast), and silicone (Zetaflow and Honigum) impression materials were used for impressions taken from an acrylic master model. The impressions were poured and subjected to four different storage times: immediate use, and 1, 3, and 5 days of storage. Line 1 (between right and left first molar mesiobuccal cusp tips) and Line 2 (between right and left canine tips) were measured on a CBCT scanned model, and time dependent mean differences were analyzed by two-way univariate and Duncan's test (α=.05). RESULTS For Line 1, the total mean difference of Impregum and Hydrogum were statistically different from Alginoplast (P<.05), while Zetaflow and Honigum had smaller discrepancies. Alginoplast resulted in more difference than the other impressions (P<.05). For Line 2, the total mean difference of Impregum was statistically different from the other impressions. Significant differences were observed in Line 1 and Line 2 for the different storage periods (P<.05). CONCLUSION The dimensional accuracy of impression material is clinically acceptable if the impression material is stored in suitable conditions. PMID:27826388

Investigation of the effects of storage time on the dimensional accuracy of impression materials using cone beam computed tomography.

PubMed

Alkurt, Murat; Yeşıl Duymus, Zeynep; Dedeoglu, Numan

2016-10-01

The storage conditions of impressions affect the dimensional accuracy of the impression materials. The aim of the study was to assess the effects of storage time on dimensional accuracy of five different impression materials by cone beam computed tomography (CBCT). Polyether (Impregum), hydrocolloid (Hydrogum and Alginoplast), and silicone (Zetaflow and Honigum) impression materials were used for impressions taken from an acrylic master model. The impressions were poured and subjected to four different storage times: immediate use, and 1, 3, and 5 days of storage. Line 1 (between right and left first molar mesiobuccal cusp tips) and Line 2 (between right and left canine tips) were measured on a CBCT scanned model, and time dependent mean differences were analyzed by two-way univariate and Duncan's test (α=.05). For Line 1, the total mean difference of Impregum and Hydrogum were statistically different from Alginoplast ( P <.05), while Zetaflow and Honigum had smaller discrepancies. Alginoplast resulted in more difference than the other impressions ( P <.05). For Line 2, the total mean difference of Impregum was statistically different from the other impressions. Significant differences were observed in Line 1 and Line 2 for the different storage periods ( P <.05). The dimensional accuracy of impression material is clinically acceptable if the impression material is stored in suitable conditions.

Impression management and food intake. Current directions in research.

PubMed

Vartanian, Lenny R

2015-03-01

This paper reviews recent research on consumption stereotypes (judgments of others based on what they eat) and impression management (modifying one's eating behavior in order to create a particular impression). A major recent focus in the literature has been on masculinity and meat eating, with research showing that meat is strongly associated with masculinity, and that individuals who follow a meat-based diet are perceived as more masculine than are individuals who follow a vegetarian diet. Although direct evidence for impression management through food intake remains sparse, a number of methodological approaches (including priming techniques and ecological valid assessments) are described that could be used in future research to identify the motives underlying people's eating behavior. Consumption stereotypes and impression management may be important influences on people's eating behavior, but the complexities of how, when, and for whom these factors influence food intake are still not well understood. Copyright © 2014 Elsevier Ltd. All rights reserved.

Comparison of intraoral scanning and conventional impression techniques using 3-dimensional superimposition.

PubMed

Rhee, Ye-Kyu; Huh, Yoon-Hyuk; Cho, Lee-Ra; Park, Chan-Jin

2015-12-01

The aim of this study is to evaluate the appropriate impression technique by analyzing the superimposition of 3D digital model for evaluating accuracy of conventional impression technique and digital impression. Twenty-four patients who had no periodontitis or temporomandibular joint disease were selected for analysis. As a reference model, digital impressions with a digital impression system were performed. As a test models, for conventional impression dual-arch and full-arch, impression techniques utilizing addition type polyvinylsiloxane for fabrication of cast were applied. 3D laser scanner is used for scanning the cast. Each 3 pairs for 25 STL datasets were imported into the inspection software. The three-dimensional differences were illustrated in a color-coded map. For three-dimensional quantitative analysis, 4 specified contact locations(buccal and lingual cusps of second premolar and molar) were established. For twodimensional quantitative analysis, the sectioning from buccal cusp to lingual cusp of second premolar and molar were acquired depending on the tooth axis. In color-coded map, the biggest difference between intraoral scanning and dual-arch impression was seen (P<.05). In three-dimensional analysis, the biggest difference was seen between intraoral scanning and dual-arch impression and the smallest difference was seen between dual-arch and full-arch impression. The two- and three-dimensional deviations between intraoral scanner and dual-arch impression was bigger than full-arch and dual-arch impression (P<.05). The second premolar showed significantly bigger three-dimensional deviations than the second molar in the three-dimensional deviations (P>.05).

Comparison of intraoral scanning and conventional impression techniques using 3-dimensional superimposition

PubMed Central

Rhee, Ye-Kyu

2015-01-01

PURPOSE The aim of this study is to evaluate the appropriate impression technique by analyzing the superimposition of 3D digital model for evaluating accuracy of conventional impression technique and digital impression. MATERIALS AND METHODS Twenty-four patients who had no periodontitis or temporomandibular joint disease were selected for analysis. As a reference model, digital impressions with a digital impression system were performed. As a test models, for conventional impression dual-arch and full-arch, impression techniques utilizing addition type polyvinylsiloxane for fabrication of cast were applied. 3D laser scanner is used for scanning the cast. Each 3 pairs for 25 STL datasets were imported into the inspection software. The three-dimensional differences were illustrated in a color-coded map. For three-dimensional quantitative analysis, 4 specified contact locations(buccal and lingual cusps of second premolar and molar) were established. For twodimensional quantitative analysis, the sectioning from buccal cusp to lingual cusp of second premolar and molar were acquired depending on the tooth axis. RESULTS In color-coded map, the biggest difference between intraoral scanning and dual-arch impression was seen (P<.05). In three-dimensional analysis, the biggest difference was seen between intraoral scanning and dual-arch impression and the smallest difference was seen between dual-arch and full-arch impression. CONCLUSION The two- and three-dimensional deviations between intraoral scanner and dual-arch impression was bigger than full-arch and dual-arch impression (P<.05). The second premolar showed significantly bigger three-dimensional deviations than the second molar in the three-dimensional deviations (P>.05). PMID:26816576

In vivo evaluation of inter-operator reproducibility of digital dental and conventional impression techniques.

PubMed

Kamimura, Emi; Tanaka, Shinpei; Takaba, Masayuki; Tachi, Keita; Baba, Kazuyoshi

2017-01-01

The aim of this study was to evaluate and compare the inter-operator reproducibility of three-dimensional (3D) images of teeth captured by a digital impression technique to a conventional impression technique in vivo. Twelve participants with complete natural dentition were included in this study. A digital impression of the mandibular molars of these participants was made by two operators with different levels of clinical experience, 3 or 16 years, using an intra-oral scanner (Lava COS, 3M ESPE). A silicone impression also was made by the same operators using the double mix impression technique (Imprint3, 3M ESPE). Stereolithography (STL) data were directly exported from the Lava COS system, while STL data of a plaster model made from silicone impression were captured by a three-dimensional (3D) laboratory scanner (D810, 3shape). The STL datasets recorded by two different operators were compared using 3D evaluation software and superimposed using the best-fit-algorithm method (least-squares method, PolyWorks, InnovMetric Software) for each impression technique. Inter-operator reproducibility as evaluated by average discrepancies of corresponding 3D data was compared between the two techniques (Wilcoxon signed-rank test). The visual inspection of superimposed datasets revealed that discrepancies between repeated digital impression were smaller than observed with silicone impression. Confirmation was forthcoming from statistical analysis revealing significantly smaller average inter-operator reproducibility using a digital impression technique (0.014± 0.02 mm) than when using a conventional impression technique (0.023 ± 0.01 mm). The results of this in vivo study suggest that inter-operator reproducibility with a digital impression technique may be better than that of a conventional impression technique and is independent of the clinical experience of the operator.

Impact of Internet Images: Impression-Formation Effects of University Web Site Images

ERIC Educational Resources Information Center

Ramasubramanian, Srividya; Gyure, James F.; Mursi, Nasreen M.

2002-01-01

Institutions of higher education are increasingly becoming dependent on Web-based marketing to reach out to their target audiences. The current empirical study examines the types of impressions formed by prospective students based on exposure to different university Web site images. A between-subjects experiment was conducted using four identical…

Similarity to the self influences cortical recruitment during impression formation

PubMed Central

Leshikar, Eric D.; Cassidy, Brittany S.; Gutchess, Angela H.

2015-01-01

Prior work has shown that whether or not someone is similar to the self influences person memory—a type of self-reference effect for others. In this study, we were interested in understanding the neural regions supporting the generation of impressions and subsequent memory for targets who vary in similarity to the self. Participants underwent fMRI scanning while forming positive or negative impressions of face-behavior pairs. We tested participants’ memory for their generated impressions, and then back-sorted the impression trials (encoding) into different levels of self-similarity (high, medium, low) using a self-similarity post-test that came after recognition. Extending prior behavioral work, our data confirmed our hypothesis that memory would be highest for self-similar others and lowest for self-dissimilar others. Dorsal anterior cingulate cortex (dACC) activity increased with self-similarity (high > medium > low) to targets, regardless of later memory for them. An analysis of regions supporting impression memory revealed a double dissociation within medial temporal lobe regions: for similar others, amygdala recruitment supported memory, whereas for dissimilar others, hippocampal activation supported memory. These results suggest that self-similarity influences evaluation and memory for targets, but also affects the underlying neural resources engaged when thinking about others who vary in self-similarity. PMID:26558615

A novel method for the photographic recovery of fingermark impressions from ammunition cases using digital imaging.

PubMed

Porter, Glenn; Ebeyan, Robert; Crumlish, Charles; Renshaw, Adrian

2015-03-01

The photographic preservation of fingermark impression evidence found on ammunition cases remains problematic due to the cylindrical shape of the deposition substrate preventing complete capture of the impression in a single image. A novel method was developed for the photographic recovery of fingermarks from curved surfaces using digital imaging. The process involves the digital construction of a complete impression image made from several different images captured from multiple camera perspectives. Fingermark impressions deposited onto 9-mm and 0.22-caliber brass cartridge cases and a plastic 12-gauge shotgun shell were tested using various image parameters, including digital stitching method, number of images per 360° rotation of shell, image cropping, and overlap. The results suggest that this method may be successfully used to recover fingermark impression evidence from the surfaces of ammunition cases or other similar cylindrical surfaces. © 2014 American Academy of Forensic Sciences.

Corrosion Assessment of Steel Bars Used in Reinforced Concrete Structures by Means of Eddy Current Testing

PubMed Central

de Alcantara, Naasson P.; da Silva, Felipe M.; Guimarães, Mateus T.; Pereira, Matheus D.

2015-01-01

This paper presents a theoretical and experimental study on the use of Eddy Current Testing (ECT) to evaluate corrosion processes in steel bars used in reinforced concrete structures. The paper presents the mathematical basis of the ECT sensor built by the authors; followed by a finite element analysis. The results obtained in the simulations are compared with those obtained in experimental tests performed by the authors. Effective resistances and inductances; voltage drops and phase angles of wound coil are calculated using both; simulated and experimental data; and demonstrate a strong correlation. The production of samples of corroded steel bars; by using an impressed current technique is also presented. The authors performed experimental tests in the laboratory using handmade sensors; and the corroded samples. In the tests four gauges; with five levels of loss-of-mass references for each one were used. The results are analyzed in the light of the loss-of-mass and show a strong linear behavior for the analyzed parameters. The conclusions emphasize the feasibility of the proposed technique and highlight opportunities for future works. PMID:26712754

Corrosion Assessment of Steel Bars Used in Reinforced Concrete Structures by Means of Eddy Current Testing.

PubMed

de Alcantara, Naasson P; da Silva, Felipe M; Guimarães, Mateus T; Pereira, Matheus D

2015-12-24

This paper presents a theoretical and experimental study on the use of Eddy Current Testing (ECT) to evaluate corrosion processes in steel bars used in reinforced concrete structures. The paper presents the mathematical basis of the ECT sensor built by the authors; followed by a finite element analysis. The results obtained in the simulations are compared with those obtained in experimental tests performed by the authors. Effective resistances and inductances; voltage drops and phase angles of wound coil are calculated using both; simulated and experimental data; and demonstrate a strong correlation. The production of samples of corroded steel bars; by using an impressed current technique is also presented. The authors performed experimental tests in the laboratory using handmade sensors; and the corroded samples. In the tests four gauges; with five levels of loss-of-mass references for each one were used. The results are analyzed in the light of the loss-of-mass and show a strong linear behavior for the analyzed parameters. The conclusions emphasize the feasibility of the proposed technique and highlight opportunities for future works.

Forming first impressions of others in schizophrenia: impairments in fast processing and in use of spatial frequency information.

PubMed

Vakhrusheva, J; Zemon, V; Bar, M; Weiskopf, N G; Tremeau, F; Petkova, E; Su, Z; Abeles, I Y; Butler, P D

2014-12-01

Individuals form first impressions of others all the time, which affects their social functioning. Typical adults form threat impressions in faces with neutral expressions quickly, requiring less than 40 ms. These impressions appear to be mediated by low spatial frequency (LSF) content in the images. Little is known, however, about mechanisms of first impression formation in schizophrenia. The current study investigated how quickly individuals with schizophrenia can form consistent impressions of threat compared with controls and explored the mechanisms involved. Patients and controls were presented intact, LSF- or high spatial frequency (HSF)-filtered faces with durations that varied from 39 to 1703 ms and were asked to rate how threatening each face was on a scale from 1 to 5. In order to assess the speed of impression formation for intact faces, correlations were calculated for ratings made at each duration compared to a reference duration of 1703 ms for each group. Controls demonstrated a significant relation for intact faces presented for 39 ms, whereas patients required 390 ms to demonstrate a significant relation with the reference duration. For controls, LSFs primarily contributed to the formation of consistent threat impressions at 39 ms, whereas patients showed a trend for utilizing both LSF and HSF information to form consistent threat impressions at 390 ms. Results indicate that individuals with schizophrenia require a greater integration time to form a stable "first impression" of threat, which may be related to the need to utilize compensatory mechanisms such as HSF, as well as LSF, information. Copyright © 2014 Elsevier B.V. All rights reserved.

Effect of variation of impression material combinations, dual arch tray types, and sequence of pour on the accuracy of working dies: "An in vitro study".

PubMed

Reddy, Nagam Raja; Reddy, Jakranpally Sathya; Padmaja, Bramha Josyula Indira; Reddy, Budigi Madan Mohan; Sunil, Motupalli; Reddy, Bommireddy Tejeswar

2016-01-01

To evaluate the accuracy of dies made from dual arch impressions using different sectional dual arch trays, combinations of elastomeric impression materials, and the sequence of pour of dies. The dual arch impression materials were grouped into three groups depending on the combination of impression materials used and each group is subdivided into four subgroups. A sample size of 8 in each subgroup yielding a total 96 impressions will be made into three groups of 32 each (Group I, II, and III). Group I constitute impressions made using monophase (M) impression material, Group II constitute impressions made using combination of heavy body and light body (HL), and Group III constitute impressions made using combination of putty and light body (PL). Dies obtained were evaluated with a travelling microscope to measure the buccolingual width of the tooth at the margin by using the sharp corners of the notches as reference points. Descriptive analysis namely mean and standard deviation, one-way analysis of variance test. The results obtained in this study indicate that though not statistically significant, the metal dual arch trays performed better when compared to the plastic trays in reproducing die dimensions. From the results obtained, dies poured from combination of heavy body and light body impressions using plastic or metal dual arch trays showed least variation in bucco-lingual dimension from master model.

Effect of variation of impression material combinations, dual arch tray types, and sequence of pour on the accuracy of working dies: “An in vitro study”

PubMed Central

Reddy, Nagam Raja; Reddy, Jakranpally Sathya; Padmaja, Bramha Josyula Indira; Reddy, Budigi Madan Mohan; Sunil, Motupalli; Reddy, Bommireddy Tejeswar

2016-01-01

Aims: To evaluate the accuracy of dies made from dual arch impressions using different sectional dual arch trays, combinations of elastomeric impression materials, and the sequence of pour of dies. Subjects and Methods: The dual arch impression materials were grouped into three groups depending on the combination of impression materials used and each group is subdivided into four subgroups. A sample size of 8 in each subgroup yielding a total 96 impressions will be made into three groups of 32 each (Group I, II, and III). Group I constitute impressions made using monophase (M) impression material, Group II constitute impressions made using combination of heavy body and light body (HL), and Group III constitute impressions made using combination of putty and light body (PL). Dies obtained were evaluated with a travelling microscope to measure the buccolingual width of the tooth at the margin by using the sharp corners of the notches as reference points. Statistical Analysis Used: Descriptive analysis namely mean and standard deviation, one-way analysis of variance test. Results: The results obtained in this study indicate that though not statistically significant, the metal dual arch trays performed better when compared to the plastic trays in reproducing die dimensions. Conclusions: From the results obtained, dies poured from combination of heavy body and light body impressions using plastic or metal dual arch trays showed least variation in bucco-lingual dimension from master model. PMID:27141172

In vivo precision of conventional and digital methods of obtaining complete-arch dental impressions.

PubMed

Ender, Andreas; Attin, Thomas; Mehl, Albert

2016-03-01

Digital impression systems have undergone significant development in recent years, but few studies have investigated the accuracy of the technique in vivo, particularly compared with conventional impression techniques. The purpose of this in vivo study was to investigate the precision of conventional and digital methods for complete-arch impressions. Complete-arch impressions were obtained using 5 conventional (polyether, POE; vinylsiloxanether, VSE; direct scannable vinylsiloxanether, VSES; digitized scannable vinylsiloxanether, VSES-D; and irreversible hydrocolloid, ALG) and 7 digital (CEREC Bluecam, CER; CEREC Omnicam, OC; Cadent iTero, ITE; Lava COS, LAV; Lava True Definition Scanner, T-Def; 3Shape Trios, TRI; and 3Shape Trios Color, TRC) techniques. Impressions were made 3 times each in 5 participants (N=15). The impressions were then compared within and between the test groups. The cast surfaces were measured point-to-point using the signed nearest neighbor method. Precision was calculated from the (90%-10%)/2 percentile value. The precision ranged from 12.3 μm (VSE) to 167.2 μm (ALG), with the highest precision in the VSE and VSES groups. The deviation pattern varied distinctly according to the impression method. Conventional impressions showed the highest accuracy across the complete dental arch in all groups, except for the ALG group. Conventional and digital impression methods differ significantly in the complete-arch accuracy. Digital impression systems had higher local deviations within the complete arch cast; however, they achieve equal and higher precision than some conventional impression materials. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Evaluation of the Accuracy of Conventional and Digital Impression Techniques for Implant Restorations.

PubMed

Moura, Renata Vasconcellos; Kojima, Alberto Noriyuki; Saraceni, Cintia Helena Coury; Bassolli, Lucas; Balducci, Ivan; Özcan, Mutlu; Mesquita, Alfredo Mikail Melo

2018-05-01

The increased use of CAD systems can generate doubt about the accuracy of digital impressions for angulated implants. The aim of this study was to evaluate the accuracy of different impression techniques, two conventional and one digital, for implants with and without angulation. We used a polyurethane cast that simulates the human maxilla according to ASTM F1839, and 6 tapered implants were installed with external hexagonal connections to simulate tooth positions 17, 15, 12, 23, 25, and 27. Implants 17 and 23 were placed with 15° of mesial angulation and distal angulation, respectively. Mini cone abutments were installed on these implants with a metal strap 1 mm in height. Conventional and digital impression procedures were performed on the maxillary master cast, and the implants were separated into 6 groups based on the technique used and measurement type: G1 - control, G2 - digital impression, G3 - conventional impression with an open tray, G4 - conventional impression with a closed tray, G5 - conventional impression with an open tray and a digital impression, and G6 - conventional impression with a closed tray and a digital impression. A statistical analysis was performed using two-way repeated measures ANOVA to compare the groups, and a Kruskal-Wallis test was conducted to analyze the accuracy of the techniques. No significant difference in the accuracy of the techniques was observed between the groups. Therefore, no differences were found among the conventional impression and the combination of conventional and digital impressions, and the angulation of the implants did not affect the accuracy of the techniques. All of the techniques exhibited trueness and had acceptable precision. The variation of the angle of the implants did not affect the accuracy of the techniques. © 2018 by the American College of Prosthodontists.

Evaluation of accuracy of complete-arch multiple-unit abutment-level dental implant impressions using different impression and splinting materials.

PubMed

Buzayan, Muaiyed; Baig, Mirza Rustum; Yunus, Norsiah

2013-01-01

This in vitro study evaluated the accuracy of multiple-unit dental implant casts obtained from splinted or nonsplinted direct impression techniques using various splinting materials by comparing the casts to the reference models. The effect of two different impression materials on the accuracy of the implant casts was also evaluated for abutment-level impressions. A reference model with six internal-connection implant replicas placed in the completely edentulous mandibular arch and connected to multi-base abutments was fabricated from heat-curing acrylic resin. Forty impressions of the reference model were made, 20 each with polyether (PE) and polyvinylsiloxane (PVS) impression materials using the open tray technique. The PE and PVS groups were further subdivided into four subgroups of five each on the bases of splinting type: no splinting, bite registration PE, bite registration addition silicone, or autopolymerizing acrylic resin. The positional accuracy of the implant replica heads was measured on the poured casts using a coordinate measuring machine to assess linear differences in interimplant distances in all three axes. The collected data (linear and three-dimensional [3D] displacement values) were compared with the measurements calculated on the reference resin model and analyzed with nonparametric tests (Kruskal-Wallis and Mann-Whitney). No significant differences were found between the various splinting groups for both PE and PVS impression materials in terms of linear and 3D distortions. However, small but significant differences were found between the two impression materials (PVS, 91 μm; PE, 103 μm) in terms of 3D discrepancies, irrespective of the splinting technique employed. Casts obtained from both impression materials exhibited differences from the reference model. The impression material influenced impression inaccuracy more than the splinting material for multiple-unit abutment-level impressions.

Effect of different impression materials and techniques on the dimensional accuracy of implant definitive casts.

PubMed

Ebadian, Behnaz; Rismanchian, Mansor; Dastgheib, Badrosadat; Bajoghli, Farshad

2015-01-01

Different factors such as impression techniques and materials can affect the passive fit between the superstructure and implant. The aim of this study was to determine the effect of different impression materials and techniques on the dimensional accuracy of implant definitive casts. Four internal hex implants (Biohorizons Ø4 mm) were placed on a metal maxillary model perpendicular to the horizontal plane in maxillary lateral incisors, right canine and left first premolar areas. Three impression techniques including open tray, closed tray using ball top screw abutments and closed tray using short impression copings and two impression materials (polyether and polyvinyl siloxane) were evaluated (n = 60). The changes in distances between implant analogues in mediolateral (x) and anteroposterior (y) directions and analogue angles in x/z and y/z directions in the horizontal plane on the definitive casts were measured by coordinate measuring machine. The data were analyzed by multivariate two-way analysis of variance and one sample t-test (α = 0.05). No statistical significant differences were observed between different impression techniques and materials. However, deviation and distortion of definitive casts had a significant difference with the master model when short impression copings and polyvinyl siloxane impression material were used (P < 0.05). In open tray technique, there was a significant difference in the rotation of analogs compared with the master model with both impression materials (P < 0.05). There was no difference between open and closed tray impression techniques; however, less distortion and deviation were observed in the open tray technique. In the closed tray impression technique, ball top screw was more accurate than short impression copings.

Effect of different impression materials and techniques on the dimensional accuracy of implant definitive casts

PubMed Central

Ebadian, Behnaz; Rismanchian, Mansor; Dastgheib, Badrosadat; Bajoghli, Farshad

2015-01-01

Background: Different factors such as impression techniques and materials can affect the passive fit between the superstructure and implant. The aim of this study was to determine the effect of different impression materials and techniques on the dimensional accuracy of implant definitive casts. Materials and Methods: Four internal hex implants (Biohorizons Ø4 mm) were placed on a metal maxillary model perpendicular to the horizontal plane in maxillary lateral incisors, right canine and left first premolar areas. Three impression techniques including open tray, closed tray using ball top screw abutments and closed tray using short impression copings and two impression materials (polyether and polyvinyl siloxane) were evaluated (n = 60). The changes in distances between implant analogues in mediolateral (x) and anteroposterior (y) directions and analogue angles in x/z and y/z directions in the horizontal plane on the definitive casts were measured by coordinate measuring machine. The data were analyzed by multivariate two-way analysis of variance and one sample t-test (α = 0.05). Results: No statistical significant differences were observed between different impression techniques and materials. However, deviation and distortion of definitive casts had a significant difference with the master model when short impression copings and polyvinyl siloxane impression material were used (P < 0.05). In open tray technique, there was a significant difference in the rotation of analogs compared with the master model with both impression materials (P < 0.05). Conclusion: There was no difference between open and closed tray impression techniques; however, less distortion and deviation were observed in the open tray technique. In the closed tray impression technique, ball top screw was more accurate than short impression copings. PMID:25878678

Comparison of the fit of cast gold crowns fabricated from the digital and the conventional impression techniques

PubMed Central

Jeon, Young-Chan; Jeong, Chang-Mo

2017-01-01

PURPOSE The purpose of this study was to compare the fit of cast gold crowns fabricated from the conventional and the digital impression technique. MATERIALS AND METHODS Artificial tooth in a master model and abutment teeth in ten patients were restored with cast gold crowns fabricated from the digital and the conventional impression technique. The forty silicone replicas were cut in three sections; each section was evaluated in nine points. The measurement was carried out by using a measuring microscope and I-Soultion. Data from the silicone replica were analyzed and all tests were performed with α-level of 0.05. RESULTS 1. The average gaps of cast gold crowns fabricated from the digital impression technique were larger than those of the conventional impression technique significantly. 2. In marginal and internal axial gap of cast gold crowns, no statistical differences were found between the two impression techniques. 3. The internal occlusal gaps of cast gold crowns fabricated from the digital impression technique were larger than those of the conventional impression technique significantly. CONCLUSION Both prostheses presented clinically acceptable results with comparing the fit. The prostheses fabricated from the digital impression technique showed more gaps, in respect of occlusal surface. PMID:28243386

Advanced Techniques in Pulmonary Function Test Analysis Interpretation and Diagnosis

PubMed Central

Gildea, T.J.; Bell, C. William

1980-01-01

The Pulmonary Functions Analysis and Diagnostic System is an advanced clinical processing system developed for use at the Pulmonary Division, Department of Medicine at the University of Nebraska Medical Center. The system generates comparative results and diagnostic impressions for a variety of routine and specialized pulmonary functions test data. Routine evaluation deals with static lung volumes, breathing mechanics, diffusing capacity, and blood gases while specialized tests include lung compliance studies, small airways dysfunction studies and dead space to tidal volume ratios. Output includes tabular results of normal vs. observed values, clinical impressions and commentary and, where indicated, a diagnostic impression. A number of pulmonary physiological and state variables are entered or sampled (A to D) with periodic status reports generated for the test supervisor. Among the various physiological variables sampled are respiratory frequency, minute ventilation, oxygen consumption, carbon dioxide production, and arterial oxygen saturation.

Achieving desired images while avoiding undesired images: exploring the role of self-monitoring in impression management.

PubMed

Turnley, W H; Bolino, M C

2001-04-01

A study was conducted to test the hypothesis that high self-monitors more effectively manage impressions than low self-monitors do. Students in work groups indicated the extent to which they used 5 impression-management tactics over the course of a semester-long project. At the project's conclusion, students provided their perceptions of the other members of their group. The relationship between impression management and image favorability was then examined across 339 student-student dyads. The results generally suggest that high self-monitors can use impression-management tactics more effectively than can low self-monitors. In particular, high self-monitors appear to be more adept than low self-monitors at using ingratiation, self-promotion, and exemplification to achieve favorable images among their colleagues.

Development and Psychometric Evaluation of a Clinical Global Impression for Schizoaffective Disorder Scale

PubMed Central

Daniel, David G; Revicki, Dennis A; Canuso, Carla M; Turkoz, Ibrahim; Fu, Dong-Jing; Alphs, Larry; Ishak, K. Jack; Bartko, John J; Lindenmayer, Jean-Pierre

2012-01-01

Objective: The Clinical Global Impression for Schizoaffective Disorder scale is a new rating scale adapted from the Clinical Global Impression scale for use in patients with schizoaffective disorder. The psychometric characteristics of the Clinical Global Impression for Schizoaffective Disorder are described. Design: Content validity was assessed using an investigator questionnaire. Inter-rater reliability was determined with 12 sets of videotaped interviews rated independently by two trained individuals. Test-retest reliability was assessed using 30 randomly selected raters from clinical trials who evaluated the same videos on separate occasions two weeks apart. Convergent and divergent validity and effect size were evaluated by comparing scores between the Clinical Global Impression for Schizoaffective Disorder and the Positive and Negative Syndrome Scale, 21-item Hamilton Rating Scale for Depression, and Young Mania Rating Scale scales using pooled patient data from two clinical trials. Clinical Global Impression for Schizoaffective Disorder scores were then linked to corresponding Positive and Negative Syndrome Scale scores. Results: Content validity was strong. Inter-rater agreement was good to excellent for most scales and subscales (intra-class correlation coefficient ≥0.50). Test-retest showed good reproducibility, with intraclass correlation coefficients ranging from 0.444 to 0.898. Spearman correlations between Clinical Global Impression for Schizoaffective Disorder domains and corresponding symptom scales were 0.60 or greater, and effect sizes for Clinical Global Impression for Schizoaffective Disorder overall and domain scores were similar to Positive and Negative Syndrome Scale Young Mania Rating Scale, and 21-item Hamilton Rating Scale for Depression scores. Raters anticipated that the scale might be less effective in distinguishing negative from depressive symptoms, and, in fact, the results here may reflect that clinical reality. Conclusion: Multiple lines of evidence support the reliability and validity of the Clinical Global Impression for Schizoaffective Disorder for studies in schizoaffective disorder. PMID:22347687

Regional and supraregional biochemistry services in Scotland: a survey of hospital laboratory users.

PubMed Central

Murphy, M J; Dryburgh, F J; Shepherd, J

1994-01-01

AIM--To ascertain the views of Scottish hospital laboratory users on aspects of regional and supraregional biochemical services offered by the Institute of Biochemistry at Glasgow Royal Infirmary. METHODS--A questionnaire was circulated asking questions or inviting opinions under various headings, including current patterns of usage of the services provided, availability of information on specimen collection requirements and reference ranges, current arrangements for transport of specimens, turnaround times for delivery of reports, layout and content of request and report forms, quantity and quality of interpretive advice, potential changes in laboratory services, and overall impression of the services provided. Opportunities were provided for free text comment. The questionnaire was circulated in 1992 to heads of department in 23 Scottish hospital biochemistry laboratories. RESULTS--Twenty one replies were received. Services used widely included trace metals/vitamins (n = 20) and specialised endocrine tests (n = 19). Other services also used included specialised lipid tests (n = 13), toxicology (n = 12), thyroid function tests (n = nine), and tumour markers (n = eight). Fifteen laboratories used one or more of the services at least weekly. Most (n = 20) welcomed the idea of a handbook providing information on specimen collection and reference ranges. Nine identified loss of specimens as a problem. Other perceived problems included the absence of reference ranges from report forms, quantity and quality of interpretive advice, and turnaround times of some tests. Overall impressions of the service(s) offered were very good (n = 12); adequate (n = seven); poor (n = one). CONCLUSIONS--Useful information was obtained about patterns of use and transport arrangements. Areas identified as requiring follow up included provision of information, alternative ways of communicating reports, and improvement in quantity and quality of interpretive advice. PMID:8027390

Margin adaptation of indirect composite inlays fabricated on flexible dies.

PubMed

Price, R B; Gerrow, J D

2000-03-01

Indirect composite restorations can be made in 1 appointment using a flexible die. Interactions between different impression materials and flexible die materials may affect the accuracy of fit and margin adaptation of the restoration. This study compared the margin adaptation of composite inlays made using the following 5 impression/flexible die material combinations; condensation silicone/polyvinyl siloxane (CS/PVS), wash viscosity polyvinyl siloxane/medium or heavy viscosity polyvinyl siloxane (PVS/PVS), irreversible hydrocolloid impression/medium viscosity polyvinyl siloxane (IH/PVS), wash viscosity polyvinyl siloxane impression/polyether (PVS/PE), with composite inlays made using a control system of a wash viscosity polyvinyl siloxane impression and a type IV stone die. For each test and control system, 10 impressions were made of a class II composite inlay preparation in a metal master die. One die was made from each impression and one composite inlay was made and finished on each die (a total of 60 inlays). Inlays were placed on the master die and the margin opening at the buccal, distal, and gingival sites was recorded with a measuring microscope (x40 magnification). The overall mean +/- SD margin openings of inlays made from the systems were as follows: PVS wash/PVS heavy viscosity 149.5 +/- 107. 4 microm; PVS wash/PVS medium viscosity 87.4 +/- 63.0 microm; IH/PVS medium viscosity 76.7 +/- 48.9 microm; CS/PVS 73.3 +/- 48.7 microm, PVS wash viscosity/PE 64.0 +/- 44.3 microm, PVS wash viscosity/stone 53.9 +/- 48.3 microm. Composite inlays made using the PVS wash viscosity/PVS heavy viscosity system had significantly larger distal, gingival, and overall mean margin openings than all other inlays (ANOVA and Fisher PLSD test; P =.05). The separating medium required between some impression and die materials did not work consistently. Composite inlays fabricated on dies made of material different than the impression material had mean buccal, distal, gingival, and overall margin openings < or =100 microm. Composite inlays made on the CS/PVS, IH/PVS medium viscosity, PVS wash viscosity/PE flexible dies, and control PVS wash viscosity/stone dies had statistically similar (P =.05) mean buccal, distal, gingival, and overall mean margin openings that were < or =100 microm. Composite inlays made on dies that were made of the same type of material as the impression material (PVS/PVS) had mean gingival margin openings >100 microm that were significantly larger than all other systems tested (P =.05).

Compendium of Dental Residents’ Research Project and Literature Reviews - 1991.

DTIC Science & Technology

1992-04-01

4-log1 0 (99.99%) reduction of any of the microorgan- isms under the test conditions. Sporicidin and 0.525% sodium hypochlorite were able to effect a...4-log1 0 reduction against S. aureus only. Impresept and 5.25% sodium hypochlorite did achieve a 4-log10 reduction in bacterial counts in all cases...alginate impressions is currently unknown and warrants investigation. Full strength (5.25%) sodium hypochlorite was effective in the shortest contact time (1

Efficacy of Several Therapeutic Agents in a Murine Model of Dry Eye Syndrome

PubMed Central

Kilic, Servet; Kulualp, Kadri

2016-01-01

In the current study, we used 56 female BALB/c mice with induced dry eye syndrome to evaluate the therapeutic effects of formal saline (FS), sodium hyaluronate (SH), diclofenac sodium (DS), olopatadine (OP), retinoic acid (RA), fluoromethanole (FML), cyclosporine A (CsA), and doxycycline hyclate (DH). All subjects were kept in an evaporative ‘dry eye cabinet’ for the assessment of blink rate, tear production, tear break-up time, and impression cytology prior to (baseline) and during weeks 2, 4, and 6 of the study. The right eyes of all subjects were treated topically with 5 µL of the test agent twice daily during weeks 2 through 6. Impression cytology and tear break-up time differed between time points in all groups and differed between groups at weeks 4 and 6. Blink rate differed by time point only in the FS, FML, and DH groups. Tear production according to the phenol red cotton thread test differed by time point for all groups except RA, CsA, and DH and differed between groups only at week 6. Among the compounds tested in the present study, DS and CsA were the most effective therapeutic agents in our mouse model of dry eye syndrome; these agents likely exert their therapeutic effect through their antiinflammatory activity. PMID:27053565

Comparative evaluation of pressure generated on a simulated maxillary oral analog by impression materials in custom trays of different spacer designs: An in vitro study.

PubMed

Chopra, Sakshi; Gupta, Narendra Kumar; Tandan, Amrit; Dwivedi, Ravi; Gupta, Swati; Agarwal, Garima

2016-01-01

Literature reveals that masticatory load on denture bearing tissues through complete dentures should be maximum on primary stress bearing areas and least on relief area in accordance with the histology of underlying tissues. A study to validate the existing beliefs was planned to compare the pressure on mucosa using selective pressure technique and minimal pressure technique, with the incorporation of two different impression materials utilizing the pressure sensors during secondary impression procedure. The study was performed using a maxillary analog. Three pressure sensors were imbedded in the oral analog, one in the mid palatine area and the other two in the right and left ridge crest. Custom trays of two different configurations were fabricated. The two impression materials tested were light body and zinc oxide eugenol. A total of 40 impressions were made. A constant weight of 1 kg was placed, and the pressure was recorded as initial and end pressures. A significant difference in the pressure produced using different impression materials was found (P < 0.001). Light body vinyl polysiloxane produced significantly lesser pressure than zinc oxide eugenol impression materials. The presence of relief did affect the magnitude of pressure at various locations. All impression materials produced pressure during maxillary edentulous impression making. Tray modification is an important factor in changing the amount of pressure produced. The impression materials used also had a significant role to play on the pressures acting on the tissues during impression procedure. Light body VPS impression material may be recommended to achieve minimal pressure on the denture bearing tissues in both selective as well as minimal pressure techniques.

Clinical Evaluation of Different Pre-impression Preparation Procedures of Dental Arch

PubMed Central

Arora, Nitin; Arora, Monika; Gupta, Naveen; Agarwal, Manisha; Verma, Rohit; Rathod, Pankaj

2015-01-01

Background: Bubbles and voids on the occlusal surface impede the actual intercuspation and pre-impression preparation aims to reduce the incidence of air bubbles and voids as well as influences the quality of occlusal reproduction and actual clinical intercuspation in the articulator. The study was undertaken to determine the influence of different pre-impression preparation procedures of antagonistic dental arch on the quality of the occlusal reproduction of the teeth in irreversible hydrocolloid impressions and to determine most reliable pre-impression preparation method to reduce the incidence of air bubbles. Materials and Methods: A total of 20 subjects were selected having full complement of mandibular teeth from second molar to second molar with well demarcated cusp height. 200 impressions were made with irreversible hydrocolloid material. The impressions were divided into five groups of 40 impressions each and each group had one specific type of pre-impression preparation. All the impressions were poured in die stone. A stereomicroscope with graduated eyepiece was used to count the number of bubbles on the occlusal surface of premolars and molars. The mean and standard deviations were calculated for each group. Mann–Whitney U-test was applied to find the significant difference between different groups. Results: Least bubbles were found in the group in which oral cavity was dried by saliva ejector and fluid hydrocolloid was finger painted onto the occlusal surfaces immediately before the placement of impression tray in the mouth. Conclusion: It was found that finger painting the tooth surfaces with fluid hydrocolloid immediately before the placement of loaded impression tray in the mouth was the most reliable method. The oral cavity can be cleared more easily of excess saliva by vacuum suction rather than by use of an astringent solution. PMID:26229376

Clinical Evaluation of Different Pre-impression Preparation Procedures of Dental Arch.

PubMed

Arora, Nitin; Arora, Monika; Gupta, Naveen; Agarwal, Manisha; Verma, Rohit; Rathod, Pankaj

2015-07-01

Bubbles and voids on the occlusal surface impede the actual intercuspation and pre-impression preparation aims to reduce the incidence of air bubbles and voids as well as influences the quality of occlusal reproduction and actual clinical intercuspation in the articulator. The study was undertaken to determine the influence of different pre-impression preparation procedures of antagonistic dental arch on the quality of the occlusal reproduction of the teeth in irreversible hydrocolloid impressions and to determine most reliable pre-impression preparation method to reduce the incidence of air bubbles. A total of 20 subjects were selected having full complement of mandibular teeth from second molar to second molar with well demarcated cusp height. 200 impressions were made with irreversible hydrocolloid material. The impressions were divided into five groups of 40 impressions each and each group had one specific type of pre-impression preparation. All the impressions were poured in die stone. A stereomicroscope with graduated eyepiece was used to count the number of bubbles on the occlusal surface of premolars and molars. The mean and standard deviations were calculated for each group. Mann-Whitney U-test was applied to find the significant difference between different groups. Least bubbles were found in the group in which oral cavity was dried by saliva ejector and fluid hydrocolloid was finger painted onto the occlusal surfaces immediately before the placement of impression tray in the mouth. It was found that finger painting the tooth surfaces with fluid hydrocolloid immediately before the placement of loaded impression tray in the mouth was the most reliable method. The oral cavity can be cleared more easily of excess saliva by vacuum suction rather than by use of an astringent solution.

Direct 3-D morphological measurements of silicone rubber impression using micro-focus X-ray CT.

PubMed

Kamegawa, Masayuki; Nakamura, Masayuki; Fukui, Yu; Tsutsumi, Sadami; Hojo, Masaki

2010-01-01

Three-dimensional computer models of dental arches play a significant role in prosthetic dentistry. The microfocus X-ray CT scanner has the advantage of capturing precise 3D shapes of deep fossa, and we propose a new method of measuring the three-dimensional morphology of a dental impression directly, which will eliminate the conversion process to dental casts. Measurement precision and accuracy were evaluated using a standard gage comprised of steel balls which simulate the dental arch. Measurement accuracy, standard deviation of distance distribution of superimposed models, was determined as +/-0.050 mm in comparison with a CAD model. Impressions and casts of an actual dental arch were scanned by microfocus X-ray CT and three-dimensional models were compared. The impression model had finer morphology, especially around the cervical margins of teeth. Within the limitations of the current study, direct three-dimensional impression modeling was successfully demonstrated using microfocus X-ray CT.

Accuracy and Precision of Silicon Based Impression Media for Quantitative Areal Texture Analysis

PubMed Central

Goodall, Robert H.; Darras, Laurent P.; Purnell, Mark A.

2015-01-01

Areal surface texture analysis is becoming widespread across a diverse range of applications, from engineering to ecology. In many studies silicon based impression media are used to replicate surfaces, and the fidelity of replication defines the quality of data collected. However, while different investigators have used different impression media, the fidelity of surface replication has not been subjected to quantitative analysis based on areal texture data. Here we present the results of an analysis of the accuracy and precision with which different silicon based impression media of varying composition and viscosity replicate rough and smooth surfaces. Both accuracy and precision vary greatly between different media. High viscosity media tested show very low accuracy and precision, and most other compounds showed either the same pattern, or low accuracy and high precision, or low precision and high accuracy. Of the media tested, mid viscosity President Jet Regular Body and low viscosity President Jet Light Body (Coltène Whaledent) are the only compounds to show high levels of accuracy and precision on both surface types. Our results show that data acquired from different impression media are not comparable, supporting calls for greater standardisation of methods in areal texture analysis. PMID:25991505

Neural correlates of self-deception and impression-management.

PubMed

Farrow, Tom F D; Burgess, Jenny; Wilkinson, Iain D; Hunter, Michael D

2015-01-01

Self-deception and impression-management comprise two types of deceptive, but generally socially acceptable behaviours, which are common in everyday life as well as being present in a number of psychiatric disorders. We sought to establish and dissociate the 'normal' brain substrates of self-deception and impression-management. Twenty healthy participants underwent fMRI scanning at 3T whilst completing the 'Balanced Inventory of Desirable Responding' test under two conditions: 'fake good', giving the most desirable impression possible and 'fake bad' giving an undesirable impression. Impression-management scores were more malleable to manipulation via 'faking' than self-deception scores. Response times to self-deception questions and 'fake bad' instructions were significantly longer than to impression-management questions and 'fake good' instructions respectively. Self-deception and impression-management manipulation and 'faking bad' were associated with activation of medial prefrontal cortex (mPFC) and left ventrolateral prefrontal cortex (vlPFC). Impression-management manipulation was additionally associated with activation of left dorsolateral prefrontal cortex and left posterior middle temporal gyrus. 'Faking bad' was additionally associated with activation of right vlPFC, left temporo-parietal junction and right cerebellum. There were no supra-threshold activations associated with 'faking good'. Our neuroimaging data suggest that manipulating self-deception and impression-management and more specifically 'faking bad' engages a common network comprising mPFC and left vlPFC. Shorter response times and lack of dissociable neural activations suggests that 'faking good', particularly when it comes to impression-management, may be our most practiced 'default' mode. Copyright © 2014 Elsevier Ltd. All rights reserved.

In vivo evaluation of inter-operator reproducibility of digital dental and conventional impression techniques

PubMed Central

Kamimura, Emi; Tanaka, Shinpei; Takaba, Masayuki; Tachi, Keita; Baba, Kazuyoshi

2017-01-01

Purpose The aim of this study was to evaluate and compare the inter-operator reproducibility of three-dimensional (3D) images of teeth captured by a digital impression technique to a conventional impression technique in vivo. Materials and methods Twelve participants with complete natural dentition were included in this study. A digital impression of the mandibular molars of these participants was made by two operators with different levels of clinical experience, 3 or 16 years, using an intra-oral scanner (Lava COS, 3M ESPE). A silicone impression also was made by the same operators using the double mix impression technique (Imprint3, 3M ESPE). Stereolithography (STL) data were directly exported from the Lava COS system, while STL data of a plaster model made from silicone impression were captured by a three-dimensional (3D) laboratory scanner (D810, 3shape). The STL datasets recorded by two different operators were compared using 3D evaluation software and superimposed using the best-fit-algorithm method (least-squares method, PolyWorks, InnovMetric Software) for each impression technique. Inter-operator reproducibility as evaluated by average discrepancies of corresponding 3D data was compared between the two techniques (Wilcoxon signed-rank test). Results The visual inspection of superimposed datasets revealed that discrepancies between repeated digital impression were smaller than observed with silicone impression. Confirmation was forthcoming from statistical analysis revealing significantly smaller average inter-operator reproducibility using a digital impression technique (0.014± 0.02 mm) than when using a conventional impression technique (0.023 ± 0.01 mm). Conclusion The results of this in vivo study suggest that inter-operator reproducibility with a digital impression technique may be better than that of a conventional impression technique and is independent of the clinical experience of the operator. PMID:28636642

Forming First Impressions of Others in Schizophrenia: Impairments In Fast Processing and In Use of Spatial Frequency Information

PubMed Central

Vakhrusheva, J; Zemon, V; Bar, M; Weiskopf, NG; Tremeau, F; Petkova, E; Su, Z; Abeles, I; Butler, PD

2014-01-01

Individuals form first impressions of others all the time, which affects their social functioning. Typical adults form threat impressions in faces with neutral expressions quickly, requiring less than 40 ms. These impressions appear to be mediated by low spatial frequency (LSF) content in the images. Little is known, however, about mechanisms of first impression formation in schizophrenia. The current study investigated how quickly individuals with schizophrenia can form consistent impressions of threat compared with controls and explored the mechanisms involved. Patients and controls were presented intact, LSF- or high spatial frequency (HSF)-filtered faces with durations that varied from 39 – 1703 ms and were asked to rate how threatening each face was on a scale from 1 to 5. In order to assess the speed of impression formation for intact faces, correlations were calculated for ratings made at each duration compared to a reference duration of 1703 ms for each group. Controls demonstrated a significant relation for intact faces presented for 39 ms, whereas patients required 390 ms to demonstrate a significant relation with the reference duration. For controls, LSFs primarily contributed to the formation of consistent threat impressions at 39 ms, whereas patients showed a trend for utilizing both LSF and HSF information to form consistent threat impressions at 390 ms. Results indicate that individuals with schizophrenia require a greater integration time to form a stable “first impression” of threat, which may be related to the need to utilize compensatory mechanisms such as HSF, as well as LSF, information. PMID:25458862

Casting ability of selected impression materials tested in different conditions in an in vitro sulcus model.

PubMed

Kolbeck, Carola; Rosentritt, Martin; Lang, Reinhold; Schiller, Manuela; Handel, Gerhard

2009-10-01

To test casting capacities of impression materials under dry and wet sulcular conditions in vitro. An incisor with a circular shoulder preparation (1 mm) was inserted in a primary mold. A shiftable secondary mold allowed adaptation of sulcular depth (1 to 4 mm). An outer circular chamfer assured reproducible positioning of an impression material carrier. Tested materials were PVS of differing viscosities (extra low, Panasil Contact Plus [ELV]; low, Affinis Light Body [LV]; and medium, Virtual Monophase [MV]) and one polyether material of low viscosity (Permadyne Garant [PE]). Impressions were made with sulcular depths of 1 to 4 mm in wet and 1 and 4 mm in dry conditions, cut in half, and digitized with a light microscope (Stemi SV8). Surface area of the region of interest (ROI, at inner angle of preparation) was determined with Optimas 6.2. Medians were calculated, and statistical analysis was performed using the Mann-Whitney U test (P # .05). Median values of the measurements under wet condition demonstrated the smallest ROI areas for the ELV (297-330[pixel]) and the MV (253-421[pixel]) materials followed by the LV (582-745[pixel]) and the PELV (544-823[pixel]). All materials showed significantly higher values for the wet compared to dry sulcular conditions. Repeated measurements showed no significant differences to the corresponding first determined series. The sulcus model is applicable to assess casting abilities of impression materials in clinically approximated sulcular conditions. The PVS materials with extra low and medium viscosities showed the best properties in dry and wet conditions.

[Influence of autoclave sterilization on dimensional stability and detail reproduction of 5 additional silicone impression materials].

PubMed

Xu, Tong-kai; Sun, Zhi-hui; Jiang, Yong

2012-03-01

To evaluate the dimensional stability and detail reproduction of five additional silicone impression materials after autoclave sterilization. Impressions were made on the ISO 4823 standard mold containing several marking lines, in five kinds of additional silicone. All the impressions were sterilized by high temperature and pressure (135 °C, 212.8 kPa) for 25 min. Linear measurements of pre-sterilization and post-sterilization were made with a measuring microscope. Statistical analysis utilized single-factor analysis with pair-wise comparison of mean values when appropriate. Hypothesis testing was conducted at alpha = 0.05. No significant difference was found between the pre-sterilization and post-sterilization conditions for all locations, and all the absolute valuse of linear rate of change less than 8%. All the sterilization by the autoclave did not affect the surfuce detail reproduction of the 5 impression materials. The dimensional stability and detail reproduction of the five additional silicone impression materials in the study was unaffected by autoclave sterilization.

[Study of the appearance difference of lower complete denture between functional and anatomic impression techniques].

PubMed

Zhong, Qun; Wu, Xue-yin; Shen, Qing-yi; Shen, Qing-ping

2012-04-01

To compare the difference in oblique external ridge, oblique internal ridge and alveolar process crest of lower complete denture base made through functional impression and anatomic impression techniques. Fifteen patients were chosen to treat with two kinds of complete dentures through functional impression and anatomic impression technique respectively. 3D laser scanner was used to scan the three-dimensional model of the denture base and the differences of the surface structural between two techniques in alveolar process crest, external and internal oblique ridges were analyzed, using paired t test with SPSS 12.0 software package. Between the two techniques, there were significant differences in the areas of internal and external oblique ridge(P<0.01); there was no significant difference in the main support areas(P>0.05). The results explain why there is less tenderness when functional impression technique is applied. The differences measured also indicate that sufficient buffering should be made in external and internal oblique ridge areas in clinic.

Look at me, I'm happy and creative: The effect of impression management on behavior in social presence.

PubMed

Uziel, Liad

2010-12-01

The present research tested competing approaches to individual differences in impression management (as measured with social desirability scales) and their implication for behavior in social contexts. A defensiveness approach argues that impression management is a source of defensive self-presentation, which causes performance impairment in public social settings. The competing adjustment approach argues that impression management measures friendliness and self-control, which should bring about performance facilitation in public social settings. To decide between these approaches, two experiments utilized a social facilitation paradigm, whereby task performance was compared between an alone and a public condition. The results supported the predictions of the adjustment approach. Across different tasks, a high impression management score was associated with performance facilitation in social presence, expressed in greater creativity, positive implicit affect, and high self-control. The results reveal previously unnoticed constructive effects of impression management, supporting the reframing of the trait as reflecting interpersonally oriented self-control.

Marginal adaptation of CAD-CAM onlays: Influence of preparation design and impression technique.

PubMed

Lima, Fernanda Ferruzzi; Neto, Constantino Fernandes; Rubo, José H; Santos, Gildo Coelho; Moraes Coelho Santos, Maria Jacinta

2018-03-15

Factors that may affect the marginal adaptation of computer-aided design and computer-aided manufacturing (CAD-CAM) restorations include preparation design, impression technique, and CAD-CAM system. The influence of impression technique and preparation design on CAD-CAM partial coverage restorations has not been fully addressed. The purpose of this in vitro study was to investigate the influence of direct and indirect digital impression techniques and 2 preparation designs on the marginal adaptation of CAD-CAM onlays. Two mesio-occlusal buccal onlay preparations with reduction of the mesiobuccal cusp were made: conventional preparation (CP) with a 1.2-mm modified shoulder margin and modified preparation (MP) flat cuspal reduction without shoulder. Virtual models were generated from each preparation by using a digital scanner (BlueCam; Dentsply Sirona) from the plastic teeth (direct digital impression) or from the stone dies (indirect digital impression). Onlays were designed using a CAD-CAM system (CEREC 4.0; Dentsply Sirona), and nanoceramic resin blocks (Lava Ultimate Restorative; 3M ESPE) were milled using the CEREC MCX milling machine. Marginal discrepancy was evaluated using an optical stereomicroscope at ×25 magnification in 18 locations distributed along the margins of the preparation. The data were analyzed by using 3-way ANOVA followed by the Tukey HSD test (α=.05). CP presented a statistically significant reduced average marginal adaptation (59 ±50 μm) than did MP (69 ±58 μm) (P<.001). The Tukey HSD test showed the presence of a significantly larger marginal discrepancy in the mesial and buccal locations of MP when compared with CP. Regarding impression techniques, the buccal location presented the smallest average marginal discrepancy in restorations fabricated with indirect impression when compared with direct impression (42 ±33 μm and 60 ±39 μm) (P<.001). The results showed that conventional preparation with a modified shoulder margin presented improved marginal adaptation compared with modified preparation with flat cuspal reduction. Direct and indirect digital impression techniques produced restorations within a clinically acceptable range; however, the indirect impression technique resulted in the fabrication of restorations with superior marginal adaptation on the buccal location. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Calculating Clinically Significant Change: Applications of the Clinical Global Impressions (CGI) Scale to Evaluate Client Outcomes in Private Practice

ERIC Educational Resources Information Center

Kelly, Peter James

2010-01-01

The Clinical Global Impressions (CGI) scale is a therapist-rated measure of client outcome that has been widely used within the research literature. The current study aimed to develop reliable and clinically significant change indices for the CGI, and to demonstrate its application in private psychological practice. Following the guidelines…

Impressions and purchasing intentions of Japanese consumers regarding pork produced by 'Ecofeed,' a trademark of food-waste or food co-product animal feed certified by the Japanese government.

PubMed

Sasaki, Keisuke; Aizaki, Hideo; Motoyama, Michiyo; Ohmori, Hideyuki; Kawashima, Tomoyuki

2011-02-01

Impressions and purchasing intentions of Japanese consumers regarding pork produced by 'Ecofeed', a trademark of food-waste or co-product animal feeds certified by the Japanese government, were investigated by a questionnaire on the Internet. 'Ecofeed' did not elicit specific impressions as compared to domestic, imported, Kurobuta (in Japan), and specific pathogen-free (SPF) pork. Purchasing intent for 'Ecofeed' pork was the second lowest of the five pork products. Knowledge and purchasing experience regarding 'Ecofeed' pork was the lowest of the five pork products. Respondents were classified into four categories according to their impressions of 'Ecofeed' pork. The largest category of respondents did not have any specific impression of 'Ecofeed' pork and had little knowledge of pork farming. A category that had a positive impression for 'Ecofeed' pork had high knowledge of the pork farming system. In order to establish 'Ecofeed' pork in Japan, our results suggest that information disclosure and education about 'Ecofeed', its certification system, environmental benefits and the current self-efficiency ratio of animal feed, are needed. © 2010 The Authors. Journal compilation © 2010 Japanese Society of Animal Science.

On Being Liked on the Web and in the “Real World”: Consistency in First Impressions across Personal Webpages and Spontaneous Behavior

PubMed Central

Weisbuch, Max; Ivcevic, Zorana; Ambady, Nalini

2009-01-01

With recent growth in the use of personal webpages and online social networking, people are changing the way that they meet and form impressions of each other. The current research examines the correspondence in impressions formed from face-to-face interaction and personal webpages. As expected, people liked by interaction partners were also liked on the basis of their Facebook® pages. Across the two social mediums, social perceivers utilized analogous criteria in forming impressions: interaction partners and webpage viewers liked people who were socially expressive in face-to-face interaction and personal webpages, respectively. Finally, webpage expressivity and webpage self-disclosure were independent constructs, predictive of face-to-face counterparts: nonverbal expressivity and verbal self-disclosure. Implications for the changing landscape of social perception are discussed. PMID:20161314

Dimensional accuracy of resultant casts made by a monophase, one-step and two-step, and a novel two-step putty/light-body impression technique: an in vitro study.

PubMed

Caputi, Sergio; Varvara, Giuseppe

2008-04-01

Dimensional accuracy when making impressions is crucial to the quality of fixed prosthodontic treatment, and the impression technique is a critical factor affecting this accuracy. The purpose of this in vitro study was to compare the dimensional accuracy of a monophase, 1- and 2-step putty/light-body, and a novel 2-step injection impression technique. A stainless steel model with 2 abutment preparations was fabricated, and impressions were made 15 times with each technique. All impressions were made with an addition-reaction silicone impression material (Aquasil) and a stock perforated metal tray. The monophase impressions were made with regular body material. The 1-step putty/light-body impressions were made with simultaneous use of putty and light-body materials. The 2-step putty/light-body impressions were made with 2-mm-thick resin-prefabricated copings. The 2-step injection impressions were made with simultaneous use of putty and light-body materials. In this injection technique, after removing the preliminary impression, a hole was made through the polymerized material at each abutment edge, to coincide with holes present in the stock trays. Extra-light-body material was then added to the preliminary impression and further injected through the hole after reinsertion of the preliminary impression on the stainless steel model. The accuracy of the 4 different impression techniques was assessed by measuring 3 dimensions (intra- and interabutment) (5-mum accuracy) on stone casts poured from the impressions of the stainless steel model. The data were analyzed by 1-way ANOVA and Student-Newman-Keuls test (alpha=.05). The stone dies obtained with all the techniques had significantly larger dimensions as compared to those of the stainless steel model (P<.01). The order for highest to lowest deviation from the stainless steel model was: monophase, 1-step putty/light body, 2-step putty/light body, and 2-step injection. Significant differences among all of the groups for both absolute dimensions of the stone dies, and their percent deviations from the stainless steel model (P<.01), were noted. The 2-step putty/light-body and 2-step injection techniques were the most dimensionally accurate impression methods in terms of resultant casts.

Randomized controlled within-subject evaluation of digital and conventional workflows for the fabrication of lithium disilicate single crowns. Part I: digital versus conventional unilateral impressions.

PubMed

Benic, Goran I; Mühlemann, Sven; Fehmer, Vincent; Hämmerle, Christoph H F; Sailer, Irena

2016-11-01

Trials comparing the overall performance of fully digital and conventional workflows in reconstructive dentistry are needed. The purpose of the first part of this randomized controlled clinical trial was to determine whether optical impressions produce different results from conventional impressions with respect to time efficiency and patient and operator perceptions of the clinical workflow. Three digital impressions and 1 conventional impression were made in each of 10 participants according to a randomly generated sequence. The digital systems were Lava COS, iTero, and Cerec Bluecam. The conventional impression was made with the closed-mouth technique and polyvinyl siloxane material. The time needed for powdering, impressions, and interocclusal record was recorded. Patient and clinician perceptions of the procedures were rated by means of visual analog scales. The paired t test with Bonferroni correction was applied to detect differences (α=.05/6=.0083). The mean total working time ±standard deviation amounted to 260 ±66 seconds for the conventional impression, 493 ±193 seconds for Lava, 372 ±126 seconds for iTero, and 357 ±55 seconds for Cerec. The total working time for the conventional impression was significantly lower than that for Lava and Cerec. With regard to the working time without powdering, the differences between the methods were not statistically significant. The patient rating (very uncomfortable=0; comfortable=100) measured 61 ±34 for conventional impression, 71 ±18 for Lava, 66 ±20 for iTero, and 48 ±18 for Cerec. The differences were not statistically significant. The clinician rating (simple=0; very difficult=100) was 13 ±13 for the conventional impression, 54 ±27 for Lava, 22 ±11 for iTero, and 36 ±23 for Cerec. The differences between the conventional impression and Lava and between iTero and Lava were statistically significant. The conventional impression was more time-effective than the digital impressions. In terms of patient comfort, no differences were found between the conventional and the digital techniques. With respect to the clinician perception of difficulty, the conventional impression and the digital impression with iTero revealed more favorable outcomes than the digital impression with Lava. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Effects of implant system, impression technique, and impression material on accuracy of the working cast.

PubMed

Wegner, Kerstin; Weskott, Katharina; Zenginel, Martha; Rehmann, Peter; Wöstmann, Bernd

2013-01-01

This in vitro study aimed to identify the effects of the implant system, impression technique, and impression material on the transfer accuracy of implant impressions. The null hypothesis tested was that, in vitro and within the parameters of the experiment, the spatial relationship of a working cast to the placement of implants is not related to (1) the implant system, (2) the impression technique, or (3) the impression material. A steel maxilla was used as a reference model. Six implants of two different implant systems (Standard Plus, Straumann; Semados, Bego) were fixed in the reference model. The target variables were: three-dimensional (3D) shift in all directions, implant axis direction, and rotation. The target variables were assessed using a 3D coordinate measuring machine, and the respective deviations of the plaster models from the nominal values of the reference model were calculated. Two different impression techniques (reposition/pickup) and four impression materials (Aquasil Ultra, Flexitime, Impregum Penta, P2 Magnum 360) were investigated. In all, 80 implant impressions for each implant system were taken. Statistical analysis was performed using multivariate analysis of variance. The implant system significantly influenced the transfer accuracy for most spatial dimensions, including the overall 3D shift and implant axis direction. There was no significant difference between the two implant systems with regard to rotation. Multivariate analysis of variance showed a significant effect on transfer accuracy only for the implant system. Within the limits of the present study, it can be concluded that the transfer accuracy of the intraoral implant position on the working cast is far more dependent on the implant system than on the selection of a specific impression technique or material.

The Accuracy of Four Impression-making Techniques in Angulated Implants Based on Vertical Gap

PubMed Central

Saboury, Abolfazl; Neshandar Asli, Hamid; Dalili Kajan, Zahra

2017-01-01

Statement of the Problem: Precision of the impression taken from implant positions significantly determines accurate fit of implant-supported prostheses. An imprecise impression may produce prosthesis misfit. Purpose: This study aimed to evaluate the accuracy of four impression-making techniques for angulated implants by stereomicroscope through measuring the vertical marginal gaps between the cemented metal framework and the implant analog. Materials and Method: A definitive cast with two 15° mesially angulated implants served as the standard reference for making all the impressions and later for accuracy evaluation. Four groups of five samples were evaluated: (1) closed-tray snap-fit transfer, (2) open-tray nonsplinted impression coping, (3) metal splinted impression coping, and (4) fabricated acrylic resin transfer cap. A gold-palladium framework was fabricated over the angulated implant abutments, the fit of which was used as reference. The gaps between the metal framework and the implant analogs were measured in sample groups. Corresponding means for each technique and the definitive cast were compared by using ANOVA and post hoc tests. Results: The mean marginal gap was 38.16±0µm in definitive cast, 89±19.74µm in group 1, 78.66±20.63µm in group 2, 54.16±24.29µm in group 3, and 55.83±18.30µm in group 4. ANOVA revealed significant differences between the definitive cast and groups 1 and 2, but not with groups 3 and 4 (p< 0.05). Conclusion: Vertical gap measurements showed that metal splinted impression coping and fabricated acrylic resin transfer cap techniques produced quite more accurate impressions than closed-tray snap-fit transfer and open-tray nonsplinted impression coping techniques do. The fabricated acrylic resin transfer cap technique seems to be a reliable impression-making method. PMID:29201973

Impressions of Humanness for Android Robot may Represent an Endophenotype for Autism Spectrum Disorders.

PubMed

Kumazaki, Hirokazu; Warren, Zachary; Swanson, Amy; Yoshikawa, Yuichiro; Matsumoto, Yoshio; Ishiguro, Hiroshi; Sarkar, Nilanjan; Minabe, Yoshio; Kikuchi, Mitsuru

2018-02-01

Identification of meaningful endophenotypes may be critical to unraveling the etiology and pathophysiology of autism spectrum disorders (ASD). We investigated whether impressions of "humanness" for android robot might represent a candidate characteristic of an ASD endophenotype. We used a female type of android robot with an appearance similar to that of a real person. Significant differences in overall impressions of 'humanness' for android robot were found between adolescents with ASD and typical development (TD) controls, as well as parents of children with ASD and parents of TD controls. Our current work does suggest robotic systems could potentially play an intelligent role in dissecting ASD heterogeneity.

A Validation Study of the Impression Replica Technique.

PubMed

Segerström, Sofia; Wiking-Lima de Faria, Johanna; Braian, Michael; Ameri, Arman; Ahlgren, Camilla

2018-04-17

To validate the well-known and often-used impression replica technique for measuring fit between a preparation and a crown in vitro. The validation consisted of three steps. First, a measuring instrument was validated to elucidate its accuracy. Second, a specimen consisting of male and female counterparts was created and validated by the measuring instrument. Calculations were made for the exact values of three gaps between the male and female. Finally, impression replicas were produced of the specimen gaps and sectioned into four pieces. The replicas were then measured with the use of a light microscope. The values received from measuring the specimen were then compared with the values received from the impression replicas, and the technique was thereby validated. The impression replica technique overvalued all measured gaps. Depending on location of the three measuring sites, the difference between the specimen and the impression replicas varied from 47 to 130 μm. The impression replica technique overestimates gaps within the range of 2% to 11%. The validation of the replica technique enables the method to be used as a reference when testing other methods for evaluating fit in dentistry. © 2018 by the American College of Prosthodontists.

A metric study of insole foot impressions in footwear of identical twins.

PubMed

Nirenberg, Michael S; Krishan, Kewal; Kanchan, Tanuj

2017-11-01

Foot impressions are of utmost importance in crime scene investigations. Foot impressions are available in the form of barefoot prints, sock-clad footprints, and as impressions within footwear. Sometimes suspects leave their footwear at the crime scene, and the insole of this footwear may contain the foot impression of the suspect which may be important evidence linking him or her to the crime. The task of identification based on the analysis of footprints can be challenging when the footprints belonging to one of the identical twin is available for examination. The present study is based on the quantitative measures of the foot impressions in the footwear of adult identical twins. The study was conducted on four sets of female monozygotic twins from the United States of America. A total of 17 length and breadth measurements were taken on each foot impression. A combination of Reel Method and Extended Gunn Method was utilized to produce the measurements. The measurements of the foot impressions were compared among the twins on the right and the left side. Differences were found in the various footprint measurements among the twins. The study's sample size was not large enough to apply robust statistical tests, but the study is significant in that it presents the first detailed comparative analysis of a large number of measurements of insole foot impressions of adult twins. The observations derived from the study are likely to assist forensic investigations in cases involving the foot impressions of the twins. Copyright © 2017 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Motion cues that make an impression: Predicting perceived personality by minimal motion information.

PubMed

Koppensteiner, Markus

2013-11-01

The current study presents a methodology to analyze first impressions on the basis of minimal motion information. In order to test the applicability of the approach brief silent video clips of 40 speakers were presented to independent observers (i.e., did not know speakers) who rated them on measures of the Big Five personality traits. The body movements of the speakers were then captured by placing landmarks on the speakers' forehead, one shoulder and the hands. Analysis revealed that observers ascribe extraversion to variations in the speakers' overall activity, emotional stability to the movements' relative velocity, and variation in motion direction to openness. Although ratings of openness and conscientiousness were related to biographical data of the speakers (i.e., measures of career progress), measures of body motion failed to provide similar results. In conclusion, analysis of motion behavior might be done on the basis of a small set of landmarks that seem to capture important parts of relevant nonverbal information.

Modification of pH Conferring Virucidal Activity on Dental Alginates

PubMed Central

Nallamuthu, Navina; Braden, Michael; Oxford, John; Williams, David; Patel, Mangala

2015-01-01

To formulate an alginate dental impression material with virucidal properties, experimental alginate dental impression materials were developed and the formulations adjusted in order to study the effect on pH profiles during setting. Commercially available materials served as a comparison. Eight experimental materials were tested for antiviral activity against Herpes Simplex Virus type 1 (HSV-1). Changing the amount of magnesium oxide (MgO) used in the experimental formulations had a marked effect on pH. Increasing MgO concentration corresponded with increased pH values. All experimental materials brought about viral log reductions ranging between 0.5 and 4.0 over a period of 4 h. The material with the lowest pH was the most effective. The current work highlights the very important role of MgO in controlling pH profiles. This knowledge has been applied to the formulation of experimental alginates; where materials with pH values of approximately 4.2–4.4 are able to achieve a significant log reduction when assayed against HSV-1. PMID:28788042

Evaluation of Different Disinfactants on Dimensional Accuracy and Surface Quality of Type IV Gypsum Casts Retrieved from Elastomeric Impression Materials.

PubMed

Pal, P K; Kamble, Suresh S; Chaurasia, Ranjitkumar Rampratap; Chaurasia, Vishwajit Rampratap; Tiwari, Samarth; Bansal, Deepak

2014-06-01

The present study was done to evaluate the dimensional stability and surface quality of Type IV gypsum casts retrieved from disinfected elastomeric impression materials. In an in vitro study contaminated impression material with known bacterial species was disinfected with disinfectants followed by culturing the swab sample to assess reduction in level of bacterial colony. Changes in surface detail reproduction of impression were assessed fallowing disinfection. All the three disinfectants used in the study produced a 100% reduction in colony forming units of the test organisms. All the three disinfectants produced complete disinfection, and didn't cause any deterioration in surface detail reproduction. How to cite the article: Pal PK, Kamble SS, Chaurasia RR, Chaurasia VR, Tiwari S, Bansal D. Evaluation of dimensional stability and surface quality of type IV gypsum casts retrieved from disinfected elastomeric impression materials. J Int Oral Health 2014;6(3):77-81.

Impression formation of tests: retrospective judgments of performance are higher when easier questions come first.

PubMed

Jackson, Abigail; Greene, Robert L

2014-11-01

Four experiments are reported on the importance of retrospective judgments of performance (postdictions) on tests. Participants answered general knowledge questions and estimated how many questions they answered correctly. They gave higher postdictions when easy questions preceded difficult questions. This was true when time to answer each question was equalized and constrained, when participants were instructed not to write answers, and when questions were presented in a multiple-choice format. Results are consistent with the notion that first impressions predominate in overall perception of test difficulty.

A Test of an Impression Management Interpretation of Public Responses to Positive Inequity.

ERIC Educational Resources Information Center

Rivera, Alba N.; Tedeschi, James T.

Recent evidence indicates that subjects experience "distress" when they are beneficiaries of an inequitable distribution of rewards in a dyad. Yet, reinforcement theory postulates that individuals should experience more pleasure, the greater the reward they receive. An impression management hypothesis would reconcile these apparently opposing…

The effect of impression volume and double-arch trays on the registration of maximum intercuspation.

PubMed

Hahn, Sara M; Millstein, Philip L; Kinnunen, Taru H; Wright, Robert F

2009-12-01

The type of double-arch trays used may affect occlusion. The purpose of this study was to determine what effect, if any, double-arch tray design and impression material volume had on the registration of maximum intercuspation (MI). Quadrant impressions were made on articulated fracture-resistant dental casts mounted in maximum intercuspation occlusion. Three types of sideless double-arch impression trays were used: First Bite with nylon webbing, Sultan's 3-Way with double crosshatch webbing, and Premium's 3-in-1 Tray with single crosshatch webbing. Vinyl polysiloxane impression material (Aquasil Ultra Rigid Fast Set) was distributed at 2 different volumes (5.4 ml and 8.3 ml), and 60 impressions were made (n=10). A weight of 1.2 kg was placed on the upper arm of an Artex articulator, ensuring complete closure. The impressions were allowed to polymerize for 5 minutes. After polymerization, specimens were placed on a light box, and a camera set at a fixed distance was used to capture the light transmission that was projected through the impression material. The camera transferred the information to an image analysis program (ImageJ). This system allowed the different amounts of light projected through the impression to be translated into a gray scale value (GSV), which was assigned a thickness value, in millimeters, of a specified occlusal contact area. To assess reliability of the experimental design, 10 control impressions were made by directly applying impression material onto the typodont. These were analyzed in the same manner as the impressions made with trays. A 2-way ANOVA comparing volume by tray type was used (alpha=.05). This was followed by a Tukey HSD test. There was no main effect for volume of impression material (P=.71). Tray type was significantly different (P<.001). Impressions made with Sultan trays were significantly less accurate than impressions made with First Bite or Premium impression trays. The Premium tray type had the highest mean (SD) GSV, 179.8 (8.1), significantly higher than First Bite (164.7 (19.8); P<.001) or Sultan (82.8 (7.4); P<.001) trays. This in vitro study demonstrated that certain trays hinder closure into MI, which may negatively affect the accuracy of record making.

Objective analysis of impressed chisel toolmarks

DOE PAGES

Spotts, Ryan; Chumbley, L. Scott

2015-08-06

Historical and recent challenges to the practice of comparative forensic examination have created a driving force for the formation of objective methods for toolmark identification. In this study, fifty sequentially manufactured chisels were used to create impression toolmarks in lead (500 toolmarks total). An algorithm previously used to statistically separate known matching and nonmatching striated screwdriver marks and quasi-striated plier marks was used to evaluate the chisel marks. Impression toolmarks, a more complex form of toolmark, pose a more difficult test for the algorithm that was originally designed for striated toolmarks. Lastly, results show in this instance that the algorithmmore » can separate matching and nonmatching impression marks, providing further validation of the assumption that toolmarks are identifiably unique.« less

Accuracy of complete-arch dental impressions: a new method of measuring trueness and precision.

PubMed

Ender, Andreas; Mehl, Albert

2013-02-01

A new approach to both 3-dimensional (3D) trueness and precision is necessary to assess the accuracy of intraoral digital impressions and compare them to conventionally acquired impressions. The purpose of this in vitro study was to evaluate whether a new reference scanner is capable of measuring conventional and digital intraoral complete-arch impressions for 3D accuracy. A steel reference dentate model was fabricated and measured with a reference scanner (digital reference model). Conventional impressions were made from the reference model, poured with Type IV dental stone, scanned with the reference scanner, and exported as digital models. Additionally, digital impressions of the reference model were made and the digital models were exported. Precision was measured by superimposing the digital models within each group. Superimposing the digital models on the digital reference model assessed the trueness of each impression method. Statistical significance was assessed with an independent sample t test (α=.05). The reference scanner delivered high accuracy over the entire dental arch with a precision of 1.6 ±0.6 µm and a trueness of 5.3 ±1.1 µm. Conventional impressions showed significantly higher precision (12.5 ±2.5 µm) and trueness values (20.4 ±2.2 µm) with small deviations in the second molar region (P<.001). Digital impressions were significantly less accurate with a precision of 32.4 ±9.6 µm and a trueness of 58.6 ±15.8µm (P<.001). More systematic deviations of the digital models were visible across the entire dental arch. The new reference scanner is capable of measuring the precision and trueness of both digital and conventional complete-arch impressions. The digital impression is less accurate and shows a different pattern of deviation than the conventional impression. Copyright © 2013 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Basic investigation of the laminated alginate impression technique: Setting time, permanent deformation, elastic deformation, consistency, and tensile bond strength tests.

PubMed

Kitamura, Aya; Kawai, Yasuhiko

2015-01-01

Laminated alginate impression for edentulous is simple and time efficient compared to border molding technique. The purpose of this study was to examine clinical applicability of the laminated alginate impression, by measuring the effects of different Water/Powder (W/P) and mixing methods, and different bonding methods in the secondary impression of alginate impression. Three W/P: manufacturer-designated mixing water amount (standard), 1.5-fold (1.5×) and 1.75-fold (1.75×) water amount were mixed by manual and automatic mixing methods. Initial and complete setting time, permanent and elastic deformation, and consistency of the secondary impression were investigated (n=10). Additionally, tensile bond strength between the primary and secondary impression were measured in the following surface treatment; air blow only (A), surface baking (B), and alginate impression material bonding agent (ALGI-BOND: AB) (n=12). Initial setting times significantly shortened with automatic mixing for all W/P (p<0.05). The permanent deformation decreased and elastic deformation increased as high W/P, regardless of the mixing method. Elastic deformation significantly reduced in 1.5× and 1.75× with automatic mixing (p<0.05). All of these properties resulted within JIS standards. For all W/P, AB showed a significantly high bonding strength as compared to A and B (p<0.01). The increase of mixing water, 1.5× and 1.75×, resulted within JIS standards in setting time, suggesting its applicability in clinical setting. The use of automatic mixing device decreased elastic strain and shortening of the curing time. For the secondary impression application of adhesives on the primary impression gives secure adhesion. Copyright © 2014 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

What You Don't Know Won't Hurt Me: Impression Management Functions of Communication Channels in Relationships.

ERIC Educational Resources Information Center

O'Sullivan, Patrick B.

2000-01-01

Addresses the implications of interpersonal communication technology use for personal relationships. Tests elements of an impression management model, which specifies the processes and outcomes of strategic uses of channel and message for self-presentational goals. Supports a functional perspective that views mediated communication channels as a…

Sulcus depth reproduction with polyvinyl siloxane impression material: effects of hydrophilicity and impression temperature.

PubMed

Takahashi, Hidekazu; Finger, Werner J; Kurokawa, Rie; Furukawa, Masae; Komatsu, Masashi

2010-03-01

To determine the sulcus penetration ability of hydrophilic and hydrophobic polyvinyl siloxane (PVS) impression materials by impression technique, temperature, and sulcus width. Hydrophilic Flexitime (FLE; Heraeus Kulzer) and its hydrophobic counterpart (EXP) without surfactant were investigated, using light (L), monophase (M), and heavy (H) consistencies. A truncated steel cone surrounded by a 2-mm-deep and 50-, 100-, or 200-microm-wide sulcus, simulating the gingival tissue with agar, served as the test model. Impressions were made with single-mix (L or M) and double-mix (LM or LH) techniques at 23 degrees C and 37 degrees C, respectively. The reproduced sulcus heights were measured with a 3D laser scanner. Data were analyzed by ANOVA and Tukey HSD (P < .05). Irrespective of sulcus widths and temperature FLE-L penetrated deepest (> 1.9 mm); FLE-M, -LM, and-LH reproductions were shorter with narrow sulci. Reproductions of 50- and 100-microm sulci with EXP-L were shallower than with FLE-L. The shortest reproduction was, however, greater than 1.6 mm. In spite of some significant differences found in sulcus-reproducing ability with hydrophilic and hydrophobic impression materials applied at different impression-making temperatures and with different techniques, the practical relevance is limited.

49 CFR 195.577 - What must I do to alleviate interference currents?

Code of Federal Regulations, 2010 CFR

2010-10-01

... each impressed current or galvanic anode system to minimize any adverse effects on existing adjacent... 49 Transportation 3 2010-10-01 2010-10-01 false What must I do to alleviate interference currents... alleviate interference currents? (a) For pipelines exposed to stray currents, you must have a program to...

49 CFR 195.577 - What must I do to alleviate interference currents?

Code of Federal Regulations, 2011 CFR

2011-10-01

... each impressed current or galvanic anode system to minimize any adverse effects on existing adjacent... 49 Transportation 3 2011-10-01 2011-10-01 false What must I do to alleviate interference currents... alleviate interference currents? (a) For pipelines exposed to stray currents, you must have a program to...

Comparison of skin smears and biopsy specimens for demonstration of Leishmania tropica bodies in cutaneous leishmaniasis.

PubMed

Dar, Nasser Rashid; Khurshid, Tariq

2005-12-01

To determine and compare the diagnostic value of skin biopsy, saline aspirate smears, skin slit smears and skin biopsy impression smears to demonstrate Leishmania tropica (LT) bodies in cutaneous leishmaniasis and to determine any association within the applied diagnostic tests. An analytical study. Department of Dermatology, PNS Shifa, Karachi from January to December 2003. Seventyeight patients of cutaneous leishmaniasis were subjected to saline aspirate smears, skin slit smears, skin biopsy impression smears and skin biopsy and looked for LT bodies. The percentage positivity of all methods was calculated. McNemar test was applied to determine the association between percentage positivities of methods. Skin biopsy showed LT bodies in 70 (89.74%) patients, saline aspirate smears in 24 (30.76%), skin slit smears in 25 (32.05%) and skin biopsy impression smears in 27 (34.61%) patients. Smears demonstrated LT bodies in 10.25% cases in which biopsy was negative. Skin biopsy impression smears showed concordant results with skin biopsy in 20.51%, skin slit smears in 16.66% and saline aspirate smears in 19.25% of cases. Saline aspirate smears were positive in 48.1% of cases in which biopsy impression smears were negative, slit smears were positive in 50.9 % of cases in which biopsy impression smears were negative and slit smears were positive in 37% of cases in which saline aspirate smears were negative. Skin biopsy for histopathology is the most useful method in the demonstration of Leishmania parasite. Sensitivity of smears can be increased by a combination of various skin smears.

Comparative evaluation of border molding, using two different techniques in maxillary edentulous arches - An in vivo study

PubMed Central

Yarapatineni, Rameshbabu; Vilekar, Abhishek; Kumar, J Phani; Kumar, G Ajay; Aravind, Prasad; Kumar, P Anil

2013-01-01

Background: This study was undertaken to compare the retention between sectional border molding using low fusing greenstick compound and single step border molding using condensation silicone (putty) impression material in three stages- A. Immediately following border molding, B. After final impression and C. With the finished permanent denture base. Materials & Methods: In this study evaluation of retentive values of sectional border molding (Group I) (custom impression trays border molded with green stick compound ) and single step border molding (Group II) ( border molding with condensation silicone (putty) impression material ). In both techniques definitive wash impression were made with light body condensation silicone and permanent denture base with heat cure polymerization resin. Results: Group II was significantly higher (mean=8011.43) than Group I (mean=5777.43) in test-A. The t-value (1.5883) infers that there was significant difference between Group I and Group II (p =0.15). Group I was significantly higher (mean=6718.57) than Group II (mean=5224.29) in test -B. The t-value (1.6909) infers that there was significant difference between Group I and Group II (p=0.17). Group II was higher (mean=4025.14) than Group I (mean=3835.07) in test -C. The t-value was 0.1239. But it was found to be statistically insignificant (p=0.005). Conclusion: Within the limitation of this clinical study border molding custom tray with low fusing green stick compound provided similar retention as compared to custom impression tray with condensation silicone in permanent denture base. How to cite this article: Yarapatineni R, Vilekar A, Kumar JP, Kumar GA, Aravind P, Kumar PA. Comparative evaluation of border molding, using two different techniques in maxillary edentulous arches - An in vivo study. J Int Oral Health 2013; 5(6):82-7 . PMID:24453450

Toxoplasma gondii: history and diagnostic test development.

PubMed

Wyrosdick, Heidi M; Schaefer, John J

2015-12-01

Toxoplasma gondii is a protozoa that causes toxoplasmosis in people and other animals. It is considered one of the most common parasitic infections in the world due to its impressive range of hosts, widespread environmental contamination and the diverse means by which animals can be infected. Despite its ubiquity and numerous ongoing research efforts into both its basic biology and clinical management, many aspects of diagnosis and management of this disease are poorly understood. The range of diagnostic options that is available for veterinary diagnostic investigators are notably more limited than those available to medical diagnosticians, making accurate interpretation of each test result critical. The current review joins other reviews on the parasite with a particular emphasis on the history and continued development of diagnostic tests that are useful for veterinary diagnostic investigations. An understanding of the strengths and shortcomings of current diagnostic techniques will assist veterinary and public health officials in formulating effective treatment and control strategies in diverse animal populations.

Digital versus analog complete-arch impressions for single-unit premolar implant crowns: Operating time and patient preference.

PubMed

Schepke, Ulf; Meijer, Henny J A; Kerdijk, Wouter; Cune, Marco S

2015-09-01

Digital impression-making techniques are supposedly more patient friendly and less time-consuming than analog techniques, but evidence is lacking to substantiate this assumption. The purpose of this in vivo within-subject comparison study was to examine patient perception and time consumption for 2 complete-arch impression-making methods: a digital and an analog technique. Fifty participants with a single missing premolar were included. Treatment consisted of implant therapy. Three months after implant placement, complete-arch digital (Cerec Omnicam; Sirona) and analog impressions (semi-individual tray, Impregum; 3M ESPE) were made, and the participant's opinion was evaluated with a standard questionnaire addressing several domains (inconvenience, shortness of breath, fear of repeating the impression, and feelings of helplessness during the procedure) with the visual analog scale. All participants were asked which procedure they preferred. Operating time was measured with a stopwatch. The differences between impressions made for maxillary and mandibular implants were also compared. The data were analyzed with paired and independent sample t tests, and effect sizes were calculated. Statistically significant differences were found in favor of the digital procedure regarding all subjective domains (P<.001), with medium to large effect sizes. Of all the participants, over 80% preferred the digital procedure to the analog procedure. The mean duration of digital impression making was 6 minutes and 39 seconds (SD=1:51) versus 12 minutes and 13 seconds (SD=1:24) for the analog impression (P<.001, effect size=2.7). Digital impression making for the restoration of a single implant crown takes less time than analog impression making. Furthermore, participants preferred the digital scan and reported less inconvenience, less shortness of breath, less fear of repeating the impression, and fewer feelings of helplessness during the procedure. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

White light scanner-based repeatability of 3-dimensional digitizing of silicon rubber abutment teeth impressions

PubMed Central

Jeon, Jin-Hun; Lee, Kyung-Tak; Kim, Hae-Young; Kim, Ji-Hwan

2013-01-01

PURPOSE The aim of this study was to evaluate the repeatability of the digitizing of silicon rubber impressions of abutment teeth by using a white light scanner and compare differences in repeatability between different abutment teeth types. MATERIALS AND METHODS Silicon rubber impressions of a canine, premolar, and molar tooth were each digitized 8 times using a white light scanner, and 3D surface models were created using the point clouds. The size of any discrepancy between each model and the corresponding reference tooth were measured, and the distribution of these values was analyzed by an inspection software (PowerInspect 2012, Delcamplc., Birmingham, UK). Absolute values of discrepancies were analyzed by the Kruskal-Wallis test and multiple comparisons (α=.05). RESULTS The discrepancy between the impressions for the canine, premolar, and molar teeth were 6.3 µm (95% confidence interval [CI], 5.4-7.2), 6.4 µm (95% CI, 5.3-7.6), and 8.9 µm (95% CI, 8.2-9.5), respectively. The discrepancy of the molar tooth impression was significantly higher than that of other tooth types. The largest variation (as mean [SD]) in discrepancies was seen in the premolar tooth impression scans: 26.7 µm (95% CI, 19.7-33.8); followed by canine and molar teeth impressions, 16.3 µm (95% CI, 15.3-17.3), and 14.0 µm (95% CI, 12.3-15.7), respectively. CONCLUSION The repeatability of the digitizing abutment teeth's silicon rubber impressions by using a white light scanner was improved compared to that with a laser scanner, showing only a low mean discrepancy between 6.3 µm and 8.9 µm, which was in an clinically acceptable range. Premolar impression with a long and narrow shape showed a significantly larger discrepancy than canine and molar impressions. Further work is needed to increase the digitizing performance of the white light scanner for deep and slender impressions. PMID:24353885

Personality judgments from everyday images of faces

PubMed Central

Sutherland, Clare A. M.; Rowley, Lauren E.; Amoaku, Unity T.; Daguzan, Ella; Kidd-Rossiter, Kate A.; Maceviciute, Ugne; Young, Andrew W.

2015-01-01

People readily make personality attributions to images of strangers' faces. Here we investigated the basis of these personality attributions as made to everyday, naturalistic face images. In a first study, we used 1000 highly varying “ambient image” face photographs to test the correspondence between personality judgments of the Big Five and dimensions known to underlie a range of facial first impressions: approachability, dominance, and youthful-attractiveness. Interestingly, the facial Big Five judgments were found to separate to some extent: judgments of openness, extraversion, emotional stability, and agreeableness were mainly linked to facial first impressions of approachability, whereas conscientiousness judgments involved a combination of approachability and dominance. In a second study we used average face images to investigate which main cues are used by perceivers to make impressions of the Big Five, by extracting consistent cues to impressions from the large variation in the original images. When forming impressions of strangers from highly varying, naturalistic face photographs, perceivers mainly seem to rely on broad facial cues to approachability, such as smiling. PMID:26579008

Can we measure patients' perception during dental impressions? The Burdens in Dental Impression-Making Questionnaire - BiDIM-Q.

PubMed

Tsirogiannis, Panagiotis; Neophytou, Sophia; Reul, Anika; Heydecke, Guido; Reissmann, Daniel R

2017-01-01

To develop a reliable and valid instrument for the comprehensive assessment of patients' burdens during dental impression making, the Burdens in Dental Impression Making Questionnaire, BiDIM-Q. The item pool was generated in a convenience sample of 20 prosthodontic patients using semi-structured face-to-face interviews. The final instrument was tested in 145 consecutively recruited patients, and psychometric properties of the BiDIM-Q were determined. Four different impression materials were used according to the manufacturers' instructions and indications: alginate, c-silicone, polyvinylsiloxane, and polyether. The final BiDIM-Q consisting of 12 items showed sufficient reliability, indicated by Cronbach's alpha of .82 and an average inter-item correlation of .29. Validity was supported by Pearson correlation coefficients for the correlation between the instrument's total score with the patients' overall satisfaction rating (r=.63), and by the correlation matrix for the correlations of the patients' perceptions with the practitioners' satisfaction ratings. Overall, patient perceived burdens were low with highest burdens observed when using polyether in partially dentate patients for pick-up impressions, while lowest burdens were reported when using c-silicone for impressions of edentulous jaws. The BiDIM-Q is a reliable and valid tool for assessing patient-based process-related quality of care in dentistry allowing a deeper insight into patients' perspective during dental impression making. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Mechanical Properties of Elastomeric Impression Materials: An In Vitro Comparison

PubMed Central

De Angelis, Francesco; Caputi, Sergio; D'Amario, Maurizio; D'Arcangelo, Camillo

2015-01-01

Purpose. Although new elastomeric impression materials have been introduced into the market, there are still insufficient data about their mechanical features. The tensile properties of 17 hydrophilic impression materials with different consistencies were compared. Materials and Methods. 12 vinylpolysiloxane, 2 polyether, and 3 hybrid vinylpolyether silicone-based impression materials were tested. For each material, 10 dumbbell-shaped specimens were fabricated (n = 10), according to the ISO 37:2005 specifications, and loaded in tension until failure. Mean values for tensile strength, yield strength, strain at break, and strain at yield point were calculated. Data were statistically analyzed using one-way ANOVA and Tukey's tests (α = 0.05). Results. Vinylpolysiloxanes consistently showed higher tensile strength values than polyethers. Heavy-body materials showed higher tensile strength than the light bodies from the same manufacturer. Among the light bodies, the highest yield strength was achieved by the hybrid vinylpolyether silicone (2.70 MPa). Polyethers showed the lowest tensile (1.44 MPa) and yield (0.94 MPa) strengths, regardless of the viscosity. Conclusion. The choice of an impression material should be based on the specific physical behavior of the elastomer. The light-body vinylpolyether silicone showed high tensile strength, yield strength, and adequate strain at yield/brake; those features might help to reduce tearing phenomena in the thin interproximal and crevicular areas. PMID:26693227

Effects of Impression Material, Impression Tray Type, and Type of Partial Edentulism on the Fit of Cobalt-Chromium Partial Denture Frameworks on Initial Clinical Insertion: A Retrospective Clinical Evaluation.

PubMed

Baig, Mirza Rustum; Akbar, Jaber Hussain; Qudeimat, Muawia; Omar, Ridwaan

2018-02-15

To evaluate the effects of impression material, impression tray type, and type of partial edentulism (ie, Kennedy class) on the accuracy of fit of cobalt-chromium (Co-Cr) partial removable dental prostheses (PRDP) in terms of the number of fabricated frameworks required until the attainment of adequate fit. Electronic case documentations of 120 partially edentulous patients provided with Co-Cr PRDP treatment for one or both arches were examined. Statistical analyses of data were performed using analysis of variance and Tukey honest significant difference test to compare the relationships between the different factors and the number of frameworks that needed to be fabricated for each patient (α = .05). Statistical analysis of data derived from 143 records (69 maxillary and 74 mandibular) revealed no significant correlation between impression material, tray type, or Kennedy class and the number of construction attempts for the pooled or individual arch data (P ≥ .05). In PRDP treatment, alginate can be chosen as a first-choice material, and metal stock trays can be a preferred option for making final impressions to fabricate Co-Cr frameworks.

Modification of First Impression Formation and "Personality" by Manipulating Outer Appearance.

PubMed

Hüttner, Susanne-Marie; Linden, Michael

2017-01-01

Global impression is the first item in any psychopathological evaluation, as patients often elicit negative responses in other persons by a dysfunctional first impression formation. This can lead to interactional problems and stigmatization. This study tested to what degree the perception of "personality" can be changed by simple manipulations of the outer appearance of a person. A total of 92 persons were given two different photos of the same female, one with hair combed back and the other with "open" curly hair. For each picture they made ratings on the Bipolar MED Rating Scale, which asks for judgements on 23 emotional impressions. The rating on the "two" persons differed significantly for 16 of the 23 items. Curled open hair led to a more open-hearted and trusting impression, while the combed-back hair was perceived as more reserved, earnest, and defiant. Results were independent of age and gender. People come to far-reaching conclusions about the "personality" of other persons (first impression formation) based on the outer appearance. This opens treatment options for improving social interaction and fighting stigma in patients with mental disorders. © 2017 S. Karger AG, Basel.

An In Vitro Comparison of the Marginal Adaptation Accuracy of CAD/CAM Restorations Using Different Impression Systems.

PubMed

Shembesh, Marwa; Ali, Ala; Finkelman, Matthew; Weber, Hans-Peter; Zandparsa, Roya

2017-10-01

To compare the marginal adaptation of 3-unit zirconia fixed dental prostheses (FDPs) obtained from intraoral digital scanners (Lava True Definition, Cadent iTero), scanning of a conventional silicone impression, and the resulting master cast with an extraoral scanner (3Shape lab scanner). One reference model was fabricated from intact, non-carious, unrestored human mandibular left first premolar and first molar teeth (teeth #19 and 21), prepared for a three-unit all-ceramic FDP. Impressions of the reference model were obtained using four impression systems (n = 10), group 1 (PVS impression scan), group 2 (stone cast scan), group 3 (Cadent iTero), and group 4 (Lava True Defintion). Then the three-unit zirconia FDPs were milled. Marginal adaptation of the zirconia FDPs was evaluated using an optical comparator at four points on each abutment. The mean (SD) was reported for each group. One-way ANOVA was used to assess the statistical significance of the results, with post hoc tests conducted via Tukey's HSD. p < 0.05 was considered statistically significant. All analyses were done using SPSS 22.0. The mean (SD) marginal gaps for the recorded data from highest to lowest were silicone impression scans 81.4 μm (6.8), Cadent iTero scan 62.4 μm (5.0), master cast scan 50.2 μm (6.1), and Lava True definition scan 26.6 μm (4.7). One-way ANOVA revealed significant differences (p < 0.001) in the mean marginal gap among the groups. The Tukey's HSD tests demonstrated that the differences between all groups (silicone impression scan, master cast scan, Lava True definition scan, iTero Cadent scan) were statistically significant (all p < 0.001). On the basis of the criterion of 120 μm as the limit of clinical acceptance, all marginal discrepancy values of all groups were clinically acceptable. Within the confines of this in vitro study, it can be concluded that the marginal gap of all impression techniques was within the acceptable clinical limit (120 μm). Group 4 (Lava True Defintion) showed the lowest average gap among all groups followed by group 2 (stone cast scan), group 3 (Cadent iTero), and group 1 (PVS impression scan); these differences were statistically significant. © 2016 by the American College of Prosthodontists.

Effectiveness of Disinfectants on Antimicrobial and Physical Properties of Dental Impression Materials.

PubMed

Demajo, Jean Karl; Cassar, Valter; Farrugia, Cher; Millan-Sango, David; Sammut, Charles; Valdramidis, Vasilis; Camilleri, Josette

2016-01-01

The aim of this study was to assess the antimicrobial activity of chemical disinfectants on alginate and silicone impression materials. The effect of chemical disinfectants on the dimensional stability of the impression materials was also assessed. For the microbiologic assessment, impressions of the maxillary arch were taken from 14 participants, 7 using alginate and 7 using an addition silicone. The impressions were divided into three sections. Each section was subjected to spraying with MD 520 or Minuten or no disinfection (control), respectively. Antimicrobial action of the chemical disinfectants was assessed by measuring microbial counts in trypticase soy agar (TSA) media and expressing the results in colony-forming units/cm2. The surface area of the dental impressions was calculated by scanning a stone cast using computer-aided design/computer-assisted manufacture and analyzing the data using a custom computer program. The dimensional stability of the impression materials after immersion in disinfectants was assessed by measuring the linear displacement of horizontally restrained materials using a traveling microscope. The percent change in length over 3 hours was thus determined. Alginate exhibited a higher microbial count than silicone. MD 520 eliminated all microbes as opposed to Minuten. The bacterial growth after Minuten disinfection was almost twice as much for alginate than for addition silicone impressions. The chemical disinfectants affected the alginate dimensional stability. Minuten reduced the shrinkage sustained by alginate during the first hour of storage. Alginate harbors three times more microorganisms than silicone impression material. Chemical disinfection by glutaraldehyde-based disinfectant was effective in eliminating all microbial forms for both alginate and silicone without modifying the dimensional stability. Alcohol-based disinfectants, however, reduced the alginate shrinkage during the first 90 minutes of setting. The current studies also propose another method to report the surface area based on accurate estimation by 3D image analysis.

The impact of motivation on race-based impression formation.

PubMed

Li, Tianyi; Cardenas-Iniguez, Carlos; Correll, Joshua; Cloutier, Jasmin

2016-01-01

Affective biases toward racial out-group members, characterized by White perceivers' negative evaluations of Black individuals, prevail in U.S. culture. Such affective associations have been found to guide race-based impression formation. Accordingly, individuals may strive to resolve inconsistencies when perceiving targets violating their expectations. The current study focuses on the impact of evaluative incongruence on the activity of the dorsomedial prefrontal cortex (dmPFC) - a brain region previously shown to support impression formation. When asking participants to form impressions of positively and negatively evaluated Black and White individuals, we found preferential dmPFC activity in response to individuals paired with information that violates race-based affective associations. Importantly, individual differences in internal motivation to respond without prejudice (IMS) were found to shape the extent to which dmPFC activity indexes the interactive effects of race and affective associations during impression formation. Specifically, preferential dmPFC activity in response to evaluatively incongruent targets (i.e., Black-positive & White-negative) was present among participants with lower, but not those with higher, levels of IMS. Implications and future directions are discussed in the context of dmPFC involvement in social cognition. Copyright © 2015 Elsevier Inc. All rights reserved.

A comparative evaluation of intraoral and extraoral digital impressions: An in vivo study.

PubMed

Sason, Gursharan Kaur; Mistry, Gaurang; Tabassum, Rubina; Shetty, Omkar

2018-01-01

The accuracy of a dental impression is determined by two factors: "trueness" and "precision." The scanners used in dentistry are relatively new in market, and very few studies have compared the "precision" and "trueness" of intraoral scanner with the extraoral scanner. The aim of this study was to evaluate and compare accuracy of intraoral and extraoral digital impressions. Ten dentulous participants (male/female) aged 18-45 years with an asymptomatic endodontically treated mandibular first molars with adjacent teeth present were selected for this study. The prepared test tooth was measured using a digital Vernier caliper to obtain reference datasets. The tooth was then scanned using the intraoral scanner, and the extraoral scans were obtained using the casts made from the impressions. The datasets were divided into four groups and then statistically analyzed. The test tooth preparation was done, and dimples were made using a round diamond point on the bucco-occlusal, mesio-occlusal, disto-occlusal, and linguo-occlusal lines angles, and these were used to obtain reference datasets intraorally using a digital Vernier caliper. The test tooth was then scanned with the IO scanner (CS 3500, Carestream dental) thrice and also impressions were made using addition silicone impression material (3M™ ESPE) and dental casts were poured in Type IV dental stone (Kalrock-Kalabhai Karson India Pvt. Ltd., India) which were later scanned with the EO scanner (LAVA™ Scan ST Design system [3M™ ESPE]) thrice. The Datasets obtained from Intraoral and Extraoral scanner were exported to Dental Wings software and readings were obtained. Repeated measures ANOVA test was used to compare differences between the groups and independent t -test for comparison between the readings of intraoral and extraoral scanner. Least significant difference test was used for comparison between reference datasets with intraoral and extraoral scanner, respectively. A level of statistical significance of P < 0.05 was set. The precision values ranged from 20.7 to 33.35 μm for intraoral scanner and 19.5 to 37 μm for extraoral scanner. The mean deviations for intraoral scanner were 19.6 μm mesiodistally (MD) and 16.4 μm buccolingually (BL) and 24.0 μm MD and 22.5 μm BL for extraoral scanner. The mean values of the intraoral scanner (413 μm) for trueness were closest to the actual measurements (459 μm) than the extraoral scanner (396 μm). The intraoral scanner showed higher "precision" and "trueness" values when compared with the extraoral scanner.

Comparison of Accuracy Between a Conventional and Two Digital Intraoral Impression Techniques.

PubMed

Malik, Junaid; Rodriguez, Jose; Weisbloom, Michael; Petridis, Haralampos

To compare the accuracy (ie, precision and trueness) of full-arch impressions fabricated using either a conventional polyvinyl siloxane (PVS) material or one of two intraoral optical scanners. Full-arch impressions of a reference model were obtained using addition silicone impression material (Aquasil Ultra; Dentsply Caulk) and two optical scanners (Trios, 3Shape, and CEREC Omnicam, Sirona). Surface matching software (Geomagic Control, 3D Systems) was used to superimpose the scans within groups to determine the mean deviations in precision and trueness (μm) between the scans, which were calculated for each group and compared statistically using one-way analysis of variance with post hoc Bonferroni (trueness) and Games-Howell (precision) tests (IBM SPSS ver 24, IBM UK). Qualitative analysis was also carried out from three-dimensional maps of differences between scans. Means and standard deviations (SD) of deviations in precision for conventional, Trios, and Omnicam groups were 21.7 (± 5.4), 49.9 (± 18.3), and 36.5 (± 11.12) μm, respectively. Means and SDs for deviations in trueness were 24.3 (± 5.7), 87.1 (± 7.9), and 80.3 (± 12.1) μm, respectively. The conventional impression showed statistically significantly improved mean precision (P < .006) and mean trueness (P < .001) compared to both digital impression procedures. There were no statistically significant differences in precision (P = .153) or trueness (P = .757) between the digital impressions. The qualitative analysis revealed local deviations along the palatal surfaces of the molars and incisal edges of the anterior teeth of < 100 μm. Conventional full-arch PVS impressions exhibited improved mean accuracy compared to two direct optical scanners. No significant differences were found between the two digital impression methods.

Molecular Pathology and Personalized Medicine: The Dawn of a New Era in Companion Diagnostics-Practical Considerations about Companion Diagnostics for Non-Small-Cell-Lung-Cancer.

PubMed

Plönes, Till; Engel-Riedel, Walburga; Stoelben, Erich; Limmroth, Christina; Schildgen, Oliver; Schildgen, Verena

2016-01-15

Companion diagnostics (CDx) have become a major tool in molecular pathology and assist in therapy decisions in an increasing number of various cancers. Particularly, the developments in lung cancer have been most impressing in the last decade and consequently lung cancer mutation testing and molecular profiling has become a major business of diagnostic laboratories. However, it has become difficult to decide which biomarkers are currently relevant for therapy decisions, as many of the new biomarkers are not yet approved as therapy targets, remain in the status of clinical studies, or still have not left the experimental phase. The current review is focussed on those markers that do have current therapy implications, practical implications arising from the respective companion diagnostics, and thus is focused on daily practice.

Emotion in the Neutral Face: A Mechanism for Impression Formation?

PubMed Central

Adams, Reginald B.; Nelson, Anthony J.; Soto, José A.; Hess, Ursula; Kleck, Robert E.

2012-01-01

The current work examined contributions of emotion-resembling facial cues to impression formation. There exist common facial cues that make people look male or female, emotional, and from which we derive personality inferences. We first conducted a Pilot study to assess these effects. We found that neutral female versus neutral male faces were rated as more submissive, affiliative, naïve, honest, cooperative, babyish, fearful, happy, and less angry than neutral male faces. In our Primary Study, we then “warped” these same neutral faces over their corresponding anger and fear displays so the resultant facial appearance cues now structurally resembled emotion while retaining a neutral visage (e.g., no wrinkles, furrows, creases etc.). The gender effects found in the Pilot Study were replicated in the Primary Study, suggesting clear stereotype driven impressions. Critically, ratings of the neutral-over-fear warps versus neutral-over-anger warps also revealed a profile similar to the gender-based ratings, revealing perceptually driven impressions directly attributable to emotion overgeneralization. PMID:22471850

Accuracy, reliability, and efficiency of intraoral scanners for full-arch impressions: a systematic review of the clinical evidence.

PubMed

Goracci, Cecilia; Franchi, Lorenzo; Vichi, Alessandro; Ferrari, Marco

2016-08-01

The interest on intraoral scanners for digital impressions has been growing and new devices are continuously introduced on the market. It is timely to verify whether the several scanners proposed for full-arch digital impressions have been tested under clinical conditions for validity, repeatability, reproducibility, as well as for time efficiency, and patient acceptance. An electronic search of the literature was conducted through PubMed, Scopus, Cochrane Library, Web of Science, and Embase, entering the query terms 'digital impression', 'intraoral digital impression', 'intraoral scanning', 'intraoral scanner', 'intraoral digital scanner', combined by the Boolean operator 'OR'. No language or time limitation was applied. Only studies where digital full-arch impressions had been recorded intraorally were considered. In only eight studies full-arch scans had been performed intraorally. Only four studies reported data on validity, repeatability, reproducibility of digital measurements and their samples were limited to subjects in complete permanent dentition. Only two intraoral scanners, Lava COS and iTero, were tested. Scanning times were measured in six studies and varied largely. Patients' acceptance of intraoral scanning was evaluated in four studies, but it was not specifically assessed for children. The scientific evidence so far collected on intraoral scanning is neither exhaustive, nor up-to-date. Data from full-arch scans performed in children should be collected. For a meaningful assessment of time efficiency, agreement should be reached on the procedural steps to be included in the computation of scanning time. © The Author 2015. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.

46 CFR 120.370 - General grounding requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... hull must not carry current as a conductor except for the following systems: (1) Impressed current... grounding pole and a grounding conductor in the portable cord. (c) Each nonmetallic mast and top mast must have a lightning ground conductor. ...

46 CFR 120.370 - General grounding requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... hull must not carry current as a conductor except for the following systems: (1) Impressed current... grounding pole and a grounding conductor in the portable cord. (c) Each nonmetallic mast and top mast must have a lightning ground conductor. ...

46 CFR 120.370 - General grounding requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... hull must not carry current as a conductor except for the following systems: (1) Impressed current... grounding pole and a grounding conductor in the portable cord. (c) Each nonmetallic mast and top mast must have a lightning ground conductor. ...

46 CFR 120.370 - General grounding requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... hull must not carry current as a conductor except for the following systems: (1) Impressed current... grounding pole and a grounding conductor in the portable cord. (c) Each nonmetallic mast and top mast must have a lightning ground conductor. ...

46 CFR 120.370 - General grounding requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... hull must not carry current as a conductor except for the following systems: (1) Impressed current... grounding pole and a grounding conductor in the portable cord. (c) Each nonmetallic mast and top mast must have a lightning ground conductor. ...

The Effects of Interior Design on Communication and Impressions of a Counselor in a Counseling Room

ERIC Educational Resources Information Center

Miwa, Yoshiko; Hanyu, Kazunori

2006-01-01

This study aimed to investigate effects of the interior design of a counseling room on participants' self-disclosure and impressions of a counselor. The authors examined the effects of lighting and decorations. It tested four conditions crossing decorations (with or without home-like decorations) and type of lighting (bright or dim). Eighty…

Trainees' Perceived Knowledge Gain Unrelated to the Training Domain: The Joint Action of Impression Management and Motives

ERIC Educational Resources Information Center

Chiaburu, Dan S.; Huang, Jason L.; Hutchins, Holly M.; Gardner, Richard G.

2014-01-01

Trainees' knowledge gains represent an important outcome in human resource development. In this research, we tested a model examining the joint influence of social desirability (impression management, self-deception) and motives (need for power, need for approval) on trainees' self-reported knowledge gain. We conducted a study with…

Doing Good Is a Hustle, Too: Effects of Motives To Impression Manage, Communication Style, and Licensing on the Reputation of the Public Relations Practitioner.

ERIC Educational Resources Information Center

Sallot, Lynne M.

A study tested effects of motives, communication style, and licensing (whether the practitioner is licensed or not) on public relations practitioners' reputations. Impression management theory suggests that perceived motives and self-interests may explain the poor reputation sometimes attributed to public relations practitioners. Subjects, 585…

Ultrasonic monitoring of the setting of silicone elastomeric impression materials.

PubMed

Kanazawa, Tomoe; Murayama, Ryosuke; Furuichi, Tetsuya; Imai, Arisa; Suda, Shunichi; Kurokawa, Hiroyasu; Takamizawa, Toshiki; Miyazaki, Masashi

2017-01-31

This study used an ultrasonic measurement device to monitor the setting behavior of silicone elastomeric impression materials, and the influence of temperature on setting behavior was determined. The ultrasonic device consisted of a pulser-receiver, transducers, and an oscilloscope. The two-way transit time through the mixing material was divided by two to account for the down-and-back travel path; then it was multiplied by the sonic velocity. Analysis of variance and the Tukey honest significant difference test were used. In the early stages of the setting process, most of the ultrasonic energy was absorbed by the elastomers and the second echoes were relatively weak. As the elastomers hardened, the sonic velocities increased until they plateaued. The changes in sonic velocities varied among the elastomers tested, and were affected by temperature conditions. The ultrasonic method used in this study has considerable potential for determining the setting processes of elastomeric impression materials.

Effect of implant angulation and impression technique on impressions of NobelActive implants.

PubMed

Alexander Hazboun, Gillian Brewer; Masri, Radi; Romberg, Elaine; Kempler, Joanna; Driscoll, Carl F

2015-05-01

How the configuration of the NobelActive internal conical connection affects implant impressions is uncertain. The purpose of this study was to measure the effect in vitro of closed and open tray impression techniques for NobelActive implants placed at various angulations. Six NobelActive implants were placed in a master maxillary cast as follows: 0 degrees of angulation to a line drawn perpendicular to the occlusal plane in the first molar area, 15 degrees of angulation to a line drawn perpendicular to the occlusal plane in the first premolar area, and 30 degrees of angulation to a line drawn perpendicular to the occlusal plane in the lateral incisor area. Twelve open tray and 12 closed tray impressions were made. Occlusal, lateral, and frontal view photographs of the resulting casts were used to measure the linear and angular displacement of implant analogs. Statistical analysis was performed with a factorial analysis of variance (ANOVA), followed by the Tukey HSD test (α=.05). No significant difference was found in the impressions made of NobelActive implants with the open or closed tray technique (linear displacement: F=0.93, P=.34; angular displacement: F=2.09, P=.15). In addition, implant angulation (0, 15, or 30 degrees) had no effect on the linear or angular displacement of impressions (linear displacement: F=2.72, P=.07; angular displacement: F=0.86, P=.43). Finally, no significant interaction was found between impression technique and implant angulation on NobelActive implants (F=0.25, P=.77; F=1.60, P=.20). Within the limitations of this study, impression technique (open vs closed tray) and implant angulation (0, 15, and 30 degrees) had no significant effect on in vitro impressions of NobelActive implants. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Three-dimensional accuracy of different impression techniques for dental implants

PubMed Central

Nakhaei, Mohammadreza; Madani, Azam S; Moraditalab, Azizollah; Haghi, Hamidreza Rajati

2015-01-01

Background: Accurate impression making is an essential prerequisite for achieving a passive fit between the implant and the superstructure. The aim of this in vitro study was to compare the three-dimensional accuracy of open-tray and three closed-tray impression techniques. Materials and Methods: Three acrylic resin mandibular master models with four parallel implants were used: Biohorizons (BIO), Straumann tissue-level (STL), and Straumann bone-level (SBL). Forty-two putty/wash polyvinyl siloxane impressions of the models were made using open-tray and closed-tray techniques. Closed-tray impressions were made using snap-on (STL model), transfer coping (TC) (BIO model) and TC plus plastic cap (TC-Cap) (SBL model). The impressions were poured with type IV stone, and the positional accuracy of the implant analog heads in each dimension (x, y and z axes), and the linear displacement (ΔR) were evaluated using a coordinate measuring machine. Data were analyzed using ANOVA and post-hoc Tukey tests (α = 0.05). Results: The ΔR values of the snap-on technique were significantly lower than those of TC and TC-Cap techniques (P < 0.001). No significant differences were found between closed and open impression techniques for STL in Δx, Δy, Δz and ΔR values (P = 0.444, P = 0.181, P = 0.835 and P = 0.911, respectively). Conclusion: Considering the limitations of this study, the snap-on implant-level impression technique resulted in more three-dimensional accuracy than TC and TC-Cap, but it was similar to the open-tray technique. PMID:26604956

An in vitro investigation into the physical properties of irreversible hydrocolloid alternatives.

PubMed

Patel, Rishi D; Kattadiyil, Mathew T; Goodacre, Charles J; Winer, Myron S

2010-11-01

A number of manufacturers have introduced new products that are marketed as alternatives to irreversible hydrocolloid impression materials. However, there is a paucity of laboratory and clinical research on these products compared to traditional irreversible hydrocolloid. The purpose of this study was to evaluate the detail reproduction, gypsum compatibility, and linear dimensional change of 3 recently introduced impression materials designed as alternatives to irreversible hydrocolloid. The tested materials were Position Penta Quick, Silgimix, and AlgiNot. An irreversible hydrocolloid impression material, Jeltrate Plus Antimicrobial, served as the control. The parameters of detail reproduction, gypsum compatibility, and linear dimensional change were tested in accordance with ANSI/ADA Specifications No. 18 and 19. The gypsum compatibility was tested using a type III stone (Microstone Golden) and a type IV stone (Die-Keen Green). The data were analyzed using the Kruskal-Wallis rank test and the Mann-Whitney U test (α=.05). The test materials demonstrated significantly (P<.001) better detail reproduction than the control material. Silgimix exhibited the best compatibility with Microstone, whereas AlgiNot and Position Penta Quick exhibited the best gypsum compatibility with Die-Keen. An incompatibility was observed over time between the Jeltrate control material and the Microstone gypsum material. For linear dimensional change, the mean dimension of the control material most closely approximated the distance between the lines on the test die, but it exhibited the greatest variability in measurements. All of the test materials exhibited linear dimensional change within the ADA's accepted limit of 1.0%. The 3 new impression materials exhibited better detail reproduction and less variability in linear dimensional change than the irreversible hydrocolloid control. Gypsum compatibility varied with the brand of gypsum used, with an incompatibility identified between the control material (Jeltrate Plus Antimicrobial) and Microstone related to surface changes observed over time. Copyright © 2010 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

A Comparative Evaluation of Accuracy of the Dies Affected by Tray Type, Material Viscosity, and Pouring Sequence of Dual and Single Arch Impressions- An In vitro Study

PubMed Central

Kulkarni, Rahul S.; Shah, Rupal J.; Chhajlani, Rahul; Saklecha, Bhuwan; Maru, Kavita

2017-01-01

Introduction The clinician’s skill, impression techniques, and materials play a very important role in recording fine details in an impression for accuracy of fixed partial denture prosthesis. Impression of prepared teeth and of the opposing arch can be recorded simultaneously by dual-arch trays, while the full arch metal trays are used for impressions of prepared teeth in one arch. Aim To measure and compare the accuracy of working dies made from impressions with metal and plastic dual arch trays and metal full arch trays, for two viscosities of impression material and by changing the sequence of pour of working and non-working sides. Materials and Methods A balanced design with independent samples was used to study the three variables (tray type, impression material viscosity, and pouring sequence). An impression made by dual arch trays and single arch trays were divided in to three groups (Group A-plastic dual arch tray, Group B-metal dual arch tray, Group C-full arch metal stock tray). Out of these three groups, two groups (Group A and B) were subdivided in to four subgroups each and one group (Group C) was subdivided in to two subgroups. A sample size of 30 was used in each subgroup yielding a total 300 impressions in three groups or ten subgroups. Impressions were made of a machined circular stainless steel die. All three dimensions (Occlusogingival, Mesiodistal, and Buccolingual) of the working dies as well as stainless steel standard die were measured three times, and the mean was used for the three standard sample values to which all working dies means were compared. Statistical analysis used for this study was a 3-factor analysis of variance with hypothesis testing at α =0.05. Results With respect to the selection of impression material viscosity statistically significant differences were found in the dies for the buccolingual and mesiodistal dimensions. Metal dual arch trays were slightly more accurate in the mesiodistal dimension in comparison to the plastic trays in reference of tray selection and in view of pouring sequence no differences were observed in occlusogingival dimension but in buccolingual and mesiodistal dimensions nonworking side was more accurate. Conclusion The gypsum dies produced from the dual arch impressions were generally smaller in all three dimensions than the stainless steel standard die. Plastic dual-arch trays were more accurate with rigid impression material and there was not statistically significant difference for sequence of pouring. Metal dual-arch trays were more accurate with monophase impression material and working side was more accurate. Stock metal full arch trays were more accurate for monophase impression material. PMID:28571280

Dynamic field theory and executive functions: lending explanation to current theories of development.

PubMed

Morton, J Bruce

2014-06-01

Buss and Spencer's monograph is an impressive achievement that is sure to have a lasting impact on the field of child development. The dynamic field theory (DFT) model that forms the heart of this contribution is ambitious in scope, detailed in its implementation, and rigorously tested against data, old and new. As such, the ideas contained in this fine document represent a qualitative advance in our understanding of young children's behavior, and lay a foundation for future research into the developmental origins of executive functioning. © 2014 The Society for Research in Child Development, Inc.

Looks and linguistics: Impression formation in online exchange marketplaces.

PubMed

Ciuchta, Michael P; O'Toole, Jay

2016-01-01

This study advances theories of impression formation by focusing on two factors that generate emotional responses: physical attractiveness and positive word use. Although considerable research on impression formation exists, most studies consider factors in isolation and neglect possible interactions. Our theory introduces competing mechanisms regarding possible interaction effects, and we empirically test them in an online marketplace. Results from the analysis of 729 loan requests from a leading online peer-to-peer lending market suggest that physical attractiveness and positive word use work together to influence the likelihood of acquiring resources and establish an important boundary condition to the general "beauty is good" effect.

Accuracy of Multiple Pour Cast from Various Elastomer Impression Methods

PubMed Central

Saad Toman, Majed; Ali Al-Shahrani, Abdullah; Ali Al-Qarni, Abdullah

2016-01-01

The accurate duplicate cast obtained from a single impression reduces the profession clinical time, patient inconvenience, and extra material cost. The stainless steel working cast model assembly consisting of two abutments and one pontic area was fabricated. Two sets of six each custom aluminum trays were fabricated, with five mm spacer and two mm spacer. The impression methods evaluated during the study were additional silicone putty reline (two steps), heavy-light body (one step), monophase (one step), and polyether (one step). Type IV gypsum casts were poured at the interval of one hour, 12 hours, 24 hours, and 48 hours. The resultant cast was measured with traveling microscope for the comparative dimensional accuracy. The data obtained were subjected to Analysis of Variance test at significance level <0.05. The die obtained from two-step putty reline impression techniques had the percentage of variation for the height −0.36 to −0.97%, while diameter was increased by 0.40–0.90%. The values for one-step heavy-light body impression dies, additional silicone monophase impressions, and polyether were −0.73 to −1.21%, −1.34%, and −1.46% for the height and 0.50–0.80%, 1.20%, and −1.30% for the width, respectively. PMID:28096815

First impression versus extended usage: a comparison of product testing methodologies for perfume.

PubMed

Shalofsky, I

1993-04-01

Synopsis In the fine fragrance industry, unlike many other fast moving consumer goods (fmcg) industries, systematic consumer product-testing has usually been conspicuous by its absence. The reasons are varied, including perfume's own traditions rooted in fashion rather than in marketing, the reluctance of perfumers to see their creations tested, the frequently (and perhaps, surprisingly) short lead times accorded for new product development and, of course, costs. When consumer product-testing is carried out, it is often limited for these same reasons, to 'sniff-testing', which, in the perfume industry, is equivalent to 'first impression' testing. This paper suggests that such sniff-testing may not only be unreliable, but perhaps more unreliable for the perfume category than has been realized hitherto. Reference is made to two consumer research studies on perfume, a qualitative project in France, followed by a quantitative exercise in the UK. A comparison is made between in-home test and sniff-test results for the same set of perfumes, which illustrates the limitations of sniff-testing in general, and the misleading results that it may produce, in particular. A major implication is that perfume is one product category which should be tested in extended usage, and not just for 'first impressions'. Résumé Dans l'industrie de la parfumerie fine, contrairement aux autres industries de produits de grande consommation, les tests consommateurs systématiques sont rarement utilisés. Les raisons sont diverses; les traditions propres du parfum tournées vers la mode plutôt que vers le marketing, le refus des parfumeurs de voir leurs créations subir des tests, les délais étonnamment courts pour le développement d'un nouveau produit et, bien sûr, le coût. Lorsqu'un test consommateurs est effectué, il se résume généralement pour ces mêmes raisons, en un test 'sniff', ce qui, dans l'industrie du parfum équivaut à un test de 'première impression'. Cet article montre que ces tests 'sniff' sont encore moins fiables pour le parfum que l'on avait pensé jusqu'à maintenant. Il est fait référence à deux tests consommateurs sur le parfum, un projet qualitatif en France, suivi par un exercice quantitatif effectué en Grande Bretagne. La comparaison entre les tests réalisés à domicile d'une part, et en sale d'autre part, montre que, pour les mêmes parfums, les résultats obtenus peuvent être erronés. Une des conclusions principales est que le parfum est un produit qui devrait être testé sur une longue période et non pas sur une première impression.

Assessment of auditory impression of the coolness and warmness of automotive HVAC noise.

PubMed

Nakagawa, Seiji; Hotehama, Takuya; Kamiya, Masaru

2017-07-01

Noise induced by a heating, ventilation and air conditioning (HVAC) system in a vehicle is an important factor that affects the comfort of the interior of a car cabin. Much effort has been devoted to reduce noise levels, however, there is a need for a new sound design that addresses the noise problem from a different point of view. In this study, focusing on the auditory impression of automotive HVAC noise concerning coolness and warmness, psychoacoustical listening tests were performed using a paired comparison technique under various conditions of room temperature. Five stimuli were synthesized by stretching the spectral envelopes of recorded automotive HVAC noise to assess the effect of the spectral centroid, and were presented to normal-hearing subjects. Results show that the spectral centroid significantly affects the auditory impression concerning coolness and warmness; a higher spectral centroid induces a cooler auditory impression regardless of the room temperature.

Making a Visual Impression (or Not): Current Design Practices of Nutritional Websites.

PubMed

Lazard, Allison J; Dudo, Anthony; Dennis, Tessa; Ewald, Mary Grace; Love, Brad

2017-04-01

Understanding the influence of visual design, as the access point for online health communication, is key as Americans are increasingly sickened by an obesity epidemic. Nutritional websites that deliver critical health information should be considered as a potential strategy to fight against the grave consequences of obesity, as research indicates that consumers are consistently turning to the Internet as a resource for health information. Focusing on nutritional websites, this study analyzes the use of visual design principles that are known to greatly influence first impressions and appeal of the information from the user's perspective. The results suggest there are opportunities for improvement to the online communication of nutritional information to increase the likelihood of users' favorable first impressions, the critical first steps for nutritional information delivery goals.

[Asymmetric confusability effects in recognition memory of line drawings].

PubMed

Uchino, Y; Hakoda, Y; Yamada, N

2000-06-01

Experiment 1 and 2 examined the effect of addition or deletion changes in a picture recognition test. Addition and deletion applied to original pictures were referred to deviation change, and addition to deleted pictures or deletion from added pictures was referred to restoration change. In Experiment 1 (n = 40), elaborative detailed information contained in line drawings of scenes was changed whereas one of major features in a single object was changed in Experiment 2 (n = 36). In the test phase, participants indicated whether each test picture was changed or not from the picture they had seen in the study phase. Deviation change had a greater effect on detection performance than restoration only in Experiment 2. Additions were easily detected than deletions only in deviation change in Experiment 2. In Experiment 3, 51 participants rated impression of added or deleted pictures used in Experiment 2. Impression of added pictures was significantly different from that of deleted in 3 factors. These results suggest that superiority of additions over deletions might be due to their different impression change.

The influence of main bar corrosion on bond strength in selfcompacting concrete

NASA Astrophysics Data System (ADS)

Ayop, S. S.; Emhemed, A. N. K.; Jamaluddin, N.; Sadikin, A.

2017-11-01

The experimental study was conducted to determine the influence of main bar corrosion on bond strength in self-compacting concrete (SCC). A total 16 tension pullout tests specimens reinforced with 10 mm and 14 mm diameter bar were used for the bond strength test. The properties of SCC were determined from the slump flow, T50cm, V-funnel and L box test. Reinforcing bars in the concrete were submitted to impressed current to accelerate the corrosion of the bar. It was found that the relationship between bond strength and concrete strength in un-corroded specimens differed from that of corroded specimens set in high-strength concrete because of brittleness in the corroded specimens, which caused a sudden loss of bond strength. The results revealed that specimens of un-corroded and corroded showed a higher percentage of bond strength degradation during the pullout tests.

Effect of storage time of extended-pour and conventional alginate impressions on dimensional accuracy of casts.

PubMed

Rohanian, Ahmad; Ommati Shabestari, Ghasem; Zeighami, Somayeh; Samadi, Mohammad Javad; Shamshiri, Ahmad Reza

2014-11-01

Some manufacturers claim to have produced new irreversible hydro-colloids that are able to maintain their dimensional stability during storage. The present study evaluated the effect of storage time on dimensional stability of three alginates: Hydrogum 5, Tropicalgin and Alginoplast. In this experimental in-vitro trial, a total of 90 alginate impressions were made from a Dentoform model using Hydrogum 5, Tropicalgin and Alginoplast alginates. The impressions were stored in a sealed plastic bag without a damp paper towel for 0, 24, 48, 72 and 120 hours and then poured with type III dental stone. Cross-arch (facial of 6 to facial of 6 on the opposite side) and antero-posterior (distal of right first molar to the ipsilateral central incisor) measurements were made with a digital caliper on the casts. Data were analyzed by two-way and one-way ANOVA and Tukey's post-hoc test (P<0.05). Alginate type and the pouring time significantly affected the dimensional stability of alginate impressions (both Ps<0.001). Pouring of Hydrogum 5 impressions can be delayed for up to 120 hours without significant dimensional changes. Alginoplast impressions may be poured after 72 hours, but Tropicalgin should be poured immediately and the storage time should not be more than 24 hours. Immediate pouring of alginate impressions provides the highest accuracy in reproducing the teeth and adjacent tissues; however, this study demonstrated that pouring may be delayed for up to five days using extended-pour (Hydrogum 5) alginates.

Accuracy of a reformulated fast-set vinyl polysiloxane impression material using dual-arch trays.

PubMed

Kang, Alex H; Johnson, Glen H; Lepe, Xavier; Wataha, John C

2009-05-01

A common technique used for making crown impressions involves use of a vinyl polysiloxane impression material in combination with a dual-arch tray. A leading dental manufacturer has reformulated its vinyl polysiloxane (VPS) impression line, but the accuracy of the new material has not been verified. The purpose of this study was to assess the accuracy of reformulated VPS impression materials using the single-step dual-arch impression technique. Dual-arch impressions were made on a typodont containing a master stainless steel standard crown preparation die, from which gypsum working dies were formed, recovered, and measured. The impression materials evaluated were Imprint 3 Penta Putty with Quick Step Regular Body (IP-0); Imprint 3 Penta Quick Step Heavy Body with Quick Step Light Body (IP-1); Aquasil Ultra Rigid Fast Set with LV Fast Set (AQ-1); and Aquasil Ultra Heavy Fast Set with XLV Fast Set (AQ-2) (n=10). All impressions were disinfected with CaviCide spray for 10 minutes prior to pouring with type IV gypsum. Buccolingual (BL), mesiodistal (MD), and occlusogingival (OG) dimensions were measured and compared to the master die using an optical measuring microscope. Linear dimensional change was also assessed for IP-0 and AQ-1 at 1 and 24 hours based on ANSI/ADA Specification No. 19. Single-factor ANOVA with Dunnett's T3 multiple comparisons was used to compare BL, MD, and OG changes, with hypothesis testing at alpha=.05. A repeated-measures ANOVA was used to compare linear dimensional changes. There were statistical differences among the 4 impression systems for 3 of 4 dimensions of the master die. IP-0 working dies were significantly larger in MD and OG-L dimensions but significantly smaller in the BL dimension. IP-1 working dies were significantly smaller in the BL dimension compared to the master die. With the exception of IP-0, differences detected were small and clinically insignificant. No significant differences were observed for linear dimensional change. The single-step dual-arch impression technique produced working dies that were smaller in 3 of the 4 dimensions measured and may require additional die relief to achieve appropriate fit of cast restorations. Overall accuracy was acceptable for all impression groups with the exception of IP-0.

General Practitioners' Clinical Impression in the Screening for Frailty: Data From the FAP Study Pilot.

PubMed

Fougère, Bertrand; Sirois, Marie-Josée; Carmichael, Pierre-Hugues; Batomen-Kuimi, Brice-Lionel; Chicoulaa, Bruno; Escourrou, Emile; Nourhashémi, Fati; Oustric, Stéphane; Vellas, Bruno

2017-02-01

The progression of frailty is marked by an increased risk of adverse health outcomes in the elderly including falls, physical and/or cognitive disability, hospitalizations, and mortality. In primary care, the general practitioner's (GP's) clinical impression about their elderly patients' frailty state seems to be a key point in identifying frail individuals in their clinical practice. The aim of this article is to examine if GPs' clinical impressions regarding frailty concurs with objective measures of the gold standard frailty phenotype as described by Fried in community-dwelling older persons. Cross-sectional study in 14 primary care GP offices in the Toulouse area from May 1st to October 31st, 2015. Fourteen GPs screened their patients ≥70 years old. GPs' "frailty impression" was based on the Gérontopôle Frailty Screening Tool. "Objective measures of the five Fried frailty criteria" were obtained by a geriatric nurse through standardized testing. The capacity of the GPs' clinical impression to detect participants objectively measured as frail was examined with diagnostic values of observed sensitivity (Se), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV). A total of 268 participants were screened by GPs and assessed by a nurse. Mean age was 81 years and 62.3% were female. According to the objective measures of Fried's criteria, frailty (three to five criteria) and pre-frailty (one to two criteria) states were identified in 31% and 45.2% of participants, respectively. The Se of the GPs' impression was good (80.39%; 95% confidence interval [CI], 74.27%-85.61%), and the Sp was moderate (64.06%; 95% CI, 5.10%-75.68%). The overall PPV of the GPs' impression was 87.70% (95% CI, 82.12%-92.04%), and the NPV was 50.51% (95% CI, 39.27%-61.91%). Although the PPV increased with age reaching 93.33% (95% CI, 85.12%-97.80%) among patients ≥ 85 years old, the NPV decreased accordingly to a minimal 21.43% (95% CI, 4.66%-50.80%) in that subgroup. The present study highlights the importance of the GPs' clinical impression on frailty as a fair means to identify this syndrome in community-dwelling older patients in primary care. This clinical impression may not be sufficient, however, and some objective tests could be added to improve the accuracy of frailty detection in older patients in primary care. Copyright © 2016 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

Impression management during evaluation and psychological reactions post-donation of living kidney donors.

PubMed

Hildebrand, Lee; Melchert, Timothy P; Anderson, Rebecca C

2014-08-01

Many healthcare providers have been concerned about the extent to which potential kidney donors use impression management or concealment of important information regarding their medical history, current functioning, or other circumstances that could affect whether they are accepted as donors. To date, however, there has been very little empirical examination of these questions. It is also not known whether donors' use of impression management pre-donation is related to their reactions and adjustment post-donation. This study surveyed 76 individuals who had donated a kidney one to six yr previously regarding their use of impression management and their concealing of information during their psychological evaluations. They were also asked about their reactions to the donation and whether they would make the same decision again. In addition, 21 of these donors participated in focus groups that explored these questions in depth. Many of the kidney donors reported that they possessed very strong motivation to donate and consequently used impression management in their interactions with medical professionals pre-donation. Very few donors, however, indicated that they concealed information during their pre-donation evaluations. The donors' psychological reactions post-donation were generally positive, and nearly all indicated that they would make the same decision again. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Accuracy of a separating foil impression using a novel polyolefin foil compared to a custom tray and a stock tray technique

PubMed Central

Pastoret, Marie-Hélène; Bühler, Julia; Weiger, Roland

2017-01-01

PURPOSE To compare the dimensional accuracy of three impression techniques- a separating foil impression, a custom tray impression, and a stock tray impression. MATERIALS AND METHODS A machined mandibular complete-arch metal model with special modifications served as a master cast. Three different impression techniques (n = 6 in each group) were performed with addition-cured silicon materials: i) putty-wash technique with a prefabricated metal tray (MET) using putty and regular body, ii) single-phase impression with custom tray (CUS) using regular body material, and iii) two-stage technique with stock metal tray (SEP) using putty with a separating foil and regular body material. All impressions were poured with epoxy resin. Six different distances (four intra-abutment and two inter-abutment distances) were gauged on the metal master model and on the casts with a microscope in combination with calibrated measuring software. The differences of the evaluated distances between the reference and the three test groups were calculated and expressed as mean (± SD). Additionally, the 95% confidence intervals were calculated and significant differences between the experimental groups were assumed when confidence intervals did not overlap. RESULTS Dimensional changes compared to reference values varied between -74.01 and 32.57 µm (MET), -78.86 and 30.84 (CUS), and between -92.20 and 30.98 (SEP). For the intra-abutment distances, no significant differences among the experimental groups were detected. CUS showed a significantly higher dimensional accuracy for the inter-abutment distances with -0.02 and -0.08 percentage deviation compared to MET and SEP. CONCLUSION The separation foil technique is a simple alternative to the custom tray technique for single tooth restorations, while limitations may exist for extended restorations with multiple abutment teeth. PMID:28874996

Evaluation of impression accuracy for a four-implant mandibular model--a digital approach.

PubMed

Stimmelmayr, Michael; Erdelt, Kurt; Güth, Jan-Frederik; Happe, Arndt; Beuer, Florian

2012-08-01

Implant-supported prosthodontics requires precise impressions to achieve a passive fit. Since the early 1990s, in vitro studies comparing different implant impression techniques were performed, capturing the data mostly mechanically. The purpose of this study was to evaluate the accuracy of three different impression techniques digitally. Dental implants were inserted bilaterally in ten polymer lower-arch models at the positions of the first molars and canines. From each original model, three different impressions (A, transfer; B, pick-up; and C, splinted pick-up) were taken. Scan-bodies were mounted on the implants of the polymer and on the lab analogues of the stone models and digitized. The scan-body in position 36 (FDI) of the digitized original and master casts were each superimposed, and the deviations of the remaining three scan-bodies were measured three-dimensionally. The systematic error of digitizing the models was 13 μm for the polymer and 5 μm for the stone model. The mean discrepancies of the original model to the stone casts were 124 μm (±34) μm for the transfer technique, 116 (±46) μm for the pick-up technique, and 80 (±25) μm for the splinted pick-up technique. There were statistically significant discrepancies between the evaluated impression techniques (p ≤ 0.025; ANOVA test). The splinted pick-up impression showed the least deviation between original and stone model; transfer and pick-up techniques showed similar results. For better accuracy of implant-supported prosthodontics, the splinted pick-up technique should be used for impressions of four implants evenly spread in edentulous jaws.

Comparison of Dimensional Accuracy between Open-Tray and Closed-Tray Implant Impression Technique in 15° Angled Implants

PubMed Central

Balouch, F; Jalalian, E; Nikkheslat, M; Ghavamian, R; Toopchi, Sh; Jallalian, F; Jalalian, S

2013-01-01

Statement of Problem: Various impression techniques have different effects on the accuracy of final cast dimensions. Meanwhile; there are some controversies about the best technique. Purpose: This study was performed to compare two kinds of implant impression methods (open tray and closed tray) on 15 degree angled implants. Materials and Method: In this experimental study, a steel model with 8 cm in diameter and 3 cm in height were produced with 3 holes devised inside to stabilize 3 implants. The central implant was straight and the other two implants were 15° angled. The two angled implants had 5 cm distance from each other and 3.5 cm from the central implant. Dental stone, high strength (type IV) was used for the main casts. Impression trays were filled with poly ether, and then the two impression techniques (open tray and closed tray) were compared. To evaluate positions of the implants, each cast was analyzed by CMM device in 3 dimensions (x,y,z). Differences in the measurements obtained from final casts and laboratory model were analyzed using t-Test. Results: The obtained results indicated that closed tray impression technique was significantly different in dimensional accuracy when compared with open tray method. Dimensional changes were 129 ± 37μ and 143.5 ± 43.67μ in closed tray and open tray, while coefficient of variation in closed- tray and open tray were reported to be 27.2% and 30.4%, respectively. Conclusion: Closed impression technique had less dimensional changes in comparison with open tray method, so this study suggests that closed tray impression technique is more accurate. PMID:24724130

Comparative Evaluation of the Antimicrobial Efficacy of Three Immersion Chemical Disinfectants on Clinically Derived Poly(Vinyl Siloxane) Impressions.

PubMed

Jeyapalan, Vidhya; Krishnan, Chitra Shankar; Ramasubramanian, Hariharan; Sampathkumar, Jayakrishnakumar; Azhagarasan, N S; Krishnan, Madhusudan

2016-07-06

To comparatively evaluate the antimicrobial efficacy of freshly prepared electrolyzed oxidizing water (EOW) with that of 2.4% glutaraldehyde (GA) and 1% sodium hypochlorite (SH) on clinically derived poly vinyl siloxane (PVS) impressions. Four clinically derived PVS impressions each were obtained from 10 subjects. One impression from each subject was randomly kept as control (group I), without disinfection. The remaining three impressions were randomly disinfected by immersion in either 2.4% GA (group II), 1% SH (group III), or freshly prepared EOW (group IV). The samples were subjected to microbial culture individually on brain heart infusion (BHI) agar medium. The organisms isolated were confirmed by visual examination and gram staining. Mean colony forming units (CFU) were counted, log 10 reduction obtained and compared. Data were statistically analyzed using one-way ANOVA, followed by multiple comparisons using Tukey-HSD post hoc tests (p < 0.05). Streptococci, Staphylococci, Pseudomonas, Candida, Proteus, Klebsiella, and E. coli were isolated from all impressions including the controls, except those disinfected by EOW. All three disinfectants showed significant reduction in CFU and log 10 reduction values as compared to the controls. EOW showed significantly higher reduction in log 10 values compared to GA and SH, whereas GA and SH showed similar reductions. EOW, GA, and SH showed kill rates of 100%, 99.60%, and 99.82%, respectively. EOW showed significant antimicrobial efficacy as evidenced by reduction in log 10 values when used as an immersion disinfectant for PVS impressions when compared with the results obtained using GA and SH. These results need further investigation. EOW shows high antimicrobial efficacy when used as an immersion disinfectant as compared to GA and SH for clinically derived PVS impressions. © 2016 by the American College of Prosthodontists.

Quantifying the impact cosmetic make-up has on age perception and the first impression projected.

PubMed

Dayan, Steven H; Cho, Katherine; Siracusa, Mary; Gutierrez-Borst, Selika

2015-04-01

First impressions are lasting, consequential and defined as the immediate judgment made of another from zero acquaintance. Multiple studies have reported the benefits of cosmetic make-up. We set out to investigate the psychosocial and aesthetic effects of cosmetic make-up in order to better understand why women wear it. Twenty-seven women were recruited in order to examine the effects of cosmetic make-up on first impressions. The photographs of individual subjects wearing the control cosmetics, their own make-up, and no make-up were randomly assigned to three binders (A, B, and C). Three hundred evaluators participated (100 evaluators per book) and completed a 10-point First Impression Scale for each of the 27 photos in their binder. Statistical analysis of the collected data was conducted in SPSS using two-tailed t-tests to determine the statistical significance of the differences between first impressions of Own Make-up vs No Make-up, No Make-up vs Control Make-up, and Own Makeup vs Control Make-up. There was a significant difference in improvement in all pairings across all 8 categories in the First Impressions questionnaire particularly in perceived age between own make-up, no make-up, control make-up (41, 42, 38; P<0.001). Our study evaluated the first impressions, age perception, self-esteem, and the quality of life impact that cosmetic makeup has on women's appearance and confidence. Subjects wearing cosmetic make-up appeared 4 years younger than those wearing no make-up. And the control cosmetic make-up subjects on average projected a 37% better first impression than subjects wearing no make-up. We objectively quantified and qualified the benefits of applying cosmetic make-up. Make-up can reduce the perceived age, improve the first impression projected and increase the self-esteem of those who apply it.

Effects of Emotional Intelligence on the Impression of Irony Created by the Mismatch between Verbal and Nonverbal Cues.

PubMed

Jacob, Heike; Kreifelts, Benjamin; Nizielski, Sophia; Schütz, Astrid; Wildgruber, Dirk

2016-01-01

Emotional information is conveyed through verbal and nonverbal signals, with nonverbal cues often being considered the decisive factor in the judgment of others' emotional states. The aim of the present study was to examine how verbal and nonverbal cues are integrated by perceivers. More specifically, we tested whether the mismatch between verbal and nonverbal information was perceived as an expression of irony. Moreover, we investigated the effects of emotional intelligence on the impression of irony. The findings revealed that the mismatch between verbal and nonverbal information created the impression of irony. Furthermore, participants higher in emotional intelligence were faster at rating such stimuli as ironic expressions.

Effects of Emotional Intelligence on the Impression of Irony Created by the Mismatch between Verbal and Nonverbal Cues

PubMed Central

Jacob, Heike; Kreifelts, Benjamin; Nizielski, Sophia; Schütz, Astrid; Wildgruber, Dirk

2016-01-01

Emotional information is conveyed through verbal and nonverbal signals, with nonverbal cues often being considered the decisive factor in the judgment of others’ emotional states. The aim of the present study was to examine how verbal and nonverbal cues are integrated by perceivers. More specifically, we tested whether the mismatch between verbal and nonverbal information was perceived as an expression of irony. Moreover, we investigated the effects of emotional intelligence on the impression of irony. The findings revealed that the mismatch between verbal and nonverbal information created the impression of irony. Furthermore, participants higher in emotional intelligence were faster at rating such stimuli as ironic expressions. PMID:27716831

Comparison of Bolton analysis and Little’s irregularity index on laser scanned three-dimensional digital study models with conventional study models

NASA Astrophysics Data System (ADS)

Kurnia, H.; Noerhadi, N. A. I.

2017-08-01

Three-dimensional digital study models were introduced following advances in digital technology. This study was carried out to assess the reliability of digital study models scanned by a laser scanning device newly assembled. The aim of this study was to compare the digital study models and conventional models. Twelve sets of dental impressions were taken from patients with mild-to-moderate crowding. The impressions were taken twice, one with alginate and the other with polyvinylsiloxane. The alginate impressions were made into conventional models, and the polyvinylsiloxane impressions were scanned to produce digital models. The mesiodistal tooth width and Little’s irregularity index (LII) were measured manually with digital calipers on the conventional models and digitally on the digital study models. Bolton analysis was performed on each study models. Each method was carried out twice to check for intra-observer variability. The reproducibility (comparison of the methods) was assessed using independent-sample t-tests. The mesiodistal tooth width between conventional and digital models did not significantly differ (p > 0.05). Independent-sample t-tests did not identify statistically significant differences for Bolton analysis and LII (p = 0.603 for Bolton and p = 0894 for LII). The measurements of the digital study models are as accurate as those of the conventional models.

Stress Strengthens Memory of First Impressions of Others' Positive Personality Traits

PubMed Central

Lass-Hennemann, Johanna; Kuehl, Linn K.; Schulz, André; Oitzl, Melly S.; Schachinger, Hartmut

2011-01-01

Encounters with strangers bear potential for social conflict and stress, but also allow the formation of alliances. First impressions of other people play a critical role in the formation of alliances, since they provide a learned base to infer the other's future social attitude. Stress can facilitate emotional memories but it is unknown whether stress strengthens our memory for newly acquired impressions of other people's personality traits. To answer this question, we subjected 60 students (37 females, 23 males) to an impression-formation task, viewing portraits together with brief positive vs. negative behavior descriptions, followed by a 3-min cold pressor stress test or a non-stressful control procedure. The next day, novel and old portraits were paired with single trait adjectives, the old portraits with a trait adjective matching the previous day's behavior description. After a filler task, portraits were presented again and subjects were asked to recall the trait adjective. Cued recall was higher for old (previously implied) than the novel portraits' trait adjectives, indicating validity of the applied test procedures. Overall, recall rate of implied trait adjectives did not differ between the stress and the control group. However, while the control group showed a better memory performance for others' implied negative personality traits, the stress group showed enhanced recall for others' implied positive personality traits. This result indicates that post-learning stress affects consolidation of first impressions in a valence-specific manner. We propose that the stress-induced strengthening of memory of others' positive traits forms an important cue for the formation of alliances in stressful conditions. PMID:21298099

Accuracy of 3D white light scanning of abutment teeth impressions: evaluation of trueness and precision.

PubMed

Jeon, Jin-Hun; Kim, Hae-Young; Kim, Ji-Hwan; Kim, Woong-Chul

2014-12-01

This study aimed to evaluate the accuracy of digitizing dental impressions of abutment teeth using a white light scanner and to compare the findings among teeth types. To assess precision, impressions of the canine, premolar, and molar prepared to receive all-ceramic crowns were repeatedly scanned to obtain five sets of 3-D data (STL files). Point clouds were compared and error sizes were measured (n=10 per type). Next, to evaluate trueness, impressions of teeth were rotated by 10°-20° and scanned. The obtained data were compared with the first set of data for precision assessment, and the error sizes were measured (n=5 per type). The Kruskal-Wallis test was performed to evaluate precision and trueness among three teeth types, and post-hoc comparisons were performed using the Mann-Whitney U test with Bonferroni correction (α=.05). Precision discrepancies for the canine, premolar, and molar were 3.7 µm, 3.2 µm, and 7.3 µm, respectively, indicating the poorest precision for the molar (P<.001). Trueness discrepancies for teeth types were 6.2 µm, 11.2 µm, and 21.8 µm, respectively, indicating the poorest trueness for the molar (P=.007). In respect to accuracy the molar showed the largest discrepancies compared with the canine and premolar. Digitizing of dental impressions of abutment teeth using a white light scanner was assessed to be a highly accurate method and provided discrepancy values in a clinically acceptable range. Further study is needed to improve digitizing performance of white light scanning in axial wall.

Stress strengthens memory of first impressions of others' positive personality traits.

PubMed

Lass-Hennemann, Johanna; Kuehl, Linn K; Schulz, André; Oitzl, Melly S; Schachinger, Hartmut

2011-01-26

Encounters with strangers bear potential for social conflict and stress, but also allow the formation of alliances. First impressions of other people play a critical role in the formation of alliances, since they provide a learned base to infer the other's future social attitude. Stress can facilitate emotional memories but it is unknown whether stress strengthens our memory for newly acquired impressions of other people's personality traits. To answer this question, we subjected 60 students (37 females, 23 males) to an impression-formation task, viewing portraits together with brief positive vs. negative behavior descriptions, followed by a 3-min cold pressor stress test or a non-stressful control procedure. The next day, novel and old portraits were paired with single trait adjectives, the old portraits with a trait adjective matching the previous day's behavior description. After a filler task, portraits were presented again and subjects were asked to recall the trait adjective. Cued recall was higher for old (previously implied) than the novel portraits' trait adjectives, indicating validity of the applied test procedures. Overall, recall rate of implied trait adjectives did not differ between the stress and the control group. However, while the control group showed a better memory performance for others' implied negative personality traits, the stress group showed enhanced recall for others' implied positive personality traits. This result indicates that post-learning stress affects consolidation of first impressions in a valence-specific manner. We propose that the stress-induced strengthening of memory of others' positive traits forms an important cue for the formation of alliances in stressful conditions.

High Voltage Power Supply Design Guide for Space

NASA Technical Reports Server (NTRS)

Bever, Renate S.; Ruitberg, Arthur P.; Kellenbenz, Carl W.; Irish, Sandra M.

2006-01-01

This book is written for newcomers to the topic of high voltage (HV) in space and is intended to replace an earlier (1970s) out-of-print document. It discusses the designs, problems, and their solutions for HV, mostly direct current, electric power, or bias supplies that are needed for space scientific instruments and devices, including stepping supplies. Output voltages up to 30kV are considered, but only very low output currents, on the order of microamperes. The book gives a brief review of the basic physics of electrical insulation and breakdown problems, especially in gases. It recites details about embedment and coating of the supplies with polymeric resins. Suggestions on HV circuit parts follow. Corona or partial discharge testing on the HV parts and assemblies is discussed both under AC and DC impressed test voltages. Electric field analysis by computer on an HV device is included in considerable detail. Finally, there are many examples given of HV power supplies, complete with some of the circuit diagrams and color photographs of the layouts.

Structural Variation within the Amygdala and Ventromedial Prefrontal Cortex Predicts Memory for Impressions in Older Adults

PubMed Central

Cassidy, Brittany S.; Gutchess, Angela H.

2012-01-01

Research has shown that lesions to regions involved in social and emotional cognition disrupt socioemotional processing and memory. We investigated how structural variation of regions involved in socioemotional memory [ventromedial prefrontal cortex (vmPFC), amygdala], as opposed to a region implicated in explicit memory (hippocampus), affected memory for impressions in young and older adults. Anatomical MRI scans for 15 young and 15 older adults were obtained and reconstructed to gather information about cortical thickness and subcortical volume. Young adults had greater amygdala and hippocampus volumes than old, and thicker left vmPFC than old, although right vmPFC thickness did not differ across the age groups. Participants formed behavior-based impressions and responded to interpersonally meaningful, social but interpersonally irrelevant, or non-social prompts, and completed a memory test. Results showed that greater left amygdala volume predicted enhanced overall memory for impressions in older but not younger adults. Increased right vmPFC thickness in older, but not younger, adults correlated with enhanced memory for impressions formed in the interpersonally meaningful context. Hippocampal volume was not predictive of social memory in young or older adults. These findings demonstrate the importance of structural variation in regions linked to socioemotional processing in the retention of impressions with age, and suggest that the amygdala and vmPFC play integral roles when encoding and retrieving social information. PMID:22973250

Effect of Storage Time of Extended-Pour and Conventional Alginate Impressions on Dimensional Accuracy of Casts

PubMed Central

Rohanian, Ahmad; Ommati Shabestari, Ghasem; Zeighami, Somayeh; Samadi, Mohammad Javad; Shamshiri, Ahmad Reza

2014-01-01

Objectives: Some manufacturers claim to have produced new irreversible hydro-colloids that are able to maintain their dimensional stability during storage. The present study evaluated the effect of storage time on dimensional stability of three alginates: Hydrogum 5, Tropicalgin and Alginoplast. Materials and Methods: In this experimental in-vitro trial, a total of 90 alginate impressions were made from a Dentoform model using Hydrogum 5, Tropicalgin and Alginoplast alginates. The impressions were stored in a sealed plastic bag without a damp paper towel for 0, 24, 48, 72 and 120 hours and then poured with type III dental stone. Cross-arch (facial of 6 to facial of 6 on the opposite side) and antero-posterior (distal of right first molar to the ipsilateral central incisor) measurements were made with a digital caliper on the casts. Data were analyzed by two-way and one-way ANOVA and Tukey’s post-hoc test (P<0.05). Results: Alginate type and the pouring time significantly affected the dimensional stability of alginate impressions (both Ps<0.001). Pouring of Hydrogum 5 impressions can be delayed for up to 120 hours without significant dimensional changes. Alginoplast impressions may be poured after 72 hours, but Tropicalgin should be poured immediately and the storage time should not be more than 24 hours. Conclusion: Immediate pouring of alginate impressions provides the highest accuracy in reproducing the teeth and adjacent tissues; however, this study demonstrated that pouring may be delayed for up to five days using extended-pour (Hydrogum 5) alginates. PMID:25628695

Looking beyond the face: a training to improve perceivers' impressions of people with facial paralysis.

PubMed

Bogart, Kathleen R; Tickle-Degnen, Linda

2015-02-01

Healthcare providers and lay people alike tend to form inaccurate first impressions of people with facial movement disorders such as facial paralysis (FP) because of the natural tendency to base impressions on the face. This study tested the effectiveness of the first interpersonal sensitivity training for FP. Undergraduate participants were randomly assigned to one of two training conditions or an untrained control. Education raised awareness about FP symptoms and experiences and instructed participants to form their impressions based on cues from the body and voice rather than the face. Education+feedback added feedback about the correctness of participants' judgments. Subsequently, participants watched 30s video clips of people with FP and rated their extraversion. Participants' bias and accuracy in the two training conditions did not significantly differ, but they were significantly less biased than controls. Training did not improve the more challenging task of accurately detecting individual differences in extraversion. Educating people improves bias, but not accuracy, of impressions of people with FP. Information from the education condition could be delivered in a pamphlet to those likely to interact with this population such as healthcare providers and educators. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Accuracy of a new ring-opening metathesis elastomeric dental impression material with spray and immersion disinfection.

PubMed

Kronström, Mats H; Johnson, Glen H; Hompesch, Richard W

2010-01-01

A new elastomeric impression material has been formulated with a ring-opening metathesis chemistry. In addition to other properties of clinical significance, the impression accuracy must be confirmed. The purpose of this study was to compare the accuracy of the new elastomeric impression material with vinyl polysiloxane and polyether following both spray and immersion disinfection. Impressions of a modified dentoform with a stainless steel crown preparation in the lower right quadrant were made, and type IV gypsum working casts and dies were formed. Anteroposterior (AP), cross-arch (CA), buccolingual (BL), mesiodistal (MD), occlusogingivobuccal (OGB), and occlusogingivolingual (OGL) dimensions were measured using a microscope. Working cast and die dimensions were compared to those of the master model. The impression materials were a newly formulated, ring-opening metathesis-polymerization impression material (ROMP Cartridge Tray and ROMP Volume Wash), vinyl polysiloxane (VPS, Aquasil Ultra Monophase/LV), and a polyether (PE, Impregum Penta Soft/Permadyne Garant L). Fifteen impressions with each material were made, of which 5 were disinfected by spray for 10 minutes (CaviCide), 5 were disinfected by immersion for 90 minutes (ProCide D), and 5 were not disinfected. There were significant cross-product interactions with a 2-way ANOVA, so a 1-way ANOVA and Dunnett's T3 multiple comparison test were used to compare the dimensional changes of the 3 impression materials, by disinfection status and for each location (alpha=.05). For ROMP, there were no significant differences from the master, for any dimension, when comparing the control and 2 disinfectant conditions. No significant differences were detected among the 3 impression materials for CA, BL, and MD. The working die dimensions of OGB and OGL for VPS with immersion disinfection were significantly shorter than with PE and ROMP (P<.05). Overall, the AP dimension was more accurate than CA, and the BL of working dies was 0.040 mm greater in diameter than MD. The accuracy of gypsum working casts and working dies from the new and 2 existing types of impression material were similar, for both spray and immersion disinfection. Judicious application of a die spacer can compensate for the small differences observed. VPS may require additional laboratory accommodation to compensate for a shorter working die. Copyright 2010 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

30% CPV Module Milestone

NASA Astrophysics Data System (ADS)

Gordon, Robert; Kinsey, Geoff; Nayaak, Adi; Garboushian, Vahan

2010-10-01

Concentrating Photovoltaics has held out the promise of low cost solar electricity for now several decades. Steady progress towards this goal in the 80's and 90's gradually produced more efficient and reliable systems. System efficiency is regarded as the largest factor in lowering the electricity cost and the relatively recent advent of the terrestrial multi-junction solar cell has pressed this race forward dramatically. CPV systems are now exhibiting impressive AC field efficiencies of 25% and more, approximately twice that of the best flat plate systems available today. Amonix inc. has just tested their latest generation multi-junction module design, achieving over 31% DC efficiency at near PVUSA test conditions. Inculcating this design into their next MegaModule is forthcoming, but the expected AC system field efficiency should be significantly higher than current 25% levels.

The effect of prolonged storage and disinfection on the dimensional stability of 5 vinyl polyether silicone impression materials.

PubMed

Nassar, Usama; Flores-Mir, Carlos; Heo, Giseon; Torrealba, Ysidora

2017-06-01

Vinyl polyether silicone (VPES) has a different composition from other elastomeric impression materials as it combines vinyl polysiloxane (VPS) and polyether (PE). Therefore, it is important to study its properties and behavior under different test conditions. This study investigated the dimensional stability of 5 VPES consistencies when stored for up to 2 weeks, with and without using a standard disinfection procedure. 40 discs of each VPES consistency (total 200) were made using a stainless steel die and ring as described by ANSI /ADA specification No. 19. 20 discs of each material were immersed in a 2.5% buffered glutaraldehyde solution for 30 minutes. Dimensional stability measurements were calculated immediately after fabrication and repeated on the same discs after 7 and 14 days of storage. The data was analyzed using two-way ANOVA with a significance level set at α = 0.05. The discs mean contraction was below 0.5% at all test times ranging from 0.200 ± 0.014 to 0.325 ± 0.007. Repeated measures ANOVA showed a statistically significant difference after 2-week storage between the disinfected and non-disinfected groups ( P < .001). Although there was no statistically significant difference between the materials at the time of fabrication, the contraction of the materials increased with storage for 1 and 2 weeks. The dimensional changes of VPES impression discs after disinfection and prolonged storage complied with ANSI/ADA standard. The tested VPES impression materials were dimensionally stable for clinical use after disinfection for 30 minutes in glutaraldehyde and storage for up to 2 weeks.

Advancements in CAD/CAM technology: Options for practical implementation.

PubMed

Alghazzawi, Tariq F

2016-04-01

The purpose of this review is to present a comprehensive review of the current published literature investigating the various methods and techniques for scanning, designing, and fabrication of CAD/CAM generated restorations along with detailing the new classifications of CAD/CAM technology. I performed a review of a PubMed using the following search terms "CAD/CAM, 3D printing, scanner, digital impression, and zirconia". The articles were screened for further relevant investigations. The search was limited to articles written in English, published from 2001 to 2015. In addition, a manual search was also conducted through articles and reference lists retrieved from the electronic search and peer-reviewed journals. CAD/CAM technology has advantages including digital impressions and models, and use of virtual articulators. However, the implementation of this technology is still considered expensive and requires highly trained personnel. Currently, the design software has more applications including complete dentures and removable partial denture frameworks. The accuracy of restoration fabrication can be best attained with 5 axes milling units. The 3D printing technology has been incorporated into dentistry, but does not include ceramics and is limited to polymers. In the future, optical impressions will be replaced with ultrasound impressions using ultrasonic waves, which have the capability to penetrate the gingiva non-invasively without retraction cords and not be affected by fluids. The coming trend for most practitioners will be the use of an acquisition camera attached to a computer with the appropriate software and the capability of forwarding the image to the laboratory. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Budget impact analysis of chronic kidney disease mass screening test in Japan.

PubMed

Kondo, Masahide; Yamagata, Kunihiro; Hoshi, Shu-Ling; Saito, Chie; Asahi, Koichi; Moriyama, Toshiki; Tsuruya, Kazuhiko; Konta, Tsuneo; Fujimoto, Shouichi; Narita, Ichiei; Kimura, Kenjiro; Iseki, Kunitoshi; Watanabe, Tsuyoshi

2014-12-01

Our recently published cost-effectiveness study on chronic kidney disease mass screening test in Japan evaluated the use of dipstick test, serum creatinine (Cr) assay or both in specific health checkup (SHC). Mandating the use of serum Cr assay additionally, or the continuation of current policy mandating dipstick test only was found cost-effective. This study aims to examine the affordability of previously suggested reforms. Budget impact analysis was conducted assuming the economic model would be good for 15 years and applying a population projection. Costs expended by social insurers without discounting were counted as budgets. Annual budget impacts of mass screening compared with do-nothing scenario were calculated as ¥79-¥-1,067 million for dipstick test only, ¥2,505-¥9,235 million for serum Cr assay only and ¥2,517-¥9,251 million for the use of both during a 15-year period. Annual budget impacts associated with the reforms were calculated as ¥975-¥4,129 million for mandating serum Cr assay in addition to the currently used mandatory dipstick test, and ¥963-¥4,113 million for mandating serum Cr assay only and abandoning dipstick test. Estimated values associated with the reform from ¥963-¥4,129 million per year over 15 years are considerable amounts of money under limited resources. The most impressive finding of this study is the decreasing additional expenditures in dipstick test only scenario. This suggests that current policy which mandates dipstick test only would contain medical care expenditure.

Effect of polyvinyl siloxane impression material on the polymerization of composite resin.

PubMed

Chen, Liang; Kleverlaan, Cornelis Johannes; Liang, Kunneng; Yang, Deqin

2017-04-01

Polyvinyl siloxane impression material has been widely used as a lingual matrix for rebuilding missing tooth structure with composite resin. The composite resin is light polymerized in contact with the polyvinyl siloxane impression material. However, polyvinyl siloxane impression material has been shown to interact with other dental materials. The purpose of this study was to assess the effect of polyvinyl siloxane impression materials on the polymerization of composite resins by assessing the Vickers microhardness and degree of conversion of polyvinyl siloxane. The composite resins were light polymerized in contact with 3 polyvinyl siloxane impression materials (Flexitime Easy Putty; President Light Body; Xantopren L Blue) (n=8) and in contact with a matrix strip as the control group (n=8). Vickers microhardness and degree of conversion on contact surfaces were measured to evaluate the polymerization of composite resins. The depth of the effect was assessed by Vickers microhardness on section surfaces and observed with scanning electron microscopy. The results were analyzed by 1-way analysis of variance and the post hoc Tukey honest significant differences test (α=.05). The Vickers microhardness and degree of conversion values on the contact surfaces of the experiment groups were significantly lower than those of the control group (P<.05); the Vickers microhardness values on the section surfaces indicated that there was no significant difference at the same depth of different groups (P>.05). The scanning electron microscope observation showed that an approximately 10-μm deep unpolymerized layer was found in the experimental group. Polyvinyl siloxane impression materials have an inhibitory effect on the polymerization of the composite resins, but just limited to within approximately 10 μm from the surface in contact with the impression material. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Determining localized anode condition to maintain effective corrosion protection.

DOT National Transportation Integrated Search

2010-01-01

Thermal sprayed zinc anodes used for impressed current cathodic protection of reinforced concrete deteriorate over time. : Two different technologies, ultrasound and electrical circuit resistance combined with water permeability, were : investigated ...

Accuracy of two digital implant impression systems based on confocal microscopy with variations in customized software and clinical parameters.

PubMed

Giménez, Beatriz; Pradíes, Guillermo; Martínez-Rus, Francisco; Özcan, Mutlu

2015-01-01

To evaluate the accuracy of two digital impression systems based on the same technology but different postprocessing correction modes of customized software, with consideration of several clinical parameters. A maxillary master model with six implants located in the second molar, second premolar, and lateral incisor positions was fitted with six cylindrical scan bodies. Scan bodies were placed at different angulations or depths apical to the gingiva. Two experienced and two inexperienced operators performed scans with either 3D Progress (MHT) or ZFX Intrascan (Zimmer Dental). Five different distances between implants (scan bodies) were measured, yielding five data points per impression and 100 per impression system. Measurements made with a high-accuracy three-dimensional coordinate measuring machine (CMM) of the master model acted as the true values. The values obtained from the digital impressions were subtracted from the CMM values to identify the deviations. The differences between experienced and inexperienced operators and implant angulation and depth were compared statistically. Experience of the operator, implant angulation, and implant depth were not associated with significant differences in deviation from the true values with both 3D Progress and ZFX Intrascan. Accuracy in the first scanned quadrant was significantly better with 3D Progress, but ZFX Intrascan presented better accuracy in the full arch. Neither of the two systems tested would be suitable for digital impression of multiple-implant prostheses. Because of the errors, further development of both systems is required.

Denial of risk: The effects of positive impression management on risk assessments for psychopathic and nonpsychopathic offenders.

PubMed

Gillard, Nathan D; Rogers, Richard

2015-01-01

Risk assessments for offenders often combine past records with current clinical findings from observations, interviews, and test data. Conclusions based on these risk assessments are highly consequential, sometimes resulting in increased criminal sentences or prolonged hospitalization. Therefore, many offenders are motivated to intentionally minimize risk factors and their negative consequences. Positive impression management (PIM) is especially likely to occur in offenders with high psychopathic traits because goal-directed deception is reflected in several of psychopathy's core traits of the disorder, such as manipulativeness, glibness, and superficial charm. However, this connection appears to be based on the conceptual understanding of psychopathy, and has rarely been examined empirically for either frequency of or success at deception. The current study examined the ability of a jail sample to intentionally minimize risk factors and related criminal attributes using a repeated measures, simulation design. In general, offenders were able to effectively use PIM to lower scores on the HCR-20 and the Self-Appraisal Questionnaire (SAQ), while the Psychological Inventory of Criminal Thinking Styles (PICTS), as a measure of cognitive styles, was more resistant to such minimization. Psychopathic traits, especially high Factor 1 scores (i.e., affective/interpersonal), were associated with greater PIM. Important differences in the willingness and ability to use deception were found based on the (a) mode of administration (i.e., interview vs. self-report) and (b) level of psychopathy as measured by the Psychopathy Checklist - Revised (PCL-R). The important implications of this research are discussed for risk assessment procedures regarding likely areas of deception and its detection. The current research also informs the growing literature on the connection between psychopathic traits and deception. Copyright © 2015 Elsevier Ltd. All rights reserved.

46 CFR 111.05-11 - Hull return.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Hull return. 111.05-11 Section 111.05-11 Shipping COAST... REQUIREMENTS Equipment Ground, Ground Detection, and Grounded Systems § 111.05-11 Hull return. (a) A vessel's hull must not carry current as a conductor except for the following systems: (1) Impressed current...

Factors influencing optical 3D scanning of vinyl polysiloxane impression materials.

PubMed

DeLong, R; Pintado, M R; Ko, C C; Hodges, J S; Douglas, W H

2001-06-01

Future growth in dental practice lies in digital imaging enhancing many chairside procedures and functions. This revolution requires the fast, accurate, and 3D digitizing of clinical records. One such clinical record is the chairside impression. This study investigated how surface angle and surface roughness affect the digitizing of vinyl polysiloxane impression materials. Seventeen vinyl polysiloxane impression materials were digitized with a white light optical digitizing system. Each sample was digitized at 3 different angles: 0 degrees, 22.5 degrees, and 45 degrees, and 2 digitizer camera f-stops. The digitized images were rendered on a computer monitor using custom software developed under NIH/NIDCR grant DE12225. All the 3D images were rotated to the 0 degrees position, cropped using Corel Photo-Paint 8 (Corel Corp, Ottawa, Ontario, Canada), then saved in the TIFF file format. The impression material area that was successfully digitized was calculated as a percentage of the total sample area, using Optimas 5.22 image processing software (Media Cybernetics, LP, Silver Spring, MD). The dependent variable was a Performance Value calculated for each material by averaging the percentage of area that digitized over the 3 angles. New samples with smooth and rough surfaces were made using the 7 impression materials with the largest Performance Values. These samples were tested as before, but with the additional angle of 60 degrees. Silky-Rock die stone (Whip Mix Corp, Louisville, KY) was used as a control. The Performance Values for the 17 impression materials ranged from 0% to 100%. The Performance Values for the 7 best materials were equivalent to the control at f/11 out to a surface angle of 45 degrees; however, only Examix impression material (GC America Inc, Alsip, IL) was equivalent to the control at f/11/\\16. At the 60 degrees surface angle with f/11/\\16, the Performance Values were 0% for all the impression materials, whereas that for the control was 90%. The difference in the Performance Values for the smooth and rough surface textures was 7%, which was not significant. The digitizing performance of vinyl polysiloxane impression materials is highly material and surface angle-dependent and is significantly lower than the die stone control when angles to 60 degrees are included. It is affected to a lesser extent by surface texture. Copyright 2001 by The American College of Prosthodontists.

Accuracy of Digital vs Conventional Implant Impression Approach: A Three-Dimensional Comparative In Vitro Analysis.

PubMed

Basaki, Kinga; Alkumru, Hasan; De Souza, Grace; Finer, Yoav

To assess the three-dimensional (3D) accuracy and clinical acceptability of implant definitive casts fabricated using a digital impression approach and to compare the results with those of a conventional impression method in a partially edentulous condition. A mandibular reference model was fabricated with implants in the first premolar and molar positions to simulate a patient with bilateral posterior edentulism. Ten implant-level impressions per method were made using either an intraoral scanner with scanning abutments for the digital approach or an open-tray technique and polyvinylsiloxane material for the conventional approach. 3D analysis and comparison of implant location on resultant definitive casts were performed using laser scanner and quality control software. The inter-implant distances and interimplant angulations for each implant pair were measured for the reference model and for each definitive cast (n = 20 per group); these measurements were compared to calculate the magnitude of error in 3D for each definitive cast. The influence of implant angulation on definitive cast accuracy was evaluated for both digital and conventional approaches. Statistical analysis was performed using t test (α = .05) for implant position and angulation. Clinical qualitative assessment of accuracy was done via the assessment of the passivity of a master verification stent for each implant pair, and significance was analyzed using chi-square test (α = .05). A 3D error of implant positioning was observed for the two impression techniques vs the reference model, with mean ± standard deviation (SD) error of 116 ± 94 μm and 56 ± 29 μm for the digital and conventional approaches, respectively (P = .01). In contrast, the inter-implant angulation errors were not significantly different between the two techniques (P = .83). Implant angulation did not have a significant influence on definitive cast accuracy within either technique (P = .64). The verification stent demonstrated acceptable passive fit for 11 out of 20 casts and 18 out of 20 casts for the digital and conventional methods, respectively (P = .01). Definitive casts fabricated using the digital impression approach were less accurate than those fabricated from the conventional impression approach for this simulated clinical scenario. A significant number of definitive casts generated by the digital technique did not meet clinically acceptable accuracy for the fabrication of a multiple implant-supported restoration.

40 CFR 264.192 - Design and installation of new tank systems or components.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (e.g., impressed current or sacrificial anodes); and (C) Electrical isolation devices such as... physical damage and excessive stress due to settlement, vibration, expansion, or contraction. [Note: The...

40 CFR 264.192 - Design and installation of new tank systems or components.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (e.g., impressed current or sacrificial anodes); and (C) Electrical isolation devices such as... physical damage and excessive stress due to settlement, vibration, expansion, or contraction. [Note: The...

40 CFR 264.192 - Design and installation of new tank systems or components.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (e.g., impressed current or sacrificial anodes); and (C) Electrical isolation devices such as... physical damage and excessive stress due to settlement, vibration, expansion, or contraction. [Note: The...

40 CFR 264.192 - Design and installation of new tank systems or components.

Code of Federal Regulations, 2014 CFR

2014-07-01

... (e.g., impressed current or sacrificial anodes); and (C) Electrical isolation devices such as... physical damage and excessive stress due to settlement, vibration, expansion, or contraction. [Note: The...

46 CFR 175.400 - Definitions of terms used in this subchapter.

Code of Federal Regulations, 2014 CFR

2014-10-01

... hull from corrosion. It includes, as a minimum, either hull coatings and a cathodic protection (CP) system consisting of sacrificial anodes, or an impressed current CP system. Alternative Hull Examination...

46 CFR 71.50-1 - Definitions relating to hull examinations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... includes, as a minimum, either hull coatings and a cathodic protection (CP) system consisting of sacrificial anodes, or an impressed current CP system. Alternative Hull Examination (AHE) Program means a...

46 CFR 175.400 - Definitions of terms used in this subchapter.

Code of Federal Regulations, 2011 CFR

2011-10-01

... hull from corrosion. It includes, as a minimum, either hull coatings and a cathodic protection (CP) system consisting of sacrificial anodes, or an impressed current CP system. Alternative Hull Examination...

46 CFR 175.400 - Definitions of terms used in this subchapter.

Code of Federal Regulations, 2013 CFR

2013-10-01

... hull from corrosion. It includes, as a minimum, either hull coatings and a cathodic protection (CP) system consisting of sacrificial anodes, or an impressed current CP system. Alternative Hull Examination...

46 CFR 175.400 - Definitions of terms used in this subchapter.

Code of Federal Regulations, 2012 CFR

2012-10-01

... hull from corrosion. It includes, as a minimum, either hull coatings and a cathodic protection (CP) system consisting of sacrificial anodes, or an impressed current CP system. Alternative Hull Examination...

46 CFR 71.50-1 - Definitions relating to hull examinations.

Code of Federal Regulations, 2013 CFR

2013-10-01

... includes, as a minimum, either hull coatings and a cathodic protection (CP) system consisting of sacrificial anodes, or an impressed current CP system. Alternative Hull Examination (AHE) Program means a...

Efficacy of tray adhesives for the adhesion of elastomer rubber impression materials to impression modeling plastics for border molding.

PubMed

Nishigawa, G; Sato, T; Suenaga, K; Minagi, S

1998-02-01

Tray adhesive, which is used for the adhesion of elastomer rubber impression materials to a custom resin tray, lowers the retention of the impression materials to the impression modeling plastics, as some ingredients of tray adhesive make the impression modeling plastic soft and tacky. The efficacy of tray adhesive, which is used for the adhesion of elastomer rubber impression materials to a custom resin tray, on the adhesion between elastomer rubber impression material and impression modeling plastic was investigated. Four silicone rubber impression materials (two addition reaction types and two condensation reaction types), two polysulfide rubber impression materials, and one impression modeling plastic were used in this study. Tensile strength between elastomer rubber impression material and impression modeling plastic with or without the application of tray adhesive was evaluated. Although tray adhesives for both addition reaction type and both condensation reaction type of silicone impression materials and one tray adhesive for polysulfide rubber impression material increased the tensile strength between the impression material and impression modeling plastic, one tray adhesive for polysulfide rubber impression material decreased the tensile strength when sufficient drying time was not applied.

Digital versus conventional implant impressions for partially edentulous arches: An evaluation of accuracy.

PubMed

Marghalani, Amin; Weber, Hans-Peter; Finkelman, Matthew; Kudara, Yukio; El Rafie, Khaled; Papaspyridakos, Panos

2018-04-01

To the authors' knowledge, while accuracy outcomes of the TRIOS scanner have been compared with conventional impressions, no available data are available regarding the accuracy of digital scans with the Omnicam and True Definition scanners versus conventional impressions for partially edentulous arches. The purpose of this in vitro study was to compare the accuracy of digital implant scans using 2 different intraoral scanners (IOSs) with that of conventional impressions for partially edentulous arches. Two partially edentulous mandibular casts with 2 implant analogs with a 30-degree angulation from 2 different implant systems (Replace Select RP; Nobel Biocare and Tissue level RN; Straumann) were used as controls. Sixty digital models were made from these 2 definitive casts in 6 different groups (n=10). Splinted implant-level impression procedures followed by digitization were used to produce the first 2 groups. The next 2 groups were produced by digital scanning with Omnicam. The last 2 groups were produced by digital scanning with the True Definition scanner. Accuracy was evaluated by superimposing the digital files of each test group onto the digital file of the controls with inspection software. The difference in 3-dimensional (3D) deviations (median ±interquartile range) among the 3 impression groups for Nobel Biocare was statistically significant among all groups (P<.001), except for the Omnicam (20 ±4 μm) and True Definition (15 ±6 μm) groups; the median ±interquartile range for the conventional group was 39 ±18 μm. The difference in 3D deviations among the 3 impression groups for Straumann was statistically significant among all groups (P=.003), except for the conventional impression (22 ±5 μm) and True Definition (17 ±5 μm) groups; the median ±interquartile range for the Omnicam group was 26 ±15 μm. The difference in 3D deviations between the 2 implant systems was significant for the Omnicam (P=.011) and conventional (P<.001) impression techniques but not for the True Definition technique (P=.247). Within the limitations of this study, both the impression technique and the implant system affected accuracy. The True Definition technique had the fewest 3D deviations compared with the other 2 techniques; however, the accuracy of all impression techniques was within clinically acceptable levels, and not all differences were statistically significant. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Comparing college students' value-, outcome-, and impression-relevant involvement in health-related issues.

PubMed

Marshall, Heather M; Reinhart, Amber M; Feeley, Thomas H; Tutzauer, Frank; Anker, Ashley

2008-01-01

The purpose of this study was to examine the role of receiver involvement in the context of health communication. Students (N = 277) completed Cho and Boster's (2005) measures of value-, outcome-, and impression-relevant involvement across 6 health behaviors, including cigarette smoking, organ and tissue donation, sunscreen use, alcohol use, sexually transmitted disease testing, and nutrition. Confirmatory factor analyses across all 6 health topics provided evidence of the 3-factor structure conceptualized by Johnson and Eagly (1989) and measured by Cho and Boster (2005). When health behaviors were regressed onto value-, outcome-, and impression-relevant involvement, outcome- and value-involvement, generally speaking, emerged as significant predictors. Results and implications of considering health campaign audience members' levels of involvement are discussed in the domain of preventive medicine.

Two-piece impression procedure for implant-retained orbital prostheses.

PubMed

Ozcelik, Tuncer Burak; Yilmaz, Burak

2012-01-01

Obtaining an accurate impression of facial tissues with undercuts and extraoral implants has always been a challenge for both clinicians and patients. This report describes a three-step, two-piece technique that enables an accurate and comfortable impression of undercut tissues and extraoral implants in an orbital defect. An impression of the basal tissue surface of the defect area was made using a medium-body polyether impression material followed by an impression of the entire face of the patient made with a polyvinyl siloxane (PVS) impression material. First, the PVS impression material was removed; second, the impression posts were removed from the magnets; and third, the polyether impression was removed from the defect. The impression posts were attached to the implant analogs and placed in the negative spaces in the polyether impression. The polyether impression, which carries the implant analogs and impression posts, was placed in the PVS impression through the negative spaces. This technique minimizes trauma to the soft tissues and implants during impression making and also does not require additional materials.

3D and 2D marginal fit of pressed and CAD/CAM lithium disilicate crowns made from digital and conventional impressions.

PubMed

Anadioti, Evanthia; Aquilino, Steven A; Gratton, David G; Holloway, Julie A; Denry, Isabelle; Thomas, Geb W; Qian, Fang

2014-12-01

This in vitro study evaluated the 3D and 2D marginal fit of pressed and computer-aided-designed/computer-aided-manufactured (CAD/CAM) all-ceramic crowns made from digital and conventional impressions. A dentoform tooth (#30) was prepared for an all-ceramic crown (master die). Thirty type IV definitive casts were made from 30 polyvinyl siloxane (PVS) impressions. Thirty resin models were produced from thirty Lava Chairside Oral Scanner impressions. Thirty crowns were pressed in lithium disilicate (IPS e.max Press; 15/impression technique). Thirty crowns were milled from lithium disilicate blocks (IPS e.max CAD; 15/impression technique) using the E4D scanner and milling engine. The master die and the intaglio of the crowns were digitized using a 3D laser coordinate measurement machine with accuracy of ±0.00898 mm. For each specimen a separate data set was created for the Qualify 2012 software. The digital master die and the digital intaglio of each crown were merged using best-fitting alignment. An area above the margin with 0.75 mm occlusal-gingival width circumferentially was defined. The 3D marginal fit of each specimen was an average of all 3D gap values on that area. For the 2D measurements, the marginal gap was measured at two standardized points (on the margin and at 0.75 mm above the margin), from standardized facial-lingual and mesial-distal digitized sections. One-way ANOVA with post hoc Tukey's honestly significant difference and two-way ANOVA tests were used, separately, for statistical analysis of the 3D and 2D marginal data (alpha = 0.05). One-way ANOVA revealed that both 3D and 2D mean marginal gap for group A: PVS impression/IPS e.max Press (0.048 mm ± 0.009 and 0.040 mm ± 0.009) were significantly smaller than those obtained from the other three groups (p < 0.0001), while no significant differences were found among groups B: PVS impression/IPS e.max CAD (0.088 mm ± 0.024 and 0.076 mm ± 0.023), C: digital impression/IPS e.max Press (0.089 mm ± 0.020 and 0.075 mm ± 0.015) and D: digital impression/IPS e.max CAD (0.084 mm ± 0.021 and 0.074 mm ± 0.026). The results of two-way ANOVA revealed a significant interaction between impression techniques and crown fabrication methods for both 3D and 2D measurements. The combination of PVS impression method and press fabrication technique produced the most accurate 3D and 2D marginal fits. © 2014 by the American College of Prosthodontists.

Prediction of residual shear strength of corroded reinforced concrete beams

NASA Astrophysics Data System (ADS)

Imam, Ashhad; Azad, Abul Kalam

2016-09-01

With the aim of providing experimental data on the shear capacity and behavior of corroded reinforced concrete beams that may help in the development of strength prediction models, the test results of 13 corroded and four un-corroded beams are presented. Corrosion damage was induced by accelerated corrosion induction through impressed current. Test results show that loss of shear strength of beams is mostly attributable to two important damage factors namely, the reduction in stirrups area due to corrosion and the corrosion-induced cracking of concrete cover to stirrups. Based on the test data, a method is proposed to predict the residual shear strength of corroded reinforced concrete beams in which residual shear strength is calculated first by using corrosion-reduced steel area alone, and then it is reduced by a proposed reduction factor, which collectively represents all other applicable corrosion damage factors. The method seems to yield results that are in reasonable agreement with the available test data.

Digital Versus Conventional Impressions in Fixed Prosthodontics: A Review.

PubMed

Ahlholm, Pekka; Sipilä, Kirsi; Vallittu, Pekka; Jakonen, Minna; Kotiranta, Ulla

2018-01-01

To conduct a systematic review to evaluate the evidence of possible benefits and accuracy of digital impression techniques vs. conventional impression techniques. Reports of digital impression techniques versus conventional impression techniques were systematically searched for in the following databases: Cochrane Central Register of Controlled Trials, PubMed, and Web of Science. A combination of controlled vocabulary, free-text words, and well-defined inclusion and exclusion criteria guided the search. Digital impression accuracy is at the same level as conventional impression methods in fabrication of crowns and short fixed dental prostheses (FDPs). For fabrication of implant-supported crowns and FDPs, digital impression accuracy is clinically acceptable. In full-arch impressions, conventional impression methods resulted in better accuracy compared to digital impressions. Digital impression techniques are a clinically acceptable alternative to conventional impression methods in fabrication of crowns and short FDPs. For fabrication of implant-supported crowns and FDPs, digital impression systems also result in clinically acceptable fit. Digital impression techniques are faster and can shorten the operation time. Based on this study, the conventional impression technique is still recommended for full-arch impressions. © 2016 by the American College of Prosthodontists.

The effect of prolonged storage and disinfection on the dimensional stability of 5 vinyl polyether silicone impression materials

PubMed Central

Flores-Mir, Carlos; Heo, Giseon; Torrealba, Ysidora

2017-01-01

PURPOSE Vinyl polyether silicone (VPES) has a different composition from other elastomeric impression materials as it combines vinyl polysiloxane (VPS) and polyether (PE). Therefore, it is important to study its properties and behavior under different test conditions. This study investigated the dimensional stability of 5 VPES consistencies when stored for up to 2 weeks, with and without using a standard disinfection procedure. MATERIALS AND METHODS 40 discs of each VPES consistency (total 200) were made using a stainless steel die and ring as described by ANSI /ADA specification No. 19. 20 discs of each material were immersed in a 2.5% buffered glutaraldehyde solution for 30 minutes. Dimensional stability measurements were calculated immediately after fabrication and repeated on the same discs after 7 and 14 days of storage. The data was analyzed using two-way ANOVA with a significance level set at α = 0.05. RESULTS The discs mean contraction was below 0.5% at all test times ranging from 0.200 ± 0.014 to 0.325 ± 0.007. Repeated measures ANOVA showed a statistically significant difference after 2-week storage between the disinfected and non-disinfected groups (P < .001). Although there was no statistically significant difference between the materials at the time of fabrication, the contraction of the materials increased with storage for 1 and 2 weeks. CONCLUSION The dimensional changes of VPES impression discs after disinfection and prolonged storage complied with ANSI/ADA standard. The tested VPES impression materials were dimensionally stable for clinical use after disinfection for 30 minutes in glutaraldehyde and storage for up to 2 weeks. PMID:28680549

Dimensional accuracy of pickup implant impression: an in vitro comparison of novel modular versus standard custom trays.

PubMed

Simeone, Piero; Valentini, Pier Paolo; Pizzoferrato, Roberto; Scudieri, Folco

2011-01-01

The purpose of this in vitro study was to compare the dimensional accuracy of the pickup impression technique using a modular individual tray (MIT) and using a standard individual tray (ST) for multiple internal-connection implants. The roles of both materials and geometric misfits were considered. First, because the MIT relies on the stiffness and elasticity of acrylic resin material, a preliminary investigation of the resin volume contraction during curing and polymerization was done. Then, two sets of specimens were tested to compare the accuracy of the MIT (test group) to that of the ST (control group). The linear and angular displacements of the transfer copings were measured and compared during three different stages of the impression procedure. Experimental measurements were performed with a computerized coordinate measuring machine. The curing dynamic of the acrylic resin was strongly dependent on the physical properties of the acrylic material and the powder/liquid ratio. Specifically, an increase in the powder/liquid ratio accelerated resin polymerization (curing time decreases by 70%) and reduced the final volume contraction by 45%. However, the total shrinkage never exceeded the elastic limits of the material; hence, it did not affect the coping's stability. In the test group, linear errors were reduced by 55% and angular errors were reduced by 65%. Linear and angular displacements of the transfer copings were significantly reduced with the MIT technique, which led to higher dimensional accuracy versus the ST group. The MIT approach, in combination with a thin and uniform amount of acrylic resin in the pickup impression technique, showed no significant permanent distortions in multiple misalignment internal-connection implants compared to the ST technique.

Judging the gender of the inanimate: Benevolent sexism and gender stereotypes guide impressions of physical objects.

PubMed

Meagher, Benjamin R

2017-09-01

Within a given culture, sexist ideologies and stereotypes are largely characterized by their prescriptive expectations for the types of social and behavioural domains men and women occupy. The activities that take place within these respective domains, however, frequently involve designed, physical artefacts. This study reports a pair of studies that test whether sexist schemas are capable of guiding not only impressions of men and women as social groups, but also their impressions of the inanimate objects associated with these groups. In Study 1, benevolent sexism was found to predict a greater willingness to classify physical objects as being either highly feminine or highly masculine, even when these objects had a neutral rating by the sample as a whole. In Study 2, stereotypes consistent with legitimizing ideologies (i.e., competence and warmth) predicted rating associated objects in complementary ways, in terms of greater liking of feminine objects but greater presumed competence needed for using masculine objects. These results demonstrate how sexist beliefs and attitudes are capable of bleeding into people's impressions of the physical world. © 2017 The British Psychological Society.

Consumer facial expression in relation to smoked ham with the use of face reading technology. The methodological aspects and informative value of research results.

PubMed

Kostyra, Eliza; Rambuszek, Michał; Waszkiewicz-Robak, Bożena; Laskowski, Wacław; Blicharski, Tadeusz; Poławska, Ewa

2016-09-01

The study determined the emotional reactions of consumers in relation to hams using face visualization method, which was recorded by FaceReader (FR). The aims of the research were to determine the effect of the ham samples on the type of emotion, to examine more deeply the individual emotional reactions of consumers and to analyse the emotional variability with regard to the temporal measurement of impressions. The research involved testing the effectiveness of measuring emotions in response to the ongoing flavour impression after consumption of smoked hams. It was found that for all of the assessed samples, neutral and negative emotions prevailed as the overall emotions recorded during the assessment of the taste/flavour impression. The range of variability of the overall emotions depended more on the consumer reactions and less on the properties of the assessed product. Consumers expressed various emotions in time and the ham samples evoked different emotional reactions as an effect of duration of the impression. Copyright © 2016 Elsevier Ltd. All rights reserved.

A comparative study of the accuracy between plastic and metal impression transfer copings for implant restorations.

PubMed

Fernandez, Monica A; Paez de Mendoza, Carmen Y; Platt, Jeffrey A; Levon, John A; Hovijitra, Suteera T; Nimmo, Arthur

2013-07-01

A precise transfer of the position and orientation of the antirotational mechanism of an implant to the working cast is particularly important to achieve optimal fit of the final restoration. This study evaluated and compared the accuracy of metal and plastic impression copings for use in a full-arch mandibular edentulous simulation with four implants. Metal and plastic impression transfer copings for two implant systems, Nobel Biocare™ Replace and Straumann SynOcta®, were assessed on a laboratory model to simulate clinical practice. The accuracy of producing stone casts using these plastic and metal impression transfer copings was measured against a standard prosthetic framework consisting of a cast gold bar. A total of 20 casts from the four combinations were obtained. The fit of the framework on the cast was tested by a noncontact surface profilometer, the Proscan 3D 2000 A, using the one-screw test. The effects of implant/system and impression/coping material on gap measurements were analyzed using repeated measures ANOVA. The findings of this in vitro study were as follows: plastic copings demonstrated significantly larger average gaps than metal for Straumann (p = 0.001). Plastic and metal copings were not significantly different for Nobel (p = 0.302). Nobel had significantly larger average gaps than Straumann for metal copings (p = 0.003). Nobel had marginally smaller average gaps than Straumann (p = 0.096) for plastic copings. The system-by-screw location interaction was significant as well (p < 0.001), indicating significant differences among the four screw locations, but the location differences were not the same for the two systems. A rank transformation of the data was necessary due to the nonnormal distribution of the gap measurements. No adjustments were made for multiple comparisons. The metal impression copings were more accurate than plastic copings when using the Straumann system, and there was no difference between metal and plastic copings for the Nobel Replace system. The system-by-screw location was not conclusive, showing no correlation within each system. © 2013 by the American College of Prosthodontists.

Use of a Reflective Ultraviolet Imaging System (RUVIS) on Two-Dimensional Dust Impressions Created with Footwear on Multiple Substrates

NASA Astrophysics Data System (ADS)

Engelson, Brian Aaron

Footwear impression evidence in dust is often difficult to locate in ambient light and is a fragile medium that both collection and enhancement techniques can destroy or distort. The collection of footwear impression evidence always begins with non-destructive photographic techniques; however, current methods are limited to oblique lighting of the impression followed by an attempt to photograph in situ. For the vast majority of footwear impressions, an interactive collection method, and thus a potentially destructive procedure, is subsequently carried out to gather the evidence. Therefore, alternative non-destructive means for the preservation and enhancement of footwear impressions in dust merits further attention. Previous research performed with reflected ultraviolet (UV) photography and reflected ultraviolet imaging systems (RUVIS) has shown that there are additional non-destructive methodologies that can be applied to the search for and documentation of footwear impressions in dust. Unfortunately, these prior studies did not include robust comparisons to traditional oblique white light, instead choosing to focus on different UV wavelengths. This study, however, seeks to evaluate the use of a RUVIS device paired with a 254 nanometer (nm) UV light source to locate 2-D footwear impressions in dust on multiple substrates against standard oblique white light techniques and assess the visibility of the impression and amount of background interference present. The optimal angle of incident UV light for each substrate was also investigated. Finally, this study applied an image enhancement technique in order to evaluate its usefulness when looking at the visibility of a footwear impression and the amount of background interference present for enhanced white light and RUVIS pictures of footwear impressions in dust. A collection of eight different substrate types was gathered for investigation, including vinyl composition tile (VCT), ceramic tile, marble tile, magazine paper, steel sheet metal, vinyl flooring, wood flooring, and carpet. Heel impressions were applied to the various substrates utilizing vacuum collected dust and normal walking pressure. Each substrate was then explored and photographed in ambient fluorescent light, oblique white light at 0°, 15°, 30°, and 0° with the light source below the surface plane of the substrate, and 254 nm UV light at 0°, 15°, 30°, 45°, 60°, 75°, 90° and 0° with the light source below the surface plane of the substrate. All pictures were evaluated for clarity and visible detail of the footwear impression and the amount of background interference present, selecting for the best images within a lighting condition group. Additional intra- and intergroup comparisons were carried out to explore differences created by the various lighting conditions. Enhanced images were then created with the best scored pictures and evaluated for additional modifications in impression visibility and background interference. Photographs of footwear impressions in dust illuminated with ambient fluorescent light proved to be the most difficult conditions under which a footwear impression could be visualized. However, both oblique white light and 254 nm UV light lighting conditions showed improvements in either visualization or background dropout, or both, over ambient light conditions. An assessment of the white light and 254 nm UV light RUVIS images also demonstrated that the best angles for the light source for all substrates were oblique 0 and oblique 0° below the surface plane of the substrate lighting. It was found that white light photographs generally provided higher visibility ratings, while RUVIS 254 nm UV light photographs provided better grades for reducing background interference. Enhanced images of white light conditions provided generally poorer quality and quantity of details, while enhanced RUVIS images seemed to improve upon these areas. The use of a RUVIS to capture photographs of footwear impression evidence in dust was found to be a successful secondary non-destructive technique that can be paired with traditional oblique white light procedures. Additionally, the use of below the surface plane of the substrate lighting techniques were found to improve either visibility or background dropout, or both, over standard 0 oblique lighting, depending on the light source, and should be employed, when applicable. Finally, further investigation into digital photo-editing enhancement techniques for footwear impression evidence in dust is needed.

Accuracy of Gypsum Casts after Different Impression Techniques and Double Pouring

PubMed Central

Silva, Stephania Caroline Rodolfo; Messias, Aion Mangino; Abi-Rached, Filipe de Oliveira; de Souza, Raphael Freitas; Reis, José Maurício dos Santos Nunes

2016-01-01

This study evaluated the accuracy of gypsum casts after different impression techniques and double pouring. Ten patients were selected and for each one it was obtained 5 partial putty/wash impressions with vinyl polysiloxane (VPS) material from teeth #13 to #16 with partial metal stock trays. The following techniques were performed: (1) one-step; two-step relief with: (2) PVC film; (3) slow-speed tungsten carbide bur and scalpel blade, (4) small movements of the tray and (5) without relief—negative control. The impressions were disinfected with 0.5% sodium hypochlorite for 10 minutes and stored during 110 and 230 minutes for the first and second pouring, respectively, with type IV gypsum. Three intra-oral lateral photographs of each patient were taken using a tripod and a customized radiographic positioner. The images were imported into ImageJ software and the total area of the buccal surface from teeth #13 to #16 was measured. A 4.0% coefficient of variance was criterion for using these measurements as Baseline values. The casts were photographed and analyzed using the same standardization for the clinical images. The area (mm2) obtained from the difference between the measurements of each gypsum cast and the Baseline value of the respective patient were calculated and analyzed by repeated-measures two way-ANOVA and Mauchly’s Sphericity test (α = 0.05). No significant effect was observed for Impression technique (P = 0.23), Second pouring (P = 0.99) and their interaction (P = 0.25). The impression techniques and double pouring did not influence the accuracy of the gypsum casts. PMID:27736967

Accuracy of Gypsum Casts after Different Impression Techniques and Double Pouring.

PubMed

Silva, Stephania Caroline Rodolfo; Messias, Aion Mangino; Abi-Rached, Filipe de Oliveira; de Souza, Raphael Freitas; Reis, José Maurício Dos Santos Nunes

2016-01-01

This study evaluated the accuracy of gypsum casts after different impression techniques and double pouring. Ten patients were selected and for each one it was obtained 5 partial putty/wash impressions with vinyl polysiloxane (VPS) material from teeth #13 to #16 with partial metal stock trays. The following techniques were performed: (1) one-step; two-step relief with: (2) PVC film; (3) slow-speed tungsten carbide bur and scalpel blade, (4) small movements of the tray and (5) without relief-negative control. The impressions were disinfected with 0.5% sodium hypochlorite for 10 minutes and stored during 110 and 230 minutes for the first and second pouring, respectively, with type IV gypsum. Three intra-oral lateral photographs of each patient were taken using a tripod and a customized radiographic positioner. The images were imported into ImageJ software and the total area of the buccal surface from teeth #13 to #16 was measured. A 4.0% coefficient of variance was criterion for using these measurements as Baseline values. The casts were photographed and analyzed using the same standardization for the clinical images. The area (mm2) obtained from the difference between the measurements of each gypsum cast and the Baseline value of the respective patient were calculated and analyzed by repeated-measures two way-ANOVA and Mauchly's Sphericity test (α = 0.05). No significant effect was observed for Impression technique (P = 0.23), Second pouring (P = 0.99) and their interaction (P = 0.25). The impression techniques and double pouring did not influence the accuracy of the gypsum casts.

Accuracy of Implant Position Transfer and Surface Detail Reproduction with Different Impression Materials and Techniques

PubMed Central

Alikhasi, Marzieh; Siadat, Hakimeh; Kharazifard, Mohammad Javad

2015-01-01

Objectives: The purpose of this study was to compare the accuracy of implant position transfer and surface detail reproduction using two impression techniques and materials. Materials and Methods: A metal model with two implants and three grooves of 0.25, 0.50 and 0.75 mm in depth on the flat superior surface of a die was fabricated. Ten regular-body polyether (PE) and 10 regular-body polyvinyl siloxane (PVS) impressions with square and conical transfer copings using open tray and closed tray techniques were made for each group. Impressions were poured with type IV stone, and linear and angular displacements of the replica heads were evaluated using a coordinate measuring machine (CMM). Also, accurate reproduction of the grooves was evaluated by a video measuring machine (VMM). These measurements were compared with the measurements calculated on the reference model that served as control, and the data were analyzed with two-way ANOVA and t-test at P= 0.05. Results: There was less linear displacement for PVS and less angular displacement for PE in closed-tray technique, and less linear displacement for PE in open tray technique (P<0.001). Also, the open tray technique showed less angular displacement with the use of PVS impression material. Detail reproduction accuracy was the same in all the groups (P>0.05). Conclusion: The open tray technique was more accurate using PE, and also both closed tray and open tray techniques had acceptable results with the use of PVS. The choice of impression material and technique made no significant difference in surface detail reproduction. PMID:27252761

Effect of two types of latex gloves and surfactants on polymerization inhibition of three polyvinylsiloxane impression materials.

PubMed

Peregrina, Alejandro; Land, Martin F; Feil, Phillip; Price, Connie

2003-09-01

Polymerization inhibition of polyvinylsiloxane impression materials has been reported when in sustained contact with some types of latex gloves. This study examined the polymerization inhibition of 3 polyvinylsiloxane impression materials placed in contact with surfaces subjected to prior contact with gloves or commonly used surfactants. A 2 x 3 x 4 x 2 design was used (n = 20), with 2 types of gloves (powdered and unpowdered), 3 types of polyvinylsiloxane impression materials (Aquasil, Extrude, and Affinis), 4 surfactant conditions (water, soap/water-rinse, alcohol, and unexposed), and 2 ambient temperatures of 22 degrees C and 36 degrees C. After glove exposure to surfactants, a glass surface was subjected to rubbing contact with the treated glove for a standardized time. After drying, automixed polyvinylsiloxane impression materials were dispensed onto the treated surface. Specimens were removed and evaluated for polymerization inhibition at the manufacturer's recommended polymerization time (36 degrees C), or after 15 minutes at 22 degrees C. Specimens were rated as polymerized, or as inhibited if any polyvinylsiloxane residue remained on the slab. A chi-square analysis was used to evaluate the results (alpha=.05). Setting inhibition was found only with one of the polyvinylsiloxane materials when alcohol was used as a surfactant. At 22 degrees C, the inhibition rate ranged from 95% to 100% for both glove types; at 36 degrees C inhibition ranged from 40% (unpowdered gloves) to 75% (powdered gloves), respectively. Under these in vitro conditions, glove exposure to alcohol resulted in polymerization inhibition of 1 of 3 tested polyvinylsiloxane impression materials (Extrude).

Test-Tampering Found Rampant in Atlanta System

ERIC Educational Resources Information Center

Samuels, Christina A.

2011-01-01

The author reports on a state investigation into Atlanta's impressive gains on state tests which finds that test-tampering was rampant in the much-praised school system. The report unveiled by the Georgia governor's office states that Atlanta teachers and principals for years methodically altered answer sheets for students taking state tests,…

In situ fabrication of nickel aluminum-layered double hydroxide nanosheets/hollow carbon nanofibers composite as a novel electrode material for supercapacitors

NASA Astrophysics Data System (ADS)

He, Fang; Hu, Zhibiao; Liu, Kaiyu; Zhang, Shuirong; Liu, Hongtao; Sang, Shangbin

2014-12-01

This paper introduces a new design route to fabricate nickel aluminum-layered double hydroxide (NiAl-LDH) nanosheets/hollow carbon nanofibers (CNFs) composite through an in situ growth method. The NiAl-LDH thin layers which grow on hollow carbon nanofibers have an average thickness of 13.6 nm. The galvanostatic charge-discharge test of the NiAl-LDH/CNFs composite yields an impressive specific capacitance of 1613 F g-1 at 1 A g-1 in 6 M KOH solution, the composite shows a remarkable specific capacitance of 1110 F g-1 even at a high current density of 10 A g-1. Furthermore, the composite remains a specific capacitance of 1406 F g-1 after 1000 cycles at 2 A g-1, indicating the composite has excellent high-current capacitive behavior and good cycle stability in compared to pristine NiAl-LDH.

Interfacial chemistry of zinc anodes for reinforced concrete structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Covino, B.S. Jr.; Bullard, S.J.; Cramer, S.D.

1997-12-01

Thermally-sprayed zinc anodes are used in both galvanic and impressed current cathodic protection systems for reinforced concrete structures. The Albany Research Center, in collaboration with the Oregon Department of Transportation, has been studying the effect of electrochemical aging on the bond strength of zinc anodes for bridge cathodic protection systems. Changes in anode bond strength and other anode properties can be explained by the chemistry of the zinc-concrete interface. The chemistry of the zinc-concrete interface in laboratory electrochemical aging studies is compared with that of several bridges with thermal-sprayed zinc anodes and which have been in service for 5 tomore » 10 years using both galvanic and impressed current cathodic protection systems. The bridges are the Cape Creek Bridge on the Oregon coast and the East Camino Undercrossing near Placerville, CA. Also reported are interfacial chemistry results for galvanized steel rebar from the 48 year old Longbird Bridge in Bermuda.« less

To Fake or Not to Fake: Antecedents to Interview Faking, Warning Instructions, and Its Impact on Applicant Reactions

PubMed Central

Law, Stephanie J.; Bourdage, Joshua; O’Neill, Thomas A.

2016-01-01

In the present study, we examined the antecedents and processes that impact job interviewees’ decisions to engage in deceptive impression management (i.e., interview faking). Willingness and capacity to engage in faking were found to be the processes underlying the decision to use deceptive impression management in the interview. We also examined a personality antecedent to this behavior, Honesty-Humility, which was negatively related to the use of deceptive impression management through increased willingness to engage in these behaviors. We also tested a possible intervention to reduce IM. In particular, we found that warnings against faking – specifically, an identification warning - reduced both the perceived capacity to engage in interview faking, and subsequent use of several faking behaviors. Moreover, this warning reduced faking without adversely impacting applicant reactions. PMID:27895609

The importance of a two-step impression procedure for complete denture fabrication: a systematic review of the literature.

PubMed

Regis, R R; Alves, C C S; Rocha, S S M; Negreiros, W A; Freitas-Pontes, K M

2016-10-01

The literature has questioned the real need for some clinical and laboratory procedures considered essential for achieving better results for complete denture fabrication. The aim of this study was to review the current literature concerning the relevance of a two-step impression procedure to achieve better clinical results in fabricating conventional complete dentures. Through an electronic search strategy of the PubMed/MEDLINE database, randomised controlled clinical trials which compared complete denture fabrication in adults in which one or two steps of impressions occurred were identified. The selections were made by three independent reviewers. Among the 540 titles initially identified, four studies (seven published papers) reporting on 257 patients evaluating aspects such as oral health-related quality of life, patient satisfaction with dentures in use, masticatory performance and chewing ability, denture quality, direct and indirect costs were considered eligible. The quality of included studies was assessed according to the Cochrane guidelines. The clinical studies considered for this review suggest that a two-step impression procedure may not be mandatory for the success of conventional complete denture fabrication regarding a variety of clinical aspects of denture quality and patients' perceptions of the treatment. © 2016 John Wiley & Sons Ltd.

Cardiac vagal flexibility and accurate personality impressions: Examining a physiological correlate of the good judge.

PubMed

Human, Lauren J; Mendes, Wendy Berry

2018-02-23

Research has long sought to identify which individuals are best at accurately perceiving others' personalities or are good judges, yet consistent predictors of this ability have been difficult to find. In the current studies, we revisit this question by examining a novel physiological correlate of social sensitivity, cardiac vagal flexibility, which reflects dynamic modulation of cardiac vagal control. We examined whether greater cardiac vagal flexibility was associated with forming more accurate personality impressions, defined as viewing targets more in line with their distinctive self-reported profile of traits, in two studies, including a thin-slice video perceptions study (N = 109) and a dyadic interaction study (N = 175). Across studies, we found that individuals higher in vagal flexibility formed significantly more accurate first impressions of others' more observable personality traits (e.g., extraversion, creativity, warmth). These associations held while including a range of relevant covariates, including cardiac vagal tone, sympathetic activation, and gender. In sum, social sensitivity as indexed by cardiac vagal flexibility is linked to forming more accurate impressions of others' observable traits, shedding light on a characteristic that may help to identify the elusive good judge and providing insight into its neurobiological underpinnings. © 2018 Wiley Periodicals, Inc.

Comparison of digital scanning and polyvinyl siloxane impression techniques by dental students: instructional efficiency and attitudes towards technology.

PubMed

Marti, A M; Harris, B T; Metz, M J; Morton, D; Scarfe, W C; Metz, C J; Lin, W-S

2017-08-01

With increasing use of digital scanning with restorative procedures in the dental office, it becomes necessary that educational institutions adopt instructional methodology for introducing this technology together with conventional impression techniques. To compare the time differences between instructing dental students on digital scanning (DS) (LAVA C.O.S. digital impression system) and a conventional impression technique (CI) (polyvinyl siloxane), and to compare students' attitudes and beliefs towards both techniques. Volunteer sophomore dental students (n = 25) with no prior experience in clinical impressions were recruited and IRB consent obtained. Participants responded to a pre-and post-exposure questionnaire. Participants were instructed on the use of both DS and CI for a single tooth full coverage crown restoration using a consecutive sequence of video lecture, investigator-led demonstration and independent impression exercise. The time necessary for each step (minutes) was recorded. Statistical significance was calculated using dependent t-tests (time measurements) and 2-sample Mann-Whitney (questionnaire responses). The time spent teaching students was greater for DS than CI for video lecture (15.95 and 10.07 min, P = 0.0000), demonstration time (9.06 and 4.70 min, P = 0.0000) and impression time (18.17 and 8.59 min, P = 0.0000). Prior to the instruction and practice, students considered themselves more familiar with CI (3.96) than DS (1.96) (P = 0.0000). After the instruction and practice, participants reported CI technique proved significantly easier than expected (pre-instruction: 3.52 and post-instruction: 4.08, P = 0.002). However, overall participants' perception of ease of use for DS was not influenced by this instruction and practice experience (pre-instruction: 3.84 and post-instruction: 3.56, P = 0.106). Despite the results, 96% of participants expressed an expectation that DS will become their predominant impression technique during their careers. Dental students with no clinical experience have high expectations for digital scanning, and despite their initial difficulty, expect it to become their primary impression technique during their professional futures. The instructional time necessary for introducing DS into the curriculum is significantly greater than CI in both classroom (lecture) and clinical simulation settings (investigator-led demonstration). © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Late Carboniferous paleoichnology reveals the oldest full-body impression of a flying insect.

PubMed

Knecht, Richard J; Engel, Michael S; Benner, Jacob S

2011-04-19

Insects were the first animals to evolve powered flight and did so perhaps 90 million years before the first flight among vertebrates. However, the earliest fossil record of flying insect lineages (Pterygota) is poor, with scant indirect evidence from the Devonian and a nearly complete dearth of material from the Early Carboniferous. By the Late Carboniferous a diversity of flying lineages is known, mostly from isolated wings but without true insights into the paleoethology of these taxa. Here, we report evidence of a full-body impression of a flying insect from the Late Carboniferous Wamsutta Formation of Massachusetts, representing the oldest trace fossil of Pterygota. Through ethological and morphological analysis, the trace fossil provides evidence that its maker was a flying insect and probably was representative of a stem-group lineage of mayflies. The nature of this current full-body impression somewhat blurs distinctions between the systematics of traces and trace makers, thus adding to the debate surrounding ichnotaxonomy for traces with well-associated trace makers.

[A new system of testing visual performance based on the cylindrical lens screen].

PubMed

Doege, E; Krause, O

1983-09-01

Using a special microoptical screen as a test-picture coating, a method for testing binocular function was developed. It offers the advantage of providing a separate visual impression to each eye from a diagnostic picture without using any device in front of the eyes. The person tested is unaware of this procedure, of which the diagnostic plate gives no hint. In addition to a description of its numerous uses and diagnostic possibilities, fusion pictures suitable for screening tests are described: Each eye is offered a separate impression with a completely different content. If fusion occurs correctly, a third motif with an entirely new meaning emerges. Several years of experience with this effective system (naked-eye tests) resulted in aids which are listed in the final section of the paper: exercise aids used for preparing the persons tested (especially infants) in the waiting room, recognition aids for the examination, and a partially kinetic picture for rapid, simple and very convincing representation of adjusting movements and of the squint position in cases of concomitant squint.

Time efficiency, difficulty, and operator's preference comparing digital and conventional implant impressions: a randomized controlled trial.

PubMed

Joda, Tim; Lenherr, Patrik; Dedem, Philipp; Kovaltschuk, Irina; Bragger, Urs; Zitzmann, Nicola U

2017-10-01

The aim of this randomized controlled trial was to analyze implant impression techniques applying intraoral scanning (IOS) and the conventional method according to time efficiency, difficulty, and operator's preference. One hundred participants (n = 100) with diverse levels of dental experience were included and randomly assigned to Group A performing digital scanning (TRIOS Pod) first or Group B conducting conventional impression (open tray with elastomer) first, while the second method was performed consecutively. A customized maxillary model with a bone-level-type implant in the right canine position (FDI-position 13) was mounted on a phantom training unit realizing a standardized situation for all participants. Outcome parameter was time efficiency, and potential influence of clinical experience, operator's perception of level of difficulty, applicability of each method, and subjective preferences were analyzed with Wilcoxon -Mann-Whitney and Kruskal-Wallis tests. Mean total work time varied between 5.01 ± 1.56 min (students) and 4.53 ± 1.34 min (dentists) for IOS, and between 12.03 ± 2.00 min (students) and 10.09 ± 1.15 min (dentists) for conventional impressions with significant differences between the two methods. Neither assignment to Group A or B, nor gender nor number of impression-taking procedures did influence working time. Difficulty and applicability of IOS was perceived more favorable compared to conventional impressions, and effectiveness of IOS was rated better by the majority of students (88%) and dentists (64%). While 76% of the students preferred IOS, 48% of the dentists were favoring conventional impressions, and 26% each IOS and either technique. For single-implant sites, the quadrant-like intraoral scanning (IOS) was more time efficient than the conventional full-arch impression technique in a phantom head simulating standardized optimal conditions. A high level of acceptance for IOS was observed among students and dentists. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Can physician examiners overcome their first impression when examinee performance changes?

PubMed

Wood, Timothy J; Pugh, Debra; Touchie, Claire; Chan, James; Humphrey-Murto, Susan

2018-03-20

There is an increasing focus on factors that influence the variability of rater-based judgments. First impressions are one such factor. First impressions are judgments about people that are made quickly and are based on little information. Under some circumstances, these judgments can be predictive of subsequent decisions. A concern for both examinees and test administrators is whether the relationship remains stable when the performance of the examinee changes. That is, once a first impression is formed, to what degree will an examiner be willing to modify it? The purpose of this study is to determine the degree that first impressions influence final ratings when the performance of examinees changes within the context of an objective structured clinical examination (OSCE). Physician examiners (n = 29) viewed seven videos of examinees (i.e., actors) performing a physical exam on a single OSCE station. They rated the examinees' clinical abilities on a six-point global rating scale after 60 s (first impression or FIGR). They then observed the examinee for the remainder of the station and provided a final global rating (GRS). For three of the videos, the examinees' performance remained consistent throughout the videos. For two videos, examinee performance changed from initially strong to weak and for two videos, performance changed from initially weak to strong. The mean FIGR rating for the Consistent condition (M = 4.80) and the Strong to Weak condition (M = 4.87) were higher compared to their respective GRS ratings (M = 3.93, M = 2.73) with a greater decline for the Strong to Weak condition. The mean FIGR rating for the Weak to Strong condition was lower (3.60) than the corresponding mean GRS (4.81). This pattern of findings suggests that raters were willing to change their judgments based on examinee performance. Future work should explore the impact of making a first impression judgment explicit versus implicit and the role of context on the relationship between a first impression and a subsequent judgment.

Turning Noise into Signal: Utilizing Impressed Pipeline Currents for EM Exploration

NASA Astrophysics Data System (ADS)

Lindau, Tobias; Becken, Michael

2017-04-01

Impressed Current Cathodic Protection (ICCP) systems are extensively used for the protection of central Europe's dense network of oil-, gas- and water pipelines against destruction by electrochemical corrosion. While ICCP systems usually provide protection by injecting a DC current into the pipeline, mandatory pipeline integrity surveys demand a periodical switching of the current. Consequently, the resulting time varying pipe currents induce secondary electric- and magnetic fields in the surrounding earth. While these fields are usually considered to be unwanted cultural noise in electromagnetic exploration, this work aims at utilizing the fields generated by the ICCP system for determining the electrical resistivity of the subsurface. The fundamental period of the switching cycles typically amounts to 15 seconds in Germany and thereby roughly corresponds to periods used in controlled source EM applications (CSEM). For detailed studies we chose an approximately 30km long pipeline segment near Herford, Germany as a test site. The segment is located close to the southern margin of the Lower Saxony Basin (LSB) and part of a larger gas pipeline composed of multiple segments. The current injected into the pipeline segment originates in a rectified 50Hz AC signal which is periodically switched on and off. In contrast to the usual dipole sources used in CSEM surveys, the current distribution along the pipeline is unknown and expected to be non-uniform due to coating defects that cause current to leak into the surrounding soil. However, an accurate current distribution is needed to model the fields generated by the pipeline source. We measured the magnetic fields at several locations above the pipeline and used Biot-Savarts-Law to estimate the currents decay function. The resulting frequency dependent current distribution shows a current decay away from the injection point as well as a frequency dependent phase shift which is increasing with distance from the injection point. Electric field data were recorded at 45 stations located in an area of about 60 square kilometers in the vicinity to the pipeline. Additionally, the injected source current was recorded directly at the injection point. Transfer functions between the local electric fields and the injected source current are estimated for frequencies ranging from 0.03Hz to 15Hz using robust time series processing techniques. The resulting transfer functions are inverted for a 3D conductivity model of the subsurface using an elaborate pipeline model. We interpret the model with regards to the local geologic setting, demonstrating the methods capabilities to image the subsurface.

Conventional Vs Digital Impressions: Acceptability, Treatment Comfort and Stress Among Young Orthodontic Patients.

PubMed

Mangano, Alessandro; Beretta, Matteo; Luongo, Giuseppe; Mangano, Carlo; Mangano, Francesco

2018-01-01

The objective of the present study was to compare patients' acceptability, comfort and stress with conventional and digital impressions. Thirty young orthodontic patients (15 males and 15 females) who had no previous experience of impressions were enrolled in this study. Conventional impressions for orthodontic study models of the dental arches were taken using an alginate impression material (Hydrogum ® , Zhermack Spa, Badia Polesine, Rovigo, Italy). Fifteen days later, digital impressions of both arches were acquired using an intraoral scanner (CS3600 ® , Carestream Dental, Rochester, NY, USA). Immediately after impression taking, patients' acceptability, comfort and stress were measured using two questionnaires and the State anxiety scale. Data showed no difference in terms of anxiety and stress; however, patients preferred the use of digital impressions systems instead of conventional impression techniques. Alginate impressions resulted as fast as digital impressions. Digital impressions resulted the most accepted and comfortable impression technique in young orthodontic patients, when compared to conventional techniques.

Restoration of the Donor Face After Facial Allotransplantation

PubMed Central

Grant, Gerald T.; Liacouras, Peter; Santiago, Gabriel F.; Garcia, Juan R.; Al Rakan, Mohammed; Murphy, Ryan; Armand, Mehran; Gordon, Chad R.

2014-01-01

Introduction Current protocols for facial transplantation include the mandatory fabrication of an alloplastic “mask” to restore the congruency of the donor site in the setting of “open casket” burial. However, there is currently a paucity of literature describing the current state-of-the-art and available options. Methods During this study, we identified that most of donor masks are fabricated using conventional methods of impression, molds, silicone, and/or acrylic application by an experienced anaplastologist or maxillofacial prosthetics technician. However, with the recent introduction of several enhanced computer-assisted technologies, our facial transplant team hypothesized that there were areas for improvement with respect to cost and preparation time. Results The use of digital imaging for virtual surgical manipulation, computer-assisted planning, and prefabricated surgical cutting guides—in the setting of facial transplantation—provided us a novel opportunity for digital design and fabrication of a donor mask. The results shown here demonstrate an acceptable appearance for “open-casket” burial while maintaining donor identity after facial organ recovery. Conclusions Several newer techniques for fabrication of facial transplant donor masks exist currently and are described within the article. These encompass digital impression, digital design, and additive manufacturing technology. PMID:24835867

Precision of fit between implant impression coping and implant replica pairs for three implant systems.

PubMed

Nicoll, Roxanna J; Sun, Albert; Haney, Stephan; Turkyilmaz, Ilser

2013-01-01

The fabrication of an accurately fitting implant-supported fixed prosthesis requires multiple steps, the first of which is assembling the impression coping on the implant. An imprecise fit of the impression coping on the implant will cause errors that will be magnified in subsequent steps of prosthesis fabrication. The purpose of this study was to characterize the 3-dimensional (3D) precision of fit between impression coping and implant replica pairs for 3 implant systems. The selected implant systems represent the 3 main joint types used in implant dentistry: external hexagonal, internal trilobe, and internal conical. Ten impression copings and 10 implant replicas from each of the 3 systems, B (Brånemark System), R (NobelReplace Select), and A (NobelActive) were paired. A standardized aluminum test body was luted to each impression coping, and the corresponding implant replica was embedded in a stone base. A coordinate measuring machine was used to quantify the maximum range of displacement in a vertical direction as a function of the tightening force applied to the guide pin. Maximum angular displacement in a horizontal plane was measured as a function of manual clockwise or counterclockwise rotation. Vertical and rotational positioning was analyzed by using 1-way analysis of variance (ANOVA). The Fisher protected least significant difference (PLSD) multiple comparisons test of the means was applied when the F-test in the ANOVA was significant (α=.05). The mean and standard deviation for change in the vertical positioning of impression copings was 4.3 ±2.1 μm for implant system B, 2.8 ±4.2 μm for implant system R, and 20.6 ±8.8 μm for implant system A. The mean and standard deviation for rotational positioning was 3.21 ±0.98 degrees for system B, 2.58 ±1.03 degrees for system R, and 5.30 ±0.79 degrees for system A. The P-value for vertical positioning between groups A and B and between groups A and R was <.001. No significant differences were found for vertical positioning between groups B and R. The P-value for rotational positioning between groups A and B and between groups A and R was <.001. No significant differences were found for rotational positioning between groups B and R. The results of the study confirmed that implant systems differ in precision of fit. Vertical precision between paired implant components is a function of joint type and the tightening force applied to the guide pin. The magnitude of vertical displacement with applied torque is greater for conical connections than for butt joint connections. The rotational freedom between paired components is unique to the implant system and is presumably related to the machining tolerances specified by the manufacturer. Copyright © 2013 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

A Lasting Impression: A Pedagogical Perspective on Youth Fitness Testing

ERIC Educational Resources Information Center

Silverman, Stephen; Keating, Xiaofen Deng; Phillips, Sharon R.

2008-01-01

This article addresses ways in which fitness tests can be used positively in physical education. We take the position throughout the article that fitness tests should be used as formative evaluation to further educational goals. We begin by discussing the different ways in which adults and children use fitness tests. The next section, the heart of…

Driving CAR T-cells forward.

PubMed

Jackson, Hollie J; Rafiq, Sarwish; Brentjens, Renier J

2016-06-01

The engineered expression of chimeric antigen receptors (CARs) on the surface of T cells enables the redirection of T-cell specificity. Early clinical trials using CAR T cells for the treatment of patients with cancer showed modest results, but the impressive outcomes of several trials of CD19-targeted CAR T cells in the treatment of patients with B-cell malignancies have generated an increased enthusiasm for this approach. Important lessons have been derived from clinical trials of CD19-specific CAR T cells, and ongoing clinical trials are testing CAR designs directed at novel targets involved in haematological and solid malignancies. In this Review, we discuss these trials and present strategies that can increase the antitumour efficacy and safety of CAR T-cell therapy. Given the fast-moving nature of this field, we only discuss studies with direct translational application currently or soon-to-be tested in the clinical setting.

Driving CAR T-cells forward

PubMed Central

Jackson, Hollie J.; Rafiq, Sarwish; Brentjens, Renier J.

2017-01-01

The engineered expression of chimeric antigen receptors (CARs) on the surface of T cells enables the redirection of T-cell specificity. Early clinical trials using CAR T cells for the treatment of patients with cancer showed modest results, but the impressive outcomes of several trials of CD19-targeted CAR T cells in the treatment of patients with B-cell malignancies have generated an increased enthusiasm for this approach. Important lessons have been derived from clinical trials of CD19-specific CAR T cells, and ongoing clinical trials are testing CAR designs directed at novel targets involved in haematological and solid malignancies. In this Review, we discuss these trials and present strategies that can increase the antitumour efficacy and safety of CAR T-cell therapy. Given the fast-moving nature of this field, we only discuss studies with direct translational application currently or soon-to-be tested in the clinical setting. PMID:27000958

Reliable quantum certification of photonic state preparations

PubMed Central

Aolita, Leandro; Gogolin, Christian; Kliesch, Martin; Eisert, Jens

2015-01-01

Quantum technologies promise a variety of exciting applications. Even though impressive progress has been achieved recently, a major bottleneck currently is the lack of practical certification techniques. The challenge consists of ensuring that classically intractable quantum devices perform as expected. Here we present an experimentally friendly and reliable certification tool for photonic quantum technologies: an efficient certification test for experimental preparations of multimode pure Gaussian states, pure non-Gaussian states generated by linear-optical circuits with Fock-basis states of constant boson number as inputs, and pure states generated from the latter class by post-selecting with Fock-basis measurements on ancillary modes. Only classical computing capabilities and homodyne or hetorodyne detection are required. Minimal assumptions are made on the noise or experimental capabilities of the preparation. The method constitutes a step forward in many-body quantum certification, which is ultimately about testing quantum mechanics at large scales. PMID:26577800

Soil chemical sensor and precision agricultural chemical delivery system and method

DOEpatents

Colburn, Jr., John W.

1991-01-01

A real time soil chemical sensor and precision agricultural chemical delivery system includes a plurality of ground-engaging tools in association with individual soil sensors which measure soil chemical levels. The system includes the addition of a solvent which rapidly saturates the soil/tool interface to form a conductive solution of chemicals leached from the soil. A multivalent electrode, positioned within a multivalent frame of the ground-engaging tool, applies a voltage or impresses a current between the electrode and the tool frame. A real-time soil chemical sensor and controller senses the electrochemical reaction resulting from the application of the voltage or current to the leachate, measures it by resistivity methods, and compares it against pre-set resistivity levels for substances leached by the solvent. Still greater precision is obtained by calibrating for the secondary current impressed through solvent-less soil. The appropriate concentration is then found and the servo-controlled delivery system applies the appropriate amount of fertilizer or agricultural chemicals substantially in the location from which the soil measurement was taken.

Soil chemical sensor and precision agricultural chemical delivery system and method

DOEpatents

Colburn, J.W. Jr.

1991-07-23

A real time soil chemical sensor and precision agricultural chemical delivery system includes a plurality of ground-engaging tools in association with individual soil sensors which measure soil chemical levels. The system includes the addition of a solvent which rapidly saturates the soil/tool interface to form a conductive solution of chemicals leached from the soil. A multivalent electrode, positioned within a multivalent frame of the ground-engaging tool, applies a voltage or impresses a current between the electrode and the tool frame. A real-time soil chemical sensor and controller senses the electrochemical reaction resulting from the application of the voltage or current to the leachate, measures it by resistivity methods, and compares it against pre-set resistivity levels for substances leached by the solvent. Still greater precision is obtained by calibrating for the secondary current impressed through solvent-less soil. The appropriate concentration is then found and the servo-controlled delivery system applies the appropriate amount of fertilizer or agricultural chemicals substantially in the location from which the soil measurement was taken. 5 figures.

Precision and Accuracy of a Digital Impression Scanner in Full-Arch Implant Rehabilitation.

PubMed

Pesce, Paolo; Pera, Francesco; Setti, Paolo; Menini, Maria

To evaluate the accuracy and precision of a digital scanner used to scan four implants positioned according to an immediate loading implant protocol and to assess the accuracy of an aluminum framework fabricated from a digital impression. Five master casts reproducing different edentulous maxillae with four tilted implants were used. Four scan bodies were screwed onto the low-profile abutments, and a digital intraoral scanner was used to perform five digital impressions of each master cast. To assess trueness, a metal framework of the best digital impression was produced with computer-aided design/computer-assisted manufacture (CAD/CAM) technology and passive fit was assessed with the Sheffield test. Gaps between the frameworks and the implant analogs were measured with a stereomicroscope. To assess precision, three-dimensional (3D) point cloud processing software was used to measure the deviations between the five digital impressions of each cast by producing a color map. The deviation values were grouped in three classes, and differences were assessed between class 2 (representing lower discrepancies) and the assembled classes 1 and 3 (representing the higher negative and positive discrepancies, respectively). The frameworks showed a mean gap of < 30 μm (range: 2 to 47 μm). A statistically significant difference was found between the two groups by the 3D point cloud software, with higher frequencies of points in class 2 than in grouped classes 1 and 3 (P < .001). Within the limits of this in vitro study, it appears that a digital impression may represent a reliable method for fabricating full-arch implant frameworks with good passive fit when tilted implants are present.

Effects of implant angulation, impression material, and variation in arch curvature width on implant transfer model accuracy.

PubMed

Akalin, Zerrin Fidan; Ozkan, Yasemin Kulak; Ekerim, Ahmet

2013-01-01

The effects of implant angulation, impression material, and variation in width of the arch curvature on transfer models were evaluated. Three edentulous maxillary epoxy resin models were fabricated, and six internal-connection implant analogs were placed in different locations and different angulations in each model. In the first model, implants were positioned in the canine, first premolar, and first molar regions, and all analogs were positioned parallel to each other and perpendicular to the horizontal crestal plane (parallel model). In the second model, analogs were positioned in same regions (canine, first premolar, and first molar), but three of them were positioned with 10-degree buccal angulations (versus the horizontal crestal plane) (angular model). In the third model, analogs were inserted in the lateral incisor, canine, and second molar regions and parallel to each other (wide-arch model). Eighteen impressions of each model were made with each of the three materials--condensation silicone, polyvinyl siloxane, and polyether--and impressions were poured and kept at room temperature for 24 hours. They were then observed under a toolmaker's microscope, with epoxy resin models of each group used as references. Distance deformations between implants in each model in the x- and y-axes were recorded separately. Implant angulation deformations were recorded in the x-z plane. Statistical evaluations were performed with analysis of variance and the least significant difference post hoc test. Angular model measurements showed the greatest deformation values (P < .05). All impression materials showed deformation, and the polyether impression models showed statistically significantly less deformation in angular measurements (P < .05). The models with implants placed parallel to each other exhibited greater accuracy than a model with implants placed at angles to each other.

Standards in C.S.E. and G.C.E.: English and Mathematics. Working Paper No. 9.

ERIC Educational Resources Information Center

Schools Council, London (England).

Attainment tests in English and mathematics were administered to a total sample of 2,011/15-year old students. The English test consisted of a composition and a test battery of objective items. Marking of the composition was made by the test designer on a rapid first-impression reading. The objective test battery consisted of a comprehension test,…

"Know More Hepatitis:" CDC's National Education Campaign to Increase Hepatitis C Testing Among People Born Between 1945 and 1965.

PubMed

Jorgensen, Cynthia; Carnes, C Amanda; Downs, Alycia

2016-01-01

In 2012, CDC issued recommendations calling for those born between 1945 and 1965, or baby boomers, to get tested for the hepatitis C virus. To help implement this recommendation, CDC developed "Know More Hepatitis," a multimedia national education campaign. Guided by behavioral science theories and formative research, the campaign used multiple strategies to reach baby boomers and health-care providers with messages encouraging baby boomers to get tested for hepatitis C. With a limited campaign budget, the "Know More Hepatitis" campaign relied mostly on donated time and space from broadcast and print outlets. Donated placements totaled approximately $14.7 million, which reflected a more than 12-to-1 return on the campaign investment. This effort was supplemented with a small, paid digital advertising campaign. Combining audience impressions from both paid and donated campaign efforts resulted in more than 1.2 billion audience impressions.

Effects of sulfur-based hemostatic agents and gingival retraction cords handled with latex gloves on the polymerization of polyvinyl siloxane impression materials

PubMed Central

MACHADO, Carlos Eduardo Palhares; GUEDES, Carlos Gramani

2011-01-01

Objectives This study investigated the possible interactions between three addition silicone materials (Express®, Aquasil Ultra® and Adsil®), three hemostatic agents (ferric sulfate, StatGel FS®; aluminum sulfate, GelCord®; and aluminum chloride, Hemostop®) and gingival retraction cords previously handled with latex gloves to determine whether direct contact with medicaments or indirect contamination by latex in conditions similar to those found in clinical practice inhibit or affect the setting of the impression materials. Material and Methods A portable device for the simultaneous test of several specimens was specifically developed for this study. Polymerization inhibition was analyzed by examination of the impressions and the molded surface. Ten trials were performed for each addition silicone material used in the study, at a total of 240 study samples. Results All the samples tested (N=240) were nonreactive regardless of the type of combination used. Conclusions Aluminum sulfate, ferric sulfate and aluminum chloride hemostatic solutions did not show any inhibitory potential on the addition silicone samples under study, and there were no changes in polymerization as a result of contact between addition silicone and retraction cords handled with latex gloves. PMID:22230998

Effects of sulfur-based hemostatic agents and gingival retraction cords handled with latex gloves on the polymerization of polyvinyl siloxane impression materials.

PubMed

Machado, Carlos Eduardo Palhares; Guedes, Carlos Gramani

2011-01-01

This study investigated the possible interactions between three addition silicone materials (Express®, Aquasil Ultra® and Adsil®), three hemostatic agents (ferric sulfate, StatGel FS®; aluminum sulfate, GelCord®; and aluminum chloride, Hemostop®) and gingival retraction cords previously handled with latex gloves to determine whether direct contact with medicaments or indirect contamination by latex in conditions similar to those found in clinical practice inhibit or affect the setting of the impression materials. A portable device for the simultaneous test of several specimens was specifically developed for this study. Polymerization inhibition was analyzed by examination of the impressions and the molded surface. Ten trials were performed for each addition silicone material used in the study, at a total of 240 study samples. All the samples tested (N=240) were nonreactive regardless of the type of combination used. Aluminum sulfate, ferric sulfate and aluminum chloride hemostatic solutions did not show any inhibitory potential on the addition silicone samples under study, and there were no changes in polymerization as a result of contact between addition silicone and retraction cords handled with latex gloves.

Spontaneous evaluative inferences and their relationship to spontaneous trait inferences.

PubMed

Schneid, Erica D; Carlston, Donal E; Skowronski, John J

2015-05-01

Three experiments are reported that explore affectively based spontaneous evaluative impressions (SEIs) of stimulus persons. Experiments 1 and 2 used modified versions of the savings in relearning paradigm (Carlston & Skowronski, 1994) to confirm the occurrence of SEIs, indicating that they are equivalent whether participants are instructed to form trait impressions, evaluative impressions, or neither. These experiments also show that SEIs occur independently of explicit recall for the trait implications of the stimuli. Experiment 3 provides a single dissociation test to distinguish SEIs from spontaneous trait inferences (STIs), showing that disrupting cognitive processing interferes with a trait-based prediction task that presumably reflects STIs, but not with an affectively based social approach task that presumably reflects SEIs. Implications of these findings for the potential independence of spontaneous trait and evaluative inferences, as well as limitations and important steps for future study are discussed. (c) 2015 APA, all rights reserved).

Exercise promotes positive impression formation towards both men and women.

PubMed

Kanarek, Robin B; Mathes, Wendy Foulds; D'Anci, Kristen E

2012-06-01

Exercise is endorsed for its physiological and psychological benefits, and has been proposed to have positive effects on impression formation. To test this proposal, 62 female and 44 male college students read one of three brief descriptions of either a fictitious male or female "target" student. The descriptions varied only in exercise level: no exercise; moderate exercise and intensive exercise. Participants then rated the fictitious student on 38 personality traits. Ratings of characteristics that are associated with exercise (e.g. athletic; energetic) increased, while ratings associated with the lack of exercise (e.g. lazy; weak) decreased as a function of the reported level of exercise. Exercise level also positively influenced ratings of characteristics not related to exercise. These data show that even minimal information about exercise is an important component of first impressions in both men and women. Copyright © 2012 Elsevier Ltd. All rights reserved.

Cultural differences in the primacy effect for person perception.

PubMed

Noguchi, Kenji; Kamada, Akiko; Shrira, Ilan

2014-06-01

Previous work has shown there are robust differences in how North Americans and East Asians form impressions of people. The present research examines whether the tendency to weigh initial information more heavily-the primacy effect-may be another component of these cultural differences. Specifically, we tested whether Americans would be more likely to use first impressions to guide person perception, compared to Japanese participants. In this experiment, participants read a vignette that described a target person's behaviour, then rated the target's personality. Before reading the vignette, some trait information was given to create an expectation about the target's personality. The data revealed that Americans used this initial information to guide their judgments of the target, whereas the Japanese sample based their judgments on all the information more evenly. Thus, Americans showed a stronger primacy effect in their impression formation than Japanese participants, who engaged in more data-driven processing. © 2013 International Union of Psychological Science.

School Discipline in Moral Disarray

ERIC Educational Resources Information Center

Goodman, Joan F.

2006-01-01

It is argued that current school disciplinary policies are ineffective instruments for delivering moral messages: they are poorly justified; fail to distinguish moral violations (violence, vandalism, deception) from conventional school-limited violations (attendance, dress codes, eating venues), leaving the impression that dress code violations…

An Examination of a Music Appreciation Method Incorporating Tactile Sensations from Artificial Vibrations

NASA Astrophysics Data System (ADS)

Ideguchi, Tsuyoshi; Yoshida, Ryujyu; Ooshima, Keita

We examined how test subject impressions of music changed when artificial vibrations were incorporated as constituent elements of a musical composition. In this study, test subjects listened to several music samples in which different types of artificial vibration had been incorporated and then subjectively evaluated any resulting changes to their impressions of the music. The following results were obtained: i) Even if rhythm vibration is added to a silent component of a musical composition, it can effectively enhance musical fitness. This could be readily accomplished when actual sounds that had been synchronized with the vibration components were provided beforehand. ii) The music could be listened to more comfortably by adding not only a natural vibration extracted from percussion instruments but also artificial vibration as tactile stimulation according to intentional timing. Furthermore, it was found that the test subjects' impression of the music was affected by a characteristic of the artificial vibration. iii) Adding vibration to high-frequency areas can offer an effective and practical way of enhancing the appeal of a musical composition. iv) The movement sensations of sound and vibration could be experienced when the strength of the sound and vibration are modified in turn. These results suggest that the intentional application of artificial vibration could result in a sensitivity amplification factor on the part of a listener.

Impressions of functional food consumers.

PubMed

Saher, Marieke; Arvola, Anne; Lindeman, Marjaana; Lähteenmäki, Liisa

2004-02-01

Functional foods provide a new way of expressing healthiness in food choices. The objective of this study was to apply an indirect measure to explore what kind of impressions people form of users of functional foods. Respondents (n=350) received one of eight versions of a shopping list and rated the buyer of the foods on 66 bipolar attributes on 7-point scales. The shopping lists had either healthy or neutral background items, conventional or functional target items and the buyer was described either as a 40-year-old woman or man. The attribute ratings revealed three factors: disciplined, innovative and gentle. Buyers with healthy background items were perceived as more disciplined than those having neutral items on the list, users of functional foods were rated as more disciplined than users of conventional target items only when the background list consisted of neutral items. Buyers of functional foods were regarded as more innovative and less gentle, but gender affected the ratings on gentle dimension. The impressions of functional food users clearly differ from those formed of users of conventional foods with a healthy image. The shopping list method performed well as an indirect method, but further studies are required to test its feasibility in measuring other food-related impressions.

Impression cytology: a novel sampling technique for conjunctival cytology of the feline eye.

PubMed

Eördögh, Réka; Schwendenwein, Ilse; Tichy, Alexander; Nell, Barbara

2015-07-01

Impression cytology is a noninvasive investigation of the ocular surface. It uses the adhesive features of different filter papers to collect a monolayer of epithelial cells from the cornea and/or conjunctiva. Samples obtained by impression cytology exhibit all characteristics of an ideal cytology specimen. The aim of this study was to test the feasibility of impression cytology and determine the most appropriate filter paper to achieve maximum diagnostic value of the feline eye. Ten healthy cats. The study was conducted in two phases. In the first phase, eight different filter papers (FPs) with various pore sizes were tested: 3.0-, 1.2-, 0.8-, 0.45-, 0.22-, 0.05- and 0.025-μm cellulose acetate papers and a 0.4-μm Biopore membrane (BM). Samples were obtained from the superior bulbar and from the inferior palpebral conjunctiva. In the second phase, three different sampling methods - with and without topical anesthesia, and with topical anesthesia and drying of the conjunctiva - were compared employing the BM encased in the intended BM device (BMD). Samples were evaluated for cellularity and quality of cells. In the first phase, samples obtained from the superior bulbar conjunctiva with the BM had the most sufficient cellularity and quality. In the second phase, BMD with topical anesthesia and additional drying of the conjunctiva was the most ideal method. The BMD may prove to be a suitable diagnostic tool for clinicians. Sampling is quick, processing is simple, and a large area of intact cells can be harvested. © 2014 American College of Veterinary Ophthalmologists.

Unproven methods in cancer treatment.

PubMed

Hauser, S P

1993-07-01

The nature-based and nontoxic image makes application of unproven methods in oncology attractive in contrast to application of a mechanized scientific medicine. The application frequency of these treatments ranges from 10% to greater than 60%. Increasingly, the promoters try to create a scientific impression through a pseudologic cancer theory, a harmless diagnostic test, and a holistic treatment of every cancer. Of the big variety of unproven methods, which are summarized in 11 groups in this review, the following are discussed: anthroposophic and other mistletoe preparations; homeopathy; Maharishi Ayur-Veda; unproven anticancer diets; orthomolecular medicine, including ascorbic acid; and methods supposedly stimulating unspecific and specific defense mechanisms. In conclusion, physicians should beware of and have knowledge of currently used unproven cancer treatments for epidemiologic, social, economic, and scientific reasons.

Clinical characterisation and cytological study of dry eye in patients with autoimmune disease.

PubMed

Guannan, Huang; Long, Su; Xia, Hua; Dong, Wang; Shaozhen, Zhao

2018-03-01

To assess the clinical characteristics and changes in ocular surface cytology of dry eye in patients with systemic autoimmune disease. The case-control study was conducted in the Second Hospital of Tianjin Medical University, Tianjin, China, from February 2016 to January 2017, and comprised systemic autoimmune disease patients and healthy controls. Schirmer's I test, tear breakup time test, and fluorescein staining were performed on all subjects. Both groups were evaluated for dry eye with the current diagnostic criteria. Conjunctival impression cytology and the morphology of epithelial cells were observed in both groups of subjects. Flow cytometry was used to identify the amount of apoptosis. SPSS 15 was used to analyse the data. Each of the two groups had 60(50%) subjects each. The morbidity of dry eye in the control group was 17(28.3%), while it was 31(51.7%) in the patients (p<0.01). Among the patients with dry eye, the severity level of cells obtained by conjunctival impression sampling was significantly higher in patients than in controls (p<0.01). The percentage of conjunctival epithelial cells undergoing apoptosis was higher in patients with dry eye than in patients without dry eye in each group, and among patients with dry eye, the percentage of conjunctival epithelial cells undergoing apoptosis was higher in the patients than in controls (p<0.01 each). The cell injury on the ocular surface was more serious in subjects with dry eye in systemic autoimmune disease than in subjects with dry eye in healthy controls.

The impact of recreational video game play on children's and adolescents' cognition.

PubMed

Blumberg, Fran C; Altschuler, Elizabeth A; Almonte, Debby E; Mileaf, Maxwell I

2013-01-01

Current empirical findings show linkages between recreational video game play and enhanced cognitive skills, primarily among young adults. However, consideration of this linkage among children and adolescents is sparse. Thus, discussions about facilitating transfer of cognitive skills from video game play to academic tasks among children and adolescents remains largely uninformed by research. To inform this discussion, we review available research concerning the cognitive benefits of video game play among children and adolescents and their impressions of video games as learning tools as these impressions may impact their application of cognitive skills used during game play to academic tasks. Copyright © 2013 Wiley Periodicals, Inc., A Wiley Company.

Prevention of Cross-contamination Risk by Disinfection of Irreversible Hydrocolloid Impression Materials with Ozonated Water.

PubMed

Savabi, Omid; Nejatidanesh, Farahnaz; Bagheri, Kamran Poshang; Karimi, Leila; Savabi, Ghazal

2018-01-01

Disinfection of dental impression is mandatory for preventing the cross infection between dental staff and dental laboratory. Ozone as a disinfectant can be used in various ways in dentistry. The aim of this study was to evaluate the efficacy of ozonated water for disinfection of irreversible hydrocolloid impression materials and preventing cross-contamination. Thirty-two circular specimens (1 cm diameter and 2 mm thickness) of irreversible hydrocolloid impression material were made. Thirty specimens were contaminated with Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (ATCC 51299), and Candida albicans (PTCC 5027). Except control samples ( n = 2), the other specimens were immersed in ozonated water for 5 and 10 min (5 sample each group). Trypsin was used for separating microorganisms. Diluted microbial solution was analyzed microbiologically for colony-forming units (CFUs). Two-way repeated measure ANOVA and Scheffe post hoc test were used for data analysis (α = 0.05). The number of CFUs after disinfection with ozonated water was decreased significantly (11.84%, 61.55%, and 20.27% after 5 min and 11.03%, 14.50%, and 16.99% after 10 min for P. aeruginosa , S. aureus , and C. albicans , respectively) ( P < 0.001). Increasing the time of disinfection resulted in significant reduction in a number of S. aureus only ( P < 0.001) although they did not vanish microorganisms completely. Immersion of irreversible hydrocolloid impression material in ozonated water for 10 min will not lead to complete disinfection but decreases the microorganisms to a level that can prevent infection transmission.

Comparison of Two Validated Voiding Questionnaires and Clinical Impression in Children With Lower Urinary Tract Symptoms: ICIQ-CLUTS Versus Akbal Survey.

PubMed

Goknar, Nilüfer; Oktem, Faruk; Demir, Aysegul D; Vehapoglu, Aysel; Silay, Mesrur S

2016-08-01

To compare the correlation of 2 commonly used and validated voiding questionnaires (ICIQ-CLUTS and Akbal's) according to the physician's clinical impressions. Also, we investigated the reliability of these instruments in children with lower urinary tract symptoms (LUTS). Akbal's questionnaires and ICIQ-CLUTS forms were completed by children between 5 and 18 years old with and without LUTS and by their parents. The data were classified into 3 age groups (5-9, 10-13, 14-18). The reliability of Akbal and ICIQ-CLUTS was investigated by using Cronbach's α (≥0.7 is indicated acceptability). The total scores of the tools were compared with the physician's clinical impression (Kendall's tau b-test). A total of 154 children (LUTS: n = 88, controls: n = 66) were prospectively enrolled into the study. The reliability of both instruments was excellent (Cronbach's alpha scores; Akbal = 0.811, ICIQ-CLUTS children version: 0.728 and ICIQ-CLUTS parental version: 0.746). When we compared by Kendal tau, Akbal was better correlated with physician's clinical impression. In addition, the children version of ICIQ-CLUTS was better correlated than parental version. The results of our study provide that both tools are reliable and objective to grade the LUTS in pediatric population. Although both surveys were significantly correlated with clinical impression, the consistency of Akbal's questionnaire is found superior than that of ICIQ-CLUTS. Copyright © 2016 Elsevier Inc. All rights reserved.

Accuracy of different impression materials in parallel and nonparallel implants

PubMed Central

Vojdani, Mahroo; Torabi, Kianoosh; Ansarifard, Elham

2015-01-01

Background: A precise impression is mandatory to obtain passive fit in implant-supported prostheses. The aim of this study was to compare the accuracy of three impression materials in both parallel and nonparallel implant positions. Materials and Methods: In this experimental study, two partial dentate maxillary acrylic models with four implant analogues in canines and lateral incisors areas were used. One model was simulating the parallel condition and the other nonparallel one, in which implants were tilted 30° bucally and 20° in either mesial or distal directions. Thirty stone casts were made from each model using polyether (Impregum), additional silicone (Monopren) and vinyl siloxanether (Identium), with open tray technique. The distortion values in three-dimensions (X, Y and Z-axis) were measured by coordinate measuring machine. Two-way analysis of variance (ANOVA), one-way ANOVA and Tukey tests were used for data analysis (α = 0.05). Results: Under parallel condition, all the materials showed comparable, accurate casts (P = 0.74). In the presence of angulated implants, while Monopren showed more accurate results compared to Impregum (P = 0.01), Identium yielded almost similar results to those produced by Impregum (P = 0.27) and Monopren (P = 0.26). Conclusion: Within the limitations of this study, in parallel conditions, the type of impression material cannot affect the accuracy of the implant impressions; however, in nonparallel conditions, polyvinyl siloxane is shown to be a better choice, followed by vinyl siloxanether and polyether respectively. PMID:26288620

Collection of Wet-Origin Footwear Impressions on Various Surfaces Using an Electrostatic Dust Print Lifter.

PubMed

Hong, Sungwook; Park, Miseon

2018-01-19

Electrostatic dust print lift method is known to be able to recover only dry-origin footwear impression. However, the wet-origin footwear impression could also be recovered using this method. As the amount of dust accumulated before deposition of the wet-origin footwear impression increased, the intensity of the footwear impression lifted with this method became stronger. If the footwear impression is not affected by moisture after it is made, the 28-h old wet-origin footwear impression could be recovered using this method. The intensity of the lifted footwear impression did not decrease significantly even when the number of sequential steps increased as long as the shoe sole is wet. However, when the moisture on the shoe sole depleted, the intensity of the footwear impression decreased sharply. This method has the advantage of being able to enhance the footwear impression without being affected by the footwear impressions deposited in the past. © 2018 American Academy of Forensic Sciences.

Similarity to the Self Affects Memory for Impressions of Others

PubMed Central

Leshikar, Eric D.; Gutchess, Angela H.

2017-01-01

The present studies investigated whether similarity to the self influenced memory for impressions of others. We predicted that similarity to the self would facilitate impression memory for others, paralleling the self-reference effect found when information is processed relative to the self. We were interested in how the initial valence of the impression, whether positive or negative, affected impression memory. Across two experiments, participants formed impressions while viewing faces paired with traits and behaviors. After recognition, participants rated the self-descriptiveness of the studied traits allowing impression memory to be sorted into high-, medium-, and low-self-similarity. For positive impressions, similar others were remembered better than dissimilar others. For negative impressions, similar others were remembered more poorly than dissimilar others. These results illustrate that similarity to the self has multifaceted effects on person memory, leading to memory enhancement in the case of people given positive impressions, but reducing memory for people associated with negative impressions. PMID:28936392

High-resolution MR imaging for dental impressions: a feasibility study.

PubMed

Boldt, Julian; Rottner, Kurt; Schmitter, Marc; Hopfgartner, Andreas; Jakob, Peter; Richter, Ernst-Jürgen; Tymofiyeva, Olga

2018-04-01

Magnetic resonance imaging is an emerging technology in dental medicine. While low-resolution MRI has especially provided means to examine the temporomandibular joint due to its anatomic inaccessibility, it was the goal of this study to assess whether high-resolution MRI is capable of delivering a dataset sufficiently precise enough to serve as digital impression of human teeth. An informed and consenting patient in need of dental restoration with fixed partial dentures was chosen as subject. Two prepared teeth were measured using MRI and the dataset subjected to mathematical processing before Fourier transformation. After reconstruction, a 3D file was generated which was fed into an existing industry standard CAD/CAM process. A framework for a fixed dental prosthesis was digitally modeled and manufactured by laser-sintering. The fit in situ was found to be acceptable by current clinical standards, which allowed permanent placement of the fixed prosthesis. Using a clinical whole-body MR scanner with the addition of custom add-on hardware, contrast enhancement, and data post-processing, resolution and signal-to-noise ratio were sufficiently achieved to allow fabrication of a dental restoration in an acquisition time comparable to the setting time of common dental impression materials. Furthermore, the measurement was well tolerated. The herein described method can be regarded as proof of principle that MRI is a promising option for digital impressions when fixed partial dentures are required.

The insanity defense: Related issues.

PubMed

Asokan, T V

2016-12-01

For the past 150 years, there is no change in the understanding and knowledge other than autonomy and capacity to choose the right and wrong for criminal liability. The alternative concept that human behavior is the result of an interaction between biological and environmental factors other than free choice failed to impress the criminal justice system because of a direct threat to a society's deep seated need to blame someone than themselves for criminal harms that occur. The insanity defense has a long history, and is evolved after many tests that have been tried and tested. McNaughton's rules stressed on "understandability of right and wrong" and "intellectual" rather than a moral or affective definition dominated in its formulation. Lack of control and irresistible drives or impulses were neglected Going by the current understanding of neurological evidences of compulsion and lack of impulse control, rationality tests without the inclusion of lack of control, seem to be outdated. Separate "Control determination" than the "Rationality determination" by the jurors may improve the accuracy of Juror's categorizations. There is a suggestion that Relevance ratio is ideal for 'Evidentiary relevance" and there should be a quality control on expert testimonies. With progress in neuroscience, the law may need to abandon or alter some of its current assumptions about the nature of voluntary conduct, which underlies various defenses.

The Effect of Instructing Impression Management Behaviors on Maximizing Applicants' Performance in the IELTS Speaking Test

ERIC Educational Resources Information Center

Namdar, Sara; Bagheri, Mohammad Sadegh

2012-01-01

Speaking proceeds under the constraint of time. While speaking, speakers are under constant pressure to follow the message being received and to formulate rapid responses to their partners. In the IELTS (International English Language Testing System) Speaking Test, the communicative nature of the interview creates an ideal situation for applicants…

A nationwide survey of public healthcare providers' impressions of family medicine specialists in Malaysia: a qualitative analysis of written comments.

PubMed

Chew, Boon-How; Cheong, Ai-Theng; Ismail, Mastura; Hamzah, Zuhra; A-Rashid, Mohd-Radzniwan; Md-Yasin, Mazapuspavina; Ali, Norsiah; Mohd-Salleh, Noridah; Bashah, Baizury

2016-01-07

To examine impressions of public healthcare providers/professionals (PHCPs) who are working closely with family medicine specialists (FMSs) at public health clinics. Cross-sectional study. This study is part of a larger national study on the perception of Malaysian public healthcare professionals on FMSs (PERMFAMS). PHCPs from three categories of health facility: hospitals, health clinics and health offices. Qualitative analyses of written comments of respondents' general impression of FMSs. The participants' response rate was 58.0% (780/1345), with almost equal proportions from each public healthcare facility. A total of 23 categories for each of the 648 impression comments were identified. The six emerging themes were: (1) importance of FMSs; (2) roles of FMSs; (3) clinical performance of FMSs; (4) attributes of FMSs; (5) FMS practice challenges; (6) misconception of FMS roles. Overall, FMS practice was perceived to be safe and able to provide effective treatments in a challenging medical discipline that was in line with the current standards of medical care and ethical and professional values. The areas of concern were in clinical performance expressed by PHCPs from some hospitals and the lack of personal attributes and professionalism among FMSs mentioned by PHCPs from health clinics and offices. FMSs were perceived to be capable of providing effective treatment and were considered to be important primary care physicians. There were a few negative impressions in some areas of FMS practice, which demanded attention by the FMSs themselves and the relevant authorities in order to improve efficiency and safeguard the fraternity's reputation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

A nationwide survey of public healthcare providers’ impressions of family medicine specialists in Malaysia: a qualitative analysis of written comments

PubMed Central

Cheong, Ai-Theng; Ismail, Mastura; Hamzah, Zuhra; A-Rashid, Mohd-Radzniwan; Md-Yasin, Mazapuspavina; Ali, Norsiah; Mohd-Salleh, Noridah; Bashah, Baizury

2016-01-01

Objective To examine impressions of public healthcare providers/professionals (PHCPs) who are working closely with family medicine specialists (FMSs) at public health clinics. Design Cross-sectional study. Setting This study is part of a larger national study on the perception of Malaysian public healthcare professionals on FMSs (PERMFAMS). Participants PHCPs from three categories of health facility: hospitals, health clinics and health offices. Main outcome measures Qualitative analyses of written comments of respondents’ general impression of FMSs. Results The participants’ response rate was 58.0% (780/1345), with almost equal proportions from each public healthcare facility. A total of 23 categories for each of the 648 impression comments were identified. The six emerging themes were: (1) importance of FMSs; (2) roles of FMSs; (3) clinical performance of FMSs; (4) attributes of FMSs; (5) FMS practice challenges; (6) misconception of FMS roles. Overall, FMS practice was perceived to be safe and able to provide effective treatments in a challenging medical discipline that was in line with the current standards of medical care and ethical and professional values. The areas of concern were in clinical performance expressed by PHCPs from some hospitals and the lack of personal attributes and professionalism among FMSs mentioned by PHCPs from health clinics and offices. Conclusions FMSs were perceived to be capable of providing effective treatment and were considered to be important primary care physicians. There were a few negative impressions in some areas of FMS practice, which demanded attention by the FMSs themselves and the relevant authorities in order to improve efficiency and safeguard the fraternity's reputation. PMID:26743703

INTESPACE's new thermal-vacuum test facility: SIMMER

NASA Technical Reports Server (NTRS)

Duprat, Raymond; Mouton, Andre

1992-01-01

The development of an European satellite market over the last 10 years, the industrialization of space applications, and the new requirements from satellite prime contractors have led INTESPACE to increase the test center's environmental testing capacities through the addition of a new thermal-vacuum test facility of impressive dimensions referred to as the SIMMER. The SIMMER is a simulator specifically created for the purpose of conducting acceptance tests of satellites and of large structures of the double launching ARIANE IV or half ARIANE V classes. The chamber is 8.3 meters long with a diameter of 10 meters. The conceptual design of a chamber in the horizontal plane and at floor level is in a view to simplify test preparation and to permit final electrical checks of the spacecraft in its actual test configuration prior to the closing of the chamber. The characteristics of the SIMMER complies with the requirements being currently defined in terms of thermal-vacuum tests: (1) thermal regulation (temperatures cycling between 100 K and 360 K); (2) clean vacuum (10(exp -6) mbar); (3) 600 measurement channels; and (4) 100 000 cleanliness class. The SIMMER is located in INTESPACE's space vehicle test complex in which a large variety of environmental test facilities are made available for having a whole test program completed under one and a same roof.

Surface Detail Reproduction and Effect of Disinfectant and Long-Term Storage on the Dimensional Stability of a Novel Vinyl Polyether Silicone Impression Material.

PubMed

Nassar, Usama; Chow, Ava K

2015-08-01

This study investigated the surface detail reproduction and dimensional stability of a vinyl polyether silicone (VPES) in comparison to a vinylpolysiloxane (VPS) material as a function of prolonged storage for up to 2 weeks. Heavy-body VPES (EXA'lence(TM) Fast Set) and VPS (Imprint(TM) 3 Quick Step) were compared. Forty impression ingots of each material were made using a stainless steel die as described by ANSI/ADA specification No. 19. Twenty impressions of each material were disinfected by immersion in a 2.5% buffered glutaraldehyde solution. Surface quality was assessed and scored immediately after making the ingots. Dimensional stability measurements were made immediately and repeated on the same ingots after 7 and 14 days storage in ambient laboratory conditions. Data were analyzed using the D'Agostino and Pearson omnibus normality test followed by two-way repeated measures ANOVA with post hoc Bonferroni tests. Values of p < 0.01 were deemed to be significant. Disinfected VPES and VPS specimens had significantly reduced dimensional changes at 7 and 14 days when compared with the nondisinfected ones (p < 0.0001). The dimensional stability of both materials was within ANSI/ADA specification No. 19's acceptable limit throughout the 2-week test period, regardless of whether they were disinfected. Out of the initial 80 ingots, 8 VPES and 1 VPS ingot scored a 2 on the surface detail test, while the remaining 71 ingots scored 1. Heavy-body fast-set VPES experienced minimal contraction in vitro after prolonged storage, though surface detail scores were not as consistent as those of the VPS tested. The least contraction occurred when the material was examined immediately after ingot production. © 2014 by the American College of Prosthodontists.

[Study on the effect of different impression methods on the marginal fit of all-ceramic crowns].

PubMed

Zhan, Lilin; Zeng, Liwei; Chen, Ping; Liao, Lan; Li, Shiyue; Liu, Renying

2015-08-01

To investigate the effect of three different impression methods on the marginal fit of all-ceramic crowns. The three methods include scanning silicone rubber impression, cast models, and direct optical impression. The polymethyl methacrylate (PMMA) material of a mandibular first molar in standard model was prepared with 16 models duplicated. The all-ceramic crowns were prepared using three different impression methods. Accurate impressions were made using silicone rubber, and the cast models were obtained. The PMMA models, silicone rubber impressions, and cast models were scanned, and digital models of three groups were obtained to produce 48 zirconia all-ceramic crowns with computer aided design/computer aided manufacture. The marginal fit of these groups was measured by silicone rubber gap impression. Statistical analysis was performed with SPSS 17.0 software. The marginal fit of direct optical impression groups, silicone rubber impression groups, cast model groups was (69.18±9.47), (81.04±10.88), (84.42±9.96) µm. A significant difference was observed in the marginal fit of the direct optical impression groups and the other groups (P<0.05). No statistically significant difference was observed in the marginal fit of the silicone rubber impression groups and the cast model groups (P>0.05). All marginal measurement sites are clinically acceptable by the three different impression scanning methods. The silicone rubber impression scanning method can be used for all-ceramic restorations.

"Therapeutic" Interventions of Clinicians in Standardized Interviews: A Test of the Social Competition Model

ERIC Educational Resources Information Center

Davis, John D.; And Others

1973-01-01

Describes experiment which tests and supports a social competition hypothesis in clinical intervention, suggesting that patient behavior is determined by clinician interview strategies which reflect their impressions of patient characteristics but are, in reality, a reflection of their own interview behavior. (Author/CJ)

Ring Two: The Librarians Comment

ERIC Educational Resources Information Center

American Libraries, 1978

1978-01-01

Three librarians give their impressions of sales representatives who work at library conventions. Henry Stewart discusses how they can be knowledgeable information sources about current products and services; Susan Martin describes how library automation vendors can help librarians learn about new technology; and Peggy Sullivan discusses the…

Can magneto-plasmonic nanohybrids efficiently combine photothermia with magnetic hyperthermia?

NASA Astrophysics Data System (ADS)

Espinosa, Ana; Bugnet, Mathieu; Radtke, Guillaume; Neveu, Sophie; Botton, Gianluigi A.; Wilhelm, Claire; Abou-Hassan, Ali

2015-11-01

Multifunctional hybrid-design nanomaterials appear to be a promising route to meet the current therapeutics needs required for efficient cancer treatment. Herein, two efficient heat nano-generators were combined into a multifunctional single nanohybrid (a multi-core iron oxide nanoparticle optimized for magnetic hyperthermia, and a gold branched shell with tunable plasmonic properties in the NIR region, for photothermal therapy) which impressively enhanced heat generation, in suspension or in vivo in tumours, opening up exciting new therapeutic perspectives.Multifunctional hybrid-design nanomaterials appear to be a promising route to meet the current therapeutics needs required for efficient cancer treatment. Herein, two efficient heat nano-generators were combined into a multifunctional single nanohybrid (a multi-core iron oxide nanoparticle optimized for magnetic hyperthermia, and a gold branched shell with tunable plasmonic properties in the NIR region, for photothermal therapy) which impressively enhanced heat generation, in suspension or in vivo in tumours, opening up exciting new therapeutic perspectives. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06168g

Accuracy evaluation of intraoral optical impressions: A clinical study using a reference appliance.

PubMed

Atieh, Mohammad A; Ritter, André V; Ko, Ching-Chang; Duqum, Ibrahim

2017-09-01

Trueness and precision are used to evaluate the accuracy of intraoral optical impressions. Although the in vivo precision of intraoral optical impressions has been reported, in vivo trueness has not been evaluated because of limitations in the available protocols. The purpose of this clinical study was to compare the accuracy (trueness and precision) of optical and conventional impressions by using a novel study design. Five study participants consented and were enrolled. For each participant, optical and conventional (vinylsiloxanether) impressions of a custom-made intraoral Co-Cr alloy reference appliance fitted to the mandibular arch were obtained by 1 operator. Three-dimensional (3D) digital models were created for stone casts obtained from the conventional impression group and for the reference appliances by using a validated high-accuracy reference scanner. For the optical impression group, 3D digital models were obtained directly from the intraoral scans. The total mean trueness of each impression system was calculated by averaging the mean absolute deviations of the impression replicates from their 3D reference model for each participant, followed by averaging the obtained values across all participants. The total mean precision for each impression system was calculated by averaging the mean absolute deviations between all the impression replicas for each participant (10 pairs), followed by averaging the obtained values across all participants. Data were analyzed using repeated measures ANOVA (α=.05), first to assess whether a systematic difference in trueness or precision of replicate impressions could be found among participants and second to assess whether the mean trueness and precision values differed between the 2 impression systems. Statistically significant differences were found between the 2 impression systems for both mean trueness (P=.010) and mean precision (P=.007). Conventional impressions had higher accuracy with a mean trueness of 17.0 ±6.6 μm and mean precision of 16.9 ±5.8 μm than optical impressions with a mean trueness of 46.2 ±11.4 μm and mean precision of 61.1 ±4.9 μm. Complete arch (first molar-to-first molar) optical impressions were less accurate than conventional impressions but may be adequate for quadrant impressions. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

An evaluation of the fit of metal-ceramic restorations made with an autoclaved silicone-based impression material.

PubMed

Kollefrath, Ralf; Savary, Marcel; Schwela, Jörg

2010-07-01

To demonstrate the clinical feasibility of autoclaving certain silicone impression materials in order to avoid potential cross-contamination during handling, transport, and subsequent processing. Semicritical devices are recommended to be treated at least with high-level disinfectants or actually steam sterilized at 134°C. To date dental impressions have been disinfected rather than sterilized, so the question remains should they be sterilized before being sent to the dental laboratory? Two identical impressions per case were made of metal-ceramic crown and fixed partial denture preparations on the same patient using addition type polyvinyl siloxane (PVS) impression materials (AFFINIS,® Coltene/Whaledent AG, 9450 Altstätten, Switzerland) in different trays. The first impression (IMPx1) was cleaned and treated with an intermediate-level disinfectant (FD 322--Fast Disinfection Spray, Dürr Dental, 74321 Bietigheim-Bissingen, Germany). The second impression (IMPx2) was cleaned, treated with an intermediate-level disinfectant as with IMPx1, subjected to a computer tomography (CT) scan with a dimensional resolution of ± 10 µm, steam sterilized, and then subjected to a second CT scan. The dimensional changes of the second impression after steam sterilization were calculated by comparing the overlay of the two CT scans and expressed by color coding of the impression graphics. After the second scan, the impression was sent to a dental laboratory to fabricate a metal-ceramic crown or metal-ceramic fixed partial denture restoration to the one produced from the first impression (IMPx1) subjected only to disinfection. This process was repeated for four clinical cases. Impressions made with AFFINIS® silicone impression materials in a rigid reinforced polycarbonate impression tray or in a metal dual-arch tray can be autoclaved. The overall dimensional stability of the impressions and the quality of single crowns and small fixed partial dentures made using IMPx2 was not compromised. The maximum dimensional differences at the preparations of the nonautoclaved and the autoclaved impressions were found to be within acceptable limits of about 50-100 µm. Steam sterilization of AFFINIS® impressions is possible without adversely affecting dimensional change. In addition, clinicians can clearly indicate to the dental practice and laboratory personnel that sterilization of the impressions has been performed, cross-contamination is unlikely, and the impressions present no apparent health hazard during transport and subsequent processing.

Comparison of Adaptation between the Major Connectors Fabricated from Intraoral Digital Impressions and Extraoral Digital Impressions.

PubMed

Gan, Ning; Ruan, Yaye; Sun, Jian; Xiong, Yaoyang; Jiao, Ting

2018-01-11

The objective was to compare the adaptation between the major connectors of removable partial dentures derived from intraoral digital impressions and extraoral digital impressions. Twenty-four volunteers were enrolled. Each volunteer received an intraoral digital impression and one extraoral digital impression digitized from conventional gypsum impression. A software was used to create the major connectors on digital impression datasets. After all the virtual major connectors designed from Group intraoral digital impressions (Group I) and Group extraoral digital impressions (Group E) were directly fabricated by 3D printing technique, the adaptation of the final major connectors in volunteers' mouths were measured. The adaptation ranged from 159.87 to 577.99 μm in Group I while from 120.83 to 536.17 μm in Group E. The adaptation of major connectors in Group I were found better at the midline palatine suture while the adaptation of major connectors in Group E were found better at the two sides of the palatal vault. In both groups, the highest accuracy in adaptation was revealed at the anterior margin of the major connectors. It is feasible to manufacture the major connectors by digital impression and 3D printing technique. Both the adaptation of the two kinds of digital impressions were clinical acceptable.

Wettability changes in polyether impression materials subjected to immersion disinfection.

PubMed

Shetty, Shweta; Kamat, Giridhar; Shetty, Rajesh

2013-07-01

Disinfection of impression materials prevents cross-contamination; however, the disinfectants may alter the wettability property. The purpose of this investigation was to evaluate the wettability changes of polyether impression material after immersing in four different chemical disinfectant solutions for a period of 10 min and 30 min, respectively. A total of 45 samples of polyether dental impression material (Impregum soft, 3MESPE, St. Paul, MN, USA) were randomly divided into nine groups with five specimens each. Each specimen was disc shaped, flat of 32 mm diameter and 3 mm thickness. The samples were immersed in four disinfectant solutions: 2% Glutaraldehyde, 5% sodium hypochlorite, 0.05% iodophor, and 5.25% phenol for 10 min and 30 min, respectively. The control was without disinfection. Wettability of the samples was assessed by measuring the contact angle by using the Telescopic Goniometer. Data were subjected to analysis of variance (Fisher's test) and Tukey's post hoc test for multiple comparisons at 5% level of significance. The contact angle of 20.21° ± 0.22° were recorded in the control samples. After 10 min, the samples that were immersed in 5% sodium hypochlorite and 5.25% phenol showed significant statistical increase in the contact angle as compared to the control (P < 0.001). After 30 min of disinfection, only the samples immersed in 0.05% iodophor showed there were no significant changes in the contact angle, whereas the other disinfectants significantly increased the contact angle and decreased the wettability of the polyether material. Within the limitations of the study, 2% glutaraldehyde proved safe for 10 min of immersion disinfection while 0.05% iodophor holds promise as an effective disinfectant without affecting the wettability of the material.

Wettability changes in polyether impression materials subjected to immersion disinfection

PubMed Central

Shetty, Shweta; Kamat, Giridhar; Shetty, Rajesh

2013-01-01

Background: Disinfection of impression materials prevents cross-contamination; however, the disinfectants may alter the wettability property. The purpose of this investigation was to evaluate the wettability changes of polyether impression material after immersing in four different chemical disinfectant solutions for a period of 10 min and 30 min, respectively. Materials and Methods: A total of 45 samples of polyether dental impression material (Impregum soft, 3MESPE, St. Paul, MN, USA) were randomly divided into nine groups with five specimens each. Each specimen was disc shaped, flat of 32 mm diameter and 3 mm thickness. The samples were immersed in four disinfectant solutions: 2% Glutaraldehyde, 5% sodium hypochlorite, 0.05% iodophor, and 5.25% phenol for 10 min and 30 min, respectively. The control was without disinfection. Wettability of the samples was assessed by measuring the contact angle by using the Telescopic Goniometer. Data were subjected to analysis of variance (Fisher's test) and Tukey's post hoc test for multiple comparisons at 5% level of significance. Results: The contact angle of 20.21° ± 0.22° were recorded in the control samples. After 10 min, the samples that were immersed in 5% sodium hypochlorite and 5.25% phenol showed significant statistical increase in the contact angle as compared to the control (P < 0.001). After 30 min of disinfection, only the samples immersed in 0.05% iodophor showed there were no significant changes in the contact angle, whereas the other disinfectants significantly increased the contact angle and decreased the wettability of the polyether material. Conclusion: Within the limitations of the study, 2% glutaraldehyde proved safe for 10 min of immersion disinfection while 0.05% iodophor holds promise as an effective disinfectant without affecting the wettability of the material. PMID:24130593

Evaluation of Surface Quality of Silicone Impression Materials after Disinfection with Ozone Water: An In vitro Study.

PubMed

Abinaya, K; Muthu Kumar, B; Ahila, S C

2018-01-01

To compare and evaluate the surface quality of silicone impression materials after ozone water disinfection. A total of 60 samples were prepared on a stainless steel die (American Dental Association specification no. 19 and International Standard of Organization - 4823). The samples were divided into four groups; each group contains 15 samples. Group A as control, Group B, C, and D disinfected with 2% glutaraldehyde, 5.25% sodium hypochlorite, and ozone water, respectively. The samples were made according to the manufacturer's instructions, and the samples were allowed to set in a thermostatically controlled water bath at 35°C ± 1°C and retrieved after 10 min. The surface qualities of the samples were measured in stereomicroscope with ×20 magnification. The data obtained were analyzed using Chi-square test, and the " P " value was calculated. The results showed that there were no differences in the surface quality among the Groups A, C, and D for addition silicone putty and light body and medium body impression materials than the Group B. This study concluded that ozone water disinfection showed least changes when compared to 5.25%sodium hypochloride and 2% glutaraldehyde disinfection for addition silicone putty , light body and medium body impression materials.

Field evaluation of a new aluminum alloy as a sacrificial anode for steel embedded in concrete

DOT National Transportation Integrated Search

1998-04-01

This is the final report for a study to evaluate the use of sacrificial cathodic protection for reinforced and prestressed concrete bridge members. Cathodic protection (CP) using impressed current is an accepted and common method used to provide corr...

Using HLM to Explore the Effects of Perceptions of Learning Environments and Assessments on Students' Test Performance

ERIC Educational Resources Information Center

Chu, Man-Wai; Babenko, Oksana; Cui, Ying; Leighton, Jacqueline P.

2014-01-01

The study examines the role that perceptions or impressions of learning environments and assessments play in students' performance on a large-scale standardized test. Hierarchical linear modeling (HLM) was used to test aspects of the Learning Errors and Formative Feedback model to determine how much variation in students' performance was explained…

Valuing Women in Management: An Impression Management Perspective of Gender Diversity.

ERIC Educational Resources Information Center

Gardner, William L., III; And Others

1994-01-01

Applies a model of impression management to explore the process whereby women in organizations present themselves to others and the impressions they create. Devotes particular attention to how these impressions influence women's experiences in organizations. Suggests future research direction for clarifying the impact of gender impression and…

Intraoral Digital Impressioning for Dental Implant Restorations Versus Traditional Implant Impression Techniques.

PubMed

Wilk, Brian L

2015-01-01

Over the course of the past two to three decades, intraoral digital impression systems have gained acceptance due to high accuracy and ease of use as they have been incorporated into the fabrication of dental implant restorations. The use of intraoral digital impressions enables the clinician to produce accurate restorations without the unpleasant aspects of traditional impression materials and techniques. This article discusses the various types of digital impression systems and their accuracy compared to traditional impression techniques. The cost, time, and patient satisfaction components of both techniques will also be reviewed.

Single Visit Feeding Appliance for 1-day-old Neonate with Cleft Palate Using Safe Dental Putty-Gauze Hybrid Impression Technique for Maxillary Impression.

PubMed

Rathee, Manu

2015-01-01

Cleft lip and palate is one of the most common craniofacial anomalies of humans. Intraoral impression making is the first clinical step in the fabrication of feeding appliance for infants with oro-nasal communication. It is difficult to control the flow of the impression material in the cleft area and undercuts in a child patient. This clinical report presents a simple and safe impression technique for maxillary impression making in neonates and infants with cleft palate. A gauze piece was used to confine the impression material during functional movements of sucking while impression making in an awake child to avoid the risk of aspiration or swallowing.

Fabrication of gas sensor based on field ionization from SWCNTs with tripolar microelectrode

NASA Astrophysics Data System (ADS)

Cai, Shengbing; Zhang, Yong; Duan, Zhemin

2012-12-01

We report the nanofabrication of a sulfur dioxide (SO2) sensor with a tripolar on-chip microelectrode utilizing a film of single-walled carbon nanotubes (SWCNTs) as the field ionization cathode, where the ion flow current and the partial discharge current generated by the field ionization process of gaseous molecules can be gauged to gas species and concentration. The variation of the sensitivity is less than 4% for all of the tested devices, and the sensor has selectivity against gases such as He, NO2, CO, H2, SO2 and O2. Further, the sensor response presents well-defined and reproducible linear behavior with regard to concentration in the range investigated and a detection limitation of <˜0.5 ppm for SO2. More importantly, a tripolar on-chip microelectrode with SWCNTs as a cathode exhibits an impressive performance with respect to stability and anti-oxidation behavior, which are significantly better than had been possible before in the traditional bipolar sensor under explicit circumstances at room temperature.

Reassessing the "traditional background hypothesis" for elevated MMPI and MMPI-2 Lie-scale scores.

PubMed

Rosen, Gerald M; Baldwin, Scott A; Smith, Ronald E

2016-10-01

The Lie (L) scale of the Minnesota Multiphasic Personality Inventory (MMPI) is widely regarded as a measure of conscious attempts to deny common human foibles and to present oneself in an unrealistically positive light. At the same time, the current MMPI-2 manual states that "traditional" and religious backgrounds can account for elevated L scale scores as high as 65T-79T, thereby tempering impression management interpretations for faith-based individuals. To assess the validity of the traditional background hypothesis, we reviewed 11 published studies that employed the original MMPI with religious samples and found that only 1 obtained an elevated mean L score. We then conducted a meta-analysis of 12 published MMPI-2 studies in which we compared L scores of religious samples to the test normative group. The meta-analysis revealed large between-study heterogeneity (I2 = 87.1), L scale scores for religious samples that were somewhat higher but did not approach the upper limits specified in the MMPI-2 manual, and an overall moderate effect size (d¯ = 0.54, p < .001; 95% confidence interval [0.37, 0.70]). Our analyses indicated that religious-group membership accounts, on average, for elevations on L of about 5 t-score points. Whether these scores reflect conscious "fake good" impression management or religious-based virtuousness remains unanswered. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

FTA liver impressions as DNA template for detecting and genotyping fowl adenovirus.

PubMed

Moscoso, Hugo; Bruzual, Jose J; Sellers, Holly; Hofacre, Charles L

2007-03-01

The feasibility of using liver impressions on Flinders Technology Associates (FTA filter paper for the collection, inactivation, and molecular analysis of fowl adenovirus (FAV) was evaluated. FAV I European Union (EU) serotype 1 spotted on FTA was shown to be inactivated using specific-pathogen-free (SPF) primary chicken embryo liver cell culture as indicated by absence of cytopathic effect. Sensitivity of the polymerase chain reaction (PCR) test using tenfold dilutions of allantoic fluid from 100 to 10-4 for the detection of adenovirus serotype 1 on FTA cards was determined to be 0.0005 mean tissue culture infectious dose per FTA spot. The stability of the DNA from liver impressions on the FTA was found to be 198 days when stored at -20 degrees C. In a trial, inclusion body hepatitis (IBH) was experimentally reproduced in SPF chickens inoculated with FAV I EU serogroup 1, 4, 8, or 11, which presented weakness, pallor, depression, dehydration, and mortality within 6 days after inoculation. PCR performed on FTA liver impressions from the inoculated birds was able to detect all four viruses, and the nucleotide sequence analysis of the amplified PCR products (1219 bp of the hexone gene) revealed the expected serotypes. In addition to the trial, 55 clinical samples were analyzed from liver impressions on FTA cards, and FAV was detected in 11 of 55 (20%). Sequencing analysis showed that the viruses were EU serotypes 4, 5, 9, and 10. The results demonstrate that FTA filter paper inactivates the FAV I and maintains the DNA template for molecular analysis.

In vivo Study of the Accuracy of Dual-arch Impressions.

PubMed

de Lima, Luciana Martinelli Santayana; Borges, Gilberto Antonio; Junior, Luiz Henrique Burnett; Spohr, Ana Maria

2014-06-01

This study evaluated in vivo the accuracy of metal (Smart®) and plastic (Triple Tray®) dual-arch trays used with vinyl polysiloxane (Flexitime®), in the putty/wash viscosity, as well as polyether (Impregum Soft®) in the regular viscosity. In one patient, an implant-level transfer was screwed on an implant in the mandibular right first molar, serving as a pattern. Ten impressions were made with each tray and impression material. The impressions were poured with Type IV gypsum. The width and height of the pattern and casts were measured in a profile projector (Nikon). The results were submitted to Student's t-test for one sample (α = 0.05). For the width distance, the plastic dual-arch trays with vinyl polysiloxane (4.513 mm) and with polyether (4.531 mm) were statistically wider than the pattern (4.489 mm). The metal dual-arch tray with vinyl polysiloxane (4.504 mm) and with polyether (4.500 mm) did not differ statistically from the pattern. For the height distance, only the metal dual-arch tray with polyether (2.253 mm) differed statistically from the pattern (2.310 mm). The metal dual-arch tray with vinyl polysiloxane, in the putty/wash viscosities, reproduced casts with less distortion in comparison with the same technique with the plastic dual-arch tray. The plastic or metal dual-arch trays with polyether reproduced cast with greater distortion. How to cite the article: Santayana de Lima LM, Borges GA, Burnett LH Jr, Spohr AM. In vivo study of the accuracy of dual-arch impressions. J Int Oral Health 2014;6(3):50-5.

Formability of a wrought Mg alloy evaluated by impression testing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mohamed, Walid; Gollapudi, Srikant; Charit, Indrajit

This study is focused on furthering our understanding of the different factors that influence the formability of Magnesium alloys. Towards this end, formability studies were undertaken on a wrought Mg-2Zn-1Mn (ZM21) alloy. In contrast to conventional formability studies, the impression testing method was adopted here to evaluate the formability parameter, B, at temperatures ranging from 298 to 473 K. The variation of B of ZM21 with temperature and its rather limited values were discussed in the light of different deformation mechanisms such as activation of twinning, slip, grain boundary sliding (GBS) and dynamic recrystallization (DRX). It was found that themore » material characteristics such as grain size, texture and testing conditions such as temperature and strain rate, were key determinants of the mechanism of plastic deformation. A by-product of this analysis was the observation of an interesting correlation between the Zener-Hollomon parameter, Z, and the ability of Mg alloys to undergo DRX.« less

Objective forensic analysis of striated, quasi-striated and impressed toolmarks

NASA Astrophysics Data System (ADS)

Spotts, Ryan E.

Following the 1993 Daubert v. Merrell Dow Pharmaceuticals, Inc. court case and continuing to the 2010 National Academy of Sciences report, comparative forensic toolmark examination has received many challenges to its admissibility in court cases and its scientific foundations. Many of these challenges deal with the subjective nature in determining whether toolmarks are identifiable. This questioning of current identification methods has created a demand for objective methods of identification - "objective" implying known error rates and statistically reliability. The demand for objective methods has resulted in research that created a statistical algorithm capable of comparing toolmarks to determine their statistical similarity, and thus the ability to separate matching and nonmatching toolmarks. This was expanded to the creation of virtual toolmarking (characterization of a tool to predict the toolmark it will create). The statistical algorithm, originally designed for two-dimensional striated toolmarks, had been successfully applied to striated screwdriver and quasi-striated plier toolmarks. Following this success, a blind study was conducted to validate the virtual toolmarking capability using striated screwdriver marks created at various angles of incidence. Work was also performed to optimize the statistical algorithm by implementing means to ensure the algorithm operations were constrained to logical comparison regions (e.g. the opposite ends of two toolmarks do not need to be compared because they do not coincide with each other). This work was performed on quasi-striated shear cut marks made with pliers - a previously tested, more difficult application of the statistical algorithm that could demonstrate the difference in results due to optimization. The final research conducted was performed with pseudostriated impression toolmarks made with chisels. Impression marks, which are more complex than striated marks, were analyzed using the algorithm to separate matching and nonmatching toolmarks. Results of the conducted research are presented as well as evidence of the primary assumption of forensic toolmark examination; all tools can create identifiably unique toolmarks.

How To Achieve Better Impressions in Computer-Mediated Communication?

ERIC Educational Resources Information Center

Liu, Yuliang; Ginther, Dean

This paper presents a review of the literature on impression formation in face-to-face (FtF) and computer-mediated communication (CMC) and provides impression management recommendations for CMC users in a variety of environments. The first section provides an introduction to impression formation. Factors affecting impression formation in FtF and…

A clinical comparison of cordless and conventional displacement systems regarding clinical performance and impression quality.

PubMed

Acar, Özlem; Erkut, Selim; Özçelik, Tuncer Burak; Ozdemır, Erdem; Akçil, Mehtap

2014-05-01

It is not clear whether newly introduced cordless displacement systems are better able to manage gingiva than conventional systems. The purpose of this in vivo study was to evaluate the gingival management ability of 4 different displacement methods with a standardized subgingival preparation finish line. The effects of 4 displacement techniques on gingival management and impression quality were evaluated by means of 6 evaluation criteria. A subgingival preparation finish line of between 1 and 2 mm was ensured, and the buccal aspects of 252 (n=63) teeth were clinically assessed for ease of application, time spent, bleeding, remnants, and dilatation. The complete reproduction of the preparation finish line and the bubble and void formations on polyether impressions were also evaluated. The data were statistically analyzed with the χ(2) test (α=.05). The Bonferroni correction was used to control Type I error for the pairwise comparison groups (α=.008). Statistically significant differences were found for all criteria among the groups (P<.05). The nonimpregnated displacement cord group was the least effective group in terms of bleeding and impression quality (P<.008). The aluminum chloride impregnated cord group and the displacement paste with cap group were found to be comparable in terms of remnants, dilatation, and impression quality (P>.008). The retraction cap with paste group showed better results for ease of application, time spent, and bleeding than the aluminum chloride impregnated cord group (P<.008). Although the group with aluminum chloride impregnated cord, displacement paste, and cap showed better results for dilatation, it was time consuming and difficult (P<.008). Except for the nonimpregnated cord group, all of the groups were comparable and clinically useful, with perfect or acceptable impression qualities. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Novel method of fabricating individual trays for maxillectomy patients by computer-aided design and rapid prototyping.

PubMed

Huang, Zhi; Wang, Xin-zhi; Hou, Yue-Zhong

2015-02-01

Making impressions for maxillectomy patients is an essential but difficult task. This study developed a novel method to fabricate individual trays by computer-aided design (CAD) and rapid prototyping (RP) to simplify the process and enhance patient safety. Five unilateral maxillectomy patients were recruited for this study. For each patient, a computed tomography (CT) scan was taken. Based on the 3D surface reconstruction of the target area, an individual tray was manufactured by CAD/RP. With a conventional custom tray as control, two final impressions were made using the different types of tray for each patient. The trays were sectioned, and in each section the thickness of the material was measured at six evenly distributed points. Descriptive statistics and paired t-test were used to examine the difference of the impression thickness. SAS 9.3 was applied in the statistical analysis. Afterwards, all casts were then optically 3D scanned and compared digitally to evaluate the feasibility of this method. Impressions of all five maxillectomy patients were successfully made with individual trays fabricated by CAD/RP and traditional trays. The descriptive statistics of impression thickness measurement showed slightly more uneven results in the traditional trays, but no statistical significance was shown. A 3D digital comparison showed acceptable discrepancies within 1 mm in the majority of cast areas. The largest difference of 3 mm was observed in the buccal wall of the defective areas. Moderate deviations of 1 to 2 mm were detected in the buccal and labial vestibular groove areas. This study confirmed the feasibility of a novel method of fabricating individual trays by CAD/RP. Impressions made by individual trays manufactured using CAD/RP had a uniform thickness, with an acceptable level of accuracy compared to those made through conventional processes. © 2014 by the American College of Prosthodontists.

The Michigan Alcoholism Screening Test (MAST): A Statistical Validation Analysis

ERIC Educational Resources Information Center

Laux, John M.; Newman, Isadore; Brown, Russ

2004-01-01

This study extends the Michigan Alcoholism Screening Test (MAST; M. L. Selzer, 1971) literature base by examining 4 issues related to the validity of the MAST scores. Specifically, the authors examine the validity of the MAST scores in light of the presence of impression management, participant demographic variables, and item endorsement…

Affective Dynamics of Leadership: An Experimental Test of Affect Control Theory

ERIC Educational Resources Information Center

Schroder, Tobias; Scholl, Wolfgang

2009-01-01

Affect Control Theory (ACT; Heise 1979, 2007) states that people control social interactions by striving to maintain culturally shared feelings about the situation. The theory is based on mathematical models of language-based impression formation. In a laboratory experiment, we tested the predictive power of a new German-language ACT model with…

An in vitro study to compare the accuracy of the master cast fabricated by four different transfer impression techniques for single-tooth implant replacement.

PubMed

Lahori, Manesh; Nagrath, Rahul; Agrawal, Prateek

2014-03-01

Single tooth implant retained crowns have become a recognized technique for the replacement of the missing teeth. With the predictable integration of implants, the emphasis is shifted towards precise prosthesis. Minor movement of the impression coping retained inside the impression material can occur during all the procedures, leading to the three-dimensional spatial inaccuracies in the master casts. Therefore, the present study was undertaken with the purpose to evaluate the accuracy of single-tooth implant impression techniques using four different impression copings, so as to obtain a precise definitive cast for a single-unit implant restoration. A maxillary acrylic resin model with a standard single implant in the first molar region was used to simulate a clinical situation. A total of 60 impressions were made with polyvinylsiloxane impression material, which were divided into four groups of 15 impressions each. Group I used non-modified square impression coping, while in group II, III and IV square impression coping were modified differently. Master casts fabricated for all the groups were analyzed to detect rotational position change of the hexagon on the implant replicas in the master casts in reference to the resin model. The master casts obtained with the roughened and adhesive-coated impression copings showed a lower amount of rotational movement than the masters casts achieved with the non-modified impression copings. Hence, the clinician should use sandblasted and adhesive coated impression copings to achieve a more accurate and precise orientation of the implant replicas in the laboratory master casts in single-tooth implant restorations.

Internationalisation of Higher Education in South Africa: A Historical Review

ERIC Educational Resources Information Center

Sehoole, Chika

2006-01-01

Current debates on internationalisation are couched in relation to globalisation, and gives the impression that this phenomenon is new. There is also a tendency to discuss internationalisation in relation to various rationales, with economic rationales being dominant. This article challenges the assumption that internationalisation is something…

Alternatives to Industrial Work Placement at Dublin Institute of Technology

ERIC Educational Resources Information Center

Bates, Catherine; Gamble, Elena

2011-01-01

In the current economic crisis, higher education graduates need transferable professional skills more than ever. They need resourcefulness, an ability to work reflectively, a sense of civic awareness and an impressive curriculum vitae. This case study analyses how Dublin Institute of Technology's Programme for Students Learning With Communities…

Accounting Students' Feedback on Feedback in Australian Universities: They're Less than Impressed

ERIC Educational Resources Information Center

Watty, Kim; de Lange, Paul; Carr, Rodney; O'Connell, Brendan; Howieson, Bryan; Jacobsen, Ben

2013-01-01

Undergraduate accounting students in Australian universities are dissatisfied with the feedback that they currently receive. Recent evidence from the Course Experience Questionnaire (CEQ, a national survey of Australian university graduates) suggests that the accounting discipline ranks poorly on assessment feedback when compared to other…

The Role of Attention-Placebo Influences in the Efficacy of Systematic Desensitization

ERIC Educational Resources Information Center

McReynolds, William T.; And Others

1973-01-01

Systematic desensitization was compared with two attention-placebo control treatments--one taken from Paul and one currently devised as an elaborate, highly impressive therapeutic'' experience--and no treatment. It was hypothesized that (a) fear reductions following desensitization would be no greater than those associated with an equally…

Give Us This Day Our Daily Breadth

ERIC Educational Resources Information Center

Duncan, Greg J.

2012-01-01

As with any discipline, the field of child development progresses by both deepening and broadening its conceptual and empirical perspective. The rewards to refinement are impressive, but there is little need for encouragement in this area, since existing disciplines, universities, and funding agencies reward depth. The current study makes the case…

Determining the gender of American martens and fishers at track plate stations

Treesearch

Keith M. Slauson; Richard L. Truex; William J. Zielinski

2008-01-01

Determining the gender of American martens (Martes americana) and fishers (M. pennanti) from track plate stations would significantly augment the information currently gathered from this simple and inexpensive survey method. We used track-plate impressions collected from captured individual martens and fishers of known gender to...

Emerging Understanding of Patterning in 4-Year-Olds

ERIC Educational Resources Information Center

Rittle-Johnson, Bethany; Fyfe, Emily R.; McLean, Laura E.; McEldoon, Katherine L.

2013-01-01

Young children have an impressive amount of mathematics knowledge, but past psychological research has focused primarily on their number knowledge. Preschoolers also spontaneously engage in a form of early algebraic thinking-patterning. In the current study, we assessed 4-year-old children's knowledge of repeating patterns on two occasions…

Five Bit, Five Gigasample TED Analog-to-Digital Converter Development.

DTIC Science & Technology

1981-06-01

pliers. TRW uses two sources at present: materials grown by Horizontal I Bridgman technique from Crystal Specialties, and Czochralski from MRI. The...the circuit modelling and circuit design tasks. A number of design iterations were required to arrive at a satisfactory design. In or-der to riake...made by modeling the TELD as a voltage-controlled current generator with a built-in time delay between impressed voltage and output current. Based on

Clinical evaluation of final impressions from three-dimensional printed custom trays.

PubMed

Sun, Yuchun; Chen, Hu; Li, Hong; Deng, Kehui; Zhao, Tian; Wang, Yong; Zhou, Yongsheng

2017-11-02

This study aimed to evaluate the quality of the final impressions taken by three-dimensional printed custom trays for edentulous patients. Custom trays were designed with or without saddle-shaped tissue stops and fabricated by three-dimensional printing techniques. Manually made trays with photocurable materials were produced as controls. Both 3D printed custom trays and manually made ones were used to take impressions from edentulous patients. After 3D scanning of the final impression, the impression materials were removed, thus the underneath tray surfaces were able to be scanned, allowing the thickness of the impression materials to be measured. Final impressions obtained by pre-border-molded 3D printed trays were scanned as references, to which the flange extension deviations and morphology deviations of the impressions taken by both 3D printed trays and manually made ones were calculated. The results showed that (1) impressions from 3D printed custom trays had better thickness distribution than that of manually made ones; (2) impression morphology deviations in non-marginal area were neither statistic different between 3D printed trays and manually made trays, nor between trays with and without tissue stops; and (3) final impressions taken by custom trays without pre-border-molding were tended to have insufficient flange extensions.

Accuracy of digital impressions of multiple dental implants: an in vitro study.

PubMed

Vandeweghe, Stefan; Vervack, Valentin; Dierens, Melissa; De Bruyn, Hugo

2017-06-01

Studies demonstrated that the accuracy of intra-oral scanners can be compared with conventional impressions for most indications. However, little is known about their applicability to take impressions of multiple implants. The aim of this study was to evaluate the accuracy of four intra-oral scanners when applied for implant impressions in the edentulous jaw. An acrylic mandibular cast containing six external connection implants (region 36, 34, 32, 42, 44 and 46) with PEEK scanbodies was scanned using four intra-oral scanners: the Lava C.O.S. and the 3M True Definition, Cerec Omnicam and 3Shape Trios. Each model was scanned 10 times with every intra-oral scanner. As a reference, a highly accurate laboratory scanner (104i, Imetric, Courgenay, Switzerland) was used. The scans were imported into metrology software (Geomagic Qualify 12) for analyses. Accuracy was measured in terms of trueness (comparing test and reference) and precision (determining the deviation between different test scans). Mann-Whitney U-test and Wilcoxon signed rank test were used to detect statistically significant differences in trueness and precision respectively. The mean trueness was 0.112 mm for Lava COS, 0.035 mm for 3M TrueDef, 0.028 mm for Trios and 0.061 mm for Cerec Omnicam. There was no statistically significant difference between 3M TrueDef and Trios (P = 0.262). Cerec Omnicam was less accurate than 3M TrueDef (P = 0.013) and Trios (P = 0.005), but more accurate compared to Lava COS (P = 0.007). Lava COS was also less accurate compared to 3M TrueDef (P = 0.005) and Trios (P = 0.005). The mean precision was 0.066 mm for Lava COS, 0.030 mm for 3M TrueDef, 0.033 mm for Trios and 0.059 mm for Cerec Omnicam. There was no statistically significant difference between 3M TrueDef and Trios (P = 0.119). Cerec Omnicam was less accurate compared to 3M TrueDef (P < 0.001) and Trios (P < 0.001), but no difference was found with Lava COS (P = 0.169). Lava COS was also less accurate compared to 3M TrueDef (P < 0.001) and Trios (P < 0.001). Based on the findings of this in vitro study, the 3M True Definition and Trios scanner demonstrated the highest accuracy. The Lava COS was found not suitable for taking implant impressions for a cross-arch bridge in the edentulous jaw. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Appearing smart: the impression management of intelligence, person perception accuracy, and behavior in social interaction.

PubMed

Murphy, Nora A

2007-03-01

Intelligence is an important trait that affects everyday social interaction. The present research utilized the ecological perspective of social perception to investigate the impression management of intelligence and strangers' evaluations of targets' intelligence levels. The ability to effectively portray an impression of intelligence to outside judges as well as interaction partners was appraised and the effect of impression management on the accurate judgment of intelligence was assessed. In addition, targets' behavior was studied in relation to impression management, perceived intelligence, and actual measured intelligence. Impression-managing targets appeared more intelligent to video judges but not to their interaction partner as compared to controls. The intelligence quotient (IQ) of impression-managing targets was more accurately judged than controls' IQ. Impression-managing targets displayed distinct nonverbal behavioral patterns that differed from controls. Looking while speaking was a key behavior: It significantly correlated with IQ, was successfully manipulated by impression-managing targets, and contributed to higher perceived intelligence ratings.

Evaluation of the fit of zirconia copings fabricated by direct and indirect digital impression procedures.

PubMed

Lee, Bora; Oh, Kyung Chul; Haam, Daewon; Lee, Joon-Hee; Moon, Hong-Seok

2018-02-07

Intraoral scanners are effective for direct digital impression when dental restorations are fabricated using computer-aided design and computer-aided manufacturing (CAD-CAM); however, if the abutment tooth cannot be dried completely or the prepared margin is placed subgingivally, accurate digital images cannot always be guaranteed. The purpose of this in vitro study was to compare the internal and marginal discrepancies of zirconia copings fabricated directly using an intraoral scanner with those fabricated indirectly with impression scanning. Forty-five resin dies fabricated with a 3-dimensional (3D) printer were divided into 3 groups: direct scanning (DS), impression scanning (IMP), and lost-wax casting (LW). For the DS group, a resin die was scanned with an intraoral scanner (Trios; 3Shape), whereas for the IMP group, impressions made with polyether were scanned with a cast scanner (D700; 3Shape). The zirconia copings were fabricated in the same way in the DS and IMP groups. For the LW group, impressions were made in the same way as in the IMP group, and Ni-Cr alloy copings were fabricated using LW. The marginal and internal discrepancies of the copings were measured by cementing them onto resin dies, embedding them in acrylic resin, and sectioning them in a buccolingual direction. The cement layer was measured, and the Kruskal-Wallis test was used to detect significant differences (α=.05). A nonparametric Friedman test was also performed to compare the measurements of each group by location (α=.05). The mean marginal discrepancies in the DS, IMP, and LW groups were 18.1 ±9.8, 23.2 ±17.2, and 32.3 ±18.6 μm (mean ±standard deviation), respectively. The mean internal discrepancies of the DS, IMP, and LW groups in the axial area were 38.0 ±9.1, 47.0 ±16.3, and 36.5 ±15.8 μm, and those in the occlusal area were 36.7 ±16.9, 33.4 ±21.6, and 44.5 ±31.9 μm, respectively. No statistically significant differences were found in marginal or internal discrepancies among groups (P>.05). Within the limitations of this study, the zirconia copings fabricated with CAD-CAM using different digitization methods and Ni-Cr copings fabricated using the lost-wax technique and casting produced clinically acceptable marginal and internal discrepancies. No significant differences were found among the DS, IMP, and LW groups. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

The effect of three variables on shear bond strength when luting a resin inlay to dentin.

PubMed

Lee, Jae-Ik; Park, Sung-Ho H

2009-01-01

The current study evaluated the effects of three variables on the shear bond strength of indirect composite restorations to human dentin. The three variables examined included immediate dentin sealing (IDS), the thinning of dentin adhesives by air-blowing before cementation and light-curing the dentin adhesive before cementation. One-hundred and eighty cylinder composite inlays, 2 mm in diameter and 3 mm in length, were made using a Tescera ATL system (BISCO Inc). Tooth disks 2-mm thick were obtained from 90 freshly-extracted human premolars. Two indirect composite cylinders were assigned to a single tooth disk. The discs were randomly divided into six groups according to the luting methods. AdheSE (Ivoclar Vivadent) was used as the dentin-bonding agent (DBA) for all groups. In Groups 1, 2 and 3, the dentin was sealed with AdheSE before taking the impression. After priming, the adhesive was lightly air-blown, then light-cured. On the other hand, the dentin was not sealed before taking the impression in Groups 4, 5 and 6. Regarding the application of DBA before cementation, it was gently air-blown and light-cured before cementation in Groups 1 and 4; whereas, it was heavily air-blown and light-cured in Groups 2 and 5 and gently air-blown but not light-cured in Groups 3 and 6. Z-250 and Duo-Link were used as luting materials. After 24-hours of storage, the bonded inlays were subjected to a shear bond test. For each luting material, one-way ANOVA and Duncan's Multiple Range Test were used to compare the shear bond strength. Paired t-tests were also performed to compare the shear strength between the two luting materials. All the statistical tests were carried out at the 95% confidence level. In Z-250, the results of the shear bond strength were as follows: Group 1(14.90MPa) > Group 2(12.22MPa), Group 4(12.16MPa) Group 5(9.61MPa), Group 3(9.60MPa) Group 6(3.54MPa)(p<0.05). In Duo-Link, the following shear bond strengths were obtained: Group 1(14.65MPa) > Group 2(13.04MPa), Group 4(12.66MPa) > Group 5(10.10MPa) > Group 3(8.40MPa) > Group 6(2.88MPa) (p<0.05). The mean shear bond strength of Z-250 and Duo-Link were not statistically different with the exception of Group 5. In conclusion, the shear bond strength of the indirect composite restoration to dentin can be improved by dentin sealing with DBA before taking an impression, gently air drying and light curing the DBA before the luting procedure.

Blinded evaluation of the effects of hyaluronic acid filler injections on first impressions.

PubMed

Dayan, Steven H; Arkins, John P; Gal, Thomas J

2010-11-01

Facial appearance has profound influence on the first impression that is projected to others. To determine the effects that complete correction of the nasolabial folds (NLFs) with hyaluronic acid (HA) filler has on the first impression one makes. Twenty-two subjects received injections of HA filler into the NLFs. Photographs of the face in a relaxed pose were taken at baseline, optimal correction visit, and 4 weeks after optimal correction. Three hundred four blinded evaluators completed a survey rating first impression on various measures of success for each photo. In total, 5,776 first impressions were recorded, totaling 46,208 individual assessments of first impression. Our findings indicate a significant improvement in mean first impression in the categories of dating success, attractiveness, financial success, relationship success, athletic success, and overall first impression at the optimal correction visit. At 4 weeks after the optimal correction visit, significance was observed in all categories measured: social skills, academic performance, dating success, occupational success, attractiveness, financial success, relationship success, athletic success, and overall first impression. Full correction of the NLFs with HA filler significantly and positively influences the first impression an individual projects. © 2010 by the American Society for Dermatologic Surgery, Inc.

Effect of Waterproofing Admixtures on the Flexural Strength and Corrosion Resistance of Concrete

NASA Astrophysics Data System (ADS)

Geetha, A.; Perumal, P.

2012-02-01

This paper deals about the flexural strength and corrosion behaviour of concrete using waterproofing admixtures. The effect of waterproofing admixtures on the corrosion behaviour of RCC specimen has been studied by conducting accelerated corrosion test. To identify the effect of corrosion in pull out strength, corrosion process was induced by means of accelerated corrosion procedure. To accelerate the reinforcement corrosion, direct electric current was impressed on the rebar embedded in the specimen using a DC power supply system that has a facility to adjust voltage. The addition of waterproofing admixtures also shows the improvement in the flexural strength of concrete has been studied by conducting flexural strength tests on the concrete prism specimen of size 100 × 100 × 500 mm with and without admixtures for various dosages and various curing periods of 7 and 28 days. The results showed that the presence of waterproofing admixtures always improves the corrosion resistance and thus increases the strength of concrete due to the hydrophobic action of waterproofing admixtures.

AnchorDock: Blind and Flexible Anchor-Driven Peptide Docking.

PubMed

Ben-Shimon, Avraham; Niv, Masha Y

2015-05-05

The huge conformational space stemming from the inherent flexibility of peptides is among the main obstacles to successful and efficient computational modeling of protein-peptide interactions. Current peptide docking methods typically overcome this challenge using prior knowledge from the structure of the complex. Here we introduce AnchorDock, a peptide docking approach, which automatically targets the docking search to the most relevant parts of the conformational space. This is done by precomputing the free peptide's structure and by computationally identifying anchoring spots on the protein surface. Next, a free peptide conformation undergoes anchor-driven simulated annealing molecular dynamics simulations around the predicted anchoring spots. In the challenging task of a completely blind docking test, AnchorDock produced exceptionally good results (backbone root-mean-square deviation ≤ 2.2Å, rank ≤15) for 10 of 13 unbound cases tested. The impressive performance of AnchorDock supports a molecular recognition pathway that is driven via pre-existing local structural elements. Copyright © 2015 Elsevier Ltd. All rights reserved.

Dark energy two decades after: observables, probes, consistency tests.

PubMed

Huterer, Dragan; Shafer, Daniel L

2018-01-01

The discovery of the accelerating universe in the late 1990s was a watershed moment in modern cosmology, as it indicated the presence of a fundamentally new, dominant contribution to the energy budget of the universe. Evidence for dark energy, the new component that causes the acceleration, has since become extremely strong, owing to an impressive variety of increasingly precise measurements of the expansion history and the growth of structure in the universe. Still, one of the central challenges of modern cosmology is to shed light on the physical mechanism behind the accelerating universe. In this review, we briefly summarize the developments that led to the discovery of dark energy. Next, we discuss the parametric descriptions of dark energy and the cosmological tests that allow us to better understand its nature. We then review the cosmological probes of dark energy. For each probe, we briefly discuss the physics behind it and its prospects for measuring dark energy properties. We end with a summary of the current status of dark energy research.

How components of facial width to height ratio differently contribute to the perception of social traits

PubMed Central

Lio, Guillaume; Gomez, Alice; Sirigu, Angela

2017-01-01

Facial width to height ratio (fWHR) is a morphological cue that correlates with sexual dimorphism and social traits. Currently, it is unclear how vertical and horizontal components of fWHR, distinctly capture faces’ social information. Using a new methodology, we orthogonally manipulated the upper facial height and the bizygomatic width to test their selective effect in the formation of impressions. Subjects (n = 90) saw pair of faces and had to select the face expressing better different social traits (trustworthiness, aggressiveness and femininity). We further investigated how sex and fWHR components interact in the formation of these judgements. Across experiments, changes along the vertical component better predicted participants' ratings rather than the horizontal component. Faces with smaller height were perceived as less trustworthy, less feminine and more aggressive. By dissociating fWHR and testing the contribution of its components independently, we obtained a powerful and discriminative measure of how facial morphology guides social judgements. PMID:28235081

Treatment comfort, time perception, and preference for conventional and digital impression techniques: A comparative study in young patients.

PubMed

Burhardt, Lukasz; Livas, Christos; Kerdijk, Wouter; van der Meer, Wicher Joerd; Ren, Yijin

2016-08-01

The aim of this crossover study was to assess perceptions and preferences for impression techniques in young orthodontic patients receiving alginate and 2 different digital impressions. Thirty-eight subjects aged 10 to 17 years requiring impressions for orthodontic treatment were randomly allocated to 3 groups that differed in the order that an alginate impressions and 2 different intraoral scanning procedures were administered. After each procedure, the patients were asked to score their perceptions on a 5-point Likert scale for gag reflex, queasiness, difficulty to breathe, uncomfortable feeling, perception of the scanning time, state of anxiety, and use of a powder, and to select the preferred impression system. Chairside time and maximal mouth opening were also registered. More queasiness (P = 0.00) and discomfort (P = 0.02) during alginate impression taking of the maxilla were perceived compared with the scans with the CEREC Omnicam (Sirona Dental Systems, Bensheim, Germany). There were no significant differences in perceptions between the alginate impressions and the Lava C.O.S. (3M ESPE, St Paul, Minn) and between the 2 scanners. Chairside times for the alginate impressions (9.7 ± 1.8 minutes) and the CEREC Omnicam (10.7 ± 1.8 minutes) were significantly lower (P <0.001) than for the Lava C.O.S. (17.8 ± 4.0 minutes). Digital impressions were favored by 51% of the subjects, whereas 29% chose alginate impressions, and 20% had no preference. Regardless of the significant differences in the registered times among the 3 impression-taking methods, the distributions of the Likert scores of time perception and maximal mouth opening were similar in all 3 groups. Young orthodontic patients preferred the digital impression techniques over the alginate method, although alginate impressions required the shortest chairside time. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Valence processing of first impressions in the dorsomedial prefrontal cortex: a near-infrared spectroscopy study.

PubMed

Yu, Chi-Lin; Wang, Min-Ying; Hu, Jon-Fan

2016-05-25

Previous studies have suggested that the dorsomedial prefrontal cortex (dmPFC) plays a central role in processing first impressions; however, little is known about how dmPFC processes different valences of first impressions. Moreover, it is still unclear as to whether the dmPFC shows lateralization or only induces different levels of activation when processing positive and negative impressions. To address these questions in the present study, the brain activities for the impression judgments expressed by participants were measured with near-infrared spectroscopy. For each real facial picture, participants were asked to evaluate their first impressions on a scale from 'bad' to 'good' using a keyboard. The results showed that although the right dmPFC has a higher sensitivity in processing impressions, both the hemispheres of dmPFC showed a significant trend where the activation of positive impressions was higher than the negative ones. Accordingly, it is proposed that the dmPFC acts as a single mechanism responsible for delineating the processing of first impressions rather than two lateralized systems. Therefore, a 'positivity dominance hypothesis' is also proposed, which states that dmPFC in both hemispheres have a higher sensitivity and priority for positive impressions than negative ones. The present study provides valuable findings with respect to the role of the dmPFC in the processes of first impression formation.

[Precision of digital impressions with TRIOS under simulated intraoral impression taking conditions].

PubMed

Yang, Xin; Sun, Yi-fei; Tian, Lei; Si, Wen-jie; Feng, Hai-lan; Liu, Yi-hong

2015-02-18

To evaluate the precision of digital impressions taken under simulated clinical impression taking conditions with TRIOS and to compare with the precision of extraoral digitalizations. Six #14-#17 epoxy resin dentitions with extracted #16 tooth preparations embedded were made. For each artificial dentition, (1)a silicone rubber impression was taken with individual tray, poured with type IV plaster,and digitalized with 3Shape D700 model scanner for 10 times; (2) fastened to a dental simulator, 10 digital impressions for each were taken with 3Shape TRIOS intraoral scanner. To assess the precision, best-fit algorithm and 3D comparison were conducted between repeated scan models pairwise by Geomagic Qualify 12.0, exported as averaged errors (AE) and color-coded diagrams. Non-parametric analysis was performed to compare the precisions of digital impressions and model images. The color-coded diagrams were used to show the deviations distributions. The mean of AE for digital impressions was 7.058 281 μm, which was greater than that of 4.092 363 μm for the model images (P<0.05). However, the means and medians of AE for digital impressions were no more than 10 μm, which meant that the consistency between the digital impressions was good. The deviations distribution was uniform in the model images,while nonuniform in the digital impressions with greater deviations lay mainly around the shoulders and interproximal surfaces. Digital impressions with TRIOS are of good precision and up to the clinical standard. Shoulders and interproximal surfaces scanning are more difficult.

Contact angle of unset elastomeric impression materials.

PubMed

Menees, Timothy S; Radhakrishnan, Rashmi; Ramp, Lance C; Burgess, John O; Lawson, Nathaniel C

2015-10-01

Some elastomeric impression materials are hydrophobic, and it is often necessary to take definitive impressions of teeth coated with some saliva. New hydrophilic materials have been developed. The purpose of this in vitro study was to compare contact angles of water and saliva on 7 unset elastomeric impression materials at 5 time points from the start of mixing. Two traditional polyvinyl siloxane (PVS) (Aquasil, Take 1), 2 modified PVS (Imprint 4, Panasil), a polyether (Impregum), and 2 hybrid (Identium, EXA'lence) materials were compared. Each material was flattened to 2 mm and a 5 μL drop of distilled water or saliva was dropped on the surface at 25 seconds (t0) after the start of mix. Contact angle measurements were made with a digital microscope at initial contact (t0), t1=2 seconds, t2=5 seconds, t3=50% working time, and t4=95% working time. Data were analyzed with a generalized linear mixed model analysis, and individual 1-way ANOVA and Tukey HSD post hoc tests (α=.05). For water, materials grouped into 3 categories at all time-points: the modified PVS and one hybrid material (Identium) produced the lowest contact angles, the polyether material was intermediate, and the traditional PVS materials and the other hybrid (EXA'lence) produced the highest contact angles. For saliva, Identium, Impregum, and Imprint 4 were in the group with the lowest contact angle at most time points. Modified PVS materials and one of the hybrid materials are more hydrophilic than traditional PVS materials when measured with water. Saliva behaves differently than water in contact angle measurement on unset impression material and produces a lower contact angle on polyether based materials. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Comparison of the accuracy of direct and indirect three-dimensional digitizing processes for CAD/CAM systems - An in vitro study.

PubMed

Vecsei, Bálint; Joós-Kovács, Gellért; Borbély, Judit; Hermann, Péter

2017-04-01

To compare the accuracy (trueness, precision) of direct and indirect scanning CAD/CAM methods. A master cast with prepared abutments and edentulous parts was created from polymethyl methacrylate (PMMA). A high-resolution industrial scanner was used to create a reference model. Polyvinyl-siloxane (PVS) impressions and digital impressions with three intraoral scanners (iTero, Cerec, Trios) were made (n=10 for each) from the PMMA model. A laboratory scanner (Scan CS2) was used to digitize the sectioned cast made from the PVS impressions. The stereolithographic (STL) files of the impressions (n=40) were exported. Each file was compared to the reference using Geomagic Verify software. Six points were assigned to enable virtual calliper measurement of three distances of varying size within the arch. Methods were compared using interquartile range regression and equality-of-variance tests for precision, and mixed-effects linear regression for trueness. The mean (SD) deviation of short distance measurements from the reference value was -40.3 (79.7) μm using the indirect, and 22.3 (40.0) μm using the direct method. For the medium distance, indirect measurements deviated by 5.2 (SD: 111.3) μm, and direct measurements by 115.8 (SD: 50.7) μm, on average; for the long distance, the corresponding estimates were -325.8 (SD: 134.1) μm with the indirect, and -163.5 (SD: 145.5) μm with the direct method. Significant differences were found between the two methods (p<0.05). With both methods, the shorter the distance, the more accurate results were achieved. Virtual models obtained by digital impressions can be more accurate than their conventional counterparts. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Accuracy of Intraoral Digital Impressions for Whole Upper Jaws, Including Full Dentitions and Palatal Soft Tissues.

PubMed

Gan, Ning; Xiong, Yaoyang; Jiao, Ting

2016-01-01

Intraoral digital impressions have been stated to meet the clinical requirements for some teeth-supported restorations, though fewer evidences were proposed for larger scanning range. The aim of this study was to compare the accuracy (trueness and precision) of intraoral digital impressions for whole upper jaws, including the full dentitions and palatal soft tissues, as well as to determine the effect of different palatal vault height or arch width on accuracy of intraoral digital impressions. Thirty-two volunteers were divided into three groups according to the palatal vault height or arch width. Each volunteer received three scans with TRIOS intraoral scanner and one conventional impression of whole upper jaw. Three-dimensional (3D) images digitized from conventional gypsum casts by a laboratory scanner were chose as the reference models. All datasets were imported to a specific software program for 3D analysis by "best fit alignment" and "3D compare" process. Color-coded deviation maps showed qualitative visualization of the deviations. For the digital impressions for palatal soft tissues, trueness was (130.54±33.95)μm and precision was (55.26±11.21)μm. For the digital impressions for upper full dentitions, trueness was (80.01±17.78)μm and precision was (59.52±11.29)μm. Larger deviations were found between intraoral digital impressions and conventional impressions in the areas of palatal soft tissues than that in the areas of full dentitions (p<0.001). Precision of digital impressions for palatal soft tissues was slightly better than that for full dentitions (p = 0.049). There was no significant effect of palatal vault height on accuracy of digital impressions for palatal soft tissues (p>0.05), but arch width was found to have a significant effect on precision of intraoral digital impressions for full dentitions (p = 0.016). A linear correlation was found between arch width and precision of digital impressions for whole upper jaws (r = 0.326, p = 0.034 for palatal soft tissues and r = 0.485, p = 0.002 for full dentitions). It was feasible to use the intraoral scanner to obtain digital impressions for whole upper jaws. Wider dental arch contributed to lower precision of an intraoral digital impression. It should be confirmed in further studies that whether accuracy of digital impressions for whole upper jaws is clinically acceptable.

Similarity to the Self Affects Memory for Impressions of Others in Younger and Older Adults

PubMed Central

Park, Jung M.; Gutchess, Angela H.

2015-01-01

Objectives. Similarity to the self has been shown to affect memory for impressions in younger adults, suggesting a self-reference effect in person memory. Because older adults show comparable self-reference effects, but prioritize memory for positive over negative information relative to young adults, we examined age differences in self-similarity effects on memory for positive and negative impressions. Method. Younger and older adults formed positive and negative impressions of others differing in the degree of similarity to the self (high, medium, low). Results. For positive impressions, both groups showed enhanced memory for self-similar others relative to dissimilar others, whereas for negative impressions, memory was poorer for those similar to the self. When collapsed across similarity to the self, younger adults remembered negative impressions better than older adults, but interestingly, older adults exhibited a trend for better memory for the positive impressions. Discussion. Results suggest that self-reference effects in impression memory are preserved with age and that older adults exhibit positivity effects in person memory consistent with previous findings. PMID:24389124

Fifteen years of APC/cyclosome: a short and impressive biography.

PubMed

Simpson-Lavy, Kobi J; Oren, Yifat S; Feine, Oren; Sajman, Julia; Listovsky, Tammy; Brandeis, Michael

2010-02-01

The APC/C (anaphase-promoting complex/cyclosome) discovered exactly 15 years ago by Avram Heshko and Marc Kirschner is by far the most complex ubiquitin ligase discovered so far. The APC/C is composed of roughly a dozen subunits and measures a massive 1.5 MDa. This huge complex, as well as its multiple modes of regulation, boasts impressive evolutionary conservation. One of its most puzzling features is its split personality: regulation of mitotic exit events on the one hand, and its ongoing activity during G(1)-phase, G(0)-phase and in terminally differentiated cells. The present short review is intended to provide a basic description of our current understanding of the APC/C, focusing on recent findings concerning its role in G(1)-phase and in differentiated cells.

Quantitative pilomotor axon reflex test: a novel test of pilomotor function.

PubMed

Siepmann, Timo; Gibbons, Christopher H; Illigens, Ben M; Lafo, Jacob A; Brown, Christopher M; Freeman, Roy

2012-11-01

Cutaneous autonomic function can be quantified by the assessment of sudomotor and vasomotor responses. Although piloerector muscles are innervated by the sympathetic nervous system, there are at present no methods to quantify pilomotor function. To quantify piloerection using phenylephrine hydrochloride in humans. Pilot study. Hospital-based study. Twenty-two healthy volunteers (18 males,4 females) aged 24 to 48 years participated in 6 studies. Piloerection was stimulated by iontophoresis of 1% phenylephrine. Silicone impressions of piloerection were quantified by number and area. The direct and indirect responses to phenylephrine iontophoresis were compared on both forearms after pre treatment to topical and subcutaneous lidocaine and iontophoresis of normal saline. Iontophoresis of phenylephrine induced piloerection in both the direct and axon reflex–mediated regions, with similar responses in both arms. Topical lidocaine blocked axon reflex–mediated piloerection post-iontophoresis (mean [SD], 66.6 [19.2] for control impressions vs 7.2 [4.3] for lidocaine impressions;P.001). Subcutaneous lidocaine completely blocked piloerection.The area of axon reflex–mediated piloerection was also attenuated in the lidocaine-treated region postiontophoresis (mean [SD], 46.2 [16.1]cm2 vs 7.2 [3.9]cm2; P.001). Piloerection was delayed in the axon reflex region compared with the direct region. Normal saline did not cause piloerection. Phenylephrine provoked piloerection directly and indirectly through an axon reflex–mediated response that is attenuated by lidocaine. Piloerection is not stimulated by iontophoresis of normal saline alone.The quantitative pilomotor axon reflex test (QPART) may complement other measures of cutaneous autonomic nerve fiber function.

The insanity defense: Related issues

PubMed Central

Asokan, T. V.

2016-01-01

For the past 150 years, there is no change in the understanding and knowledge other than autonomy and capacity to choose the right and wrong for criminal liability. The alternative concept that human behavior is the result of an interaction between biological and environmental factors other than free choice failed to impress the criminal justice system because of a direct threat to a society's deep seated need to blame someone than themselves for criminal harms that occur. The insanity defense has a long history, and is evolved after many tests that have been tried and tested. McNaughton's rules stressed on “understandability of right and wrong” and “intellectual” rather than a moral or affective definition dominated in its formulation. Lack of control and irresistible drives or impulses were neglected Going by the current understanding of neurological evidences of compulsion and lack of impulse control, rationality tests without the inclusion of lack of control, seem to be outdated. Separate “Control determination” than the “Rationality determination” by the jurors may improve the accuracy of Juror's categorizations. There is a suggestion that Relevance ratio is ideal for ‘Evidentiary relevance” and there should be a quality control on expert testimonies. With progress in neuroscience, the law may need to abandon or alter some of its current assumptions about the nature of voluntary conduct, which underlies various defenses PMID:28216769

First impressions count.

PubMed

Turner, Jonathan W; Moazzez, Rebecca; Banerjee, Avijit

2012-09-01

The art and craft of recording intra-oral anatomy successfully with dental impressions relies on the interaction of three critical factors--the 'golden triangle of impression-taking': an appreciation of the anatomical features to be recorded, the material used to take the impression and the clinical handling/operative technique applied. This paper aims to discuss the three factors and their inter-relationships, detailing clinical tips for successful, reproducible and consistent outcomes. Obtaining accurate dental impressions is the key to success in a wide range of clinical restorative procedures. This paper offers clinical advice to practitioners to plan and then take predictable, good quality impressions for their restorative cases.

A New Big Five: Fundamental Principles for an Integrative Science of Personality

ERIC Educational Resources Information Center

McAdams, Dan P.; Pals, Jennifer L.

2006-01-01

Despite impressive advances in recent years with respect to theory and research, personality psychology has yet to articulate clearly a comprehensive framework for understanding the whole person. In an effort to achieve that aim, the current article draws on the most promising empirical and theoretical trends in personality psychology today to…

Teaching Effectiveness, Impression Management, and Dysfunctional Behavior: Student Evaluation of Teaching Control Data

ERIC Educational Resources Information Center

Crumbley, D. Larry; Reichelt, Kenneth J.

2009-01-01

Purpose: Student evaluation of teaching (SET) questionnaires are used in many countries, although much current research questions the validity of these surveys. US research indicates that more than 90 percent of academic accounting departments use this performance measurement. This paper aims to focus on the validity of SET data.…

Hard Lines and Soft Scenes: Constituting Masculinities in the Prospectuses of All-Boys Elite Private Schools

ERIC Educational Resources Information Center

Gottschall, Kristina; Wardman, Natasha; Edgeworth, Kathryn; Hutchesson, Rachael; Saltmarsh, Sue

2010-01-01

Over the last decade, education researchers have been concerned with the "impression management" activities of schools in the current climate of school corporatisation. Among these activities is the dissemination of school prospectuses that, far from being merely arbitrary sources of information, are seen as strategic texts that…

The Treatment of Eating Disorder Clients in a Community-Based Partial Hospitalization Program.

ERIC Educational Resources Information Center

Levitt, John L.; Sansone, Randy A.

2003-01-01

Outlines a multi-faceted treatment approach to eating disorders within a partial hospital program that is affiliated with a community mental health hospital. Although empirical confirmation is not currently available, initial clinical impressions indicate that the program is facilitating the recovery of these difficult-to-treat individuals.…

Intraoral Scanner Technologies: A Review to Make a Successful Impression

PubMed Central

Richert, Raphaël; Goujat, Alexis; Venet, Laurent; Viguie, Gilbert; Viennot, Stéphane; Robinson, Philip; Farges, Jean-Christophe; Fages, Michel

2017-01-01

To overcome difficulties associated with conventional techniques, impressions with IOS (intraoral scanner) and CAD/CAM (computer-aided design and manufacturing) technologies were developed for dental practice. The last decade has seen an increasing number of optical IOS devices, and these are based on different technologies; the choice of which may impact on clinical use. To allow informed choice before purchasing or renewing an IOS, this article summarizes first the technologies currently used (light projection, distance object determination, and reconstruction). In the second section, the clinical considerations of each strategy such as handling, learning curve, powdering, scanning paths, tracking, and mesh quality are discussed. The last section is dedicated to the accuracy of files and of the intermaxillary relationship registered with IOS as the rendering of files in the graphical user interface is often misleading. This overview leads to the conclusion that the current IOS is adapted for a common practice, although differences exist between the technologies employed. An important aspect highlighted in this review is the reduction in the volume of hardware which has led to an increase in the importance of software-based technologies. PMID:29065652

Fit of lithium disilicate crowns fabricated from conventional and digital impressions assessed with micro-CT.

PubMed

Kim, Jae-Hyun; Jeong, Ji-Hye; Lee, Jin-Han; Cho, Hye-Won

2016-10-01

Although the number of lithium disilicate crowns fabricated with computer-aided design and computer-aided manufacturing (CAD-CAM) technology has increased, the accuracy of the prostheses produced by using digital pathways remains unknown. The purpose of this in vitro study was to compare marginal and internal discrepancies of lithium disilicate crowns fabricated from digital and conventional impressions. A typodont mandibular first molar was prepared for a lithium disilicate crown, and 20 duplicate dies were fabricated by milling poly(methyl methacrylate) resin blocks from laboratory scans. Four groups of 5 lithium disilicate crowns each were created by using a CS3500 (Carestream Dental) intraoral digital impression; Trios (3shape) intraoral digital impression; Ceramill Map400 (Amann Girrbach) extraoral digital impression; and a heat-press technique as a control group. All of the IPS e.max CAD (Ivoclar Vivadent AG) crowns were produced using a 5-axis milling engine (Ceramill Motion2). The lithium disilicate crowns were cemented with zinc phosphate cement under finger pressure. Marginal and internal discrepancies were measured using micro-computed tomography (SkyScan1172). One-way ANOVAs with the Tukey honest significant differences test were used for statistical analysis of the data (α=.05). The mean marginal discrepancies of CS3500 lithium disilicate crowns were 129.6 μm, 200.9 μm for Ceramill Map400, and 207.8 μm 176.1 μm for the heat-press technique; and the internal discrepancy volumes for CS3500 were 25.3 mm 3 , 40.7 mm 3 for Trios, 29.1 mm 3 for Ceramill Map400, and 29.1 and 31.4 mm 3 for the heat-press technique. The CS3500 group showed a significantly better marginal discrepancy than the other 3 groups and a smaller internal discrepancy volume than the Trios group (P<.05). Significant differences were found between IPS e.max CAD crowns produced using 2 intraoral digital impressions, whereas no differences were found between IPS e.max CAD crowns produced from an extraoral digital impression and IPS e.max Press crowns produced using a heat-press technique. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Validity and reliability of intraoral scanners compared to conventional gypsum models measurements: a systematic review.

PubMed

Aragón, Mônica L C; Pontes, Luana F; Bichara, Lívia M; Flores-Mir, Carlos; Normando, David

2016-08-01

The development of 3D technology and the trend of increasing the use of intraoral scanners in dental office routine lead to the need for comparisons with conventional techniques. To determine if intra- and inter-arch measurements from digital dental models acquired by an intraoral scanner are as reliable and valid as the similar measurements achieved from dental models obtained through conventional intraoral impressions. An unrestricted electronic search of seven databases until February 2015. Studies that focused on the accuracy and reliability of images obtained from intraoral scanners compared to images obtained from conventional impressions. After study selection the QUADAS risk of bias assessment tool for diagnostic studies was used to assess the risk of bias (RoB) among the included studies. Four articles were included in the qualitative synthesis. The scanners evaluated were OrthoProof, Lava, iOC intraoral, Lava COS, iTero and D250. These studies evaluated the reliability of tooth widths, Bolton ratio measurements, and image superimposition. Two studies were classified as having low RoB; one had moderate RoB and the remaining one had high RoB. Only one study evaluated the time required to complete clinical procedures and patient's opinion about the procedure. Patients reported feeling more comfortable with the conventional dental impression method. Associated costs were not considered in any of the included study. Inter- and intra-arch measurements from digital models produced from intraoral scans appeared to be reliable and accurate in comparison to those from conventional impressions. This assessment only applies to the intraoral scanners models considered in the finally included studies. Digital models produced by intraoral scan eliminate the need of impressions materials; however, currently, longer time is needed to take the digital images. PROSPERO (CRD42014009702). None. © The Author 2016. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Do impression management and self-deception distort self-report measures with content of dynamic risk factors in offender samples? A meta-analytic review.

PubMed

Hildebrand, Martin; Wibbelink, Carlijn J M; Verschuere, Bruno

Self-report measures provide an important source of information in correctional/forensic settings, yet at the same time the validity of that information is often questioned because self-reports are thought to be highly vulnerable to self-presentation biases. Primary studies in offender samples have provided mixed results with regard to the impact of socially desirable responding on self-reports. The main aim of the current study was therefore to investigate-via a meta-analytic review of published studies-the association between the two dimensions of socially desirable responding, impression management and self-deceptive enhancement, and self-report measures with content of dynamic risk factors using the Balanced Inventory of Desirable Responding (BIDR) in offender samples. These self-report measures were significantly and negatively related with self-deception (r = -0.120, p < 0.001; k = 170 effect sizes) and impression management (r = -0.158, p < 0.001; k = 157 effect sizes), yet there was evidence of publication bias for the impression management effect with the trim and fill method indicating that the relation is probably even smaller (r = -0.07). The magnitude of the effect sizes was small. Moderation analyses suggested that type of dynamic risk factor (e.g., antisocial cognition versus antisocial personality), incentives, and publication year affected the relationship between impression management and self-report measures with content of dynamic risk factors, whereas sample size, setting (e.g., incarcerated, community), and publication year influenced the relation between self-deception and these self-report measures. The results indicate that the use of self-report measures to assess dynamic risk factors in correctional/forensic settings is not inevitably compromised by socially desirable responding, yet caution is warranted for some risk factors (antisocial personality traits), particularly when incentives are at play. Copyright © 2018 Elsevier Ltd. All rights reserved.

Substance Use as Impression Management.

ERIC Educational Resources Information Center

Sharp, Mark J.; Getz, J. Greg

1996-01-01

Examines the function of substance use as an impression management tactic. Introductory psychology students (n=377) responded to a survey instrument measuring self-monitoring, perceived success in impression management, interaction anxiety, and self-esteem. Results suggest that alcohol use may serve an impression management function. (JPS)

Sensitivity of perianal tape impressions to diagnose pinworm (Syphacia spp.) infections in rats (Rattus norvegicus) and mice (Mus musculus).

PubMed

Hill, William Allen; Randolph, Mildred M; Mandrell, Timothy D

2009-07-01

We determined the sensitivity of perianal tape impressions to detect Syphacia spp. in rats and mice. We evaluated 300 rat and 200 mouse perianal impressions over 9 wk. Pinworm-positive perianal tape impressions from animals with worm burdens at necropsy were considered as true positives. Conversely, pinworm-negative perianal tape impressions from animals with worm burdens were considered false negatives. The sensitivity of perianal tape impressions for detecting Syphacia muris infections in rats was 100%, and for detecting Syphacia obvelata in mice was 85.5%. Intermittent shedding of Syphacia obvelata ova is the most probable explanation for the decreased sensitivity rate we observed in mice. We urge caution in use of perianal tape impressions alone for Syphacia spp. screening in sentinel mice and rats.

Trueness and precision of digital impressions obtained using an intraoral scanner with different head size in the partially edentulous mandible.

PubMed

Hayama, Hironari; Fueki, Kenji; Wadachi, Juro; Wakabayashi, Noriyuki

2018-03-01

It remains unclear whether digital impressions obtained using an intraoral scanner are sufficiently accurate for use in fabrication of removable partial dentures. We therefore compared the trueness and precision between conventional and digital impressions in the partially edentulous mandible. Mandibular Kennedy Class I and III models with soft silicone simulated-mucosa placed on the residual edentulous ridge were used. The reference models were converted to standard triangulated language (STL) file format using an extraoral scanner. Digital impressions were obtained using an intraoral scanner with a large or small scanning head, and converted to STL files. For conventional impressions, pressure impressions of the reference models were made and working casts fabricated using modified dental stone; these were converted to STL file format using an extraoral scanner. Conversion to STL file format was performed 5 times for each method. Trueness and precision were evaluated by deviation analysis using three-dimensional image processing software. Digital impressions had superior trueness (54-108μm), but inferior precision (100-121μm) compared to conventional impressions (trueness 122-157μm, precision 52-119μm). The larger intraoral scanning head showed better trueness and precision than the smaller head, and on average required fewer scanned images of digital impressions than the smaller head (p<0.05). On the color map, the deviation distribution tended to differ between the conventional and digital impressions. Digital impressions are partially comparable to conventional impressions in terms of accuracy; the use of a larger scanning head may improve the accuracy for removable partial denture fabrication. Copyright © 2018 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Where do young Irish women want Chlamydia-screening services to be set up? A qualitative study employing Goffman's impression management framework.

PubMed

Balfe, Myles; Brugha, Ruairi; O' Connell, Emer; McGee, Hannah; O' Donovan, Diarmuid

2010-01-01

We conducted interviews with 35 young women recruited from eight community healthcare rural and urban settings across two regions of Ireland. The aim of the study was to explore where these women thought Chlamydia-screening services should be located. Respondents wanted screening services to be located in settings where they would not be witnessed either asking for, or being asked to take, Chlamydia tests. Respondents were worried that their identities would become stigmatized if others were to find out that they had accepted screening. Findings are interpreted through Goffman's stigma and impression management framework. We conclude with public health recommendations.

Liquid Coatings for Reducing Corrosion of Steel in Concrete

NASA Technical Reports Server (NTRS)

MacDowell, Louis G.; Curran, Joseph

2003-01-01

Inorganic coating materials are being developed to slow or stop corrosion of reinforcing steel members inside concrete structures. It is much simpler and easier to use these coating materials than it is to use conventional corrosion-inhibiting systems based on impressed electric currents. Unlike impressed electrical corrosion-inhibiting systems, these coatings do not require continuous consumption of electrical power and maintenance of power-supply equipment. Whereas some conventional systems involve the use of expensive arc-spray equipment to apply the metallic zinc used as the sacrificial anode material, the developmental coatings can be applied by use of ordinary paint sprayers. A coating material of the type under development is formulated as a liquid containing blended metallic particles and/or moisture-attracting compounds. The liquid mixture is sprayed onto a concrete structure. Experiments have shown that even though such a coat resides on the exterior surface, it generates a protective galvanic current that flows to the interior reinforcing steel members. By effectively transferring the corrosion process from the steel reinforcement to the exterior coating, the protective current slows or stops corrosion of the embedded steel. Specific formulations have been found to meet depolarization criteria of the National Association of Corrosion Engineers (NACE) for complete protection of steel reinforcing bars ("rebar") embedded in concrete.

Making a Good Impression at Work: National Differences in Employee Impression Management Behaviors in Japan, Korea, and the United States.

PubMed

Krieg, Alexander; Ma, Li; Robinson, Patricia

2018-02-17

Impression management has important implications for success at work. This study explores differences in impression management in the East and West by examining the use of self-promotion, ingratiation, and exemplification directed towards three targets: supervisors, peers, and subordinates among 945 company employees from Japan, Korea, and the United States. Our results show that Korean employees used all three strategies most frequently, followed by United States, and then Japanese employees. Japanese and Korean employees used impression management strategies differentially across the three targets, and U.S. employees used impression management equally across targets. This elucidates how cultural trends in hierarchical relationships impact social behavior within the workplace. A follow-up mediation analysis found that relational or labor mobility fully mediated country differences in impression management, suggesting that culture is also reflected in larger social ecological trends in employee's ability and likelihood to change jobs, which also account for impression management strategy usage. Theoretical and practical implications for international business are discussed. This research may be useful in aligning strategies foreign employees might employ for using impression management when in Japan, Korea, and the United States.

Older and younger adults' first impressions from faces: similar in agreement but different in positivity.

PubMed

Zebrowitz, Leslie A; Franklin, Robert G; Hillman, Suzanne; Boc, Henry

2013-03-01

People readily form first impressions from faces, with consensual judgments that have significant social consequences. Similar impressions are shown by children, young adults (YA), and people from diverse cultures. However, this is the first study to systematically investigate older adults' (OA) impressions. OA and YA showed similar levels of within-age agreement in their impressions of competence, health, hostility, and trustworthiness. Both groups also showed stronger within- than between-age agreement. Consistent with other evidence for age-related increases in positivity, OA showed more positive impressions of the health, hostility, and trustworthiness of faces. These effects tended to be strongest for the most negatively valenced faces, suggesting that they derive from OA lesser processing of negative cues rather than greater processing of positive cues. An own-age bias in impressions was limited to greater OA positivity in impressions of the hostility of older faces, but not younger ones. Although OA and YA differed in vision and executive function, only OA slower processing speed contributed to age differences in impression positivity. Positivity effects in OA have not been previously linked to processing speed, and research investigating possible explanations for this effect would be worthwhile.

Older and Younger Adults’ First Impressions From Faces: Similar in Agreement but Different in Positivity

PubMed Central

Zebrowitz, Leslie A.; Franklin, Robert G.; Hillman, Suzanne; Boc, Henry

2014-01-01

People readily form first impressions from faces, with consensual judgments that have significant social consequences. Similar impressions are shown by children, young adults (YA), and people from diverse cultures. However, this is the first study to systematically investigate older adults’ (OA) impressions. OA and YA showed similar levels of within-age agreement in their impressions of competence, health, hostility, and trustworthiness. Both groups also showed stronger within- than between age agreement. Consistent with other evidence for age-related increases in positivity, OA showed more positive impressions of the health, hostility, and trustworthiness of faces. These effects tended to be strongest for the most negatively valenced faces, suggesting that they derive from OA lesser processing of negative cues rather than greater processing of positive cues. An own-age bias in impressions was limited to greater OA positivity in impressions of the hostility of older faces, but not younger ones. Although OA and YA differed in vision and executive function, only OA slower processing speed contributed to age differences in impression positivity. Positivity effects in OA have not been previously linked to processing speed, and research investigating possible explanations for this effect would be worthwhile. PMID:23276216

Line width measurement below 60 nm using an optical interferometer and artificial neural network

NASA Astrophysics Data System (ADS)

See, Chung W.; Smith, Richard J.; Somekh, Michael G.; Yacoot, Andrew

2007-03-01

We have recently described a technique for optical line-width measurements. The system currently is capable of measuring line-width down to 60 nm with a precision of 2 nm, and potentially should be able to measure down to 10nm. The system consists of an ultra-stable interferometer and artificial neural networks (ANNs). The former is used to generate optical profiles which are input to the ANNs. The outputs of the ANNs are the desired sample parameters. Different types of samples have been tested with equally impressive results. In this paper we will discuss the factors that are essential to extend the application of the technique. Two of the factors are signal conditioning and sample classification. Methods, including principal component analysis, that are capable of performing these tasks will be considered.

Impression Management Training: Conceptualization and Application to Personal Selling.

ERIC Educational Resources Information Center

Leathers, Dale G.

1988-01-01

Discusses the importance of impression management, an individual's conscious attempt to exercise control over selected communicative behaviors and cues for purposes of making a desired impression. Provides a comprehensive conceptualization of the impression-management process, and demonstrates how this process can facilitate effective training of…

21 CFR 872.3660 - Impression material.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Impression material. 872.3660 Section 872.3660...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3660 Impression material. (a) Identification. Impression material is a device composed of materials such as alginate or polysulfide intended to be placed...

21 CFR 872.3660 - Impression material.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Impression material. 872.3660 Section 872.3660...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3660 Impression material. (a) Identification. Impression material is a device composed of materials such as alginate or polysulfide intended to be placed...

21 CFR 872.6570 - Impression tube.

Code of Federal Regulations, 2010 CFR

2010-04-01

... DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6570 Impression tube. (a) Identification. An impression tube is a device consisting of a hollow copper tube intended to take an impression of a single tooth...) Classification. Class I (general controls). The device is exempt from the premarket notification procedures in...

Accuracy of Intraoral Digital Impressions for Whole Upper Jaws, Including Full Dentitions and Palatal Soft Tissues

PubMed Central

Gan, Ning; Xiong, Yaoyang; Jiao, Ting

2016-01-01

Intraoral digital impressions have been stated to meet the clinical requirements for some teeth-supported restorations, though fewer evidences were proposed for larger scanning range. The aim of this study was to compare the accuracy (trueness and precision) of intraoral digital impressions for whole upper jaws, including the full dentitions and palatal soft tissues, as well as to determine the effect of different palatal vault height or arch width on accuracy of intraoral digital impressions. Thirty-two volunteers were divided into three groups according to the palatal vault height or arch width. Each volunteer received three scans with TRIOS intraoral scanner and one conventional impression of whole upper jaw. Three-dimensional (3D) images digitized from conventional gypsum casts by a laboratory scanner were chose as the reference models. All datasets were imported to a specific software program for 3D analysis by "best fit alignment" and "3D compare" process. Color-coded deviation maps showed qualitative visualization of the deviations. For the digital impressions for palatal soft tissues, trueness was (130.54±33.95)μm and precision was (55.26±11.21)μm. For the digital impressions for upper full dentitions, trueness was (80.01±17.78)μm and precision was (59.52±11.29)μm. Larger deviations were found between intraoral digital impressions and conventional impressions in the areas of palatal soft tissues than that in the areas of full dentitions (p<0.001). Precision of digital impressions for palatal soft tissues was slightly better than that for full dentitions (p = 0.049). There was no significant effect of palatal vault height on accuracy of digital impressions for palatal soft tissues (p>0.05), but arch width was found to have a significant effect on precision of intraoral digital impressions for full dentitions (p = 0.016). A linear correlation was found between arch width and precision of digital impressions for whole upper jaws (r = 0.326, p = 0.034 for palatal soft tissues and r = 0.485, p = 0.002 for full dentitions). It was feasible to use the intraoral scanner to obtain digital impressions for whole upper jaws. Wider dental arch contributed to lower precision of an intraoral digital impression. It should be confirmed in further studies that whether accuracy of digital impressions for whole upper jaws is clinically acceptable. PMID:27383409

Influence of tray rigidity and impression technique on accuracy of polyvinyl siloxane impressions.

PubMed

Hoyos, Alex; Soderholm, Karl-Johan

2011-01-01

The aim of this study was to determine how tray rigidity and impression technique affect the accuracy of polyvinyl siloxane impressions. Disposable plastic trays and metallic Rim-Lock trays were used in combination with a heavy/light body technique or with two different putty-wash techniques. For each technique-tray combination, 10 impressions were made of a master cast with two steel abutments representing the mandibular right first premolar and second molar, between which a steel rod was placed at the ridge level. Each steel abutment had five marks, while the steel rod in between the two abutments had only one mark, which served as a reference point. With a universal measuring microscope, the x-, y-, and z-coordinates were recorded for each mark on the master cast and impressions. The distances between the different marks and the reference point on the impressions were calculated and compared with those of the master cast. All techniques used with the plastic trays had distances that were significantly different from the master cast (P < .05), while for the metal trays, it was only the heavy/light body technique that resulted in distances that were significantly different from the master cast (P < .05). Plastic trays produced less accurate impressions than metal trays. When metal trays were used, putty-based impressions were dimensionally better than heavy/light body impressions.

Interpretation of Appearance: The Effect of Facial Features on First Impressions and Personality

PubMed Central

Wolffhechel, Karin; Fagertun, Jens; Jacobsen, Ulrik Plesner; Majewski, Wiktor; Hemmingsen, Astrid Sofie; Larsen, Catrine Lohmann; Lorentzen, Sofie Katrine; Jarmer, Hanne

2014-01-01

Appearance is known to influence social interactions, which in turn could potentially influence personality development. In this study we focus on discovering the relationship between self-reported personality traits, first impressions and facial characteristics. The results reveal that several personality traits can be read above chance from a face, and that facial features influence first impressions. Despite the former, our prediction model fails to reliably infer personality traits from either facial features or first impressions. First impressions, however, could be inferred more reliably from facial features. We have generated artificial, extreme faces visualising the characteristics having an effect on first impressions for several traits. Conclusively, we find a relationship between first impressions, some personality traits and facial features and consolidate that people on average assess a given face in a highly similar manner. PMID:25233221

Interpretation of appearance: the effect of facial features on first impressions and personality.

PubMed

Wolffhechel, Karin; Fagertun, Jens; Jacobsen, Ulrik Plesner; Majewski, Wiktor; Hemmingsen, Astrid Sofie; Larsen, Catrine Lohmann; Lorentzen, Sofie Katrine; Jarmer, Hanne

2014-01-01

Appearance is known to influence social interactions, which in turn could potentially influence personality development. In this study we focus on discovering the relationship between self-reported personality traits, first impressions and facial characteristics. The results reveal that several personality traits can be read above chance from a face, and that facial features influence first impressions. Despite the former, our prediction model fails to reliably infer personality traits from either facial features or first impressions. First impressions, however, could be inferred more reliably from facial features. We have generated artificial, extreme faces visualising the characteristics having an effect on first impressions for several traits. Conclusively, we find a relationship between first impressions, some personality traits and facial features and consolidate that people on average assess a given face in a highly similar manner.

Two-step impression/ injection, an alternative putty/ wash impression technique: case report.

PubMed

Caputi, S; Murmura, G; Sinjari, B; Varvara, G

2012-01-01

We here describe a new technique for making a definitive impression that we refer to as the two-step impression/injection technique. This technique initially follows the classical one-step putty/ light-body impression technique with the polymerization of the putty and the light-body compound. This is then followed by the second step: injection of extra-light-body compound into the preparation through a hole in the metal stock tray. The aim of this additional step is to control the wash bulk and minimize the changes that can produce unfavorable impression results. This new two-step impression/injection technique allows displacement of soft tissues, such as the tongue, during the first seating of the putty and wash materials, while in the second step, the extra-light-body compound records all of the finer details without being compressed.

[The influence of affect on satisfaction with conversations and interpersonal impressions from the perspective of dyadic affective combinations].

PubMed

Ken, Fujiwara; Daibo, Ikuo

2013-12-01

This study examined the influence of affect on interpersonal relationships in a dyadic communication context. The combination of speakers' affective states was considered, as compared to previous studies which considered only the individual's affective state. The independent variables, in a between-subjects design, were affective condition (positive vs. negative) and affective combination (similar vs. dissimilar). Participants (N = 86) took a test on creative thinking and were given false feedback. Then they had a 6-minute conversation and answered questions about their satisfaction with the conversation and their impressions of their partner. Results showed that the two-factor interactions were significant for satisfaction with the conversation and interpersonal impressions (social desirability) of the partner. The scores for these variables in the positive affect condition were higher than in the negative affect condition only when the affective combination was dissimilar. These results show that individual's affect could not predict conversational outcomes. The results were discussed in terms of incorrect inferences about the partner's affective state and imbalanced conversation activity.

Reduction of metal artifact in three-dimensional computed tomography (3D CT) with dental impression materials.

PubMed

Park, W S; Kim, K D; Shin, H K; Lee, S H

2007-01-01

Metal Artifact still remains one of the main drawbacks in craniofacial Three-Dimensional Computed Tomography (3D CT). In this study, we tried to test the efficacy of additional silicone dental impression materials as a "tooth shield" for the reduction of metal artifact caused by metal restorations and orthodontic appliances. 6 phantoms with 4 teeth were prepared for this in vitro study. Orthodontic bracket, bands and amalgam restorations were placed in each tooth to reproduce various intraoral conditions. Standardized silicone shields were fabricated and placed around the teeth. CT image acquisition was performed with and without silicone shields. Maximum value, mean, and standard deviation of Hounsfield Units (HU) were compared with the presence of silicone shields. In every situation, metal artifacts were reduced in quality and quantity when silicone shields are used. Amalgam restoration made most serious metal artifact. Silicone shields made by dental impression material might be effective way to reduce the metal artifact caused by dental restoration and orthodontic appliances. This will help more excellent 3D image from 3D CT in craniofacial area.

Memory and disgust: Effects of appearance-congruent and appearance-incongruent information on source memory for food.

PubMed

Mieth, Laura; Bell, Raoul; Buchner, Axel

2016-01-01

The present study was stimulated by previous findings showing that people preferentially remember person descriptions that violate appearance-based first impressions. Given that until now all studies used faces as stimuli, these findings can be explained by referring to a content-specific module for social information processing that facilitates social orientation within groups via stereotyping and counter-stereotyping. The present study tests whether the same results can be obtained with fitness-relevant stimuli from another domain--pictures of disgusting-looking or tasty-looking food, paired with tasty and disgusting descriptions. A multinomial model was used to disentangle item memory, guessing and source memory. There was an old-new recognition advantage for disgusting-looking food. People had a strong tendency towards guessing that disgusting-looking food had been previously associated with a disgusting description. Source memory was enhanced for descriptions that disconfirmed these negative, appearance-based impressions. These findings parallel the results from the social domain. Heuristic processing of stimuli based on visual appearance may be complemented by intensified processing of incongruent information that invalidates these first impressions.

Influence of inner circular sealing area impression method on the retention of complete dentures.

PubMed

Wang, Cun-Wei; Shao, Qi; Sun, Hui-Qiang; Mao, Meng-Yun; Zhang, Xin-Wei; Gong, Qi; Xiao, Guo-Ning

2015-01-01

The aims of the present study were to describe an impression method of "inner circular sealing area" and to evaluate the effect of the method on retention, aesthetics and comfort of complete dentures, which lack labial base for patients with maxillary protrusions. Three patients were subjected to the experiment, and two sets of complete maxillary dentures were made for each patient; the first set was made without labial base via an inner circular sealing area method (experimental group) and the second had an intact base that was made with conventional methods (control group). Retention force tests were implemented with a tensile strength assessment device to assess the retention and a visual analogue scale (VAS) was used to evaluate the comfort between the two groups. Results showed larger retention force, better aesthetics and more comfort in the experimental group. The improved two-step impression method formed an inner circular sealing area that prevented damage to the peripheral border seal effect of the denture caused by incomplete bases and obtained better denture retention.

Non-auditory factors affecting urban soundscape evaluation.

PubMed

Jeon, Jin Yong; Lee, Pyoung Jik; Hong, Joo Young; Cabrera, Densil

2011-12-01

The aim of this study is to characterize urban spaces, which combine landscape, acoustics, and lighting, and to investigate people's perceptions of urban soundscapes through quantitative and qualitative analyses. A general questionnaire survey and soundwalk were performed to investigate soundscape perception in urban spaces. Non-auditory factors (visual image, day lighting, and olfactory perceptions), as well as acoustic comfort, were selected as the main contexts that affect soundscape perception, and context preferences and overall impressions were evaluated using an 11-point numerical scale. For qualitative analysis, a semantic differential test was performed in the form of a social survey, and subjects were also asked to describe their impressions during a soundwalk. The results showed that urban soundscapes can be characterized by soundmarks, and soundscape perceptions are dominated by acoustic comfort, visual images, and day lighting, whereas reverberance in urban spaces does not yield consistent preference judgments. It is posited that the subjective evaluation of reverberance can be replaced by physical measurements. The categories extracted from the qualitative analysis revealed that spatial impressions such as openness and density emerged as some of the contexts of soundscape perception. © 2011 Acoustical Society of America

Influence of Custom Trays, Dual-Arch Passive, Flexed Trays and Viscosities of Elastomeric Impression Materials on Working Dies.

PubMed

Arora, Mansi; Kohli, Shivani; Kalsi, Rupali

2016-05-01

Dual arch impression technique signifies an essential improvement in fixed prosthodontics and has numerous benefits over conventional impression techniques. The accuracy of working dies fabricated from dual arch impression technique remains in question because there is little information available in the literature. This study was conducted to compare the accuracy of working dies fabricated from impressions made from two different viscosities of impression materials using metal, plastic dual arch trays and custom made acrylic trays. The study samples were grouped into two groups based on the viscosity of impression material used i.e. Group I (monophase), whereas Group II consisted of Dual Mix technique using a combination of light and heavy body material. These were further divided into three subgroups A, B and C depending on the type of impression tray used (metal dual arch tray, plastic dual arch tray and custom made tray). Measurements of the master cast were made using profile projector. Descriptive statistics like mean, Standard Deviation (SD) were calculated for all the groups. One way analysis of variance (ANOVA) was used for multiple group comparisons. A p-value of 0.05 or less was considered statistically significant. The gypsum dies obtained with the three types of impression trays using two groups of impression materials were smaller than the master models in dimensions. The plastic dual arch trays produced dies which were the least accurate of the three groups. There was no significant difference in the die dimensions obtained using the two viscosities of impression materials.

Evaluation of digital dental models obtained from dental cone-beam computed tomography scan of alginate impressions

PubMed Central

Jiang, Tingting; Lee, Sang-Mi; Hou, Yanan; Chang, Xin

2016-01-01

Objective To investigate the dimensional accuracy of digital dental models obtained from the dental cone-beam computed tomography (CBCT) scan of alginate impressions according to the time elapse when the impressions are stored under ambient conditions. Methods Alginate impressions were obtained from 20 adults using 3 different alginate materials, 2 traditional alginate materials (Alginoplast and Cavex Impressional) and 1 extended-pour alginate material (Cavex ColorChange). The impressions were stored under ambient conditions, and scanned by CBCT immediately after the impressions were taken, and then at 1 hour intervals for 6 hours. After reconstructing three-dimensional digital dental models, the models were measured and the data were analyzed to determine dimensional changes according to the elapsed time. The changes within the measurement error were regarded as clinically acceptable in this study. Results All measurements showed a decreasing tendency with an increase in the elapsed time after the impressions. Although the extended-pour alginate exhibited a less decreasing tendency than the other 2 materials, there were no statistically significant differences between the materials. Changes above the measurement error occurred between the time points of 3 and 4 hours after the impressions. Conclusions The results of this study indicate that digital dental models can be obtained simply from a CBCT scan of alginate impressions without sending them to a remote laboratory. However, when the impressions are not stored under special conditions, they should be scanned immediately, or at least within 2 to 3 hours after the impressions are taken. PMID:27226958

Influence of Custom Trays, Dual-Arch Passive, Flexed Trays and Viscosities of Elastomeric Impression Materials on Working Dies

PubMed Central

Kohli, Shivani; Kalsi, Rupali

2016-01-01

Introduction Dual arch impression technique signifies an essential improvement in fixed prosthodontics and has numerous benefits over conventional impression techniques. The accuracy of working dies fabricated from dual arch impression technique remains in question because there is little information available in the literature. Aim This study was conducted to compare the accuracy of working dies fabricated from impressions made from two different viscosities of impression materials using metal, plastic dual arch trays and custom made acrylic trays. Materials and Methods The study samples were grouped into two groups based on the viscosity of impression material used i.e. Group I (monophase), whereas Group II consisted of Dual Mix technique using a combination of light and heavy body material. These were further divided into three subgroups A, B and C depending on the type of impression tray used (metal dual arch tray, plastic dual arch tray and custom made tray). Measurements of the master cast were made using profile projector. Descriptive statistics like mean, Standard Deviation (SD) were calculated for all the groups. One way analysis of variance (ANOVA) was used for multiple group comparisons. A p-value of 0.05 or less was considered statistically significant. Results The gypsum dies obtained with the three types of impression trays using two groups of impression materials were smaller than the master models in dimensions. Conclusion The plastic dual arch trays produced dies which were the least accurate of the three groups. There was no significant difference in the die dimensions obtained using the two viscosities of impression materials. PMID:27437342

Applied Chaos Level Test for Validation of Signal Conditions Underlying Optimal Performance of Voice Classification Methods

ERIC Educational Resources Information Center

Liu, Boquan; Polce, Evan; Sprott, Julien C.; Jiang, Jack J.

2018-01-01

Purpose: The purpose of this study is to introduce a chaos level test to evaluate linear and nonlinear voice type classification method performances under varying signal chaos conditions without subjective impression. Study Design: Voice signals were constructed with differing degrees of noise to model signal chaos. Within each noise power, 100…

Immersed transient eddy current flow metering: a calibration-free velocity measurement technique for liquid metals

NASA Astrophysics Data System (ADS)

Krauter, N.; Stefani, F.

2017-10-01

Eddy current flow meters are widely used for measuring the flow velocity of electrically conducting fluids. Since the flow induced perturbations of a magnetic field depend both on the geometry and the conductivity of the fluid, extensive calibration is needed to get accurate results. Transient eddy current flow metering has been developed to overcome this problem. It relies on tracking the position of an impressed eddy current system that is moving with the same velocity as the conductive fluid. We present an immersed version of this measurement technique and demonstrate its viability by numerical simulations and a first experimental validation.

Situated Action and the Management of Impression.

ERIC Educational Resources Information Center

Ginsburg, G. P.

Studies of the creation and management of impressions have advanced rapidly in recent years. However, relatively little empirical information has been provided about the processes by which impressions are created and managed in routine interaction and about the range of matters about which impressions are created. The excessive use of internal…

Apollo/Saturn C00.00.19.3 operations and maintenance. Cathodic protection of communication cables

NASA Technical Reports Server (NTRS)

1972-01-01

Operating and maintenance instructions for cathodic protection of communication cables at the Cape Kennedy Launch Complex are presented. The system is designed to prevent or arrest corrosion of communication cables buried in soil or submerged in water by impressing sufficient direct current from the rectifier through the anodes to the cable. This process neutralizes or counteracts current flowing from the cable into the soil or water, thus preventing or arresting corrosion of the cable sheath material.

DYNA3D/ParaDyn Regression Test Suite Inventory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Jerry I.

2016-09-01

The following table constitutes an initial assessment of feature coverage across the regression test suite used for DYNA3D and ParaDyn. It documents the regression test suite at the time of preliminary release 16.1 in September 2016. The columns of the table represent groupings of functionalities, e.g., material models. Each problem in the test suite is represented by a row in the table. All features exercised by the problem are denoted by a check mark (√) in the corresponding column. The definition of “feature” has not been subdivided to its smallest unit of user input, e.g., algorithmic parameters specific to amore » particular type of contact surface. This represents a judgment to provide code developers and users a reasonable impression of feature coverage without expanding the width of the table by several multiples. All regression testing is run in parallel, typically with eight processors, except problems involving features only available in serial mode. Many are strictly regression tests acting as a check that the codes continue to produce adequately repeatable results as development unfolds; compilers change and platforms are replaced. A subset of the tests represents true verification problems that have been checked against analytical or other benchmark solutions. Users are welcomed to submit documented problems for inclusion in the test suite, especially if they are heavily exercising, and dependent upon, features that are currently underrepresented.« less

3D evaluation of the effect of disinfectants on dimensional accuracy and stability of two elastomeric impression materials.

PubMed

Soganci, Gokce; Cinar, Duygu; Caglar, Alper; Yagiz, Ayberk

2018-05-31

The aim of this study was to determine and compare the dimensional changes of polyether and vinyl polyether siloxane impression materials under immersion disinfection with two different disinfectants in three time periods. Impressions were obtained from an edentulous master model. Sodium hypochlorite (5.25%) and glutaraldehyde (2%) were used for disinfection and measurements were done 30 min later after making impression before disinfection, after required disinfection period (10 min), and after 24 h storage at room temperature. Impressions were scanned using 3D scanner with 10 microns accuracy and 3D software was used to evaluate the dimensional changes with superimpositioning. Positive and negative deviations were calculated and compared with master model. There was no significant difference between two elastomeric impression materials (p>0.05). It was concluded that dimensional accuracy and stability of two impression materials were excellent and similar.

A pilot study measuring changes in student impressions before and after clinical training using a questionnaire based on the semantic differential technique.

PubMed

Tamura, Naomi; Terashita, Takayoshi; Ogasawara, Katsuhiko

2013-01-01

Students with a positive impression of their studies can become more motivated. This study measured the learning impact of clinical training by comparing student impressions before and after clinical training. The study included 32 students of radiological technology in their final year with the Division of Radiological Science and Technology, Department of Health Sciences, School of Medicine, Hokkaido University. To measure student impressions of x-ray examination training, we developed a questionnaire using the semantic differential technique. The resulting factor analysis identified 2 factors that accounted for 44.9% of the 10 bipolar adjective scales. Factor 1 represented a "resistance" impression of x-ray examination training, and factor 2 represented a "responsibility" impression. The differences in factor scores before and after the clinical training suggest that student impressions are affected by clinical training.

Managing and creating an image in the interview: the role of interviewee initial impressions.

PubMed

Swider, Brian W; Barrick, Murray R; Harris, T Brad; Stoverink, Adam C

2011-11-01

In employment interviews, individuals use impression management tactics to present themselves as suitable candidates to interviewers. However, not all impression management tactics, or the interviewees who employ them, are effective at positively influencing interview scores. Results of this study indicate that the relationship between impression management tactic usage and interview success is contingent on the type of tactic employed. Specifically, self-promotion was found to have a positive relationship (r = .20) and slight (r = -.11) and extensive (r = -.19) image creation were found to have negative relationships with end-of-interview scores. Further, the relationships between these 3 impression management tactics were moderated by interviewees' initial impressions of the interview (ΔR² ranged from .04 to .10). Interviewees who perceived they were seen as less suitable during rapport building were more effective when using any of the 3 impression management tactics. (c) 2011 APA, all rights reserved.

[Impression Formation in the Diagnosis and Treatment of Mental Disorders].

PubMed

Linden, Michael; Dymke, Tina; Hüttner, Susanne; Schnaubelt, Sabine

2016-06-01

The first item of any psychopathological assessment is "general impression". There is some research under the heading of "impression formation" which shows that the outer appearance of a person decides about how a person is perceived by others and how others react. Impression formation is an important factor in social interaction. This is of special importance in mental disorders, which may express themselves in a distorted impression formation. As impression formation is by and large an emotional process, measurement can be done by adjective lists. An example is the bipolar MED rating scale. Such lists can be used in therapy to help patients and therapists to understand the problem and initiate modifications. A special group intervention in occupational therapy is described. Results suggest that impression formation is quite objective, that self- and observer judgments coincide and that therapy can help to adopt a less irritating outer appearance. © Georg Thieme Verlag KG Stuttgart · New York.

A Simplified Technique for Implant-Abutment Level Impression after Soft Tissue Adaptation around Provisional Restoration

PubMed Central

Kutkut, Ahmad; Abu-Hammad, Osama; Frazer, Robert

2016-01-01

Impression techniques for implant restorations can be implant level or abutment level impressions with open tray or closed tray techniques. Conventional implant-abutment level impression techniques are predictable for maximizing esthetic outcomes. Restoration of the implant traditionally requires the use of the metal or plastic impression copings, analogs, and laboratory components. Simplifying the dental implant restoration by reducing armamentarium through incorporating conventional techniques used daily for crowns and bridges will allow more general dentists to restore implants in their practices. The demonstrated technique is useful when modifications to implant abutments are required to correct the angulation of malpositioned implants. This technique utilizes conventional crown and bridge impression techniques. As an added benefit, it reduces costs by utilizing techniques used daily for crowns and bridges. The aim of this report is to describe a simplified conventional impression technique for custom abutments and modified prefabricated solid abutments for definitive restorations. PMID:29563457

Using Aluminum Foil to Record Structures in Sedimentary Rock.

ERIC Educational Resources Information Center

Metz, Robert

1982-01-01

Aluminum foil can be used to make impressions of structures preserved in sedimentary rock. The impressions can be projected onto a screen, photographed, or a Plaster of Paris model can be made from them. Impressions of ripple marks, mudcracks, and raindrop impressions are provided in photographs illustrating the technique. (Author/JN)

Developing the Perfect Pitch: Creating a Positive First Impression through Social Media

ERIC Educational Resources Information Center

Edmiston, Dawn

2016-01-01

Too often we take for granted first impressions and how others perceive us, but such perceptions frequently form the basis for personal and professional success. Today, many first impressions are made online through search engine results and social networks. To ensure that students make a positive first impression, this teaching innovation…

Adaptation of zirconia crowns created by conventional versus optical impression: in vitro study

PubMed Central

Bahrami, Babak; Fossoyeux, InÈs; Atash, Ramin

2017-01-01

PURPOSE The aim of this study was to compare the precision of optical impression (Trios, 3Shape) versus that of conventional impression (Imprint IV, 3M-ESPE) with three different margins (shoulder, chamfer, and knife-edge) on Frasaco teeth. MATERIALS AND METHODS The sample comprised of 60 zirconia half-crowns, divided into six groups according to the type of impression and margin. Scanning electron microscopy enabled us to analyze the gap between the zirconia crowns and the Frasaco teeth, using ImageJ software, based on eight reproducible and standardized measuring points. RESULTS No statistically significant difference was found between conventional impressions and optical impressions, except for two of the eight points. A statistically significant difference was observed between the three margin types; the chamfer and knife-edge finishing lines appeared to offer better adaptation results than the shoulder margin. CONCLUSION Zirconia crowns created from optical impression and those created from conventional impression present similar adaptation. While offering identical results, the former have many advantages. In view of our findings, we believe the chamfer margin should be favored. PMID:28680553

Applying systems engineering to implement an evidence-based intervention at a community health center.

PubMed

Tu, Shin-Ping; Feng, Sherry; Storch, Richard; Yip, Mei-Po; Sohng, HeeYon; Fu, Mingang; Chun, Alan

2012-11-01

Impressive results in patient care and cost reduction have increased the demand for systems-engineering methodologies in large health care systems. This Report from the Field describes the feasibility of applying systems-engineering techniques at a community health center currently lacking the dedicated expertise and resources to perform these activities.

The Impact of Team Identification on Biased Predictions of Player Performance

ERIC Educational Resources Information Center

Wann, Daniel L.; Koch, Katrina; Knoth, Tasha; Fox, David; Aljubaily, Hesham; Lantz, Christopher D.

2006-01-01

The current investigation examined sport fans' impressions of an athlete described as a potential member of their team or a potential member of a rival team. In Study 1, we predicted that individuals would exhibit an ingroup favoritism effect by reporting more positive evaluations of the player's performance when he was described as a…

Applying Systems Engineering to Implement an Evidence-based Intervention at a Community Health Center

PubMed Central

Tu, Shin-Ping; Feng, Sherry; Storch, Richard; Yip, Mei-Po; Sohng, HeeYon; Fu, Mingang; Chun, Alan

2013-01-01

Summary Impressive results in patient care and cost reduction have increased the demand for systems-engineering methodologies in large health care systems. This Report from the Field describes the feasibility of applying systems-engineering techniques at a community health center currently lacking the dedicated expertise and resources to perform these activities. PMID:23698657

Organizational Behavior.

DTIC Science & Technology

1984-08-01

researchers and theoreticians are currently located in American business schools . Impressive theoretical and practical contributions have also come from...industry, the tension in business schools between 03 and * other business disciplines can be felt. Marketers, Finance/Accountants, * Management Scientists... business schools . it will be argued that this tension might be somewhat alleviated if OB researchers paid more attention to the economic benefits of 03

Monarchs (Danaus plexippus) and milkweeds (Asclepias species): The current situation and methods for propagating milkweeds

Treesearch

Tara Luna; R. Kasten Dumroese

2013-01-01

An international effort is under way to conserve populations of the monarch butterfly (Danaus plexippus L. [Lepidoptera: Nymphalidae]). Monarchs complete an impressive migration each year, flying from winter roosts on the California coast and the central mountains of Mexico to breeding areas throughout North America. Monarchs depend on habitats along their migratory...

Every Child, Every Classroom, Every Day: School Leaders Who Are Making Equity a Reality

ERIC Educational Resources Information Center

Peterkin, Robert; Jewell-Sherman, Deborah; Kelley, Laura; Boozer, Leslie

2011-01-01

This book demonstrates through case studies and expert analyses the impressive educational gains children can make when the best educational research, policy, and practice are aligned. This volume is a valuable resource to aspiring leaders, educational researchers, and current practitioners and a must-read for anyone who cares about the public…

Indianapolis Mayor Bart Peterson: The Peyton Manning of Charter Schools

ERIC Educational Resources Information Center

Skinner, David

2007-01-01

Indianapolis Mayor Bart Peterson has laid down a bold challenge to the city's troubled public school system: improve or see your students migrate to the city's growing roster of impressive charter schools. This is no idle threat. In the 2006-2007 academic year, the mayor oversaw 16 charter schools serving 3,870 students. Peterson is currently the…

Deconstructing the "I" and "SLA" in ISLA: One Curricular Approach

ERIC Educational Resources Information Center

Leow, Ronald P.; Cerezo, Luis

2016-01-01

Instructed second language acquisition (ISLA) has been referenced in the larger field of the SLA literature for over two and a half decades. Currently, there are several theoretical underpinnings accounting for processes assumed to play a role in ISLA and quite an impressive number of studies have empirically addressed some aspect(s) of ISLA.…

The Association between County-Level IQ and County-Level Crime Rates

ERIC Educational Resources Information Center

Beaver, Kevin M.; Wright, John Paul

2011-01-01

An impressive body of research has revealed that individual-level IQ scores are negatively associated with criminal and delinquent involvement. Recently, this line of research has been extended to show that state-level IQ scores are associated with state-level crime rates. The current study uses this literature as a springboard to examine the…

What Should Be in the Biology Curriculum?

ERIC Educational Resources Information Center

Leyser, Ottoline

2014-01-01

The ever-increasing amount of biological knowledge has resulted in compression of topics in the curriculum to a précis of current understanding. This gives the impression that biology is about a list of things we know. This misconception is extremely damaging, contributing to the idea that science is an impersonal process that generates facts,…

Accuracy of 3 different impression techniques for internal connection angulated implants.

PubMed

Tsagkalidis, George; Tortopidis, Dimitrios; Mpikos, Pavlos; Kaisarlis, George; Koidis, Petros

2015-10-01

Making implant impressions with different angulations requires a more precise and time-consuming impression technique. The purpose of this in vitro study was to compare the accuracy of nonsplinted, splinted, and snap-fit impression techniques of internal connection implants with different angulations. An experimental device was used to allow a clinical simulation of impression making by means of open and closed tray techniques. Three different impression techniques (nonsplinted, acrylic-resin splinted, and indirect snap-fit) for 6 internal-connected implants at different angulations (0, 15, 25 degrees) were examined using polyether. Impression accuracy was evaluated by measuring the differences in 3-dimensional (3D) position deviations between the implant body/impression coping before the impression procedure and the coping/laboratory analog positioned within the impression, using a coordinate measuring machine. Data were analyzed by 2-way ANOVA. Means were compared with the least significant difference criterion at P<.05. Results showed that at 25 degrees of implant angulation, the highest accuracy was obtained with the splinted technique (mean ±SE: 0.39 ±0.05 mm) and the lowest with the snap-fit technique (0.85 ±0.09 mm); at 15 degrees of angulation, there were no significant differences among splinted (0.22 ±0.04 mm) and nonsplinted technique (0.15 ±0.02 mm) and the lowest accuracy obtained with the snap-fit technique (0.95 ±0.15 mm); and no significant differences were found between nonsplinted and splinted technique at 0 degrees of implant placement. Splinted impression technique exhibited a higher accuracy than the other techniques studied when increased implant angulations at 25 degrees were involved. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Accuracy of Referring Provider and Endoscopist Impressions of Colonoscopy Indication.

PubMed

Naveed, Mariam; Clary, Meredith; Ahn, Chul; Kubiliun, Nisa; Agrawal, Deepak; Cryer, Byron; Murphy, Caitlin; Singal, Amit G

2017-07-01

Background: Referring provider and endoscopist impressions of colonoscopy indication are used for clinical care, reimbursement, and quality reporting decisions; however, the accuracy of these impressions is unknown. This study assessed the sensitivity, specificity, positive and negative predictive value, and overall accuracy of methods to classify colonoscopy indication, including referring provider impression, endoscopist impression, and administrative algorithm compared with gold standard chart review. Methods: We randomly sampled 400 patients undergoing a colonoscopy at a Veterans Affairs health system between January 2010 and December 2010. Referring provider and endoscopist impressions of colonoscopy indication were compared with gold-standard chart review. Indications were classified into 4 mutually exclusive categories: diagnostic, surveillance, high-risk screening, or average-risk screening. Results: Of 400 colonoscopies, 26% were performed for average-risk screening, 7% for high-risk screening, 26% for surveillance, and 41% for diagnostic indications. Accuracy of referring provider and endoscopist impressions of colonoscopy indication were 87% and 84%, respectively, which were significantly higher than that of the administrative algorithm (45%; P <.001 for both). There was substantial agreement between endoscopist and referring provider impressions (κ=0.76). All 3 methods showed high sensitivity (>90%) for determining screening (vs nonscreening) indication, but specificity of the administrative algorithm was lower (40.3%) compared with referring provider (93.7%) and endoscopist (84.0%) impressions. Accuracy of endoscopist, but not referring provider, impression was lower in patients with a family history of colon cancer than in those without (65% vs 84%; P =.001). Conclusions: Referring provider and endoscopist impressions of colonoscopy indication are both accurate and may be useful data to incorporate into algorithms classifying colonoscopy indication. Copyright © 2017 by the National Comprehensive Cancer Network.

Randomized controlled clinical trial on the three-dimensional accuracy of fast-set impression materials.

PubMed

Rudolph, Heike; Quaas, Sebastian; Haim, Manuela; Preißler, Jörg; Walter, Michael H; Koch, Rainer; Luthardt, Ralph G

2013-06-01

The use of fast-setting impression materials with different viscosities for the one-stage impression technique demands precise working times when mixing. We examined the effect of varying working time on impression precision in a randomized clinical trial. Focusing on tooth 46, three impressions were made from each of 96 volunteers, using either a polyether (PE: Impregum Penta H/L DuoSoft Quick, 3 M ESPE) or an addition-curing silicone (AS: Aquasil Ultra LV, Dentsply/DeTrey), one with the manufacturer's recommended working time (used as a reference) and two with altered working times. All stages of the impression-taking were subject to randomization. The three-dimensional precision of the non-standard working time impressions was digitally analyzed compared to the reference impression. Statistical analysis was performed using multivariate models. The mean difference in the position of the lower right first molar (vs. the reference impression) ranged from ±12 μm for PE to +19 and -14 μm for AS. Significantly higher mean values (+62 to -40 μm) were found for AS compared to PE (+21 to -26 μm) in the area of the distal adjacent tooth. Fast-set impression materials offer high precision when used for single tooth restorations as part of a one-stage impression technique, even when the working time (mixing plus application of the light- and heavy-body components) diverges significantly from the manufacturer's recommended protocol. Best accuracy was achieved with machine-mixed heavy-body/light-body polyether. Both materials examined met the clinical requirements regarding precision when the teeth were completely syringed with light material.

A comparison of the accuracy of polyether, polyvinyl siloxane, and plaster impressions for long-span implant-supported prostheses.

PubMed

Hoods-Moonsammy, Vyonne J; Owen, Peter; Howes, Dale G

2014-01-01

The purpose of this study was to compare the capacity of different impression materials to accurately reproduce the positions of five implant analogs on a master model by comparing the resulting cast with the stainless steel master model. The study was motivated by the knowledge that distortions can occur during impression making and the pouring of casts and that this distortion may produce inaccuracies of subsequent restorations, especially long-span castings for implant superstructures. The master model was a stainless steel model with five implant analogs. The impression materials used were impression plaster (Plastogum, Harry J Bosworth), a polyether (Impregum Penta, 3M ESPE), and two polyvinyl siloxane (PVS) materials (Aquasil Monophase and Aquasil putty with light-body wash, Dentsply). Five impressions were made with each impression material and cast in die stone under strictly controlled laboratory conditions. The positions of the implants on the master model, the impression copings, and the implant analogs in the subsequent casts were measured using a coordinate measuring machine that measures within 4 μm of accuracy. Statistical analyses indicated that distortion occurred in all of the impression materials, but inconsistently. The PVS monophase material reproduced the master model most accurately. Although there was no significant distortion between the impressions and the master model or between the impressions and their casts, there were distortions between the master model and the master casts, which highlighted the cumulative effects of the distortions. The polyether material proved to be the most reliable in terms of predictability. The impression plaster displayed cumulative distortion, and the PVS putty with light body showed the least reliability. Some of the distortions observed are of clinical significance and likely to contribute to a lack of passive fit of any superstructure. The inaccuracy of these analog materials and procedures suggested that greater predictability may lie in digital technology.

Effects on humans elicited by inhaling the fragrance of essential oils: sensory test, multi-channel thermometric study and forehead surface potential wave measurement on basil and peppermint.

PubMed

Satoh, Tomoko; Sugawara, Yoshiaki

2003-01-01

The effects on humans inhaling the fragrance of essential oils were examined in terms of a sensory test, a multi-channel skin thermometer study and a portable forehead surface electroencephalographic (IBVA-EEG) measurement. The essential oils examined in this study were those of basil and peppermint, because our previous sensory test had indicated an opposite effect of these essential oils when mental work was undertaken; the inhalation of basil produced a more favorable impression after work than before work, whereas peppermint produced an unfavorable impression under these circumstances. For subjects administered basil or peppermint before and after mental work using an inhalator, a series of multi-channel skin thermometer studies and IBVA-EEG measurements were conducted. Using such paired odorants, our results showed that when compared between before and after mental work assigned to subjects: (1) the inhalation of basil, in which a favorable impression was predominant on the whole in terms of the sensory evaluation spectrum, was shown to be associated upward tendency in finger-tip skin temperature; (2) whereas these situations were opposite in the case of peppermint, in which the reversed (unfavorable) feature in sensory profiling was accompanied by a decrease in the magnitude of beta waves and a decrease in the finger-tip skin temperature both based on Welch's method, even at p < 0.01, implying a decreasing propensity of the aroused state and of the arousal response. The elucidation of such sensory and physiological endpoints of paired odorants would be of primary importance for human chemoreception science, because these are only rarely recorded during the same experiments, and this paradigm is highly informative about non-verbal responses to odorants.

Specific entities affecting the craniocervical region: osteogenesis imperfecta and related osteochondrodysplasias: medical and surgical management of basilar impression.

PubMed

Menezes, Arnold H

2008-10-01

Osteogenesis imperfecta (OI) is an inheritable disorder of bone development caused by defective collagen synthesis. The attendant basilar impression or secondary basilar invagination is uncommon but can be devastating. Fifty-two patients with osteochondrodysplasia (28 with OI, six with Hajdu-Cheney syndrome, six with Paget's disease, and 12 with spondyloepiphyseal dysplasia) with basilar impression were evaluated between 1985 and 2005. The male/female ratio in this cohort was 1:1. The mean age at presentation was 12.2 years. Symptoms and signs included headache, lower cranial nerve dysfunction, dysphagia, respiratory embarrassment, weakness, and ataxia. In the earlier part of the series (1985-1995), all patients with hydrocephalus were shunted and a ventral transoral decompression made for ventral compression of the pontomedullary junction followed by a dorsal occipitocervical fusion. As a result of this evaluation, it was felt that most patients would benefit by early bracing after the hydrocephalus was shunted if it existed. However, 20% of patients still required an anterior ventral decompression and the occipitocervical fusion. The results showed that the fusions were stable but over a period of time, there was progressive forward bending with osteogenesis imperfecta as well as with the Hajdu-Cheney syndrome. All patients with spondyloepiphyseal dysplasia had a good strong stable fusion which stood the test of time. In conclusion, we feel that early intervention with occipitocervical bracing can prevent the progressive march of significant basilar impression which leads to mortality.

Gender Bias in Initial Perceptions and Subsequent Hiring Decisions.

ERIC Educational Resources Information Center

Morris, Scott B.; And Others

Much of the research on sex bias looks at impressions at a single point in time. However, impressions are often changed as information is accumulated. This study attempted to look at the dynamic nature of impression formation. Impressions of both male and female job applicants were measured before and after subjects had an opportunity to view…

Making an implant-level impression using solid plastic, press-fit, closed-tray impression copings: a clinical report.

PubMed

Selecman, Audrey M; Wicks, Russell A

2009-03-01

An implant-level impression is often desired for designing and fabricating an implant-supported fixed restoration, especially when 2 or more implants have been placed. However, convergent implants placed too close in proximity pose several problems, starting with the impression. In situations of extreme convergence or close proximity, modification of conventional metal copings may be impossible. This clinical report describes the use and associated advantages and disadvantages of solid plastic, press-fit, closed-tray impression copings as a mechanism suitable to create an implant-level cast.

Modification of Fixture Mount to be Used as an Impression Coping in Closely Placed Implants

PubMed Central

Jain, Anoop; K, Cauvery; Kumar, Pawan; Havale, Raghavendra

2014-01-01

An implant-level impression is often desired for designing and fabricating an implant-supported fixed restoration. This clinical report describes the use of modified press-fit metal implant fixture mount as an impression coping for making an impression of closely placed implants. The fixture mount is easier to manipulate, time saving and more comfortable for both the clinician and patient because the implant fixture mount is connected to the implant by pressing on instead of screwing. As compared to plastic press fit impression coping, metal fixture mount will not distort when modification of fixture mount are required in convergently or closely placed implants. It has the advantage of both the open-tray and closed-tray implant impression techniques. PMID:24959520

Modification of Fixture Mount to be Used as an Impression Coping in Closely Placed Implants.

PubMed

Mahoorkar, Sudhindra; Jain, Anoop; K, Cauvery; Kumar, Pawan; Havale, Raghavendra

2014-04-01

An implant-level impression is often desired for designing and fabricating an implant-supported fixed restoration. This clinical report describes the use of modified press-fit metal implant fixture mount as an impression coping for making an impression of closely placed implants. The fixture mount is easier to manipulate, time saving and more comfortable for both the clinician and patient because the implant fixture mount is connected to the implant by pressing on instead of screwing. As compared to plastic press fit impression coping, metal fixture mount will not distort when modification of fixture mount are required in convergently or closely placed implants. It has the advantage of both the open-tray and closed-tray implant impression techniques.

Contour of lingual surface in lower complete denture formed by polished surface impression.

PubMed

Heo, Yu-Ri; Kim, Hee-Jung; Son, Mee-Kyoung; Chung, Chae-Heon

2016-12-01

The aim of this study was to analyze the shapes of lingual polished surfaces in lower complete dentures formed by polished surface impressions and to provide reference data for use when manufacturing edentulous trays and lower complete dentures. Twenty-six patients with mandibular edentulism were studied. After lower wax dentures were fabricated, wax was removed from the lingual side of the wax denture and a lingual polished surface impression was obtained with tissue conditioner. The definitive denture was scanned with a three-dimensional scanner, and scanned images were obtained. At the cross-sections of the lingual frenum, lateral incisors, first premolars, first molars, and anterior border of the retromolar pads, three points were marked and eight measurements were taken. The Kruskal-Wallis test and a post hoc analysis with the Mann-Whitney test were performed. Each patient showed similar values for the same areas on the left and right sides without a statistically significant difference. The height of the contour of the lingual polished surface at the lingual frenum was halfway between the occlusal plane and lingual border, it moved gradually in a downward direction. The angle from the occlusal plane to the height of the contour of the lingual polished surface was increased as it progressed from the lingual frenum towards the retromolar pads. The shape of the mandibular lingual polished surface was convex at the lingual frenum, lateral incisors and gradually flattened towards the first molars and retromolar pads.

An Improved Algorithm of Congruent Matching Cells (CMC) Method for Firearm Evidence Identifications

PubMed Central

Tong, Mingsi; Song, John; Chu, Wei

2015-01-01

The Congruent Matching Cells (CMC) method was invented at the National Institute of Standards and Technology (NIST) for firearm evidence identifications. The CMC method divides the measured image of a surface area, such as a breech face impression from a fired cartridge case, into small correlation cells and uses four identification parameters to identify correlated cell pairs originating from the same firearm. The CMC method was validated by identification tests using both 3D topography images and optical images captured from breech face impressions of 40 cartridge cases fired from a pistol with 10 consecutively manufactured slides. In this paper, we discuss the processing of the cell correlations and propose an improved algorithm of the CMC method which takes advantage of the cell correlations at a common initial phase angle and combines the forward and backward correlations to improve the identification capability. The improved algorithm is tested by 780 pairwise correlations using the same optical images and 3D topography images as the initial validation. PMID:26958441

An Improved Algorithm of Congruent Matching Cells (CMC) Method for Firearm Evidence Identifications.

PubMed

Tong, Mingsi; Song, John; Chu, Wei

2015-01-01

The Congruent Matching Cells (CMC) method was invented at the National Institute of Standards and Technology (NIST) for firearm evidence identifications. The CMC method divides the measured image of a surface area, such as a breech face impression from a fired cartridge case, into small correlation cells and uses four identification parameters to identify correlated cell pairs originating from the same firearm. The CMC method was validated by identification tests using both 3D topography images and optical images captured from breech face impressions of 40 cartridge cases fired from a pistol with 10 consecutively manufactured slides. In this paper, we discuss the processing of the cell correlations and propose an improved algorithm of the CMC method which takes advantage of the cell correlations at a common initial phase angle and combines the forward and backward correlations to improve the identification capability. The improved algorithm is tested by 780 pairwise correlations using the same optical images and 3D topography images as the initial validation.

The influence of storage duration on the setting time of type 1 alginate impression material

NASA Astrophysics Data System (ADS)

Rahmadina, A.; Triaminingsih, S.; Irawan, B.

2017-08-01

Alginate is one of the most commonly used dental impression materials; however, its setting time is subject to change depending on storage conditions and duration. This creates problems because consumer carelessness can affect alginate shelf life and quality. In the present study, the setting times of two groups of type I alginate with different expiry dates was tested. The first group consisted of 11 alginate specimens that had not yet passed the expiry date, and the second group consisted of alginates that had passed the expiry date. The alginate powder was mixed with distilled water, poured into a metal ring, and tested with a polished rod of poly-methyl methacrylate. Statistical analysis showed a significant difference (p<0.05) between the setting times of the alginate that had not passed the expiry date (157 ± 3 seconds) and alginate that had passed the expiry date (144 ± 2 seconds). These findings indicate that storage duration can affect alginate setting time.

Production and evaluation of stereoscopic video presentation in surgical training

NASA Astrophysics Data System (ADS)

Ilgner, Justus; Kawai, Takashi; Westhofen, Martin; Shibata, Takashi

2004-05-01

Stereoscopic video teaching can facilitate understanding for current minimally-invasive operative techniques. This project was created to set up a digital stereoscopic teaching environment for training of ENT residents and medical students. We recorded three ENT operative procedures (tympanoplasty, paranasal sinus operation and laser chordectomy) at the University Hospital Aachen. The material was edited stereoscopically at the Waseda University and converted into a streaming 3-D video format, which does not depend on PAL or NTSC signal standards. Video clips were evaluated by 5 ENT specialists and 11 residents in single sessions on an LCD monitor (8) and a CRT monitor (8). Emphasis was laid on depth perception, visual fatigue and time to achieve stereoscopic impression. Qualitative results were recorded on a visual analogue scale, ranging from 1 (excellent) to 5 (bad). The overall impression was rated 2,06 to 3,13 in the LCD group and 2,0 to 2,62 in the CRT group. The depth impression was rated 1,63 to 2,88 (LCD) and 1,63 to 2,25 (CRT). Stereoscopic video teaching was regarded as useful in ENT training by all participants. Further points for evaluation will be the quantification of depth information as well as the information gain in teaching junior colleagues.

TePtFe Nanotubes as High-Performing Bifunctional Electrocatalysts for the Oxygen Reduction Reaction and Hydrogen Evolution Reaction.

PubMed

Li, Wenqiang; Amiinu, Ibrahim Saana; Ye, Bei; Wang, Zhe; Zhu, Jiawei; Kou, Zongkui; Mu, Shichun

2018-04-25

Currently, a multicomponent platinum-based alloy has been applied as a promising electrocatalyst to improve catalysis and lower the usage of the noble metal platinum. Herein, a tellurium nanowire (NW)-derived ternary TePtFe nanotube (NT) electrocatalyst has been prepared by the Kirkendall effect. The TePtFe NT formed consists of small single-crystal nanoparticles and voids with an open-end and hollow structure. The TePtFe NT electrocatalyst presents an impressive catalytic activity and stability for both the oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER). Its ORR specific activity and mass activity are 8.5 and 2.4 times, respectively, improved relative to those of commercial platinum catalysts. It is also impressive that, for the HER, a very low overpotential of 28.1 mV at 10 mA cm -2 can be achieved; this is lower than that of platinum (51.8 mV) catalysts in 0.1 m HClO 4 , and the activity is improved, even after 5000 cycles. This work reveals that TePtFe NTs can be employed as nanocatalysts with an impressive catalytic activity and stability for application in fuel cells and hydrogen production. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

The unique contributions of perceiver and target characteristics in person perception.

PubMed

Hehman, Eric; Sutherland, Clare A M; Flake, Jessica K; Slepian, Michael L

2017-10-01

Models of person perception have long asserted that our impressions of others are guided by characteristics of both the target and perceiver. However, research has not yet quantified to what extent perceivers and targets contribute to different impressions. This quantification is theoretically critical, as it addresses how much an impression arises from "our minds" versus "others' faces." Here, we apply cross-classified random effects models to address this fundamental question in social cognition, using approximately 700,000 ratings of faces. With this approach, we demonstrate that (a) different trait impressions have unique causal processes, meaning that some impressions are largely informed by perceiver-level characteristics whereas others are driven more by physical target-level characteristics; (b) modeling of perceiver- and target-variance in impressions informs fundamental models of social perception; (c) Perceiver × Target interactions explain a substantial portion of variance in impressions; (d) greater emotional intensity in stimuli decreases the influence of the perceiver; and (e) more variable, naturalistic stimuli increases variation across perceivers. Important overarching patterns emerged. Broadly, traits and dimensions representing inferences of character (e.g., dominance) are driven more by perceiver characteristics than those representing appearance-based appraisals (e.g., youthful-attractiveness). Moreover, inferences made of more ambiguous traits (e.g., creative) or displays (e.g., faces with less extreme emotions, less-controlled stimuli) are similarly driven more by perceiver than target characteristics. Together, results highlight the large role that perceiver and target variability play in trait impressions, and develop a new topography of trait impressions that considers the source of the impression. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Does aging impair first impression accuracy? Differentiating emotion recognition from complex social inferences.

PubMed

Krendl, Anne C; Rule, Nicholas O; Ambady, Nalini

2014-09-01

Young adults can be surprisingly accurate at making inferences about people from their faces. Although these first impressions have important consequences for both the perceiver and the target, it remains an open question whether first impression accuracy is preserved with age. Specifically, could age differences in impressions toward others stem from age-related deficits in accurately detecting complex social cues? Research on aging and impression formation suggests that young and older adults show relative consensus in their first impressions, but it is unknown whether they differ in accuracy. It has been widely shown that aging disrupts emotion recognition accuracy, and that these impairments may predict deficits in other social judgments, such as detecting deceit. However, it is unclear whether general impression formation accuracy (e.g., emotion recognition accuracy, detecting complex social cues) relies on similar or distinct mechanisms. It is important to examine this question to evaluate how, if at all, aging might affect overall accuracy. Here, we examined whether aging impaired first impression accuracy in predicting real-world outcomes and categorizing social group membership. Specifically, we studied whether emotion recognition accuracy and age-related cognitive decline (which has been implicated in exacerbating deficits in emotion recognition) predict first impression accuracy. Our results revealed that emotion recognition accuracy did not predict first impression accuracy, nor did age-related cognitive decline impair it. These findings suggest that domains of social perception outside of emotion recognition may rely on mechanisms that are relatively unimpaired by aging. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Two- and three-dimensional accuracy of dental impression materials: effects of storage time and moisture contamination.

PubMed

Chandran, Deepa T; Jagger, Daryll C; Jagger, Robert G; Barbour, Michele E

2010-01-01

Dental impression materials are used to create an inverse replica of the dental hard and soft tissues, and are used in processes such as the fabrication of crowns and bridges. The accuracy and dimensional stability of impression materials are of paramount importance to the accuracy of fit of the resultant prosthesis. Conventional methods for assessing the dimensional stability of impression materials are two-dimensional (2D), and assess shrinkage or expansion between selected fixed points on the impression. In this study, dimensional changes in four impression materials were assessed using an established 2D and an experimental three-dimensional (3D) technique. The former involved measurement of the distance between reference points on the impression; the latter a contact scanning method for producing a computer map of the impression surface showing localised expansion, contraction and warpage. Dimensional changes were assessed as a function of storage times and moisture contamination comparable to that found in clinical situations. It was evident that dimensional changes observed using the 3D technique were not always apparent using the 2D technique, and that the former offers certain advantages in terms of assessing dimensional accuracy and predictability of impression methods. There are, however, drawbacks associated with 3D techniques such as the more time-consuming nature of the data acquisition and difficulty in statistically analysing the data.

The relationship between digital model accuracy and time-dependent deformation of alginate impressions.

PubMed

Alcan, Toros; Ceylanoğlu, Cenk; Baysal, Bekir

2009-01-01

To investigate the effects of different storage periods of alginate impressions on digital model accuracy. A total of 105 impressions were taken from a master model with three different brands of alginates and were poured into stone models in five different storage periods. In all, 21 stone models were poured and immediately were scanned, and 21 digital models were prepared. The remaining 84 impressions were poured after 1, 2, 3, and 4 days, respectively. Five linear measurements were made by three researchers on the master model, the stone models, and the digital models. Time-dependent deformation of alginate impressions at different storage periods and the accuracy of traditional stone models and digital models were evaluated separately. Both the stone models and the digital models were highly correlated with the master model. Significant deformities in the alginate impressions were noted at different storage periods of 1 to 4 days. Alginate impressions of different brands also showed significant differences between each other on the first, third, and fourth days. Digital orthodontic models are as reliable as traditional stone models and probably will become the standard for orthodontic clinical use. Storing alginate impressions in sealed plastic bags for up to 4 days caused statistically significant deformation of alginate impressions, but the magnitude of these deformations did not appear to be clinically relevant and had no adverse effect on digital modeling.

Making a Positive Impression about the Mission of an Urban, Catholic University: Gender, First-Generation College, and Religious Preference Comparisons

ERIC Educational Resources Information Center

Ferrari, Joseph R.; Mader, Megan C.; Milner, Lauren A.; Temperato, John R.

2010-01-01

This study investigates how research participants' desire to make a positive social impression may affect their responses to survey questions. Specifically, participants may react in socially appropriate ways to create a positive social impression for those persons reviewing their responses. This concept is termed "impression management," or more…

No Second Chance to Make a First Impression: The "Thin-Slice" Effect on Instructor Ratings and Learning Outcomes in Higher Education

ERIC Educational Resources Information Center

Samudra, Preeti G.; Min, Inah; Cortina, Kai S.; Miller, Kevin F.

2016-01-01

Prior research has found strong and persistent effects of instructor first impressions on student evaluations. Because these studies look at real classroom lessons, this finding fits two different interpretations: (1) first impressions may color student experience of instruction regardless of lesson quality, or (2) first impressions may provide…

Social Relevance Enhances Memory for Impressions in Older Adults

PubMed Central

Cassidy, Brittany S.; Gutchess, Angela H.

2012-01-01

Previous research has demonstrated that older adults have difficulty retrieving contextual material over items alone. Recent research suggests this deficit can be reduced by adding emotional context, allowing for the possibility that memory for social impressions may show less age-related decline than memory for other types of contextual information. Two studies investigated how orienting to social or self-relevant aspects of information contributed to the learning and retrieval of impressions in young and older adults. Participants encoded impressions of others in conditions varying in the use of self-reference (Experiment 1) and interpersonal meaningfulness (Experiment 2), and completed memory tasks requiring the retrieval of specific traits. For both experiments, age groups remembered similar numbers of impressions. In Experiment 1, using more self-relevant encoding contexts increased memory for impressions over orienting to stimuli in a non-social way, regardless of age. In Experiment 2, older adults had enhanced memory for impressions presented in an interpersonally meaningful relative to a personally irrelevant way, whereas young adults were unaffected by this manipulation. The results provide evidence that increasing social relevance ameliorates age differences in memory for impressions, and enhances older adults’ ability to successfully retrieve contextual information. PMID:22364168

Semantic word impressions expressed by hue.

PubMed

Shinomori, Keizo; Komatsu, Honami

2018-04-01

We investigated the possibility of whether impressions of semantic words showing complex concepts could be stably expressed by hues. Using a paired comparison method, we asked ten subjects to select from a pair of hues the one that more suitably matched a word impression. We employed nine Japanese semantic words and used twelve hues from vivid tones in the practical color coordinate system. As examples of the results, for the word "vigorous" the most frequently selected color was yellow and the least selected was blue to purple; for "tranquil" the most selected was yellow to green and the least selected was red. Principal component analysis of the selection data indicated that the cumulative contribution rate of the first two components was 94.6%, and in the two-dimensional space of the components, all hues were distributed as a hue-circle shape. In addition, comparison with additional data of color impressions measured by a semantic differential method suggested that most semantic word impressions can be stably expressed by hue, but the impression of some words, such as "magnificent" cannot. These results suggest that semantic word impression can be expressed reasonably well by color, and that hues are treated as impressions from the hue circle, not from color categories.

Bragging on Facebook: The Interaction of Content Source and Focus in Online Impression Formation.

PubMed

Scott, Graham G; Ravenscroft, Kirsty

2017-01-01

Warranting Theory proposes that third-party testimonials are more influential in online impression formation than target-authored statements. Individuals posting content on social media accurately convey their offline personality while endeavoring to present themselves in a positive light. In doing so, they may misjudge the psychological distance of the majority of viewers, who could view this positive self-presentation as bragging and form resultant negative impressions. In this study, we asked 136 participants to view the Facebook timelines of four female targets. Timeline content varied by source (owner- vs. friend-authored) and focus (generally positive vs. personally positive). Participants were tasked with forming impressions of targets and rating them based on attractiveness, confidence, modesty, and popularity. We found that source and focus played distinct roles in impression formation. More positive impressions were formed when owner-authored content was general, and when friend-authored content was personal. This highlights the role played by content focus in impression formation, and the potentially damaging effect of perceived bragging. These results are discussed in relation to the application of the Warranting Theory of impression formation online, and discrepancies between these results and those from related articles are examined.

Facial first impressions and partner preference models: Comparable or distinct underlying structures?

PubMed

South Palomares, Jennifer K; Sutherland, Clare A M; Young, Andrew W

2017-12-17

Given the frequency of relationships nowadays initiated online, where impressions from face photographs may influence relationship initiation, it is important to understand how facial first impressions might be used in such contexts. We therefore examined the applicability of a leading model of verbally expressed partner preferences to impressions derived from real face images and investigated how the factor structure of first impressions based on potential partner preference-related traits might relate to a more general model of facial first impressions. Participants rated 1,000 everyday face photographs on 12 traits selected to represent (Fletcher, et al. 1999, Journal of Personality and Social Psychology, 76, 72) verbal model of partner preferences. Facial trait judgements showed an underlying structure that largely paralleled the tripartite structure of Fletcher et al.'s verbal preference model, regardless of either face gender or participant gender. Furthermore, there was close correspondence between the verbal partner preference model and a more general tripartite model of facial first impressions derived from a different literature (Sutherland et al., 2013, Cognition, 127, 105), suggesting an underlying correspondence between verbal conceptual models of romantic preferences and more general models of facial first impressions. © 2017 The British Psychological Society.

Accuracy of Digital Impressions and Fitness of Single Crowns Based on Digital Impressions

PubMed Central

Yang, Xin; Lv, Pin; Liu, Yihong; Si, Wenjie; Feng, Hailan

2015-01-01

In this study, the accuracy (precision and trueness) of digital impressions and the fitness of single crowns manufactured based on digital impressions were evaluated. #14-17 epoxy resin dentitions were made, while full-crown preparations of extracted natural teeth were embedded at #16. (1) To assess precision, deviations among repeated scan models made by intraoral scanner TRIOS and MHT and model scanner D700 and inEos were calculated through best-fit algorithm and three-dimensional (3D) comparison. Root mean square (RMS) and color-coded difference images were offered. (2) To assess trueness, micro computed tomography (micro-CT) was used to get the reference model (REF). Deviations between REF and repeated scan models (from (1)) were calculated. (3) To assess fitness, single crowns were manufactured based on TRIOS, MHT, D700 and inEos scan models. The adhesive gaps were evaluated under stereomicroscope after cross-sectioned. Digital impressions showed lower precision and better trueness. Except for MHT, the means of RMS for precision were lower than 10 μm. Digital impressions showed better internal fitness. Fitness of single crowns based on digital impressions was up to clinical standard. Digital impressions could be an alternative method for single crowns manufacturing. PMID:28793417

Forming impressions of facial attractiveness is mandatory.

PubMed

Ritchie, Kay L; Palermo, Romina; Rhodes, Gillian

2017-03-28

First impressions of social traits, such as attractiveness, from faces are often claimed to be made automatically, given their speed and reliability. However, speed of processing is only one aspect of automaticity. Here we address a further aspect, asking whether impression formation is mandatory. Mandatory formation requires that impressions are formed about social traits even when this is task-irrelevant, and that once formed, these impressions are difficult to inhibit. In two experiments, participants learned what new people looked like for the purpose of future identification, from sets of images high or low in attractiveness. They then rated middle-attractiveness images of each person, for attractiveness. Even though instructed to rate the specific images, not the people, their ratings were biased by the attractiveness of the learned images. A third control experiment, with participants rating names, demonstrated that participants in Experiments 1 and 2 were not simply rating the people, rather than the specific images as instructed. These results show that the formation of attractiveness impressions from faces is mandatory, thus broadening the evidence for automaticity of facial impressions. The mandatory formation of impressions is likely to have an important impact in real-world situations such as online dating sites.

Social relevance enhances memory for impressions in older adults.

PubMed

Cassidy, Brittany S; Gutchess, Angela H

2012-01-01

Previous research has demonstrated that older adults have difficulty retrieving contextual material over items alone. Recent research suggests this deficit can be reduced by adding emotional context, allowing for the possibility that memory for social impressions may show less age-related decline than memory for other types of contextual information. Two studies investigated how orienting to social or self-relevant aspects of information contributed to the learning and retrieval of impressions in young and older adults. Participants encoded impressions of others in conditions varying in the use of self-reference (Experiment 1) and interpersonal meaningfulness (Experiment 2), and completed memory tasks requiring the retrieval of specific traits. For both experiments, age groups remembered similar numbers of impressions. In Experiment 1 using more self-relevant encoding contexts increased memory for impressions over orienting to stimuli in a non-social way, regardless of age. In Experiment 2 older adults had enhanced memory for impressions presented in an interpersonally meaningful relative to a personally irrelevant way, whereas young adults were unaffected by this manipulation. The results provide evidence that increasing social relevance ameliorates age differences in memory for impressions, and enhances older adults' ability to successfully retrieve contextual information.

Performance of dental impression materials: Benchmarking of materials and techniques by three-dimensional analysis.

PubMed

Rudolph, Heike; Graf, Michael R S; Kuhn, Katharina; Rupf-Köhler, Stephanie; Eirich, Alfred; Edelmann, Cornelia; Quaas, Sebastian; Luthardt, Ralph G

2015-01-01

Among other factors, the precision of dental impressions is an important and determining factor for the fit of dental restorations. The aim of this study was to examine the three-dimensional (3D) precision of gypsum dies made using a range of impression techniques and materials. Ten impressions of a steel canine were fabricated for each of the 24 material-method-combinations and poured with type 4 die stone. The dies were optically digitized, aligned to the CAD model of the steel canine, and 3D differences were calculated. The results were statistically analyzed using one-way analysis of variance. Depending on material and impression technique, the mean values had a range between +10.9/-10.0 µm (SD 2.8/2.3) and +16.5/-23.5 µm (SD 11.8/18.8). Qualitative analysis using colorcoded graphs showed a characteristic location of deviations for different impression techniques. Three-dimensional analysis provided a comprehensive picture of the achievable precision. Processing aspects and impression technique were of significant influence.

The use of impression management tactics in structured interviews: a function of question type?

PubMed

Ellis, Aleksander P J; West, Bradley J; Ryan, Ann Marie; DeShon, Richard P

2002-12-01

This study investigated impression management tactic use during structured interviews containing both experience-based and situational questions. Specifically, the authors examined whether applicants' use of impression management tactics depended on question type. Results from 119 structured interviews indicated that almost all of the applicants used some form of impression management. Significantly more assertive than defensive impression management tactics were used, and among assertive tactics, applicants tended to use self-promotion rather than ingratiation. However, different question types prompted the use of different impression management tactics. Ingratiation tactics were used significantly more when applicants answered situational questions, whereas self-promotion tactics were used significantly more when applicants answered experience-based questions. Furthermore, the use of self-promotion and ingratiation tactics was positively related to interviewer evaluations.

Forming first impressions of children: the role of attention-deficit/hyperactivity disorder symptoms and emotion dysregulation.

PubMed

Lee, Christine A; Milich, Richard; Lorch, Elizabeth P; Flory, Kate; Owens, Julie Sarno; Lamont, Andrea E; Evans, Steven W

2018-05-01

Previous research on peer status of children with attention-deficit/hyperactivity disorder (ADHD) has focused on already-established peer groups, rendering the specific social behaviors that influence peers' initial impressions largely unknown. Recently, theorists have argued that emotion dysregulation is a key aspect of ADHD, with empirical work finding relations between emotion dysregulation and social outcomes. Therefore, the current study focuses on the initial interactions among children varying in ADHD symptoms duringh a novel playgroup, proposing that emotion dysregulation displayed during the playgroup may serve as a possible pathway between ADHD symptoms and peers' initial negative impressions. Participants were 233 elementary-age children ranging from 8 to 10 years old (M = 8.83, 70% male). Parents and teachers rated children's ADHD symptoms and related impairment; 51% of the children met criteria for an ADHD diagnosis. Then, children participated with unfamiliar peers in a three-hour playgroup that included three structured and two unstructured tasks. After the tasks, children and staff rated each child on social outcomes. Coders unaware of child's diagnostic status watched videos of the groups and rated each child's global emotion dysregulation during each task. Using multiple raters and methods, ADHD severity was associated with more negative peer ratings, through observed emotion dysregulation. Results were consistent for both parent and teacher ratings of ADHD severity as well as for both peer ratings of likeability and staff ratings of perceived peer likeability. When focusing on improving peers' initial impressions of children with ADHD symptoms, emotion dysregulation may be a valuable target for intervention. © 2017 Association for Child and Adolescent Mental Health.

The Fundamental Human Right to Education for Refugees: Some Legal Remarks

ERIC Educational Resources Information Center

Willems, Kurt; Vernimmen, Jonas

2018-01-01

The aim of this article is to describe the human rights obligations a State bears in educational matters with concerns to the current influx of refugees. The right to education is a fundamental human right guaranteed by many international treaties. As a result, the impression may arise that everyone, not only legal citizens but also all those…

Improved Ceramic Anodes for Corrosion Protection.

DTIC Science & Technology

1984-11-01

34 . 4 UNCLASSIFIED SECURITY CLASSIFICATION OF THIS PAGE(Whi Data Entered) BLOCK 20 (Continued) ferrite over niobium over Ni- Cr -AI-Y...plasma-sprayed lithium ferrite on a valve metal substrate. Donor doped and reduced solid sintered titanate compounds yielded electrically conductive...Traditionally. impressed current systems have used tion (CEGS) 2310. antides that are either inexpensive and very large (high silicon, chromium

The Impact of Perceptual, Economic, and Demographic Variables on Entrepreneurial Activity in Globally Diverse Ecosystems: Evidence from GEM Data

ERIC Educational Resources Information Center

Adams, Kenneth Raymond

2016-01-01

Leveraging a sample of more than 198,000 adult entrepreneurs, both currently involved in the startup of a business or formerly involved in business creation, this study investigates the perceptual, societal impression, economic, and demographic variables that are predictive with an individual's decision to engage in entrepreneurial activity.…

Noninvasive identification of bladder cancer with subsurface backscattered light

NASA Astrophysics Data System (ADS)

Bigio, Irving J.; Mourant, Judith R.; Boyer, James D.; Johnson, Tamara M.; Shimada, Tsutomu; Conn, Richard L.

1994-05-01

We have developed and are testing early prototypes of an optical biopsy system (OBS) for detection of cancer and other tissue pathologies. The OBS invokes a unique approach to optical diagnosis of tissue pathologies based on the elastic scattering properties, over a wide range of wavelengths, of the microscopic structure of the tissue. Absorption bands in the tissue also add useful complexity to the spectral data collected. The data acquisition and storage/display time with the OBS instrument is approximately 1 second. Thus, in addition to the reduced invasiveness of this technique compared with current state-of- the-art methods, the OBS offers the possibility of impressively faster diagnostic assessment. The OBS employs a small fiber-optic probe that is amendable to use with any endoscope, catheter or hypodermic, or to direct surface examination (e.g., as in skin cancer or cervical cancer). We report here specifically on its potential application in the detection of bladder cancer.

Activated RET and ROS: two new driver mutations in lung adenocarcinoma

PubMed Central

Bos, Marc; Gardizi, Masyar; Schildhaus, Hans-Ulrich; Buettner, Reinhard

2013-01-01

Rearrangements of ROS1 and RET have been recently described as new driver mutations in lung adenocarcinoma with a frequency of about 1% each. RET and ROS1 rearrangements both represent unique molecular subsets of lung adenocarcinoma with virtually no overlap with other known driver mutations described so far in lung adenocarcinoma. Specific clinicopathologic characteristics have been described and several multitargeted receptor kinase inhibitors have shown in vitro activity against NSCLC cells harbouring these genetic alterations. In addition, the MET/ALK/ROS inhibitor crizotinib has already shown impressive clinical activity in patients with advanced ROS1-positive lung cancer. Currently, several early proof of concept clinical trials are testing various kinase inhibitors in both molecular subsets of lung adenocarcinoma patients. Most probably, personalized treatment of these genetically defined new subsets of lung adenocarcinoma will be implemented in routine clinical care of lung cancer patients in the near future. PMID:25806222

Mechanical properties of the rust layer induced by impressed current method in reinforced mortar

DOE Office of Scientific and Technical Information (OSTI.GOV)

Care, S.; Nguyen, Q.T.; L'Hostis, V.

This paper describes the mechanical effects of rust layer formed in reinforced mortar through accelerated tests of corrosion. The morphological and physico-chemical properties (composition, structures) of the corrosion system were characterized at different stages by using optical microscope and scanning electron microscope coupled with energy dispersive spectroscopy. The corrosion pattern was mainly characterized by a rust layer confined at the interface between the steel and the mortar. Expansion coefficient of rust products was determined from the rust thickness and the Faraday's law. Furthermore, in order to understand the mechanical effects of corrosion on the damage of mortar, displacement field measurementsmore » were obtained by using digital image correlation. An analytical model (hollow cylinder subjected to inner and outer pressures) was used with a set of experimental data to deduce the time of cracking and the order of magnitude of the mechanical properties of the rust layer.« less

Analysis of geometric moments as features for firearm identification.

PubMed

Md Ghani, Nor Azura; Liong, Choong-Yeun; Jemain, Abdul Aziz

2010-05-20

The task of identifying firearms from forensic ballistics specimens is exacting in crime investigation since the last two decades. Every firearm, regardless of its size, make and model, has its own unique 'fingerprint'. These fingerprints transfer when a firearm is fired to the fired bullet and cartridge case. The components that are involved in producing these unique characteristics are the firing chamber, breech face, firing pin, ejector, extractor and the rifling of the barrel. These unique characteristics are the critical features in identifying firearms. It allows investigators to decide on which particular firearm that has fired the bullet. Traditionally the comparison of ballistic evidence has been a tedious and time-consuming process requiring highly skilled examiners. Therefore, the main objective of this study is the extraction and identification of suitable features from firing pin impression of cartridge case images for firearm recognition. Some previous studies have shown that firing pin impression of cartridge case is one of the most important characteristics used for identifying an individual firearm. In this study, data are gathered using 747 cartridge case images captured from five different pistols of type 9mm Parabellum Vektor SP1, made in South Africa. All the images of the cartridge cases are then segmented into three regions, forming three different set of images, i.e. firing pin impression image, centre of firing pin impression image and ring of firing pin impression image. Then geometric moments up to the sixth order were generated from each part of the images to form a set of numerical features. These 48 features were found to be significantly different using the MANOVA test. This high dimension of features is then reduced into only 11 significant features using correlation analysis. Classification results using cross-validation under discriminant analysis show that 96.7% of the images were classified correctly. These results demonstrate the value of geometric moments technique for producing a set of numerical features, based on which the identification of firearms are made.

Physician's first clinical impression of emergency department patients with nonspecific complaints is associated with morbidity and mortality.

PubMed

Beglinger, Bettina; Rohacek, Martin; Ackermann, Selina; Hertwig, Ralph; Karakoumis-Ilsemann, Julia; Boutellier, Susanne; Geigy, Nicolas; Nickel, Christian; Bingisser, Roland

2015-02-01

The association between the physician's first clinical impression of a patient with nonspecific complaints and morbidity and mortality is unknown. The aim was to evaluate the association of the physician's first clinical impression with acute morbidity and mortality. We conducted a prospective observational study with a 30-day follow-up. This study was performed at the emergency departments (EDs) of 1 secondary and 1 tertiary care hospital, from May 2007 to February 2011. The first clinical impression ("looking ill"), expressed on a numerical rating scale from 0 to 100, age, sex, and the Charlson Comorbidity Index (CCI) were evaluated. The association was determined between these variables and acute morbidity and mortality, together with receiver operating characteristics, and validity. Of 217,699 presentations to the ED, a total of 1278 adult nontrauma patients with nonspecific complaints were enrolled by a study team. No patient was lost to follow-up. A total of 84 (6.6%) patients died during follow-up, and 742 (58.0%) patients were classified as suffering from acute morbidity. The variable "looking ill" was significantly associated with mortality and morbidity (per 10 point increase, odds ratio 1.23, 95% confidence interval [CI] 1.12-1.34, P < 0.001, and odds ratio 1.19, 95% CI 1.14-1.24, P < 0.001, respectively). The combination of the variables "looking ill," "age," "male sex," and "CCI" resulted in the best prediction of these outcomes (mortality: area under the curve [AUC] 0.77, 95% CI 0.72-0.82; morbidity: AUC 0.68, 95% CI 0.65-0.71). The physician's first impression, with or without additional variables such as age, male sex, and CCI, was associated with morbidity and mortality. This might help in the decision to perform further diagnostic tests and to hospitalize ED patients.

Transcranial direct current stimulation on primary sensorimotor area has no effect in patients with drug-naïve restless legs syndrome: a proof-of-concept clinical trial.

PubMed

Koo, Yong Seo; Kim, Sung Min; Lee, Chany; Lee, Byeong Uk; Moon, Ye Ji; Cho, Yong Won; Im, Chang-Hwan; Choi, Jeong Woo; Kim, Kyung Hwan; Jung, Ki-Young

2015-02-01

To evaluate the efficacy of transcranial direct current stimulation (tDCS) in people with drug-naïve restless legs syndrome (RLS). A two-week, double-blind, randomized, sham-controlled trial was performed. Thirty-three females with RLS were recruited. Participants received five sessions of tDCS using cathodal, anodal or sham stimulation. They were assessed at baseline (T0), three days (T1) and 13 days (T2) after the end of tDCS. Primary outcomes included the International RLS Group Rating Scale (IRLS) and the Clinical Global Impressions-Improvement (CGI-I). Secondary outcomes included the Patient Global Impression scale, the Pittsburgh Sleep Quality Index, the Medical Outcome Study sleep subscales, and the Beck Depression Inventory. Objective neurophysiological changes were assessed using event-related desynchronization/synchronization (ERD/ERS) of electroencephalography. The changes in the IRLS scores, as well as the responder rate in the CGI-I scale, did not differ significantly among the groups. There was also no significant difference in any of the secondary outcome measures and ERD/ERS among the groups. Transcranial direct current stimulation with electrodes on the sensorimotor areas showed no significant effect in people with drug-naïve RLS. Copyright © 2014 Elsevier B.V. All rights reserved.

Accuracy of various impression materials and methods for two implant systems: An effect size study.

PubMed

Schmidt, Alexander; Häussling, Teresa; Rehmann, Peter; Schaaf, Heidrun; Wöstmann, Bernd

2018-04-01

An accurate impression is required for implant treatment. The aim of this in-vitro study was to determine the effect size of the impression material/method, implant system and implant angulation on impression transfer precision. An upper jaw model with three BEGO and three Straumann implants (angulations 0°, 15°, 20°) in the left and right maxilla was used as a reference model. One polyether (Impregum Penta) and two polyvinyl siloxanes (Flexitime Monophase/Aquasil Ultra Monophase) were examined with two impression techniques (open and closed tray). A total of 60 impressions were made. A coordinate measurement machine was used to measure the target variables for 3D-shift, implant axis inclination and implant axis rotation. All the data were subjected to a four-way ANOVA. The effect size (partial eta-squared [η 2 P ]) was reported. The impression material had a significant influence on the 3D shift and the implant axis inclination deviation (p-values=.000), and both factors had very large effect sizes (3D-shift [η 2 P ]=.599; implant axis inclination [η 2 P ]=.298). Impressions made with polyvinyl siloxane exhibited the highest transfer precision. When the angulation of the implants was larger, more deviations occurred for the implant axis rotational deviation. The implant systems and impression methods showed partially significant variations (p-values=.001-.639) but only very small effect sizes (η 2 P =.001-.031). The impression material had the greatest effect size on accuracy in terms of the 3D shift and the implant axis inclination. For multiunit restorations with disparallel implants, polyvinyl siloxane materials should be considered. In addition, the effect size of a multivariate investigation should be reported. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

A randomised controlled trial of complete denture impression materials.

PubMed

Hyde, T P; Craddock, H L; Gray, J C; Pavitt, S H; Hulme, C; Godfrey, M; Fernandez, C; Navarro-Coy, N; Dillon, S; Wright, J; Brown, S; Dukanovic, G; Brunton, P A

2014-08-01

There is continuing demand for non-implant prosthodontic treatment and yet there is a paucity of high quality Randomised Controlled Trial (RCT) evidence for best practice. The aim of this research was to provide evidence for best practice in prosthodontic impressions by comparing two impression materials in a double-blind, randomised, crossover, controlled, clinical trial. Eighty-five patients were recruited, using published eligibility criteria, to the trial at Leeds Dental Institute, UK. Each patient received two sets of dentures; made using either alginate or silicone impressions. Randomisations determined the order of assessment and order of impressions. The primary outcome was patient blinded preference for unadjusted dentures. Secondary outcomes were patient preference for the adjusted dentures, rating of comfort, stability and chewing efficiency, experience of each impression, and an OHIP-EDENT questionnaire. Seventy-eight (91.8%) patients completed the primary assessment. 53(67.9%) patients preferred dentures made from silicone impressions while 14(17.9%) preferred alginate impressions. 4(5.1%) patients found both dentures equally satisfactory and 7 (9.0%) found both equally unsatisfactory. There was a 50% difference in preference rates (in favour of silicone) (95%CI 32.7-67.3%, p<0.0001). There is significant evidence that dentures made from silicone impressions were preferred by patients. Given the strength of the clinical findings within this paper, dentists should consider choosing silicone rather than alginate as their material of choice for secondary impressions for complete dentures. ISRCTN 01528038. This article forms part of a project for which the author (TPH) won the Senior Clinical Unilever Hatton Award of the International Assocation for Dental Research, Capetown, South Africa, June 2014. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

The influence of sequence of impressions on children's anxiety and discomfort.

PubMed

Kaakko, Tarja; Horn, Michael T; Weinstein, Philip; Kaufman, Eliezer; Leggott, Penelope; Coldwell, Susan E

2003-01-01

Laboratory studies with adults and children have found lower pain reports when pain proceeds from high to low rather than from low to high. However, pediatric dentists often ease children into difficult procedures (from easiest to most difficult). This study investigated the influence of order during a clinical procedure that involved taking maxillary and mandibular alginate impressions. Subjects were 24 children aged 5 to 6 years (preoperational stage) and 24 children aged 9 to 10 years (concrete operational stage). Children were randomly assigned to either start with the mandibular (presumed to be easier) or start with the maxillary (presumed to be harder) impressions. Discomfort during the sequence of impressions was measured using the "Affective Facial Scale." A telephone interview was conducted 2 weeks later to evaluate the memory of discomfort. The results indicated that the older children who started with the mandibular (easier) impression and ended with the maxillary (more uncomfortable) impression reported significantly lower discomfort than older children who started with the maxillary impression and ended with the mandibular (Mann-Whitney U, Z = -2.08; P < .037). The same tendency was noted 2 weeks later on a telephone interview. By phone, 92% of the older children who started with the mandibular impression rated the sequence of impressions as "not at all bad," while only 58% of the older children who started with the maxillary impression rated the overall experience as "not at all bad" (chi2 = 3.56, P < .059). The younger children did not show any significant difference in their ratings of discomfort at either of the assessment periods. Consistent with clinical practice, this study observed that older children benefit from beginning an appointment with an easier procedure and working up to a more difficult one.

Babyfacedness, sex of face stimulus, and social context in face perception and person evaluation.

PubMed

Lee, Yu-Kang

2013-06-01

This research investigated whether the well-documented babyface stereotypical effects are moderated by sex of face stimuli and social context. 'Medical doctor' and 'political candidate' were selected as two social contexts which differ at the private/public level. An experiment was conducted with 245 adults (M age = 38.5 yr., SD = 8.6, range = 23 to 64). Babyface effects were stronger for the babyfaced female in the political context, but greater for the babyfaced male in the doctor-patient context. Babyfacedness could be a disadvantage to men in political contexts if political sophistication is judged by their facial characteristics. The results of overall impressions are similar to the patterns of the likeability rating. Individual differences (political sophistication and health consciousness) account for little variance in inference-making or impression formation. Implications of the current findings are discussed, as are directions for future research.

Rocket-Induced Magnetohydrodynamic Ejector: A Single-Stage-to-Orbit Advanced Propulsion Concept

NASA Technical Reports Server (NTRS)

Cole, John; Campbell, Jonathan; Robertson, Anthony

1995-01-01

During the atmospheric boost phase of a rocket trajectory, magnetohydrodynamic (MHD) principles can be utilized to augment the thrust by several hundred percent without the input of additional energy. The concept is an MHD implementation of a thermodynamic ejector. Some ejector history is described and some test data showing the impressive thrust augmentation capabilities of thermodynamic ejectors are provided. A momentum and energy balance is used to derive the equations to predict the MHD ejector performance. Results of these equations are compared with the test data and then applied to a specific performance example. The rocket-induced MHD ejector (RIME) engine is described and a status of the technology and availability of the engine components is provided. A top level vehicle sizing analysis is performed by scaling existing MHD designs to the required flight vehicle levels. The vehicle can achieve orbit using conservative technology. Modest improvements are suggested using recently developed technologies, such as superconducting magnets, which can improve predicted performance well beyond those expected for current single-stage-to-orbit (SSTO) designs.

Influence of Genetic Counseling Graduate Program Websites on Student Application Decisions.

PubMed

Ivan, Kristina M; Hassed, Susan; Darden, Alix G; Aston, Christopher E; Guy, Carrie

2017-12-01

This study investigated how genetic counseling educational program websites affect application decisions via an online survey sent to current students and recent graduates. Program leadership: directors, assistant directors, associate directors, were also surveyed to determine where their opinions coincided or differed from those reported by students and recent graduates. Chi square analysis and t-tests were used to determine significance of results. A two-sample t-test was used to compare factors students identified as important on a 5-point Likert scale with those identified by directors. Thematic analysis revealed three major themes students consider important for program websites: easy navigation, website content, and website impression. Directors were interested in how prospective students use their program website and what information they found most useful. Students indicated there were specific programs they chose not to apply to due to the difficulty of using the website for that program. Directors significantly underestimated how important information about application requirements was to students in making application decisions. The information reported herein will help individual genetic counseling graduate programs improve website functionality and retain interested applicants.

Tool for Taking Clay Impressions

NASA Technical Reports Server (NTRS)

Duncan, R. S.

1984-01-01

Clay impression of small parts taken with tool consisting of hollow tube closed at one end. Slots at other end admit part short distance into tube. Impression used to make silicone rubber mold for examination.

Implant Impression Techniques for the Edentulous Jaw: A Summary of Three Studies.

PubMed

Stimmelmayr, Michael; Beuer, Florian; Edelhoff, Daniel; Güth, Jan-Frederik

2016-02-01

Precise implant-supported restorations require accurate impressions. Transfer, pick-up, and splinted pick-up are commonly used techniques. Several in vitro studies have compared these impression techniques; however, all studies used mechanical evaluation methods. The purpose of this study was to compare the discrepancies of these impression techniques digitally in vitro and in vivo. Four dental implants were inserted in ten polymer mandibular models bilaterally in the regions of the first molars and canines. Three different impressions were made of each model and the models (original and stone casts) were scanned and digitized. Clinically, four implants were inserted in ten edentulous jaws; transfer and splinted pick-up impressions were made. With inspection software, discrepancies between the different impressions were calculated. The mean discrepancies in the in vitro study of the original polymer model to stone casts were 124 ± 34 μm for the transfer type, 116 ± 46 μm for the pick-up type, and 80 ± 25 μm for the splinted pick-up type, resulting in a mean discrepancy between the transfer and splinted pick-up type of 44 μm (124 - 80 μm). Clinically, the mean discrepancy between these two impression techniques was 280 μm. The differing results between the transfer and splinted pick-up techniques of in vitro and in vivo data showed the need for clinical data; however, splinted pick-up impressions seemed to produce the most precise results. © 2015 by the American College of Prosthodontists.

Evaluation of the Efficacy of Different Mixing Techniques and Disinfection on Microbial Colonization of Polyether Impression Materials: A Comparative Study.

PubMed

Singla, Youginder; Pachar, Renu B; Poriya, Sangeeta; Mishra, Aalok; Sharma, Rajni; Garg, Anshu

2018-03-01

This study aims to determine the role of mixing techniques of polyether impression materials and efficacy of disinfection on microbial colonization of these impression materials. Polyether impression material was mixed using two methods: First by hand mixing (group I) and second using an automixer (group II) with a total of 100 samples. Four microbial strains were studied, which included Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. After incubation, the bacterial colonies were counted, and then, disinfectant solution was applied. The effect of disinfection solution was evaluated for each specimen. The surface of polyether impression materials mixed with an automixer has less number of voids and overall a smoother surface as compared with the hand-mixed ones. On comparing the disinfection procedures, i.e., specimens without any disinfection and specimens after disinfection, statistically highly significant difference was seen between all the groups. We can conclude that impression mixing procedures are important in determining the surface characteristics of the impression and ultimately the colonization of bacteria and also determine the importance of disinfection on microbial colonization. This study emphasises the deleterious role of nosocomial infections and specific measures that should be taken regarding the prevention of such diseases. Dental impressions are proved to be a source of such infections and may lead to transmission of such diseases. Thus, proper measures should be taken right from the first step of impression taking to minimizing and preventing such kind of contaminations in clinical practice.

[The global impression technic in fixed dentures].

PubMed

Lamy, M; Mainjot, A

2001-01-01

The global impression technique allows to obtain in a single stage the impression of the abutment as well as their neighboring teeth. This technique often requires the placement of one or two retraction cords in the sulcus. The impression technique herein described is the double mix method. This method is based on the use of two elastomers with different viscosities, but from the same group thus allowing a simultaneous polymerization.

Evaluation of a reproduction technique for the study of the enamel composite/bracket base area.

PubMed

Wilner, F J; Oliver, R G

2000-09-01

The objective of the study was to evaluate a reproduction method that would enable the study of the enamel/ bracket/composite interface in vivo, and consisted of in vitro assessment of two different impression materials to compare reproduction of brackets bonded to extracted teeth followed by in vivo assessment of the superior material. In vitro standard edgewise brackets were bonded to two extracted teeth and impressions were taken using two different types of low viscosity silicone-based impression materials. A medium viscosity silicone impression material was used to support the original impression. Three impressions of both the gingival and occlusal aspect of the bracket base region were obtained using each of the impression materials. Replicas were then prepared for SEM viewing and these compared to SEMs of the real teeth for reproduction of detail. A 3-point Reproducibility Index was used to compare the SEM photographs of the comparable replicas. One impression material was clearly superior to the other and produced an acceptably accurate representation of the true clinical situation in three out of four samples. This material also performed well in the in vivo situation. The technique described is satisfactory for the production and analysis of SEM pictures of the enamel/composite/ bracket base interface in vivo.

Comparison of the effect of different medicaments on surface reproduction of two commercially available Polyvinyl Siloxane impression materials - An Invitro Study

PubMed Central

Singh, Rina; Singh, Jagjit; Singh, Ramanpreet; Nanda, Sonia

2013-01-01

Objective:To determine the effect of different retraction cord medicaments on surface detail reproduction of polyvinyl siloxane impression materials and compare this effect on any two brands of commercially available polyvinyl siloxane impression materials. Material and methods: Four stainless steel dies were made according to ADA specification no.19. Three dies were treated with aluminium chloride (5%), ferric sulphate (13.3%) and epinephrine (0.1%) while the fourth one was left untreated to serve as control. Two impression materials (Dentsply and 3M ESPE) were used. Results: All the three medicaments adversely affected the surface detail reproduction of both the brands of the polyvinyl siloxane impression materials. These effects were statistically significant as compared to untreated control. The impressions of 3M ESPE brand have shown better surface detail reproduction as compared to Dentsply impression material. Conclusion: Surface detail reproduction of the polyvinyl siloxane impression materials is adversely affected by the retraction cord medicaments. The presence of moisture or any traces of the medicaments should be removed from the tooth surface to provide a dry field for the correct reproduction of the surface detail of these materials. Key words:Polyvinyl Siloxane, retraction cord medicaments, surface detail reproduction. PMID:24455069

Correlations between the Hand Test Pathology score and Personality Assessment Inventory scales for pain clinic patients.

PubMed

George, J M; Wagner, E E

1995-06-01

Pearson correlations between the Hand Test Pathology (PATH) score and Personality Assessment Inventory scales produced a cluster of relationships characteristic of an antisocial orientation. Likewise, PATH significantly differentiated between a "P" (Pathology) group flagged by a high Negative Impression score on the inventory, and an "N" (Normal) group of 100 pain patients. It was suggested that the interpretive simplicity of Hand Test scores renders the scores amenable to further correlational studies involving the inventory.

The Impact on DoD of the Toxic Substances Control Act

DTIC Science & Technology

1980-06-01

reconcile a limit of 10 ppm in the gasoline area where there is a potential for 400,000 exposures while in the rubber industry the potential is only 150,000...that the Ames test and other mutagenic tests are predictive of tumor producing potential. Many of us in toxi - cology are not impressed with this...also be completely different; so much for generic toxi - cology and for the possibility that short term testing for mutagenic effects is predictive of

21 CFR 872.6570 - Impression tube.

Code of Federal Regulations, 2011 CFR

2011-04-01

... tube is a device consisting of a hollow copper tube intended to take an impression of a single tooth. The hollow tube is filled with impression material. One end of the tube is sealed with a softened...

Redesign of a fixture mount to be used as an impression coping and a provisional abutment as well

PubMed Central

Chang, Glenn Hsuan-Chen; Tian, Chen; Hung, Yuen-Siang

2011-01-01

Purpose: An integrated fixture mount/impression coping/ temporary abutment can provide many advantages for immediate loading of dental implants, such as simpler procedure, less chair time, cost reduction, and comfort for the patients. Materials and Methods: A newly designed dental implant fixture mount (DIFMA) can be used as an impression coping for taking an immediate impression. An immediate load provisional prosthesis can then be fabricated shortly after implant placement to immediately load the implants. This fixture mount can also serve as a temporary abutment for immediate chair-side fabrication of provisional prosthesis. Two clinical cases are presented. Results: A clinical case utilizing the fixture mount abutment (DIFMA)/implant assembly is presented. The precision of fitting between the impression copings and implants is secured with this system. The chair time for taking an immediate impression is greatly reduced. Less cost for the restoration is provided and patient comfort is delivered. Conclusions: More patient satisfaction can be conferred by employing the fixture mount in the process of immediate impression taking and as an immediate provisional abutment. PMID:22090763

Single Stage Silicone Border Molded Closed Mouth Impression Technique-Part II.

PubMed

Solomon, E G R

2011-09-01

Functioning of a complete denture depends to a great extent on the impression technique. Several impression techniques have been described in the literature since the turn of this century when Greene [Clinical courses in dental prothesis, 1916] brothers introduced the first scientific system of recording dental impression. Advocates of each technique have their own claim of superiority over the other. The introduction of elastomeric impression materials [Skinner and Cooper, J Am Dent Assoc 51:523-536, 1955] has made possible new techniques of recording impression for complete denture construction. These rubber like materials are of two types; one has a polysulfide base and is popularily known as polysulfide rubber (Thiokol and Mercaptan). The other variety has a silicone base known as silicone rubber or silicone elastomer. Silicone elastomers are available in four different consistencies; a thin easy flowing light bodied material,a creamy medium bodied material, a highly viscous heavy bodied material and a kneadable putty material. This paper describes an active closed mouth impression technique with one stage border molding using putty silicone material as a substitute for low fusing compound.

Intuitive visual impressions (cogs) for identifying clusters of diversity within potato species

USDA-ARS?s Scientific Manuscript database

One of the basic research activities of genebanks is to partition stocks into groups that facilitate the efficient preservation and evaluation of the full range of useful phenotype diversity. We sought to test the usefulness of making of infra-specific groups by replicated rapid visual intuitive imp...

Taking on Multitasking

ERIC Educational Resources Information Center

Rekart, Jerome L.

2011-01-01

Multitasking impedes learning and performance in the short-term and may affect long-term memory and retention. The implications of these findings make it critical that educators and parents impress upon students the need to focus and reduce extraneous stimuli while studying or reading. Course-based quizzes and tests can be used for more than…

A Psychometric Framework for the Evaluation of Instructional Sensitivity

ERIC Educational Resources Information Center

Naumann, Alexander; Hochweber, Jan; Klieme, Eckhard

2016-01-01

Although there is a common understanding of instructional sensitivity, it lacks a common operationalization. Various approaches have been proposed, some focusing on item responses, others on test scores. As approaches often do not produce consistent results, previous research has created the impression that approaches to instructional sensitivity…

The Development of Face Perception in Infancy: Intersensory Interference and Unimodal Visual Facilitation

ERIC Educational Resources Information Center

Bahrick, Lorraine E.; Lickliter, Robert; Castellanos, Irina

2013-01-01

Although research has demonstrated impressive face perception skills of young infants, little attention has focused on conditions that enhance versus impair infant face perception. The present studies tested the prediction, generated from the intersensory redundancy hypothesis (IRH), that face discrimination, which relies on detection of visual…

CAD/CAM, Creativity, and Discipline Lead to Turnaround School Success

ERIC Educational Resources Information Center

Gorman, Lynn

2012-01-01

Miami Central High School technology teacher Frank Houghtaling thinks the connection between theory and application is one reason his students perform better on the Florida Comprehensive Assessment Test (FCAT). The impressive turnaround school drew local and national attention last spring when one of Houghtaling's students, Dagoberto Cruz, won…

Effects of Impression Management Efforts on FIROB Profiles

ERIC Educational Resources Information Center

Hinrichsen, James J.; And Others

1975-01-01

Thirty male and 30 female undergraduates were tested in six groups of 10. Each subject completed the FIRO-B under three different instructional sets. The instructional sets were (a) "normal condition", (b) "fake good", and (c) "fake bad". The study revealed that the FIRO-B is susceptible to undetected faking. (Author)

A multicenter randomized, controlled clinical trial comparing the use of displacement cords, an aluminum chloride paste, and a combination of paste and cords for tissue displacement.

PubMed

Einarsdottir, Erna R; Lang, Niklaus P; Aspelund, Thor; Pjetursson, Bjarni E

2018-01-01

Gingival recession after soft tissue displacement for impression making in fixed prosthodontics may pose a problem for treatment success in the esthetic areas of the mouth. Knowledge about the soft tissue reaction of common gingival displacement methods is limited. The purpose of this clinical randomized controlled trial (RCT) was to evaluate changes in the marginal soft tissue height with 3 different gingival tissue displacement techniques for definitive impression making of natural teeth. A total of 67 individuals were randomized to 3 groups. In test group 1 (P; n=22), only aluminum chloride paste was used to displace the gingiva. In test group 2 (CP; n=23), a cord was inserted, and aluminum chloride paste was also used. In the control group (C; n=22), 2 cords were used to displace the gingiva (double-cord technique). Clinical measurements of the gingival position were made before treatment began and at 30 ±10 days after prosthesis delivery. Study casts were fabricated at different stages of the treatment, standardized photographs were made, and changes in the buccal gingival position were measured using graphics editing software. In addition, the participants' perception of the clinical procedure and the technicians' evaluation of the die preparation were recorded. One-way ANOVA models were applied to compare the response variables among the groups: (a) the position of the gingival margin (millimeters), (b) mean probing pocket depth (millimeters), (c) gingival thickness (millimeters), (d) amount of keratinized tissue (millimeters), and (e) mean changes in gingival margin height (millimeters). Unpaired t tests were also used to compare the mean values between groups. For comparisons between different categories, chi-square tests were performed (α=.05 for all tests). In the period between impression and delivery, a minor gain in gingival height of 0.058 mm (±0.13 SD) for P and 0.013 mm (±1.19 SD) for CP. However, a minor gingival recession of 0.049 mm (±0.13 SD) was reported for group C. The results for all groups showed that 21% of abutment teeth gained >0.1 mm in gingival height, 58% had stable gingival height (0 ±0.10 mm), 21% showed minor gingival recession (0.1 to 0.5 mm), and no abutment teeth showed moderate or severe gingival recession (>0.5 mm). The incidence of minor gingival recession was 8% in group P, 23% in group CP, and 32% in group C (P=.015). Fifteen participants (24%) experienced some discomfort after the procedure. The differences between the groups were not significant (P>.05). The laboratory technicians found the definitive die preparation significantly more challenging for group P (visual analog scale [VAS], 79) and CP (VAS, 82) than group C (mean VAS, 93; P=.003). Minor or moderate gingival recession (<1 mm) is more likely to occur when conventional cords are used during impression making. However, the laboratory technicians found the die preparation significantly less challenging when the double-cord technique was used than when impressions were made using the paste displacement technique. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Pigeons (Columba livia) know when they will need hints: prospective metacognition for reference memory?

PubMed

Iwasaki, Sumie; Watanabe, Sota; Fujita, Kazuo

2018-03-01

Despite their impressive cognitive abilities, avian species have shown less evidence for metacognition than mammals. We suspect that commonly used tasks such as matching to sample might be too demanding to allow metacognitive processing within birds' working memory. Here, we examined whether pigeons could control their behavior as a function of knowledge levels on a three-item sequence learning task, a reference memory task supposedly requiring fewer working memory resources. The experiment used two types of lists differing in familiarity. One was familiar to the pigeons through repeated exposure, whereas the other was novel in every new session. In test sessions, pigeons could choose between a trial with a hint specifying the next item to peck and one with no hint. However, successful responses in trials with a hint resulted in lowered rates of primary reinforcement: .60 in the first test and .75 in the second. Results showed that two of four pigeons chose the trial with a hint significantly more often before receiving a novel list than the familiar list in the four sessions of the first test, and three did so in the second test. Impressively, one bird showed robust evidence in the very first sessions in both tests. These results suggest that pigeons may monitor their long-term knowledge states and thereby control their environment before starting to solve a task.

Clinic-cytologic study of conjunctivochalasis and its relation to thyroid autoimmune diseases: prospective cohort study.

PubMed

de Almeida, Sandra Flavia Fiorentini; de Sousa, Luciene B; Vieira, Luis A; Chiamollera, Maria I; Barros, Jeison de N

2006-08-01

To determine the prevalence of conjunctivochalasis in patients with immune thyroid diseases, to determine whether there is any association between the 2 diseases, and to determine cytologic study of conjunctivochalasis through the cytology impression test. A clinical prospective cohort study carried out by the External Diseases Department in the Ophthalmology Sector and the Thyroid Department in the Endocrinology Sector at Federal University of Sao Paulo (UNIFESP). The patients included were divided into 2 groups following these inclusion criteria: a control group of 25 patients without thyroid diseases, confirmed after clinical and laboratory examinations (thyroid hormones), or any other ocular diseases. The study group consisted of 31 patients with thyroid diseases, the diagnosis of which was confirmed by the Endocrinology Sector. The thyroidopathies included were autoimmune diseases but excluded nonautoimmune diseases. A protocol endorsed by the UNIFESP was followed, using clinical and ophthalmological history, biomicroscopy, and impression cytology. Fifty-two percent of patients without thyroid diseases and 88% of patients with thyroid diseases presented with conjunctivochalasis. The risk ratio was 1.705 (Pr > chi(2) = 0.0038), indicating that there is an association between them. For the impression cytology in inferior bulbar conjunctiva, there was an association between the result of the impression cytology and conjunctivochalasis (Pearson chi(2) = 10.1190 Pr = 0.006). The prevalence of conjunctivochalasis in patients with autoimmune thyroid diseases was 88%. Patients with autoimmune thyroidopathy presented higher percentages of conjunctivochalasis than the control group, confirming the association between them. The cytologic study showed the highest prevalence of abnormal surface features in eyes with conjunctivochalasis.

Effect of camera angulation on adaptation of CAD/CAM restorations.

PubMed

Parsell, D E; Anderson, B C; Livingston, H M; Rudd, J I; Tankersley, J D

2000-01-01

A significant concern with computer-assisted design/computer-assisted manufacturing (CAD/CAM)-produced prostheses is the accuracy of adaptation of the restoration to the preparation. The objective of this study is to determine the effect of operator-controlled camera misalignment on restoration adaptation. A CEREC 2 CAD/CAM unit (Sirona Dental Systems, Bensheim, Germany) was used to capture the optical impressions and machine the restorations. A Class I preparation was used as the standard preparation for optical impressions. Camera angles along the mesio-distal and buccolingual alignment were varied from the ideal orientation. Occlusal marginal gaps and sample height, width, and length were measured and compared to preparation dimensions. For clinical correlation, clinicians were asked to take optical impressions of mesio-occlusal preparations (Class II) on all four second molar sites, using a patient simulator. On the adjacent first molar occlusal surfaces, a preparation was machined such that camera angulation could be calculated from information taken from the optical impression. Degree of tilt and plane of tilt were compared to the optimum camera positions for those preparations. One-way analysis of variance and Dunnett C post hoc testing (alpha = 0.01) revealed little significant degradation in fit with camera angulation. Only the apical length fit was significantly degraded by excessive angulation. The CEREC 2 CAD/CAM system was found to be relatively insensitive to operator-induced errors attributable to camera misalignments of less than 5 degrees in either the buccolingual or the mesiodistal plane. The average camera tilt error generated by clinicians for all sites was 1.98 +/- 1.17 degrees.

Sweat testing to evaluate autonomic function

PubMed Central

Illigens, Ben M.W.; Gibbons, Christopher H.

2011-01-01

Sudomotor dysfunction is one of the earliest detectable neurophysiologic abnormalities in distal small fiber neuropathy. Traditional neurophysiologic measurements of sudomotor function include thermoregulatory sweat testing (TST), quantitative sudomotor axon reflex testing (QSART), silicone impressions, the sympathetic skin response (SSR), and the recent addition of quantitative direct and indirect axon reflex testing (QDIRT). These testing techniques, when used in combination, can detect and localized pre- and postganglionic lesions, can provide early diagnosis of sudomotor dysfunction and can monitor disease progression or disease recovery. In this article, we review the common tests available for assessment of sudomotor function, detail the testing methodology, review the limitations and provide examples of test results. PMID:18989618

Fabrication of customized sectional impression trays in management of patients with limited mouth opening: a simple and unique approach.

PubMed

Krishna Ch, Vamsi; Mahendranadh Reddy, K; Gupta, Nidhi; Mahadev Shastry, Y; Chandra Sekhar, N; Aditya, Venkat; Reddy, G V K Mohan

2013-01-01

Impression making is not only important but is also the most significant step in the fabrication of any fixed or removable prosthesis. Proper impression making may be hindered by certain pathologic conditions. Reduced mouth opening is one of the common mechanical obstructions for proper orientation of the impression tray in the patient's mouth. In patients with trismus induced by submucous fibrosis, the procedure may be even more difficult to carry out because of reduced tissue resiliency and obliteration of vestibular spaces. Use of sectional trays offers one of the alternatives to overcome the problem of restricted mouth opening. Fabrication of customized impression trays according to the patient dentition improves the accuracy of impression making. The present case reports describe the fabrication of sectional custom trays designed for dentulous patients with chronic tobacco-induced submucous fibrosis.

The neural dynamics of updating person impressions

PubMed Central

Cai, Yang; Todorov, Alexander

2013-01-01

Person perception is a dynamic, evolving process. Because other people are an endless source of social information, people need to update their impressions of others based upon new information. We devised an fMRI study to identify brain regions involved in updating impressions. Participants saw faces paired with valenced behavioral information and were asked to form impressions of these individuals. Each face was seen five times in a row, each time with a different behavioral description. Critically, for half of the faces the behaviors were evaluatively consistent, while for the other half they were inconsistent. In line with prior work, dorsomedial prefrontal cortex (dmPFC) was associated with forming impressions of individuals based on behavioral information. More importantly, a whole-brain analysis revealed a network of other regions associated with updating impressions of individuals who exhibited evaluatively inconsistent behaviors, including rostrolateral PFC, superior temporal sulcus, right inferior parietal lobule and posterior cingulate cortex. PMID:22490923

Very first impressions.

PubMed

Bar, Moshe; Neta, Maital; Linz, Heather

2006-05-01

First impressions of people's personalities are often formed by using the visual appearance of their faces. Defining how quickly these impressions can be formed has critical implications for understanding social interactions and for determining the visual properties used to shape them. To study impression formation independent of emotional cues, threat judgments were made on faces with a neutral expression. Consequently, participants' judgments pertained to the personality rather than to a certain temporary emotional state (e.g., anger). The results demonstrate that consistent first impressions can be formed very quickly, based on whatever information is available within the first 39 ms. First impressions were less consistent under these conditions when the judgments were about intelligence, suggesting that survival-related traits are judged more quickly. The authors propose that low spatial frequencies mediate this swift formation of threat judgments and provide evidence that supports this hypothesis. 2006 APA, all rights reserved

Motivation alters impression formation and related neural systems

PubMed Central

Zaki, Jamil; Ambady, Nalini

2017-01-01

Abstract Observers frequently form impressions of other people based on complex or conflicting information. Rather than being objective, these impressions are often biased by observers’ motives. For instance, observers often downplay negative information they learn about ingroup members. Here, we characterize the neural systems associated with biased impression formation. Participants learned positive and negative information about ingroup and outgroup social targets. Following this information, participants worsened their impressions of outgroup, but not ingroup, targets. This tendency was associated with a failure to engage neural structures including lateral prefrontal cortex, dorsal anterior cingulate cortex, temporoparietal junction, Insula and Precuneus when processing negative information about ingroup (but not outgroup) targets. To the extent that participants engaged these regions while learning negative information about ingroup members, they exhibited less ingroup bias in their impressions. These data are consistent with a model of ‘effortless bias’, under which perceivers fail to process goal-inconsistent information in order to maintain desired conclusions. PMID:27798250

ETI: Our first impressions

NASA Astrophysics Data System (ADS)

Harrison, Albert A.; Johnson, Joel T.

2000-06-01

Despite scant or ambiguous information, people are capable of developing comprehensive and detailed impressions. Consequently, if the detection of an electromagnetically-active civilization is announced, many people will rapidly form impressions of what the extraterrestrials and their civilization are "like". First impressions are crucial, not only because of their immediate psychological, social, and political consequences on Earth, but because they can influence the future of interstellar communication. Initial impressions will rest less on hard data than on the nature and tone of the "evidence" that is gleaned from the transmission; the interpretation and dissemination of this evidence; and the hard wiring, psychological programming, cultural conditioning, and social influence processes that shape human perception. We consider how dispositional inferences, implicit theories of personality, negatively toned or adverse information, physical appearance, prior expectations, the confirmation bias, and thinking and unthinking approaches to attitude formation are likely to affect human impressions of ETI.