Effects of Different Concentrations of Carbamide Peroxide on Color, Surface Roughness, and Hardness of CAD/CAM Dental Ceramics.

OBJECTIVES: This study assessed the effects of 15% and 20% carbamide peroxide (CP) on color, surface roughness, and hardness of computer-aided design/computer-aided manufacturing (CAD/CAM) dental ceramics. MATERIALS AND METHODS: This in vitro study was conducted on 120 Vita Mark II, Celtra Duo, and Suprinity CAD/CAM ceramic specimens. The ceramic specimens in each group (n = 40) were randomly assigned to two subgroups (n = 20) for polishing and glazing, and their baseline color, surface roughness (Ra), and hardness were assessed. In each subgroup, half of the specimens were exposed to 15% CP, while the other half were exposed to 20% CP. Their color change (ΔE), surface roughness, and hardness were then measured again. Surface roughness, hardness, and color were analyzed sequentially by profilometer, Vickers hardness tester, and spectrophotometer, respectively. Data were analyzed by repeated measures ANOVA, one-way ANOVA, and post hoc Bonferroni test (α = 0.05). RESULTS: The surface roughness of all groups significantly increased after bleaching treatment (p < 0.05). Surface hardness of all groups decreased after bleaching treatment, but this reduction was only significant in Vita Mark II subgroups (glazed, polished, 15%, and 20% CP). The ΔE was not clinically and visually perceivable in any group. CONCLUSION: The present results revealed that concentration of CP and type of surface treatment affected the surface properties of CAD/CAM ceramics. Type of surface treatment only affected the surface hardness of Vita Mark II ceramics (p < 0.05). Concentration of CP had a significant effect only on polished Vita Mark II.

Adapting to Change: A Systematic Literature Review of Environmental Flexibility in Emergency Departments.

PURPOSE: This study aimed to offer a comprehensive analysis of distinct design strategies identified, evaluated, or discussed in the existing literature that promote environmental flexibility in the context of emergency departments (EDs). BACKGROUND: EDs are subject to constant changes caused by several factors, including seasonal disease trends, the emergence of new technologies, and surges resulting from local or global disasters, such as mass casualty incidents or pandemics. Thus, integrating flexibility into ED design becomes crucial to effectively addressing these evolving needs. METHODS: A systematic search was conducted in four databases: CINAHL, MEDLINE, PubMed, and ScienceDirect, in addition to a hand search. A two-stage review process was employed to determine the final list of included articles based on the inclusion criteria. Included studies were evaluated for quality, and findings were categorized using a hybrid deductive and inductive coding approach. RESULTS: From the initial yield of 900 records, 22 studies met the inclusion criteria and were included in the final full-text review. The identified design strategies were organized into five categories: modifiability (n = 13 articles), versatility (n = 8 articles), tolerance (n = 6 articles), convertibility (n = 4 articles), and scalability (n = 7 articles). Specific design strategies under each category are reported in detail. CONCLUSIONS: Our findings suggest that most flexibility design solutions are based on anecdotal evidence or descriptive studies, which carry less weight in terms of reliable support for conclusions. Therefore, more studies employing quantitative, relational, or causal designs are recommended.

Hierarchy of Evidence: An Appraisal Tool for Weighting the Evidence in Healthcare Design Research Based on Internal Validity.

PURPOSE: This inquiry aims to develop an appraisal tool to offer greater granularity in weighing evidence in the field of healthcare design research. BACKGROUND: In evidence-based design (EBD), the goal is to implement interventions that result in a meaningful and optimal effect based on current best evidence. Although multiple appraisal tools (many adopted from medical disciplines) have been instrumental in evaluating studies in the field of healthcare design research to identify the best evidence, they do not necessarily consider the unique contexts of healthcare design research, and methodologies appropriate to the field. METHODS: Five basic types of studies are ranked based on the level of confidence that they offer regarding the estimate of an effect: (1) meta-analysis studies, (2) causal studies, (3) correlational studies, (4) descriptive studies, and (5) anecdotal evidence. Causal studies are further divided into four levels based on the interaction of two factors: (1) type of intervention and (2) groups' equivalency and extraneous variable control. RESULTS: An eight-level hierarchy of evidence for healthcare design research is proposed that is expected to improve upon previous hierarchies in three major ways: (a) including research methods that are more relevant to healthcare design research, (b) enhancing evaluation accuracy and reliability by providing a clearer definition of studies based on their key components rather than using study labels alone, and (c) distinguishing different levels of evidence, particularly in causal studies. CONCLUSIONS: The proposed appraisal tool is developed specifically for EBD by reflecting on the unique context of healthcare design research and practice.

A Narrative Review of Theories of Wayfinding Within the Interior Environment.

PURPOSE: The aim of this article is to provide a narrative overview of theories that are available in the published literature on wayfinding in interior environments. BACKGROUND: Wayfinding is an issue in healthcare facilities, and it has been documented that wayfinding problems have negative impacts on patients, visitors, caregivers' time, and the organization's bottom line. This issue can be more challenging for people with illness, low vision, cognitive disorders, and limited physical mobility. Wayfinding is a complex phenomenon depending on a variety of cognitive processes and behaviors. METHODS: This article is a part of a broader literature review that searched for empirical studies on interior wayfinding. Four databases were systematically searched-PsychINFO, JSTOR, ProQuest, and EBSCO. A total of 81 articles satisfied all inclusion criteria for the broader study. Each article included in the broader study was reviewed to identify theory or theories, if any, that a study was founded on. RESULTS: After an in-depth review of the theories, the authors proposed four categories of theories relating to human wayfinding. The four classes and the specific theories in those are articulated in this article, including major changes during their evolution. The four classes of theories explain four facets of wayfinding: (1) theories of perception, (2) theories of spatial knowledge development, (3) theories of mental representation of spatial knowledge, and (4) theories of spatial cognition. CONCLUSION: Since wayfinding is essentially a cognitive/problem-solving phenomenon, understanding the theoretical underpinnings of wayfinding may result in more meaningful and impactful design decisions.

The Impact of the Built Environment on Patient Falls in Hospital Rooms: An Integrative Review.

OBJECTIVES: The aims of this study were to identify and evaluate scientific evidence examining the impact of the built environment on patient falls in hospital rooms. METHODS: An integrative review (IR) with a systematic literature search was performed using the patient, intervention, comparison, outcome framework. We searched CINAHL, PsychINFO, PubMED, and Web of Science databases. The search included peer-reviewed studies from 1990 to 2017 written in English. An additional hand search was also conducted. Selected articles were reviewed and rated based on a hierarchical categorization, comprising six evidence levels, developed by the American Association of Critical-Care Nurses and adapted for evidence-based design systematic literature reviews. RESULTS: After a multitiered process, 30 articles met the selection criteria. Thematic areas were created based on the examined elements of the physical environment including patient room configuration and available space, bathroom configuration, bathtub and shower, door, bed height and bed rail, flooring, floor mats, patient chair, lighting, toilet, handrail, grab bars, intravenous pole, sink, ceiling lift, and wheelchair and walking aids. Findings of studies on each element are discussed in detail. CONCLUSIONS: Some environmental elements have not been examined in past relational or causal studies, and the level of evidence for the examined attributes is not high enough to gain robust confidence in healthcare design decision-making. Because of the low level of evidence for several environmental elements, conclusions must be taken with caution. More studies using quantitative, relational, or causal designs are recommended to develop actionable interventions on patient falls in hospital rooms.

Wayfinding in Interior Environments: An Integrative Review.

Wayfinding is an issue in complex facilities-including hospitals, airports, and office buildings-and wayfinding difficulties are associated with negative psychological and physiological consequences. In addition, since finding one's way in a building is a prerequisite for successfully using that building, wayfinding has attracted the attention of scholars and decision makers. The goal of this article is to review and synthesize the published literature on wayfinding in interior environments. A systematic search was conducted of four databases: PsychINFO, JSTOR, ProQuest, and EBSCO. A hand search was also conducted. From the initial harvest of 804 records, a total of 84 records met the inclusion criteria for full review. After several rounds of review, four broad domains were identified: (1) wayfinding cognition, (2) wayfinding behavior, (3) individual and group differences, and (4) environmental factors. These domains are used as a framework to organize the findings, and the review shows that the sub-domains most thoroughly addressed in the literature are spatial memories, floor plan configuration, landmarks, signs, and maps. This review can deepen the field's understanding of factors that contribute to interior wayfinding and can serve as a resource for decision makers and designers.

Evaluation of scalp hair nickel and chromium level changes in patients with fixed orthodontic appliance: a one-year follow-up study.

BACKGROUND AND OBJECTIVES: The release of metal ions from orthodontic appliances is part of the dissolution and biomechanical processes of alloys. Nickel (Ni) and chromium (Cr) are the elements commonly used in the manufacture of various components of fixed orthodontic appliances, including bands, brackets and wires. This study was aimed to measure the Ni and Cr ions levels in the scalp hair of patients treated with fixed orthodontic appliances in comparison of the control group. MATERIALS AND METHODS: The patient group consisted of 24 patients treated with fixed orthodontic appliances for one year, while the control group included 28 healthy individuals without orthodontic appliances. Analysis of the Cr and Ni was performed using atomic absorption spectrophotometer by graphite furnace method. The data were analyzed via student and paired samples t-test and ANOVA repeated measurement test. RESULTS: After one year, the levels of Ni and Cr in two groups showed significant differences (0.086 ± 0.007 and 0.258 ± 0.009 µg/g for control group and 0.149 ± 0.010 and 0.339 ± 0.013 µg/g for patient group, respectively for Ni and Cr, p < .001). ANCOVA test by removing the effects of age, gender and the baseline levels of Ni and Cr showed that changes in these ions in the scalp hair of both groups after one year were statistically significant. CONCLUSION: Due to the slightly elevated levels of Ni and Cr ions in the scalp hair of patients treated with fixed orthodontic appliances and considering the cytotoxic and allergic effects of these ions, changing the ingredients in fixed orthodontic appliances is suggested for the future.