The purpose of this meta-analysis is to examine overall effect as well as the impact of selected instructional design principles in the context of virtual reality technology-based instruction (i.e. games, simulation, virtual worlds) in K-12 or higher education settings. A total of 13 studies (N?=?3081) in the category of games, 29 studies (N?=?2553) in the category of games, and 27 studies (N?=?2798) in the category of virtual worlds were meta-analyzed. The key inclusion criteria were that the study came from K-12 or higher education settings, used experimental or quasi-experimental research designs, and used a learning outcome measure to evaluate the effects of the virtual reality-based instruction.Results suggest games (FEM?=?0.77; REM?=?0.51), simulations (FEM?=?0.38; REM?=?0.41), and virtual worlds (FEM?=?0.36; REM?=?0.41) were effective in improving learning outcome gains. The homogeneity analysis of the effect sizes was statistically significant, indicating that the studies were different from each other. Therefore, we conducted moderator analysis using 13 variables used to code the studies. Key findings included that: games show higher learning gains than simulations and virtual worlds. For simulation studies, elaborate explanation type feedback is more suitable for declarative tasks whereas knowledge of correct response is more appropriate for procedural tasks. Students performance is enhanced when they conduct the game play individually than in a group. In addition, we found an inverse relationship between number of treatment sessions learning gains for games.With regards to the virtual world, we found that if students were repeatedly measured it deteriorates their learning outcome gains. We discuss results to highlight the importance of considering instructional design principles when designing virtual reality-based instruction. A comprehensive review of virtual reality-based instruction research.Analysis of the moderation effects of design features in a virtual environment.Using an advance statistical technique of meta-analysis to study the effects.Virtual reality environment is effective for teaching in K-12 and higher education.Results can be used by instructional designers to design the virtual environments.

Effectiveness of virtual reality-based instruction on students' learning outcomes in K-12 and higher education

https://www.dentalxp.com/content/1863/8c629565-70a7-4c79-97a3-86b5e7206825.pdf

Dental color matching instruments and systems. Review of clinical and research aspects

Purpose: This review integrated the current literature on diffusion of whitening agents, their interactions with stain molecules, and changes to the surface, with the aim of establishing a better understanding of the mechanism underlying tooth whitening. Materials and Methods: An electronic PubMed database search, with combinations of the following terms was performed:Tooth Bleaching,Tooth Bleaching Agent, Hydrogen Peroxide, Pharmacokinetics,Tooth Permeability, Oxidation-Reduction,Tooth Demineralization, and Color. Results: Tooth whitening is a dynamic process that involves diffusion of the whitening material to interact with stain molecules and also involves micromorphologic alterations on the surface and changes within the tooth that affect its optical properties.The interaction seems not to be limited to stain molecules, but rather an affinity-based interaction process that also accompanies effects on sound enamel and dentin structures. Conclusions: This review underlines that supervision by dental health professionals as recommended by the American Dental Association (ADA) Council on Scientific Affairs is critical to achieving a successful and safe whitening outcome. CLINICAL SIGNIFICANCE The mechanism that underlies tooth whitening with the use of peroxide-based materials is a complex phenomenon encompassing diffusion, interaction, and surfaces changes within the tooth.Therefore, supervision by dental health professionals as recommended by the ADA Council on Scientific Affairs is imperative to achieve a successful and safe whitening outcome. (J Esthet Restor Dent ••:••-••, 2015)

Review of the Mechanism of Tooth Whitening

Color related to ceramic and zirconia restorations: A review

Tooth whitening: what we now know.

Erosion and abrasion of tooth-colored restorative materials and human enamel

Spectrophotometric evaluation of the optical influence of core build-up composites on all-ceramic materials.

Colour and surface analysis of carbamide peroxide bleaching effects on the dental restorative materials in situ.

Effects of bleaching gels on the surface microhardness of tooth-colored restorative materials in situ.

The purpose of this study was to evaluate the colour errors of visual shade selection by five different shade guides. The maxillary left central incisors of sixty participants were visually evaluated by two groups of prosthodontists, with different clinical experience. The shade selection results were recorded and the most selected tab was determined as the resultant shade for each tooth. If totally different opinions were obtained, consensus was needed to determine the resultant shade among the observers. The colour distributions (L*, a* and b*) of each tooth and shade tab were measured using a spectroradiometer. The coverage errors (CEs) of each shade guide and colour differences (DeltaE values) between a tooth and the selected shade tabs were calculated. Two-way anova and Tukey's post hoc analysis were used to evaluate the differences of CE and DeltaE values among shade guides and clinical experience (alpha = 0.05). Coverage errors and DeltaE values in all of the five shade guide systems were all beyond the clinical threshold of 3.3 units. The consensus led to a better colour matching than that of the single decision group in Vitapan 3D-Master and Shofu NCC shade guides. A significant difference (P < 0.001) was found among DeltaE values of the shade guide system and clinical experience. In conclusion, all five of the shade guide systems used did not achieve clinically compatible shade matching. However, the Vitapan 3D Master shade guide system resulted in the lowest CEs and DeltaE values. Consensus could be helpful in enhancing the aesthetic results using Vitapan 3D Master and Shofu NCC shade guides.

Hao Yu

Papers

Erosion and abrasion of tooth-colored restorative materials and human enamel

Spectrophotometric evaluation of the optical influence of core build-up composites on all-ceramic materials.

Colour and surface analysis of carbamide peroxide bleaching effects on the dental restorative materials in situ.

Effects of bleaching gels on the surface microhardness of tooth-colored restorative materials in situ.

In vivo spectroradiometric evaluation of colour matching errors among five shade guides.