Authors: Xiaoyi Zhao, Jie Pan, Hans Malmstrom...

: Tooth whitening is a relatively conservative and effective option to treat discolored teeth. However, questions remain whether in-office or at-home tooth whitening products with short treatment durations are as effective and stable as products with longer treatment durations. : Forty human third molars with intact enamel surfaces were divided into four groups of ten each, subjected to discoloration challenges with coffee for 60 h, and they were treated with four professional tooth whitening systems: two for take-home use-6% hydrogen peroxide for 30 min/d for a total of 7 h in 14 days (HP6), 10% carbamide peroxide for 10 h/d for 140 h in 14 days (CP10), as well as two for in-office use-35% HP for 10 min × 3 (HP35) for a total of 30 min and 40% HP for 20 min × 3 (HP40) for a total of 60 min. Teeth colors were assessed in the CIE L*a*b* color space with a spectrophotometer immediately and six months after whitening treatments. Surface roughness (Sa) for the treated and untreated enamel surfaces of the teeth in all groups were evaluated with a three-dimensional laser scanning microscope after six months. : No significant differences were found between HP6 and CP10 groups immediately after whitening (∆ 10.6 ± 1.6 vs. 11.4 ± 1.7, > 0.05) and at six months after treatments (∆ 9.0 ± 1.9 vs. 9.2 ± 2.5, > 0.05), or between HP35 and HP40 groups immediately after whitening (∆ 5.9 ± 1.2 vs. 5.3 ± 1.7, > 0.05) and at six months after treatments (∆ 7.2 ± 1.6 vs. 7.7 ± 1.3, > 0.05). The two at-home whitening systems achieved significantly better whitening outcomes than the two in-office products immediately after whitening ( < 0.05). However, at six months after treatments, the differences between at-home and in-office treatments had narrowed significantly ( > 0.05). There were no statistically significant differences with respect to the Sa values between the treated and untreated surfaces ( > 0.05). : Tooth whitening products in the same product category have similar whitening efficacies, despite significant differences in treatment durations (7 vs. 140 h, and 30 min vs. 60 min, respectively). Take-home products achieved better whitening outcomes than in-office products, but they needed 14 to 280 times longer treatment durations.

Topics: Humans; Tooth Bleaching; Duration of Therapy; Urea; Color; Hydrogen Peroxide

PubMed: 37374334
DOI: 10.3390/medicina59061130

Authors: S Ugur, B Gunal

BACKGROUND AND AIMS

Evaluation of the optical properties of restorative materials is an important parameter for identifying clinical success. The aim of this study was to compare the translucency of contemporary resin-matrix ceramics (RMCs) and to evaluate the effect of cement shade on the final color of RMCs indicated for laminate veneers and full crowns.

MATERIALS AND METHODS

A hundred A2 shade RMC specimens were fabricated by using Mazic Duro (MD), CAMouflage NOW (CN), KZR-CAD HR2 (KZR), Grandio Block (GB), and Brilliant Crios (BC) at 0.7-mm and 1.5-mm thicknesses (n = 10). A2 shade composite resin was used for the foundation structure. Twenty resin-cement specimens were prepared from A2 and translucent shades at 0.1-mm thickness. Interchangeably, the foundation-cement-resin matrix ceramic assemblies were created with optical gel. The color coordinates were recorded using a spectrophotometer. After calculating translucency parameter (TP) and color difference (ΔE) values, data were analyzed statistically (P = 0.05).

RESULTS

TP values were influenced by RMC type and thickness. TP values of RMCs can be listed in descending order as MD>GB = CN>BC=KZR. ΔE values were significantly influenced by all parameters and their interactions. MD exhibited higher ΔE values among tested RMCs. The effect of A2 cement was not perceived visually while TR cement demonstrated visually perceptible but clinically acceptable values for both laminate veneers and full crowns. As the material thickness decreased, the TP and ΔE values increased in all RMCs.

CONCLUSIONS

Clinicians should carefully prefer cement shade and RMC material by contemplating their impact on the optical properties particularly when the restoration is thin.

Topics: Ceramics; Color; Glass Ionomer Cements; Humans; Materials Testing; Prosthesis Coloring; Resin Cements; Surface Properties

PubMed: 35975382
DOI: 10.4103/njcp.njcp_172_22

Authors: R Draghici, C T Preoteasa, Amc Ţâncu...

UNLABELLED

To verify the impact of taking the Toothguide Training Box (TTB) exercise in improving the individual ability to correctly determine dental color. A prospective study was conducted on the 5th year dental students. The participants were required to carry out 3 distinct steps: visual color determination for sample tabs out of the 3DMaster shade guide, the TTB exercise and another color determination after training completion. The sample included 60 students (19M/ 41F) with a mean age of 24, which made 360 color determinations of 6 shade tabs before and after TTB exercise. 32,5% (n=117) of the color determinations were incorrect in both moments, and the value was incorrectly determined just in 11% of them. Students found 3L1.5 and 3M2 colors as the hardest to determine. The results suggested that a single TTB training exercise did not have a high positive influence on the individual capacity to correctly determine the color for tabs out of the shade guide. While there is no evidence of an immediate positive impact of the TTB exercise in evaluating and determining different color variations for sample key elements, through repeat exercises, the individual perception can be improved and thus the correct determination of dental color and its correct codification can be increased.

ABBREVIATIONS

TTB = Tooth Training Box, CIE = Commission internationale de l'éclairage, L = lightness, C = chroma, H = hue.

Topics: Adult; Color; Color Perception; Female; Humans; Male; Prospective Studies; Prosthesis Coloring

PubMed: 27974916
DOI: No ID Found

Authors: Manuela Maria Manziuc, Cristina Gasparik, Alexandru Victor Burde...

Purpose 1. to assess the ability of four brands of translucent monolithic zirconia with different thicknesses to mask discolored substrates; 2. to assess the influence of glazing upon their color coordinates and masking properties.Methods Sixty samples of shade A1 (0.8, 1.5, and 2.0 mm thickness) from: ZirCAD/MT, Katana/HT, Vita YZ/HT, Cercon/HT were fabricated and glazed using a standardized laboratory procedure. CIE L*a*b* parameters were recorded on composite substrates, (IPS Natural Die Material Kit) (ND1=reference; ND2, ND3, ND4, ND5=test backgrounds), before and after glazing. The color changes of zirconia samples induced by glazing were analyzed. Masking properties was calculated as the color difference between CIE L*a*b* parameters of the samples placed on reference and test substrates with CIEDE2000(1:1:1) formula. The effect of material, thickness, substrate, and glazing on the color of monolithic zirconia was analyzed with ANOVA test and the multiple comparisons were analyzed with Tukey HSD tests (α=0.05).Results After glazing, lightness L* significantly increased, while chromatic coordinates a* and b* decreased (p<0.05). Significant differences in the masking properties of the four materials (p<0.001) were found, with IPS e.max ZirCAD/MT having the lowest masking effect (p<0.001). Thickness, substrate and glazing had a significant effect on the color masking properties of monolithic zirconia (p<0.001).Conclusions Masking properties of translucent zirconia were significantly influenced by the materials, the thickness and the color of the substrate; moreover, glazing improved the masking ability for all zirconia samples.

Topics: Ceramics; Color; Dental Porcelain; Materials Testing; Surface Properties; Zirconium

PubMed: 33116028
DOI: 10.2186/jpr.JPR_D_20_00039

Authors: Eun-Sung Song, Won-Hyeon Kim, Beom-Hui Lee...

Nowadays, medical facilities are developing their treatment environment to provide better services to their patients. In particular, dental hospitals have been considered uncomfortable and uninviting spaces, which needs to change so that people can visit easily and feel more relaxed. However, only a few systematic studies have reported on the demand for building a comfortable space. This study aimed to investigate gaze characteristics based on a color preference survey of the dental unit chair, which has the most influence on spatial perception in the dental treatment environment, using an eye tracking technique for color. The results of this study showed that the color perception by eye tracking and the color preference by survey did not tend to match. The color most viewed by a majority of subjects was pink, which attracted a high level of attention, regardless of personal preference. In addition, for the psychological color images associated with color preference, the subjects tended to prefer images such as warmth, friendliness, and calmness. This appeared to reflect the psychology of the subjects who wished to replace their feelings of anxiety or fear when going to the dental hospital with comfort and tranquility. Therefore, colors that can provide comfort and tranquility to patients should be considered first as visual elements (e.g., brown) in creating a dental treatment environment.

Topics: Attention; Color; Color Perception; Dental Care; Eye-Tracking Technology; Humans; Space Perception

PubMed: 34360272
DOI: 10.3390/ijerph18157981

Authors: Cristina Espinar, Alvaro Della Bona, María M Pérez...

OBJECTIVE

Color and optical properties are particularly crucial to mimic natural tooth. This scoping review aimed to present an overview of the literature published on color and optical properties of 3D printing restorative polymer-based materials. The literature search was performed in MED-LINE/Pubmed, Scopus and Web of Science.

MATERIALS AND METHODS

The literature search was conducted in the three databases based on the question: "Are the optical properties and color adequately reported on polymer-based 3D printing dental restorative materials studies?" with no restriction on year of publication. Data were reported and synthesized following PRISMA-ScR statement.

RESULTS

Nine studies fit the inclusion criteria. Five studies focused on evaluating only color stability; three articles assessed the color stability along with mechanical and morphological properties and only one study compared color parameters of 3D printed to conventional polymers. Two studies evaluated translucency parameter and no study was found evaluating scattering, absorption, and transmittance.

CONCLUSIONS

Color and optical properties of 3D printed polymers that can be used in restorative dentistry are not adequately evaluated and characterized. Future studies on the influence of experimental printing conditions should include these physical properties to assist on improving esthetics.

CLINICAL SIGNIFICANCE

This review shows the scarce literature existing on color and optical properties of 3D printing restorative polymer-based materials. These properties and their study are of outmost importance to create materials that mimic natural tooth to allow clinicians to obtain esthetically pleasant restorations.

Topics: Color; Dentistry; Esthetics, Dental; Polymers; Printing, Three-Dimensional

PubMed: 35347852
DOI: 10.1111/jerd.12904

Authors: Anja Ratzmann, Alexander Welk, Stephanie Hoppe...

BACKGROUND

The aim of the study was to compare a 2D and 3D color system concerning a variety of statistical and graphical methods to assess validity and reliability of color measurements, and provide guidance on when to use which system and how to interpret color distance measures, including ΔE and d(0M1).

METHODS

The color of teeth 14 to 24 of 35 patients undergoing regular bleaching treatment was visually assessed and electronically measured with the spectrophotometer Shade Inspector™. Tooth color was recorded before bleaching treatment, after 14 days, and again after 6 months. VITAPAN® Classical (2D) and VITA-3D-Master® (3D) served as reference systems.

RESULTS

Concerning repeated measurements, the 2D system was superior to the 3D system, both visually and electronically in terms of ΔE and d(OM1), for statistics of agreement and reliability. All four methods showed strong patterns in Bland-Altman plots. In the 3D system, hue was less reliable than lightness and chroma, which was more pronounced visually than electronically. The smallest detectable color difference varied among the four methods used, and was most favorable in the electronic 2D system. Comparing the methods, the agreement between the 2D and 3D system in terms of ΔE was not good. The reliability of the visual and electronic method was essentially the same in the 2D and 3D systems; this comparability is fair to good.

CLINICAL RELEVANCE

The 3D system may confuse human raters and even electronic devices. The 2D system is the simple and best choice.

Topics: Color; Dental Prosthesis Design; Electronics; Humans; Reproducibility of Results; Spectrophotometry; Tooth

PubMed: 33323128
DOI: 10.1186/s13005-020-00248-w

Assessment of Color Stainability of Computer-Aided Design and Computer-Aided Manufacturing (CAD/CAM) Ceramic Materials After Hot and Cold Coffee Immersion at Different Time Intervals.

Authors: Hafiz A Adawi, Mohammed M Al Mialeem, Nasser M Al Ahmari...

BACKGROUND This spectrophotometric study assessed the color stability of CAD/CAM restorative materials with different exposed surfaces following staining by hot Arabic Qahwa and cold coffee. MATERIAL AND METHODS Ninety-six specimens were fabricated from 3 different CAD/CAM ceramic materials: Vita Suprinity (Vita-S), Vita Enamic (Vita-E), and Vitablocs Mark II (Vitablocs-MII). We divided 32 specimens for each group into glazed or polished surfaces, with 16 specimens in each group, then subdivided them according to staining materials: Arabic Qahwa and Frappuccino Cold Coffee. Color of specimens was measured during immersion in staining materials (BEFORE) as baseline with (Vita classic) and (L, a, b), for average color changes (ΔE₀₀), then remeasured after 2, 4, and 12 weeks, and described as 1st, 2nd, and 3rd measurements for VITAPAN Classic shade and T1, T2, and T3 for ΔE00 values using the CIE L*a*b* equation. We performed ANOVA and then post hoc testing. RESULTS We found significant differences in ΔE₀₀ values during immersing in hot Arabic Qahwa and cold coffee for tested materials in glazed or polished specimens. Polished specimens of Vita-S and Vita-E had the highest color changing and staining compared to glazed surfaces. Vitablocs-MII had the best color stability through immersion periods. Moreover, there were changes in relation to VITAPAN Classic shade guide for both Vita-S and Vita-E specimens during different immersion periods. CONCLUSIONS Coffee caused staining and contamination of ceramic material. Values of ΔE₀₀ for tested ceramic materials were significantly different but were within the clinically acceptable range. Polished specimens showed higher staining; therefore, we highly recommend re-glazing of ceramic restorations to maintain color stability.

Topics: Ceramics; Coffee; Color; Coloring Agents; Computer-Aided Design; In Vitro Techniques; Materials Testing; Spectrophotometry; Temperature; Time

PubMed: 34601487
DOI: 10.12659/MSM.932745

Authors: B Remonato Franco, T Shynkaruk, T Crowe...

Light is an important component in poultry production, and it may impact bird behavior, an important component of animal welfare. Light-emitting diode (LED) lamps are of interest for broiler production since they are inexpensive to run and provide monochromatic colors. This study aimed to understand the impact of three light colors (blue, green, or white), provided by LED lighting, on behavioral expression, stress and fear levels of broilers. A total of 14,256 male and female broilers of 2 genotypes (Ross EPMx708 and Ross YPMx708) were housed in 9 rooms in 2 blocked trials (3 room replicates per light per trial), with sexes and genotypes housed in 12 separate pens per room. Behavioral expression was recorded using an infrared camera and analyzed using a scan sampling technique. To assess fear, 3 tests were conducted: tonic immobility, novel object, and response to observer. Blood was collected to evaluate chronic stress using the heterophil:lymphocyte (H:L) ratio. Data were statistically analyzed using SAS (MIXED procedure) in a 3 × 2 × 2 factorial design, with lighting treatment nested within room. Fear tests indicated reduced fear levels in birds raised under blue light (lower latency to rise during the tonic immobility test and a lower percentage of birds moving due to the passage by of an observer). No differences were observed for the novel object test. Light color resulted in changes in stress levels, indicated by a lower H:L ratio for broilers raised under blue light compared to those raised under white light. Behavior was influenced by light color, especially at 33 to 34 d of age, where birds raised under white light were more active, and birds raised under blue light spent more time resting. Overall, results indicated that light color has minor influences on behavioral expression. Utilizing blue light during the brooding and rearing phase leads to lower stress and a reduction in fear, suggesting that blue light may improve the emotional states of fear and stress, thereby improving the welfare of poultry.

Topics: Animals; Male; Female; Chickens; Lighting; Light; Animal Welfare; Fear; Color

PubMed: 36126449
DOI: 10.1016/j.psj.2022.102052

Authors: Silvina Zabala-Travers, Mina Choi, Wei-Chung Cheng...

PURPOSE

Even though the use of color in the interpretation of medical images has increased significantly in recent years, the ad hoc manner in which color is handled and the lack of standard approaches have been associated with suboptimal and inconsistent diagnostic decisions with a negative impact on patient treatment and prognosis. The purpose of this study is to determine if the choice of color scale and display device hardware affects the visual assessment of patterns that have the characteristics of functional medical images.

METHODS

Perfusion magnetic resonance imaging (MRI) was the basis for designing and performing experiments. Synthetic images resembling brain dynamic-contrast enhanced MRI consisting of scaled mixtures of white, lumpy, and clustered backgrounds were used to assess the performance of a rainbow ("jet"), a heated black-body ("hot"), and a gray ("gray") color scale with display devices of different quality on the detection of small changes in color intensity. The authors used a two-alternative, forced-choice design where readers were presented with 600 pairs of images. Each pair consisted of two images of the same pattern flipped along the vertical axis with a small difference in intensity. Readers were asked to select the image with the highest intensity. Three differences in intensity were tested on four display devices: a medical-grade three-million-pixel display, a consumer-grade monitor, a tablet device, and a phone.

RESULTS

The estimates of percent correct show that jet outperformed hot and gray in the high and low range of the color scales for all devices with a maximum difference in performance of 18% (confidence intervals: 6%, 30%). Performance with hot was different for high and low intensity, comparable to jet for the high range, and worse than gray for lower intensity values. Similar performance was seen between devices using jet and hot, while gray performance was better for handheld devices. Time of performance was shorter with jet.

CONCLUSIONS

Our findings demonstrate that the choice of color scale and display hardware affects the visual comparative analysis of pseudocolor images. Follow-up studies in clinical settings are being considered to confirm the results with patient images.

Topics: Color; Data Display; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Signal-To-Noise Ratio; Time Factors

PubMed: 26127048
DOI: 10.1118/1.4921125