1
|
Bugden M. An investigation of the effects of topical sunscreen protection products under natural weather conditions on intrinsic color stability in maxillofacial silicones. J Indian Prosthodont Soc 2023; 23:363-372. [PMID: 37861613 DOI: 10.4103/jips.jips_339_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2023] Open
Abstract
Aim The relatively short lifespan of maxillofacial prostheses (ranging from 3-24 months) is mostly a result of colour instability of silicone elastomers caused by ultraviolet (UV) radiation, requiring frequent remakes. An improvement in colour preservation could result in fewer remakes, thus saving time and money for both clinician and patient. In the quest for a suitable colour protection method, sunscreen protection products were considered; the most recent study on this subject was carried out in 1994, albeit using a low protection factor. The aim of this research was to determine if there is value in using topical sun protection products on extraoral silicone prostheses to prevent colour degradation. Settings and Design This was an in vitro quantitative study. Materials and Methods Three commercially available sunscreen products were studied, Riemann P20, Boots Soltan, and Garnier Ambre Solaire all with a sun protection factor of 50. A total of 144 silicone elastomer samples were produced using a Caucasian (light) shade 1.2 (n = 72) and dark skin shade 3.2 (n = 72) from the Technovent Ltd. Reality Shade range. Each shade group (n = 72) was divided into three groups to be subjected to outdoor weathering (n = 24), indoor (n = 24), and dark storage (n = 24). Within each environmental group, samples were divided into groups of six samples (n = 6) to receive the three sunscreens plus a control group with no sunscreen. The CIEL* a* b* formula was used to obtain the color measurements. Statistical Analysis Used One way ANOVA test and Tukey's HSD test for multiple comparisons was used to analyse the data. Results The ΔE values had changed for all samples throughout the aging process. Conclusion Soltan showed promising results in protecting the dark-shaded samples in the outdoor environment only.
Collapse
Affiliation(s)
- Melanie Bugden
- Department of Life Sciences, Manchester Metropolitan University, Manchester; Academic Centre of Reconstructive Science, King's College London, London; Maxillofacial Prosthetics Service Department, Poole Hospital, Poole, UK
| |
Collapse
|
2
|
Kurt M, Kurt Z, Işık Ş. Using deep learning approaches for coloring silicone maxillofacial prostheses: A comparison of two approaches. J Indian Prosthodont Soc 2023; 23:84-89. [PMID: 36588380 PMCID: PMC10088445 DOI: 10.4103/jips.jips_149_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 06/14/2022] [Accepted: 06/30/2022] [Indexed: 12/31/2022] Open
Abstract
Aim This study aimed to compare the performance of two deep learning algorithms, attention-based gated recurrent unit (GRU), and the artificial neural networks (ANNs) algorithm for coloring silicone maxillofacial prostheses. Settings and Design This was an in vitro study. Materials and Methods A total of 21 silicone samples in different colors were produced with four pigments (white, yellow, red, and blue). The color of the samples was measured with a spectrophotometer, then the LFNx01, aFNx01, and bFNx01 values were recorded. The relationship between the LFNx01, aFNx01, and bFNx01 values of each sample and the amount of each pigment in the compound of the same sample was used as the training dataset, entered into each algorithm, and the prediction models were obtained. While generating the prediction model for each sample, the data of the corresponding sample assigned as the target color were excluded. LFNx01, aFNx01, and bFNx01 values of each target sample were entered into the obtained models separately, and recipes indicating the ratios for mixing the four pigments were predicted. The mean absolute error (MAE) and root mean square error (RMSE) values between the original recipe used in the production of each silicone and the recipe created by both prediction models for the same silicone were calculated. Statistical Analysis Used Data were analyzed with the Student t-test (α=0.05). Results The mean RMSE values and MAE values for the ANN algorithm (0.029 ± 0.0152 and 0.045 ± 0.0235, respectively) were found significantly higher than the attention-based GRU model (0.001 ± 0.0005 and 0.002 ± 0.0008, respectively) (P < 0.001). Conclusions Attention-based GRU model provided better performance than the ANN algorithm with respect to the MAE and RMSE values.
Collapse
Affiliation(s)
- Meral Kurt
- Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara, Turkey
| | - Zuhal Kurt
- Department of Computer Engineering, Faculty of Engineering, Atilim University, Ankara, Turkey
| | - Şahin Işık
- Department of Computer Engineering, Faculty of Engineering, Eskisehir Osmangazi University, Eskisehir, Turkey
| |
Collapse
|
3
|
Visual and instrumental color evaluation of computerized color matching system for color reproduction of maxillofacial prostheses. J Prosthet Dent 2021; 128:1121-1127. [PMID: 33663869 DOI: 10.1016/j.prosdent.2021.01.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 01/23/2021] [Accepted: 01/25/2021] [Indexed: 11/20/2022]
Abstract
STATEMENT OF PROBLEM A commercially available computerized color matching system (e-Skin) has been introduced for maxillofacial prostheses. However, studies that have tested its ability to produce an acceptable color match for skin color are lacking. PURPOSE The purpose of this clinical study was to determine the color match acceptability of light and dark skin silicone replicas fabricated with the use of the computerized color matching system. MATERIAL AND METHODS Fifteen participants with light skin and 15 participants with dark skin were recruited through personal invitation. These 30 participants (aged around 20 years) voluntarily consented to forearm skin color measurements with a spectrophotometer and a spectrocolorimeter integrated in a computerized color matching system. Silicone skin replicas for each participant were produced from the color formulations provided by the online calculator tool of the system according to the manufacturers' recommendations. The color difference between initial skin color measurements with the spectrophotometer and skin replica color measurements with the spectrophotometer for all participants was calculated by using both the CIELab (ΔE∗ab) and CIEDE2000 (ΔE00) color difference formulas. To compare the instrumental and visual evaluation of color match, 3 observers (a maxillofacial prosthodontist, a prosthodontist, and a postgraduate student) visually evaluated and rated the color match of each silicone replica on a 5-point scale. Statistical analyses were performed by using the Student t, Mann Whitney U, and chi-square tests (α=.05). RESULTS No significant differences were detected between the light and dark skin groups in terms of the ΔE∗ab and ΔE00 values obtained between the first skin color measurements and their silicone replica color measurements (P=.573, P=.338, respectively). However, a significant difference was found between light and dark skin groups for the ΔL and Δa values obtained from the same measurements (P=.031, P=.017, respectively). L∗, a∗, and b∗ values of light skin were significantly higher than those of their silicone replications (P=.008, P=.033, P=.046, respectively). Color match ratings of observers did not significantly differ when comparing the ratings of light skin replicas to ratings of dark skin replicas. CONCLUSIONS The e-Skin system provided skin replicas that matched the skin color within clinically acceptable thresholds and with ratings of at least "good" by experienced dental clinicians.
Collapse
|
4
|
Bitencourt SB, Bastos NA, Mazza LC, Rangel EC, De Souza GM, da Silva Pereira F, Goiato MC, Dos Santos DM, Pesqueira AA. Effect of handling material on mechanical and optical properties of feldspathic porcelain. J ESTHET RESTOR DENT 2020; 33:919-924. [PMID: 33045124 DOI: 10.1111/jerd.12665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 07/28/2020] [Accepted: 09/14/2020] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To evaluate the optical, chemical, and mechanical properties of feldspathic porcelain after handling with different instrument materials. MATERIAL AND METHODS Feldspathic porcelain was manipulated with different spatula compositions: metal spatula (MS), plastic spatula (PS), and glass spatula (GS) for the fabrication of 30 (n = 10) disks. Contrast ratio (CR), translucency parameter (TP), and surface Knoop microhardness (KHN) were measured. The color change (ΔE00 ) was evaluated using the CIEDE2000 system. Scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) were used for surface analysis. Data were analyzed using one-way ANOVA and Tukey test (P < 0.05). RESULTS All groups presented different morphological surfaces with higher presence of Al on the MS. PS group presented lower Al, Si, K than MS, and GS. Higher CR was observed for PS (0.734; P < 0.043), followed by MS (0.696; P < 0.043) and GS (0.65; P < 0.011). The highest TP (13.06) and KHN (386.27) were presented by GS (P < 0.001). MS and PS presented similar KHN results. The higher ΔE00 were found for plastic/metal comparison. Also, the L* values for the MS group (67.49) were lower than the other groups. CONCLUSION The use of metal spatula promoted higher color alteration during feldspathic porcelain manipulation than did the other materials. Handling with glass instrument promoted higher microhardness than other spatula materials. CLINICAL SIGNIFICANCE The effect of the material used for ceramic handling on feldspathic porcelain properties is often ignored. This study shows that the handling spatula material must be carefully chosen to avoid inadvertent changes to the feldspathic porcelain restoration.
Collapse
Affiliation(s)
- Sandro Basso Bitencourt
- Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP) School of Dentistry, Araçatuba, São Paulo, Brazil
| | - Natália Almeida Bastos
- Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Bauru, Sao Paulo, Brazil
| | - Letícia Cerri Mazza
- Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP) School of Dentistry, Araçatuba, São Paulo, Brazil
| | | | | | - Flávia da Silva Pereira
- Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP) School of Dentistry, Araçatuba, São Paulo, Brazil
| | - Marcelo Coelho Goiato
- Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP) School of Dentistry, Araçatuba, São Paulo, Brazil
| | - Daniela Micheline Dos Santos
- Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP) School of Dentistry, Araçatuba, São Paulo, Brazil
| | - Aldiéris Alves Pesqueira
- Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP) School of Dentistry, Araçatuba, São Paulo, Brazil
| |
Collapse
|
5
|
Yang H, Chen R, Attin T, Cheng H, Yu H. Repolishing in situ eroded CAD/CAM restorative materials and human enamel. J Mech Behav Biomed Mater 2020; 113:104125. [PMID: 33068923 DOI: 10.1016/j.jmbbm.2020.104125] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/26/2020] [Accepted: 09/30/2020] [Indexed: 01/01/2023]
Abstract
This study aimed to evaluate the effects of repolishing on the surface microhardness (SMH), color change (ΔE), and translucency parameter (TP) of previously in situ eroded computer-aided design/computer-aided manufacturing (CAD/CAM) restorative materials and human enamel. Each of 8 volunteers wore an intraoral appliance containing 3 CAD/CAM restorative material specimens (IPS e.max CAD lithium disilicate ceramic, Lava Ultimate hybrid ceramic, and poly (methyl methacrylate) (PMMA) block) and 1 human enamel specimen. The specimens were subjected to in situ erosion cycles by rinsing with a cola drink (4 × 5 min/day) for 14 days. After erosion, the specimens were polished with a silicone polishing system (Ceramister, Shofu Inc, Kyoto, Japan). The SMH and color of the specimens were determined at baseline (T1), after erosion (T2), and after repolishing (T3). The ΔE and TP values of the specimens were further calculated. The data were statistically analyzed using repeated-measures analysis of variance (ANOVA) and Bonferroni's test (α = 0.05). After erosion, a decrease in the SMH of the restorative materials and enamel was observed (all P < 0.001), and a decrease in the TP of the enamel was observed (P = 0.016). The ΔE values of the enamel (ΔE = 7.32) and Lava Ultimate (ΔE = 3.19) exceeded the clinically unacceptable threshold after erosion. After repolishing, the SMH of the restorative materials and enamel at T3 was significantly higher than that at T2 (all P < 0.001). No significant difference was found in the TP and ΔE values of the restorative materials and enamel between T2 and T3. In conclusion, erosion negatively affected the surface properties and appearance of the CAD/CAM restorative materials and human enamel. Repolishing contributed to restoring the compromised SMH of the eroded restorative materials and enamel to a certain extent. However, repolishing did not restore the color of the eroded restorative materials and enamel.
Collapse
Affiliation(s)
- Hui Yang
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Laboratory of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, China
| | - Run Chen
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Laboratory of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, China
| | - Thomas Attin
- Clinic of Conservative and Preventive Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Hui Cheng
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Laboratory of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, China
| | - Hao Yu
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Laboratory of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, China; Department of Applied Prosthodontics, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
| |
Collapse
|
6
|
Mine Y, Suzuki S, Eguchi T, Murayama T. Applying deep artificial neural network approach to maxillofacial prostheses coloration. J Prosthodont Res 2019; 64:296-300. [PMID: 31554602 DOI: 10.1016/j.jpor.2019.08.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 07/30/2019] [Accepted: 08/27/2019] [Indexed: 11/19/2022]
Abstract
PURPOSE Maxillofacial prosthetic rehabilitation replaces missing structures to recover the function and aesthetics relating to facial defects or injuries. Deep learning is rapidly expanding with respect to applications in medical fields. In this study, we apply the artificial neural network (ANN)-based deep learning approach to coloration support for fabricating maxillofacial prostheses. METHODS We compared two machine learning algorithms, ANN-based deep learning and the random forest algorithm, to determine the compounding amount of pigment. We prepared 52 silicone elastomer specimens of varying colors and measured the CIE 1976 L* a* b* color space information using a spectrophotometer on the input dataset. The output of these algorithms indicated the compounding amount of four pigments. According to the algorithms' pigment compounding predictions, we prepared the specimens for validation analysis and measured the CIE 1976 L* a* b* values. We determined the color differences between the real skin color of five research participants (22.3 ± 1.7 years) and that of the silicone elastomer specimens fabricated based on the algorithm predictions using the CIEDE00 ΔE00 color system. RESULTS The color differences (ΔE00 value) between the real skin color and silicone elastomer validation specimens were 3.45 ± 0.87 (ANN) and 5.54 ± 1.41 (random forest), which indicates that the deep ANN approach produced superior results with respect to the ΔE00 value compared with the random forest algorithm. CONCLUSIONS These results suggest that applying deep ANN is a promising technique for the coloration of maxillofacial prostheses.
Collapse
Affiliation(s)
- Yuichi Mine
- Department of Medical System Engineering, Division of Oral Health Sciences, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi Minami-ku, Hiroshima 734-8553, Japan; Translational Research Center, Hiroshima University, 1-2-3 Kasumi Minami-ku, Hiroshima 734-8553, Japan.
| | - Shunsuke Suzuki
- Department of Medical System Engineering, Division of Oral Health Sciences, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi Minami-ku, Hiroshima 734-8553, Japan
| | - Toru Eguchi
- Graduate School of Engineering, Hiroshima University, 1-3-2 Kagamiyama, Higashi-hiroshima 739-0046, Japan
| | - Takeshi Murayama
- Department of Medical System Engineering, Division of Oral Health Sciences, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi Minami-ku, Hiroshima 734-8553, Japan
| |
Collapse
|
7
|
Karakoca Nemli S, Bankoğlu Güngör M, Bağkur M, Turhan Bal B, Kasko Arıcı Y. In vitro evaluation of color and translucency reproduction of maxillofacial prostheses using a computerized system. J Adv Prosthodont 2018; 10:422-429. [PMID: 30584471 PMCID: PMC6302083 DOI: 10.4047/jap.2018.10.6.422] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 10/10/2018] [Accepted: 11/18/2018] [Indexed: 11/29/2022] Open
Abstract
PURPOSE Accurate color matching of maxillofacial prostheses to skin is important for esthetics. A computerized color matching system specific to human skin has recently been developed. The purpose of this study was to evaluate the accuracy in color and translucency matching of the computerized color matching system across different skin colors. MATERIALS AND METHODS The silicone was colored to simulate 28 different skin colors (n=5) to serve as “target skin colors”. Using a spectrocolorometer (e-skin), color codes were determined for “replicate skin color” fabrication. CIELAB Delta-E between target skin color-replicate skin color pairs and translucency parameter were calculated. CIELAB Delta-E values were compared with one-way ANOVA and Tukey multiple-comparison. The agreement between L*, a*, b* and translucency parameter of target skin colors and replicate skin color were calculated by a two-way mixed average measures intraclass correlation coefficient. Translucency parameter of target skin color-replicate skin color pairs were compared with Paired t-test (α=.05). RESULTS The mean CIELAB Delta-E value was 3.83 and significant differences were found among colors. The intraclass correlation coefficient showed excellent reliability for L*, a*, b* and good reliability for translucency parameter (P<.001). The mean translucency parameter of replicate skin colors was significantly higher than that of translucency parameter. CONCLUSION The computerized color matching system specific to human skin was found to be reliable in terms of color and translucency between target skin colors and replicate skin color.
Collapse
Affiliation(s)
- Seçil Karakoca Nemli
- Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara, Turkey
| | | | - Meral Bağkur
- Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara, Turkey
| | - Bilge Turhan Bal
- Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara, Turkey
| | - Yeliz Kasko Arıcı
- Biostatistics and Medical Informatics Department, Faculty of Medicine, Ordu University, Ordu, Turkey
| |
Collapse
|
8
|
Effect of vulcanization temperature and dental stone colour on colour degradation of maxillofacial silicone elastomers. BMC Oral Health 2017; 17:72. [PMID: 28359311 PMCID: PMC5374663 DOI: 10.1186/s12903-017-0365-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 03/24/2017] [Indexed: 02/08/2023] Open
Abstract
Background Colour degradation is a major problem in maxillofacial silicone elastomers. Recent studies have focused on colour stability and the mechanical properties of the silicone elastomers. A colour match is also essential for the acceptance of the prosthesis by the patient. The aim of this study is to assess the colour degradation of the silicone elastomer after being moulded in different colours of dental stones at two different vulcanization temperatures. Methods Five different colours of dental stones were used to fabricate a total of 120 silicone blocks using a Cosmesil M511 maxillofacial silicone elastomer. Vulcanization was completed at two different temperatures (25 and 100° Celsius). Colour measurements were obtained with a Conica Minolta spectrophotometer. The CIEDE2000 formula was used to calculate the colour differences (∆E00). Two-way ANOVA, one-way ANOVA with Bonferroni corrected post-hoc p values and independent samples t-test were used for the statistical analyses. Results High temperature vulcanization causes lightening of the maxillofacial silicone elastomers without regard to the dental stone colour (p = 0.001). Specimens moulded in green stone lightened least at room temperature (p = 0.999). Compared to the control group, at high temperature, all specimens moulded in coloured dental stones darkened significantly (p < 0.001 for white, blue and yellow; p = 0.006 for green; p = 0.045 for reddish-brown). In the high temperature group, the shift to a green chroma was significant in the white, yellow and green dental stones groups (p = 0.001, p = 0.002, p < 0.001, respectively). The mean b* of the high temperature control group was higher than that of the room temperature control group (p < 0.001). The only ∆E00 score lower than the perceptibility threshold for dental materials (∆E00 = 1.30) was between the room temperature control group and the room temperature green dental stone group (∆E00 = 0.96). Conclusions Green and blue dental stones cause less colour degradation in silicone elastomers. Reddish-brown dental stones cause the most colour degradation in silicone elastomers. At 100 °C, the colour of the silicone elastomer lightens and yellows even if the elastomer is vulcanized in a stainless steel mould. White, yellow and reddish-brown dental stones make the silicone elastomer appear more yellow even if the elastomer is vulcanized at room temperature.
Collapse
|
9
|
Effect of different acidic solutions on the optical behavior of lithium disilicate ceramics. J Prosthet Dent 2017; 118:430-436. [PMID: 28222886 DOI: 10.1016/j.prosdent.2016.10.023] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 10/21/2016] [Accepted: 10/21/2016] [Indexed: 11/22/2022]
Abstract
STATEMENT OF PROBLEM The stability of the optical characteristics of dental ceramics is essential. Degradation of these materials resulting from pH or temperature alterations in the oral cavity can lead to treatment failure. PURPOSE The purpose of this in vitro study was to evaluate the color change (ΔE), the L* coordinate, the translucency parameter, and the contrast ratio of lithium disilicate ceramic exposed to commonly used and potentially colorant solutions. MATERIAL AND METHODS Fifty lithium disilicate specimens were prepared and divided into 5 groups according to the immersion solution (artificial saliva, orange juice, cola, coffee, and red wine). Immersions in acidic beverages were alternated in a thermocycler with artificial saliva. The control group was immersed in artificial saliva at 37°C throughout the immersion period. After 168 hours of immersion, the color parameters were assessed with a spectrophotometer and calculated using the because system on 2 backgrounds (black and white) and in 2 time periods, before thermocycling and after thermocycling. Data were submitted to analysis of variance followed by the Tukey honest significant difference test (α=.05). RESULTS Greater color change (ΔE) and lower L* coordinate values were observed after immersion in orange juice and cola. Regarding the translucency parameter and contrast ratio, the immersion in coffee resulted in greater opacity and lower translucency of the material. CONCLUSIONS Alterations in the color stainability, the L* coordinate values, the translucency parameter, and the contrast ratio of the lithium disilicate ceramic were observed, according to the acidic solutions tested.
Collapse
|
10
|
Nogueira AD, Della Bona A. The effect of a coupling medium on color and translucency of CAD–CAM ceramics. J Dent 2013; 41 Suppl 3:e18-23. [DOI: 10.1016/j.jdent.2013.02.005] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2012] [Revised: 02/05/2013] [Accepted: 02/11/2013] [Indexed: 10/27/2022] Open
|
11
|
Hungerford E, Beatty MW, Marx DB, Simetich B, Wee AG. Coverage error of commercial skin pigments as compared to human facial skin tones. J Dent 2013; 41:986-91. [PMID: 23907084 DOI: 10.1016/j.jdent.2013.07.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 07/15/2013] [Accepted: 07/18/2013] [Indexed: 10/26/2022] Open
Abstract
OBJECTIVES It is unknown if present-day pigments used for intrinsic colouration of maxillofacial prostheses are representative of human facial skin tones. This study's purpose was to measure L*a*b* values of pigmented elastomers coloured by eleven skin tone pigments and determine coverage error (CE) when the pigments were compared to human facial lip and nose colour data. METHODS 11 skin tone pigments were combined at 0.1%, 1% and 10% by weight with A-2186 elastomer (n=3). L*a*b* values were measured with a spectrophotometer and group means were used to calculate ΔE* colour differences with each L*a*b* value obtained for human nose and lip. Pigmented elastomer CEs were calculated for nose and lip. Results were compared to CEs for proposed shade guide colours obtained from clustering analyses of facial skin colours. RESULTS L* values of pigmented elastomers generally were higher than those measured for nose and lip, whereas a* values were lower. CEs for pigmented elastomers were higher than those obtained from the proposed shade guide obtained from clustered skin measurements. CONCLUSIONS Overall, the current commercial elastomers appeared to be too white and not red enough to adequately match the skin tones of the subject population. Adjustments must be made to the existing pigmenting system in order to adequately match the skin colours of the study population. CLINICAL SIGNIFICANCE The creation of a shade guide and a collection of intrinsic pigments representing the realm of human facial skin colours would greatly decrease the time a patient must sit while the clinician is obtaining an acceptable colour match for the silicone to be used for processing the final prosthesis, thereby increasing both patient satisfaction and clinician productivity.
Collapse
Affiliation(s)
- Elizabeth Hungerford
- University of Nebraska Medical Center College of Dentistry, 40th & Holdrege, Lincoln, NE 68583-0740, USA
| | | | | | | | | |
Collapse
|
12
|
Han Y, Powers JM, Kiat-amnuay S. Effect of opacifiers and UV absorbers on pigmented maxillofacial silicone elastomer, part 1: Color stability after artificial aging. J Prosthet Dent 2013; 109:397-401. [DOI: 10.1016/s0022-3913(13)60327-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
13
|
Pesqueira AA, Goiato MC, Dos Santos DM, Haddad MF, Moreno A. Effect of disinfection and accelerated ageing on dimensional stability and detail reproduction of a facial silicone with nanoparticles. J Med Eng Technol 2012; 36:217-21. [DOI: 10.3109/03091902.2012.666321] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|