To develop a customized CIELAB-based whiteness index for dentistry that accurately correlates to ... more To develop a customized CIELAB-based whiteness index for dentistry that accurately correlates to perception of tooth whiteness. Four psychophysical experiments (PE1-4) were conducted by three panels of observers (OP1-3) under diffuse/0° observation/measuring conditions and under typical clinical viewing conditions. Nine whiteness indices (WI, Z%, WIC, WIO, W31, W64, W, WLAB, W*), two yellowness indices (YID1925, YIE313) and tint of white in the CIELAB color system (T) were compared with regard to their ability to measure the perceived whiteness of human teeth. Determination coefficient (R(2)) and '% wrong decision' (%WD) method were used as direct measures of the quality of the indices for whiteness perception in dentistry. CIELAB-based whiteness index (WID=0.511L* -2.324a* -1.100b*) was developed through optimization from the data obtained in PE1. The proposed WID performed better than all the CIELAB and CIE1931 XYZ-based indices under laboratory and clinical conditions (only WIO was comparable to WID in PE2 and PE4). The validation experiments under laboratory and typical clinical conditions revealed that the proposed index WID outperformed previous indices, being the only CIELAB-based index developed for evaluation of whiteness in dentistry.
The aim of this study is to compile a comprehensive database on color range and color distributio... more The aim of this study is to compile a comprehensive database on color range and color distribution of healthy human gingiva by age, gender and ethnicity. Spectral reflection of keratinized gingiva at upper central incisors was measured by spectroradiometer and converted into CIELAB values. Lightness range (ΔL*) for all groups together was 26.8. Corresponding a* (green-red) and b* (blue-yellow) ranges (Δa* and Δb*) were 18.3 and 13.0. Significant differences (p < 0.05) were recorded by age for L* and a* coordinates, by gender for b* coordinate, and by ethnicity for L*, a* and b* coordinates. R(2)-values between color coordinates were 0.01 (L*/a*), 0.03 (L*/b*), and 0.12 (a*/b*). The smallest color differences were recorded between age groups 46-60 and 60 + (ΔE* = 0.9), and between Caucasians and Hispanics (ΔE* = 1.1). Color difference by gender was 1.3. When total L*a*b* ranges were divided into four equal segments, 51.7% of subjects had L* value within the third segment (from lig...
The aim of this study was to analyze color parameters and color compatibility of two randomly cho... more The aim of this study was to analyze color parameters and color compatibility of two randomly chosen Vita shade guides, as well as to propose possible clinical guidelines. Data were recorded using a colorimeter set to standard illuminant source C and the CIE L*a*b* system. A custom adapter system, which allowed a measuring area at the middle third of the tabs, was produced. Each of 42 tabs was recorded one time each on three different days. Color distribution was examined in diagrams whose coordinates were L*a*b* and L*C*H degree color coordinate pairs. Color coordinate ranges and coverage error were examined using the corresponding equations and statistical methods. The method repeatability was approximately delta E* = 0.1. Color difference ranges of Vitapan Classical and Vitapan 3D Master were 14.3 and 19.2, respectively. Color coordinate ranges of Vitapan Classical were as follows: delta L* = 12.8; delta a* = 1.7; delta b* = 9.0; delta C* = 9.0; and delta H degree = 7.4. Corresponding values for Vitapan 3D Master were delta L* = 15.3; delta a* = 3.4; delta b* = 16.3; delta C* = 16.6; and delta H degree = 10.5. Coverage error of Vitapan 3D Master to Vitapan Classical was 1.4 +/- 0.6, while vice versa it was 2.0 +/- 1.5. Compared to Vitapan Classical, chromaticity ranges of Vitapan 3D Master were extended in the desired directions: hue was extended toward yellow-red, and saturation was extended toward more saturated tabs. Compared to Vitapan Classical, Vitapan 3D Master tabs were more uniformly spaced. The examined shade guides were found to be color compatible.
... two of the studies that dem-onstrated lower conversion values were using experimental LeD lig... more ... two of the studies that dem-onstrated lower conversion values were using experimental LeD lights.4, 5 the experimental LeD light used by tarle et al.5 ... as noted previ-ously in this review, the e-Light was not used at maximum power which could have an influ-enced the results. ...
This study evaluated a newly developed visual shade-matching apparatus, Shademat Visual+, as well... more This study evaluated a newly developed visual shade-matching apparatus, Shademat Visual+, as well as the influence of tab arrangement, clinician gender, and years in practice on shade-matching quality. A group of 129 color-normal evaluators-dental students and general dentists-matched the shade of four ceramometal crowns using the Vitapan Classical shade guide. Crowns were positioned onto the upper member of an artificial head and fastened to the headrest of the dental chair or Shademat Visual+. Shade tabs were arranged according to the manufacturer&amp;amp;amp;amp;amp;amp;amp;amp;#39;s suggestion or according to deltaE* in relation to the &amp;amp;amp;amp;amp;amp;amp;amp;quot;lightest&amp;amp;amp;amp;amp;amp;amp;amp;quot; tab and divided into groups (alternative arrangement). The evaluators matched the shade of four ceramometal crowns both in daylight and using the Shademat Visual+ artificial light source. The color coordinates were determined using digital image analysis. Based on deltaE* values, each shade-matching result was ranked from 1 (the worst match) to 16 (the best match) points. The evaluators achieved a better result in Shademat Visual+ trials than in daylight trials (13.2 points vs 12.4 points; P &amp;amp;amp;amp;amp;amp;amp;amp;lt; .001). For the same ceramometal crown, 12.7 points were recorded in daylight trials with the manufacturer-suggested arrangement, and 13.7 were recorded with the alternative arrangement (P&amp;amp;amp;amp;amp;amp;amp;amp;lt; .001). Corresponding values for Shademat Visual+ trials were 13.6 points and 14.6 points, respectively (P&amp;amp;amp;amp;amp;amp;amp;amp;lt; .001). Female-male and student-dentist evaluator differences were not significant. The Shademat Visual+ apparatus enabled better shade-matching results than daylight. The alternative tab arrangement enabled better results than the manufacturer-suggested one. Gender and years in practice did not influence shade-matching quality.
Objective: To evaluate the accelerated aging effects on color of different composite resins. Meth... more Objective: To evaluate the accelerated aging effects on color of different composite resins. Method: Shades were selected from two flowable composites, A1, A3, and White (WH), Filtek Supreme Ultra Flowable/3M ESPE (FSU); A1, A3 and Bleach (BL), Tetric EvoFlow/Ivoclar Vivadent (TEF), and A1, A3, and B1 micro-hybrid control (Filtek Z250/3M ESPE). Disc shaped specimens (10 mm X 2 mm, n=60) were polymerized using a halogen curing light (Demetron 501, Kerr/Demetron) for 40 seconds. Specimens were finished using 400-grit SiC paper and polished with a one-step polisher (PoGo, Dentsply/Caulk) for 40 seconds. Color measurements were taken at baseline (after 24 hour-storage in distilled water at 37°C) using a spectrophometer (Color-Eye 7000, GretagMacbeth) and after exposure to accelerated aging (150 kJ/m2) in a Weather-ometer (Ci35A, Atlas). Means and standard deviations were determined. The data were analyzed by analysis of variance. Fisher's PLSD intervals at a 0.05 level of significan...
Objectives To assess the color stability of high-strength acrylic resin denture teeth after expos... more Objectives To assess the color stability of high-strength acrylic resin denture teeth after exposure to red wine, coffee and artificial ageing. Methods Four different shades of acrylic resin denture teeth were selected from three manufacturers. The teeth were evaluated in two phases: Phase I, upon staining for 7 days in distilled water (control Group A), red wine (experimental Group B) and coffee (experimental Group C), and Phase II, upon artificial ageing in a Weather-Ometer for a total exposure of 150 kJ/m2 (control Group A; Phase I). Denture tooth positioning jigs were fabricated and color data recorded by means of an intra-oral spectrophotometer and expressed using the Commission Internationale d’Eclairage (CIE) L*a*b* color notation system. Means and standard deviations were determined. The staining data were analysed by three-way ANOVA, while the artificial ageing data were analysed by two-way ANOVA. Fisher's PLSD intervals were calculated at a significance level of P ≤ 0....
Objectives: To create computer models of gingival shade guides based on the initial sample of 69 ... more Objectives: To create computer models of gingival shade guides based on the initial sample of 69 participants, using Agglomerative Hierarchical Clustering and Fuzzy C Means clustering Methods: A total of 69 subjects of both genders and all ethnicities, were recruited. All subjects were age 18 or above and had healthy gingiva above upper central incisors. Spectral reflection of the keratinized gingiva 2-3 mm apical to the free gingival margin was measured using a spectroradiometer. Anonymized data were converted into CIELAB values and analyzed. Two models of gingival shade guide, each containing 1 to 10 tabs, were designed using A) Agglomerative Hierarchical Clustering (AHC), and B) Fuzzy C Means Clustering (FCM) technique. Coverage error (DE*COV) was calculated for each of model shade guides. Wilcoxon signed rank test was used to compare two clustering algorithms as related to differences in coverage errors obtained for different number of clusters. A 50:50% acceptability threshold ...
Objectives: The goal of the study was to determine the current status of the teaching of color in... more Objectives: The goal of the study was to determine the current status of the teaching of color in dental education at undergraduate level in United States (USA) and Germany (GER). Methods: A cross-sectional web-based survey, containing 27 multiple choice, multiple best and single best answers, was created. Upon receiving IRB approval, dental faculty involved in the teaching of color to undergraduate dental students in USA and GER (N=121), were administered. Statistical analysis of differences between Pre-D and Post-D was performed using Fisher's Exact Test (a=0.05). Results: A total of 49 responses were received (response rate 40.5%); There were 34 responses from USA and 15 from GER. A course on color or color in dentistry was included in the dental curriculum of 73.5 of US programs and 80% of GER programs. The number of hours dedicated to color-related topics was 4.02.4 and 3.7249 for USA and GER, respectively. The following topics were frequently taught in both countries: colo...
To develop a customized CIELAB-based whiteness index for dentistry that accurately correlates to ... more To develop a customized CIELAB-based whiteness index for dentistry that accurately correlates to perception of tooth whiteness. Four psychophysical experiments (PE1-4) were conducted by three panels of observers (OP1-3) under diffuse/0° observation/measuring conditions and under typical clinical viewing conditions. Nine whiteness indices (WI, Z%, WIC, WIO, W31, W64, W, WLAB, W*), two yellowness indices (YID1925, YIE313) and tint of white in the CIELAB color system (T) were compared with regard to their ability to measure the perceived whiteness of human teeth. Determination coefficient (R(2)) and &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;% wrong decision&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; (%WD) method were used as direct measures of the quality of the indices for whiteness perception in dentistry. CIELAB-based whiteness index (WID=0.511L* -2.324a* -1.100b*) was developed through optimization from the data obtained in PE1. The proposed WID performed better than all the CIELAB and CIE1931 XYZ-based indices under laboratory and clinical conditions (only WIO was comparable to WID in PE2 and PE4). The validation experiments under laboratory and typical clinical conditions revealed that the proposed index WID outperformed previous indices, being the only CIELAB-based index developed for evaluation of whiteness in dentistry.
The aim of this study is to compile a comprehensive database on color range and color distributio... more The aim of this study is to compile a comprehensive database on color range and color distribution of healthy human gingiva by age, gender and ethnicity. Spectral reflection of keratinized gingiva at upper central incisors was measured by spectroradiometer and converted into CIELAB values. Lightness range (ΔL*) for all groups together was 26.8. Corresponding a* (green-red) and b* (blue-yellow) ranges (Δa* and Δb*) were 18.3 and 13.0. Significant differences (p < 0.05) were recorded by age for L* and a* coordinates, by gender for b* coordinate, and by ethnicity for L*, a* and b* coordinates. R(2)-values between color coordinates were 0.01 (L*/a*), 0.03 (L*/b*), and 0.12 (a*/b*). The smallest color differences were recorded between age groups 46-60 and 60 + (ΔE* = 0.9), and between Caucasians and Hispanics (ΔE* = 1.1). Color difference by gender was 1.3. When total L*a*b* ranges were divided into four equal segments, 51.7% of subjects had L* value within the third segment (from lig...
The aim of this study was to analyze color parameters and color compatibility of two randomly cho... more The aim of this study was to analyze color parameters and color compatibility of two randomly chosen Vita shade guides, as well as to propose possible clinical guidelines. Data were recorded using a colorimeter set to standard illuminant source C and the CIE L*a*b* system. A custom adapter system, which allowed a measuring area at the middle third of the tabs, was produced. Each of 42 tabs was recorded one time each on three different days. Color distribution was examined in diagrams whose coordinates were L*a*b* and L*C*H degree color coordinate pairs. Color coordinate ranges and coverage error were examined using the corresponding equations and statistical methods. The method repeatability was approximately delta E* = 0.1. Color difference ranges of Vitapan Classical and Vitapan 3D Master were 14.3 and 19.2, respectively. Color coordinate ranges of Vitapan Classical were as follows: delta L* = 12.8; delta a* = 1.7; delta b* = 9.0; delta C* = 9.0; and delta H degree = 7.4. Corresponding values for Vitapan 3D Master were delta L* = 15.3; delta a* = 3.4; delta b* = 16.3; delta C* = 16.6; and delta H degree = 10.5. Coverage error of Vitapan 3D Master to Vitapan Classical was 1.4 +/- 0.6, while vice versa it was 2.0 +/- 1.5. Compared to Vitapan Classical, chromaticity ranges of Vitapan 3D Master were extended in the desired directions: hue was extended toward yellow-red, and saturation was extended toward more saturated tabs. Compared to Vitapan Classical, Vitapan 3D Master tabs were more uniformly spaced. The examined shade guides were found to be color compatible.
... two of the studies that dem-onstrated lower conversion values were using experimental LeD lig... more ... two of the studies that dem-onstrated lower conversion values were using experimental LeD lights.4, 5 the experimental LeD light used by tarle et al.5 ... as noted previ-ously in this review, the e-Light was not used at maximum power which could have an influ-enced the results. ...
This study evaluated a newly developed visual shade-matching apparatus, Shademat Visual+, as well... more This study evaluated a newly developed visual shade-matching apparatus, Shademat Visual+, as well as the influence of tab arrangement, clinician gender, and years in practice on shade-matching quality. A group of 129 color-normal evaluators-dental students and general dentists-matched the shade of four ceramometal crowns using the Vitapan Classical shade guide. Crowns were positioned onto the upper member of an artificial head and fastened to the headrest of the dental chair or Shademat Visual+. Shade tabs were arranged according to the manufacturer&amp;amp;amp;amp;amp;amp;amp;amp;#39;s suggestion or according to deltaE* in relation to the &amp;amp;amp;amp;amp;amp;amp;amp;quot;lightest&amp;amp;amp;amp;amp;amp;amp;amp;quot; tab and divided into groups (alternative arrangement). The evaluators matched the shade of four ceramometal crowns both in daylight and using the Shademat Visual+ artificial light source. The color coordinates were determined using digital image analysis. Based on deltaE* values, each shade-matching result was ranked from 1 (the worst match) to 16 (the best match) points. The evaluators achieved a better result in Shademat Visual+ trials than in daylight trials (13.2 points vs 12.4 points; P &amp;amp;amp;amp;amp;amp;amp;amp;lt; .001). For the same ceramometal crown, 12.7 points were recorded in daylight trials with the manufacturer-suggested arrangement, and 13.7 were recorded with the alternative arrangement (P&amp;amp;amp;amp;amp;amp;amp;amp;lt; .001). Corresponding values for Shademat Visual+ trials were 13.6 points and 14.6 points, respectively (P&amp;amp;amp;amp;amp;amp;amp;amp;lt; .001). Female-male and student-dentist evaluator differences were not significant. The Shademat Visual+ apparatus enabled better shade-matching results than daylight. The alternative tab arrangement enabled better results than the manufacturer-suggested one. Gender and years in practice did not influence shade-matching quality.
Objective: To evaluate the accelerated aging effects on color of different composite resins. Meth... more Objective: To evaluate the accelerated aging effects on color of different composite resins. Method: Shades were selected from two flowable composites, A1, A3, and White (WH), Filtek Supreme Ultra Flowable/3M ESPE (FSU); A1, A3 and Bleach (BL), Tetric EvoFlow/Ivoclar Vivadent (TEF), and A1, A3, and B1 micro-hybrid control (Filtek Z250/3M ESPE). Disc shaped specimens (10 mm X 2 mm, n=60) were polymerized using a halogen curing light (Demetron 501, Kerr/Demetron) for 40 seconds. Specimens were finished using 400-grit SiC paper and polished with a one-step polisher (PoGo, Dentsply/Caulk) for 40 seconds. Color measurements were taken at baseline (after 24 hour-storage in distilled water at 37°C) using a spectrophometer (Color-Eye 7000, GretagMacbeth) and after exposure to accelerated aging (150 kJ/m2) in a Weather-ometer (Ci35A, Atlas). Means and standard deviations were determined. The data were analyzed by analysis of variance. Fisher's PLSD intervals at a 0.05 level of significan...
Objectives To assess the color stability of high-strength acrylic resin denture teeth after expos... more Objectives To assess the color stability of high-strength acrylic resin denture teeth after exposure to red wine, coffee and artificial ageing. Methods Four different shades of acrylic resin denture teeth were selected from three manufacturers. The teeth were evaluated in two phases: Phase I, upon staining for 7 days in distilled water (control Group A), red wine (experimental Group B) and coffee (experimental Group C), and Phase II, upon artificial ageing in a Weather-Ometer for a total exposure of 150 kJ/m2 (control Group A; Phase I). Denture tooth positioning jigs were fabricated and color data recorded by means of an intra-oral spectrophotometer and expressed using the Commission Internationale d’Eclairage (CIE) L*a*b* color notation system. Means and standard deviations were determined. The staining data were analysed by three-way ANOVA, while the artificial ageing data were analysed by two-way ANOVA. Fisher's PLSD intervals were calculated at a significance level of P ≤ 0....
Objectives: To create computer models of gingival shade guides based on the initial sample of 69 ... more Objectives: To create computer models of gingival shade guides based on the initial sample of 69 participants, using Agglomerative Hierarchical Clustering and Fuzzy C Means clustering Methods: A total of 69 subjects of both genders and all ethnicities, were recruited. All subjects were age 18 or above and had healthy gingiva above upper central incisors. Spectral reflection of the keratinized gingiva 2-3 mm apical to the free gingival margin was measured using a spectroradiometer. Anonymized data were converted into CIELAB values and analyzed. Two models of gingival shade guide, each containing 1 to 10 tabs, were designed using A) Agglomerative Hierarchical Clustering (AHC), and B) Fuzzy C Means Clustering (FCM) technique. Coverage error (DE*COV) was calculated for each of model shade guides. Wilcoxon signed rank test was used to compare two clustering algorithms as related to differences in coverage errors obtained for different number of clusters. A 50:50% acceptability threshold ...
Objectives: The goal of the study was to determine the current status of the teaching of color in... more Objectives: The goal of the study was to determine the current status of the teaching of color in dental education at undergraduate level in United States (USA) and Germany (GER). Methods: A cross-sectional web-based survey, containing 27 multiple choice, multiple best and single best answers, was created. Upon receiving IRB approval, dental faculty involved in the teaching of color to undergraduate dental students in USA and GER (N=121), were administered. Statistical analysis of differences between Pre-D and Post-D was performed using Fisher's Exact Test (a=0.05). Results: A total of 49 responses were received (response rate 40.5%); There were 34 responses from USA and 15 from GER. A course on color or color in dentistry was included in the dental curriculum of 73.5 of US programs and 80% of GER programs. The number of hours dedicated to color-related topics was 4.02.4 and 3.7249 for USA and GER, respectively. The following topics were frequently taught in both countries: colo...
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