Tooth Color Matching Research Articles

Digital Photocolorimetric Analysis of In Vitro Tooth Color Changes.

Tooth color matching is challenging, and digital photocolorimetry using eLABor_aid (eLAB) provides objective evaluation through polarized photographs. However, its comparability with spectrophotometry remains unclear. Bovine incisor root canals (n=30) were prepared to simulate an incomplete root apex. The teeth were randomly assigned to three groups based on intracanal medication: control (without medication); calcium hydroxide/propylene glycol; and triple-antibiotic paste (n=10 each). Tooth color was assessed using both eLAB and spectrophotometry. Measurements were taken at the crown medio-cervical region on five-time intervals (baseline, 1, 3, 7, and 14 days). Statistical analysis included two-way repeated-measures ANOVA, Sidak post hoc and Pearson's correlation test (α=0.05). No significant differences were observed between the two methods for either medication or follow-ups (p>0.05). Triple-antibiotic paste exhibited higher color variation (p<0.05). After 7 days, all groups presented significant color changes (p<0.05). Moderate to high correlations (R2 from 0.51 to 0.84, p<0.0001) were found between both methods for all groups at all intervals. The eLAB is a reliable method for detecting tooth color changes, and its results are comparable to spectrophotometry analysis.

Clinical Tooth Color Matching: In Vivo Comparisons of Digital Photocolorimetric and Spectrophotometric Analyses.

This study aimed to compare the tooth color matching of two dental colorimetric methods: the spectrophotometric analysis (SPM) and the standardized digital photocolorimetric analysis (DPC). The color of 60 maxillary central incisors of 30 volunteers (22.5 ± 7.6 years) was analyzed. In the DPC method, tooth photographs were standardized with the eLABor_aid protocol, processed with Adobe Photoshop Lightroom software, and the values of L*, a*, and b* were obtained with a Digital Color Meter software. For the SPM, L*, a*, and b* were measured directly with a handheld spectrophotometer. Data were submitted to paired t-test and Pearson correlation test (α=0.05). Mean color difference between the two methods was calculated with CIELAB formula. All color coordinates revealed different values when comparing DPC to SPM in the same tooth (p<0.0001). Mean color difference (ΔEab) between SPM and DPC was 11.5 ±3.1. A positive correlation was observed for L* (R2=0.73,p<0.0001), a* (R2=0.31, p=0.017), and b* (R2=0.83, p<0.0001). Even though the color coordinate values were different in both methods, they were correlated, revealing that the DPC is a viable alternative to determine the tooth color matching.

EFFECTS OF THREE-DIMENSIONAL-PRINTED ZIRCONIA ALL-CERAMIC CROWNS ON PERIODONTAL HEALTH AND AESTHETICS OF PATIENTS RECEIVING ANTERIOR TOOTH AESTHETIC RESTORATION

The aim of this study was to evaluate the effects of three-dimensional (3D)-printed zirconia all-ceramic crowns on the periodontal tissues and aesthetics of patients receiving anterior tooth aesthetic restoration. A total of 85 patients with anterior tooth defects treated from January 2018 to October 2019 were selected. We studied zirconia all-ceramic crowns made by computer-aided design and computer-aided manufacturing (CAD/CAM) (control group) and 3D printing (observation group). The short-term restoration effects, periodontal health indices, functional recovery, long-term clinical efficacy and aesthetic effects were compared. The gingival marginal fitness of the observation group was better than that of the control group, but the control group had better tooth color matching (P &lt; 0.05). One year after the restoration, the bleeding index, probing depth, attachment loss, gingival index and plaque index all declined in the two groups, particularly in the observation group. Both the masticatory and language functions were improved in the two groups, especially in the observation group (P &lt; 0.05). Both 3D-printed and CAD/CAM zirconia all-ceramic crowns have better cosmetic restoration effects on the anterior teeth. However, 3D-printed zirconia all-ceramic crowns have better gingival marginal fitness, which can benefit the periodontal tissue recovery, relieve gingival inflammation, and improve masticatory and language functions.

The effects of age on tooth color and of viewing distance on visual tooth color matching in aesthetic dentistry

Aim: This study aims to question the effect of visual distance on color selection by scoring the maxillary central tooth color with the visual color selection method and to investigate the relationship between tooth color and patient age. Methodology: Maxillary central tooth color was determined by a single operator using visual methods from two different distances, 35 cm and 70 cm, in a total of 100 people between the ages of 20-80 and of different genders. The value, hue and ages of the teeth were recorded using the VITA Toothguide 3D-MASTER color scale at 2 different viewing distances. Visual color selection was made in natural daylight, preferably between 10:00 and 12:00 in the morning. Subjects were observed at eye level, and all color assessments were performed rapidly (5-7 s). Independent T-test was used for independent groups and Chi-square test was used for dependent groups. Results: Considering the relationship of lightness with distance, there is a significant difference between the values ​​at 35 cm and 70 cm distances. It was observed that the lightness increased when the measurements made from 70 cm were compared with the measurements made from 35 cm. As the age increases, the ratio of the brightness value of 1, which is the highest lightness, decreases, and the ratio of the darker 3 and 4 lightness​​increases. R (reddish) hue was found to be higher in the 40-59 and over 60 age groups compared to the 20-39 age group. Conclusion: It was observed that the tooth color was determined lighter in the measurements made from 70 cm compared to the measurements made from 35 cm. It is important to determine the color at 35 cm so that the incorrect lightness (value) is not selected. It can be said that as the age increases, the tooth gets darker and the reddish and yellowish hue increases. How to cite this article: Kızılırmak B, Güntekin N, Tunçdemir AR. The effects of age on tooth color and of viewing distance on visual tooth color matching in aesthetic dentistry. Int Dent Res 2022;12(Suppl.1):29-33. https://doi.org/10.5577/intdentres.442 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Evaluation of accuracy and characteristics of tooth-color matching by intraoral scanners based on Munsell color system: an in vivo study.

To compare the accuracy of visual and instrumental methods for tooth-color matching based on three attributes in the Munsell color system and to investigate the characteristics of intraoral scanners for tooth-color matching. Shades of the cervical, middle, and incisal third region of 130 maxillary anterior teeth were matched visually by an experienced prosthodontist (EP) using Vita classical A1-D4 (VC) and Vita System3D-Master (V3D) shade guides, and digitally by a spectrophotometer (Vita Easyshade V, VE) and two intraoral scanners (3Shape TRIOS 3, T3; TRIOS 4, T4). VE was used as a reference. The reproducibility of the three test groups was examined by repeating the measurements in triplicate. The overall trueness of the three test groups (from high to low) was T3 > EP > T4 for VC values (p < 0.01), and T3, EP > T4 (p < 0.01) for V3D. The trueness of T3 in incisal regions was lower than cervical and middle regions. When hue or lightness was correct, the mismatched chroma in test groups was smaller than VE (p < 0.01). The repeatability of EP was the poorest (p < 0.01). The color-matching trueness of T3 was higher than EP and T4. The reproducibility of intraoral scanners was better than visual methodology.

Assessment Of Factors Involved In The Visual Choice Of Dental Color - Clinical Trials

With the development of societies, the demands of patients in terms of dental aesthetics have increased. To keep up with the increasingly demanding requirements of patients, dentists have been researching the factors that influence positively or negatively the choice of dental color, in order to control them and to obtain the best aesthetic results.Purpose of the study:Whether there is a correlation between choice time and accuracy. Whether there are differences in time and accuracy in determining with the Vita Classical key compared to the Vita Linear Guide.Material and Methods:This study involved 30 students (10 males and 20 females) of the University of Medicine and Pharmacy Iuliu Hațieganu ClujNapoca from the second to sixth year of study, aged 19-26. Of these, 18 (5 males and 13 females) were included and participated in the study itself. The participants were asked to determine the dental color of 1.1; 1.2; 1.3 of a patient. Results:In all three teeth color, both with the Vita Classical key and with the Vita Linear Guide key, no statistically significant correlation was found between the tooth color matching time and the matching accuracy. Conclusions: 1. A3 color required a longer matching time than A2 and A3.5, however the differences were not statistically significant. 2M2 also required a longer determination time than 3M2, but the differences were not statistically significant. 2. No correlation was found between the time required to determine a color and the accuracy of its determination.

The Influence of Dental Occlusion on Spectrophotometric Tooth Color Determinations

Background: Shade matching is a significant treatment step and a challenge for the clinical team with potentially high costs for color correction. Currently, in the United States, the majority of private dental practitioners use visual color matching, but a recent study has reported a high rate of mistakes of subjective color determination among graduate dentists. Objective: The aim of this retrospective study is to analyze whether a change in the oral background due to dental occlusion can influence tooth color determination. Methods: Volunteer dental students underwent spectrophotometric color assessment using the SpectroShade device. Two measurements were carried out (with the individuals’ occlusion closed and with the occlusion open) on 43 upper central and 58 lateral incisors. Association between colorimetric variables L*, a*, b* and ΔE00 and tooth width, length and tobacco usage were examined. Results: Slight changes in the CIELAB values between closed and open occlusions were found for both the gingival and the central sections as for the overall tooth area, with mean ΔL*=-1.24, Δa*=-1.77, Δb*=-1.42 and ΔE00=1,84. A larger difference was detected in the incisal area, with mean ΔL*=-2.99, Δa*=-1.76, Δb*=-2.83 and ΔE00=3.65. Conclusion: In conclusion, our study showed that dental occlusion does not play a significant role in tooth color matching determinations, even though attention to avoid overbite due to a maximum intercuspation should be made.

Effects of different light sources on tooth shade selection.

Differences in lighting conditions can make matching the shade of a single porcelain tooth to the natural adjacent teeth very challenging. The purpose of the study was to examine visual shade selection under 3 different light sources - natural daylight, a dental operating light and a color-corrected light. The visual assessment was based on a comparison between a shade guide and the target tooth. One observer with normal color vision was asked to visually match the color of the maxillary central right incisor and the maxillary right canine in a group of 100 subjects, aged 22-40 years. Two shade guides were used - VITA Vitapan Classical® and VITA 3D Master® - in natural daylight as well as under an operating light and a handheld light (Demetron Shade Light®). The VITA Easyshade® spectrophotometer was used to evaluate the results of the visual shade selection method. Significant differences were found between the effects of using the shade guide systems (p < 0.05) and light sources (p < 0.05). Overall, the use of the Vitapan Classical shade guide significantly improved the correlation between visual matching and the spectrophotometer readings. Within the limitations of this study, the Vitapan Classical shade guide demonstrated superior agreement in shade selection as compared to the 3D Master shade guide. The Demetron Shade Light was proven to be a useful device for the color matching of artificial teeth in prosthodontic treatment. Visual tooth color matching is a subjective method and it produces the best results under a color-matching light.

THE SIGNIFICANCE OF TRAINING AND EDUCATION IN ACCURATE EVALUATION OF NATURAL TOOTH COLOR

Color is undoubtedly one of the parameters with the highest weight when it comes to assessing the quality of restoration by the patient, especially in the anterior zone of the oral cavity. By precisely matching the restoration color with the remaining teeth, the possibility of inconvenience such as a correction or re-making of the same restoration is minimized. Since determining tooth color in everyday practice is done visually by using specially made color selection shade guides, unawareness of the correct method and the conditions under which it should be administered may increase the failure of the therapy. The aim of our research was to determine whether education and training in determining tooth color influence the choice of precise and correct shade. The study included a total of (N = 90)dental medicine students who were first tested with the Ishihara color vision test and Farnsworth-Munsell 100 HueColor Vision test to exclude the possibility of an error due to the presence of a color vision anomaly of the eye. We have formed two groups with an equal number of respondents, work and control group. Both groups were tested twice with a special color coding program ToothGuideTrainer WEB-final exam, which uses VITA Linearguide 3D-MASTER® shade guide. During the testing, the working group went through education, in the form of lectures, exercises and training tests for determining the color. The control group did not attend the training. The results from both tests were electronically counted. Mean value and standard deviation were determined. Differences between the work and control group were analyzed with t-test. The workgroup showed statistically significant higher points after education and training than the control group. The points earned before training did not differ significantly between the two groups. The education and training for shade matching in dentistry significantly affect the success of selecting the perfect color for future restoration. It is necessary to include more intensive training in determining color within the program of dental medicine studies. The conditions in which the tooth color matching is performed should be strictly controlled.

Dental students' tooth shade selection ability in relation to years of dental education.

Background and Objectives:Perfect tooth shade selection is indispensable for successful esthetic dental restorations. Shade matching is a complex and multidimensional process that involves the cognitive ability of students. Hence, the aim of the present study was to assess and compare the shade matching ability of undergraduate dental students in various years of dental education.Methods:A cross-sectional study was conducted among 150 students enrolled in all five class years of the Bachelor of Dental Surgery course in a dental college in India. Each enrolled participant was presented with two exercises to assess shade matching ability. In the first exercise, basic shade matching ability of the students was assessed by a shade tab matching in a bench setting using Vitapan Classical shade guide. In the second exercise, the participants were asked to perform intraoral tooth color matching to evaluate their ability of shade matching in a clinical setup. Data was analyzed using SPSS version 21 and descriptive statistics were applied. Chi-square test was applied to find out significant differences among years of education.Results:For Exercise 1, 53 participants (35.30%) showed fair color matching ability in bench setting, 26.70% (n = 40) showed good ability, 22.70% (n = 34) demonstrated an excellent ability, whereas 15.30% (n = 23) had a poor ability of color matching. For Exercise 2, where clinical color matching ability of the students was analyzed, 34% (n = 51) obtained fair scores, 33.30% (n = 50) obtained good scores, 26% (n = 39) obtained excellent scores, whereas 6.70% (n = 10) of the participants had poor scores.Conclusion:This study showed that the clinical performance of dental students for shade matching improved as the years of dental education increased. Also, better outcomes were seen in clinical setting as compared to in vitro conditions.

Relationship between tooth value and skin color in patients visiting Royal Medical Services clinics of Jordan.

BackgroundFacial and dental aesthetics are becoming of great concern for patients, especially for the younger generation. Tooth color matching and selection is considered a vital element in order to create an attractive beautiful smile. The importance of tooth color matching is to adjust tooth colors to obtain a good match with adjacent teeth and the skin. This is considered a challenge especially if adjacent teeth were lost or records of patients’ teeth color were not available.ObjectiveThe aim of this study was to determine the relationship between skin complexion and tooth value in a Jordanian population.MethodsA cross-sectional study of 520 individuals who were randomly selected and belonging to different age groups, ranging from 15–65 years, with equal sex distribution. These patients visited the dental clinics at different Jordanian military hospitals. The study was carried out over a period of one year from 2015 to 2016. The randomly selected sample was examined by one researcher. Shade of the middle third of the labial surface of central incisor was determined visually using VITA tooth guide, 3D-MASTER shade guide. Tooth shades were divided into two categories according to their value. The skin complexion was identified using Fitzpatrick skin type test, and was categorized into two categories (fair and dark). Data were statistically analyzed using Epi Info version 6.ResultsA statistically significant tooth shade value difference was discovered among subjects of different skin color (p<0.0001). Individuals with dark skin tend to have lighter teeth, while individuals with light skin tend to have darker teeth. Out of the 304 participants that were with dark complexion 274 (90%) have light teeth, and only 30 (10%) were with dark teeth. Out of the 216 participants with light complexion 172 (80%) have dark teeth and only 44 (20%) have light teeth.ConclusionWithin the limitation of this study, there was an inverse relation between skin complexion and tooth value among a Jordanian population. Thus, considering the skin complexion when choosing tooth shades is helpful in achieving a pleasing good-looking smile, yet further investigations in this field must be carried out.

Reliability of visual and instrumental color matching.

The aim of this investigation was to evaluate intra-rater and inter-rater reliability of visual and instrumental shade matching. Forty individuals with normal color perception participated in this study. The right maxillary central incisor of a teaching model was prepared and restored with 10 feldspathic all-ceramic crowns of different shades. A shade matching session consisted of the observer (rater) visually selecting the best match by using VITA classical A1-D4 (VC) and VITA Toothguide 3D Master (3D) shade guides and the VITA Easyshade Advance intraoral spectrophotometer (ES) to obtain both VC and 3D matches. Three shade matching sessions were held with 4 to 6 weeks between sessions. Intra-rater reliability was assessed based on the percentage of agreement for the three sessions for the same observer, whereas the inter-rater reliability was calculated as mean percentage of agreement between different observers. The Fleiss' Kappa statistical analysis was used to evaluate visual inter-rater reliability. The mean intra-rater reliability for the visual shade selection was 64(11) for VC and 48(10) for 3D. The corresponding ES values were 96(4) for both VC and 3D. The percentages of observers who matched the same shade with VC and 3D were 55(10) and 43(12), respectively, while corresponding ES values were 88(8) for VC and 92(4) for 3D. The results for visual shade matching exhibited a high to moderate level of inconsistency for both intra-rater and inter-rater comparisons. The VITA Easyshade Advance intraoral spectrophotometer exhibited significantly better reliability compared with visual shade selection. This study evaluates the ability of observers to consistently match the same shade visually and with a dental spectrophotometer in different sessions. The intra-rater and inter-rater reliability (agreement of repeated shade matching) of visual and instrumental tooth color matching strongly suggest the use of color matching instruments as a supplementary tool in everyday dental practice to enhance the esthetic outcome.

Influence of Color Education and Training on Shade Matching Skills.

To evaluate the influence of education and training on quality of tooth color matching. Dental students (N = 174), matched the color of eight shade tabs in a viewing booth, using VITA Linearguide 3D-Master shade guide. The experimental group had color education and training between the before and after session. The control group did not have any additional information in between two sessions. Color differences between the task tabs and selected tabs were calculated using CIE formulas. The score for the best match (smallest color difference) was 10 points, the 2nd best match 9 points, down to 1 point for the 10th best match. Means and standard deviations were calculated. Differences were analyzed using the Student t-test. Shade matching scores in the experimental group were significantly better after education and training (p < 0.001), with a mean score before and after shade matching sessions of 7.06 (1.19) and 8.43 (0.92), respectively. The percentage of students in the experimental group that selected one of three best matches increased 24.3%. The control group exhibited no significant improvement in the after session. Within the limitations of the study, education and training improved students' shade matching skills. While the vast majority of dental restorations and practically all restorations in the esthetic zone are tooth colored, the profession as a whole is far from perfect when it comes to accurate shade matching. Education and training can improve shade matching ability: enhanced esthetics of dental restorations, increased patient satisfaction, and a reduced number of color corrections are some of the notable benefits and rewards. (J Esthet Restor Dent 00:000-000, 2016) J Esthet Restor Dent 28:287-294, 2016).

Color Selection and Reproduction in Dentistry. Part 1: Fundamentals of Color

Knowing the optical phenomena that determine the chromatic expression of tooth tissues and their clinical application are essential factors for obtaining esthetic excellence in restorative treatments. Tooth color matching with restorative materials is influenced by several factors, which can produce frustrating results, for both the professional and the patient, when they are not controlled. Based on scientific evidence, a sequence of three articles were performed describing the fundamentals of color formation, the characteristics of the light interaction with the dental tissues and restorative materials and the main methods of color selection and reproduction in esthetic dentistry.

Comparison of Time Consumption and Color Matching Results of Different Dental Occupational Groups

A study was conducted to compare the accuracy and time consumption of shade matching tasks performed by students, clinicians, and dental technicians. A total of 126 participants were asked to pair shade tabs and to choose the best shade match for three natural teeth using the Chromascop shade guide. Time consumption was recorded. The frequency of correct answers and time consumption results were compared across occupational groups and by levels of clinical experience. No significant difference was found between occupational groups in shade tab pairing or natural tooth color matching. Experience did not affect the shade tab pairing, but experienced participants were better in natural tooth color matching. Clinicians performed the shade tab matching task faster than preclinical and clinical students, while technicians were faster than preclinical students. In the natural tooth color matching task, clinicians and technicians were faster than students. Regarding experience, novice observers were slower than experienced individuals. A significant negative correlation was observed between time consumption for visual shade matching and the frequency of correct matches for both shade tabs and natural teeth. The level of professional experience improved color matching of natural teeth. Overall, clinicians and dental technicians performed faster than students, while lower time consumption for shade matching was associated with better scores.

Evaluating the accuracy of tooth color measurement by combining the Munsell color system and dental colorimeter

As we pay increasing attention to dental aesthetics, tooth color matching has become an important part of daily dental practice. This aim of this study was to develop a method to enhance the accuracy of a tooth color matching machine. The Munsell color tabs in the range of natural human teeth were measured using a tooth color measuring machine (ShadeEye NCC). The machine's accuracy was analyzed using an analysis of variance test and a Tukey post-hoc test. When matching the Munsell color tabs with the ShadeEye NCC colorimeter, settings of Chroma greater than 6 and Value less than 4 showed unacceptable clinical results. When the CIELAB mode was used, the a* value (which represents the red–green axis in the Commission Internationale de l'Eclairage color space) made no significant difference (p=0.84), the L* value (which represents the lightness) resulted in a negative correlation, and the b* value (which represents the yellow–blue axis) resulted in a positive correlation with ΔE. When the Munsell color tabs and the Vitapan were measured in the same mode and compared, the inaccuracies showed that the Vitapan was not a proper tool for evaluating the stability and accuracy of ShadeEye NCC. By knowing the limitations of the machine, we evaluated the data using the Munsell color tabs; shade beyond the acceptable range should be reevaluated using a visual shade matching method, or if measured by another machine, this shade range should be covered to obtain more accurate results.

Evaluating Tooth Color Matching Ability of Dental Students

Visual shade matching has remained a skill acquired through clinical experience. The purpose of this study was to evaluate the shade matching ability of dental students as they progress through their education. Sixty-five students, representing four levels of experience by year enrolled in dental school, participated in this study. Students were given a preclinical shade tab matching task. They were also asked to choose the best shade match for a natural tooth in each of three patients. The natural tooth shade matching task was designed to have simple, moderate, and complex cases to match. The frequency of correct answers was compared across samples across the four levels of fundamental tab match ability and clinical experience. On average, 51 percent of the students were able to match the correct shade tab in the matching task in a bench setting. For the natural tooth color matching task, 49.2 percent of the students selected the clinically acceptable color matched shade tabs (ΔE*≤2.69). Although there was no statistically significant difference across the levels of fundamental ability and experience, rates of correct answers for natural tooth color matching progressively improved for the complex case from year 1 to year 4. This study reveals that, for complex cases, education and knowledge of color science combined with clinical experience improve students' ability for color matching in a clinical setting.

Spectrophotometric Analysis of Tooth Color Reproduction on Anterior All‐Ceramic Crowns: Part 2: Color Reproduction and Its Transfer from In Vitro to In Vivo

Color reproduction of an anterior tooth requires advanced laboratory techniques, talent, and artistic skills. Color matching in a laboratory requires the successful transfer from in vivo with careful considerations. The purpose of this study was to monitor and verify the color reproduction process for an anterior all-ceramic crown in a laboratory through spectrophotometric measurements. Furthermore, a crown insertion process using composite luting cements was assessed, and the final color match was measured and confirmed. An all-ceramic crown with a zirconia ceramic coping for the maxillary right central incisor was fabricated. There was a significant color difference between the prepared tooth and the die material. The die material selected was the closest match available. The ceramic coping filled with die material indicated a large color difference from the target tooth in both lightness and chromaticity. During the first bake, three different approaches were intentionally used corresponding with three different tooth regions (cervical, body, and incisal). The first bake created the fundamental color of the crown that allowed some color shifts in the enamel layer, which was added later. The color of the completed crown demonstrated an excellent color match, with Delta E 1.27 in the incisal and 1.71 in the body. In the cervical area, color match with Delta E 2.37 was fabricated with the expectation of a color effect from the underlying prepared tooth. The optimal use of composite luting cement adjusted the effect from the underlying prepared tooth color, and the color match fabricated at a laboratory was successfully transferred to the clinical setting. The precise color measurement system leads to an accurate verification of color reproduction and its transfer. CLINICAL SIGNIFICANCE The use of a dedicated dental spectrophotometer during the fabrication of an all-ceramic crown allows the dentist and the laboratory technician to accurately communicate important information to one another about the shade of the tooth preparation, the shade of the contralateral target tooth, and the influence of luting cement on the final restoration, thereby allowing the technician better control over the outcome of their tooth color matching efforts and the final color match of an all-ceramic restoration.

Toothguide Trainer tests with color vision deficiency simulation monitor

Objectives The aim of this study was to evaluate whether simulated severe red and green color vision deficiency (CVD) influenced color matching results and to investigate whether training with Toothguide Trainer (TT) computer program enabled better color matching results. Methods A total of 31 color normal dental students participated in the study. Every participant had to pass the Ishihara Test. Participants with a red/green color vision deficiency were excluded. A lecture on tooth color matching was given, and individual training with TT was performed. To measure the individual tooth color matching results in normal and color deficient display modes, the TT final exam was displayed on a calibrated monitor that served as a hardware-based method of simulating protanopy and deuteranopy. Data from the TT final exams were collected in normal and in severe red and green CVD-simulating monitor display modes. Color difference values for each participant in each display mode were computed ( ∑ Δ E a b * ), and the respective means and standard deviations were calculated. The Student's t-test was used in statistical evaluation. Results Participants made larger Δ E a b * errors in severe color vision deficient display modes than in the normal monitor mode. TT tests showed significant ( p < 0.05) difference in the tooth color matching results of severe green color vision deficiency simulation mode compared to normal vision mode. Students’ shade matching results were significantly better after training ( p = 0.009). Conclusions Computer-simulated severe color vision deficiency mode resulted in significantly worse color matching quality compared to normal color vision mode. Toothguide Trainer computer program improved color matching results.

Prevalence of color vision-deficient individuals among dental students

O objetivo deste estudo foi identificar indivíduos deficientes para visão de cores, testando a acuidade visual dentre um grupo de estudantes de Odontologia, e comparar o resultado obtido com os resultados encontrados na literatura, considerando o prejuízo das discromatopsias congênitas para a Odontologia, especialmente na escolha da cor dental. Foram escolhidas seis cartas determinadas dentre as cartas da seqüência do Teste de Ishihara e essas foram apresentadas como seis “slides” para 308 indivíduos, alunos de Odontologia. Durante a apresentação, o indivíduo preenchia um formulário com suas informações pessoais e a leitura da carta que estava vendo. O Teste de Ishihara é um teste de leitura de placas pseudo-isocromáticas usado para identificar indivíduos com discromatopsias congênitas; e é o mais usado dos testes para esse fim. Trezentos e oito indivíduos foram avaliados. Desses, 121 (39,3%) eram homens e 187 (60,7%) eram mulheres, com idades entre 19 e 37 anos. Do total, 13 (4,2%) foram considerados indivíduos cor-deficientes: 8 (6,6%) homens e 5 (2,6%) mulheres. Após a análise estatística, pudemos afirmar que, com 95% de probabilidade, a proporção real de homens cor-deficientes está no intervalo de 3,14% a 12,16%; e a proporção real de mulheres cor-deficientes está no intervalo de 0,96% a 5,68%. Rejeitamos a hipótese de que a população feminina deste estudo está de acordo com a encontrada na literatura. Por outro lado, a população masculina deste estudo parece estar de acordo com os achados da literatura.