• Journal of Technologic Dentistry
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• v.32 no.4
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• pp.327-335
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• 2010

Purpose: The purpose of this study was to investigate the correlation between zirconia core thickness and color tone blocking of discolored tooth and metal post. Methods: For this study, we made 20-porcelain sample and 4-metal sample( liechtenstein IPS e.max) bonded to zirconia core of different thickness with cement(Relyx ARC-3M USA)for produce discolored. We measured the color-spectral characteristics, using Shadepilot equipment(Degudent USA).We measured it with Shadepilot equipment set by automated average mode in 3 times And applied the average value obtained from 2 times of measurement in the middle of each sample. Results: As a result of analysing color-spectral characteristics on zirconia core sample, Depending on the thickness of zirconia core, the value of brightness(${\Delta}L*$:color-spectral characteristic) was increased within limited range, value of ${\Delta}a*$, ${\Delta}b*$ was decrease. Conclusion: Consequently, we obtained the following results: Changes of sample color were observed depending on the thickness of zirconia, but the range of change did not exceed the scope range of shade guide. The case of metal posts, shade guide color D2 were observed in 0.5mm of zirconia core thickness. As a result, in case of porcelain, increasing the zirconia thickness of 0.3mm or more is unnecessary for color blocking effect, in case of metal post, considering the discolored tooth, thickness of zirconia with at least 0.5mm or more is recommended.

• Restorative Dentistry and Endodontics
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• v.44 no.1
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• pp.6.1-6.11
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• 2019

Objectives: The aim of the present study was to evaluate the effect of whitening mouth rinses alone and in combination with conventional whitening treatments on color, microhardness, and surface roughness changes in enamel specimens. Materials and Methods: A total of 108 enamel specimens were collected from human third molars and divided into 9 groups (n = 12): 38% hydrogen peroxide (HP), 10% carbamide peroxide (CP), 38% HP + Listerine Whitening (LW), 10% CP + LW, 38% HP + Colgate Plax Whitening (CPW), 10% CP + CPW, LW, CPW, and the control group (CG). The initial color of the specimens was measured, followed by microhardness and roughness tests. Next, the samples were bleached, and their color, microhardness, and roughness were assessed. Data were analyzed through 2-way analysis of variance (ANOVA; microhardness and roughness) and 1-way ANOVA (color change), followed by the Tukey post hoc test. The Dunnett test was used to compare the roughness and microhardness data of the CG to those of the treated groups. Results: Statistically significant color change was observed in all groups compared to the CG. All groups, except the LW group, showed statistically significant decreases in microhardness. Roughness showed a statistically significant increase after the treatments, except for the 38% HP group. Conclusions: Whitening mouth rinses led to a whitening effect when they were used after conventional treatments; however, this process caused major changes on the surface of the enamel specimens.

• Restorative Dentistry and Endodontics
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• v.44 no.1
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• pp.10.1-10.11
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• 2019

Objectives: The objective of this study was to assess coronal discoloration induced by the following intracanal medicaments: calcium hydroxide (CH), a mixture of CH paste and chlorhexidine gel (CH/CHX), and triple antibiotic paste (3Mix). Materials and Methods: Seventy extracted single-canal teeth were selected. Access cavities were prepared and each canal was instrumented with a rotary ProTaper system. The specimens were randomly assigned to CH, CH/CHX, and 3Mix paste experimental groups (n = 20 each) or a control group (n = 10). Each experimental group was randomly divided into 2 subgroups (A and B). In subgroup A, medicaments were only applied to the root canals, while in subgroup B, the root canals were completely filled with medicaments and a cotton pellet dipped in medicament was also placed in the pulp chamber. Spectrophotometric readings were obtained from the mid-buccal surface of the tooth crowns immediately after placing the medicaments (T1) and at 1 week (T2), 1 month (T3), and 3 months (T4) after filling. The ${\Delta}E$ was then calculated. Data were analyzed using 2-way analysis of variance (ANOVA), 3-way ANOVA, and the $Scheff{\acute{e}}$ post hoc test. Results: The greatest color change (${\Delta}E$) was observed at 3 months (p < 0.0001) and in 3Mix subgroup B (p = 0.0057). No significant color change occurred in the CH (p = 0.7865) or CH/CHX (p = 0.1367) groups over time, but the 3Mix group showed a significant ${\Delta}E$ (p = 0.0164). Conclusion: Intracanal medicaments may induce tooth discoloration. Use of 3Mix must be short and it must be carefully applied only to the root canals; the access cavity should be thoroughly cleaned afterwards.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.3
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• pp.280-290
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• 2021

Color stability of pulp-capping material is considered vital to the final aesthetic result since the material is placed in the coronal area. The purpose of this study was to compare the color stability of various pulp-capping materials by analyzing color change of tooth over time. A cavity was formed in the crown of the extracted premolar, and 4 types of pulp-capping materials were filled. Color assessment was performed with a spectrophotometer at different intervals: before placement; immediately after material placement; 1 day, 1 week, 2 weeks, 4 weeks, 8 weeks, 12 weeks, and 16 weeks after placement. Proroot white MTA^® and TheraCal LC^® showed a significant decrease in the L^* value and an increase in the ∆E^* value over time. In contrast, Biodentine^® and Well-Root^TM PT showed no significant change in the L^* value and maintained a steady ∆E^* value. The application of pulp-capping materials containing bismuth oxide as a radiopacifier may result in a color change of teeth. Long-term color stability of pulp-capping materials should be considered when treating teeth with thin enamel thickness or in aesthetically important area.

• Journal of dental hygiene science
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• v.13 no.2
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• pp.191-196
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• 2013

The purpose of this study was to evaluate the tooth brightening of whitening dentifrice and to determine the tooth stain level over 20 days depending on beverages that have various pH values after using whitening dentifrice. Thirty teeth were randomly divided into two groups. Group 1 was provided with a whitening dentifrice for 3 minutes and group 2 was treated with a control dentifrice for 3 minutes thrice a day for four weeks. All teeth were photographed using a digital imaging system under a stereomicroscope (magnification, ${\times}10$). After four weeks, the ten teeth were immersed in the tea solution, another of ten teeth were immersed in the orange juice and the other of the teeth were immersed in the coffee solution. Three solutions were renewed each day for the appropriate groups. Stain development was monitored under a stereomicroscope daily over 20 days period by immersion of teeth in a tea, juice, coffee solution at room temperature ($25^{\circ}C$) in individual container. Whitening dentifrice gave a statistically higher value of overall color change as compared to control dentifrice after 21 days (p<0.05). Stain level of whiten tooth immersed in orange juice was the grestest overall color change, but there was not statistically significant difference (p>0.05). On the other hand, stain level of whiten tooth immersed in coffee and green tea showed a statistically significant difference after 15 days and 5 days, respectively (p<0.05). Tooth immersed in green tea was higher negative value than control dentifrice. The tooth using whitening dentifrice was shown to be effectively whiter color than control dentifrice. However, stain level by orange juice, coffee and green tea has a strong staining effect.

• Journal of dental hygiene science
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• v.22 no.1
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• pp.57-66
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• 2022

Background: This study aimed to investigate the effect of selecting commercially available blending teas and applying them to bovine teeth on color change over time. Methods: After selecting healthy bovine teeth, using a cutting-disc, 105 specimens with a dimension of 5×5×3 mm were prepared, and 15 specimens were distributed to each group. Black tea was used as a positive control, water was used as a negative control, and blended tea of five types was used as an experimental group. First, pH and buffering capacity were measured with a pH meter, and tooth color was determined using a spectrophotometer before immersion in the blending tea solution and 1, 5, 7, 14, and 21 days after immersion. Thereafter, the shape change of the enamel surface was observed using a scanning electron microscope, and SPSS ver.26 was used to analyze the color change. Results: The average pH of the five blending teas in the experimental group was 3.78, and the pH of group 3 (strawberry rhubarb) was the lowest at 3.22. The pH levels of black tea and water were 5.19 and 7.30, respectively. The buffering capacity was the highest in group 3 at both pH levels of 5.5 and 7.0. The L^*a^*b^* color change according to immersion time was the largest in group 4 (rooibos yellow flower), and the amount of color change was large in black tea and group 4. As a result of observing the enamel surface of bovine teeth, changes in the surface shape were noted in all groups immersed in the experimental solution for 21 days, except for water. Conclusion: There was a significant difference between the experimental groups in terms of color change according to the immersion time, and color and enamel surface changes were observed in black tea and all experimental groups, except for water.

• Journal of Korean society of Dental Hygiene
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• v.18 no.1
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• pp.19-29
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• 2018

Objectives: Despite a rise of an interest in tooth whitening, diverse problems are being caused in case of hydrogen peroxide that is being used as a tooth bleaching agent. Thus, the aim was to examine tooth whitening effectiveness using natural products as a plan for supplementing this. Methods: As a result of having measured a tooth color through using VITA Easyshade V after having developed toothpaste with the application of extracts such as Citrus Peels, Mulberry (Morus alba L.) Root Bark, strawberry, and lemon, and then having used it for 10 weeks, they are as follows. Both upper and lower 6 anteriors mostly got brighter. Results: A statistically significant difference was shown especially in the right canine (p=0.015), in the right central incisor (p=0.007), and in the left central incisor (p<0.001). In consequence of having measured a color change, the tooth got brighter gradually in the higher extract content and in the lengthier use time. In case of canine, it got less bright compared to other teeth. In the outcome of evaluating sensuality, most of the questions were indicated to be high in case of using a whitening toothpaste for 10 weeks. But in what "there is no stickiness in the mouth, the stickiness was more felt in the use up to 5 weeks, but was improved in 10 weeks. Conclusions: The bleaching effectiveness was proved by developing a toothpaste with the application of natural extracts. A short-term effect cannot be seen like a whitening agent of using hydrogen peroxide. But there is a continuous effect in consideration of tooth-brushing more than 3 times a day.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.123-125
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• 2008

Enamel layer consists of carbonated hydroxyapatite of 85%, water of 12% and protein of 3% and lipid and tentin consists of carbonated hydroxyapatite of 47%, water of 20% and protein of 33% and lipid so if heat is increased in teeth and then teeth color is discolor. In case high temperature is applied in teeth, teeth color changed quality is measured about change of time for minimize teeth change of color. Spectroscopic light intensity special quality by change of time rise at specification temperature.

• Restorative Dentistry and Endodontics
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• v.25 no.4
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• pp.599-605
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• 2000

Among the effects of tooth bleaching on composite resins, degree of color change and dye deposition onto composite resins after office bleaching were investigated in vitro. Seventy two disc-shaped resin samples were fabricated with hybrid type composite resin, Z-100 under 3 different environments(24 samples for each environment) characterized by 3 kinds of light-curing intensity and duration($250mW/cm^2$-20sec., $250mW/cm^2$-40sec., $550mW/cm^2$-20sec.). As control, one-third samples of each group were not treated with bleaching agent. The remaining two-thirds samples of each group were treated with bleaching agent(bleaching group). Then, before thermocycling procedure in coffee bath, the half of the samples treated with bleaching agent were polished(polishing group) with polishing system. SofLex, but the other half(not-polishing group) and control group were not polished. Another 72 samples were also made with microfilled type composite resin. Sillux Plus and treated according to the experimental procedures mentioned above. The color of each resin sample was measured before bleaching, after bleaching, and after thermocycling preceded by bleaching. And color difference was evaluated. It was concluded as follows: 1. The amount of color change of resin samples after office bleaching was not statistically significant(p>0.05). But the samples which were treated with bleaching agent showed more color change than that of control group. 2. After thermocycling in coffee bath, the amount of color change of resin samples between control and bleaching group was not statistically significant(p>0.05). 3. After thermocycling in coffee bath, the polishing procedure of resin samples showed no statistically significant difference(p>0.05) between polishing and not-polishing group in the aspect of color change.

• Journal of Dental Rehabilitation and Applied Science
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• v.19 no.2
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• pp.69-74
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• 2003

The purpose of this study was to obtain the color change information for natural tooth of all age groups. Fifty Korean subjects(25 men and 25 women) were randomly selected for this study. They were ranged in age from 24 to 67 years old and were classified into 5 age groups for each sex: 20 to 29, 30 to 39, 40 to 49, 50 to 59, 60 to 69 years. Maxillary central incisor of each subject free from obvious discoloration and restorations on the sites to be measured was selected. Three sites on the labial surface, incisal, middle, cervical area were measured and a circular area of 1.0mm in diameter was measured at each site by the spectrophotometer. The obtained results of this study were as follows: 1) Natural tooth color showed a significant decrease in linghtness($L^*$) at the cervical site(P<0.05). 2) Red/green chromaticity($a^*$) showed a significant increase at all sites(P<0.01). But it was not enough to have a statistic significance among three sites by aging. 3) Yellow/blue chromaticity($b^*$) showed an increase at all sites(P<0.05). But it didn't change significantly among three sites by aging.