• Restorative Dentistry and Endodontics
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• v.18 no.1
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• pp.215-226
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• 1993

Color stability of tooth colored restorative resins is an important factor, particularly in anterior teeth restoration. The purpose of this study was to evaluate the color stability and opacity change of several light curing composite resins. Specimens of eight composite resins(Prisma AP. H., Brilliant Enamel, Charisma, Durafil, Helio Progress, Herculite XR, P-50 and Silux Plus) were divided into two groups : In Group 1, the specimens were polymerized by visible light curing unit for 60 seconds on both sides and in Group 2, the post-cured specimens were heat tempered by light/heat curing unit for 45 units(about 18 min.). All specimens were stored in distilled water at $60^{\circ}C$ for 30 days. The color characteristics($L^*,a^*,b^*$) and opacity of the specimens before and after immersion were measured by spectrocolorimetry and the total color difference(${\Delta}E^*$) and opacity change (${\Delta}Y%$) were computed. The results obtained were as follows : 1. SP and APH in both groups, DF, HP and HXR in Group 1 showed ${\Delta}E^*$-value above 2.0. 2. DF, HP, SP and HXR in Group 1 showed higher ${\Delta}E^*$-value than in Group 2, but the others had no significant difference. 3. The opacity of CH and HXR in Group 1, and of CH and BE in Group 2 decreased after immersion, while that of the others increased. 4. Opacity change of BE, P50 and HXR was significantly different between Group 1 and 2. These results suggest that color change in the post-cure heat tempered specimens by light/heat curing unit was smaller than that of the specimens polymerized by visible light curing unit. No clinically detectable opacity changes were noted for any materials in either goup.

• Journal of dental hygiene science
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• v.23 no.1
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• pp.20-28
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• 2023

Background: This study aimed to determine the effect of ramen sauce on tooth tone changes over time, after selecting three different ramen colors from the ramens sold in the market, and applying the sauce to bovine teeth. Methods: Healthy bovine teeth were selected, and cutting discs were used to produce 60 specimens (5× 5× 3 mm), with 15 specimens distributed per county. Three types of ramen (buldak, chacharoni black bean sauce, and ottogi curry noodle) were used as the experimental group, and water was used as the negative control group. Tooth tone measurement was performed using a spectrophotometer (CM-700d) to measure the color before and after 1 (3 h 44 min), 2 (7 h 28 min), 3 (11 h 12 min), and 4 weeks (14 h 56 min). Analysis of the color tone change was performed using Statistical Package for the Social Sciences version 28. Results: In the experimental group, there was a significant color tone change before and after immersion. L^* indicated the largest change in black bean sauce ramen, a^* indicated buldak ramen, and b^* indicated the largest change in curry ramen. The amount of color change (∆E^*) was the largest in curry ramen, followed by buldak and black bean sauce ramens. The results of the post-hoc analysis showed significant differences between all groups except buldak and black bean sauce ramens. Conclusion: All three types of ramen revealed significant color change before and after immersion, and curry ramen showed the largest amount of color change among them.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.1
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• pp.1-6
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• 2000

Dentinogenesis imperfecta is an inherited disorder of dentin formation, usually exhibiting an autosomal dominant mode of transmission. Type I dentinogenesis imperfecta occurs in patients afflicted with osteogenesis imperfecta. Type II dentinogenesis imperfecta is not associated with osteogenesis imperfecta. Type III dentinogenesis imperfecta (Brandywine type) occurs in a racial isolate area in the state of Maryland. In all three types, teeth of both dentitions are affected with variable clinical appearances. The teeth are opalescent with the color ranging from bluish-gray to brown to yellowish. The dentin is abnormally soft, providing inadequate functional support to the overlying enamel. Although the enamel is normal, it fractures or chips away easily, exposing the occlusal and incisal dentin. The exposed soft dentin often undergoes rapid and severe functional attrition. The teeth exhibit bulb-shaped crowns with constricted cementoenamel junctions and thin roots. The teeth will exhibit varying stages of obliteration of the coronal and root pulpal chambers. The cementum, periodontal ligament and supporting alveolar bone appear normal. The enamel is normal. The mantle dentin remains nearly normal, whereas the remaining dentin is severely dysplastic. The dentinal tubules are disoriented, irregular, widely spaced, and usually larger than normal.

• Journal of dental hygiene science
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• v.8 no.4
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• pp.255-260
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• 2008

The purposes of this study were to examine the effect of 35% hydrogen peroxide (HP) bleaching agent on the changes in physical and chemical characteristics of tooth. The bleached teeth showed an apparent color changes. The whiteness increased linearly within the tested period as the period of bleaching increased. The microhardness between bleached groups after bleaching showed any statistically significant difference according to the paried t-test. The bleached enamel surface showed any apparent morphological changes compared to the enamel which was stored in distilled water only. The difference of the total mineral contents for the distilled water and hydrogen peroxide did not show statistical significance. These results demonstrated that bleaching using 35% hydrogen peroxide were adversely affects application time of experimental group and may confirm the safety of using these agents for a short time in dentist-monitored bleaching.

• Journal of the Korea Convergence Society
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• v.6 no.5
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• pp.165-171
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• 2015

This in vitro study compared the effect of bleaching agent modified by the addition of $TiO_2$ catalyst converged bleaching agent. Nonvital teeth samples were assigned to four group(n=6) according to the bleaching agent: 10% carbamide peroxide(CP) bleaching agen, 10% CP with 10% $TiO_2$ catalyst, 20% CP bleaching agent and 20% CP with 20% $TiO_2$ catalyst. Changes in enamel color were evaluated on minutes 30, 60, 180, 300 and 420. It was found that 20% CP with 20% $TiO_2$ catalysis increased the whiteness and overall color value and showed significantly brightened. The teeth bleaching time was reduced with $TiO_2$ catalyst converged bleaching agent. This result will contribute to development of the teeth bleaching agent.

• Restorative Dentistry and Endodontics
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• v.34 no.4
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• pp.309-323
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• 2009

In this study we evaluated the influence of both the thickness of residual enamel and the color of the composite resins applied to lingual surface on the labial surface color. Background plates were made by randomly (A1, A2, A6D, B1, B2, B3, C1, C2, C6D) selected colors of Filtek Supreme (3M ESPE, St. Paul, U.S.A.) composite resin. Crown portion of 9 maxillary central incisors were cut off and embedded with acrylic resin except labial surface. Samples of average thickness of 2.2 mm were obtained after cutting it in a thickness of 2.5 mm from the labial surface and sandpaper polish. The shade of composite resin background was measured using Spectrophotometer ($Spectrolino^{(R)}$, GretagMacbeth, Regensdorf, Switzerland). And CIE $L^{\ast}a^{\ast}b^{\ast}$value of 2.2 mm thickness tooth samples were measured on the 9 composite resin backgrounds. And then, the cutting side of tooth samples was ground to the extent of 1.9 mm, 1.6 mm, 1.3 mm, 1.0 mm and placed on composite resin backgrounds and measured $L^{\ast}a^{\ast}b^{\ast}$values with the same method. In all samples, $L^{\ast}$value and $b^{\ast}$value seemed to have a tendency of decreasing as thickness of tooth sample becomes thinner regardless of background colors (p < 0.05). But, $a^{\ast}$value didn't show the significant differences depending on the thickness.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.22 no.2
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• pp.273-282
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• 1992

The purpose of this study was to propose the utility which was evaluated the digital image processing and clinical application of the videodensitomery. The experiments were performed with IBM-PC/16bit-AT compatible, video camera(CCdtr55, Sony Co., Japan), an color monitor(MultiSync 3D, NEC, Japan) providing the resolution of 512×480 and 64 levels of gray. Sylvia Image Capture Board for the ADC(analog to digital converter) was used, composed of digitized image from digital signal and the radiographic density was measured by 256 level of gray. The periapical radiograph(Ektaspeed EP-21, Kodak Co., U. S. A) which was radiographed dried human mandible by exposure condition of 70 kVp and 48 impulses, was used for primary X-ray detector. And them evaluated for digitzed image by low and high pass filtering, correlations between aluminum equivalent values and the thickness of aluminum step wedge, aluminum equivalent values of sound enamel, dentin, and alveolar bone, the range of diffuse density for gray level ranging from 0 to 255. The obtained results were as follows: 1. The edge between aluminum steps of digitized image were somewhat blurred by low pass filtering, but edge enhancement could be resulted by high pass filtering. Expecially, edge enhancement between distal root of lower left 2nd molar and alveolar lamina dura was observed. 2. The correlation between aluminum equivalent values and the thickness of aluminum step wedge was intimated, yielding the coefficient of correlation r=0.9997(p<0.00l), the regression line was described by Y=0.9699X+0.456, and coefficient of variation amounting to 1.5%. 3. The aluminum equivalent values of sound enamel, dentin, and alvolar bone were 15.41㎜, 12.48㎜, 10.35㎜, respectively. 4. The range of diffuse density for gray level ranging from 0 to 255 was wider enough than that of photodenstiometer to be within the range of 1-4.9.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.4
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• pp.704-709
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• 1998

Amelogenesis imperfecta represents a group of hereditary conditions that manifest enamel defects without evidence of generalized or systemic disorders. These enamel disorders are apparently heterogeneous in the basic chemical structure, resulting in a diverse presentation of clinical characteristics. The reported prevalence of amelogenesis imperfecta varies from 1 in 14,000-16,000 to 1.4 in 1,000 depending on specific population studied with the autosomal dominant hypocalcification type of amelogenesis imperfecta believed to be the least prevalent. The most widely accepted current classification system for delineating the amelogenesis imperfecta types considers the mode of inheritance and clinical manifestations. Three major groups are recognized; hypoplastic, hypocalcified, and hypomaturation types. Delineating specific types of amelogenesis imperfecta can be confusing due to the phenotypical similarity of many forms and that the most recent classification lists 14 different types. A 12 year-old female patient came to our pediatric dentistry clinic complaining of the ugly shape and color of her teeth, especially the upper front area. Although the goal of the treatment was mainly focused on the improvement of patient's esthetics, longevity of the restorations was also considered in selecting the appropriate restorative system, resin jacket crown, which can satisfy the both aspects.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.3
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• pp.400-405
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• 2004

Biliary atresia is defined as a complete obstruction of bile flow owing to destruction or absence of all or part of the extrahepatic bile ducts. This disease is occurring in approximately 1:10,000 live births and moderate predominance of female is noted. The etiology of biliary atresia remained unsolved. The signs and symptoms are hyperbilirubinemla, jaundice, clay-colored stools, steatorrhea, dark yellow urine and hepatomegaly. Currently biliary atresia is best managed by hepatic portoenterostomy with or without liver transplantation. Biliary atresia patients with these cases showed staining of the teeth. The stains ranged in color from yellowish-brown to deep green. Enamel hypoplasia was all erupted teeth present. Patients had poor oral hygiene and rampant caries.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.1
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• pp.1-10
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• 2017

The present study aimed to evaluate the validity of resin infiltration in improving color stability after tooth whitening. Enamel samples were extracted from 40 healthy bovine upper incisors, and primary staining and whitening were performed. After that, specimens were randomly divided into 3 groups : resin infiltration group (n = 15, RI group), resin adhesive group (n = 15, RA group), and control group (n = 10). Secondary staining was performed on all samples. Coloration was assessed 5 times as follows: initial color, immediately after staining, after whitening, after resin application, and after secondary staining. Color was measured using a spectrophotometer and recorded by using the CIE $L^*a^*b^*$ color space. The color changes after primary staining for the RI, RA, and control groups were $12.16{\pm}3.50$, $12.16{\pm}3.38$, and $15.81{\pm}6.39$, whereas those after secondary staining were $15.21{\pm}7.19$, $15.93{\pm}4.31$, and $26.62{\pm}17.89$. Color changes after secondary staining showed a significant difference between the RI and control groups. In the within-group comparison between primary and secondary staining, there was no significant difference found in the RI group only (p = 0.26). The results suggest that Color stability after tooth whitening can be improved using resin infiltration.