• Restorative Dentistry and Endodontics
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• v.49 no.3
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• pp.23.1-23.10
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• 2024

Objectives: Previous in vitro studies determined the whitening effects of bleaching products on stained resin composite surfaces. This in vitro study aimed to verify the effectiveness of a whitening system on composite resin previously subjected to pigmentation, specifically examining the depth of whitening effectiveness within the material structure. Materials and Methods: A commercially available nano-filled composite resin was used. Specimens were stained using a coffee-based solution and a 10% carbamide peroxide-based gel was employed as the whitening agent. The pigment's penetration and the effect of the bleaching gel were evaluated by measuring color (CieLab values) from the outer edge to the inner part of the specimens. Color measurements were taken at 14 points, starting from 0.1 mm from the external perimeter up to 3.0 mm. Results: Analysis of variance tests showed a statistically significant difference between the Control Group (CG), Pigmentation Group, and Whitening Group. The whitening agent was effective up to 1.5 mm in depth, with Whiteness index (W) values not statistically different from those of CG up to 0.5 mm in depth. Conclusions: Whitening agents on nano-filled resin composite previously pigmented appear effective in restoring the W to values similar to the original, particularly in the superficial layers of the sample.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.7 no.1
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• pp.64-70
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• 1998

Recently as the interest on Esthetic Dental Prosthesis is arising, the domains of Esthetic Dentistry is being widely investigated. Esthetic Dental Prosthesis is influenced greatly by the shape, color, tooth arrangement of the teeth and the facial features(including the lips). So the degree to which these characters harmonize will be the professional esthetical standard while the satisfaction of the patient will be another esthetical measure. The reason for this is that each and every one of us has a different standard of what is considered beautiful. Of course it doesn't mean that every standard is correct. Then what does Esthetical Prosthesis mean and what should the standard be? This must be defined as a prosthesis that satisfies the basic requirements - margin, contour, occlusion, and at the same time it should restore the shape, color, and tooth arrangement which the client(patient) would love to have. As Esthetic Prosthesis contains its subjective meaning a great deal, it shouldn't be simply distinguished between the beauty of the teeth itself or ugliness. Also in some case, it needs surgical treatment to make it harmonious in the whole aspect so that one may keep the feeling of satisfaction and security. Then what is the shape, color, tooth arrangement that each individual wants? There is an indefinite variety. For example, considering arrangement both regular and irregular is considered beautiful by each different individual. Regular arrangement may be the standard of beauty for some, while irregular arrangement may be thought of as natural looking and beautiful. That is why there must be enough communication with the patient and an agreement be made at the clinic before a diagnostic plan and actual surgery. The treatment plan as mentioned above must be sent to the dental laboratory. In this research, by using case studies, I am going to the importance and appropriateness of the data and information for the dental technician's esthetic prosthesis.

• 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.

• The Journal of Advanced Prosthodontics
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• v.11 no.5
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• pp.286-296
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• 2019

PURPOSE. The aim was to study the masking ability of high-translucency monolithic zirconia and provide guidance in selecting resin luting cements in order to mask discolored substrates. MATERIALS AND METHODS. 160 high-translucency zirconia specimens were divided into 32 groups depending on their thickness and shades. Using five shades of try-in paste, the specimens were luted onto the substrates (Co-Cr, precious-metal, opaque porcelain-sintered Co-Cr, opaque porcelain-sintered precious-metal, and 5M3-shade zirconia). All CIELAB color parameters were measured and statistically analyzed. RESULTS. Zirconia shade and thickness and try-in paste shade affected CIELAB color parameters (P=.000) in different substrates groups, and there were interactions among these factors (P=.000). All five try-in paste shades can be chosen to achieve ${\Delta}E$ values of zirconia with 1.2 - 1.5 mm for masking dark-tooth-like 5M3-shade and zirconia with 1.5 mm for masking precious-metal groups < 2.6. Only suitable try-in paste shades were used, can ${\Delta}E$ values that less than 2.6 be achieved when applied translucent monolithic zirconia with 0.7-1.0 mm for masking dark-tooth-like 5M3-shade and zirconia with 0.7 - 1.2 mm for masking precious-metal groups. CONCLUSION. Choosing suitable resin cement shades is necessary for high-translucency monolithic zirconia to achieve ideal masking ability (${\Delta}E$ < 2.6) on the dark-tooth.

• Restorative Dentistry and Endodontics
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• v.46 no.4
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• pp.52.1-52.11
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• 2021

Objectives: This study evaluated the effects of low and moderate concentrations of triple antibiotic paste (TAP) and double antibiotic paste (DAP) loaded into a hydrogel system on crown discoloration and explored whether application of an adhesive bonding agent prevented crown discoloration. Materials and Methods: Intact human molars (n = 160) were horizontally sectioned 1 mm apical to the cementoenamel junction. The crowns were randomized into 8 experimental groups (calcium hydroxide, Ca[OH]₂; 1, 10, and 1,000 mg/mL TAP and DAP; and no medicament. The pulp chambers in half of the samples were coated with an adhesive bonding agent before receiving the intracanal medicament. Color changes (ΔE) were detected by spectrophotometry after 1 day, 1 week, and 4 weeks, and after 5,000 thermal cycles, with ΔE = 3.7 as a perceptible threshold. The 1-sample t-test was used to determine the significance of color changes relative to 3.7. Analysis of variance was used to evaluate the effects of treatment, adhesive, and time on color change, and the level of significance was p < 0.05. Results: Ca(OH)₂ and 1 and 10 mg/mL DAP did not cause clinically perceivable tooth discoloration. Adhesive agent use significantly decreased tooth discoloration in the 1,000 mg/mL TAP group up to 4 weeks. However, adhesive use did not significantly improve coronal discoloration after thermocycling when 1,000 mg/mL TAP was used. Conclusions: Ca(OH)₂ and 1 and 10 mg/mL DAP showed no clinical discoloration. Using an adhesive significantly improved coronal discoloration up to 4 weeks with 1,000 mg/mL TAP.

• 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.

• The Journal of the Korean dental association
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• v.11 no.3
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• pp.171-175
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• 1973

A 9-year-old girl, in good health, presented a horizontal impaction of the upper left central incisor. History revealed that the patient had been involved in a trauma of the maxillary anterior portion during her childhood. This impacted tooth crown, which was exposed surgically, was bonded by plastic attachments of direct bonding system, and was carefully tried to induce on the dental arch. On the process of the orthodontic treatment the tooth was completely induced and in normal alignment on the arch. The treatment result was very satisfactory; color, vitality, and mobility were normal, periodontal support was good and the cosmetic result was excellent.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.14 no.1
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• pp.15-18
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• 2005

In order to recover the esthetic of the missing anterior area, we must consider color, shape of a tooth and the functions of a prosthesis that is harmonized with the surrounding factors. When the tooth of a natural tooth is exposed, we face to challenge to restore them. several factors cause resorption of bones, in flammation, and gum trouble, and a defective prosthesis damages the aesthetics of the gingiva. There are two ways how to solve these problems. One can be done by periodontal surgery and the other can be done by prosthesis. Most patients want aesthetic restoration that is harmonized with their teeth and gingiva. So if prosthesis is fabricated to expose the root exposed, it is far from the patient's expectation.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2006.05a
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• pp.63-64
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• 2006

The design concept of this dental clinic Interior design is emotional color expression for the medical facility. This dental clinic is showing off the new adoption of the Korean primary traditional color pallette for the medical interior design. The graphic wall of the corridor is strongly attracting the eyes of customers while wrapping the corridor wall and partition with rather unconventional primary colored graphic shaping a tooth. Also the vivid and the dynamic atmosphere are emphasized by using the red color in the treatment area and the powder room. For the space programing, I focused on the functionality of each space and the efficiency of the traffic line. Centering around the information desk, the principal traffic line Is divided Into the staffs' private movement and the public movement.

• Restorative Dentistry and Endodontics
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• v.26 no.5
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• pp.399-408
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• 2001

Tooth bleaching has been prevailing recently for its ability to recover the color and shape of natural teeth without reduction of tooth material. However, it has been reported that bleaching procedure adversely affects the adhesive bond strength of composite resin to tooth. At the same time the bond strength was reported to be regained by application of some chemical agents. The purpose of this in vitro study was to investigate the effect of the removal of residual peroxide on the composite- enamel adhesion and also evaluated fracture mode between resin and enamel after bleaching. Sixty extracted human anterior and premolars teeth were divided into 5 groups and bleached by combined technique using of office bleaching with 35 % hydrogen peroxide and matrix bleaching with 10% carbamide peroxide for 4 weeks. After bleaching, the labial surfaces of each tooth were treated with catalase, 70% ethyl alcohol, distilled water and filled with composite resin. Shear bond strength was tested and the fractured surfaces were also examined with SEM. Analysis revealed significantly higher bond strength values. (p＜0.05) for catalase-treated specimens, but water-treated specimens showed reduction of bond strength, alcohol- treated specimens had medium value between the two groups(p＜0.05). The fracture mode was shown that the catalase group and the alcohol group had cohesive failure but the water sprayed group had adhesive failure. It was concluded that the peroxide residues in tooth after bleaching seems to be removed by gradual diffusion and the free radical oxygen from peroxide prevents polymerization by combining catalyst in the resin monomer. Therefore it may be possible to eliminate the adverse effect on the adhesion of composite resin to enamel after bleaching by using water displacement solution or dentin bonding agent including it for effective removal of residual peroxide.