• The Journal of Korean Academy of Prosthodontics
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• v.39 no.1
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• pp.37-48
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• 2001

Ceromers, new indirect resin system, are now being adopted for esthetic restorations. Despite of its translucency and good color matching, color stability after long-term use was unknown till now. This in vitro study was designed to evaluate color stability of some ceromers when subjected to brushing after thermocycling. Three types of ceromers: Scupture, Targis, Artglass and a direct resin system, Z100 were prepared to disks 12 mm in diameter, 2.5 mm in thickness. All specimens were polished, and Sculpture and Targis specimens were divided two groups, respectively. Then, half of them were glazed according to manufacturer's instructions. All specimen were brushed 20,000 times after 10,000 cycle thermocycling. Color was measured with spectrophotometer after 1,000, 3,000, 10,000 times thermocycling and 20,000 time brushing, respectively. Color difference (${\Delta}E$) was calculated according to CIE LAB system. During thermocycling, Sculpture & Targis system with polished surface showed greater color change than any other groups. After brushing, color difference was reduced significantly. Mean values of ${\Delta}E$ ranged 0.98 to 2.98. All Ceromers were considered clinically acceptable after thermocycling and brushing, and color change mechanism was affected by the brands and finishing methods. It might be concluded that color change of ceromer is due to surface alteration.

• Journal of Periodontal and Implant Science
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• v.32 no.1
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• pp.69-87
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• 2002

Implant material, implant design, surface quality, status of the bone, surgical technique, and implant loading conditions were regarded as prerequisites for osseointegration which is a prime condition for implant success. The aim of this review paper was to investigate the survival rate of single implants in relation to the prerequisites for osseointegration. Fifty-eight papers reporting survival rates of single implants were selected by use of the 'PubMed' and hand searching. The survival rate of single implants were assessed with reference to factors influencing osseointegration. The results showed that single implants in general showed a high survival rate except a few failures in certain extreme conditions and early stages. Those failures and complications such as screw loosening and esthetic problem were almost solved with the development of implant components and surgical techniques and a better understanding of biology around a single implant. Single-tooth implant-replacement is now considered as a reliable and predictable treatment option for a single missing tooth and its application seems to expand to compromised situations which were previously thought to be impossible for single implant therapy.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.2
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• pp.228-237
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• 2021

Physiologic tooth attrition is accepted as a natural change. But when pathologic changes, such as loss of occlusal vertical dimension, masticatory pain, loss of masticatory function, and loss of esthetics occur, restorative measures should be taken by dentist. A patient visited the clinic with the chief complaint of 'My lower teeth bite the palate and it hurts'. It was diagnosed as iatrogenic attrition of lower natural dentition caused by inappropriate upper restorations, resulting in traumatic overbite. Through model analysis and diagnostic wax up, increase in vertical dimension was decided. Upper and lower dentitions were restored with new prostheses. After restoration, satisfactory outcomes were achieved both in functional and esthetic aspects.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.1
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• pp.49-56
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• 2019

Generalized severely worn dentition causes occlusal disharmony, esthetic problems, and temporomandibular joint disorders. In order to solve these problems, it is necessary to make a precise analysis of vertical dimension and treatment plans considering it. This case report demonstrates the complete mouth rehabilitation of a 58-year-old male patient with a lot of worn teeth by increasing vertical dimension. Provisional restorations were cemented and after 4 months of evaluation for patient's compliance, permanent prostheses were fabricated. With these treatments, functionally and esthetically satisfactory results were obtained.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.3
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• pp.298-305
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• 2016

The maxillary anteriors play an important role in esthetics. Therefore after extraction, it is crucial to preserve the hard tissue and soft tissue in order to promote esthetics of restoration. There are several challenges when restoring the maxillary anteriors via implant. Some of the challenges are be maintaining consistency with neighboring teeth in terms of shade, form, and texture : as well as having harmonious emergency with the gingival margin. In this case, a traumatized patient with crown-root fracture of the maxillary central and lateral incisors is presented. The cracked teeth were extracted, and implants were inserted with bone grafts to compensate the volume of damaged area of the maxillary anterior. Cantilever implant prosthetics were planned while precise adjustments to the gingival area were made using customized impression coping to perform the esthetic restorations. The final outcome of the treatment was satisfying in both esthetic and utilitarian perspective.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.3
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• pp.520-529
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• 2003

Proper finishing and polishing of tooth restorations enhance the esthetics and the longevity of the restored tooth. The aims of this study were to identify an appropriate polishing system for each esthetic restorative material(Z250, Heliomolar, Dyract AP, Fuji II LC), and to compare the efficiency of polishing systems(Enhance, Sof-Lex, Composite). The control group remains untouched. The results were as follows: 1. There was no significant difference of surface roughness among the materials, while a roughness value of Z250 was the lowest of all. 2. The smoothest surface was produced by Mylar sheet on all materials. The polishing procedures, however, increased a roughness value. 3. The smoothest surfaces were produced by Sof-Lex, and there was significant difference of surface roughness between Sof-Lex and Enhance systems. 4. The smoother surfaces on the control group showed many scratches after the polishing procedures in the SEM findings.

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.4
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• pp.291-298
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• 2017

It is challenging to produce esthetic implant restoration in the narrow anterior maxilla region where insufficient volume of alveolar bone could limit the angle and position of implant fixture, if preceding bone augmentation is not considered. Ideal angle and position of implant fixture placement should be established to reproduce harmonious emergence profile with marginal gingiva of implant prosthesis, bone augmentation considered to be preceded before implant placement occasionally. In this case, preceding bone augmentation has been operated before esthetic implant prosthesis in narrow anterior maxilla region. Preceded excessive bone augmentation in buccal area allowed proper angulation of implantation, which compensates unfavorable implant position. Provisional restorations were corrected during sufficient period to make harmonious level of marginal gingiva and interdental papilla. The definite restoration was fabricated using zirconia core based glass ceramic. Functionally and esthetically satisfactory results were obtained.

• Journal of Technologic Dentistry
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• v.31 no.1
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• pp.23-36
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• 2009

The goal of esthetic restoration is to achieve morphologic, optical, and biologic acceptance. Creation of a natural looking ceramic restoration, which blends harmoniously with surrounding dentition, is not always achieved. A successful color match is an important aspect of any esthetic dental restoration. Since natural enamel has inherent translucency, it is important that ceramic restorations reproduce the translucency and color of the natural teeth. However, the final color match of porcelain crowns to adjacent natural dentition remains some problem. Difficulties related to color matching arise from the structural differences that exist between metal ceramic crowns and natural teeth, the limited range of available ceramic shades, inadequate shade guides, different types of metal alloys, repeated firing, the condensation technique, and varying compositions of ceramic materials. Many factors contribute to the esthetic success of dental restoration: optical properties such as color and its elements of hue, value, and chroma; translucency and opacity; light transmission and scattering; and metamerism and fluorescence. The purpose of this study was to determine the color changes of metal-ceramic system with different veneering porcelain powder after repeated firing. The objectives of this in vitro study were to measure the lightness($L^*$), chromaticity($a^*$), chromaticity($b^*$), chroma($C^*$), hue(h), reflectance(%), color difference(${\Delta}E$). The following conclusions were obtained: 1. An increase in the number of firings resulted in decrease in lightness($L^*$) but increase in chromacticity($a^*$) with all porcelain. After the second sintering resulted in decrease in chromacticity($b^*$) with opaque-dentin porcelain and dentin porcelain but in increase with enamel porcelain and translucency porcelain. And after the second sintering resulted in decrease in chroma($C^*$) with opaque-dentin porcelain and dentin porcelain, but on the whole side in decrease with enamel porcelain and translucency porcelain. 2. After the second firing, a increase in the number of firings resulted in decrease reflectance(%) in all wavelength. 3. There were noticeable color differences(${\Delta}E$) between first sintering and multiple firings(dentin porcelain: 5.29~8.15, opaque-dentin porcelain: 4.83~8.2, enamel porcelain: 8.93~13.15, translucency porcelain: 9.37~12.91), but the color difference(${\Delta}E$) after second sintering were down to 4.87 in all porcelain. 4. Given the NBS Criteria, a 'trace' was not found this study but a 'slight' was found 2-3, 3-5 in dentin porcelain, 2-3 in opaque-dentin porcelain, 3-5, 5-10 in enamel porcelain and translucency porcelain, a 'noticeable' was 2-5, 3-10, 5-10 in dentin porcelain and opaque-dentin porcelain, 2-3, 2-5, 3-10 in enamel porcelain 2-3, 3-10 in translucency porcelain, an 'appreciable' was 1-2, 1-3, 2-10 in dentin porcelain 1-2, 1-3, 2-10, 3-10 in opaque-dentin porcelain, 2-10 in enamel porcelain, 2-5, 2-10 in translucency porcelain, a 'much' was 1-5, 1-10 in dentin porcelain and opaque-dentin porcelain, 1-2, 1-3, 1-5 in enamel porcelain 1-2, 1-3, 1-5, 1-10 in translucency porcelain, a 'very much' was 1-10 in enamel porcelain.

• The Journal of Korean Academy of Prosthodontics
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• v.51 no.1
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• pp.39-46
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• 2013

The loss of posterior support may cause attrition of anterior teeth, and loss of occlusal vertical dimension (OVD). The collapse of the posterior support will eventually cause the pathologic change of the TMJ and masticatory muscles, unesthetic facial appearance and decreased masticatory function. Patients with destroyed dentition need extensive prosthetic treatments. Proper diagnosis and treatment planning are necessary for the stability of the neuromuscular system and the TMJ, and esthetic and functional definitive restorations. In this case, 63 year-old male presented with decreased masticatory force and esthetic problems due to pathologic destruction of teeth structure on entire dentition. Based on assessment of OVD including intraoral findings, radiographic examination and diagnostic cast, full-mouth rehabilitation with increase of OVD was planned using fixed partial denture and removable partial denture. Diagnostic wax-up was done after 4 mm increase of OVD determined by assessment of OVD. The OVD was maintained with the overlay type removable interim prostheses for 12 weeks to ascertain his comfort and adaptation to the new OVD. After the adaptation period, second interim prostheses with tooth preparation maintaining the established OVD was delivered. After 4 weeks, final prostheses were fabricated and delivered. After 7 month follow-up period, occlusal stability is maintained. Through this procedure, satisfactory outcomes were achieved both in functional and esthetic aspects.

• Restorative Dentistry and Endodontics
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• v.24 no.4
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• pp.585-603
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• 1999

Esthetic availabilities used as an esthetic restorative maternals can be determined by the optical coincidence among materials, enamel and dentin. Enamel is highly translucent. That's why esthetic materials need to correspond the close translucency of enamel. But the translucent materials are affected by the background color. So it should be predicted that the color of estorative materials depend on the any thickness and the spectral reflectance of the background on which they are placed. The object of this investigation, under above hypothesis, was to determine and analyze how they affect the final color according to the thickness, translucency and background color (white, black and dentin) fill three commercial light cured composite resins(Charisma, Spectrum TPH and Z100). And correlation was analyzed to find out the possibility of the prediction when using the certain background color and thickness of materials. Followings are the result 1. The I shade of CHA showed the lowest contrast ratio($Co_7$) while the B3 shade of Z100 showed the highest contrast ratio(p<0.05). 2. The value of $L^*$ and $b^*$ on the white and dentin background is increased with decreasing thickness. And there are significant relationships between increasing thickness and each value(R>0.085). But there is a little change of $L^*$ and $b^*$ value on the black background regardless of the thickness(p>0.05). 3. For the $a^*$ value, there was little difference in values as a function of thickness and changed irregularly regardless of thickness in all background. 4. The pattern of increasing value of $L^*$ and $b^*$ with decreasing thickness was similar to the group of white and dentin background. In both dentin one showed lesser change of value. 5. The values of $L^*a^*b^*$ measured on the different background with same thickness showed the recognizable color difference(${\Delta}E^*$>2) when the thickness was below 2.6mm. 6. Contrast ratio was increased with increasing thickness with significant relationship (R>0.9). 7. Spectral reflectance of composite resins that calculated from Kubelka-Munk equation was showed little difference compared with observed value w1th decreasing thickness.