• Journal of the Korean Academy of Esthetic Dentistry
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• v.25 no.2
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• pp.79-87
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• 2016

Single visit monolithic restoration can be proceed with digital workflow which consist of intraoral scanning, dental CAD(computer aided design) and restoration milling with CAM(Computer aided manufacturing). While zirconia has more than 900MPa of flexural strength compared with 400MPa for lithium disilicate, shortened fabricating time of lithium disilicate is considered to be a better choice for fabricating single visit full contour monolithic restoration. However, new zirconia materials which are TZI C(Dentsply Sirona) and LUXEN Enamel(Dental Max), new induction heating method of sintering furnace, and new sintering protocols for MoSi2 heating elements sintering furnace offer significantly reduction of full contour monolithic zirconia restoration fabrication time with greater translucency. These new developments lead single visit zirconia restoration in reality.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.3
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• pp.293-300
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• 2022

Various materials and restorative options have been introduced recently with growing interest in esthetic dental treatment in modern society. Zirconia is especially known for its biocompatibility as well as remarkable toughness and resistance to wear, but it is limited in its use for esthetically focused treatment in anterior region for its white opacity. Lately the development of different kinds of zirconium blocks, such as colored block, clear block, and multi-layered block, allowed more extensive use of zirconia as a treatment option. This report describes a case, in which a prosthetic crown maxillary anterior region was stained with a combination of various coloring liquids before sintering to reproduce natural-looking color scheme in final restoration. The case was reported as the utilization of coloring liquid on monolithic zirconia crown could achieve esthetically satisfying prosthesis for both dentist and patient.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.4
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• pp.352-358
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• 2014

They have been recently introduced many aesthetic implant prosthesis using with zirconia and CAD/CAM. However, there are many limitations in their gingival and occlusal region. In this case, submucosal zirconia implant prosthesis were fabricated with CAD/CAM system. The connection of these screw cement retained prosthesis and titanium abutment was designed to 1mm above the fixture. The clinical results were satisfactory on the aesthetics and function.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.374-381
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• 2019

A conventional approach for the treatment of long-span edentulous areas is the use of removable dentures. However, placing implants in these areas results in superior functional outcomes by increasing the stability, support, and resistance of the prostheses and improving the masticatory efficiency. Treatment modalities utilizing implants can be further classified into either removable or fixed-type prostheses. Several factors such as the amount of alveolar bone resorption, inter-arch relationship, patient preferences, and socioeconomic status should be considered when determining the appropriate treatment approach. Monolithic zirconia has been considered a suitable material for implant-supported fixed dental prosthesis, because of the drastic improvement in its mechanical properties. It exhibits fewer incidences of fracture and chipping of the prostheses, and has greater bulk of material than metal-ceramic crowns and zirconia-veneered ceramics. Moreover, highly translucent monolithic zirconia is also available in the market, and its application is gradually increasing for anterior tooth rehabilitation. The present report describes a patient who underwent full-mouth rehabilitation with fixed dental prostheses (eight upper and three lower implant placements). All teeth, except bilateral mandibular canines and left mandibular first and second premolars, were extracted after the diagnosis of generalized chronic moderate-to-advanced periodontitis of the remaining teeth. The patient reported satisfactory esthetic and functional outcomes during the one-year follow-up visit.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.4
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• pp.469-477
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• 2021

For successful restoration of maxillary anterior implants, both pink esthetics and white esthetics must be satisfied. For pink esthetic part, the role of appropriate provisional prosthesis restoration is important, and for white esthetic part, the color and shape of the definitive prosthesis is important. Multilayer zirconia can be used for natural tooth appearance due to the higher transparency of the incisal area compared to the conventional monolithic zirconia. Therefore, in this case, white esthetic part was achieved through multilayer zirconia after recovering function and esthetics through appropriate provisional prosthesis in a patient who lost the maxillary anterior teeth.

• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.4
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• pp.177-185
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• 2021

Clinical applications of translucent zirconia as well as traditional zirconia (3 mol% yttria stabilized tetragonal zirconia polycrystal, 3Y-TZP) are increasing. For this reason, studies on factors affecting the optical properties of dental zirconia have been continuously reported. The optical effect of dental zirconia may vary depending on the yttria content, the thickness of the prosthesis, the sintering process, polishing, glazing and cementation in laboratory and clinical procedures. Increasing the yttria concentration can reduce the masking effect. Translucency decreases as the thickness of the restoration increases, but the required thickness may vary depending on the properties of the zirconia block. The high-speed sintering method can shorten the manufacturing time, but in some cases, the translucency of the prosthesis may decrease. In addition, the optical properties can be affected by the surface roughness of zirconia and the polishing process. The use of an appropriate colored cement can help with the masking effect of zirconia and can be useful for color matching for more esthetic results.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.3
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• pp.217-220
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• 2020

Conventionally, when a zirconia fixed dental restoration is planned, the interim restoration is made manually and the final restoration is fabricated by the silicone impression taking at the prosthodontic stage. This conventional workflow does not provide direct relation between interim and final restorations. Moreover, the predictability of the final restoration could be low. Nowadays, the CAD/CAM based restoration fabrication and related digital techniques are developed and being applied in dentistry in multiple ways. This case report introduces a digital workflow for fabricating an optimal gingival adaptation and predictability of monolithic zirconia restoration by using CAD/CAM interim restoration, intra oral scan, and image superimposition technique in a case that required tooth extraction.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.32 no.1
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• pp.4-7
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• 2023

Since the end of the 1990s, zirconia, which has been applied to dental prostheses, has been used in the form of coping or framework. The prostheses made in this way have been successfully used in the anterior teeth because they have no metal components as a structure. But in the posterior teeth, its use was limited due to the fracture or chipping of the veneering porcelain during the function. Later, as a solution to this shortcoming, a monolithic zirconia restoration was proposed in which a strong coping material was used in the form of a complete prosthesis. But, this resulted in some unesthetic results due to the characteristics of zirconia, which has excellent resistance to strong forces but is very white and opaque. However, now, due to technological advances in increasing the translucency of zirconia, it is possible to produce strong and esthetic zirconia restorations not only in the posterior region but also in the anterior region. In this article, the structural characteristics of various types of zirconia materials that have been developed so far, were discussed, and where the zirconia products actually in use belong to was explained.

• The Journal of Korean Academy of Prosthodontics
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• v.55 no.2
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• pp.135-143
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• 2017

Purpose: This research was conducted to compare the marginal and internal fit of zirconia prostheses fabricated with the model scan method and the intraoral scan method. Materials and methods: In this study, 20 extracted human mandibular first molar was used in the preparation of abutment tooth for the fabrication of zirconia prostheses. In the first group, the model scan method was applied on 10 prepared teeth. In the other group, the intraoral scan method was used on other 10 prepared teeth. Datum of both groups were transmitted to the software system. Afterwards, 20 zirconia prostheses were fabricated using the Ceramill system. Weight technique was used to evaluate the internal gap of the zirconia prostheses. In the Replica technique, marginal gap of the zirconia prostheses were analyzed by optical microscopy. Statistical analysis was based on one-way ANOVA. Results: Model scan group showed lower average weight than intraoral scan group when weight technique was applied, which has significance (P < .05). Also, model scan group showed significantly lower figures in all 5 measurements of replica technique than intraoral scan group (P < .05). Conclusion: Zirconia prostheses of both groups demonstrated clinically acceptable margin and internal fit. However, model scanned zirconia prostheses showed higher marginal and internal fit than intraoral scanned crowns.

• The Journal of Korean Academy of Prosthodontics
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• v.55 no.1
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• pp.26-31
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• 2017

Purpose: This study was to assess clinically the success rates and technical complications of cement-retained implant-supported single crowns and splinted crowns with zirconia frameworks. Materials and methods: 75 (single crowns: 51, splinted crowns: 24) cement-retained implant-supported single crowns and splinted crowns with zirconia frameworks which were restored in 67 patients were investigated for the evaluation of the success rates and technical complications. All restorations were cemented with temporary cement. Age, gender, restoration position, opposing teeth, restoration type were assessed as possible factors affecting technical complications. Results: During the mean observation period of 22.2 months, cumulative success rates of all restorations were 66.9 (73.2 - 60.6)%. Retention loss was found in 16 restorations (single crowns: 14, splinted crowns: 2), abutment screw loosening and veneer porcelain fracture were found in each 2 single crowns, respectively. According to a Kaplan-Meier survival analysis of single crowns and splinted crowns, the cumulative success rates were 58.9 (66.6 - 51.2)%, 87.5 (96.1 - 78.9)%, respectively. There was a statistically significant difference. The other possible factors did not have a significant effect on the technical complications. Conclusion: Retention loss was the most frequent technical complication. Abutment screw loosening and veneer porcelain fracture were found rarely in single crowns only. Age, gender, restoration position, and antagonist did not have significant effect on the technical complications. Splinted crowns had a higher success rate than single crowns.