• 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.

• Restorative Dentistry and Endodontics
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• v.43 no.1
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• pp.9.1-9.6
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• 2018

The objective of this case report is to introduce a simple technique for simultaneously taking a closed-mouth impression and functionally generated path (FGP) for a full coverage crown restoration. A monolithic zirconia crown was the restoration of choice. An alginate impression of the abutment tooth was taken to fabricate a custom-made closed-mouth impression tray covering the abutment tooth and the adjacent teeth. The tray had an FGP table and an abutment tray in cameo and intaglio surfaces, respectively. The impression was taken with silicone impression material after adjusting the abutment tray and inscribing the FGP using self-curing acrylic resins. Plaster casts were made from the impression, and a zirconia crown was fabricated. The crown was cemented to the abutment tooth with minimal adjustments. This simple technique resulted in a well-fitting crown that accounted for mandibular movements. Using the custom closed-mouth impression tray incorporating an FGP table simultaneously aids in fabricating an accurately fitting restoration that incorporates harmonious mandibular movements using a single impression capture.

• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.3
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• pp.224-231
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• 2016

Severe dental attrition causes pathological changes of the tooth, imbalanced occlusion, and functional and aesthetic complications and can also result in a decrease in occlusal vertical dimension that can incur temporomandibular joint and muscular complications. Before restoring the vertical dimension with full-mouth prosthetic restorations, it is important to determine the amount of vertical lifting through complete diagnosis. In this study, a 59 year-old male patient with generalized attrition and fracture of teeth was treated with full-mouth zirconia prosthetic restoration in order to recover vertical dimension and aesthetics. Through the analysis of physiologic rest position and inter-canine distance, the treatment was planned for lifting 3 mm in vertical dimension. Interim crown were fabricated after full-mouth wax up, having the patient use for 6 months. The final monolithic and bilayered zirconia restorations were completed. The patient showed satisfaction in function and aesthetics for 18 months of follow-up since delivering the final restorations.

• The Journal of Advanced Prosthodontics
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• v.16 no.4
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• pp.231-243
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• 2024

PURPOSE. The objective of the study was to analyze the impact of cement, bonding pretreatment, and ceramic abutment material on the overall color results of CAD-CAM ceramic crowns bonded to titanium-based hybrid abutments. MATERIALS AND METHODS. For single implant restoration of a maxillary lateral incisor a total of 51 CAD-CAM-fabricated monolithic lithium disilicate crowns were fabricated and subsequently bonded onto 24 lithium disilicate Ti-base abutments, 24 zirconia Ti-base abutments and 3 resin abutment replicas as a control group. The 48 copings were cemented with three definitive and one provisional cement on both grit-blasted and non-blasted Ti-bases. The color of each restoration and surrounding artificial gingiva was measured spectrophotometrically at predefined measuring points and the CIELAB (ΔE_ab) color scale values were recorded. RESULTS. The color outcome of ceramic crowns bonded to hybrid abutments and soft tissues was affected differently by cements of different brands. Grit-blasting of Ti-bases prior to cementing CAD-CAM copings affected the color results of allceramic crowns. There was a significant difference (P = .038) for the median ΔE value between blasted and non-blasted reconstructions at the cervical aspect of the crown. Full-ceramic crowns on zirconia Ti-base abutments exhibited significantly lower ΔE values below the threshold of visibility (ΔE 1.8). In all subcategories tested, the use of a highly opaque temporary cement demonstrated the lowest median ΔE for both the crown and the artificial gingiva. CONCLUSION. Various cements, core ceramic materials and airborne particle abrasion prior to bonding can adversely affect the color of Ti-base supported ceramic crowns and peri-implant soft tissue. However, zirconia CAD-CAM copings and an opaque cement can effectively mask this darkening.

• The Journal of Korean Academy of Prosthodontics
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• v.55 no.2
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• pp.156-163
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• 2017

People with class I intellectual disability need lifelong assistance and protection from their surroundings due to impaired adaptive functioning. They have poor oral health and show higher prevalence of dental caries, periapical inflammation and tooth loss that require proper prosthetic restoration. Because removable prostheses for intellectually disabled patients often lack stability, retention, and maintenance, fixed prostheses are essential and the only available option is dental implants. In this case, a 45 year-old male patient with class I intellectual disability had poor oral hygiene with most of his teeth missing and visited the clinic to recover his masticatory function. Due to such systemic conditions, the definitive restoration of choice was the implant-supported fixed dental prosthesis made of biocompatible and highly strong monolithic zirconia. In consequence of the treatment process, the patient was able to improve his oral environment aesthetically and functionally.

• The Journal of Korean Academy of Prosthodontics
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• v.62 no.4
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• pp.328-338
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• 2024

Advancements in CAD-CAM technology have allowed for a variety of options in implant-supported fixed prosthesis restorations for completely edentulous patients. For patients with severe alveolar bone resorption, zirconia prosthetic restorations that include the gingival portion, such as implant-supported hybrid dentures, are possible, as well as monolithic zirconia prosthetic restorations in the form of crowns. The integration of digital technology in fixed prosthetic restoration using implants enables predictable treatment through diagnosis and virtual surgery by integrating the patient's clinical and radiological information. In this case, the utilization of digital software allowed for the establishment of implants in appropriate positions, considering both the remaining alveolar bone and the final prosthesis. By designing both the maxillary removable prosthesis and the mandibular fixed prosthesis simultaneously in CAD software, bilateral balanced occlusion could be easily achieved. Furthermore, maintaining the initial interocclusal relationship from provisional restorations to final prostheses allowed for convenient transition while ensuring functional and aesthetic satisfaction.

• Journal of Korean society of Dental Hygiene
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• v.22 no.4
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• pp.225-230
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• 2022

Objectives: Patients with excessive tooth wear should first be diagnosed for the etiology of the tooth wear. Causes of tooth wear include bruxism, clenching, and taking medications for systemic diseases. After identifying the cause of tooth attrition, the final prosthesis should be restored with an appropriate vertical dimension. Methods: A 79-year-old man with worn out teeth desired a whole dental treatment. He was on medications for high blood pressure and asthma. The treatment proceeded with a consultation with a medical doctor. The medications for asthma evoked multiple teeth wear and a loss of the vertical dimension. After recovery of 3 mm of vertical dimension, 2 months of evaluation was followed by an interim prosthesis. Results: The increased vertical dimension caused no problem in function and esthetics, and the final restoration was performed with a full monolithic zirconia crown. Group function, adequate anterior guidance, and the occlusal plane were determined. Conclusions: After the final restoration, the patient was both esthetically and functionally satisfied, and a night guard splint was delivered to prevent prosthesis fracture. The patient was informed about the potential tooth wear associated with asthma drugs and educated to visit the clinic regularly.

• Journal of Dental Rehabilitation and Applied Science
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• v.36 no.1
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• pp.41-47
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• 2020

Purpose: The purpose of this study was to evaluate the flexural strength and reliability of highly translucent colored zirconia for all ceramic restoration. Materials and Methods: Bar-shaped specimens (25 × 4 × 2.5 mm) were prepared from highly translucent monolithic zirconia. Three experimental groups were set up according to color (shade A0, A1, and A3). For each group, 20 specimens were prepared. Flexural strength was determined using a 3-point flexural test and results were analyzed with one-way ANOVA test. Weibull statistical analysis provided 2 parameter estimates: Weibull modulus and characteristic strength. X-ray diffraction (XRD) analysis was performed. Results: There was statistically significant difference between uncolored (Shade A0) and colored (shade A1 and A3) (P < 0.05), but there was no difference between colored groups (P > 0.05). The uncolored group had higher reliability compared with colored study groups. On x-ray diffraction analysis of each group, typical peaks of tetragonal phase appeared in all groups. Conclusion: Within the limitations of this in vitro study, coloring highly translucent zirconia had significant effect on flexural strength and reliability. Therefore, clinicians should be careful when using highly translucent colored zirconia to prevent breakage of veneering ceramic and enhance aesthetics.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.1
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• pp.91-99
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• 2022

Severely worn dentition causes various complications such as loss of tooth structure, discoloration, pulp complications and loss of function and aesthetics. In this case, the patient showed particularly severe attrition in the anterior teeth and lack of space for restoration. The amount of vertical dimension was determined based on the diagnostic wax up, and the patient's adaptation was evaluated by using a removable occlusal splint for 6 weeks. Thereafter, the coordination of the muscular nervous system, aesthetics, temporomandibular joint were re-evaluated for 3 months by restoring the fixed provisional restoration. Through the above treatment process, the final restoration was completed with full mouth fixed prosthesis using monolithic zirconia, and functionally and aesthetically stable results were obtained.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.2
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• pp.121-129
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• 2020

From the point of view of oral rehabilitation, the treatment of extensive tooth wear requires a prosthetic approach. Physiological tooth wear is considered as a normal process and generally does not require treatment, but excessive tooth wear causes problems like inadequate occlusion and esthetics. Changes of occlusal vertical dimension should be made through accurate diagnosis and analysis. Also, the patient's adaptation to the changed occlusal vertical dimension should be assessed over time. This case was a 60-year-old male patient who complained of a decrease in chewing function and esthetics due to severe tooth wear. Full-mouth rehabilitation was performed with a tooth supported fixed prosthesis. An occlusal stabilization splint and provisional restoration were used to evaluate the adaptation to increased occlusal vertical dimension and induce a stable centric relation position. After that, monolithic zirconia prosthesis was delivered. We report this as a satisfactory functional recovery and esthetics.