• Journal of Periodontal and Implant Science
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• v.31 no.2
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• pp.269-276
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• 2001

The purpose of this study was to evaluate the clinical validity of multi-rooted teeth subjected to root-resection treatment. Over a period of 1-7 years, 60 root-resected molars in 59 patients were examined clinically and radiographically. All patients were p0eriodically recalled once or twice a year. Root-resections were due to periodontal, more specifically furcal bone loss or marginal bone loss,in 34 cases and extensive dental carious destruction in 10 cases. In other cases,root-resections resulted from 6 cases of root fracture, 6 cases of periodontal-endodontic combined lesion, and 1 case of endodontic problem. Root-resection was carried out on 26 maxillary molars and 34 mandibular molars. The results are as follows; 1. 14 cases(23.3%) were considered failures. 8 cases(13.3%) of them occurred within the first year(8 cases, 13.3%), 4 cases(6.7%)between 1-3 years, and 2 cases(3.3%) between 4-7 years. 2. 8 cases(13.3%) were considered failures due to periodontal reasons, 3 cases(5%) due to root fracture, 2 cases(3.3%) due to endodontic problem, and 1 case(1.7%) due to prosthetic problem. 3. 37 cases(61.7%) showed up for the recall appointments, and the percentage of failures(13.5%) was lower compared with that of all patients(23.3%). The results of the present study indicate that the prognosis of root-resected teeth is favourable if attention is paid to the selection of proper case and to achieving optimal oral hygiene and periodic check up.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.4
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• pp.442-450
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• 2021

The CAD-CAM technique is a rapidly developing field in the dental field and is applied to various fields of prosthetic treatment. Among them, the manufacturing of dentures using the milling technique classified as subtractive manufacturing is one of the commercialized digital full denture manufacturing methods. At the same time, it is possible to more efficiently manufacture a metal framework for implant overdenture by selective laser sintering or melting technique classified as an additive manufacturing method. The purpose of this article is to describe the fabrication of CAD-CAM maxillary complete denture and mandibular implant overdenture as well as its features.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.4
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• pp.317-323
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• 2018

When oral cancer develops in the maxilla, oro-nasal communication occurs after surgical treatment including removal of the primary site. Restoration through an obturator is necessary to prevent food from storing due to non-oral opening, and to ensure proper pronunciation and aesthetic restoration. In this case, the patient was treated with right hemi-maxillectomy due to oral cancer and has residual abutment and poor periodontal support due to the effect of head and neck radiotherapy. The obturator was treated with a hybrid telescopic double crown denture. Reporting a successful prognosis in 18 months of follow-up.

• Journal of Dental Rehabilitation and Applied Science
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• v.35 no.3
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• pp.191-198
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• 2019

This case report presents a closed hollow bulb obturator made by 3D printing for a maxillectomy patient. Final impression was taken according to the instructions and impression trays provided by the Magic $denture^{TM}$ system. Vertical dimension, facial appearance, and retention had been checked with the try-in denture. The try-in denture was corrected and adjusted to fulfill the demand of the patients, then these were reflected to the final design of the denture. The defect area was designed as a closed hollow bulb shape to reduce the weight and to provide uniform thickness of the denture. The patient satisfied with the esthetics and function of the denture.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.2
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• pp.195-201
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• 2022

Hemimandibulectomy and free fibular flap (FFF) in patients with squamous cell carcinoma could disturb the functional movement of the mandible. The muscular function in the sectioned side was compromised because of the incompetency of the muscle attachment to the mandible, leading to the unstable occlusal contact in the centric and eccentric occlusion. In this report, we present a case of a 63-year-old male who underwent cancer surgery and reconstruction with fibular graft, and he needed a fixed dental prosthesis to restore tooth loss in the anterior region. Occlusal contact change and instability were found according to the bite force in the centric relation and eccentric movement. This case report aimed to present the prosthetic procedure for fabricating the functionally optimized fixed prosthesis wherein the functionally generated path (FGP) technique and digital imaging method were applied to replicate mandibular movement and vertical dimension of the patient.

• Journal of Dental Rehabilitation and Applied Science
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• v.38 no.3
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• pp.162-170
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• 2022

In the case of patients with pathological tooth wear, it is necessary to evaluate the loss of the vertical dimension. Setting the appropriate vertical dimension is important to rehabilitate the patient's stable intermaxillary relationship. A 77-year-old female patient's chief complaint was the pain of the mandibular incisors and the lack of molars. At the first visit, pathologic tooth wear of the mandibular incisors were observed. After diagnosis and evaluation, loss of vertical dimension was not observed, but insufficient intermaxillary space for prosthetic restoration was confirmed. Mandibular rehabilitation was performed with vertical dimension increase and this showed satisfactory results both functionally and aesthetically.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.1
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• pp.29-36
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• 2022

When planning oral rehabilitation for maxillary edentulous patients, fixed prosthetic restoration using implants, complete denture restoration or overdentures using implants can be considered as treatment methods. In the case of complete denture restoration, it does not require additional surgery and is relatively economical. In the case of implant-supported fixed prostheses, the functional part is generally superior to that of complete denture restoration, but there are cases in which implant placement is clinically difficult. Recently in consideration of the patient's needs and the condition of the remaining alveolar bone, after partial implant placement, a method of restoring with a removable partial denture using implant-supported surveyed crown is also being attempted. This case is a case of performing a removable partial denture restoration using implant-supported surveyed crown in the anterior maxilla, and showing satisfactory esthetic and functional results.

• The Journal of Advanced Prosthodontics
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• v.14 no.5
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• pp.294-304
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• 2022

PURPOSE. The purpose of this study was to evaluate the influence of different palatal vault configurations on the accuracy and scan speed of intraoral scans (IO) of completely edentulous arches. MATERIALS AND METHODS. Three different virtual models of a completely edentulous maxillary arch with different palatal vault heights- Cl I moderate (U-shaped), Cl II deep (steep) and Cl III shallow (flat)-were digitally designed using CAD software (Meshmixer; Autodesk, USA) and 3D-printed using SLA-based 3D-printer (XFAB; DWS, Italy) (n = 30; 10 specimens per group). Each model was scanned using intraoral scanner (Trios 3; 3Shape^TM, Denmark). Scanning time was recorded for all samples. Scanning accuracy (trueness and precision) were evaluated using digital subtraction technique using Geomagic Control X v2020 (Geomagic; 3DSystems, USA). One-way analysis of variance (ANOVA) test was used to detect differences in scanning time, trueness and precision among the test groups. Statistical significance was set at α = .05. RESULTS. The scan process could not be completed for Class II group and manufacturer's recommended technique had to be modified. ANOVA revealed no statistically significant difference in trueness and precision values among the test groups (P=.959 and P=.658, respectively). Deep palatal vault (Cl II) showed significantly longer scan time compared to Cl I and III. CONCLUSION. The selection of scan protocol in complex cases such as deep palatal vault is of utmost importance. The modified, adopted longer path scan protocol of deep vault cases resulted in increased scan time when compared to the other two groups.

• Korean Journal of Materials Research
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• v.33 no.8
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• pp.337-343
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• 2023

3Y-TZP (3 mol% yttria-stabilized tetragonal zirconia polycrystals) ceramics have excellent mechanical properties including high fracture toughness, good abrasion resistance as well as chemical and biological stability. As a result, they are widely used in mechanical and medical components such as bearings, grinding balls, and hip implants. In addition, they provide excellent light transmittance, biocompatibility, and can match tooth color when used as a dental implant. Recently, given the materials' resemblance to human teeth, these ceramics have emerged as an alternative to titanium implants. Since the introduction of CAD/CAM in the manufacture of ceramic implants, they've been increasingly used for prosthetic restoration where aesthetics and strength are required. In this study, to improve the surface roughness of zirconia implants, we modified the 3Y-TZP surface with a biocomposite of hydroxyapatite and forsterite using room temperature spray coating methods, and investigated the mixed effect of the two powders on the evolution of surface microstructure, i.e., coating thickness and roughness, and biological interaction during the in vitro test in SBF solution. We compared improvement in bioactivity by observing dissolution and re-precipitation on the specimen surface. From the results of in vitro testing in SBF solution, we confirmed improvement in the bioactivity of the 3Y-TZP substrate after surface modification with a biocomposite of hydroxyapatite and forsterite. Surface dissolution of the coating layer and the precipitation of new hydroxyapatite particles was observed on the modified surface, indicating the improvement in bioactivity of the zirconia substrate.

• The Journal of Korean Academy of Prosthodontics
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• v.61 no.4
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• pp.328-343
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• 2023

Recently, a method of fabricating an esthetic anterior fixed prosthesis by integrating data such as three-dimensional facial scan and jaw motion to form a virtual patient with dynamic occlusion has been introduced. This enables smooth communication with patients during the diagnosis process, improves the predictability of esthetic prosthetic treatment, and lowers the possibility of occlusal adjustment. In this case report, a virtual patient with dynamic occlusion was created in which the results of the treatment were simulated, and esthetic maxillary anterior fixed prosthesis was fabricated. With the aid of the virtual patient, the final restorations were satisfactory both in terms of esthetic and function.