• Journal of the Korea Computer Graphics Society
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• v.11 no.2
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• pp.1-8
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• 2005

하나의 치아가 일부 파손되어 수복되어야 할 보철물을 인레이/온레이(Inlay/Onlay)라 한다. 본 논문에서는 3차원 메쉬 기반 모델에서 보다 정확한 인레이/온레이를 효과적으로 모델링하기 위한 기법을 제안한다. 인레이/온레이는 지대치와 접하는 내면과 밖으로 들어나는 외면으로 구성된다. 인레이/온레이의 내면 모델링은 2차원 다각선상의 Minkowski Sum 알고리즘을 이용하여 지대치와의 접합력을 확보한다. 그리고 미리 데이터베이스에 저장된 표준 치아 모델, 치과의사에 의해 만들어진 FGP(functionally guided plane) 및 메쉬의 변형 기법인 DMFFD(direct manipulation free-form deformation) 기법[16]과 MWD(multiple wires deformation) 기법[24]을 이용하여 외면을 모델링한다. 데이터베이스에 저장된 표준 치아는 인레이/온레이 외면의 형태를 결정하기 위해 사용되며, FGP는 환자의 인접면과 교합면의 특성을 반영하기 위해 사용되었다. 마지막으로 3차원 메쉬의 두 변형 기법인 DMFFD와 MWD 기법은 환자의 인접면과 교합면을 반영한 치아의 형태를 만들어 내기 위해 사용된다. 본 논문에서 제안한 방법은 인레이/온레이의 내면과 외면을 설계할 때 필요한 정보를 미리 설정하여 처리하므로 기존의 방법에 비해 짧은 시간에 보다 정확한 인레이/온레이를 설계할 수 있었다.

• 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.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.1
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• pp.97-106
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• 2021

Dental implants should be placed at ideal sites for implant-supported restorations. For a patient with insufficient residual ridge, mouth preparation including surgical intervention can be indicated to establish a soft and hard tissue environment favorable for a definitive prosthesis. Prosthodontic design based on computer-guided surgery and computer-aided design-computer-aided manufacturing (CAD-CAM) provides a visual blueprint allowing a clinician to assess the necessity of such a surgical intervention beforehand. In this case, a definitive restoration was planned and made via a CAD-CAM system according to the patient's oral status before treatment, simulated surgical interventions and serial provisional restorations. Based on the planning, a guided template was made and the implants were installed with bone augmentation using the template. Customized abutments, the first and the second provisional restorations were designed and fabricated by CAD-CAM. The definitive restorations were digitally made following the shape of the second provisional prostheses, which were confirmed in the patient's mouth. The patient was satisfied with the masticatory, phonetic and aesthetic functions of these definitive prostheses.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.2
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• pp.121-127
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• 2014

Comprehensive prosthetic treatment requires considerations from various points of view. The anterior guidance is important factor in prosthodontic treatment of anterior teeth. Lingual surface contour of anterior restoration is so critical that a small mistake of laboratory or clinical process can cause discomfort of patient and disharmony of entire dentition. There are no guidelines for lingual surface contour that fit all patients. Therefore the lingual surface of provisional restoration is most accurately described as a customized one. The dentist transfers the exact information of anterior guidance that has made through long term provisional restoration to the technician. This case introduce that the duplication technique of CAD/CAM system to reproduce the anterior guidance of provisional restoration. This method can improve satisfaction of both patient and dentist.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.2
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• pp.176-181
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• 2019

Traditional removable partial denture is a successful treatment for partial edentulous patients. When the abutment is formed with unilateral minority teeth, satisfaction with the use of removable partial denture may be lowered due to patient's discomfort and damage of the abutment. Recently, it has been reported that the unilateral posterior extension partial denture is used as a bilateral posterior extension partial denture using implant fixed prostheses as abutments. In this case, by using implant surveyed crown prostheses, bilateral posterior extension partial denture is fabricated in site that is predicted to have a poor prognosis. This resulted in improved support, maintenance, and stabilization of the removable partial denture, which were economically beneficial to patient and satisfied with use.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.3
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• pp.224-235
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• 2013

A passively fitting prosthesis is an essential prerequisite to attain long-lasting success and maintenance of osseointegration. However, true "passive fit" can not be achieved with the present implant-supported prosthesis fabrication protocol. Many clinical situations are suitably treated with cantilevered implant-supported fixed restorations. The purpose of this study was to compare the stress distribution pattern and magnitude in supporting tissues around ITI implants with cantilevered, implant-supported, screw-retained fixed prosthesis according to the fitness of superstructures. Photoelastic model was made with PL-2 resin (Measurements, Raleigh, USA) and three ITI implants (${\phi}4.1{\times}10mm$) were placed in the mandibular posterior edentulous area distal to the canine. Anterior and posterior extended 4-unit cantilevered FPDs were made with different misfit in the superstructures. 4 types of prosthesis were made by placing a $100{\mu}m$ gap between the abutment and the crown on the second premolar and/or the first molar. Photoelastic stress analysis were carried out to measure the fringe order around the implant supporting structure under simulated loading conditions (30 lb).

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.3
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• pp.252-257
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• 2014

It is important to produce a provisional restoration reflecting the patient's jaw relation, occlusal plane, lip support, shape of teeth, and occlusion type for fully edentulous patients before making a definite prosthesis. The patient introduced in this study showed bad prognosis of remained tooth after severe periodontal diseases. Therefore, remaining teeth were extracted and replaced with dental implants. Provisional restorations were fabricated and the the patient's vertical and horizontal jaw relationship, occlusal plane, amount of overjet and overbite, size of teeth, and length of anterior tooth were recorded. Provisional restorations were scanned and CAD/CAM techniques were used to fabricate a monolithic zirconia bridge, which contour is identical with the provisional restorations. The patient was satisfied with the treatment results on functional, esthetic aspects and the prosthesis retained stable during the four-month clinical observation period.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.397-404
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• 2019

Bone and soft tissue conditions are important for successful implant treatment. But, the placement itself is also very important. Implants which is installed in the wrong position result in the biological, esthetical and mechanical problems. In order to place an implant in the correct position, the final restoration and diagnostic wax-up should be considered prior to the surgery. If the artificial teeth for the interim denture are directly transferred from the diagnostic wax-up, the operator can try the form of diagnostic wax-up in the mouth. If the surgical template is produced by duplicating the interim denture, the implant can be placed in the planned position. In this case, the polymethyl methacrylate (PMMA) artificial tooth was precisely milled by the digital duplication of diagnostic wax-up. And interim denture was fabricated by using these milled teeth. After the patient adapted for a sufficient period, the implant was placed at the planned position with surgical template produced by duplicating the interim denture. After confirming sufficient osseointegration, the final prostheses were made to reflect the shape of diagnostic wax-up. Through this procedure, the satisfactory functional and esthetic outcome could be acquired.

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.4
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• pp.252-259
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• 2017

Purpose: The purpose of this study was to compare and analyze the wear of a prosthesis for 6 months after restoration with implant-supported fixed dental prosthesis made of either zirconia or gold. Materials and Methods: This study was conducted on patients requiring implant-supported fixed dental prostheses on first or second molar from January, 2015 to January, 2016. A total of 47 prostheses and antagonists were examined. Occlusal surface was recorded by impression of each prosthesis and antagonist 1 week and 6 months after prosthesis delivery. The digital files were created by impression scan. Occlusal shapes of 1 week and 6 months were compared and wear of prostheses and antagonists was analyzed. The Mann-Whitney test was used to analyzed the result data underwent normality test using SPSS (Version 23.0, IBM Corporation) Results: Mann-Whitney test revealed that there was no statistically significant difference in the median amount of mean vertical wear for 6 months in zirconia ($50.84{\mu}m$) and gold ($42.84{\mu}m$) prostheses (P > 0.05). When the opposing teeth were natural, the median amount of mean vertical wear of zirconia and gold prostheses was $47.72{\mu}m$ and $41.97{\mu}m$, respectively, and the median amount of mean vertical wear of enamel was $47.26{\mu}m$ and $44.59{\mu}m$, respectively. Statistical analysis showed no significant difference (P > 0.05). Conclusion: Despite the short study period and the small number of experimental groups, zirconia and gold showed no significant difference in wear during the first 6 months. Opposing natural enamel also showed no significant difference in the wear.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.2
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• pp.99-107
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• 2009

Statement of problem: Restoring and replacing teeth with fixed prostheses commonly used in dental practice. Because of improper oral hygiene care and inaccurate laboratory procedure, complications of fixed prostheses were found in the mouth of patients. Although many efforts have been continually made to obtain the data of long term prognosis of fixed prostheses, it was difficult to do it. Purpose: The purpose of this study was to evaluate the clinical status of fixed prostheses. Material and methods: In order to assess the clinical status of fixed prostheses, a total of 161 individuals(aged 17-85, 99 women and 62 men with 1596 unit of fixed prostheses, and 1169 abutments) who first visited the Department of Prosthodontics, Pusan National University Hospital, between April to September, in 2007 were examined. Results and conclusion: The results of this study were as follows: 1. Length of service of fixed prostheses was $8.6{\pm}0.6$ years(mean), 10.0 years(median). 2. Location of fixed prostheses was found to have no statistically significant influence on longevity of fixed prostheses(P>.05). But, the success rate was high in posterior region and in mandible where the failure rate was high in combination(P<.05). 3. Longevity of fixed prostheses made of metal was longest(mean: $13.0{\pm}9.3$, median: 14.0), gold, precious ceramic, non-precious ceramic trailing behind(P<.05). 4. Number of units in fixed prostheses was found to have no statistically significant influence on longevity of fixed prostheses(P>.05). But, the success rate was high in Single-unit and the failure rate was high in over 3-unit(P<.05). 5. Condition of opposing dentition was found to have no statistically significant influence on longevity of fixed prostheses(P>.05). But, the success rate was high in natural dentition(P<.05). 6. Defective margin(28.2%), dental caries(23.0%), periodontal disease(19.3%), periapical disease(16.9%) were frequent complications. In 30.1% of the cases, abutment state after removing fixed prostheses was needed to be extracted.