• The Journal of Korean Academy of Prosthodontics
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• v.44 no.4
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• pp.394-404
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• 2006

Statement of problem: A conventional 3-unit fixed partial denture design with a pontic between two retainers is the most commonly used. However in cases where the mental nerve is in close proximity to the second premolar, a cantilever design can be considered. As such, logical and scientific evidence is lacking for the number and position of implants to be placed for partially edentulous patients, and no clear-cut set of treatment principles currently exist. Purpose : The purpose of this study was to evaluate prognosis of implant-supported fixed partial dentures and to compare changes in bone level which may rise due to the different factors. Material and method : The present study examined radiographical marginal bone loss in patients treated with implant-supported fixed partial dentures (87 prostheses supported by 227 implants) and evaluated the influence of the span of the pontic, type of the opposing dentition. Clinical complications were studied using a retrospective method. Within the limitation of this study. the following result were drawn Result, 1. Seven of a total of 227 implants restored with fixed prostheses failed, resulting in a 96.9% success rate. 2. Complications encountered during recall appointments included dissolution of temporary luting agent (17 cases), porcelain fracture (8 cases), loosened screws (5 cases), gingival recession (4 cases), and gingival enlargement (1 case). 3. Marginal bone loss, 1 year after prosthesis placement, was significant(P<0.05) in the group that underwent bone grafting, however no difference in annual resorption rate was observed afterwards. 4. Marginal bono loss, 1 year post-placement, was greater in cantilever-type prostheses than in centric pontic protheses (P<0.05). 5. Marginal bone loss was more pronounced in posterior regions compared to anterior regions (P<0.05). 6. The degree of marginal bone loss was proportional to the length of the pontic (P<0.05). Conclusion: The success rate of implant-supported fixed partial dentures, including marginal bone loss, was satisfactory in the present study. Factors influencing marginal bone loss included whether bone graft was performed, location of the pontic (s), location of the surgical area in the arch pontic span. Long-term evaluation is necessary for implant-supported fixed partial dentures, as are further studies on the relationship between functional load and the number of implants to be placed.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.10 no.2
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• pp.21-30
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• 2001

Fiber reinforced materials have favorable mechanical properties. Moreover, the strength to weight ratios of this material is superior to those of most alloys. Comparing to the metals, it showed many other advantages as well, including non-corrosiveness, translucency and easy repair characteristic. Since, it has the potential for the chair-side and laboratory fabrication, it is not surprising that fiber reinforced composites offer the potential for use in various applications in dentistry. To make the well-fitted restorations, Fiber reinforced composite (FRC) has been suggested as an alternative framework material for the implant supported fixed prosthesis. Two fixed partial denture fabrication procedures were tried. Vectris fiber was pressed to the EsthetiCone gold cylinder on the implant positioned cast. And then, Targis were added on it. In the other method, we used the customized component using UCLA abutment. The beads for retaining the Vectris fiber were added on the abutment. If careful laboratory and clinical techniques were done, these two techniques would fulfill the demands of the esthetics and strength.

• The Journal of Korean Academy of Prosthodontics
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• v.51 no.3
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• pp.214-220
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• 2013

Implant prosthodontics is beneficial for edentulous patients in enhancing the support, retention, stability, phonation and so on. Various types of prosthesis supported by implant, including implant retained- or supported- overdenture for the removable type and ceramo-metal and fixed prostheses with processed acrylic teeth for the fixed type, are frequently used. Treatment planning for the prosthesis with implant must be made after considering individual characteristics such as form of residual ridge, soft tissue, interocclusal relationship, economic status. Fixed prosthesis with processed acrylic teeth (also known as 'implant hybrid prosthesis' or 'bone anchored bridge') has the advantages of both removable and fixed prosthesis such as proper soft tissue profile, esthetic outcome, increased masticatory efficiency and psychological stability. The 73-years-old female patient came to the department of prosthodontics, Dental hospital of Yonsei University. She was diagnosed with Kennedy class I partial edentulism in the maxilla and complete edentulism in the mandible. This article reports a satisfactory clinical and esthetic outcome of full mouth rehabilitation using removable partial denture in the maxilla and implant hybrid prosthesis in the mandible.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.4
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• pp.359-365
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• 2014

Successful results of treatments using double crown prostheses for the partially edentulous patients who have a few remaining teeth have been reported in several journals. A double crown removable partial denture can be an alternative treatment for the patients with a poor periodontal condition of remaining teeth. Since a double crown removable partial denture can be applied without the risk of surgical operation to the medically compromised patients with a poor periodontal condition which is inadequate for dental implants, it has psychological and economical advantages. In this case, there were sufficient remaining teeth to be restored with fixed prostheses in maxilla, while there were a few remaining teeth with a very poor periodontal condition so that it was almost impossible to restore with a clasp removable partial denture using these remaining teeth in mandible. In addition, the patient had the medical history of surgical operation due to osteomyelitis in the mandibular anterior areas a year ago, thus difficult to conduct an implant placement. The main objective of this report is to introduce our case because a double crown partial denture using a few mandibular remaining teeth showed satisfactory results in functional and esthetical aspects during more than two years follow-up period in this unfavorable condition.

• The Journal of Korean Academy of Prosthodontics
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• v.61 no.4
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• pp.367-378
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• 2023

With the recent development of computer-aided design-computer-aided manufacturing technology and 3D printing technology, and the introduction of various digital techniques, the accuracy and efficiency of top-down definitive prosthetic restoration are increasing. In this clinical case, stable occlusion support was obtained through the placement of a total of 9 maxillary and mandibular posterior implants in patient with anterior-posterior crossed occlusion. The edentulous area of the maxillary anterior teeth, which showed a tendency of high resorption of the residual alveolar bone, was restored with a Kennedy Class IV implant assisted removable partial denture to restore soft tissue esthetics. Computed tomography guided surgery was used to place implants in the planned position, double scan technique was used to reflect the stabilized occlusion in the interim restoration stage to the definitive prostheses, and metal 3D printing was used to manufacture the coping and framework. This clinical case reports that efficient and predictable top-down full mouth rehabilitation was achieved using various digital technologies and techniques.

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.4
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• pp.807-823
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• 1995

The purpose of this study was to analyze the stress distribution and the displacement happened to the abutment, the prosthesis, and the surrounding structure according to the location of the nonrigid connector, that is, the keyway in the distal of canine and the mesial of the implant in the three unit fixed partial denture. Two-dimensional finite element model ws constructed and analyzed for the stress distribution and the displacement using software ABAQUS(Ver 5.2 Hibbitt, Karisson & Sorenson, Inc., 1992). After finishing the finite element model, the distribution load of 15kg was applied simultaneously to the all cusp tips of the prosthesis and the concentration load of 10㎏ was applied respectively at the each cusp tip of the prosthesis. The following results were obtained : 1. The amount of displacement of the implant was greater in case of the non-rigid connection than the rigid connection, and the more favorable displacement was shown in case of the IKb than the IKa. 2. Without regard to the connection method, the stress represented at the surrounding bone was similar, and the more favorabel stress distribution was shown in case of IKb. 3. The maximum stress was concentrated at the fastening screw and the neck of implant in all experimental groups, and their stress magnitudes were in the order of IKb, IR, and IKa.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.2
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• pp.166-179
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• 2008

Excessive concentration of stress which is occurred in occlusion around the implant in case of the implant supported fixed partial denture has been known to be the main cause of the crestal bone destruction. Therefore, it is essential to evaluate the stress analysis on supporting tissue to get higher success rates of implant. The purpose of this study was to evaluate the effects of stress distribution and deformation in 3 different types of three-unit fixed partial denture sup-ported by two implants, using a three dimensional finite element analysis in a three dimensional model of a whole mandible. A mechanical model of an edentulous mandible was generated from 3D scan, assuming two implants were placed in the left premolars area. According to the position of pontic, the experiments groups were divided into three types. Type I had a pontic in the middle position between two implants, type II in the anterior posi-tion, and type III in the posterior position. A 100-N axial load was applied to sites such as the central fossa of anterior and posterior implant abutment, central fossa of pontic, the connector of pontic or the connector between two implants, the mandibular boundary conditions were modeled considering the real geometry of its four-masticatory muscular supporting system. The results obtained from this study were as follows; 1. The mandible deformed in a way that the condyles converged medially in all types under muscular actions. In comparison with types, the deformations in the type II and type III were greater by 2-2.5 times than in the type I regardless of the loading location. 2. The values of von Mises stresses in cortical and cancellous bone were relatively stable in all types, but slightly increased as the loading position was changed more posteriorly. 3. In comparison with type I, the values of von Mises stress in the implant increased by 73% in Type II and by 77% in Type III when the load was applied anterior and posterior respectively, but when the load was applied to the middle, the values were similar in all types. 4. When the load was applied to the centric fossa of pontic, the values of von Mises stress were nearly $30{\sim}35%$ higher in the type III than type I or II in the cortical and cancellous bone. Also, in the implant, the values of von Mises stress of the type II or III were $160{\sim}170%$ higher than in the type I. 5. When the load was applied to the centric fossa of implant abutment, the values of von Mises stress in the cortical and cancellous bone were relatively $20{\sim}25%$ higher in the type III than in the other types, but in the implant they were 40-45% higher in the type I or II than in the type III. According to the results of this study, musculature modeling is important to the finite element analysis for stress distribution and deformation as the muscular action causes stress concentration. And the type I model is the most stable from a view of biomechanics. Type II is also a clinically accept-able design when the implant is stiff sufficiently and mandibular deformation is considered. Considering the high values of von Mises stress in the cortical bone, type III is not thought as an useful design.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.26 no.1
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• pp.52-63
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• 2017

When you need to make an upper and lower full-mouth prosthesis, you should design a prosthesis by making an accurate diagnosis and planning well. In particular, in patients with occlusal plane collapsed and misplaced occlusal plane, the patient should be restored to the previous occlusal height and the correct occlusal plane should be created. In addition, appropriate materials should be used to ensure that the patient is able to chew the food well and not force it. When the implants are placed in an inappropriate position, the design of the prosthesis is determined by considering the relationship with the prosthesis and occlusion. Design should be made for the cleanliness around the implant.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.2
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• pp.201-209
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• 2021

In removable partial dentures, many types of retentive systems have been studied and applied in clinical treatment. One of those systems is the double crown denture system which is widely used in European countries such as Germany and Sweden. Telescopic double crown dentures have several advantages such as convenience in maintaining oral hygiene, enabling to transfer occlusal force along the long axis of the abutment, and secondary splinting effect between the abutments which leads to higher clinical performance compared to conventional removal partial dentures. In this clinical case, the patient was initially restored with a maxillary hybrid telescopic double crown denture with friction pin using remaining natural teeth as abutments. After 7 years, due to lack of recall check-up and poor oral hygiene, the abutment teeth were affected by periodontitis and 4 out of 5 of the abutment teeth had to be extracted. 3 additional implants were placed and the original abutment tooth with the inner crown was maintained. The mandible had fixed prostheses including implants but nevertheless, with strategic implant placement, the patient adapted well and was satisfied with the new maxillary tooth-implant combined double crown denture.

• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.4
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• pp.314-321
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• 2016

Conventional removable partial dentures (RPDs) with distal extensions are associated with some problems, including lack of stability that calls for frequent relining, and cantilever actions of claps that can produce excessive loading to abutment teeth, and the need for unesthetic retentive arm clasps. Therefore, IARPDs (Implant-assisted RPD) that use implants to support or retain RPDs has been reported to improve stability, esthetics and masticatory performance of RPDs. Also, an IARPD that has zirconia occlusal table can prevent the incongruity of occlusal plane and the extrusion of antagonistic tooth. In this case of partially edentulous patient with crossed occlusion, each edentulous area was restored with implant fixed prosthesis and implant retained partial denture to suit each situation. Through the procedure, satisfactory outcomes were achieved both in functional and esthetic aspects.