• 대한치과보철학회:학술대회논문집
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• 2002.11a
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• pp.92-92
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• 2002

• 대한치과보철학회:학술대회논문집
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• 2001.11a
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• pp.66-66
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• 2001

• 대한치과보철학회:학술대회논문집
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• 2001.04a
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• pp.54-54
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• 2001

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.6
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• pp.529-536
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• 2010

Purpose: The Purpose of this study is to show the total survival rate of implants with maxillary sinus grafting and the effects that reach the survival rate by classifying types of graft materials, implant type, operation method, residual bone height and evaluate graft material resorption rate after sinus grafting Patients and Methods: 61 dental implants placed with sinus bone grafting in 24 patients at Wonkwang University Sanbon Dental Hospital were installed simultaneously or after regular healing. Various bone grafts (autograft, xenograft, allograft, alloplast) and fourth implant type (GSII, Xive, Implantium, Novel biocare) were used. All implants were investigated clinically and radiographically, being with average 20 months follow-up period after installation. Results: 3 fixtures were lost, resulting in 95.1% cumulative survival rate of 61 osseointegrated dental implant. Survival rate according to bone material type, Implant type, operation method, residual bone height, have no statistically significant differencies. The mean preoperative residual alveolar bone height was 4.75 mm, average postoperative height of graft materials 10.8 mm, vertical bone resorption rate was 10% after 2 years. Resorption rate according to operation method was 7% (simultaneous) and 5% (delayed) after 1 year. Conclusion: It can be suggested that maxillary sinus grafting may have predictable result with various bone graft materials and implant type, residual bone height, operation method

• The Journal of Korean Academy of Prosthodontics
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• v.29 no.1
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• pp.167-213
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• 1991

The successful replacement of missing teeth has been one driving aim behind the emergence of implant dentistry as both a technology and clinical vocation for over four decades. To date, a multitude of dental implant devices had been designed and utilized in the patient population. Most of these devices have been designed without support of the engineering criteria. The long-term success of any dental implant is dependent upon the optimization of stresses which occurs during oral function and parafunction. Although many studies have examined the biologic interactions between dental implants and living tissue, few studies have been reported on the biomechanical aspects of dental implants. The purpose of this study was to analyze the stress distribution of osseointegrated prosthesis on certain conditions, such as amount of load, location of load, length of fixtures, number of fixtures used, arch shape, bone quality, etc. Three dimentional finite element analysis was used for this study. FEM models were created using commercial software(Super SAP. for IBM 16 bit AT computer. All elements were 8-node brick, isoparametric. Mandible and prosthesis was modeled with 780 elements and 1074 nodes. The results were as follows : 1. In case of cantilever extension, there was a compressive stress at the base of the first implant and a tensile stress at the base of the second implant. 2. The stresses were linearly proportional to the amount of load. 3. The stresses were linearly proportional to the length of cantilever. 4. There was a stress concentration at the neck of the implant and bone under horizontal loads.

• The Journal of Korean Academy of Prosthodontics
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• v.31 no.4
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• pp.679-686
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• 1993

The osseointegrated implant conducts the stress directly to the bone due to lack of cushoning effect of periodontal ligament. So, the design and material quality of superstructure plays an important role in resolution and diffusion of stress. Recently, the various superstructures have been developed to improve esthetics and resolve various complicated conditions. The purpose of this study was to evaluate the stress induced by various system on the osseointegrated implant using UCLA abutment, EsthetiCone abutment, Anatomic abutment as well as Branemark conventional abutment. The stress distribution was evaluated by the photoelastic method which can simultaneously observe all around stress distribution. The superstructures embedded in epoxy resin specimen were loaded at various angle with a force of 15Kg to analyse the stress distribution of the fixture. The results of this study were obtained as follows : 1. Under vertical loading, the large and broad stress was distributed below the fixture in all systems. 2. The fringe order of the stress was increased in proportion to tillting the specimen. The largest stress was shown in 25 angled degree tilting case. 3. The Branemark conventional abutment showed the lowest value, and EsthetiCone abutment, Anatomic abutment and UCLA abutment showed the stress value in accending order.

• The Journal of Korean Academy of Prosthodontics
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• v.36 no.6
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• pp.806-815
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• 1998

Regular radiographic examination has been considered as an essential diagnostic method for the osseointegrated dental implantation. This study investigated the marginal bone loss through the measurement on the periapical radiograph around 46 endosseous dental implants. Marginal bone loss have been observed for 5 years after delivery of prostheses. The results were as follows : 1. According to the experimental periods, average marginal bone loss in total implant was 1.821mm in the first year, 1.833mm in the second, 1.892mm at third, 1.910mm at forth and 1.957mm at fifth after delivery of prostheses(P<0.05). 2. The average bone loss was 1.832mm in the maxillae and 1.819mm in the mandible in three years but there was no significant difference between the upper and lower jaw(P>0.05). 3. The average bone loss was 1.824mm in males and 1.818mm in females in five years but there was no significant difference according to the sex(P>0.05). These results indicate that the most of the alveolar bone loss occur within the first year after delivery of dental prostheses resulting in the exposure of polished neck positions, and the bone level stabilizes at first thread portion of the implant fixtures.

• The Journal of Korean Academy of Prosthodontics
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• v.39 no.6
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• pp.698-708
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• 2001

This study was to evaluate the clinical evidence for the success and the predictability of the osseointegrated dental implants in the partially edentulous Korean patients. 201 patients have received total of 502 Branemark implants, which were restored with either single or multiunit fixed superstructures at the Implants Clinic, Yonsei University Dental Hospital. The clinical and radiographic evaluations carried out on the patients for maximum 8 years were assessed annually for peri-implant inflammation, implant mobility (PTV), Plaque Index (PI), Gingival Index (GI), Bleeding on Probing (BOP), Keratinized Mucosa width and any changes in the surrounding bone level. The radiographs were taken at completion of the restoration, and annually thereafter. On the last recall appointments the patients filled a questionnaire consist of 29 questions in four categories. The cumulative non-failure rate of success was 93.9%. The first year mean bone loss was 0.3mm and less than 0.2mm annually thereafter. The periodontal parameters, keratinized tissue width and periotest values stabilized after initial changes in the first few years. The questionnaire has shown general satisfactory responses in all four aspect of dental implants treatment, including chewing efficacy, comfort, aesthetics and speech. The results support the predictability and success of the long-term rehabilitation of implant supported prostheses in partially edentulous Korean patients.

• The Journal of Korean Academy of Prosthodontics
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• v.31 no.1
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• pp.87-99
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• 1993

Many studies have been reported on the successful replacement of missing teeth with osseointegrated dental Implants. However, little research has been carried out on the bio-mechanical aspect of the stress on the surrounding bone of the free-standing type of dental implant prostheses. This experimental study was aimed to analyze the stress distribution pattern on the supporting tissues depending upon the position of osseointegrated implants supporting fixed bridges. In the cases of unilateral partially edentulous mandible (the 2nd premolar and the 1st and 2nd molars missing), two osseointegrated implants were placed at the 2nd premolar and 2nd molar sites (Model A) , the 1st and 2nd molar sites (Model B, Anterior cantilevered type), the 2nd premolar and 1st molar sites (Model C, Posterior cantilevered type). Chewing forces of dentate patients and denture wearer were applied vertically on the 2nd premolar, the 1st molar, and the 2nd molar of each model. A 3-Unit fixed partial denture was constructed at each model and cantilevered extension parts were involved in Model B and Model C. Two dimensional finite element analysis was undertaken. The commercial software (Super SAP) for IBM 16 bit personal computer was utilized. The results were as follows : 1. The magnitude of applied load influenced on the total value of stresses, but did not in-fluence on the pattern of stress distribution. 2. The magnitude of stress developed from the supporting tissues were in order of Model C,Model A,Model B. 3. High stresses were concentrated on the cervical and apical portion of the implant/bone interface. 4. A difference of the stress magnitude on the implant/bone interface between mesial and distal implant was most prominant in Model C and in order of Model A and Model B. 5. The stresses developed in Model A were evenly distributed throughout both implants. 6. The stresses concentrated on the cervical portion of cantilevered side were higher in the posterior cantilevered type than in the anterior cantilevered type.

• The Journal of Korean Academy of Prosthodontics
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• v.32 no.3
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• pp.445-454
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• 1994

Osseointegrated implant prostheses are to provide normal function without compromising the unique interaction between the tissue and the implant. The essential requirement for the osseointegrated implant prostheses is passive fit of abutment. Therefore, the impression must be accurate and reproduciable since the resultant master cast precisely duplicates the clinical condition. The purpose of this study was to compare the accuracy of the master casts obtained from five impression techniques. Group 1 : To take impression with indirect technique and Impregum F. Group 2 : To take impression with unsplinted direct technique and Impregum F. Group 3 : To take impression with splinted direct technique and Impregum F. Group 4 : To take impression with unsplinted direct technique and Xanthano. Group 5 : To take impression with splinted dierct technique and Xanthano. The results were as follow : 1. In taking impression of Impregum F, there was no significant difference between to use of indirect technique and unsplinted direct technique.(p<0.05) 2. Unsplinted direct technique with Impregum F is less accurate than splinted direct technique with Impregum F or Xanthano and unsplinted direct technique with Xanthano.(p<0.05). 3. There was no significant difference between splinted direct technique with Impregum F and unsplinted direct technique with Xanthano.(p<0.05) 4. Splinted direct technique reproduce more accurate than unsplinted direct technique.(p<0.05) 5. Impression plaster produced less distortion than polyether.(p<0.05) As a result, splinted direct technique with Xanthano was the most accurate technique. As a result, splinted direct technique with Xanthano was the most accurate technique in this study. In addition to dimensinal changes in the materials used, positional errors were also attributed to the mechanical components used in the transfer porocess. Although the errors measured were relatively small, this study demonstrates the potential for distortions with the transfer technique used. Further study is indicated that ?the technique will be able to reproduce the intraoral relationship of implant fixtures reliably and predictably.