• 대한치과의사협회지
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• 제55권8호
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• pp.528-536
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• 2017

Treatment with removable partial denture is effective for partially edentulous patients who are unable to obtain sufficient retention and stability for functional and esthetic restoration. There are several cases reporting the improvement of retention and stability of the partial denture using a small number of implants. However, there are limited studies on the implant-assisted removable partial denture using a small number of remaining teeth and the bar locator system. The bar locator system has an advantage in that it could compensate the angle of insertion of removable prosthesis on implant with inconsistent placement angle due to anatomical constraints compared to when using the locator only. This case report describes the patient with $Parkinson^{\circ}$Øs disease who was treated with the Locator bar system using two previously placed implants and two remaining teeth on maxilla. No additional implants could be placed because of the medical and economic condition of the patients, and the angle of one of two implants could not be matched with the direction of the removable partial denture insertion. Considering the angle of the implants, the patient was treated with implant-assisted RPD using the Locator bar system and had satisfactory results in the aspect of esthetics, masticatory function, and oral hygiene maintenance.

• 대한치과보철학회지
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• 제44권4호
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• pp.421-431
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• 2006

Statement of problem : Accurate impression is essential to success of implant prostheses. But there have been few studies about the accuracy of fixture-level impression technique in internal connection implant system. Purpose: This study evaluated the accuracy of splinted fixture-level impression technique using clinical methods and the effect of internal hex on fit of superstructure in internal connection implant system (Astra Tech). Material and method : Two metal master frameworks made from two abutments (Cast-to Abutment ST) each for parallel and divergent conditions and a corresponding. passively fitting, dental stone master cast with four future replicas (Fixture Replica ST) were fabricated. Ten dental stone casts were made with vinyl polysiloxane impressions from the master cast by acrylic resin splinted fixture-level impression technique. To evaluate the accuracy of impression technique, the fit of master frameworks for test models was evaluated using screw resistance test (SRT) and one-screw test. The results of SRT were recorded as SRT values from grade 1 to grade 5 by 1/4 turn. And to evaluate the effect of hex on fit of superstructure, the same tests were performed after removing hexes of master frameworks. Results: 1. There was only one case (2.5%) showing SRT value of test model below ade 2 in total before and after removing hexes of master frameworks. And, by removing hexes. SRT values decreased in only one test model (5%) and did not change in 17 test models (85%). 2. SRT values of the 1$^{st}$ screws were grade 2 in 80% of cases before, and grade 1 in 80% of cases after removing hexes. And, by removing hexes, SRT values decreased in 72.5% of cases. 3. SRT values of the 2$^{nd}$ screws were grade 3 in 85% of cases before, and grade 3 in 95% of cases after removing hexes. And, by removing hexes, SRT values did not change in 85% of cases. 4. There were only 2 cases regarded as acceptable fit by one-screw test, and SRT values of 2$^{nd}$ screws of both cases were grade 2. Conclusion. Within the limitations of this study, future-level impression of internal connection implant system is considered to obtain inaccurate working cast, even using acrylic resin splinted impression technique. And, it is considered to be unable improve the fit to remove the hexes of implant restoration.

• 대한치과보철학회지
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• 제60권2호
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• pp.168-174
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• 2022

상악 전치부의 임플란트 식립 시 치은 퇴축이나 골 결손 문제를 동반하는 경우에는 심미적인 임상 결과를 얻기가 쉽지 않다. 본 증례에서는 상악 우측 중절치에서 순측 치조골판의 소실이 진단되어 발치 후 연조직을 확보한 후에 골 이식을 동반하는 임플란트 식립을 계획하였다. 또한 이상적인 임플란트 식립 위치를 위해 디지털 가이드 수술을 시행하였고, 치조골 결손부가 광범위하기 때문에 하악지에서 자가골 채취 후 이종골과 함께 골유도재생술을 동반하였다. 충분한 임플란트의 골 유착 기간을 거친 뒤 2차 수술 및 인상 채득을 통한 임시 보철물을 제작하였고, 주기적인 외형 조정을 통해 연조직의 형태를 개선하였다. 최종 보철물 제작시에는 양극 처리를 시행한 맞춤형 지대주를 사용하여 자연 치아의 색조를 유도하였고, 구강 스캔을 통하여 임시 보철물의 형태를 재현해 줌으로써 심미적이고 기능적인 지르코니아 보철물을 장착해 주었다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제41권
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• pp.33.1-33.7
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• 2019

Background: The concept of the ideal morphology for the alveolar bone form is an important element to reconstruct or restore the in maximizing esthetic profile and functional alveolar bone restoration. The purpose of this preliminary study is to evaluate the normal alveolar bone structure to provide the standard reference and guide template for use in diagnosing for implant placement, determining the correct amount of bone augmentation in actual clinical practice and producing prostheses based on three-dimensional imaging assessment of alveolar bone. Methods: This study was included 11 men and 11 women (average age, 22.6 and 24.5 years, respectively) selected from among 127 patients. The horizontal widths of alveolar bone of maxilla and mandible were measured at the crestal, mid-root, and root apex level on MDCT (multi-detector computed tomography) images reconstructed by medical imaging software. In addition, tooth dimensions of the central incisors, canines, second premolars, and first molars of maxilla and mandible, including the horizontal width of the interdental alveolar bone crest, were also measured and statistically analyzed. Results: The horizontal alveolar bone width of the palatal side of maxilla showed a distinct increment from the alveolar bone crest to the apical region in both anterior and posterior areas. The average widths of the maxillary alveolar ridge were as follows: central incisor, 7.43 mm; canine, 8.91 mm; second premolar, 9.57 mm; and first molar, 12.38 mm. The average widths of the mandibular alveolar ridge were as follows: central incisor, 6.21 mm; canine, 8.55 mm; second premolar, 8.45 mm; and first molar, 10.02 mm. In the buccal side, the alveolar bone width was not increased from the crest to the apical region. The horizontal alveolar bone width of an apical and mandibular border region was thinner than at the mid-root level. Conclusions: The results of the preliminary study are useful as a clinical guideline when determining dental implant diameter and position. And also, these measurements can also be useful during the production of prefabricated membranes and customized alveolar bone scaffolds.

• 대한치과보철학회지
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• 제60권4호
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• pp.362-373
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• 2022

완전 무치악 환자의 고정성 보철 수복 시 수술 전 적합한 치아 위치를 확인하고 잔존 치조골과 연조직의 평가를 통해 수술을 계획하여 정확한 임플란트를 식립하는 것이 필수적이다. 가이드 임플란트 수술과 CAD-CAM 기술은 보철 치료와 수술을 동시에 계획할 수 있고 치료에 대한 예지력을 확보할 수 있는 장점이 있다. 본 임상 증례에서는 이러한 디지털 기술을 활용하여 임시의치 제작, 고정성 수복 치료 전 심미성 평가 및 가이드 수술을 계획하였다. 수술 후에도 기존에 얻었던 정보들을 통해 고정성 임시 보철물을 제작하는데 유용하게 사용되었으며 최종적으로 임시 보철물을 반영하여 단일 구조 지르코니아 보철물을 제작하였고 기능적, 심미적으로 만족스러운 결과를 얻었기에 이를 보고하고자 한다.

• 대한치과보철학회지
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• 제61권4호
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• pp.316-327
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• 2023

구치부 심한 골소실을 보이는 완전 무치악 환자에게 이공 전방에 4개 이상의 임플란트를 식립 후 전악 수복을 하는 'All-on-X' 임플란트 지지 고정성 보철 수복을 고려해 볼 수 있다. 과거에는 이러한 임플란트 고정성 보철 수복시 특별한 기준점 없이 술자의 판단에 의존하여 잔존 치조제에 임플란트를 식립하고 보철 수복 단계에선 이미 식립된 임플란트에 맞춰서 보철물을 제작하는 방식이었지만, 최근 디지털 치의학의 발전으로 진단, 수술, 보철 제작 등 모든 과정에서 계획적이고 예지력 있는 치료가 가능해졌다. 디지털 총의치, 임플란트 서지컬 가이드, 안면스캔 그리고 복제 의치를 통한 인상 채득 등의 디지털 기술들을 사용하여 복잡한 기공 과정을 줄이고, 임시 수복물의 심미와 기능을 최종 보철물로 효과적으로 이행할 수 있다. 상기 환자는 상악 디지털, 하악 'all-on-x' 임플란트 고정성 보철물 수복환자로, 진단부터 최종 수복까지 디지털 기술을 활용하여 기능과 심미성을 만족시키는 보철물을 제작할 수 있었기에 이를 보고하고자 한다.

• 구강회복응용과학지
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• 제40권2호
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• pp.64-71
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• 2024

목적: 본 연구의 목적은 세 가지 높이를 가진 티타늄 베이스 임플란트 지대주에서 세 종류의 시멘트가 지르코니아 수복물에서 가지는 제거력을 비교하는 것이다. 연구 재료 및 방법:. 90개의 직경 4.0 mm 임플란트 아날로그가 레진 블록에 식립되었다. 이후 3 mm, 5 mm, 7 mm의 높이를 가지도록 임플란트 지대주를 30개씩 제작하였고, 각 지대주를 스캔하여 지르코니아 수복물 시편을 제작하였다. 임시 시멘트(TB), 반영구 시멘트(CI), 영구 시멘트(FC)를 각자 제조사의 지시에 따라 지대주에 접착하였다. 제작된 90개의 시편은 만능시험기에서 제거력을 시험하였으며, 모든 제거력은 부하량이 하락하기 직전 가장 높은 값에서 측정되었다. 통계 분석은 지대주의 높이, 시멘트의 종류에 대해 각각 Kruskal-Wallis test (P = 0.05) 후 Mann-Whitney U test (P = 0.0167)로 사후 검정 시행하였다. 결과: 임플란트 지대주의 높이에 상관없이 TB에 비해 FC의 제거력이 높았다. CI와 FC간에는 3 mm와 7 mm에서는 유의미한 차이가 있었으나 5 mm에서는 유의미한 차이가 없었다. TB와 CI간에는 5 mm에서만 유의미한 차이가 있었다. 결론: 시멘트의 종류는 지르코니아 수복물의 제거력에 유의미한 영향을 끼쳤으나, 임플란트 지대주의 높이는 유의미한 영향을 주지 않았다.

• Journal of Periodontal and Implant Science
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• 제25권1호
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• pp.111-120
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• 1995

This case report presents two maxillary anterior cases for clinical crown lengthening by forced eruption. In the first case, clinical crown of maxillary right lateral incisor was almost lost by fracture. Forced eruption using intracoronal splint and elastic thread accomplished vertical root movement successfully. Then, post & core was inserted and final restoration was harmonious with adjacent teeth. In the second case, the crown portion of maxillary right central incisor was almost mutilated by secondary caries. Forced eruption using removable Hawley appliance and elastic accomplished vertical root movement successfully. Then, post & core was inserted and final restoration was placed. In conclusion, clinical crown lengthening by vertical root movement can be accomplished by a simple appliance without any sacrifice of periodontal support in selected patients. A clinical crown so created can be restored to adequate function and arch integrity without compromising adjacent teeth. Therefore, forced eruption is preferred in the anterior region of the dentition where esthetics is of major concern.

• 구강회복응용과학지
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• 제22권4호
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• pp.301-307
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• 2006

The subgingival fracture near the alveolar bone is difficult to treat. This fractured tooth will be treated by many methods. First approach is to preserve the fractured tooth. Periodontal surgery has been used to lengthen the clinical crown, thereby allowing the tooth to be restored. Another method is erupting the tooth with orthodontic eruption (forced eruption) or surgical extrusion. Second approach is the restoration after extraction of the subgingivally fractured tooth. This is restorative with conventional fixed partial denture or implant. This article presents the variable restorative approach of subgingivally fractured upper incisor.

• The Korean Journal of Physiology and Pharmacology
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• 제13권3호
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• pp.221-227
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• 2009

For successful restoration of visual function by a visual neural prosthesis such as retinal implant, electrical stimulation should evoke neural responses so that the informat.ion on visual input is properly represented. A stimulation strategy, which means a method for generating stimulation waveforms based on visual input, should be developed for this purpose. We proposed to use the decoding of visual input from retinal ganglion cell (RGC) responses for the evaluation of stimulus encoding strategy. This is based on the assumption that reliable encoding of visual information in RGC responses is required to enable successful visual perception. The main purpose of this study was to determine the influence of inter-dependence among stimulated RGCs activities on decoding accuracy. Light intensity variations were decoded from multiunit RGC spike trains using an optimal linear filter. More accurate decoding was possible when different types of RGCs were used together as input. Decoding accuracy was enhanced with independently firing RGCs compared to synchronously firing RGCs. This implies that stimulation of independently-firing RGCs and RGCs of different types may be beneficial for visual function restoration by retinal prosthesis.