2-unit cantilever 레진접착성 가공의치 (resin-bonded fixed partial denture) 임상의 현재

이양진,조리라,박찬진,Yi Yang-Jin,Choi Lee-Ra,Parki Chan-Jin 대한치과보철학회 2003 대한치과보철학회지 Vol.41 No.1

Resin-bonded bridge has been an alternative to conventional bridge, since resin-bonded bridge has many attractive advantages such as minimal tooth preparation, short chair time and low cost over conventional bridge. Unfortunately, however, it was reported that resin-bonded bridge showed high failure rate from debonding of retainer in spite of consecutive advances in preparation and materials. And it was shown that multiple abutments were more likely to fail. The majority of debonding failure was considered due to the mobility of the abutment during function. In this view, recently, modification in resin-bonded bridge design was tried. Single retainer, single pontic. 2-unit cantilevered resin-bonded bridge was applied to clinical performance and was shown as retentive or more retentive than fixed-fixed type resin-bonded bridge. This was consistent with the results of studies in 2-unit cantilevered resin-bonded bridges made with all ceramic, In-ceram. The purpose of this article was to overview principles of design and to analyze clinical results of 2-unit cantilevered resin-bonded bridge in comparison with the reports of fixed-fixed resin-bonded bridge.

치밀골 두께 변화에 따른 임플랜트 1차안정성과 즉시하중부담능 평가

이양진,박찬진,조리라,Yi Yang-Jin,Park Chan-Jin,Cho Lee-Ra 대한치과보철학회 2005 대한치과보철학회지 Vol.43 No.2

Statement of problem. Cortical bone plays an important role in the primary implant stability, which is essential to immediate/early loading. However, immediate load-bearing capacity and primary implant stability according to the change of the cortical bone thickness have not been reported. Purpose. The objectives of this study were (1) to measure the immediate load-bearing capacity of implant and primary implant stability according to the change of cortical bone thickness, and (2) to evaluate the correlation between them. Material and methods.48, screw-shaped implants (3.75 mm$\times$7 mm) were placed into bovine rib bone blocks with different upper cortical bone thickness (0-2.5 mm) and resonance frequency (RF) values were measured subsequently. After fastening of healing abutment. implants were subjected to a compressive load until tolerated micromotion threshold known for the osseointegration and load values at threshold were recorded. Thereafter, RF measurement after loading, CT taking and image analysis were performed serially to evaluate the cortical bone quality and quantity. Immediate load-bearing capacity and RF values were analyzed statistically with ANOVA and post-hoc method at 95% confidence level (P<0.05). Regression analysis and correlation test were also performed. Results. Existence and increase of cortical bone thickness increased the immediate load-bearing capacity and RF value (P<0.05) With the result of regression analysis, all parameter's of cortical bone thickness to immediate load-bearing capacity and resonance frequency showed significant positive values (P<0.0001). A significant high correlation was observed between the cortical bone thickness and immediate load-beating capacity (r=0.706, P<0.0001), between the cortical bone thickness and resonance frequency (r=0.753, P<0.0001) and between the immediate load-bearing capacity and resonance frequency (r=0.755, P<0.0001). Conclusion. In summary, cortical bone thickness change affected the immediate load-baring capacity and the RF value. Although RF analysis (RFA) is based on the measurement of implant/bone interfacial stiffness, when the implant is inserted stably, RFA is also considered to reflect implant/bone interfacial strength of immediately after placement from high correlation with the immediate load-baring capacity. RFA and measuring the cortical bone thickness with X-ray before and during surgery could be an effective diagnosis tool for the success of immediate loading of implant.

하악 임플란트 Bicortication 의 응력분산효과에 관한 유한요소분석적 연구

이양진,양재호,이선형,정헌영,Yi, Yang-Jin,Yang, Jae-Ho,Lee, Sun-Hyung,Chung, Hun-Young 대한치과보철학회 1995 대한치과보철학회지 Vol.33 No.3

Dental implantation is a method restoring missing teeth, especially in the case of severely resorbed edentulous patient. But the direct contact between bone and implant surface, induces stress concentration to the bone and eventually becomes a cause. The purpose of this study was to compare the stress distribution patterns between following two cylindrical implant models. One group has implant apex located in the inferior cortical bone and the other in the cancellous bone. Anterior edentulous mandible was modeled with two dimensional 953,878 nodes, 995,918 elements and compared the deflection and stress distribution under the 70 N,4 load cases for 26 models having variant mandibular height and length. The result were as follows; 1. The stress concentration was more affected by the height of the mandible than implant length. 2. Bicortication mitigates the stress of upper cortical and cancellous bone area at the same height of the mandible 3. Perforation of the inferior mandibular cortex significant stress concentration. 4. Stud type porstheses induced less stress concentration to the cortical and cancellous bone than bar type prostheses. 5. Stress of implant apex for stud type was larger than that of bar type.

잇솔질과 열처리가 세로머의 색안정성에 미치는 영향

이양진,조리라,Yi Yang-Jin,Cho Lee-Ra 대한치과보철학회 2001 대한치과보철학회지 Vol.39 No.1

Ceromers, new indirect resin system, are now being adopted for esthetic restorations. Despite of its translucency and good color matching, color stability after long-term use was unknown till now. This in vitro study was designed to evaluate color stability of some ceromers when subjected to brushing after thermocycling. Three types of ceromers: Scupture, Targis, Artglass and a direct resin system, Z100 were prepared to disks 12 mm in diameter, 2.5 mm in thickness. All specimens were polished, and Sculpture and Targis specimens were divided two groups, respectively. Then, half of them were glazed according to manufacturer's instructions. All specimen were brushed 20,000 times after 10,000 cycle thermocycling. Color was measured with spectrophotometer after 1,000, 3,000, 10,000 times thermocycling and 20,000 time brushing, respectively. Color difference (${\Delta}E$) was calculated according to CIE LAB system. During thermocycling, Sculpture & Targis system with polished surface showed greater color change than any other groups. After brushing, color difference was reduced significantly. Mean values of ${\Delta}E$ ranged 0.98 to 2.98. All Ceromers were considered clinically acceptable after thermocycling and brushing, and color change mechanism was affected by the brands and finishing methods. It might be concluded that color change of ceromer is due to surface alteration.

반복하중하에서의 carbon fiber post의 파절강도에 관한 연구

이양진,Yi, Yang-Jin 대한치과보철학회 2000 대한치과보철학회지 Vol.38 No.5

In the restoration of endodontically treated teeth, carbon fiber post was recently introduced. The purpose of this in vitro study was to investigate the fracture strength of teeth restored with a pre-fabricated carbon fiber post in comparison with teeth restored with a prefabricated titanium post & custom cast gold post after cyclic loading in the different environment. A total of 30 recently extracted human central incisors of similar dimension with crowns removed were used. All teeth were placed into acrylic blocks and every steps for post and core fabrication were made accord-ing to manufacture's instruction. The post length and core dimensions were standardizd. All teeth were divided into 6 groups: 1) carbon fiber post / atmosphere, 2) titanium post / atmosphere, 3) gold post / atmosphere, 4) carbon fiber post / wet, 5) titanium post / wet, 6) gold post / wet. Carbon fiber post and titanium post were cemented in place using resin cement and cores were fabricated with Ti-Core. Custom cast gold post was made from Duralay pattern resin and cemented using resin cement, too. All specimens were thermocycled 10,000 times. After 50,000 cyclic loading, failure strength was measured using Instron testing machine. Kruskal-Wallis test followed by Mann-Whitney test was used to compare the mean fracture strength. Results were as follows : 1. All specimens showed lower fracture strength in wet environment after cyclic loading than in atmosphere condition, but did not reveal a significant difference. 2. There was no significant difference between carbon fiber post specimen and titanium post specimen in the same environment. 3. Gold cast post specimen showed significant different greater fracture strength than those of others in the same environment. 4. Carbon fiber post specimen showed no root fracture.

Y-TZP zirconia의 기계적 표면처리가 파절저항과 접착계면 실패에 미치는 영향

이양진(Yang-Jin Yi) 대한턱관절교합학회 2014 구강회복응용과학지 Vol.30 No.2

표면처리 장석포세린의 음향방출법을 이용한 파절하중 비교

이양진(Yang-Jin Yi),조리라(Lee-Ra Cho),박찬진(Chan-Jin Park) 대한치과재료학회 2007 대한치과재료학회지 Vol.34 No.2

최소침습수복의 전통과 전망

이양진(Yang Jin Yi) 대한치과의사협회 2011 대한치과의사협회지 Vol.49 No.2

In the filed of Dentistry, minimally invasive treatment modalities are new trend for conservation of natural teeth. Of them, laminate veneer and resin bonded fixed partial denture belong to restoration procedures. In this review, survival rates of each modalities and cause of unserviceability are analyzed, and criteria for success are presented. To get successful results of minimally invasive restoration, plenty of enamel layer, thin and strong materials, and high bonding strength are essential under cyclically loaded wet oral condition. Newly tried design of minimally invasive technique nowadays have to be evaluated only on the basis of requirement for long-term success.

Neutral Zone 개념과 Stereographic Record를 이용한 총의치 제작

이정민,이양진,조리라,Lee, Joung-Min,Yi, Yang-Jin,Cho, Lee-Ra 대한턱관절교합학회 2001 구강회복응용과학지 Vol.19 No.2

The success of complete denture prosthesis is to satisfy three basic requirements for the edentulous patient : maximum comfort, efficiency, and esthetic appearance. This can be achieved only if the dentures are both stable and retentive. When the residual alveolar ridge has resorbed significantly, stability and retention are more dependent on the correct position of the teeth and external surfaces of the denture. The stability and retention of the denture can be improved by locating the denture in the neutral zone and reproducing exact mandibular border movement for balanced occlusion. The neutral zone philosophy is based upon the concept that there exists a specific area where the musculature function will not unseat the denture in the mouth. In here, forces generated by the tongue are neutralized by the forces generated by the lips and cheeks. One of the simplest methods for recording border movements in three dimensions is to make stereographic record of condylar movement. Stereographs are made in the mouth during mandibular movement with intraoral clutches and central bearing point, and used in dictating the condylar movement on the articulator later by generating the condylar paths in doughy acrylic resin. Its procedure is simpler and more convenient than that of Pantograph. In this clinical report, we introduce the concept of neutral zone and stereograph in complete denture fabrication.

불안정한 하악운동을 보이는 환자에서 가철성 의치 수복 증례

손동환,이양진,조득원,Sohn, Dong-Hwan,Yi, Yang-Jin,Jo, Deuk-Won 대한치과보철학회 2020 대한치과보철학회지 Vol.58 No.1

구치부 지지소실과 편측 저작으로 교합이 환자는 불안정한 하악운동을 보이며, 이는 고령의 환자에서 복잡하게 나타날 수 있다. 본 증례에서는 교합붕괴와 이상 하악운동(Oral dyskinesia)을 보이는 환자에서 고딕아치 묘기법(Gothic arch tracing)과 스플릿 캐스트법(Split cast technique)을 이용하여 중심위와 습관적 전방 폐구위를 확인하고자 하였다. 이후 교합안정장치 형태의 임시의치를 사용하여 안정된 교합과 재현성 있는 하악운동을 회복하고자 하였고, 설측교합(Lingualized occlusion) 개념을 이용하여 총의치와 국소의치를 제작해 수복하였다. Patients with collapsed occlusal support and unilateral chewing show parafunctional mandibular movements, which can be complicated in older patients. Gothic arch tracing and split cast technique are used to confirm the deviation between centric relation and anterior habitual bite in patient who has oral dyskinesia and collapsed occlusion. Temporary denture as occlusal stabilization appliance was provided for stable occlusion and reproducible mandibular movement. Definitive denture was fabricated by lingualized occlusion concept.