보철물 조건에 따른 Periotest수치의 실험적 평가

한중석,Han, Jung-Suk 대한치과보철학회 1997 대한치과보철학회지 Vol.35 No.4

Periotest(Siemens, Germany) has been used to test mobility of the implants clinically, however the effects of target materials and connection methods on the PTVs(Periotest Values) have not been evaluated. Periotest has been regarded as a reliable and objective tool to test implant and natural teeth mobility clinically, however this instrument showed different PTVs under various test conditions. This in vitro study was designed to compare PTVs of different veneering materials and prosthodontic designs (single and bridge restorations). To compare the effects of veneering materials on PTVs, 1 mm thickness of five different testing materials (porcelain, type III gold alloy, pure titanium, composite resin, acrylic resin) were placed on the resin block. Three full length of 13 mm Mark II implant fixtures were embedded into autopolymerizing resin block to fabricate single and bridge restorations. To evaluate effects of the connection method in single restorations, PTVs of screw retained(UCLA type) and cementation type(Cera-One system) were compared. Finally, to test reliability of PTVs of the final restorations, screw retained three unit short span PFM bridges were fabricated on the standard and Estheti-Cone abutments. All testing components were tightened with torque controller and PTVs of all specimens were measured 15 times for statistical analysis with SAS program. Following conclusions were made within the limit of this in vitro study. 1. PTVs of type III gold alloy, grade II titanium, composite resin veneering materials showed no significant differences, however acrylic resin and porcelain showed significant differences (P<0.05). 2. Single tooth restorations showed consistent PTVs as long as proper torque force was applied. 3. PTVs of bridge type prostheses was inconsistent regardless of abutment types. 4. PTVs of the prostheses showed higher scores and standard deviations than those of abutments regardless types of connection (P<0.05).

유기조성물을 이용한 페이스트형 일반도재 시스템

한중석(Jung-Suk Han),이명현(Myung-Hyun Lee),김대현(Dae-Hyun Kim),정헌영(Hun-Young Chung) 대한턱관절교합학회 2004 구강회복응용과학지 Vol.20 No.2

서울시 정비구역 해제에 따른 매몰비용의 공공부담에 관한 연구

한중석(Han, Jung-Seok),최민섭(Choi, Min-Seub) 한국주거환경학회 2015 주거환경(한국주거환경학회논문집) Vol.13 No.4

The purpose of this study is to suggest the reasonable legal principles in relation to public burden of sunk costs incurred in process of rearrangement projects for providing assistance in legislation or dispute resolution. This study attempted to analyze literature such as theses, articles in journals, the National Assembly bills and the review reports, the National Assembly records of proceedings, the Supreme Court precedents, the Constitutional Court decisions, press releases, and Seoul metropolitan survey data on cancellation of rearrangement zones and sunk costs. In addition, this study attempted to analyze the current status and system associated with cancellation of rearrangement zones and subsidy of sunk costs. And then it raised the legal issues such as the justification, object, subject, degree of public burden of sunk costs. The results of the study are as follows: First, the public burden of sunk costs incurred in process of rearrangement projects is justified since rearrangement projects have publicness. Second, sunk costs incurred in process of rearrangement projects by the association as well as by the promotion committee should be shared by public sector since there is no difference in substance between the two. Third, sunk costs incurred in process of rearrangement projects should be shared by national government as well as by local government since national government is directly or indirectly involved in rearrangement projects. Last, sunk costs incurred in process of rearrangement projects should be shared by public sector under the principle of publicness, profitability, and responsibility.

Air-Powder Abrasive System (공기-분말 마모기기)의 치아 마모에 관한 연구

한중석(Jung-Suk Han) 대한치과의사협회 1990 대한치과의사협회지 Vol.28 No.4

Computer guided implant surgery와 CAD/CAM을 활용한 전악 수복 증례

김성진,한중석,김성훈,윤형인,여인성,Kim, Sungjin,Han, Jung-Suk,Kim, Sung-Hun,Yoon, Hyung-In,Yeo, In-Sung Luke 대한치과보철학회 2019 대한치과보철학회지 Vol.57 No.1

Computer aided design and manufacturing and implant surgery using a guide template improve restoration-driven implant treatment procedures. This case utilized those digital technologies to make definitive prostheses for a patient. According to the work flow of digital dentistry, cone beam computed tomography established the treatment plan, which was followed to make the guide template for implant placement. The template guided the implants to be installed as planned. The customized abutments and surveyed fixed restorations were digitally designed and made. The metal framework of the removable partial denture was cast from resin pattern using an additive manufacturing technique, and the artificial resin teeth were replaced with the zirconia onlays for occlusal stability. These full mouth rehabilitation procedures provided functionally and aesthetically satisfactory results for the patient. Computer guided implant surgery와 computer-aided design/computer-aided manufacturing, computer guided implant surgery (CAD/CAM) 기술의 발전은 수복 기반 임플란트 치료의 완성도를 한층 더 높였으며, 3D printing을 통한 국소의치의 제작도 빈도가 늘고 있다. 본 증례는 디지털 치의학의 작업 흐름을 따라서 콘빔컴퓨터단층촬영을 통한 치료 계획 수립 및 수술용 스텐트의 제작과 그를 바탕으로 한 임플란트 식립을 하였으며, 맞춤 지대주와 보철물을 제작하였다. 그 후 전자 서베잉과 3D printing을 통한 국소의치 금속 구조물 및 최종적으로 지르코니아 온레이의 제작을 통해 전악 수복을 완성하여 기능과 심미적으로 만족스러운 결과를 얻을 수 있었다.

임플랜트 상부구조의 재료가 반복하중 후 나사풀림에 미치는 영향

이태식,한중석,양재호,이재봉,김성훈,Lee, Tae-Sik,Han, Jung-Suk,Yang, Jae-Ho,Lee, Jae-Bong,Kim, Sung-Hun 대한치과보철학회 2007 대한치과보철학회지 Vol.45 No.2

Statement of problem: A phenomenon of screw-loosening in implant abutment is frequently occurred in a single and multiple implant restoration. Purpose: This study was performed to evaluate an effect of abutment material on screw-loosening before and after a cyclic loading. In a single-tooth implant, different materials of abutment, Type III Gold alloy and Zirconium composite$(ZrO_2/Al_2O_3)$ were used. Material and method: The Gold alloy(Type III) and Zirconium composite$(ZrO_2/Al_2O_3)$ were used to make a superstructure of implant, the one of types of UCLA, Each group was constituted of 5 sample with a 30-degree offset angulated loading platform. The external hexagonal fixture was rigidly hel d in a special holding zig to ensure solid fixation without rotation during the tightening and a cyclic loading. A Titanium-alloy screw was used to connect and controlled to be tighten in 20Ncm torque by a digital torque gauge. A 20 times of consecutive closing/opening cycle were performed to evaluate the immediate torque loss. In 5 sample of each material group, an initial opening torque was recorded during 3 closing/opening cycle, then 2Hz, 200N, 1,000,000 cyclic loadings were performed, then a opening torque was evaluated. Result & Conclusion: 1. In this limited study, titanium alloy screw tightened in 20Ncm, a cold-welding phenomen on was not observed during the 20 times of closing/opening cycle(p=0.11, p=0.18). 2. In titanium alloy abutment screw, repeated opening and closing of the screw caused to progressive decrease of opening torque(p=0.014). 3. The difference in preload of screw between gold alloy abutment and ceramic$(ZrO_2/Al_2O_3)$ abutment was not significant(p=0.78). 4. The difference in torque loss of screw between gold alloy abutment and ceramic$(ZrO_2/Al_2O_3)$ abutment was not significant after 2Hz,200N, 1,000,000 cyclic loading(p=0.92). 5. In titanium alloy abutment screw tightened by 20Ncm, the screw loosening was not significant on each group after 2Hz, 200Ncm, 1,000,000 cyclic loading(p=0.59).

치아 마모 환자에서 단일 구조 지르코니아를 이용한 완전 구강 회복 증례

김태연,한중석,김성훈,여인성,이재봉,Kim, Tae-Yeon,Han, Jung-Suk,Kim, Sung-Hun,Yeo, In-Sung,Lee, Jai-Bong 대한치과보철학회 2016 대한치과보철학회지 Vol.54 No.2

심한 치아 마모는 치질의 손상, 교합면의 부조화, 기능적, 심미적 문제들을 야기할 수 있다. 치아의 마모로 인해 나타나는 수직 고경의 감소는 악골의 보상성 성장과 치아의 맹출로 어느 정도 상쇄될 수 있지만 심미적 보철물을 제작하는 데 필요한 공간과 보철물의 유지 등을 얻기 위해서는 수직 고경의 거상이 필요할 수 있다. 본 증례의 환자는 44세 남자 환자로 다수 치아에 마모를 가지고 있고 심미적인 치아를 원한다는 주소로 본원에 내원하였다. 수복을 위한 악간 공간이 부족하여 진단 왁스업을 토대로 전치부 기준 3 mm의 수직고경 거상을 결정하고, 가철성 교합 안정 장치와 임시수복물을 적정 기간 사용하여 환자의 적응도를 평가하였다. 적절한 적응을 확인한 후 단일 구조 지르코니아를 이용한 고정성 보철물로 전악 수복하였고 비기능적 습관으로부터 보철물과 주위 조직을 보호하기 위해 연질의 교합안정장치를 장착하게 하였다. 이상과 같은 치료 과정을 통해 수직 고경 거상을 동반한 보철 수복을 실시하였고 적절한 심미적, 기능적 결과를 얻었기에 이를 보고하고자 한다. Excessive occlusal wear causes loss of tooth structure, occlusal plane disharmony, impaired function and esthetic problems. Although the decrease of occlusal vertical dimension may be compensated by the growth of alveolar bone and tooth eruption, minimal increase of occlusal vertical dimension may be required for esthetics and retention of prosthesis. In this case, a 44-year-old male patient visited Seoul National University Dental Hospital with chief complaint of severe tooth wear and shade disharmony. Based on assessment of diagnostic wax-up, 3 mm increase of occlusal vertical dimension was determined. Removable occlusal splint and interim prosthesis was used to ascertain patient's comfort and adaptation. After the adaptation period, definitive prosthesis fabricated with full-contour monolithic zirconia were delivered and the patient was recommended to wear a nightguard device for prosthesis protection. This report presents a case of full mouth rehabilitation with the elevation of patient's occlusal vertical height, resulting in satisfactory esthetics and functions.

極値流量의 最適分布型과 極値確率 流量에 關한 水文學的 硏究 -錦江流域의 渴水量을 中心으로-

이순혁,한중석,Lee, Soon-Hyuk,Han, Chung-Suck 한국농공학회 1979 한국농공학회논문집 Vol.21 No.4

In order to obtain the basic data for design of water structures which can be contributed to the planning of water use. Best fitted distribution function and the equations for the probable minimum flow were derived to the annual minimum flow of five subwatersheds along Geum River basin. The result were analyzed and summarized as follows. 1. Type III extremal distribution was considered as a best fit one among some other distributions such as exponential and two parameter lognormal distribution by $x^2$-goodness of fit test. 2. The minimum flow are analyzed by Type III extremal distribution which contains a shape parameter $\lambda$, a location parameter ${\beta}$ and a minimum drought $\gamma$. If a minimum drought $\gamma=0$, equations for the probable minimum flow, $D_T$, were derived as $D_T={\beta}e^{\lambda}1^{y'}$, with two parameters and as $D_T=\gamma+(\^{\beta}-\gamma)e^{{\lambda}y'}$ with three parameters in case of a minimum drought ${\gamma}>0$ respectively. 3. Probable minimum flow following the return periods for each stations were also obtained by above mentioned equations. Frequency curves for each station are drawn in the text. 4. Mathematical equation with three parameters is more suitable one than that of two parameters if much difference exist between the maximum and the minimum value among observed data.

수종 임플랜트 지대주나사의 반복하중 후 나사풀림에 관한 연구

김진만,한중석,이선형,양재호,이재봉,김영수,Kim Jin-Man,Han Jung-Suk,Lee Sun-Hyung,Yang Jae-Ho,Lee Jae-Bong,Kim Yung-Soo 대한치과보철학회 2003 대한치과보철학회지 Vol.41 No.4

Statement of problem : Chronic implant screw loosening remains a problem in restorative practices. Some implant manufactureres have introduced abutment screws with treated material, surfaces and macrostructures in an effort to reduce potential loosening. Purpose : This study evaluated the materials and loading cycles on detorque value after dynamic continous fatigue test in the sinulated conditions of posterior single restoration. Material and method : Fourteen of each of the following abutment screws - titanium alloy, gold alloy, gold-tite, and titanium alloy modified - were used in test. SEM is used to verify macrostructures of each screws. $ZrO_2/Al_2O_3$ composite abutment was tightened on $4{\times}10.0mm$ titanium external implant at 30 Ncm. Cyclic loading machine delivered dynamic loading forces between 20 and 320N for 100,000, 200,000, 300,000, 500,000, and 1,000,000 cycles at frequencies 14Hz. Torque and detorque value after loading was measured. Results : All measued screws had different screw length and thread form. Titanium modified screw had greater detorque value than others before and after cyclic loadings(p<0.05). All abutment screws had no significant change in mean percentage of detorque value after loading to initial value after less than 500.000 cyclic loadings, but significant lower value after 1,000,000 cycles(p<0.05). Conclusion : Within limintations of this study all abutment screws may be loosend after about 1 year use. Annual check-up is nessasary to prevent screw loosening.

Full mouth rehabilitation of a severely worn dentition using intraoral scanner and the CAD/CAM double scanning technique

윤세나,한중석,여인성,윤형인,Yoon, Se-Na,Han, Jung-Suk,Yeo, In-Sung,Yoon, Hyung-In The Korean Academy of Prosthodonitics 2020 대한치과보철학회지 Vol.58 No.1

컴퓨터 지원 설계 제조 기술(CAD/CAM)의 발전에 따라, 완전한 디지털 워크플로우를 구현하기 위한 첫번째 단계인 구내스캐너의 중요성이 높아지기 시작했다. CAD/CAM 이중스캔 기술은 임시 수복물의 외형을 복제하여 최종 수복물에 반영하도록 하는 방법이다. 이 증례에서는 비심미적인 전치부, 중증도의 마모, 수직 고경의 감소를 보이는 67세 남성을 치관 연장술과 수직고경 회복을 동반한 완전구강회복을 통해 치료했다. 임시 수복물은 구내스캐너와 CAD/CAM 이중스캔을 이용해 제작되었다. 적응 기간 후, 최종 단일 구조 지르코니아 수복물을 CAD/CAM 이중스캔을 이용해 임시 수복물을 반영해 제작되었다. With the evolution of the computer-aided design/computer-aided manufacturing (CAD/CAM) technology, the intraoral scanners are playing an increasingly important role, as they are the first step towards a completely digital workflow. The CAD/CAM double scanning technique has been used to transfer the information from provisional restorations to definitive restorations. In this case, a 67-year-old male with esthetically compromised anterior teeth, generalized severe attrition of teeth, and reduced vertical dimension was treated with full mouth rehabilitation including a re-establishment of the lost vertical dimension of occlusion assisted by the crown lengthening procedure. The provisional restorations were fabricated using an intraoral scanner and the CAD/CAM double scanning technique. After the period of adaption, the definitive monolithic zirconia restorations were delivered. The CAD/CAM double scanning technique successfully transferred the occlusal and morphological characteristics, obtained from the provisional restorations, to the definitive restorations.