미니 임플란트 직경에 따른 피로파절강도의 비교 연구

허유리,손미경,김희중,최한철,정재헌 大韓齒科補綴學會 2012 대한치과보철학회지 Vol.50 No.3

Purpose: This study was conducted to obtain difference in fracture strength according to the diameter of one-body O-ring-type of mini implant fixture, to determine the resistance of mini implant to masticatory pressure, and to examine whether overdenture using O-ring type mini implant is clinically usable to maxillary and mandibular edentulous patients. Materials and methods: For this study, 13 mm long one body O-ring-type mini implants of different diameters (2.0 mm, 2.5 mm and 3.0 mm) (Dentis, Daegu, Korea) were prepared, 5 for each diameter. The sample was placed at 30 from the horizontal surface on the universal testing machine, and off-axis loading was applied until permanent deformation occurred and the load was taken as maximum compressive strength. The mean value of the 5 samples was calculated, and the compressive strength of implant fixture was compared according to diameter. In addition, we prepared 3 samples for each diameter, and applied loading equal to 80%, 60% and 40% of the compressive strength until fracture occurred. Then, we measured the cycle number on fracture and analyzed fatigue fracture for each diameter. Additionally, we measured the cycle number on fracture that occurred when a load of 43 N, which is the average masticatory force of complete denture, was applied. The difference on compressive strength between each group was tested statistically using one-way ANOVA test. Results: Compressive strength according to the diameter of mini implant was 101.5 ± 14.6 N, 149 ± 6.1 N and 276.0 ± 13.4 N, respectively, for diameters 2.0 mm, 2.5 mm and 3.0 mm. In the results of fatigue fracture test at 43 N, fracture did not occur until 2×106 cycles at diameter 2.0 mm, and until 5×106 cycles at 2.5 mm and 3.0 mm. Conclusion: Compressive strength increased significantly with increasing diameter of mini implant. In the results of fatigue fracture test conducted under the average masticatory force of complete denture, fracture did not occur at any of the three diameters. All of the three diameters are usable for supporting overdenture in maxillary and mandibular edentulous patients, but considering that the highest masticatory force of complete denture is 157 N, caution should be used in case diameter 2.0 mm or 2.5 mm is used. 연구 목적: 일체형의 o-ring type 미니 임플란트 고정체의 직경에 따른 파절강도의 차이를 비교하고자 한다. 연구 재료 및 방법: 길이 13 mm의 one body o-ring type의 미니 임플란트(Dentis, Daegu, Korea)를 직경2.0, 2.5, 3.0 mm 각각 5개씩 준비하였다. Instron universal testing machine 에 수직면에서 30도 각도로 샘플을 위치시키고 off-axis loading을 가하여 영구변형이 일어난 하중 값을 파절강도로 하고 5개의 시편의 평균을 구하여 각 직경에 따른 임플란트의 고정체의 파절강도를 비교하였다. 또한, 각 직경마다 3개의 시편을 준비하고 동적하중 피로 시험기를 이용하여, 파절이 발생할 때까지 파절강도의 80%, 60%, 40%의 loading 을 가하여 파절되는 cycle수를 측정하여 각 직경의 피로 파절을 분석하였다. 추가적으로 총의치의 평균 저작력인 43 N의 하중을 가하여 파절되는 cycle 수를 측정하였다. 각 군간의 차이를 검증하기 위해서 일원분산분석(one-way ANOVA test)을 시행하였고, 통계처리는 SPSS ver.12 (SPSS Inc. Chicago, IL, USA) 을 이용하여 실시하였다. 결과: 직경 3.0 mm 의 미니 임플란트는 평균 276.0 ± 13.4 N의 압축력을 받았을 때 영구 변형이 일어났고 직경 2.5 mm 미니 임플란트가 149.0 ± 6.1 N, 2.0 mm 미니 임플란트가 101.5 ± 14.6 N일 때 영구 변형이 일어났다. 각 군간의 파절강도에는 유의한 차이가 있었다(P<.001). 총의치의 평균 저작력 하중에서 실시한 피로 파절 실험 결과, 세직경 모두 5×106 cycle까지 파절이 일어나지 않았다. 결론: 미니 임플란트의 정적 하중 하에서 최대 압축강도는 직경이 증가할수록 유의적으로 증가하였다. 최대 압축강도는 세 직경 모두 총의치의 평균 저작력 보다는 크나 최대 교합력보다는 직경 3.0 mm에서만 크게 나타났다. 총의치의 평균 저작력 하중에서 실시한 피로 파절 실험 결과, 세 직경 모두 파절이 일어나지 않았다.

Evaluation of Dental Implant Stability with or without Photoactivated Surface Treatment

허유리,강재석,손미경 대한구강악안면임플란트학회 2021 대한구강악안면임프란트학회지 Vol.25 No.2

Purpose: This study aimed to evaluate the stability of two implant groups treated either only with sandblasting and acid etching or photoactivation after sandblasting and acid etching, using resonance frequency analysis (RFA). Materials and Methods: We investigated 50 implants in 25 patients (12 men and 13 women). Twenty-five implants were treated with sandblasting and acid etching, and 25 with photoactivation. We recorded the implant stability quotient (ISQ) value on the day of implant placement and consecutively every 2 weeks for 16 weeks for each implant. RFA was used for the direct measurement of implant stability. We compared mean ISQ values using a repeated-measures analysis of variance test. Results: The mean ISQ values at surgery and 16 weeks in implants treated only with sandblasting and acid etching were 77.8 ± 6.7 and 83.2 ± 2.5, respectively, while in those treated with further photoactivation were 78.9 ± 5.3 and 84.1 ± 3.3, respectively. The photoactivated implants showed higher ISQ values than those without photoactivated surface treatment. However, there were no significant differences between the two implant groups. Conclusion: Both implant groups showed high implant stability in clinical practice. The photoactivated implant surface appears to have higher implant stability than that without photoactivation by increasing the hydrophilic surface.

Removable partial denture restoration using implant-supported surveyed crowns

허유리 조선대학교 치의학연구원 2022 Oral Biology Research (Oral Biol Res) Vol.46 No.4

Conventional dentures and implant-fixed prostheses are the treatment of choice for patients with multiple missing teeth. Implantassisted removable partial dentures (IARPD) represent a viable treatment option that combines these two treatment modalities to provide greater retention and stability compared to dentures alone. IARPDs also offer enhanced esthetic characteristics in patients with severe bone loss, and treatment outcomes can be improved further through careful diagnosis taking the degree of bone loss and the patient’s facial features into consideration. Accurate implant placement that is compatible with the partial denture design and the opposing dentition is also crucial for success. The current clinical series includes patients that underwent partial denture treatment using implant-supported surveyed crowns, and presented satisfactory functional and esthetic treatment outcomes.

Contour of lingual surface in lower complete denture formed by polished surface impression

허유리,김희중,손미경,정재헌 대한치과보철학회 2016 The Journal of Advanced Prosthodontics Vol.8 No.6

PURPOSE. The aim of this study was to analyze the shapes of lingual polished surfaces in lower complete dentures formed by polished surface impressions and to provide reference data for use when manufacturing edentulous trays and lower complete dentures. MATERIALS AND METHODS. Twenty-six patients with mandibular edentulism were studied. After lower wax dentures were fabricated, wax was removed from the lingual side of the wax denture and a lingual polished surface impression was obtained with tissue conditioner. The definitive denture was scanned with a three-dimensional scanner, and scanned images were obtained. At the cross-sections of the lingual frenum, lateral incisors, first premolars, first molars, and anterior border of the retromolar pads, three points were marked and eight measurements were taken. The Kruskal-Wallis test and a post hoc analysis with the Mann-Whitney test were performed. RESULTS. Each patient showed similar values for the same areas on the left and right sides without a statistically significant difference. The height of the contour of the lingual polished surface at the lingual frenum was halfway between the occlusal plane and lingual border, it moved gradually in a downward direction. The angle from the occlusal plane to the height of the contour of the lingual polished surface was increased as it progressed from the lingual frenum towards the retromolar pads. CONCLUSION. The shape of the mandibular lingual polished surface was convex at the lingual frenum, lateral incisors and gradually flattened towards the first molars and retromolar pads.

구개인두 기능부전을 갖는 구개열 환자에서 폐쇄장치를 이용한 보철 치료 증례

허유리,김종욱,이경제,정재헌,Heo, Yu-Ri,Kim, Jong-Wook,Lee, Gyeong-Je,Chung, Chae-Heon 대한치과보철학회 2013 대한치과보철학회지 Vol.51 No.4

Cleft lip and palate is congenital deformity in oral and maxillofacial area. Normal soft palate has velopharyngeal closure action by connecting oral cavity and nasal cavity at rest and moving upward at swallowing and specific pronunciation. Cleft palate patients with velopharyngeal insufficiency have difficulty in mastication, swallowing and pronunciation because velopharyngeal closure is incomplete. At this time, a prosthetic device used to cover palate defects is called a palatal obturator. A palatal obturator separates oral cavity and nasal cavity and recovers pronunciation, mastication, swallowing and esthetic function. The purpose of this case study is to report the results because it reaches a satisfactory result in functional and esthetic aspects through functional impression procedures using modeling compound and tissue conditioner for restoration of a cleft palate patient with velopharyngeal insufficiency. 구순 구개열은 구강 악안면 부위에 발생하는 선천적 기형이다. 정상적인 연구개는 휴식 시에는 구강과 비강을 연결해 주고, 연하나 특정 발음 시에는 상방으로 이동하여, 구강과 비강을 분리하는 구개인두 폐쇄 운동을 한다. 구개인두 기능부전을 갖는 구개열 환자에서는 이 운동이 불완전하여 저작, 연하, 발음 시에 어려움을 겪는다. 이때, 구개 결손부를 폐쇄하기 위해 사용하는 보철물을 구개 폐쇄장치라고 한다. 구개 폐쇄장치는 구강과 비강을 분리하여 발음, 저작, 연하, 심미적 기능을 회복한다. 본 증례의 환자는 구개인두 기능부전을 갖는 선천적 구개열 환자로 구개인두 폐쇄를 이루기 위하여 모델링 콤파운드와 점막 조정재를 이용한 기능인상 과정을 시행하여 제작한 구개 폐쇄장치를 장착하여 기능적인 면과 심미적인 면에서 만족할만한 결과를 얻었기에 이를 보고하는 바이다.

항공 종사자가 인지한 신 환경 패러다임과 ESG 경영의 속성이 항공사 ESG의 진정성과 조직 충성도에 미치는 영향

허유리,심미영,김하니 한국관광학회 2024 한국관광학회 국제학술발표대회 Vol.95 No.-

의료서비스에서의 UX

허유리 한국HCI학회 2014 한국HCI학회 학술대회 Vol.2014 No.2

밀도기반 혼합 POI추천 시스템

허유경(Yu-kyung Heo),오주성(Joo-Seong Oh),퍼우델(Prabesh Paudel),타파(Prakash Thapa),전혜지(Hye-Ji Jeon),정민아(Min-A Jeong),이성로(Seong-Ro Lee) 대한전자공학회 2015 대한전자공학회 학술대회 Vol.2015 No.6

본 논문은 사용자에게 더 적합한 관심지점 (POI)추천을 위해 밀도기반 혼합 POI 추천 시스템을 제안한다. GPS 데이터를 입력받고 머무른 지점(Stay Point)를 계산한 다음 다양한 클러스터링 방법을 통해 POI를 추출하는 기존의 자동 POI 추천 연구와 사용자가 지정하여 POI 를 추천하는 지정 POI연구를 혼합한 방법으로 초기 파라미터에 사용자가 지정한 POI를 입력하므로써 사용자에게 더욱 적합한 POI를 추천 할 수 있으며 클러 스터링 방법으로 밀도기반 클러스터링인 DBSCAN을 사용하여 다양한 모양과 크기의 요이를 추천할 수 있게 하였다. 이는 초기 데이터에서 사용자의 요구를 반영하여 볼륨을 줄여줌으로써 시스템 구현시 사용되는 자원과 시간을 줄일수 있고 사용자의 요구에 적합한 POI를 추천 할 수 있다.

중소유역의 일별 용수수급해석을 위한 하천망모형의 개발(I) - 중소유역의 일유출량 추정 -

허유만,박창헌,박승우 한국농공학회 1993 韓國農工學會誌 : 전원과 자원 Vol.35 No.1

The Objectives of this paper were to develop a modified tank model that is capable of simulating daily streamflow from a small watershed using daily watershed evapotranspiration and to test the applicability of the model to different watersheds. Tank model was restructured to consist of three series of tanks, each of which may mathematically reflect watershed runoff mechanisms from different components of surface runoff, interflow, and baseflow. And pan evaporation was correlated to potential evapotranspiration estimated from a combination method, and was multiplied by monthly crop and landuse coefficients, and watershed storage coefficient to estimate the watershed evapotranspiration losses. Ten watersheds were selected to calibrate model parameters that were defined using an optimization scheme, and the results were correlated with watershed parameters. Simulated daily runoff was compared to the observed ones from the tested watersheds. The simulating results were in good agreement with the observed values when optimal and calibrated parameters were used. Ungaged conditions were also applied to compare simulated values to the observed. And the results were in fair conditions for all the tested watersheds which differ considerably in their sizes, landuse types, and physiological features.

맵리듀스를 이용한 대용량 선박 기자재 관리

허유경(Heo You Kyung),오주성(Oh Juseong),박진관(Park Jingwan),김영주(Kim Yeongju),정민아(Jeong Mina) 한국통신학회 2014 한국통신학회 학술대회논문집 Vol.2014 No.11