• 대한치과보철학회지
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• 제47권3호
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• pp.266-272
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• 2009

연구목적: 전 세계적인 고령화 추세에 따라 무치악 환자들이 증가하고 이들의 임플란트 보철 수복에 대한 수요와 관심이 증가하고 있다. 부분 무치악 또는 완전 무치악에서 임플란트를 이용한 보철 치료는 효과적이며 그 성공율 또한 높게 보고되고 있다. 하지만 임플란트 사용 범위가 다양해짐에 따라 여러 가지 실패가 보고되고 이러한 실패를 줄이기 위한 방법들이 연구, 개발되고 있다. 이에 본 연구에서는 임플란트 생존율을 조사하고, 이를 토대로 향후 임플란트의 생존율에 대해 예측하고자 한다. 연구 방법: 1998년 8월부터 2003년 8월까지, 2003년 9월부터 2007년 4월까지 두 차례로 나누어 진료기록부 조사를 통해 최근 10년 동안 단국대학교 치과병원에서 임플란트를 치료받은 환자들의 임플란트 생존율에 대해 조사하였다. 결과: 진료기록부 조사를 통해 식립된 임플란트의 수, 임플란트 위치 및 분포, 1차 수술 후부터 2차 수술까지의 기간, 생존율 등을 조사하여 다음과 같은 결과를 얻었다. 1. 1차 조사에서 612명 환자에게 1680개의 임플란트가 식립되고, 2차 조사에서는 933명 환자에게 2438개가 식립되어 총 1545명의 환자에게 4118개 임플란트가 식립되었다. 2. 총 1545명 환자의 성비는 남성이 57.2% (884명), 여성이 42.8% (661명)였고, 총 4118개 임플란트에서 상악에 1739개 (42.2%), 하악에 2379개 (57.8%)가 식립되었으며 하악 구치부에 2043개 (53.2%)가 식립되어 제일 높은 비율을 차지하였다. 3. 1차 조사에서는 총 1680개의 임플란트 중 57개가 실패하였고 2차 조사에서는 2438개의 임플란트 중 17개가 실패하여 총 4118개의 임플란트 중 74개가 실패 하여 98.2%의 생존율을 보였다. 4. 1차 수술 이후 2차 수술이 시행되기까지의 기간은 상악에서 평균 7.4개월에서 6.8개월로, 하악에서 평균 5.6개월에서 5.0개월로 2차 조사 기간에서 0.6개월 단축되었다. 결론: 이상의 결과로 볼 때 1차 조사에서보다 2차 조사시에 식립된 임플란트의 수 및 생존율이 증가하였고 1차수술 후부터 2차 수술 전까지 기간도 단축되고 있음을 알 수 있었다. 앞으로도 임플란트에 대한 관심과 수요가 계속 증가 할 것이고 그 성공율 또한 증가하리라 사료된다.

• Journal of Periodontal and Implant Science
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• 제32권2호
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• pp.361-370
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• 2002

The aim of this study was to analyze various data of 120 non-submerged ITI implants placed in 64 korean adults. The data were retrieved from patients' charts and registered in the computer and coded for a statistical analysis. The results revealed that the most common type of edentulism was a distal extension case, and the largest number of implants were placed in the mandibular first molar position. Implants were placed more frequently in mandibular, posterior position than maxillary, anterior position, respectively. With respect to the implant diameter and length, an implant with 4.1mm in diameter and more than 10mm in length was the most common. Since a molar position was the most prevalent position for implant placement in korean patients, clinicians should be careful about implant diameter which can resist a strong occlusal force expected in the molar position. In addition, the distance to the mandibular canal and the floor of maxillary sinus should be considered to avoid possible damages, such as nerve injury and sinus perforation in selecting a proper implant length.

• Journal of Periodontal and Implant Science
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• 제35권3호
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• pp.777-788
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• 2005

The primary stability of implants is an important factor to predict the osseointegration. Recently, the resonance frequency analysis has been used to measure the primary stability. It is an objective method to monitor the stability of implants during healing phase. This study is to validate the differences in the effect of the osteotome method according to the bone quality as well the thickness of cortical bone. Two hundred seventy implants of 3.75mm in diameter(Neoplant, Neobiotech, Korea) were placed in 135 bovine ribs. The bone quality is classified into 3 classes according to the number of bone marrow spaces which implants would be placed, and then classified into 9 subclasses after the ribs were trimmed. Two implants were placed in 15 specimens of each class. The conclusion were as follows: 1. In case of less dense cancellous bone, the oseotome method is more effective in primary stability rather than the drilling method(p <0.05). 2. If there was cortical bone, it is more advantagous to get stronger primary stability. 3. If cancellous bone is more dense or if cortical bone exists, there is no statistical significance between drilling and osteotome method(p <0.05).

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제38권6호
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• pp.371-378
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• 2012

Many longitudinal studies have reported the successful osseointegration of dental implants, with survival rates approaching 90-95%. However, implants regarded as a "success" may have also failed to undergo osseointegration. A variety of complications and failures have been observed, including implant fracture - a rare and delayed biomechanical complication with serious clinical outcomes. Given the increasing popularity of dental implants, an increase in the number of failures due to late fractures is expected. This study sought to determine the rate of implant fractures and factors associated with its development. This retrospective evaluation analyzed implants placed at Wonkwang Dental Hospital (from 1996 to the present). In our study we found that the frequency of dental implant fractures was very low (0.23%, 8 implant fractures out of 3,500 implants placed). All observed fractures were associated with hybrid-surface threaded implants (with diameter of 4.0 or 3.75 mm). Prosthetic or abutment screw loosening preceded implant fracture in a majority of these cases.

• 대한치과보철학회지
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• 제36권4호
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• pp.615-643
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• 1998

The purpose of this study was to evaluate the effect of cantilever length, load, and implant number on the stress distribution of implant supported fixed prosthesis. In the replica of an edentulous human mandible, four or five implants were placed and spaced evenly between the mental foramina and symmetrical gold alloy cast superstructures with cantilever were fabricated. Strain gauges were placed in buccal and lingual side of implants. 9, 15, 21kg of loads at varying cantilever lengths were applied to the occlusal surface of fixed prostheses. The strains were recorded from each gauge and principal stresses were calculated The results were as follows : 1. Increasing the length of the cantilever increased the stresses on the bone supporting implants. and the ratio of increase became high as increasing the load. 2. In the model with four implants, the highest compressive stress was measured on lingual side of the first implants nearest loading point and the highest tensile stress was measured on buccal side of the second implants. 3. In the model with five implants, the highest compressive stress was measured on lingual side of the first implants nearest loading point. And the highest tensile stress was measured on buccal side of the second implants, and lingual side of the third implants. 4. There was no significant change of the magnitude of stress on the most distal imp]ant of non cantilevered side as increasing the cantilever length or load. 5. In general, the superstructure supported by five implants reduced the stress and was less affected by cantilever length compared to the support provided by four implants.

• 대한치과보철학회지
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• 제36권2호
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• pp.258-272
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• 1998

This investigation evaluated patients who received Steri-Oss implants from the Dental Hospital of Chosun University during the period from March 1989 to August 1997. 346 fixtures of 127 patients were included in this study. The results were as follows ; 1.The follow-up period was defined as the period between the surgical placement of the implants and the last follow-up examination. The mean follow-up period was $2.17{\pm}1.21$ years. 2.The period between fixture installation and second surgery was $0.71{\pm}0.44$ years in the maxilla and $0.46{\pm}0.21$ years in the mandible. 3.The number of fixtures which were installed in the upper jaw(112) was less than that in the lower jaw(234) and in the posterior region(260) was more than in the anterior region(86). 4.The length of fixture which was most frequently used was 12 mm and least was 8mm. Screw implants were installed more than cylindrical implants. 3.8mm implant was the most common implans, followed by 4.5mm and 3.25mm. 5.The number of augmentation cases was more than that of non-augmentation cases and the rate of augmentation cases in the maxilla was more than that in the mandible. 6.Implant restorations for partial edentulos patients(94cases) were more than single- tooth implant restorations(33cases) or implant restorations for complete edentulos patients(10cases). 7.Free-standing prostheses for partially edentulous patients were more commom than any other type of connection between implants and natural teeth. 8.Plaque Index($0.95{\pm}0.74$) and Gingival Index($0.31{\pm}0.52$) were very similar around the natural teeth and reflected an acceptable level of plaque and gingivitis control. Mean value for keratinized mucosa index($1.93{\pm}1.20$) remained fairly constant around level 2(1-2 mm keratinized epithelium). 9.Patients were generally satisfied with implant in terms of comfort, function, speech and esthetics. 10.There was not a statistically significant differences in overall survial rate between implants placed in the maxilla (91.5%) and those placed in the mandible (93.8%). Fourteen implants lost before the prosthetic rehabilitation and eleven implants lost following variable periods in function after the prosthetic phase of the treatment. 11.Cause of implant failures was exfoliation or removal of fixture due to non-osseointegration before the prosthetic rehabilitation or due to fracture of fixture, masticatory pain after the prosthetic rehabilitation. 12.The survival rate of Steri-Oss implants using the Kaplan-Meier statistical analysis was 93.8% at 2 year and 86.6% at 5 year, In all cases, implant losses occured predominantly in the healing period. There was a steep decline in the rate of implant loss after the first year. 13.The survival rate of Steri-Oss implants in the anterior region was 94.8% at 2 year and 94.8% at 5 year and that in the posterior region was 92.8% at 2 year and 75.9% at 5 year. In conclusion, this study revealed a number of parameters and guidelines for achieving an optimal success rate in osseointegration.

• 구강회복응용과학지
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• 제27권4호
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• pp.393-403
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• 2011

이 연구의 목적은 임상적으로 사용되는 RBM과 산부식 임플란트의 3년 생존율을 비교, 분석하기 위한 것이다. 총 152개의 RBM 임플란트를 식립하였고, 이 중 1개의 임플란트에서 실패가 발생하였는데, 원인은 식립체의 파절이었다. 또한 총 152개의 산부식 표면 임플란트를 식립하였는데, 이 중 7개의 임플란트에서 실패를 하였으며, 원인으로는 과열, 감염, 초기고정 불량 등이었다. RBM 임플란트의 생존율은 99.34%, 산부식 임플란트의 생존율은 95.39%로 두 가지 임플란트 모두 양호한 생존율을 보였으나, RBM 임플란트에서 다소 높은 생존율을 나타내었다.

• 구강회복응용과학지
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• 제19권3호
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• pp.195-206
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• 2003

Several factors can affect the formation of bone tissues surrounding implants. One of the factors is electrical stimulation. It is known to change the movement of cells, form and destroy cells, and alter concentration and chemical component of soft tissues and bones. The effect of electrical stimulation on bone formation can vary according to the intensity of electric currents, stimulating time, the method of sending electric currents, and tissues and cells currents are applied to. This study examines how various enviroments affect osteoblasts. (1) effect on osteoblast with varying intensity of currents Osteoblast-like cells were raised on four plates where implants can be placed. A constant current sink (MC3T3-E1) that can adjust the intensity and stimulating time of electric currents was used. The four plates were stimulated with $0{\mu}A$, $10{\mu}A$, $20{\mu}A$, and $40{\mu}A$, respectively. After 24 hours of stimulation, the number and distribution of cells surrounding implants were examined. (2) effect on osteoblast with varying conditions The 3 study was performed with same method. (1) The change of attached cell number 72-hour after application of various currents (2) The change of attached cell number 72-hour after application of various interval (3) The comparison of attached cell number by implant surface texture The following are the results: 1. The distribution and density of cells surrounding implant is highest under the intensity of electric currents of $20{\mu}A$. 2. The number of cells attached implants is highest under the intensity of electric currents of $20{\mu}A$. 3. The number of cells attached implants is highest under continous electric currents 4. The number of cells attached implants is not different by implant surface texture.

• Journal of Periodontal and Implant Science
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• 제47권1호
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• pp.2-12
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• 2017

The aim of this narrative review is to describe treatment options for the posterior regions of the mandible and the maxilla, comparing short implants vs. longer implants in an augmented bone. The dental literature was screened for treatment options enabling the placement of dental implants in posterior sites with a reduced vertical bone height in the maxilla and the mandible. Short dental implants have been increasingly used recently, providing a number of advantages including reduced patient morbidity, shorter treatment time, and lower costs. In the posterior maxilla, sinus elevation procedures were for long considered to be the gold standard using various bone substitute materials and rendering high implant survival rates. More recently, implants were even placed without any further use of bone substitute materials, but the long-term outcomes have yet to be documented. Vertical bone augmentation procedures in the mandible require a relatively high level of surgical skill and allow the placement of standard-length dental implants by the use of autogenous bone blocks. Both treatment options, short dental implants, and standard-length implants in combination with vertical bone augmentation procedures, appear to result in predictable outcomes in terms of implant survival rates. According to recent clinical studies comparing the therapeutic options of short implants vs. long implants in augmented bone, the use of short dental implants leads to a number of advantages for the patients and the clinician.

• 대한치과보철학회지
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• 제35권3호
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• pp.577-608
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• 1997

The purpose of this study is to evaluate the stress distribution in the bone around dental implants supporting mandibular overdenture according to the number of implant and the type of attachment. Two or four implants were placed in an edentulous mandibular model and three dimensional photoelastic stress analysis was carried out to measure the fringe order around the implant supporting structure and also to calculate principal stress components at cervical area of each implant. The attachments tested were rigid and resilient type of Dolder bar, Round bar, Hader bar and Dal-Ro attchment. The results were as follows ; 1. In 2-implant supported overdenture using Round bar, Hader bar, and Dal-Ro attachment, compressive stress pattern was observed on the supporting structure of implant on loaded side, while tensile stress pattern in unloaded side. 2. In 2-implant supported overdenture using Dolder bar, the rigid Dolder bar shared the occlusal loads between 2 implants in a more favorable manner than was exhibited by the resilient type, while the resilient type placed a more stress on the distocervical area of the implant on the loaded side. But compressive stress pattern was observed in both the loaded and unloaded sides in either case. 3. In 2-implant supported overdenture, rigid and resilient type of Dolder bar exhibited more cross arch involvement than the Round bar, Hader bar, or Dal-Ro attachment. 4. In 4-implant supported overdenture using resilient Dolder bar and Hader bar, stress turned out to be distributed evenly among the implants between loaded and unloaded side, but thor was no reduction in the magnitude of the stress in the surrounding structure of implant contratry to 2-implant supported overdenture. 5. The stress pattern at cervical area of implant was different with the number of implant or the type of attachment but the overload, harmful to surrounding structure of implant, was not observed.