• 대한치과보철학회지
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• 제45권2호
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• pp.250-262
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• 2007

Statement of problem: It was reported high success rate of implant-supported fixed prostheses using with $5{\sim}6$ implants on anterior mandible. Recently, immediate loading protocol was focused to overcome disadvantages of classic 2-stage delayed loading protocol. Purpose: This clinical study was to evaluate stability changes with time of immediately loaded and delayed loaded implants in edentulous mandible and to compare stability changes with time according to implantation sites. Materials and methods: Five or six implants were placed on anterior mandible depending on the arch shape. The immediately loading group was consisted of 8 patients received their prostheses within $24{\sim}48$ hours after implantation. The delayed loading group was consisted of 8 patients received their definitive prostheses following classical prosthetic procedures after a healing period of 3 months. All patients were recalled every 6 months for check-up. The evaluations of radiographic examination, ISQ value measurement and recording of complication were done. To evaluate marginal bone level, intraoral periapical radiographs were taken with long cone paralleling technique. At every evaluation recall, all prostheses were removed and ISQ values were measured with OsstellTM on individual implants. Results: 1. None of implants was failed. All implants showed stable marginal bone levels and ISQ values. 2. Marginal bone level changes with time showed statistically significant difference between immediately loading group and delayed loading group (P<0.001). 3. ISQ value changes with time did not show statistically significant difference between immediately loading group and delayed loading group (P=0.079). ISQ value decreased with time in both groups, however, all implants showed stable ISQ value at 30 months-recall evaluation. 4. Marginal bone level changes with time did not show statistically significant differences among implantation sites (P=0.604). 5. ISQ value changes with time showed statistically significant differences among implantation sites (P=0.047). ISQ values of most posterior implants decreased with time comparing to other implants. Conclusion: Although the marginal bone level of the terminal abutment didn't different with the other implants, ISQ value of the terminal abutment was lower than that of the other implants. Therefore, further clinical evaluation would be needed in this point of view.

• The Journal of Advanced Prosthodontics
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• 제14권3호
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• pp.133-142
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• 2022

PURPOSE. A large number of studies have suggested the practicability and predictability of immediate implant function, but few studies have reported marginal bone level changes during sequential loading periods. The purpose of this study was to evaluate the marginal bone remodeling of immediately loaded self-tapping implants both at each time point and during each loading period between two time points. MATERIALS AND METHODS. The patients included in this retrospective study were treated with immediately loaded NobelSpeedy Replace implants between August 2008 and July 2009. Differences in the marginal bone level (MBL) at each time point and the marginal bone level change (ΔMBL) between two time points were analyzed with Bonferroni correction (P < .05). RESULTS. Overall, 24 patients (mean age, 47.3 ± 12.8 years) with 42 immediately loaded implants and a median follow-up of 6.5 years (IQR, 67.8 months) were included. The cumulative survival rate after 10 - 12 years was 95.2%. Continuous but slow marginal bone loss was observed during long-term follow-up. MBL at both 7.5 years and 11 years was significantly lower than that at loading, 6 months, 2 years and 4 years (P < .05). No bone loss difference was found in any period before 4 years of follow up (P > .05). The loading period of 4 years to 7.5 years showed the largest ΔMBL compared to those of other time periods (P < .05). CONCLUSION. Slight bone loss occurred continuously, and more radical changes of marginal bone can be observed during the period of 4-7.5 years. Thus, long-term effective follow-up of immediately loaded implants is needed.

• 한국항해항만학회지
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• 제30권6호
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• pp.491-498
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• 2006

컨테이너 터미널에서는 효율적인 선적 작업을 위해 선박이 입항하기 전 선박정보를 통해 선적 계획을 수립한다. 하지만 실제 선박이 터미널에 입항하여 안벽에 접안후의 실제 적재 상태가 계획 시점에서의 적재상태와 다르거나, 사전에 수립된 계획이 실행 불가능한 경우 등의 상황이 발생한다. 이에 따라 기존에 수립했던 계획을 즉각적으로 재수정 해야 하며, 이를 위한 해법의 연구가 필요하게 되었다. 이점에 착안하여 본 연구에서는 위에서 언급한 예기치 못한 상황에 대해 정리하고, 상황에 맞는 합리적이고 즉각적으로 활용이 가능한 실시간 선적계획 모델을 제시하였다.

• 동국한의학연구소논문집
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• 제8권2호
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• pp.83-96
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• 2000

이 실험의 목적은 탄수화물 부하식이요법시의 삼출건비방 투여가 달리기 선수의 뇨중 대사성분변화에 미치는 영향에 대해 관찰 연구한 것이다. 탄수화물 부하식이시 삼출건비탕(蔘朮健脾湯) 투여는 전해질대사 관련 변인에 있어서 $Na^+$, $Cl^-$, $K^+$, $Ca^{+ +}$에 유의성 있는 영향을 미쳤으며, 이는 세포막 투과성의 변화를 의미하는 것으로 $Na^+$-$K^+$ pump의 활성도가 증가하여 운동수행능력을 향상시킬 것으로 기대되나 추후 전해질 대사와 관련하여 renin, aldosterone 등의 호르몬 분비 기전에 관해서도 지속적인 연구가 진행되어야 할 것으로 사려된다.

• 한국임상수의학회지
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• 제27권1호
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• pp.55-61
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• 2010

Tooth restoration with implant placement have been interested in modern veterinary dentistry. It is important to reduce the interval between the tooth extraction and the insertion of the implants, to determine the restoration time after implant placement in dogs The aim of the this study was to compare the bone mineral apposition rate of immediately loaded implants with an unloaded control during the early healing state in the artificial extraction mandible. In four Beagles, two premolar sockets (PM2 and PM3) of the both sides of the mandible were installed with a one stage titanium mini-implant with a length of 11 mm and a diameter of 3.37 mm immediately after tooth extraction. Provisional restroration was given to implants, 3 weeks after implant placement in the left side (immediate loading) and 12 weeks in the right side (delayed loading), respectively. Radiographic and histologic examinations were performed. Radiographic evaluation revealed no significant difference between two groups. Bone-implant contact was $47.1{\pm}8.9$ in immediate loading and $50.2{\pm}8.2$ in delayed loading, interthread bone density was $78.7{\pm}10.9$ in immediate loading and $73.1{\pm}15.5$ in delayed loading, and peri-implant bone density was $95.4{\pm}7.1$ in immediate loading and $95.0{\pm}5.2$ in delayed loading, respectively. Three histologic analyses showed no significant difference between delayed and immediate loading. Followed by this study, the immediate loading of implants insterted into fresh extraction sockets after tooth extraction could be considered in veterinary dentistry.

• Journal of Periodontal and Implant Science
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• 제40권5호
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• pp.244-248
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• 2010

Purpose: The purpose of this study was to radiographically evaluate marginal bony changes in relation to different vertical positions of dental implants. Methods: Two hundred implants placed in 107 patients were examined. The implants were classified by the vertical positions of the fixture-abutment connection (microgap): 'bone level,' 'above bone level,' or 'below bone level.' Marginal bone levels were examined in the radiographs taken immediately after fixture insertion, immediately after second-stage surgery, 6 months after prosthesis insertion, and 1 year after prosthesis insertion. Radiographic evaluation was carried out by measuring the distance between the microgap and the most coronal bone-to-implant contact (BIC). Results: Immediately after fixture insertion, the distance between the microgap and most coronal BIC was $0.06{\pm}0.68\;mm$; at second surgery, $0.43{\pm}0.83\;mm$; 6 months after loading, $1.36{\pm}0.56\;mm$; and 1 year after loading, $1.53{\pm}0.51\;mm$ ($mean{\pm}SD$). All bony changes were statistically significant but the difference between the second surgery and the 6-month loading was greater than between other periods. In the 'below bone level' group, the marginal bony change between fixture insertion and 1 year after loading was about 2.25 mm, and in the 'bone level' group, 1.47 mm, and in 'above bone level' group, 0.89 mm. Therefore, the marginal bony change was smaller than other groups in the 'above bone level' group and larger than other groups in the 'below bone level' group. Conclusions: Our results demonstrated that marginal bony changes occur during the early phase of healing after implant placement. These changes are dependent on the vertical positions of implants.

• Journal of Periodontal and Implant Science
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• 제46권4호
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• pp.234-243
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• 2016

Purpose: Immediate loading of dental implants has been proved to be feasible in partially edentulous jaws. The purpose of this retrospective investigation was to assess the feasibility of immediately loading dental implants in fully edentulous jaws. Methods: A total of 24 patients aged between 53 and 89 years received a total of 154 implants in their edentulous maxillae or mandibles. Among the implants, 45 were set in fresh extracted sockets and 109 in consolidated alveolar bones. The implants were provisionally managed with chair-side made provisional resin bridges and exposed to immediate loading. Implants were followed up for 1-8 years, including radiographic imaging. Marginal bone levels were evaluated based on radiographic imaging. Results: A total of 148 out of the 154 implants survived over the follow-up period of 1 to 8 years, giving a survival rate of 96%. The time or region of the implantation, the pre-implant augmentation, and the length and diameter of the implants had no statistically significant influence on the survival or the success rate. The marginal bone level remained stable with only minimal loss of 0.3 mm after 60 months of loading. Conclusions: Within the limitations of this study, immediate loading is feasible for dental implants in edentulous jaws.

• The Journal of Advanced Prosthodontics
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• 제10권2호
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• pp.163-166
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• 2018

PURPOSE. The marginal bone loss of implants with laser treated surface was investigated after six weeks of loading after implant installation to the mandible molar area. MATERIALS AND METHODS. A total of 23 implants were placed in the edentulous molar area of the mandible: 13 implants were immediately loaded and 10 implants were early loaded. The implants used were made of titanium grade 23, screw shaped, 4.2 mm in diameter, and 10 mm in length. Patients were evaluated with resonance frequency analysis at implant fixture installation and 1, 2 (final prosthesis installation), 3, 5, 8, and 14 months later. X-rays were taken at 2 months after fixture installation and 1, 2, 3 years after to measure the marginal bone loss. RESULTS. The mean ISQ value measured at the implant installation was over 70 at all-time points. The average of marginal bone loss was average 0.33 mm. CONCLUSION. Immediate implant loading for laser treated implants would be possible.

• Smart Structures and Systems
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• 제1권2호
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• pp.141-158
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• 2005

A new design of distributed crack sensors based on the topological change of transmission line cables is presented for the condition assessment of reinforced concrete (RC) structures during and immediately after an earthquake event. This study is primarily focused on the performance of cable sensors under dynamic loading, particularly a feature that allows for some "memory" of the crack history of an RC member. This feature enables the post-earthquake condition assessment of structural members such as RC columns, in which the earthquake-induced cracks are closed immediately after an earthquake event due to gravity loads, and are visually undetectable. Factors affecting the onset of the feature were investigated experimentally with small-scale RC beams under cyclic loading. Test results indicated that both crack width and the number of loading cycles were instrumental in the onset of the memory feature of cable sensors. Practical issues related to dynamic acquisition with the sensors are discussed. The sensors were proven to be fatigue resistant from shake table tests of RC columns. The sensors continued to show useful performance after the columns can no longer support additional loads.

• Journal of Periodontal and Implant Science
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• 제46권3호
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• pp.152-165
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• 2016

Purpose: This study investigated the effects of bone density and crestal cortical bone thickness at the implant-placement site on micromotion (relative displacement between the implant and bone) and the peri-implant bone strain distribution under immediate-loading conditions. Methods: A three-dimensional finite element model of the posterior mandible with an implant was constructed. Various bone parameters were simulated, including low or high cancellous bone density, low or high crestal cortical bone density, and crestal cortical bone thicknesses ranging from 0.5 to 2.5 mm. Delayed- and immediate-loading conditions were simulated. A buccolingual oblique load of 200 N was applied to the top of the abutment. Results: The maximum extent of micromotion was approximately $100{\mu}m$ in the low-density cancellous bone models, whereas it was under $30{\mu}m$ in the high-density cancellous bone models. Crestal cortical bone thickness significantly affected the maximum micromotion in the low-density cancellous bone models. The minimum principal strain in the peri-implant cortical bone was affected by the density of the crestal cortical bone and cancellous bone to the same degree for both delayed and immediate loading. In the low-density cancellous bone models under immediate loading, the minimum principal strain in the peri-implant cortical bone decreased with an increase in crestal cortical bone thickness. Conclusions: Cancellous bone density may be a critical factor for avoiding excessive micromotion in immediately loaded implants. Crestal cortical bone thickness significantly affected the maximum extent of micromotion and peri-implant bone strain in simulations of low-density cancellous bone under immediate loading.