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      • KCI등재후보
      • KCI등재

        Characteristics of contact and distance osteogenesis around modified implant surfaces in rabbit tibiae

        최정유,심재혁,In-Sung Luke Yeo 대한치주과학회 2017 Journal of Periodontal & Implant Science Vol.47 No.3

        Purpose: Contact and distance osteogenesis occur around all endosseous dental implants. However, the mechanisms underlying these processes have not been fully elucidated. We hypothesized that these processes occur independently of each other. To test this, we used titanium (Ti) tubes to physically separate contact and distance osteogenesis, thus allowing contact osteogenesis to be measured in the absence of possible triggers from distance osteogenesis. Methods: Sandblasted and acid-etched (SLA) and modified SLA (modSLA) implants were used. Both types had been sandblasted with large grit and then etched with acid. The modSLA implants then underwent additional treatment to increase hydrophilicity. The implants were implanted into rabbit tibiae, and half were implanted within Ti tubes. The bone-to-implant contact (BIC) ratio was calculated for each implant. Immunohistochemical analyses of bone morphogenetic protein (BMP)-2 expression and new bone formation (Masson trichrome stain) were performed. Results: The implants outside of Ti tubes were associated with good bone formation along the implant surface. Implantation within a Ti tube significantly reduced the BIC ratio (P<0.001). Compared with the modSLA implants, the SLA implants were associated with significantly higher BIC ratios, regardless of the presence or absence of Ti tubes (P=0.043). In the absence of Ti tubes, the bone adjacent to the implant had areas of new bone formation that expressed BMP-2 at high levels. Conclusions: This study disproved the null hypothesis and suggested that contact osteogenesis is initiated by signals from the old bone that undergoes distance osteogenesis after drilling. This signal may be BMP-2.

      • KCI등재

        Spiral scanning imaging and quantitative calculation of the 3-dimensional screw-shaped bone-implant interface on micro-computed tomography

        최정유,Cham Albert Choi,In-Sung Luke Yeo 대한치주과학회 2018 Journal of Periodontal & Implant Science Vol.48 No.4

        Purpose: Bone-to-implant contact (BIC) is difficult to measure on micro-computed tomography (CT) because of artifacts that hinder accurate differentiation of the bone and implant. This study presents an advanced algorithm for measuring BIC in micro-CT acquisitions using a spiral scanning technique, with improved differentiation of bone and implant materials. Methods: Five sandblasted, large-grit, acid-etched implants were used. Three implants were subjected to surface analysis, and 2 were inserted into a New Zealand white rabbit, with each tibia receiving 1 implant. The rabbit was sacrificed after 28 days. The en bloc specimens were subjected to spiral (SkyScan 1275, Bruker) and round (SkyScan 1172, SkyScan 1275) micro-CT scanning to evaluate differences in the images resulting from the different scanning techniques. The partial volume effect (PVE) was optimized as much as possible. BIC was measured with both round and spiral scanning on the SkyScan 1275, and the results were compared. Results: Compared with the round micro-CT scanning, the spiral scanning showed much clearer images. In addition, the PVE was optimized, which allowed accurate BIC measurements to be made. Round scanning on the SkyScan 1275 resulted in higher BIC measurements than spiral scanning on the same machine; however, the higher measurements on round scanning were confirmed to be false, and were found to be the result of artifacts in the void, rather than bone. Conclusions: The results of this study indicate that spiral scanning can reduce metal artifacts, thereby allowing clear differentiation of bone and implant. Moreover, the PVE, which is a factor that inevitably hinders accurate BIC measurements, was optimized through an advanced algorithm.

      • SCIESCOPUSKCI등재

        Spiral scanning imaging and quantitative calculation of the 3-dimensional screw-shaped bone-implant interface on micro-computed tomography

        Choi, Jung-Yoo Chesaria,Choi, Cham Albert,Yeo, In-Sung Luke Korean Academy of Periodontology 2018 Journal of Periodontal & Implant Science Vol.48 No.4

        Purpose: Bone-to-implant contact (BIC) is difficult to measure on micro-computed tomography (CT) because of artifacts that hinder accurate differentiation of the bone and implant. This study presents an advanced algorithm for measuring BIC in micro-CT acquisitions using a spiral scanning technique, with improved differentiation of bone and implant materials. Methods: Five sandblasted, large-grit, acid-etched implants were used. Three implants were subjected to surface analysis, and 2 were inserted into a New Zealand white rabbit, with each tibia receiving 1 implant. The rabbit was sacrificed after 28 days. The en bloc specimens were subjected to spiral (SkyScan 1275, Bruker) and round (SkyScan 1172, SkyScan 1275) micro-CT scanning to evaluate differences in the images resulting from the different scanning techniques. The partial volume effect (PVE) was optimized as much as possible. BIC was measured with both round and spiral scanning on the SkyScan 1275, and the results were compared. Results: Compared with the round micro-CT scanning, the spiral scanning showed much clearer images. In addition, the PVE was optimized, which allowed accurate BIC measurements to be made. Round scanning on the SkyScan 1275 resulted in higher BIC measurements than spiral scanning on the same machine; however, the higher measurements on round scanning were confirmed to be false, and were found to be the result of artifacts in the void, rather than bone. Conclusions: The results of this study indicate that spiral scanning can reduce metal artifacts, thereby allowing clear differentiation of bone and implant. Moreover, the PVE, which is a factor that inevitably hinders accurate BIC measurements, was optimized through an advanced algorithm.

      • KCI등재

        Wear of 3D printed and CAD/CAM milled interim resin materials after chewing simulation

        Gerelmaa Myagmar,Jae-Hyun Lee,Jin-Soo Ahn,In-Sung Luke Yeo,Hyung-In Yoon,Jung-Suk Han 대한치과보철학회 2021 The Journal of Advanced Prosthodontics Vol.13 No.3

        PURPOSE. The purpose of this in vitro study was to investigate the wear resistance and surface roughness of three interim resin materials, which were subjected to chewing simulation. MATERIALS AND METHODS. Three interim resin materials were evaluated: (1) three-dimensional (3D) printed (digital light processing type), (2) computer-aided design and computer-aided manufacturing (CAD/CAM) milled, and (3) conventional polymethyl methacrylate interim resin materials. A total of 48 substrate specimens were prepared. The specimens were divided into two subgroups and subjected to 30,000 or 60,000 cycles of chewing simulation (n = 8). The wear volume loss and surface roughness of the materials were compared. Statistical analysis was performed using oneway analysis of variance and Tukey’s post-hoc test (α=.05). RESULTS. The mean ± standard deviation values of wear volume loss (in mm3) against the metal abrader after 60,000 cycles were 0.10 ± 0.01 for the 3D printed resin, 0.21 ± 0.02 for the milled resin, and 0.44 ± 0.01 for the conventional resin. Statistically significant differences among volume losses were found in the order of 3D printed, milled, and conventional interim materials (P <.001). After 60,000 cycles of simulated chewing, the mean surface roughness (Ra; μm) values for 3D printed, milled, and conventional materials were 0.59 ± 0.06, 1.27 ± 0.49, and 1.64 ± 0.44, respectively. A significant difference was found in the Ra value between 3D printed and conventional materials (P =.01). CONCLUSION. The interim restorative materials for additive and subtractive manufacturing digital technologies exhibited less wear volume loss than the conventional interim resin. The 3D printed interim restorative material showed a smoother surface than the conventional interim material after simulated chewing.

      • Comparison of micro-computed tomography and histomorphometry in the measurement of bone–implant contact ratios

        Choi, Jung-Yoo,Park, Jae-Il,Chae, Ji Soo,Yeo, In-Sung Luke Elsevier 2019 Oral surgery, oral medicine, oral pathology and or Vol.128 No.1

        <P><B>Objective</B></P> <P>The purpose of this study was to measure the 3-dimensional (3D) bone-to-implant contact (BIC) ratios calculated with an associated software algorithm on 3D micro–computed tomography (μCT) scans and compare them with measurements made with 2-dimensional histomorphometry.</P> <P><B>Study Design</B></P> <P>For uncomplicated calculation of the 3D BIC ratios, 16 implants (8 grade 2 titanium and 8 grade 4 titanium) with simple cylindrical geometry were inserted into 8 rabbit tibiae; 2 implants were inserted into each tibia. The experimental animals were sacrificed at 2 weeks after surgery. The implants were surgically removed en bloc with surrounding bone. 3D μCT images were acquired and reconstructed, and histomorphometric procedures were performed. The calculated 3D BIC ratios were compared with the histomorphometrically measured BIC ratios.</P> <P><B>Results</B></P> <P>When the 3D BIC ratios calculated in this study were compared with the BIC ratios measured conventionally by using histologic slides for light microscopy, no significant statistical correlation was found between the 2 ratios (<I>P</I> ≥ .35).</P> <P><B>Conclusions</B></P> <P>This study indicated that 3D μCT should be used for more accurate BIC assessment to produce an overall 3D picture for the bone–implant interface.</P>

      • SCIESCOPUSKCI등재

        A pilot study using machine learning methods about factors influencing prognosis of dental implants

        Ha, Seung-Ryong,Park, Hyun Sung,Kim, Eung-Hee,Kim, Hong-Ki,Yang, Jin-Yong,Heo, Junyoung,Yeo, In-Sung Luke The Korean Academy of Prosthodonitics 2018 The Journal of Advanced Prosthodontics Vol.10 No.6

        PURPOSE. This study tried to find the most significant factors predicting implant prognosis using machine learning methods. MATERIALS AND METHODS. The data used in this study was based on a systematic search of chart files at Seoul National University Bundang Hospital for one year. In this period, oral and maxillofacial surgeons inserted 667 implants in 198 patients after consultation with a prosthodontist. The traditional statistical methods were inappropriate in this study, which analyzed the data of a small sample size to find a factor affecting the prognosis. The machine learning methods were used in this study, since these methods have analyzing power for a small sample size and are able to find a new factor that has been unknown to have an effect on the result. A decision tree model and a support vector machine were used for the analysis. RESULTS. The results identified mesio-distal position of the inserted implant as the most significant factor determining its prognosis. Both of the machine learning methods, the decision tree model and support vector machine, yielded the similar results. CONCLUSION. Dental clinicians should be careful in locating implants in the patient's mouths, especially mesio-distally, to minimize the negative complications against implant survival.

      • KCI등재후보

        Considerations for the Survival of Complete Arch Implant-Supported Zirconia Restorations; Status of Antagonistic Arches and Stress Distribution on Frameworks: A Case Report

        Choi, Jung-Yoo,Sim, Jae-Hyuk,Yeo, In-Sung Luke Korean Academy of Dental Science 2017 Journal of korean dental science Vol.10 No.2

        This report describes two cases of complete arch implant-supported restorations. The first patient had seven dental implants in each arch with monolithic zirconia frameworks. At four weeks' follow-up, the one-piece maxillary framework was fractured, which was re-designed and re-fabricated using laser-sintered cobalt-chrome alloy. The second patient had four implants in the mandible only. A mandibular monolithic zirconia framework and a maxillary conventional complete denture were fabricated and delivered. At five years' follow-up, the patient reported no significant discomfort. Careful consideration and monitoring of the status of antagonistic arches and stress distribution on zirconia frameworks were suggested for complete arch implant-supported fixed restorations.

      • SCIESCOPUSKCI등재

        Characteristics of contact and distance osteogenesis around modified implant surfaces in rabbit tibiae

        Choi, Jung-Yoo,Sim, Jae-Hyuk,Yeo, In-Sung Luke Korean Academy of Periodontology 2017 Journal of Periodontal & Implant Science Vol.47 No.3

        Purpose: Contact and distance osteogenesis occur around all endosseous dental implants. However, the mechanisms underlying these processes have not been fully elucidated. We hypothesized that these processes occur independently of each other. To test this, we used titanium (Ti) tubes to physically separate contact and distance osteogenesis, thus allowing contact osteogenesis to be measured in the absence of possible triggers from distance osteogenesis. Methods: Sandblasted and acid-etched (SLA) and modified SLA (modSLA) implants were used. Both types had been sandblasted with large grit and then etched with acid. The modSLA implants then underwent additional treatment to increase hydrophilicity. The implants were implanted into rabbit tibiae, and half were implanted within Ti tubes. The bone-to-implant contact (BIC) ratio was calculated for each implant. Immunohistochemical analyses of bone morphogenetic protein (BMP)-2 expression and new bone formation (Masson trichrome stain) were performed. Results: The implants outside of Ti tubes were associated with good bone formation along the implant surface. Implantation within a Ti tube significantly reduced the BIC ratio (P<0.001). Compared with the modSLA implants, the SLA implants were associated with significantly higher BIC ratios, regardless of the presence or absence of Ti tubes (P=0.043). In the absence of Ti tubes, the bone adjacent to the implant had areas of new bone formation that expressed BMP-2 at high levels. Conclusions: This study disproved the null hypothesis and suggested that contact osteogenesis is initiated by signals from the old bone that undergoes distance osteogenesis after drilling. This signal may be BMP-2.

      • KCI등재후보

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