• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.4
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• pp.423-439
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• 2012

This case report described a technique utilizing a computer-aided design (CAD)/computer-aided machining (CAM) - guided surgical implant placement and prefabricated temporary fixed prosthesis for an immediately loaded restoration. The advantages of CAD/CAM guided implant procedures are flapless, minimally invasive surgery and shorter surgery time. With this technique, less postoperative morbidity and delivery of prosthesis for immediate function would be possible. A patient with an edentulous maxilla received 8 implants in maxilla using CAD/CAM surgical templates. Prefabricated provisional maxillary implant supported fixed prosthesis were connected immediately after implant installation. Provisional prosthesis was evaluated for aesthetics, function during 6 months. Definitive implant supported fixed porcelain fused metal bridges were fabricated.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.3
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• pp.288-295
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• 2019

Passive fit of prosthesis is an essential property of implant supported prosthesis for long term success and minimization of complications. And the property is determined mostly by fabrication procedure. There were limitations of extensive implant prosthesis because conventional casting method generate contraction error of long span prosthesis. However, Computer-aided design/Computer-aided manufacturing (CAD/CAM) technology of 3D printing and milling metal framework can overcome those limitations. This case is a full mouth rehabilitation using extensive implant fixed prosthesis. Removable interim prosthesis was made for esthetic, functional evaluation and a guide for implant insertion. After the insertion, implant fixed interim prosthesis was delivered. After additional evaluation and adjustment, final prosthesis was designed with CAD, the fabricated with CAM. Milling technique was used for anterior screw type implant superstructure and 3D printing technique was used for the anterior and posterior implant copings. Fit of the final restoration was favorable. The practitioner and patient were both esthetically and functionally satisfied with the final result.

• Journal of Dental Rehabilitation and Applied Science
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• v.38 no.4
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• pp.213-221
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• 2022

Purpose: The efficacy of the amount of sealer in the root canal and two retreatment NiTi file systems in removing filling materials. Materials and Methods: Extracted premolars with a single root canal were selected for this study. After access opening and root canal preparation up to size #40/.06, the specimens were randomly divided into four groups. Gutta percha (GP) tapers of .06 or .04 were used for each group and filled using a single-cone filling technique with CeraSeal, a calcium silicate-based sealer. Each group was retreated either using the ProTaper Universal Retreatment System (PTUR) or the Hyflex Remover (HR). The time taken to remove the filling material, the amounts of apically extruded debris, and canal cleanliness were measured and compared. Results: The amount of sealer did not affect the efficiency when removing the filling materials. However, the filling material was removed faster in the HR group than in the PTUR group. Two types of NiTi files showed similar retreatment effects in the amounts of apically extruded debris and in the degree of canal cleanliness. Conclusion: The amount of sealer in canal filling had no significant effect on retreatability. Retreatment with HR removed filling materials is faster than PTUR. There was no difference in other removal efficiencies according to the type of retreatment NiTi file.

• Restorative Dentistry and Endodontics
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• v.47 no.4
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• pp.40.1-40.18
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• 2022

Objectives: This study aimed to investigate the influence of different obturation techniques compared to cold lateral compaction on the success rate of primary non-surgical endodontic treatments. Materials and Methods: Systematic searches were performed for studies published up to May 17^th, 2022 in MEDLINE/PubMed, Cochrane Library, Web of Science, Scopus, EMBASE, and Grey Literature Reports. Randomized clinical trials and nonrandomized (nonrandomized clinical trials, prospective or retrospective) studies that evaluated the success rate of primary non-surgical endodontic treatments obturated with the cold lateral compaction (control) and other obturation techniques were included. The revised Cochrane risk of bias tools for randomized trials (RoB 2) and nonrandomized studies of interventions (ROBINS-I) were used to evaluate the risk of bias. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) tool was used to evaluate the certainty of evidence. Results: Eleven studies (4 randomized clinical trials (RCTs), 4 prospective, and 3 retrospectives) were included. Two RCTs were classified as having some concerns risk of bias and 2 as a low risk of bias. Two nonrandomized studies were classified as having a critical risk of bias and 5 as having a moderate risk of bias. The GRADE analysis demonstrated a very low to moderate certainty of evidence. Conclusions: This systematic review generally evidenced no differences in the success rate of primary non-surgical endodontic treatments when the cold lateral compaction technique and other obturation techniques are performed. Further well-designed studies are still necessary.

• Journal of the Korean institute of surface engineering
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• v.48 no.2
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• pp.43-49
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• 2015

This study reports a fabrication of $TiO_2$ on the surface of dental implants by pulsed d.c. magnetron sputtering from a Ti target. A systematic investigation on the microstructure and mechanical properties of $TiO_2$ films was carried out with the variation of $O_2$ contents and substrate temperatures. The effects of deposition parameters on the fabricated structures were investigated by X-ray diffraction (XRD) technique and field emission scanning electron microscope (FE-SEM). Hydrophilic properties were evaluated by measuring water contact angles on the film surface. With increasing $O_2$ contents up to 40%, surface roughness of $TiO_2$ film increased while relatively smooth surface was obtained with 50% $O_2$ contents. Surface roughness and adhesion strength both increased as substrate temperature increased up to $200^{\circ}C$. From these results, hydrophilic and adhesive properties of the present $TiO_2$ films synthesized with 40% $O_2$ at $200^{\circ}C$ are regarded to be suitable for bio-compatible applications.

• Journal of the Korea Society of Computer and Information
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• v.18 no.9
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• pp.177-187
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• 2013

Association rule mining is a popular data mining technique with a wide range of application domains, and aims to extract the cause-and-effect relations between the discrete items included in transaction data. However, analysts sometimes have trouble in interpreting and using the plethora of association rules extracted from a large amount of data. To address this problem, this paper aims to propose a novel approach called HTM for extracting the interesting association rules from given transaction data. The HTM approach consists of three main steps, hierarchical clustering, table-view, and mosaic plot, and each step provides the analysts with appropriate visual representation. For illustration, we applied our approach for analyzing the mass health examination data, and the result of this experiment reveals that the HTM approach help the analysts to find the interesting association rules in more effective way.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.24 no.2
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• pp.122-133
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• 2015

The requirements for the successful treatment of all-ceramic restorations are not so different from the ones of conventional restorations. "The provisional restoration followed by an adequate tooth reduction" and "the accurately fitting prostheses with corresponding to final impression" can be the examples of them. Nevertheless, the one which all-ceramic restorations are distinguished from conventional restorations is the additional procedure of so called "bonding". In addition to the application of resin cement between "inner surface of restoration and outer surface of abutment", bonding technology can be also applied to the treatment process of "Post and Core" in particular if the abutments are non-vital teeth. Core build-up for all-ceramic crown is conducted with fiber post and tooth colored composite by considering the properties of the restorations transmitting light. We know well that a vital abutment is easier than a non-vital one to get the targeted goals for clinical success in connection with esthetics and structure. The creation of "Post and Core" with bonding technique is a decisive factor for a long-term success if the abutment is non-vital tooth with dentinal collapse. I would like to share my clinical experience about "post & core build-up and all-ceramic restoration bonding" out of several success strategies of all-ceramic crown with this review article.

• The korean journal of orthodontics
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• v.37 no.1 s.120
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• pp.73-84
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• 2007

The maxillary protraction headgear has been widely used in the treatment of skeletal Class III children with maxillary deficiency. A variety of treatment objectives which allow dentoalveolar movements may be established, but when only maxillary protraction without dentoalveolar movement is needed, one of the limitations in maxillary protraction with conventional tooth-borne anchorage is the loss of dental anchorage. This is because a bone remodeling occurs not only at circummaxillary sutures but also within the periodontal tissues. During protraction treatment in the mixed dentition phase, in older children or for the patient with multiple congenitally missing teeth, it is not uncommon to observe undesirable mesial movement of maxillary teeth. Such a side effect can be eliminated or minimized using absolute anchorage such as skeletal anchorage. The purpose of this case report is to introduce a new technique of the maxillary protraction headgear treatment using surgical miniplates.

• Imaging Science in Dentistry
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• v.47 no.2
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• pp.99-107
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• 2017

Purpose: Erosions and osteophytes are radiographic characteristics that are found in different stages of temporomandibular joint (TMJ) osteoarthritis. This study assessed the effectiveness of digital subtraction radiography (DSR) in diagnosing simulated osteophytes and erosions in the TMJ. Materials and Methods: Five intact, dry human skulls were used to assess the effectiveness of DSR in detecting osteophytes. Four cortical bone chips of varying thicknesses (0.5 mm, 1.0 mm, 1.5 mm, and 2.0 mm) were placed at the medial, central, and lateral aspects of the condyle anterior surface. Two defects of varying depth (1.0 mm and 1.5 mm) were created on the lateral, central, and medial poles of the condyles of 2 skulls to simulate erosions. Panoramic images of the condyles were acquired before and after artificially creating the changes. Digital subtraction was performed with Emago dental image archiving software. Five observers familiar with the interpretation of TMJ radiographs evaluated the images. Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic accuracy of the imaging methods. Results: The area under the ROC curve (Az) value for the overall diagnostic accuracy of DSR in detecting osteophytic changes was 0.931. The Az value for the overall diagnostic accuracy of panoramic imaging was 0.695. The accuracy of DSR in detecting erosive changes was 0.854 and 0.696 for panoramic imaging. DSR was remarkably more accurate than panoramic imaging in detecting simulated osteophytic and erosive changes. Conclusion: The accuracy of panoramic imaging in detecting degenerative changes was significantly lower than the accuracy of DSR (P<.05). DSR improved the accuracy of detection using panoramic images.

• Journal of Periodontal and Implant Science
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• v.48 no.4
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• pp.202-212
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• 2018

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.