• Journal of the Korean Society of Radiology
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• v.13 no.4
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• pp.581-588
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• 2019

MRI is superior when contrasted to help the organization generate artifacts resolution, but also affect the diagnosis and create a image that can not be read. Metal is inserted into the tooth, it is necessary to often be inhibited in imaging by causing the geometric distortion due to the majority and if the difference between the magnetic susceptibility of a ferromagnetic material or paramagnetic reducing them. The purpose of this study is to conduct a metal artefact in accordance with the analysis using a diamagnetic material. The magnetic material include a wire for the orthodontic bracket and a stainless steel was used as a diamagnetic material was used copper, zinc, bismuth. Testing equipment is sequenced using 1.5T, 3T was used was measured using a SE, TSE, GE, EPI. A self-produced phantom material was used for agarose gel (10%) to a uniform signal artifacts causing materials are stainless steel were tested by placing in the center of the phantom and cover inspection of the positive cube diamagnetic material of 10mm each length.After a measurement artefact artifact zone settings area was calculated using the Wand tool After setting the Low Threshold value of 10 in the image obtained by subtracting images, including magnetic material from a pure tool phantom images using Image J. Metal artifacts occur in stainless steel metal artifact reduction was greatest in the image with the bismuth diamagnetic materials of copper and zinc is slightly reduced, but the difference in degree will not greater. The reason for this is thought to be due to hayeotgi offset most of the susceptibility in bismuth diamagnetic susceptibility of most small ferromagnetic. Most came with less artifacts in image of bismuth in both 1.5T and 3T. Sequence-specific artifact reduction was most reduced artifacts from the TSE 1.5T 3T was reduced in the most artifacts from SE. Signal-to-noise ratio was the lowest SNR is low, appears in the implant, the 1.5T was the Implant + Bi Cu and Zn showed similar results to each other. Therefore, the results of artifacts variation of diamagnetic material, magnetic susceptibility (${\chi}$) is the most this shows the reduced aspect lower than the implant artificial metal artifacts criteria in the video using low bismuth susceptibility to low material the more metal artifacts It was found that the decrease. Therefore, based on the study on the increase, the metal artifacts reduction for the whole, as well as dental prosthesis future orthodontic materials in a way that can even reduce the artifact does not appear which has been pointed out as a disadvantage of the solutions of conventional metal artifact It is considered to be material.

• Journal of Korean Academy of Dental Administration
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• v.5 no.1
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• pp.1-12
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• 2017

Although dental hygienists have performed chair-side assisting and other dental cares as well as preventive dental cares in Korea, medical technician law confines duties of dental hygienists as closed narrative. The aim of this study was to investigate difference in perception of duties of dental hygienists in dental clinic between dentists and dental hygiene students. A total of 245 copies of questionnaires were distributed to dentists and students by post-mail. Only 42 dentists and 30 students in an area replied these questionnaires about the present and future duties of dental hygienists after providing written consent. Both groups agreed that intra and extra oral X-ray taking, education about oral health behavior, instruction after dental treatment, chair-side assisting, consulting for patients, scaling, initial impression taking, management of dental materials and equipment, sterilization of equipment, and receiving dental bills are duties of dental hygienists. However, they had different perceptions about various dental treatments as duties of dental hygienists even if they were under instructions of a dentist, including infiltration anesthesia, filling in cavity, intramuscular injection, FC change, canal irrigation, orthodontic treatment including separating, ligature bracket bonding and removing, setting crown and bridge, making individual, removing implant screw, and so on. These findings demonstrated that there were different perceptions about duties of dental hygienists between dentists and dental hygiene students, especially on dental treatment.