• Restorative Dentistry and Endodontics
• /
• v.26 no.5
• /
• pp.418-435
• /
• 2001

Root canal preparation process is of utmost importance in successful treatment of root canal. Also, one of the most important purpose of the root canal preparation is to enlarge the root canal three dimensionally without changing the curvature of the root canal However as the curvature of the root canal increases, there are many difficulties involved in formation of optimum root canal. Therefore in order to solve the above mentioned problems, new developments in methods of root canal preparation and equipments for such purposes were made. Recently, vigorous studies about newly introduced engine-driven nickel-ti-tanium rotary file are conducted. As shown in research results to dates, it is well established that the use of nickel-titanium file is better suited for curved root canal than stainless steel file in maintaining the curvature or root canal and reducing the deformation of root canal. However it is also acknowledged that there are a few discrepancies in research results according to protocol, due to failure to remove variables in experiments. In addition, although it is recommended by the manufacturer that the GT rotary file should maintain a low rotational speed of 150~350rpm and 'light pressure' as light as not to break the lead of a pencil, academic studies about the vertical force which is not yet standardized are not sufficiently explored. Therefore, this research devised and utilized a special research equipment to standardize the appropriate range of vertical force for GT rotary file through experiments by breaking of the lead of a pencil as expressed by the manufacturer and to accurately measure factors involved through repeating and recreating the environment of root canal preparation. Forming nine experimental groups by varying the vertical forces (150g. 220g, 300g) and rpm (150rpm, 250rpm, 350rpm), the effects of changing vertical forces and rpm on working efficiency were measured in terms of time expended in root canal preparation by crown-down method using a transparent resin block with 35 degree curvature and GT rotary file (z-test). The following research using this special research equipment that involved nine experimental groups and varying the vertical force for root canal preparation from 300g which is within the normal vertical force range to 700g and 1000g which fall outside the normal rpm range. The results were as follows : 1. Analysis of the experiment results revealed that the time spent in root canal preparation decreased as the vertical forces and rpm increased (p<0.05). Also, the effects of rpm were greater than those of the vertical forces within the normal vertical force range ($\beta$-weight test). 2. Observation of the deformation of GT rotary file revealed that deformation increases in a direct correlation with the vertical force increase and in a reverse correlation with the rpm decrease. In the case of the vertical forces close to the normal range, the probability of GT rotary file deformation were quite different depending on the rpm changes. In the case of greater vertical forces, the occurrences of deformation of the file were more frequent regardless of the rpm changes. 3. Deformation and breakage of file were also commonly observed in the expended time measurement experiments and GT rotary file deformation experiments in which low speed rpm (150rpm) was used and at the curved portion of the resin block.

• Journal of Digital Convergence
• /
• v.12 no.3
• /
• pp.391-397
• /
• 2014

This paper is concerned with medical tourism, which is expected to become the new growth engine of the 21st century. Medical tourism is a collaborative and synergistic composition of Healthcare and Tourism, and has led to a remarkable growth in 2012 since the year 2009, exhibiting huge growth potential. This paper reviews the emerging market of the medical tourism with five major hospitals in Korea from the perspective of medical tourists, and makes suggestions for the global health care and the sustainable development in Korean medical tourism as a growth market: the construction of websites for active services and transparent management of medical expenses with proper arrangement of medical consulting and advices, cooperation of the health care center and the medical tourism industry, and the activation of healthcare communication. For the smooth progress of medical tourism, this paper suggests two separate communication channels: one for the patient tourists and the other for the medical tourism coordinators. The former needs accuracy with professional knowledge on the healthcare and communication, which should be classified as medical interpreters working with disease-oriented medical tourists. The latter refers to international medical coordinators dedicated to the smooth progress of medical tourism and services. This paper also points out the creative efforts to improve the relatively poor infrastructure of tourism industry to accommodate the medical tourists, and improve the medical tourism industry.