모형레진 근관에서 엔진 구동용 니켈-타이타늄 파일의 경사도의 차이에 따른 근관성형력의 비교

COMPARISON OF SHAPING ABILITY OF NICKEL-TITANIUM ROTARY FILES WITH DIFFERENT TAPER IN SIMULATED RESIN CANALS

The aim of this study was to compare shaping ability of nickel-titanium rotary files with different taper in simulated resin canals. The instruments used in this study were GT with .04 taper ProFile with ISO-sized tip, .04 taper ProFile with ISO-sized tip alone, and .02 taper Naviflex file and all canals were prepared by crown-down technique. A total of 30 composite images were made from pre- and post-canal scanned images using Scanjet 4C scanner and Corel photopaint 8.0 and then, prevalence of canal aberrations was measured. The amount of coronal substance the instruments removed was also calculated two-dimensionally on digitized images with the Brain C software to compare the relative enlarging efficiency. Finally, the prepared internal canal form was evaluated three-dimensionally with impression technique. The results were as follows; 1. The incidence of zipping in Naviflex group was significantly high compared to the other two groups(P<.05). 2. The amount of coronal substance the GT combined group removed was significantly larger than the other two groups(P<.05). 3. The GT combined group produced canals with good taper and flow. Under the conditionas of this study, the combined use of larger tapered nickel-titanium rotary files prepared simulated canals safely, efficiently and with good three-dimensional form.