GT rotary file을 이용한 근관성형법과 충전방법의 비교

Abstract

The purpose of this study was to compare the shaping time of two shaping methods and the leakage of three different obturation techniques. Ninty three canaled human molar teeth were used, which were randomly divided into two groups of forty teeth each and ten control teeth. After working length determination, the one group was prepared crown-down technique using rotary root canal instruments of GT rotary files .12/20, .10/20, .08/20 and .06/20 taper(Maillefer Instrument SA. Switzerland). The other group was instrumented with Gates Glidden burs(#1, #2, and #3) to coronal preparation and GT rotary files .08/20 and .06/20 taper to apical preparation. Shaping time was measured.After root canals were instrumented, they were divided to three subgroups and obturated as follows: Subgroup 1, obturated with single cone method : Subgroup 2, obturated with lateral condensation : Subgroup 3, obturated with continuous wave technique. Three subgroups were obturated using non-standardized gutta-percha cone(Diadent, Korea, .06 or .08 taper) and AH-26(Dentsply DeTrey, Germany) as a root canal cement.Ten unobturated teeth served as positive and negative controls. After immersion in 2% methylene blue solution for 1 month, the teeth were washed during 24h. The teeth were demineralized in 10% nitric acid and dehydrated by immersion in 80, 90 and 100% ethyl alcohol. The teeth were finally cleared and stored in 100%methylsalicylate, and apical dye penetration was evaluated under stereomicroscope(Leica M420 ,LC, U.S.A)at ×8.75 magnification.Liner measurement of dye penetration was assessed with the use of digitalized image analysing system (analySIS, GmbH, Germany). The data were analysed statistically using independent T-test and Two-way ANOVA and Tukey test.