제 Ⅳ형 근관에서 System B tip의 깊이에 따른 근관 충전 효과

Abstract

The purpose of this study was to evaluate the effect of the apical sealing according to the depth of the System B tip when root canal was filled gutta-percha and sealer by Continuous Wave of Condensation technique in the Type Ⅳ canal. 50 simulated resin blocks with J-shaped curvature canals were instrumented by ProTaper (Dentsply Maillefer, Ballagiues, Switzerland) Ni-Ti files using the crown-down technique recommended by manufacturer. Type Ⅳ canals were made using a broken F3 ProTaper Ni-Ti file for making a ledge at 3mm short from the working length. And F1 ProTaper Ni-Ti file was used for perforating resin block. This perforating canal enlarged to MAF (#50) was considered as main canal and existing canal was considered as lingual canal. The prepared Type Ⅳ canals were randomly divided into three experimental groups of 15 each according to the depth of System B tip. ● Control - Cold lateral compaction (n=5) ● 3 mm Group - heat application upto 3mm short of the working length (n=15) ● 5 mm Group - heat application upto 5mm short of the working length (n=15) ● 7 mm Group - heat application upto 7mm short of the working length (n=15) All of experimental groups were obturated with Continuous Wave of Condensation technique using non-standardized gutta-percha cone (MAF #50) and AH-26 (Dentsply DeTrey, Johnson, Germany) as a root canal sealer. The length of gutta-percha and sealer in lingual of the Type Ⅳ canals was measured with a measuring digital calliper under magnifying glass (× 2.3). The datas were analysed statistically using one-way ANOVA and Turkey HSD test. The results are as follows : 1. In control group, there was no gutta-percha and sealer in lingual canal. 2. 3 mm group showed relatively more gutta-percha than 5, 7 mm group (p〈0.05) 3. 7 mm group did not showed gutta-percha and relatively more void were observed than 3, 5 mm group. (p〈0.05) In conclusion, within the limits of the results of this experiment, the 3 mm depth of System B tip was acceptable for obturating the Type Ⅳ canal.