The purpose of this study was to evaluate canal shaping ability and canal angulation change of K-file, straight endosonic K-file and precurved endosonic K-file.
Twenty staight canals and thirty curved canals were selected and divided into five groups according to canals curvature and canal instrumentation method. U1 group was prepared by straight endosonic K-file and H1 group by K-file in straigt canals.
U2
group was instrumented by straight endosonic K-file, U3 group by precurved endosonic K-file and H2 group by precurved K-file in curved canals.
Radiographs of canals were obtained before and after canal shaping. And postoperative radiographs were compared with preoperative radiographs using superimposition method.
@ES The results obtained were as follows;
@EN 1. In straight canals, K-file group demonstrated lager percentage of canal enlargement than endosonic K-file group on facial view, but reverse results exhibit on mesial view.
2. In curved canals, precurved K-file group showed largest percentage of canal enlargement, followed by precurved endosonic K-fine group and straight endosonic K-file group was smallest.
3. Percantage of canal enlargement at convex side was greater than at concave side in apical portion of each group. Especially in straight endosonic K-file group, percantage of canal enlargement at convex side and concave side showed sharply
difference.
4. In angulation change, the straight endosonic K-file group exhibited the greatest its change, followed by precurved endosonic K-file group and precurved K-file group was the least. Above results suggest that K-file is more effective endodontic
instrument than endosonic K-file, and that precurved file is effective for canal shaping in curved canal.
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