Penetration depth of warm vertical Gutta-Percha pluggers: impact of apical preparation

The warm vertical gutta-percha compaction technique requires canals to be sufficiently flared to allow the tip of the plugger to penetrate to the apical third. The aim of the present study was to determine whether apical preparation or finishing instruments could be used to improve the penetration depth of pluggers. Single-root canals (48) were prepared using different rotary Ni-Ti instruments: M File System (I), ProTaper (II), HEROShaper (III), and EndoK3 (IV). Finger and heat (Endotwinn) pluggers were introduced into the canals, one after the other, and their penetration depths were measured. The apical thirds of the canals were then flared with specific instrumentation and the penetration depths of the pluggers were once again measured. After the initial preparation, the smallest diameter pluggers (No. 1 and F) could be inserted 5 to 7 mm short of working length without difficulty. Apical flaring improved the maximum penetration depth of the finger plugger by 1.76 mm and the heat plugger by 1.52 mm The deepest penetration was obtained with the EndoK3, ProTaper, and HEROShaper instruments. By accentuating the taper, apical flaring facilitated the penetration of warm vertical gutta-percha compaction pluggers.