The objective is to fill the canal with gutta-percha points (cones) by compacting them laterally against the sides of the canal walls. The technique requires selection of a master point, usually one size larger than the master apical file, which should seat about 0.5 mm short of the working length (Fig. 3a). If the point is loose at working length, then either 1 mm should be cut from the tip and the point refitted to the canal, or a larger size point selected. It should be noted that gutta-percha points can not be as accurately machined as metallic instruments.
There may be variance in the size stated, and if a matched point does not fit a prepared canal it may be worth either trying another point from the packet, or fitting the point in a measuring/sizing gauge, as illustrated in Figure 4. Once the master point is fitted to length and demonstrates a slight resistance to withdrawal (tug-back), accessory points are then inserted alongside the master point and compacted laterally with a spreader until the canal is sealed (Fig. 3b).
The most simple system of accessory points designates these from A, the finest, through B and C to D, the largest, shown in Figure 5. As each point is used the prepared, flared, canal is becoming progressively wider, and the accessory points may therefore be used sequentially from small to large. The resultant filling appears above the access cavity as a spiral, with each point extruded slightly further out of the canal (Fig. 3c).
There are two main types of spreading instruments for compacting gutta-percha: longhandled spreaders and finger spreaders. The main advantage of a finger spreader is that it is not possible to exert the high lateral pressure that might occur with long-handled spreaders. The chance of a root fracture is reduced and it is therefore a suitable instrument for beginners.