A simple modification to the cold lateral compaction technique is to apply heat to the guttapercha. The softened material is easier to compact and will result in a denser root filling. However, finger spreaders will not retain heat sufficiently for this procedure, and specially designed heat carriers should be used. The instruments illustrated in Figure 8 have a sharp tip for lateral compaction, and a blunt plugger tip for limited vertical compaction of the softened gutta-percha. Electrically heated spreaders are also available.
It is important that the instruments are only gently warmed. If the spreader is too hot it will melt the gutta-percha,
which will adhere to the instrument and be withdrawn from the canal.