The open apex, particularly in paediatric endodontics, can present a problem if it is too wide to permit the creation of a custom-fitted cone. A method of using the Obtura-II has been described whereby an increment of gutta-percha is applied to the canal close to the apex, and gently compacted with pluggers.
A rapid-developing radiograph is exposed to verify the position of the apical seal, and further compaction carried out if required.
Once the apical seal is intact the remainder of the canal may be filled with the Obtura-II in the normal way.