The previously described System-B achieves an excellent and controlled obturation of the apical 5 7 mm of the root canal. At this point the canal is quite wide, and can accept the tip of the Obtura s needle. A film of sealer is applied to the canal wall. The machine is heated to 200 C. A small amount of the warm gutta-percha should be extruded to warm the needle and discarded. The needle is then quickly introduced to the canal. If this part of the protocol is not followed, a void may result between the two parts of the filling.
The trigger is activated and thermoplasticised gutta-percha extruded into the canal, gently pushing the needle out. Once the canal is filled conventional pluggers may be used to compact the gutta-percha,
which is finally sealed with glass ionomer as usual.