Step 10 – Master Cone Selection
Non-standardized cones (fine, fine-medium, etc) or .04 tapered cones can be selected if the root canal was prepared using the Wave One files because these cones will better match the taper of the prepared canals than the standardized cones (.02 taper). A Gutta-Percha gauge is a helpful tool in assuring that the tip of the cone is the same size as the final file. The gutta-percha gauge is a piece of plastic that has holes corresponding to the diameter of file sizes. Simply take the cone and place it in the brass insert that matches the diameter of the final file and cut off any excess from the bottom using scissors or a scalpel. The cone can be pinched with the cotton pliers to mark the working length and should fit snugly in the canal with a little tug-back. The medium fine, fine and fine medium sizes are most often appropriate for taper and the clinic also has a selection of cones with an .04 taper.
Clinic Tip: Always fit gutta percha cones in a moist canal to get the proper feel of tug back. This also extends the contact time between bleach and the root canal wall.
Standardized ISO-sized cones can be selected to match the ISO-size of the final file used in the preparation. The same technique can be used with the gutta-percha gauge to fit the cone to working length and size the apical diameter. You can use these cones when rotary files were not used during preparation or in the event that you can’t fit one of the non-standardized cones to working length.
Take an X-RAY to confirm proper fit of the cones.
Finally, prior to final obturation and to complete the cleaning and shaping, irrigate the canals very well for the last time and dry using paper points that have been measured to the working length. It is helpful to take your cotton pliers and make a dent or bend in the paper points to assure yourself that you are going to the proper working length.
Step 11 – Mixing Cement
Automix Ribbon is the sealer used at Pacific. To mix the sealer, simply dispense the appropriate amount of the expressed ribbon on your glass slab. Be sure to remove the cement with alcohol IMMEDIATELY after you use it or it can ruin the instruments or your glass slab.
Step 12 – Lateral Condensation / Obturation
Using paper points, apply sealer to the canal walls. Coat the master cone with sealer and introduce it into the canal with a slight circular motion to allow any air or excess sealer to escape in a coronal direction. Next, insert the spreader into the canal to condense the master cone laterally and vertically. Leave the spreader in the canal until you are ready to insert the next cone. Remember the next cone is going to be inserted in the void left by the spreader. If you remove the spreader too soon the void will fill in with sealer before you have a chance to place the accessory point. When you have coated the next cone and are ready to place it, remove the spreader by rotating it 180˚ back and forth to dislodge it from the canal. Let the spreader release by frictional heat (i.e. do not pull it out). Repeat this until you have about 3 accessory points in each canal and take an X-RAY.
If you have a good apical fill, sear off the excess gutta-percha sticking out of the canals so that you have better vision. Continue to condense until the spreader can only be inserted into the canals about 2mm. At this point, use a hot plugger to compact the gutta-percha points into the most coronal part of the canals and sear off any excess material.
Clinic Tip: Make sure that your plugger is hot enough (red hot) to sear off the gutta percha and work quickly before it cools. If the instrument isn’t hot enough, or you leave it in place and let it cool, there is a risk of pulling out all of the gutta percha you just placed.
Clean the access cavity using cotton pellets dipped in alcohol to remove any excess sealer. You can also clean the walls of the access cavity by refining with a diamond bur. The floor of the chamber can be sealed using a dentin-bonding agent or you may temporize the preparation using CAVIT or KETAC.
Step 13 – Final Post-Operative Radiograph
After placing the temporary remove the rubber dam and clamp and take a final X-RAY to be archived In axiUm.