3-D OBTURATION
How do I know when I'm ready to pack?
What sealer do you recommend and why?
Kerr Pulp Canal Sealer EWT (Extended Working Time) because of the following features:<\p>
- Excellent flow
- Variable viscosity
- Non-cytotoxic
- Non-resorbable
- Heat activated
- Blocks pain
- Sets fast
When using a warm gutta percha hydraulic obturation technique it is routine to observe a sealer puff associated with a portal of exit. Surplus sealer after filling is well-tolerated and research supports its biocompatibility. Advantageously, zinc oxide and eugenol form zinc eugenates which block prostogladins and pain. Patients are more comfortable post-operative when a sealer sets rapidly and completely in the periradicular tissues. Classic sealers take 24-48 hours to set, a more recently marketed sealer, AH Plus, sets in approximately 6 hours, and Kerr Pulp Canal Sealer sets in less than 2 hours.
Is it possible to utilize the Calamus Flow to completely fill the canal rather than just using it for the backfill? Also, I would like to know whether sealer is a must?
I personally always fit a master gutta percha cone, thermosoften and remove gutta percha segments with the Calamus Pack (Dentsply Tulsa Dental), use prefit pluggers to generate waves of condensation, and continue this process to within 5mm of the apical foramen. When the downpack is completed, I then backpack with the Calamus Flow (Dentsply Tulsa Dental). I always use sealer (Kerr Pulp Canal Sealer EWT) and butter the cone before inserting it into the canal. I am aware of the philosophy of using only the Calamus Flow (or other backfill device) to completely fill a canal; however, you will not achieve multiple waves of condensation, the same magnitude of hydraulics, or consistent apical control as compared to fitting a master cone. If you have a smooth flowing tapered shape why not fit a master cone!
In a past issue of Dentistry Today I read about a technique for backfilling in a single step using the Obtura gun: 1) Insert the needle to the coronal aspect of the previously downpacked gutta percha core; 2) Wait 5 seconds; 3) Inject slowly, and allow the extruded gutta percha to back the needle out of the canal; 4) Condense the gutta percha at the orifice level using a large plugger. I have used this technique on several cases, and have seen no voids. My question is this: If lateral canals are filled by the hydraulic force generated on the downpack, do you see a problem with using this technique?
Remember, gutta percha holds heat over a distance of only 3-5 mm. The technique you described is fine if you are only judging your backpack based on radiographic voids. If you backpack the entire coronal two-thirds of a canal and only compress the thermosoftened gutta percha at the orifice level then shrinkage should be expected. Pluggers compress, mold and adapt gutta percha to the configuration of the canal. Importantly, plugger pressure offsets shrinkage during the cooling cycle. I recommend backpacking in 3-5 mm increments, using a sized plugger after each squirt, until you reach the orifice level. On occasion I do fill a lateral canal on the backpack that I did not get on the downpack. This is not the norm, but something to think about.
What are your concerns with Thermafil? It looks good on an xray, but is it really well condensed in the canal?
The obturation potential is dependent on the quality of the shaping. Well-shaped canals become well-packed canals. If you have the shape, then studies have shown that carrier-based obturation techniques can three-dimensionally obturate a root canal.