Reply To: BC Liner, Conclusions and Clinical Tips (Part 8 of 8)

[Allen Ali Nasseh]

@Jason Wu: Like all dual cure resin ionomer cements expressed through a dual barrel syringe you have to make sure you bleed the syringe before you place the mixing tip on and then you have to express out the first drop of mixed material before you get to the proper mix. I’m sure you know what bleeding the syringe is but for anyone who doesn’t know it’s equal to expressing out a pea-size portion from both barrel to make sure you have material coming to the tip of the barrel and will get equal mix before securing the mixing tip in place. So, you have to express out and discard before you put the mixing tip and after you mix out of the mixing tip. BTW, this is not unique to this material but the proper protocol for all dual barrel syringe mixing tip initiated techniques since if you don’t do this you may get a lot of base to catalyst ratio and you won’t get a set.
The full setting time of the material would be around 4 minutes at body temperature. I use BC liner every day on almost 100% of cases to replace the idea of using Cavit. I just fill the whole chamber with the blue BC Liner after every root canal and ask the restorative dentist to remove 2-3mm from the surface of the Blue liner and use the rest as base to bond their core prior to a crown. So, after the root canal, I fill the chamber to the cavosurface with the liner and wait 40 seconds for it to do its self etching and self bonding routine before zapping the surface with 3 seconds of curing light so the surface which will be in contact with saliva when I remove the rubber dam would set but the rest below would self set and therefore have less polymerization shrinkage (less with self cure than with light). Anyway. In a couple thousand cases I’ve done this way I am yet to hear back from a referring dentist that the material was not set. If I use it as a provisional between visits or when patients come back for recall before getting the tooth restored I always find it fully set too. So, my assumption is that you either didn’t get a thorough mix (unequal mix of base-catalyst) or you had a bad batch somehow. Talk to your rep and give him/her your syringe so they can find out if the problem was the syringe or just the mixing. Cheers! 🙂