According to Dr John Kanca DDS, if you co-cure the adhesive with the flowable composite or packable composite, it will result in increased bond strength. That is in stark contrast to how most dentists will light cure each layer individually.
The co-curing technique
Regardless of what bonding you're using and also what composite you're using, this technique can still be implemented. Although you do need to clean out the cavity first prior to implementing this technique.
How to do it:
Apply your conditioner and primer.
Apply the adhesive or bonding layer but DO NOT LIGHT CURE.
Place flowable composite directly into the adhesive.
Light cure for specified amount of time.
Now you can place your packable composite like you usually do.
As per Dr Kanca, doing it this way helps to increase the bond strength when compared to curing the adhesive and composite separately. He had studies on it back when apexdental still had a functioning forum but it has since merged with Vista to become Vista Apex.
Additional benefit
Aside from the extra bonding strength, co-curing the two layers together also produces a more radiopaque layer on the pulpal floor.
The x-ray above shows what it can look like when Simplicity adhesive is co-cured with Titan flowable composite. The bottom most pulpal layer has a distinct radiopaque layer.
We mention this because most adhesives are radiolucent.
If your bonding layer is too thick, it may show up as a thick radiolucent line.
The thick radiolucent line can be mistaken as recurrent decay.
Therefore, doing it this way eliminates that ambiguity.
Takeaway
If you co-cure the adhesive with the first composite layer, it will help increase the bonding strength of the restoration. That results in a stronger and more stable composite filling.
The co-curing is how we bond in the first layer for all composites and that includes core buildups. Yes, we even use this technique prior to placing all of the core buildup material!
Our dentists in Long Island City been doing this for many years now with a lot of success. If you come in for a dental filling you can rest assured that we will try to give it the strongest bond strength as possible.
