Resin Coating (RC)
Equally important as immediate dentin sealing, resin coating (RC) uses flowable composite to begin the bond to dentin without stressing the developing hybrid layer during polymerization. When done with the best materials and protocols, resin coating can increase the strength of a bond to dentin by 400%. This step creates the “secure bond” (Jayasooriya PR, Pereira PNR, Nikaido T, Tagami J. Efficacy of a Resin Coating on Bond Strengths of Resin Cement to Dentin. J Esthet Restor Dent 2003 15(2) 105-113) to dentin, which means any restorative failures happen above the bond, in the restorative material, rather than below the bond in healthy tooth structure.
This case by Dr. Davey Alleman, DMD shows the steps of immediate dentin sealing, resin coating and air abrasion to create a biobase.
Using flowable composite for resin coating
Flowable composite is used for the resin coating step in a biomimetic restoration. When researching ways to improve bonding predictability, Dr. David Alleman recognized how the time required to place flowable composite gave developing bonds time to mature, leading to his formulation of the Hierarchy of Bondability.
Resin coating example by Dr. Davey Alleman, DMD.
How a resin coating “fail safe” improves dental restorations
Resin coating bonds to the dentinal bonding agents to create the biobase. Once a biobase is established, a tooth is fully connected around the pulp chamber just like a natural tooth. Restoring a tooth using Dr. David Alleman’s Six Lessons Approach protocols create the strongest bond between the dentin, dentin bonding agent and resin coat. Bonds above the resin coat within the dentin and enamel replacements are weaker, creating a “fail safe” so any clinical failures occur above the resin coat. This protects the remaining healthy tooth structure and makes for easy repairs to the enamel replacement.
Slide from the Biomimetic Mastership showing a “good” failure where the healthy tooth structure is preserved.
Oxygen inhibition layer
Oxygen inhibition during immediate dentin sealing stops polymerization in the top 10-15 microns of a dentinal bonding agent. Adhesive thickness can minimize the impact of oxygen inhibition to overall bond strength, but the best way to increase the bond strength to dentin is to complete a resin coating step, which will allow full polymerization of the adhesive.
Fiber placement and resin coating
For teeth that are structurally compromised or have caries sealed near the pulp, placing fiber, such as Ribbond, can improve bond strength within the biobase. Fiber is placed during the resin coating step within the central stop zone to help reinforce weaker bonds and diffuse strain to the hybrid layer.
Ribbond is placed in the central stop zone in this case by Dr. Davey Alleman, DMD.
Learn more about resin coating technique and its application within a biomimetic restoration to help eliminate post operative sensitivity and debonded restorations in upcoming Alleman Center biomimetic dentistry training programs.
Learn more about resin coating in this Six Lessons Approach Podcast episode.
