DentAI – Immediate Dentin Sealing (IDS) and Resin Coating

In dentAI #17. We continue through David Alleman's six-lesson biomimetic series. In this part we discuss IDS and resin coating.

What is Immediate Dentin Sealing (IDS)?

Definition: IDS means performing the bonding steps immediately after tooth preparation.
Steps: This process usually includes conditioning (for example, with total-etch or self-etch systems), priming, and applying an adhesive layer of appropriate thickness onto freshly cut dentin.
Benefits: IDS allows the dentin bond to reach its maximum potential strength in a stress-free environment, free from the influence of polymerization stress or C-Factor forces.
This IDS forms the first layer of the Biobase, which will be explained further later.

Three dentin bonding systems are considered the gold standard for performing IDS: Optibond FL, Clearfil SE Protect, and Clearfil SE Bond.
Usage techniques: The techniques for using these systems vary greatly, and a deep understanding of dental materials and their interactions with the various hard dental tissues is essential.
Example: Optibond FL uses the total-etch technique, whereas Clearfil SE Protect uses the self-etch technique.

Enamel and dentin are primed for 20 seconds and then air-dried for 10 seconds to evaporate the solvent.
The adhesive is then applied as a uniform layer, and excess adhesive is removed with a clean, dry microbrush.
The adhesive layer is not air-dried, in order to prevent further oxygen inhibition.
The adhesive layer is cured for 20 seconds.
The Clearfil SE Protect adhesive layer is thinner than that of Optibond FL, so applying a resin coating (RC) layer is recommended when Clearfil SE Protect is used (explained in the resin coating section).
Gold-standard bonding systems can achieve bond strengths close to the DEJ (approximately 50 MPa).
The bond strength potential to dentin is greater than to enamel.
With correct techniques, sound superficial dentin has twice the bond strength potential of enamel. This again relates to the Hierarchy of Bondability (HOB).

Time required for dentin bond maturation: As discussed earlier, the dentin bond needs time to reach its maximum strength.
Bulk-fill technique and the shift of the material's center of mass: If a bulk-fill technique is used and the forming dentin bond is immediately connected to enamel, the center of mass of the composite moves away from the forming dentin bond (which needs more time to mature) and toward the enamel bond, which matures faster.
Cause of the shift: This happens because enamel is dry while dentin is moist and flexible.
Gap formation: With the premature connection of these very different substrates, the restorative material separates from the forming hybrid layer, and a gap then forms at the base of the cavity.
Post-operative sensitivity: Clinically, these gaps can lead to the classic post-operative sensitivity commonly seen with composite restorations.

Definition: Resin Coating (RC) is a technique in which 0.5 mm of microfilled and flowable composite is placed over the IDS layer.
Benefits of resin coating:
Reducing the thickness of the oxygen-inhibited layer: It reduces the thickness of the oxygen-inhibited layer.
Increasing the time for dentin bond maturation: It provides more time for the development of the dentin bond and the maturation of the hybrid layer.
Preventing transudation (pulpal fluid movement): It prevents transudation (pulpal fluid movement) through the IDS layer.
Forming part of the Biobase: It forms part of the Biobase.
When a restoration is placed over an optimally executed IDS and RC layer, the bond strength to dentin is cohesive.

Dr. Foad Shahabian Prosthodontist & Implant Specialist