IDS is a universal concept whereby freshly cut dentin is sealed with an adhesive system immediately after preparation and before impression taking for indirect restorations.

There are 10 fundamental steps to achieve successful and predictable IDS :

  1. For endodontically treated teeth, a glass ionomer barrier is recommended to isolate the endodontic sealer from the solvent in the adhesive primer. (This step can be skipped for vital teeth).

  2. The dentin surface must be refreshed with a rough diamond bur (for total-etch adhesives) or carbide bur (for self-etch adhesives). Diamond burs produce a rougher surface (increased surface area) but also a more smear layer which is compatible with total-etch systems because they remove the smear layer. Self-etch adhesives, however, do not perform well in the presence of a thick smear layer. Thus, carbide multifluted burs are recommended with self-etch adhesives because a less smear layer is yielded. 

  3. The adhesive system is applied to the freshly cut dentin according to the manufacturer's instructions. Filled adhesives are preferred because they can be radiopaque and produce a more uniform resin coating. Air-thinning is not recommended in order to keep a consistent thickness of resin. The thicker layer of the adhesive resin is preferable in anticipation of airborne-particle abrasion just before restoration delivery. When using simplified and unfilled adhesive systems, it is recommended to protect the bonding resin by using a flowable liner. 

  4. Optional: Application and polymerization of composite resin additions to improve the preparation geometry, block the undercuts, reinforce the remaining cusps and, in certain cases, elevate deep margins.

  5. Air-blocking is performed. cover the entire preparation with glycerin gel and polymerize again to minimize the oxygen-inhibited layer. As such, it is essential to recognize the inhibitory effect on the polymerization of resins, which can easily reach up to a depth of 40 microns (compared to 1-3 microns for the hybrid layer) preventing the complete polymerization of resins and influencing the quality of adhesion to dentin.

  6. All enamel margins are refinished to eliminate any possible excess adhesive resin. 

  7. The preparation surface is gently pumiced to remove debris and remnants of the oxygen-inhibiting layer. If not removed, those remnants will interfere with the setting of silicone impression materials. This step can be skipped when using optical impressions.

  8. Final impression using preferably polyvinyl siloxane (PVS) materials. Polyether impressions should be avoided as they may adhere to the IDS layer unless IDS is completely covered with composite resin (regular or flowable).

  9. The tooth preparation is isolated with a layer of petroleum jelly before PMMA and resin-based provisional materials are applied because they can adhere to the IDS layer. Using a separating medium will facilitate the removal of provisional restorations when the patient returns for final restorations delivery.

  10. Careful airborne-particle abrasion of the preparation surface is performed just before restoration delivery (before enamel etching) in order to ensure a strong resin-to-resin bond. Air abrasion is followed by enamel etching/rinsing/drying and application of the adhesive resin to the entire preparation surface. No dentin primer is needed unless dentin has been omitted with the original IDS or re-exposed during the cleaning of the preparation.  


Biomimetic restorative dentistry. Pascal Magne, Urs Belser