Interactions between impression materials and immediate dentin sealing

Statement of problem

Immediate dentin sealing is a new strategy in which a dentin bonding agent is applied to freshly cut dentin and polymerized before making an impression. Interactions are suspected between the resin coating and the impression material.

Purpose

The purpose of this study was to identify possible interactions between 2 impression materials and resin-coated tooth surfaces using 2 different dentin bonding agents.

Material and methods

Extracted molars (n=6) with flat midcoronal preparations underwent 1 of 4 procedures: control group, unsealed tooth surface/impression; IDS group, immediate dentin sealing (Optibond FL or Clearfil SE Bond)/impression; IDS/AB group, immediate dentin sealing/air blocking/impression; IDS/AB-P group, immediate dentin sealing/air blocking/pumicing/impression. All specimens underwent impressions (Impregum Soft or Extrude). Optical microscopy was used to detect unpolymerized and residual impression material on the bonded tooth surface.

Results

A substantial layer of unpolymerized resin (oxygen-inhibited layer) was found in the IDS group, which resulted in100% faulty impressions (unpolymerized impression material) for both adhesives and impression materials. Air blocking the resin coating (IDS/AB group) did not completely eliminate the oxygen-inhibited layer of Optibond FL and slightly altered the surface of SE Bond (wrinkles). Only SE Bond along with Extrude generated ideal impressions in group IDS/AB, while all other combinations of adhesive/impression material resulted in faulty impressions (unpolymerized impression material or adhesions). The IDS/AB-P group yielded ideal Extrude impressions but generated faulty Impregum impressions (adhesions) in more than 50% of the specimens.

Conclusions

Immediate dentin sealing should be followed by air blocking and pumicing to generate ideal impressions with Extrude. Impregum is not recommended in combination with immediate dentin sealing. (J Prosthet Dent 2009;102:298-305)