Continuing Etching of an All-in-One Adhesive in Wet Dentin Tubules

Self-etch adhesives that etch and prime simultaneously are becoming more acidic. We hypothesized that the degree of acidic monomer conversion at the interface and within the tubules was high enough that the acidic reaction would be very self-limiting. Dentin surfaces prepared from extracted, unerupted human third molars were treated with Prompt L-Pop (3M ESPE). The prepared teeth were stored in normal saline, and specimens retrieved at intervals < or = 4 wks were randomly selected for light, scanning electron microscopic and micro-Raman spectroscopic analysis. Morphologic and spectroscopic analyses indicated dentin demineralization and adhesive penetration throughout the demineralized layer and tubules. Increased dentin demineralization and loss of adhesive integrity were noted after aqueous storage. The degree of monomer conversion at the interface was consistently greater than conversion within the tubules. Fluid within the tubules may inhibit monomer conversion. The acidic characteristics of this adhesive may be retained and, thus, continue to affect/demineralize the surrounding dentin.