Interfacial Chemistry of Universal Self etch Adhesives After Prior Dentin Acid etching

Abstract

C.T. TEGERDINE

Self-etch and total-etch adhesives bond composites to enamel and dentin, however, neither is

sufficient to ideally bond to both dental substrates. Selectively total-etching enamel has been

suggested to improve self-etch bonding ability to enamel, but because of its difficulty, prior acid

etching of dentin occurs. Universal self-etch adhesives have been developed to work as total-etch

or self-etch to address this issue. Little is known about the bonding interface of the new products

with acid etched dentin. Objectives: The purpose of this study was to examine the interfacial

chemistry and morphology of a universal self-etch adhesive on dentin and compare how it

performs to a total-etch adhesive. Methods: Fifteen teeth were subjected to prior acid etching

and then applied with Single Bond Plus, Scotchbond Universal (without Rubbing), and

Scotchbond Universal (with Rubbing). Teeth were sectioned and examined using Raman

microspectroscopy, differential Goldner's trichrome staining, and scanning electron microscopy.

Results: Scotchbond Universal showed a significantly thicker interface (one-way ANOVA with

Tukey-Kramer post hoc test, α=0.05), a better penetration profile, and similar hybrid layer

morphology when compared to Single Bond Plus. A rubbing technique was found to be

important for the application of Scotchbond Universal; without rubbing caused the adhesive to

de-bond and separate from dentin. Conclusions: The results suggest that Scotchbond Universal

performed similarly to Single Bond Plus with no adverse effects from prior acid etching. The

clinician does not have to be as accurate when performing selective enamel etching. Funded by

UMKC SOD Summer Scholars Program.