Exploring the nature of acid-resistant hybrid layer with wet bonding.

The nature of the hybrid layer (HL) following chemical treatment has not been resolved. The effects of chemical treatments and polishing on HL morphology and composition were investigated using micro-Raman spectroscopy and SEM. Polished and unpolished SingleBond adhesive/dentin (a/d) interfaces from the same tooth were randomly selected for one of the following treatments: a) 5N HCl followed by 5%NaOCl; b) 5%NaOCl; c) 5%NaOCl and sonication; d) 5%NaOCl followed by 5N HCl. The results indicated that the HCl-NaOCl treatment could obscure the "true" HL in the unpolished a/d interfaces that were actually porous. The composition and morphology of the polished interface specimens were largely unchanged by the above treatments. Descriptions of HL quality are commonly based on the acid reactivity of polished specimens. The results of this study indicate that polishing dramatically alters the native composition, increasing its acid-resistance, and thus, this procedure could lead to false conclusions about HL quality.

RCT Entities:   Population Interventions Outcomes