Apparent conversion of adhesive resin in the hybrid layer, Part II: In situ studies of the resin-dentin bond

✍ Scribed by Yuan Zou; Julie L. P. Jessop; Steven R. Armstrong

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 139 KB
• Volume: 89A
• Category: Article
• ISSN: 1549-3296
• DOI: 10.1002/jbm.a.31954

✦ Synopsis

Abstract

Penetration and conversion of adhesives into the hybrid layer (HL) is important to the quality and longevity of the adhesive resin (AR)‐dentin bond. In this study, a methodology is developed to examine the degree of conversion and relative HEMA concentration with respect to Bis‐GMA using Raman spectroscopy. This methodology will be used in the future reports related to this topic. Conversion in the AR of water‐stored resin‐dentin samples (84% ± 3%) agreed well with that measured in commercial adhesive (Comm Adh) resin samples after 24‐h water storage (80% ± 2% from Part 1) and was significantly higher than Comm Adh without water storage (58% ± 3% from Part 1) (p = 0.0005). Adhesive conversion was not significantly different (p = 0.5036) through the middle of the HL, with a mean of 83% ± 6%. HEMA mole fraction, relative to Bis‐GMA, was significantly higher (p = 0.0028) in the top half of the HL (0.67 ± 0.03), when compared to HEMA in the AR (0.60 ± 0.01). HEMA and EDMAB were identified through GC/MS as leachable components in the aqueous 24‐h storage media. The effect of this elution explains the change in conversion measurements observed between dry and water‐stored conditions, which is more appropriately described as the “apparent” conversion. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009