1. Chlorhexidine preserves the hybrid layer in vitro after 10-years aging.
- Author
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Breschi L, Maravic T, Comba A, Cunha SR, Loguercio AD, Reis A, Hass V, Cadenaro M, Mancuso E, Mayer-Santos E, Niu L, Pashley DH, Tay FR, and Mazzoni A
- Subjects
- Composite Resins, Dentin, Dentin-Bonding Agents, Materials Testing, Resin Cements, Tensile Strength, Chlorhexidine pharmacology, Dental Bonding
- Abstract
Objective: The present study investigated the ability of a chlorhexidine (CHX)-containing primer (0.2% aqueous solution) to inhibit dentinal enzymes, preserve the hybrid layer (HL) and remain within the HL, after 10 years of aging in artificial saliva at 37°C., Methods: Non-carious extracted molars were assigned to two groups, cut into slabs exposing middle/deep dentin, etched and bonded with Adper Scotchbond 1XT (SB1XT) with or without 0.2% CHX aqueous solution pretreatment. Composite build-ups were made, and the specimens were cut in 1-mm thick bonded sticks. In situ zymography was performed on freshly prepared specimens (T
0 ) and specimens aged for 10 years (T10-yr ) at 37°C in artificial saliva, to investigate endogenous gelatinolytic activity within the HL. At T10-yr , specimens were also decalcified and embedded in epoxy resin for TEM analysis. Micro-Raman spectroscopy was performed at T0 and T10-yr to evaluate the chemical profiles in intertubular dentin and the HL., Results: In situ zymography showed less pronounced enzymatic activity in the CHX-pretreated group (p<0.05) regardless of aging, maintaining a similar level of fluorescence at T0 and T10-yr (p>0.05). TEM results showed that 98% of the HL had been degraded in the control group, while 95% of the HL was intact in the experimental group. Moreover, all the Raman spectra peaks assigned to CHX could be identified only in the CHX-pretreated group (T0 and T10-yr )., Significance: In vitro, CHX remains in the HL after 10 years with its inhibitory effect preserved. This may be the underlying factor for HL preservation after this long aging period., (Copyright © 2020 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.)- Published
- 2020
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