Effectiveness of self-adhesive luting cements in bonding to chlorhexidine-treated dentin.

Abstract

OBJECTIVES:

The aim was to investigate the microtensile bond strength (μ-TBS) and failure pattern of self-adhesive luting cements (SLC) to dentin pre-treated with different concentrations of chlorhexidine (CHX) solutions.

METHODS:

The occlusal enamel was removed from 30 extracted sound human molars in order to expose a flat dentin. Resin-composite (Filtek Z250, 3M ESPE) discs (12 mm in diameter, 6.0mm thickness) were cemented to the smear layer-covered dentin using the SLC [RelyX U100, 3M ESPE (U100); Multilink Sprint, Ivoclar Vivadent (MS)] with 0.2% or 2.0% CHX solutions. Results were compared with the control, untreated dentin. Six groups were then created based on the SLC and dentin pre-treatment (n=5). After 24h of water storage, restored teeth were serially sectioned into beams with a cross-sectional area of 0.8mm(2) at the bonded interface. Subsequently, specimens were tested in tension with a crosshead speed of 0.5mm/min in a universal testing machine, and the failure patterns were classified. Two-way ANOVA and Tukey's tests were performed (α=0.05). Additionally, 18 teeth were subjected to energy-dispersive X-ray spectroscopy (EDS) analysis and micromorphology characterization of the smear layer-covered dentin and 0.2% or 2.0% CHX-treated dentin surfaces.

RESULTS:

The μ-TBS obtained for both control groups were significantly higher, regardless of the CHX concentration and/or the cement used. Bond strengths were significantly higher for U100 than for MS, except when 2.0% CHX was applied. Fractographic analysis indicated that most failures in the control groups occurred cohesively in the SLC. Pre-treated dentin with 0.2% and 2.0% CHX solutions presented higher incidences of adhesive failures. EDS/SEM analysis exhibited varied concentrations of chlorine ions and crystal-shaped precipitates, depending upon the CHX concentration.

SIGNIFICANCE:

Pre-treatment of dentin with 0.2% or 2.0% CHX adversely affects the bonding efficacy when associated with the SLCs tested.

• Authors: Vinicius Di Hipólito, Flávia Pires Rodrigues, Fabiana Bárbara Piveta, Lídia da Cunha Azevedo, Roberta Caroline Bruschi Alonso, Nick Silikas, Ricardo Marins Carvalho, Mario Fernando De Goes, Paulo Henrique Perlatti D'Alpino
• Journal: Dental materials : official publication of the Academy of Dental Materials (Dent Mater) Vol. 28 Issue 5 Pg. 495-501 (May 2012) ISSN: 1879-0097 [Electronic] England
• PMID: 22204915 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Chemical References

• Anti-Infective Agents, Local
• Composite Resins
• Filtek Z250
• Resin Cements
• Silanes
• multilink adhesive system
• Water
• Aluminum Oxide
• Chlorhexidine

Topics

• Aluminum Oxide (chemistry)
• Anti-Infective Agents, Local (chemistry)
• Chlorhexidine (chemistry)
• Composite Resins (chemistry)
• Dental Bonding
• Dental Etching (methods)
• Dental Stress Analysis (instrumentation)
• Dentin (ultrastructure)
• Humans
• Materials Testing
• Microscopy, Electron, Scanning
• Resin Cements (chemistry)
• Silanes (chemistry)
• Smear Layer
• Spectrometry, X-Ray Emission
• Stress, Mechanical
• Surface Properties
• Temperature
• Tensile Strength
• Time Factors
• Water (chemistry)