Chlorhexidine stabilizes the adhesive interface: A 2-year in vitro study

Breschi, Lorenzo; Mazzoni, Annalisa; Nato, Fernando; Carrilho, Marcela; Visintini, Erika; Tjäderhane, Leo; Ruggeri, Alessandra; Tay, Franklin R.; Dorigo, Elettra De Stefano; Pashley, David H.

doi:10.1016/j.dental.2009.11.153

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Volume 26, Issue 4 , Pages 320-325, April 2010

Chlorhexidine stabilizes the adhesive interface: A 2-year in vitro study

Lorenzo Breschi
- Department of Biomedicine, Unit of Dental Sciences and Biomaterials, University of Trieste, Trieste, Italy
- IGM-CNR, Unit of Bologna c/o IOR, Bologna, Italy
- Corresponding author at: Department of Biomedicine, Unit of Dental Sciences and Biomaterials, University of Trieste, Via Stuparich 1, I-34129 Trieste, Italy. Tel.: +39 040 3992192; fax: +39 040 3992665.
Annalisa Mazzoni
- Department of SAU&FAL, University of Bologna, Bologna, Italy
Fernando Nato
- Department of SAU&FAL, University of Bologna, Bologna, Italy
- Department of SUAN, University “Carlo Bo”, Urbino, Italy
Marcela Carrilho
- Department of Restorative Dentistry, Piracicaba School of Dentistry, University of Campinas, Piracicaba, Brazil
- Bandeirante University of São Paulo (UNIBAN), São Paulo, Brazil
Erika Visintini
- Department of Biomedicine, Unit of Dental Sciences and Biomaterials, University of Trieste, Trieste, Italy
Leo Tjäderhane
- Institute of Dentistry, University of Oulu and Oulu University Hospital (OUH), Oulu, Finland
Alessandra Ruggeri Jr
- Department of SAU&FAL, University of Bologna, Bologna, Italy
Franklin R. Tay
- Department of Oral Biology and Maxillofacial Pathology, School of Dentistry, Medical College of Georgia, Augusta, GA, USA
Elettra De Stefano Dorigo
- Department of Biomedicine, Unit of Dental Sciences and Biomaterials, University of Trieste, Trieste, Italy
David H. Pashley
- Department of Oral Biology and Maxillofacial Pathology, School of Dentistry, Medical College of Georgia, Augusta, GA, USA

Received 2 July 2009; accepted 24 November 2009.

Abstract

Objectives

This study evaluated the role of endogenous dentin MMPs in auto-degradation of collagen fibrils within adhesive-bonded interfaces. The null hypotheses tested were that adhesive blends or chlorhexidine digluconate (CHX) application does not modify dentin MMPs activity and that CHX used as therapeutic primer does not improve the stability of adhesive interfaces over time.

Methods

Zymograms of protein extracts from human dentin powder incubated with Adper Scotchbond 1XT (SB1XT) on untreated or 0.2–2% CHX-treated dentin were obtained to assay dentin MMPs activity. Microtensile bond strength and interfacial nanoleakage expression of SB1XT bonded interfaces (with or without CHX pre-treatment for 30s on the etched surface) were analyzed immediately and after 2 years of storage in artificial saliva at 37°C.

Results

Zymograms showed that application of SB1XT to human dentin powder increases MMP-2 activity, while CHX pre-treatment inhibited all dentin gelatinolytic activity, irrespective from the tested concentration. CHX significantly lowered the loss of bond strength and nanoleakage seen in acid-etched resin-bonded dentin artificially aged for 2 years.

Significance

The study demonstrates the active role of SB1XT in dentin MMP-2 activation and the efficacy of CHX inhibition of MMPs even if used at low concentration (0.2%).

Keywords: Chlorhexidine, Dental bonding systems, Hybrid layer, Aging, Dentin