Long-term bond strength of a self-adhesive resin cement to intraradicular dentin pretreated with chlorhexidine and ethanol

Mariah Carvalho Guimarães Dos Santos,Roberta Tarkany Basting,Flávia Lucisano Botelho Amaral,Cecília Pedroso Turssi,Fabiana Mantovani Gomes França

doi:10.1590/1807-2577.01716

Mariah Carvalho Guimarães Dos Santos, Roberta Tarkany Basting + Show 3 more

Open Access

https://doi.org/10.1590/1807-2577.01716

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Abstract

Abstract Introduction Self-adhesive resin cements do not require prior preparation of the tooth surface, therefore dentin pretreatments may influence long-term bond strength. Objective To evaluate the influence of 100% ethanol (ET) and 2% chlorhexidine (CL) treatment of intraradicular dentin on the long-term bond strength (BS) of a self-adhesive resin cement (SRC). Material and method 80 bovine roots were restored with fiber posts and SRC (U200 3M/ESPE) and distributed into 4 groups according to dentin treatment: Group 1 – without treatment; Group 2 – 2% CL for 1 minute; Group 3 – 100% ET for 1 minute; Group 4 – 2% CL, followed by 100% ET. The samples were cross-sectioned to obtain two sections (0.7 mm) thick for each root third: coronal, middle and apical. The immediate push-out test was carried out after 48 hours, and the long-term push-out test, after 180 days. Result The three-way ANOVA test for randomized blocks showed no difference between the BS values at 48 hours and 80 days, irrespective of the treatment and the third (p>0.05). The interaction of the treatment/third pairing was significant (p = 0.041) since the treatment with CL promoted lower BS in the coronal third, while treatment with ET promoted better BS in the apical third. Conclusion Treatment with CL and ET, separately or combined, promoted no differences between the BS values of the SRC to root dentin over time.

Highlights

Self-adhesive resin cements do not require prior preparation of the tooth surface, dentin pretreatments may influence long-term bond strength
The exposed collagen fibrils, without the protection afforded by minerals, become susceptible to hydrolytic and enzymatic degradation mediated by matrix metalloproteinases (MMPs) that are exposed and activated during acid etching
Studies have evaluated the application of ethanol with the purpose of promoting the use of adhesive systems containing hydrophobic monomer units[11,17] and chlorhexidine as a MMP inhibitor[18]

Summary

INTRODUCTION

Extensive tooth loss may require root retention to ensure long-term retention and stability of coronal restorations, which can be achieved using intraradicular fiber posts[1,2]. The exposed collagen fibrils, without the protection afforded by minerals, become susceptible to hydrolytic and enzymatic degradation mediated by matrix metalloproteinases (MMPs) that are exposed and activated during acid etching This phenomenon allows continuous infiltration of a combination of fluids, bacterial metabolites and saliva MMPs that will result in degradation of the unprotected collagen fibrils in the lower portions of the hybrid layer. Studies have evaluated the application of ethanol with the purpose of promoting the use of adhesive systems containing hydrophobic monomer units[11,17] and chlorhexidine as a MMP inhibitor[18] It is still unclear, whether the combination of these two substances may act synergistically in the bonding of self-adhesive resin cements, in cases where the application of conventional adhesive systems is contraindicated. The null hypothesis tested was that the bonding durability of a dual-cure self-etching resin cement to root dentin in any root third would not be influenced by pretreatment with chlorhexidine or ethanol, after 48 hours and at 180 days

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CONCLUSION