Dental Materials
Volume 22, Issue 10 , Pages 934-941, October 2006

Chemical analysis and bonding reaction of RelyX Unicem and Bifix composites—A comparative study

  • Hans U.V. Gerth

      Affiliations

    • Institute of Physical Chemistry, University of Münster, Germany
    • ,
  • Till Dammaschke

      Affiliations

    • Department of Operative Dentistry, University of Münster, Poliklinik für Zahnerhaltung, Waldeyerstr. 30, D-48149 Münster, Germany
    • Corresponding Author InformationCorresponding author. Tel.: +49 251 8347035; fax: +49 251 8347037.
    • ,
  • Harald Züchner

      Affiliations

    • Institute of Physical Chemistry, University of Münster, Germany
    • ,
  • Edgar Schäfer

      Affiliations

    • Department of Operative Dentistry, University of Münster, Poliklinik für Zahnerhaltung, Waldeyerstr. 30, D-48149 Münster, Germany

Received 8 June 2005; received in revised form 29 September 2005; accepted 27 October 2005.

Abstract 

Objectives

The chemical and physical properties of the dual curing luting composites RelyX Unicem (3M ESPE) and Bifix (VOCO) were analyzed with regard to their elemental composition, surface morphology and polymerization reaction. The bonding of both materials to hydroxyapatite (HAp) was studied.

Methods

The main components were analyzed by XPS and EDX. The minor components were identified with ICP-OES. Moreover, the morphology was examined by SEM and the polymerization reaction products were investigated using GPC. XPS was also applied to study the bonding mechanisms to HAp.

Results

The inorganic product particles consist of an Al–Si–Na-glass network, which incorporates radiopaque strontium and barium for Bifix and strontium and lanthanum for RelyX Unicem. RelyX Unicem contains about 10% fluoride and 2% Ca(OH)2, whereas Bifix comprises 2% fluoride. After polymerization, reaction products of 105–106g/mol were identified with RelyX Unicem. Both products contain mono- and oligomeric compounds. The reaction with HAp generates calcium atoms with a reduced binding energy. They act as an electron acceptor and show chemical interaction between the composite and HAp. With RelyX Unicem 86% of the calcium atoms reacted, compared to 65% with Bifix.

Significance

The intense chemical interaction of RelyX Unicem with HAp seems to be relevant to clinical aspects and explains the mechanical product properties. After setting, a polymer was found with RelyX Unicem but only monomeric/oligomeric products were identified at the surface of Bifix.

Keywords: Adhesion, Composite, EDX, GPC, Resin, SEM, XPS

To access this article, please choose from the options below

Login to an existing account or Register a new account.

  • Purchase this article for 31.50 USD (You must login/register to purchase this article)

    Online access for 24 hours. The PDF version can be downloaded as your permanent record.

  • Subscribe to this title

    Get unlimited online access to this article and all other articles in this title 24/7 for one year.

  • Claim access now

    For current subscribers with Society Membership or Account Number.

  • Visit SciVerse ScienceDirect to see if you have access via your institution.
 

PII: S0109-5641(05)00308-8

doi:10.1016/j.dental.2005.10.004

Dental Materials
Volume 22, Issue 10 , Pages 934-941, October 2006

Article Tools

* Image Usage & Resolution