Dental Materials
Volume 24, Issue 7 , Pages 901-907, July 2008

Benzoyl germanium derivatives as novel visible light photoinitiators for dental materials

  • Norbert Moszner

      Affiliations

    • Research & Development, Ivoclar Vivadent AG, FL-9494 Schaan, Liechtenstein
    • Corresponding Author InformationCorresponding author. Tel.: +423 2353429; fax: +423 2331279.
    • ,
  • Urs Karl Fischer

      Affiliations

    • Research & Development, Ivoclar Vivadent AG, FL-9494 Schaan, Liechtenstein
    • ,
  • Beate Ganster

      Affiliations

    • Vienna University of Technology, Institute of Applied Synthetic Chemistry, Getreidemarkt 9/163/MC, A-1060 Vienna, Austria
    • ,
  • Robert Liska

      Affiliations

    • Vienna University of Technology, Institute of Applied Synthetic Chemistry, Getreidemarkt 9/163/MC, A-1060 Vienna, Austria
    • ,
  • Volker Rheinberger

      Affiliations

    • Research & Development, Ivoclar Vivadent AG, FL-9494 Schaan, Liechtenstein

Received 18 September 2007; received in revised form 7 November 2007; accepted 8 November 2007.

Abstract 

Objectives

The objective of this study was to investigate the use of benzoyl germanium derivatives as a novel visible light photoinitiator of resin-based dental composites. Selected mechanical properties, such as flexural strength and flexural modulus, setting time, storage stability, and UV light stability, of the composites based on the novel photoinitiators benzoyltrimethylgermane (BTMGe) or dibenzoyldiethylgermane (DBDEGe) were investigated and compared to the properties of materials that are cured with a mixture of camphorquinone (CQ) and ethyl 4-(N,N-dimethylamino)benzoate (EMBO).

Methods

The flexural strength and flexural modulus of elasticity were determined according to ISO 4049. For this purpose, test specimens (2mm×2mm×25mm) of the composites investigated were prepared in stainless steel moulds and light-cured (150mW/cm2, 2s×180s). The flexural strength and flexural modulus of elasticity were measured after immersing the cured specimens in water for 24h at 37°C and in certain cases, after they had been boiled for 24h in water. In addition, the setting time, curing depth, storage and UV stability of selected composites were determined.

Results

The novel photoinitiators BTMGe or DBDEGe can be used to substitute the binary photoinitiator CQ/EMBO in visible light-cured restorative composites. Especially, DBDEGe showed a significantly higher photocuring activity in composites with a filler load of about 60wt. % in comparison to that of CQ/EMBO. In addition, composites based on BTMGe or DBDEGe showed an improved UV stability and a storage stability comparable to that of CQ/EMBO-based composites.

Keywords: Photopolymerization, Camphorquinone, Visible light photoinitiator, Composites, Dimethacrylates

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(07)00258-8

doi:10.1016/j.dental.2007.11.004

Dental Materials
Volume 24, Issue 7 , Pages 901-907, July 2008

Article Tools

* Image Usage & Resolution