Y H Bağis1, F A Rueggeberg. 1. Department of Conservative Dentistry, University of Ankara School of Dentistry, Ankara, Turkey.
Abstract
OBJECTIVES: This research evaluated the relationship between post-cure heating temperature and duration on the monomer conversion of a commercial light-activated resin composite. METHODS: Disc-shaped composite specimens (10 x 1 mm) were initially light-cured and then submitted to one of the following post-cure. CONDITIONS: None (control), 50 degrees, 75 degrees, 100 degrees or 125 degrees C for 0.5, 1, 3, 5, or 7 min. After curing, specimens were stored in the dark at room temperature. Monomer conversion of all specimens was then determined using infrared spectroscopy. RESULTS: Post-cure temperature was 12 times more influential than was heal duration on the extent of resin cure. The extent of cure increased linearly with an increase in post-cure temperature. Post-cure specimens that were heated between 3 and 7 min demonstrated equivalent cure values. All post-cure healing conditions resulted in significantly higher cure values than the light-cured only control. SIGNIFICANCE: Physical properties of post-cure heated composites may change with respect to aging and water, but monomer conversion values of post-cure heated materials remain unaltered. Results of this study validate the use of relatively high temperatures for increasing the extent of monomer conversion. Such increases may lead to more biocompatible restorations.
OBJECTIVES: This research evaluated the relationship between post-cure heating temperature and duration on the monomer conversion of a commercial light-activated resin composite. METHODS: Disc-shaped composite specimens (10 x 1 mm) were initially light-cured and then submitted to one of the following post-cure. CONDITIONS: None (control), 50 degrees, 75 degrees, 100 degrees or 125 degrees C for 0.5, 1, 3, 5, or 7 min. After curing, specimens were stored in the dark at room temperature. Monomer conversion of all specimens was then determined using infrared spectroscopy. RESULTS: Post-cure temperature was 12 times more influential than was heal duration on the extent of resin cure. The extent of cure increased linearly with an increase in post-cure temperature. Post-cure specimens that were heated between 3 and 7 min demonstrated equivalent cure values. All post-cure healing conditions resulted in significantly higher cure values than the light-cured only control. SIGNIFICANCE: Physical properties of post-cure heated composites may change with respect to aging and water, but monomer conversion values of post-cure heated materials remain unaltered. Results of this study validate the use of relatively high temperatures for increasing the extent of monomer conversion. Such increases may lead to more biocompatible restorations.
Authors: Benjamin Howard; Nicholas D Wilson; Sheldon M Newman; Carmem S Pfeifer; Jeffrey W Stansbury Journal: Acta Biomater Date: 2009-11-12 Impact factor: 8.947
Authors: Renata A Esteves; Letícia C C Boaro; Flávia Gonçalves; Luiza M P Campos; Cecy M Silva; Leonardo Eloy Rodrigues-Filho Journal: Biomed Res Int Date: 2018-03-15 Impact factor: 3.411