Journal of Conservative Dentistry

ORIGINAL ARTICLE
Year
: 2012  |  Volume : 15  |  Issue : 3  |  Page : 237--241

Evaluation of Vickers hardness and depth of cure of six composite resins photo-activated with different polymerization modes


C Poggio, M Lombardini, S Gaviati, M Chiesa 
 Department of Operative Dentistry, University of Pavia, Policlinico "San Matteo", Piazzale Golgi 2, 27100 Pavia, Italy

Correspondence Address:
C Poggio
Department of Operative Dentistry, University of Pavia, Policlinico DQSan MatteoDQ, Piazzale Golgi 2, 27100, Pavia
Italy

Aim: The current in vitro study evaluated Vickers hardness (VK) and depth of cure (hardness ratio) of six resin composites, polymerized with a light-emitting diode (LED) curing unit by different polymerization modes: Standard 20 s, Standard 40 s, Soft-start 40 s. Materials and Methods: Six resin composites were selected for the present study: three microhybrid (Esthet.X HD, Amaris, Filtek Silorane), two nanohybrid (Grandio, Ceram.X mono) and one nanofilled (Filtek Supreme XT). The VK of the surface was determined with a microhardness tester using a Vickers diamond indenter and a 200 g load applied for 15 seconds. The mean VK and hardness ratio of the specimens were calculated using the formula: hardness ratio = VK of bottom surface / VK of top surface. Results: For all the materials tested and with all the polymerization modes, hardness ratio was higher than the minimum value indicated in literature in order to consider the bottom surface as adequately cured (0.80). Curing time did not affect hardness ratio values for Filtek Silorane, Grandio and Filtek Supreme XT. Conclusion: The effectiveness of cure at the top and bottom surface was not affected by Soft-start polymerization mode.


How to cite this article:
Poggio C, Lombardini M, Gaviati S, Chiesa M. Evaluation of Vickers hardness and depth of cure of six composite resins photo-activated with different polymerization modes.J Conserv Dent 2012;15:237-241


How to cite this URL:
Poggio C, Lombardini M, Gaviati S, Chiesa M. Evaluation of Vickers hardness and depth of cure of six composite resins photo-activated with different polymerization modes. J Conserv Dent [serial online] 2012 [cited 2020 Jul 9 ];15:237-241
Available from: http://www.jcd.org.in/article.asp?issn=0972-0707;year=2012;volume=15;issue=3;spage=237;epage=241;aulast=Poggio;type=0