This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Braga, R.R. Articles by Ferracane, J.L. Search for Related Content PubMed PubMed Citation Articles by Braga, R.R. Articles by Ferracane, J.L. Social Bookmarking                         What's this?

Contraction Stress Related to Degree of Conversion and Reaction Kinetics

¹ Department of Dental Materials, University of São Paulo, School of Dentistry, Av. Prof. Lineu Prestes, 2227, São Paulo, SP, 05508-900, Brazil; and
² Department of Biomaterials and Biomechanics, Oregon Health & Science University, School of Dentistry, 611 SW Campus Drive, Portland, OR 97201, USA;

Correspondence: *corresponding author, OHSU, Biomaterials and Biomechanics Dept., School of Dentistry, 611 SW Campus Dr., Portland, OR 97201, USA, bragar{at}ohsu.edu

Polymerization shrinkage of composites bonded to cavity preparations generates stress on the tooth/restoration interface. The purpose of this study was to verify the influence of degree of conversion and speed of polymerization reaction on contraction stress. We prepared experimental composites with different curing rates by varying the concentration of inhibitor (butylated hydroxytoluene). We verified the effect of degree of conversion by submitting one of the composites to different photo-activation times. Contraction stress was monitored for 10 minutes in a tensilometer. Fourier-transformed infrared spectrometry was used for assessment of the degree of conversion. Volumetric shrinkage was determined by means of a mercury dilatometer. Degree of conversion and volumetric shrinkage showed a non-linear relationship with energy density. Degree of conversion showed a pronounced influence on stress. Increased inhibitor concentration reduced curing rate and contraction stress in composites, without compromising the final degree of conversion.

Key Words: composites • polymerization • contraction stress • volumetric shrinkage

Journal of Dental Research, Vol. 81, No. 2, 114-118 (2002)
DOI: 10.1177/154405910208100206


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				C.S. Pfeifer, J.L. Ferracane, R.L. Sakaguchi, and R.R. Braga Factors Affecting Photopolymerization Stress in Dental Composites Journal of Dental Research, November 1, 2008; 87(11): 1043 - 1047. [Abstract] [Full Text] [PDF]

				C. S. Costa Pfeifer, R. R. Braga, and P. E. C. Cardoso Influence of cavity dimensions, insertion technique and adhesive system on microleakage of Class V restorations J Am Dent Assoc, February 1, 2006; 137(2): 197 - 202. [Abstract] [Full Text] [PDF]

				J. M. Antonucci and D. Skrtic Matrix Resin Effects on Selected Physicochemical Properties of Amorphous Calcium Phosphate Composites Journal of Bioactive and Compatible Polymers, January 1, 2005; 20(1): 29 - 49. [Abstract] [PDF]

				R.R. Braga and J.L. Ferracane ALTERNATIVES IN POLYMERIZATION CONTRACTION STRESS MANAGEMENT Critical Reviews in Oral Biology & Medicine, May 1, 2004; 15(3): 176 - 184. [Abstract] [Full Text] [PDF]

				R. R. BRAGA, T. J. HILTON, and J. L. FERRACANE Contraction stress of flowable composite materials and their efficacy as stress-relieving layers J Am Dent Assoc, June 1, 2003; 134(6): 721 - 728. [Abstract] [Full Text] [PDF]