Biomaterial Database

Polymerization contraction stress in light-cured compomer restorative materials. 2003

H Y Chen, and J Manhart, and K-H Kunzelmann, and R Hickel

Department of Restorative Dentistry, Dental School of the Ludwig--Maximilians-University, Goethe Street 70, Munich 80336, Germany. hchen@dent.med.uni-muenchen.de

OBJECTIVE The magnitude and kinetics of polymerization contraction stress build-up may be potential predictors of bond failure of adhesive restorations. The present study determined these properties of seven commercial compomers (Dyract, Dyract AP, F2000 Rasant, Hytac, Compoglass F, Luxat, Glasiosite). METHODS Polymerization shrinkage was generated by 40 s light curing the test materials (800 mW/cm2). The contraction force induced was recorded for 300 s at room temperature (23-24 degrees C) by means of a Stress-Strain-Analyzer (C factor=0.33). Maximum contraction stress (MPa), coefficient of near linear fit of contraction force/time (gradient) and relative force rate (%/s) of each material were compared with that of two hybrid composites (Tetric Ceram, Prodigy). The statistical analysis was conducted by ANOVA (alpha=0.05) and post hoc Tukey's test. RESULTS No statistically significant differences in the maximum stress between Glasiosite (2.27+/-0.06 MPa), Hytac (2.31+/-0.07 MPa) and Tetric Ceram (2.21+/-0.11 MPa), and between Compoglass F (2.60+/-0.18 MPa) and Prodigy (2.70+/-0.06 MPa) were found. The contraction stress of F2000 Rasant (3.41+/-0.09 MPa) and Luxat (3.33+/-0.08 MPa) were significantly highest, whilst Dyract exhibited the significantly lowest shrinkage stress (1.27+/-0.08 MPa) among the tested materials. CONCLUSIONS High contraction stress, early start of stress build-up and rapid contraction force development may lead to failure of bond to tooth structure. This study suggested that the contraction stress and kinetic behavior of compomers are generally similar to those of hybrid composites in a dry condition. Dyract might be superior in maintaining the bond with cavity walls compared to conventional hybrid composites in view of its low shrinkage stress.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008027	Light	That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.	Light, Visible,Photoradiation,Radiation, Visible,Visible Radiation,Photoradiations,Radiations, Visible,Visible Light,Visible Radiations
D011108	Polymers	Compounds formed by the joining of smaller, usually repeating, units linked by covalent bonds. These compounds often form large macromolecules (e.g., BIOPOLYMERS; PLASTICS).	Polymer
D003188	Composite Resins	Synthetic resins, containing an inert filler, that are widely used in dentistry.	Composite Resin,Resin, Composite,Resins, Composite
D003793	Dental Restoration, Permanent	A restoration designed to remain in service for not less than 20 to 30 years, usually made of gold casting, cohesive gold, or amalgam. (Jablonski, Dictionary of Dentistry, 1992)	Dental Fillings, Permanent,Dental Filling, Permanent,Dental Permanent Filling,Dental Permanent Fillings,Dental Restorations, Permanent,Filling, Dental Permanent,Filling, Permanent Dental,Fillings, Dental Permanent,Fillings, Permanent Dental,Permanent Dental Filling,Permanent Dental Fillings,Permanent Dental Restoration,Permanent Dental Restorations,Permanent Filling, Dental,Permanent Fillings, Dental,Restoration, Permanent Dental,Restorations, Permanent Dental
D003799	Dental Stress Analysis	The description and measurement of the various factors that produce physical stress upon dental restorations, prostheses, or appliances, materials associated with them, or the natural oral structures.	Analyses, Dental Stress,Analysis, Dental Stress,Stress Analyses, Dental,Stress Analysis, Dental,Dental Stress Analyses
D000704	Analysis of Variance	A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.	ANOVA,Analysis, Variance,Variance Analysis,Analyses, Variance,Variance Analyses
D013314	Stress, Mechanical	A purely physical condition which exists within any material because of strain or deformation by external forces or by non-uniform thermal expansion; expressed quantitatively in units of force per unit area.	Mechanical Stress,Mechanical Stresses,Stresses, Mechanical
D018772	Dental Marginal Adaptation	The degree of approximation or fit of filling material or dental prosthetic to the tooth surface. A close marginal adaptation and seal at the interface is important for successful dental restorations.	Adaptation, Marginal, Dental,Marginal Adaptation, Dental,Dental Internal Adaptation,Dental Internal Fit,Adaptation, Dental Internal,Adaptation, Dental Marginal,Adaptations, Dental Internal,Adaptations, Dental Marginal,Dental Internal Adaptations,Dental Internal Fits,Dental Marginal Adaptations,Fit, Dental Internal,Fits, Dental Internal,Internal Adaptation, Dental,Internal Adaptations, Dental,Internal Fit, Dental,Internal Fits, Dental,Marginal Adaptations, Dental
D020770	Compomers	Composite materials composed of an ion-leachable glass embedded in a polymeric matrix. They differ from GLASS IONOMER CEMENTS in that partially silanized glass particles are used to provide a direct bond to the resin matrix and the matrix is primarily formed by a light-activated, radical polymerization reaction.	Compomer,Composite Resins, Polyacid-Modified,Polyacid-Modified Composite Resin,Polyacid-Modified Composite Resins,Composite Resin, Polyacid-Modified,Composite Resins, Polyacid Modified,Polyacid Modified Composite Resin,Polyacid Modified Composite Resins,Resin, Polyacid-Modified Composite,Resins, Polyacid-Modified Composite