Polymerization shrinkage of resin-based composites for dental restorations: A digital volume correlation study. Issue 11 (November 2019)

• Record Type: Journal Article
• Authors: Gallo, Marta; Abouelleil, Hazem; Chenal, Jean Marc; Adrien, Jérôme; Lachambre, Joël; Colon, Pierre; Maire, Eric
• Is Part Of: Dental materials. Volume 35:Issue 11(2019)
• Page Start: 1654
• Page End: 1664
• Publication Date: 2019-11
• Subjects: Polymerization shrinkage -- Adhesion -- Micro-tomography -- Digital volume correlation -- Strain -- In situ tests; Dentistry -- Periodicals; Dental materials -- Periodicals; 617.695
• DOI: 10.1016/j.dental.2019.08.116
• Languages: English
• ISSNs: 0109-5641

Abstract

Graphical abstract: Highlights: High resolution X-ray imaging of dental resins during in situ setting. Shrinkage is studied by micro-tomography coupled to digital volume correlation. DVC reveals differences between constrained and unconstrained setting. Adhesive at the interface does not reduce total shrinkage. Shrinkage occurs in the first 5 s of irradiation. Abstract: Objective: Resin-based composites are widely used in dental restorations; however, their volumetric shrinkage during polymerization leads to several issues that reduce the restoration survival rates. For overcoming this problem, a deep study of shrinkage phenomena is necessary. Methods: In this study, micro-tomography (μ-CT) is combined with digital volume correlation (DVC) to investigate the effect of several factors on the polymerization strain of dental composites in model cavities: the presence/absence of an adhesive, the use of transparent/blackened cavities, and irradiation times between 1 and 40 s. Results: The results indicate that the presence of an adhesive at the interface between the cavity and composite does not reduce the total strain but instead limits it to a preferential direction. In addition, regardless of the conditions, the main strain is generated along the axis parallel to the polymerization irradiation (the vertical axis). Finally, the total strain appears to occur in the first 5 s of irradiation, with no further evolution observed for longer irradiation times. Significance: This work provides new insight into resin-based composite shrinkage and demonstrates the benefit of coupling DVC and μ-CT to better understand the degradation mechanisms of these materials.