Is the Polymerization Stress Produced During the Curing of Dental Composite Restorations Clinically Meaningful?
The application of light curing to cause the polymerization of a dental composite restoration produces a volumetric contraction within the material that creates stress on the surrounding tooth structure to which it is bonded. There is extensive evidence for the presence of this polymerization contraction stress in dental composites, as well as evidence for its deleterious effects, which include marginal leakage, gap formation, cusp deflection, tooth cracking, reduced bond strength and lowered mechanical properties of the restorative. The concern over these stresses and the manner in which they influence the placement of current composite materials demonstrates that they are considered to be very important. Manufacturers have spent considerable effort to develop lower shrinking or lower shrinkage stress composites, especially for use in bulk fill applications. But what evidence exists that these stresses actually have a direct effect on the clinical performance and longevity of dental composite restorations? The factors causing the stress, the methods proposed to minimize it, and the relation between contraction stress and clinical outcomes will be discussed.
This is lecture is free and open to the university public. For more information, please visit the College of Dentistry website: Distinguished Lecture Series