Development of low-shrinkage dental composites

Abstract

Dental composite resins have revolutionized modern clinical dentistry. They are widely used for restoring teeth and cosmetic dentistry due to their esthetic and handling properties. Despite their wide applications, present day composite resins shrink when cured. This polymerization shrinkage generate stresses which affect the marginal seal between the tooth/restoration interfaces leading to secondary caries, post-operative sensitivity, tooth fracture, bond failure and marginal leakage. Other problems associated with current dental composites include inadequate wear resistance and the leaching of uncured organic monomers. The development of low shrinkage resins is therefore an important research focus in dentistry and remains a challenge. In this review, different polymerization techniques such as soft-start, pulse cure and pulse delay used to minimize shrinkage clinically will be discussed. The effect of the different light-curing techniques on the crosslink density of composites will also be reported. Recent developments of low shrinkage composites including some of our work on silsesquioxane in the laboratory will also be highlighted. ©2011 Nova Science Publishers, Inc. All rights reserved.