Polymerization shrinkage stress of composite resins and resin cements - What do we need to know?

• Published in: Brazilian oral research Vol. 31; no. suppl 1; p. e62
• Main Authors: Soares, Carlos José, Faria-E-Silva, André Luis, Rodrigues, Monise de Paula, Vilela, Andomar Bruno Fernandes, Pfeifer, Carmem Silvia, Tantbirojn, Daranee, Versluis, Antheunis
• Format: Journal Article
• Language: English
• Published: Brazil Sociedade Brasileira de Pesquisa Odontológica - SBPqO 28-08-2017; Sociedade Brasileira de Pesquisa Odontológica
• Subjects: Composite Resins; Composite Resins - chemistry; Curing Lights, Dental; Dental Stress Analysis - instrumentation; Dental Stress Analysis - methods; Dentistry; DENTISTRY, ORAL SURGERY & MEDICINE; Materials Testing; Polymerization; Resin Cements - chemistry; Sensitivity and Specificity; Tooth; Composite Resins; Polymerization; Tooth; Sensitivity and Specificity
• ISSN: 1806-8324; 1807-3107; 1807-3107; 1806-8324
• DOI: 10.1590/1807-3107bor-2017.vol31.0062

Polymerization shrinkage stress of resin-based materials have been related to several unwanted clinical consequences, such as enamel crack propagation, cusp deflection, marginal and internal gaps, and decreased bond strength. Despite the absence of strong evidence relating polymerization shrinkage to secondary caries or fracture of posterior teeth, shrinkage stress has been associated with post-operative sensitivity and marginal stain. The latter is often erroneously used as a criterion for replacement of composite restorations. Therefore, an indirect correlation can emerge between shrinkage stress and the longevity of composite restorations or resin-bonded ceramic restorations. The relationship between shrinkage and stress can be best studied in laboratory experiments and a combination of various methodologies. The objective of this review article is to discuss the concept and consequences of polymerization shrinkage and shrinkage stress of composite resins and resin cements. Literature relating to polymerization shrinkage and shrinkage stress generation, research methodologies, and contributing factors are selected and reviewed. Clinical techniques that could reduce shrinkage stress and new developments on low-shrink dental materials are also discussed.