title: Polymerization shrinkage of composite resins: comparison with tooth deformation.
abstract: Polymerization shrinkage of two posterior composite resin restorative materials was measured by dilatometry. The results were compared with a decrease in cavity width of MOD preparations in extracted premolars restored with the composite resins. A highly filled hybrid composite exhibited greater free shrinkage and cuspal deformation than a hybrid composite with a lower filler content. Deformation of the cusps was less than the unrestricted shrinkage of the composite resins. Hydrated teeth exhibited less deformation than dehydrated teeth because of polymerization shrinkage. Greater cuspal deformations were measured with the microscopic technique than with interferometry because of differences in experimental design.
authors.affiliation: Department of Conservative Dentistry, College of Dentistry, University of Mosul, Iraq.
authors.forename: A H
authors.initials: AH
authors.lastname: Suliman
authors.forename: D B
authors.initials: DB
authors.lastname: Boyer
authors.forename: R S
authors.initials: RS
authors.lastname: Lakes
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D017438:Bisphenol A-Glycidyl Methacrylate; D003188:Composite Resins / Q000737:chemistry*; D003737:Dental Cavity Preparation / Q000379:methods; D003793:Dental Restoration, Permanent; D004548:Elasticity; D006801:Humans; D007368:Interferometry; D008853:Microscopy; D011108:Polymers / Q000737:chemistry*; D011140:Polyurethanes / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D014070:Tooth / Q000648:ultrastructure*; D014867:Water
chemical_list: D000180:Acrylic Resins; C029012:Composite Dental Resin; D003188:Composite Resins; D011108:Polymers; D011140:Polyurethanes; D014867:Water; C065771:P50 composite resin; D017438:Bisphenol A-Glycidyl Methacrylate