title: Softening patterns of post-cure heat-treated dental composites.
abstract: The softening of post-cure, heat-treated dental composites in various solutions was evaluated by Knoop hardness measurements. The samples were heated at 120 degrees C for 7 min immediately after curing and immersed in various solutions, water, ethanol, heptane and 0.1 N NaOH. Significant increases in hardness were observed for heated samples when compared to unheated samples. The various solutions softened both heated and unheated composites but heated samples were softened to a lesser degree. Plots of hardness of heated and unheated samples were nearly parallel, indicating that mechanisms such as penetration of the resin matrix, degradation of the silane coupling agent and fillers may be involved in the softening of both heated and unheated composites. Post-cure heat treatment improved the resistance to softening of dental composites.
authors.affiliation: Department of Restorative Dentistry, School of Dental Medicine, University of Pennsylvania, Philadelphia.
authors.forename: F
authors.initials: F
authors.lastname: Mante
authors.forename: N
authors.initials: N
authors.lastname: Saleh
authors.forename: M
authors.initials: M
authors.lastname: Mante
mesh_terms: D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D000431:Ethanol / Q000737:chemistry; D006244:Hardness; D006536:Heptanes / Q000737:chemistry; D006358:Hot Temperature; D008422:Materials Testing; D019279:Resin Cements; D012972:Sodium Hydroxide / Q000737:chemistry; D014520:Urethane / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: C075707:Brilliant Enamel; D003188:Composite Resins; D006536:Heptanes; C079764:Pertac hybrid; D019279:Resin Cements; C090922:True Vitality; D014867:Water; C056413:Occlusin; C065770:Herculite XR; C073466:Prisma APH; D014520:Urethane; D000431:Ethanol; D017438:Bisphenol A-Glycidyl Methacrylate; D012972:Sodium Hydroxide; C067318:P10 dental resin; C069717:Viso-Fil