title: Comparison between a silorane-based composite and methacrylate-based composites: shrinkage characteristics, thermal properties, gel point and vitrification point.
abstract: A silorane-based composite was compared against methacrylate-based composites in terms of shrinkage characteristics, thermal properties, gel point, and vitrification point. Shrinkage strain was measured using a laser triangulation method. Shrinkage stress was measured using a stress analyzer. Heat flow during photopolymerization was measured using photo-DSC. Statistical analysis was performed using one-way ANOVA and Tukey's test (p=0.05). Silorane exhibited significantly lower shrinkage strain than the methacrylate-based composites.  It also presented the lowest stress values during light exposure, but the highest maximum stress rate after light exposure. It showed the highest heat flow rate, and it took the longest time to reach gel and vitrification points. Silorane demonstrated improved performance over the methacrylate-based composites with delayed gel and vitrification points as well as reduced shrinkage strain and stress. However, a high quantity of heat was liberated during the curing process, causing silorane to show significantly higher stress rate (p<0.05) than the methacrylate-based composites after light exposure.
authors.affiliation: Department of Dental Materials, Peking University School and Hospital of Stomatology, 22 Zhongguanchun South Road, HaiDian District, Beijing 100081, China.
authors.forename: Bo-Tao
authors.initials: BT
authors.lastname: Gao
authors.forename: Hong
authors.initials: H
authors.lastname: Lin
authors.forename: Gang
authors.initials: G
authors.lastname: Zheng
authors.forename: Yong-Xiang
authors.initials: YX
authors.lastname: Xu
authors.forename: Jin-Liang
authors.initials: JL
authors.lastname: Yang
mesh_terms: D002152:Calorimetry, Differential Scanning; D003188:Composite Resins / Q000737:chemistry* / Q000528:radiation effects; D055117:Curing Lights, Dental; D003799:Dental Stress Analysis / Q000295:instrumentation; D055119:Elastic Modulus; D006358:Hot Temperature; D006801:Humans; D007834:Lasers; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry* / Q000528:radiation effects; D044367:Phase Transition; D055668:Photochemical Processes; D058105:Polymerization; D062047:Silorane Resins; D012833:Siloxanes / Q000737:chemistry* / Q000528:radiation effects; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013814:Thermal Conductivity; D013997:Time Factors
chemical_list: D003188:Composite Resins; C444701:Filtek Z250; D008689:Methacrylates; D062047:Silorane Resins; D012833:Siloxanes; C488393:Venus (composite resin); C544925:filtek P90; C555513:silorane composite resin; C039734:Durafill