title: Relaxation modulus of denture base resin reinforced with woven glass fibers.
abstract: This study examined the reinforcing effect of woven glass fibers on the relaxation modulus by three-point loading of denture base resin. Three sandwich-type flexure test specimens polymerized by heating were used, all 3 mm thick: glass fibers in compression (U type); glass fibers in the center (C type); and glass fibers in tension (L type). Unreinforced specimens (ACR) were produced as a control. The relaxation modulus after 8 sec from the start of stress (Er(8)) was calculated from stress relaxation curves. In the glassy state, the Er(8)s of the U and L types were greater than those of the ACR and C types. In the rubbery state (plateau region), the Er(8)s of the U and L types were greater than those of the ACR and C types. The woven glass fibers added to the U and L type specimens increased the relaxation modulus of PMMA near the oral temperature; moreover, they inhibited stress relaxation when the temperature increased.
authors.affiliation: Department of Biomaterials Science, Kagoshima University Dental School, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan.
authors.forename: Takahito
authors.initials: T
authors.lastname: Kanie
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Arikawa
authors.forename: Koichi
authors.initials: K
authors.lastname: Fujii
mesh_terms: D000465:Algorithms; D000537:Aluminum Oxide / Q000737:chemistry; D000704:Analysis of Variance; D017609:Barium Compounds / Q000737:chemistry; D017610:Calcium Compounds / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry*; D003819:Denture Bases; D004548:Elasticity; D005898:Glass / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D010087:Oxides / Q000737:chemistry; D018583:Pliability; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D019279:Resin Cements / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013223:Statistics as Topic; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D014783:Viscosity
chemical_list: D017609:Barium Compounds; D017610:Calcium Compounds; D003764:Dental Materials; D008689:Methacrylates; D010087:Oxides; D019279:Resin Cements; D012821:Silanes; C009753:fiberglass; C017492:methacryloxypropyltrimethoxysilane; D012822:Silicon Dioxide; C077606:barium oxide; D019904:Polymethyl Methacrylate; C016538:lime; D000537:Aluminum Oxide