Flexural properties of denture base polymers reinforced with a glass cloth-urethane polymer composite.
OBJECTIVE
A newly designed light-cured reinforcement made from urethanemethacrylate oligomer and woven glass cloth has orthotropic anisotropy. This is produced for incorporation into the outermost position under the greatest tension in denture base resins. In this study, the flexural properties of self-, heat-, and light-curing reinforced resins were determined.


METHODS
The silanized glass cloth was soaked in urethanemethacrylate oligomer containing camphorquinone and 2-(dimethylamino)ethylmethacrylate. It was sandwiched between two pieces of polyethylene film and pressed to form a reinforcement sheet 0.3 mm in thickness, which was light-cured and prepared using four different surface conditions: with or without the polyethylene film and with or without a bonding agent. The reinforcement sheet was fixed in a fluorocarbon resin mold 3 mm in thickness, which was filled with self-, heat-, or light-curing resin and cured. The cured laminated plate was cut for flexural testing (40 x 7 x 3 mm3). A three-point flexural test was carried out at a crosshead speed of 2 mm/min and a span length of 30 mm. In this study, the glass fiber content was measured at percentages by weight because it was not possible to determine accurately the volume of the various polymers.


RESULTS
The baseline flexural strengths of the self-, heat-, and light-curing resins were 76.2, 68.6, and 55.6 MPa, respectively, and these values were increased to 271.7, 216.4, and 266.5 MPa by the reinforcement sheet. The baseline flexural moduli of self-, heat-, and light-curing resins were 2.0, 2.4, and 2.1 GPa, respectively. These values were increased to 7.2, 5.1, and 6.6 GPa by the reinforcement sheet. SEM photographs revealed good impregnation of the glass fiber within the polymer matrix.


CONCLUSIONS
The differences in the flexural strengths and flexural moduli of the control and reinforced specimens were significant (p < 0.01).
Department of Biomaterials Science, Kagoshima University Graduate School of Medical and Dental Sciences, Sakuragaoka, Kagoshima 890-8544, Japan. einak@dentb.hal.kagoshima-u.ac.jp
Takahito
T
Kanie
Hiroyuki
H
Arikawa
Koichi
K
Fujii
Seiji
S
Ban
D003188:Composite Resins / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D003819:Denture Bases; D005898:Glass / Q000737:chemistry*; D006358:Hot Temperature; D006801:Humans; D008027:Light; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D018583:Pliability; D011095:Polyethylenes / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D011140:Polyurethanes / Q000737:chemistry*; D019163:Reducing Agents / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013729:Terpenes / Q000737:chemistry
D003188:Composite Resins; D003764:Dental Materials; D008689:Methacrylates; D011095:Polyethylenes; D011108:Polymers; D011140:Polyurethanes; D019163:Reducing Agents; D012821:Silanes; D013729:Terpenes; C009753:fiberglass; C029824:urethane dimethacrylate luting resin; C048339:camphoroquinone; C049840:2-(dimethylamino)ethyl methacrylate