The effect of powder/liquid mixing ratio on the stiffness and impact strength of autopolymerising dental acrylic resins.
The stiffness of representative cured autopolymerising dental acrylic resins was determined by calculation of a secant modulus from measurements in tension of load and extension, and related to the powder/liquid mixing ratio. The impact strengths of autopolymerising, heat-cure and commercial resins were compared. It was found that while the stiffness of autopolymerising resins was unaffected by variations in powder/liquid mixing ratio, extension to failure was greater with lower powder/liquid ratios. The impact strength of autopolymerising resins was found to be greater than that of heat-cure resins, and a tentative explanation is offered. These findings may help to explain the pattern of failure of acrylic resin denture bases.
Syme
V J
VJ
Sheffield School of Clinical Dentistry, Claremont Crescent, Sheffield, S10 2TA.
Lamb
D J
DJ
Lopattananon
N
N
Ellis
B
B
Jones
F R
FR
D000180:Acrylic Resins / Q000737:chemistry*; D000704:Analysis of Variance; D003764:Dental Materials / Q000737:chemistry*; D003819:Denture Bases; D004548:Elasticity; D006244:Hardness; D006358:Hot Temperature; D006801:Humans; D008422:Materials Testing; D008768:Methylmethacrylates / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D019904:Polymethyl Methacrylate / Q000737:chemistry; D011208:Powders; D012996:Solutions; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength
D000180:Acrylic Resins; D003764:Dental Materials; D008768:Methylmethacrylates; D011108:Polymers; D011208:Powders; C073910:Repair Material; D012996:Solutions; C029883:Trevalon universal; D019904:Polymethyl Methacrylate