Flexural properties of repaired heat-polymerising acrylic resin after wetting with monomer and acetone.
OBJECTIVE
Repair strength can be improved by treating fractured surfaces of a denture.


BACKGROUND
This study investigated flexural properties of heat-polymerised acrylic resin specimens repaired with auto-polymerising and visible light curing (VLC) resins after the repair surfaces were wetted with monomers or acetone.


METHODS
Fifty-four specimens (65 x 10 x 2.5 mm) were prepared and 48 of them were sectioned to simulate denture fracture. Butt-joint designed repair surfaces were wetted with heat-, auto-polymerising monomers and acetone for 180 s and repaired with auto-polymerising and VLC resins. After repairs, specimens were subjected to three-point bending test and flexural strength, strain, fracture load, modulus of elasticity and deflection values were recorded. Data were analysed with Student t and LSD tests (p < or = 0.05).


RESULTS
Overall flexural strength, strain, fracture load and deflection values of specimens repaired with VLC resin were significantly higher than the specimens repaired with auto-polymerising resin for all types of wetting agent (p < 0.05). Within the wetting agents, heat- and auto-polymerising monomers produced the best mechanical properties, while wetting with acetone did not provide superior effect over both monomers.


CONCLUSIONS
In clinical use, wetting the repair surfaces may result in stronger repairs. The use of bonding agent in VLC resin repairs in combination with wetting agent results in improved flexural properties.
Bural
Canan
C
Department of Removable Prosthodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey. cbural@istanbul.edu.tr
Bayraktar
Gülsen
G
Aydin
Ismail
I
Yusufoğlu
Ibrahim
I
Uyumaz
Natuk
N
Hanzade
Mete
M
D000096:Acetone / Q000737:chemistry*; D000180:Acrylic Resins / Q000737:chemistry*; D001840:Dental Bonding / Q000379:methods; D003764:Dental Materials / Q000737:chemistry*; D003799:Dental Stress Analysis / Q000295:instrumentation; D003819:Denture Bases; D003780:Denture Repair; D055119:Elastic Modulus; D004548:Elasticity; D006358:Hot Temperature; D006801:Humans; D008422:Materials Testing; D020366:Methylmethacrylate / Q000737:chemistry; D018583:Pliability; D058105:Polymerization; D012997:Solvents / Q000737:chemistry*; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors; D017155:Wettability
D000180:Acrylic Resins; D003764:Dental Materials; D012997:Solvents; C060386:Triad resin; D000096:Acetone; D020366:Methylmethacrylate