Effect of the addition of silanated silica on the mechanical properties of microwave heat-cured acrylic resin.
OBJECTIVE
The purpose of this study was to evaluate the flexural strength and Vickers hardness of a microwave energy heat-cured acrylic resin by adding different concentrations of silane surface-treated nanoparticle silica.


METHODS
Acrylic resin specimens with dimensions of 65 × 10 × 2.5 mm were formed and divided into five experimental groups (n = 10) according to the silica concentration added to the acrylic resin mass (weight %) prior to polymerisation : G1, without silica; G2, 0.1% silica; G3, 0.5% silica; G4, 1.0% silica; and G5, 5.0% silica. The specimens were submitted to a three-point flexural strength test and to the Vickers hardness test (HVN). The data obtained were statistically analysed by anova and the Tukey test (α = 0.05).


RESULTS
Regarding flexural strength, G5 differed from the other experimental groups (G1, G2, G3 and G4) presenting the lowest mean, while G4 presented a significantly higher mean, with the exception of group G3. Regarding Vickers hardness, a decrease in values was observed, in which G1 presented the highest hardness compared with the other experimental groups.


CONCLUSIONS
Incorporating surface-treated silica resulted in direct benefits in the flexural strength of the acrylic resin activated by microwave energy; however, similar results were not achieved for hardness.
Department of Dental Materials and Prosthodontics, Sao Jose dos Campos Dental School, Sao Paulo State University, UNESP, São José dos Campos, SP, Brazil. cdhian@gmail.com
Lucas H
LH
da Silva
Sabrina A
SA
Feitosa
Marcia C
MC
Valera
Maria A M
MA
de Araujo
Rubens N
RN
Tango
D000180:Acrylic Resins / Q000737:chemistry* / Q000528:radiation effects; D003764:Dental Materials / Q000737:chemistry* / Q000528:radiation effects; D003799:Dental Stress Analysis / Q000295:instrumentation; D005898:Glass / Q000737:chemistry / Q000528:radiation effects; D006244:Hardness; D006358:Hot Temperature; D006801:Humans; D008422:Materials Testing; D008872:Microwaves; D053758:Nanoparticles / Q000737:chemistry / Q000528:radiation effects; D018583:Pliability; D058105:Polymerization; D012821:Silanes / Q000737:chemistry* / Q000528:radiation effects; D012822:Silicon Dioxide / Q000737:chemistry* / Q000528:radiation effects; D013314:Stress, Mechanical; D013499:Surface Properties
D000180:Acrylic Resins; D003764:Dental Materials; D012821:Silanes; C009753:fiberglass; C539103:onda cryl; D012822:Silicon Dioxide; C040863:dichlorodimethylsilane