title: Effect of intrinsic pigmentation on the flexural strength of a microwave-cured acrylic resin.
abstract: This study investigated the effect of intrinsic pigmentation on the transverse strength of a microwave-cured acrylic resin. Forty transverse strength specimens were fabricated according to ADA specification #12 and divided into 5 groups. No fibers were added to group I (GI, control group); acrylic stain (AS) was added to GII and GIII in concentrations of 0.5 and 1.5% w/w, respectively; acrylic fibers (AF) were added to groups GIV and GV in concentrations of 0.5 and 1.5% w/w, respectively. All specimens were irradiated in a microwave oven with a cycle of 3 min at 360 W, followed by 4 min resting, then 3 min at 810 W. Flasks were bench-cooled for 30 min at room temperature, followed by immersion in cold tap water for 30 min. After storage in distilled water at 37 degrees C for 48 h, all specimens were tested for flexural strength in a testing machine (EMIC-DL 500) at a crosshead speed of 0.5 cm/min. Mean and standard deviation (MPa) for the flexural strength test were: GI = 86.0 +/- 7.9; GII = 86.0 +/- 9.8; GIII = 86.6 +/- 7.7; GIV = 84.9 +/- 5.3; GV = 84.9 +/- 5.2. No statistical differences were detected among the groups (ANOVA, p > 0.05). The addition of the acrylic fibers or the acrylic stain did not affect the transverse strength of the microwave-cured acrylic resin.
authors.affiliation: Department of Prosthodontics and Periodontology, Dental School of Piracicaba, UNICAMP, Piracicaba, SP, Brazil.
authors.forename: Frederico Augusto Peixoto
authors.initials: FA
authors.lastname: Silva
authors.forename: Tatiana Bernardon Peixoto
authors.initials: TB
authors.lastname: Silva
authors.forename: Rodrigo Nunes
authors.initials: RN
authors.lastname: Rached
authors.forename: Altair Antoninha
authors.initials: AA
authors.lastname: Del Bel Cury
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000704:Analysis of Variance; D003799:Dental Stress Analysis; D003819:Denture Bases; D003779:Denture Design / Q000379:methods*; D008422:Materials Testing; D008872:Microwaves; D018583:Pliability; D011108:Polymers / Q000737:chemistry; D017797:Prosthesis Coloring
chemical_list: D000180:Acrylic Resins; D011108:Polymers