Surface roughness of acrylic resins processed
\nby microwave energy and polished by mechanical and chemical process

Abstract

The aim of this study was to evaluate the influence of polymerization
\nmethods (microwave energy - MW, and water bath - WB) and polishing
\ntechniques (chemical - C and mechanical - M) on the surface roughness
\nof one heat-polymerized acylic resin (Vipi-Cril). Forty acrylic resin
\ndisk-shaped samples were made according to ADA specification n°
\n12. Half of samples were processed by microwave energy (500W for 3
\nminutes), and the other half by water bath (74±1 °C for 9
\nhours). After deflasking, the samples were trimmed with a sequence of
\nabrasive aluminum oxide sandpapers of different grades (180, 220 and
\n400) and divided in 4 groups according to polymerization methods and
\npolishing techniques: G1: MW+CP, G2: MW+MP, G3: WB+CP and G4: WB+MP.
\nSurface roughness values were measured using a Surfcorder SE 1700
\nrugosimeter (Kosaka Laboratory Ltd, Kosaka, Japan). Mann-Whitney test
\n(p=.05) indicated significant differences between polishing methods
\nprocessed by microwave energy (p= .0018), and between polishing methods
\nprocessing by water bath (p= .0002). Samples processed by both methods
\n(water bath or microwave energy) showed smoother surfaces when polished
\nby mechanical polishing method, and polymerization methods did not
\ninfluence in surface roughness.