universidade de são paulo - Faculdade de Odontologia - Unesp

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Italy) measuring 13.8 X 2 mm were made. To obtain smooth and standardized
surfaces, the silicone patterns were invested in dental stone in microwave flasks
and positioned between two glass slides. After the stone had set, the flasks were
separated and the silicone patterns were removed. For each specimen, 1 g of
powder and 0.47 ml of monomer liquid were mixed, packed into the molds, and
processed in a 500 W domestic microwave oven (Brastemp – Brastemp da
Amazonia SA, Manaus, AM, Brazil) according to the manufacturer’s instructions
(20 minutes at 20% power, followed by 5 minutes at 90% power). The flasks were
allowed to bench cool at room temperature, the specimens were deflasked, and
excess flash was aseptically removed with a sterile bur (Maxi-Cut; Lesfils de
August Malleifer SA, Ballaigues, Switzerland).
Surface roughness measurements
The surface roughness of all specimens was measured with a profilometer
(Mitutoyo SJ 400 – Mitutoyo Corporation - Japan). Four measurements were
made for each specimen and the mean reading was designated as the Ra (μm)
value of that specimen. The measurements were recorded by one operator.
Resolution was 0.01 μm, interval (cutoff length) was 0.8 mm, transverse length
was 2.4 mm, the stylus speed was 0.5 mm/s, and the diamond stylus tip radius was
5 μm.
Saliva Collection
Whole human unstimulated saliva was collected from 15 healthy adult
volunteers. The saliva was expectorated into sterile 50 ml Falcon tubes on ice,