universidade de são paulo - Faculdade de Odontologia - Unesp
universidade de são paulo - Faculdade de Odontologia - Unesp
universidade de são paulo - Faculdade de Odontologia - Unesp
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63<br />
mimicking the tissue-fitting surface and the outer surface of <strong>de</strong>ntures,<br />
respectively. The flasks were separated, silicone patterns removed, and the stone<br />
surfaces were painted with a separating medium (Vipi Film - VIPI Indústria e<br />
Comércio Exportação e Importação <strong>de</strong> Produtos Odontológicos Ltda<br />
Pirassununga, SP, Brazil). For each specimen, 1 g of pow<strong>de</strong>r and 0.47 ml of<br />
monomer liquid were mixed and processed according to the manufacturer’s<br />
instructions. The mixture was packed into the molds, a trial pack was completed,<br />
and excess material was removed. A final pack was performed and held for 15<br />
minutes. The <strong>de</strong>nture base acrylic resin was processed in a 500 W domestic<br />
microwave oven (Brastemp – Brastemp da Amazônia SA, Manaus, AM, Brazil)<br />
for 20 minutes at 20% power, followed by 5 minutes at 90% power. The flasks<br />
were allowed to bench cool at room temperature, the specimens were <strong>de</strong>flasked,<br />
and excess flash was aseptically removed with a sterile bur (Maxi-Cut; Lesfils <strong>de</strong><br />
August Malleifer SA, Ballaigues, Switzerland).<br />
Surface Roughness Measurements<br />
The surface roughness of all specimens was measured with a profilometer<br />
(Mitutoyo SJ 400 – Mitutoyo Corporation - Japan). Three measurements were<br />
ma<strong>de</strong> for each specimen and the average reading was <strong>de</strong>signated as the Ra (μm)<br />
value of that specimen. The resolution was 0.01 μm, the interval (cutoff length) of<br />
0.8 mm, the transverse length of 2.4 mm; the stylus speed 0.5 mm/s, and the<br />
diamond stylus tip radius was 5 μm. All measurements were recor<strong>de</strong>d by one<br />
operator.<br />
Plasma Treatments