Resumo

HIRAMATSU, Daniel Afonso et al. Roughness and porosity of provisional crowns. RPG, Rev. pós-grad. [online]. 2011, vol.18, n.2, pp. 108-112. ISSN 0104-5695.

This study aimed at evaluating the surface roughness and porosity of an acrylic resin used for provisional crowns. Six different processing techniques (direct and indirect) were assessed: (I) heat-cured acrylic resin under pressure; (II) heat-aided autopolymerizing resin under pressure; (III) autopolymerizing resin under pressure; (IV) bead-brush technique; (V) autopolymerizing resin in sandy stage; (VI) autopolymerizing resin in plastic stage. Twelve specimens were made for each test group. Roughness was evaluated with a rugosimeter, and pore quantification was performed using a stereoscopic magnifying lens. The highest mean surface roughness (Ra = 0.908 mm) was measured for Group VI. The lowest surface roughness value (Ra = 0.141 mm) was determined for Group I. Significant differences in mean surface roughness were found between direct and indirect techniques. Direct techniques reached the highest roughness and porosity values; its use should be restricted to avoid creating favorable conditions for microorganism proliferation.

Palavras-chave : Dental restoration, temporary; Tooth crown; Dental prosthesis.