Resumo

PAIVA, Carla Fernandes Rodrigues et al. Dimensional accuracy of impression material used in complete dentures. RGO, Rev. gaúch. odontol. (Online) [online]. 2012, vol.60, n.1, pp. 55-59. ISSN 1981-8637.

Objective The aim of this research was to compare the degree of dimensional stability and accuracy of Sapphire (Bosworth, Skokle, Illinois, EUA), which is an ethyl methacrylate acrylic resin, with polyvinyl siloxane (ADSIL-Vigodent, Rio de Janeiro, Brazil), a very accurate material of worldwide use. Methods The materials were tested by two techniques, the one-step putty and two-step putty-wash impression techniques. Stone casts were produced from impressions of an aluminum master cast of an edentulous maxilla. The samples were divided into four groups of 15 impressions each: Group 1 - putty-wash impression with Sapphire (putty) and Adsil Fluido (wash); Group 2 - putty impression with Sapphire; Group 3 - putty impression with Adsil Regular (putty); Group 4 - putty-wash impression with Adsil Regular (putty) and Adsil Fluido (wash). Measurements were done by the B251 Mitutoyo Coordinate Measuring Machine (Mitutoyo Co., Suzano, Brazil). The statistical treatment included calculating the mean, variance and standard deviation of the samples. The significance level was set at 5% (p<0.05). The distances found for each group were compared with those of the master cast by the t-test. Results Sapphire putty impressions presented the best dimensional stability. On the other hand, polyvinyl siloxane putty (Adsil) presented significant dimensional variations in samples produced from putty and putty-wash impressions. When Sapphire (Bosworth, Skokie, Illinois, EUA) and Adsil were used together (putty-wash), Sapphire (Bosworth, Skokie, Illinois, EUA) improved the results of the putty-wash impressions. Conclusion In conclusion, Sapphire (Bosworth, Skokie, Illinois, EUA) is a reliable and stable material that can be used for complete denture impressions.

Palavras-chave : Acrylic resins; Complete denture; Dental impression technique.