Comparison of the accuracy of denture bases by a non‐parametric method

Abstract

A comparison of the accuracy of denture bases made from a conventional acrylic and four modified acrylic resins was made with the use of a non-parametric method. Twenty-five identical maxillary stone casts were made and five dentures for each resin were processed by conventional compression moulding techniques. The fit of each denture at the molar-to-molar region on its cast was evaluated by five evaluators who independently ranked the twenty-five dentures from best to worst fit after processing, after polishing, and after storage in water at 37 degrees C for 42 days. The ranking data were analysed by Kendall's coefficient of concordance, the Kruskal-Wallis statistic, and the Mann-Whitney test. Excellent agreement among observers was obtained. After storage in water, two modified acrylic resins, Hydrocryl and Vitalon II, had a better fit on their casts than the conventional acrylic, Lucitone Hypro. Luciton 199 had the same and Hircoe had a poorer fit than Lucitone Hypro.

Accuracy of adaptation of thermoformed poly(methyl methacrylate)

“…The space between the denture borders and the cast has been measured by various methods (Sanders, Levin & Reitz, 1991). These methods include a comparator (Rupp, Dickson & Lawson, 1957), a contourmeter (Ryge & Fairhurst, 1959), a non‐parametric method (Soni, Powers & Craig, 1979) and the use of feeler gauges (Sanders et al ., 1991).…”