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Introduction: The purpose of this study was to investigate the effect of flask investment materials on the color changes of different brands of resin denture teeth. Methods: Resin denture teeth (560) were divided into 2 groups according to the materials used for flask investment (silicone or gypsum). All the specimens were thermocycled between 4°C and 60°C with 60-s dwell times for 1,000 cycles. Subsequently, the specimens of each group were divided into 4 subgroups based on the immersion media: coffee, tea, cola, and distilled water. Digital images of the teeth were taken before immersion and 30 days after immersion. The color samples were measured using the CIE L*a*b* system, and color differences (∆E) were calculated. The data were evaluated by three ways ANOVA and the Tukey HSD test. Results: There was not a significant difference in ∆E using three-way ANOVA, while the results showed considerable statistical differences with two factor ANOVA interaction. The ∆E values in the silicone group were significantly more than those in the gypsum group (P

Introduction: The purpose of this study was to investigate the effect of flask investment materials on the color changes of different brands of resin denture teeth. Methods: Resin denture teeth (560) were divided into 2 groups according to the materials used for flask investment (silicone or gypsum). All the specimens were thermocycled between 4°C and 60°C with 60-s dwell times for 1,000 cycles. Subsequently, the specimens of each group were divided into 4 subgroups based on the immersion media: coffee, tea, cola, and distilled water. Digital images of the teeth were taken before immersion and 30 days after immersion. The color samples were measured using the CIE L*a*b* system, and color differences (ΔE) were calculated. The data were evaluated by three ways ANOVA and the Tukey HSD test. Results: There was not a significant difference in ΔE using three-way ANOVA, while the results showed considerable statistical differences with two factor ANOVA interaction. The ΔE values in the silicone group were significantly more than those in the gypsum group (P<0.001). Among the solutions in which specimens were kept, maximum discoloration was seen with coffee followed by cola, tea, and distilled water. The Ivoclar Vivadent denture teeth in the silicone group, as well as the Apple teeth in the gypsum group exhibited the highest level of color stability. Conclusion: All test groups exhibited visually perceptible color changes; the denture teeth and flask investment materials, as well as the nutritional habits, significantly affected the color stability of the resin denture teeth. [ABSTRACT FROM AUTHOR]

Summary: Objectives: The objective of this study was to examine the two-body wear resistance of nine different resin denture teeth and one experimental material. Methods: The two-body wear test was performed in a chewing simulator with an antagonistic Al2O3 ball under an axial load of 40 N for 100,000 cycles. In each test series, an enamel sample was included as a reference. The wear was determined with an optical 3D surface profilometer. For statistical evaluation, SPSS for Windows was used. Results: The samples of Artiplus (18.7−SD 21.0) and e-Ha (21.2−SD 15.1) showed the lowest volumetric wear (in mm3×10−3) after 100,000 cycles. The difference from the other materials tested, except NC Veracia Posterior, was statistically significant (p=0.001−0.037). SR-Postaris-DCL (55.0−SD 6.8), SR-Orthosit-PE (61.1−SD 12.4) and Vitapan (72.1−SD 15.9) exhibited medium-sized wear values with low dispersion, whereas Orthognat (80.1−SD 31.6), Premium 8 (84.6−SD 31.4), NC Veracia Posterior (87.0−SD 52.7), SR-Orthotyp-PE (114.6−SD 28.0) and Trubyte Portrait (123.0−SD 45.6) showed high wear values with great variations. Statistically provable differences were found between SR-Orthotyp-PE and SR-Postaris-DCL (p=0.019) and also between SR-Orthotyp-PE and SR-Orthosit-PE (p=0.031). For enamel, a medium-sized wear value of 66.1−SD 76.8 was determined. Significance: The denture teeth examined showed differences in two-body wear resistance. The wear values determined were in some cases higher and in others lower than those of natural enamel. A definite connection between the wear resistance and the chemical composition of the materials could not be found in this investigation. [Copyright &y& Elsevier]