title: Effect of phosphate-bonded investments on titanium reaction layer and crown fit.
abstract: This study analyzed the reaction layer and measured the marginal crown fit of cast titanium applied to different phosphate-bonded investments, prepared under the following conditions (liquid concentration/casting temperature): Rema Exakt (RE) - 100%/237 degrees C, 75%/287 degrees C, Castorit Super C (CS)-100%/70 degrees C, 75%/141 degrees C and Rematitan Plus (RP)- 100%/430 degrees C (special to titanium cast, as the control group). The reaction layer was studied using the Vickers hardness test, and analyzed by two way ANOVA and Tukey's HSD tests (alpha = 0.05). Digital photographs were taken of the crowns seated on the die, the misfit was measured using an image analysis system and One-way ANOVA, and Tukey's test was applied (alpha = 0.05). The hardness decreased from the surface (601.17 VHN) to 150 microm (204.03 VHN). The group CS 75%/141 degrees C presented higher hardness than the other groups, revealing higher surface contamination, but there were no differences among the groups at measurements deeper than 150 mum. The castings made with CS - 100%/70 degrees C presented the lowest levels of marginal misfit, followed by RE -100%/237 degrees C. The conventional investments CS (100%) and RE (100%) showed better marginal fit than RP, but the CS (75%) had higher surface contamination.
authors.affiliation: Department of Prevention and Oral Rehabilitation, Federal University of Goiás, Goiânia, Goiânia, GO, Brazil.
authors.forename: Sicknan Soares da
authors.initials: SS
authors.lastname: Rocha
authors.forename: Fabiane
authors.initials: F
authors.lastname: Nogueira
authors.forename: Anelise Rodolfo Ferreira
authors.initials: AR
authors.lastname: Pieralini
authors.forename: Ricardo Faria
authors.initials: RF
authors.lastname: Ribeiro
authors.forename: Gelson Luis
authors.initials: GL
authors.lastname: Adabo
mesh_terms: D000704:Analysis of Variance; D003442:Crowns; D003734:Dental Casting Investment / Q000737:chemistry*; D003735:Dental Casting Technique; D018772:Dental Marginal Adaptation; D003764:Dental Materials; D006245:Hardness Tests; D006358:Hot Temperature; D008422:Materials Testing; D010710:Phosphates / Q000737:chemistry*; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D003734:Dental Casting Investment; D003764:Dental Materials; D010710:Phosphates; D014025:Titanium