Assessment of superficial rugosity of cast titanium in fluoride solutions and artificial salive

Abstract

ride dental solution, by means of an analysis of superficial rugosity. In addition, scanning electron microscopy (SEM) was employed to observe the surface morphology after the test. Materials and Methods Specimen preparation and test solutionsCylindrical specimen (20 mm x 5 mm, n = 5) consisting of commercially pure titanium ASTM ® /grade 2 (Ti2 -Dentaurum J.P. Winkelstroeter KG-Pforzheim, Germany) were casted in the Rematitan system (Rematitan, Dentaurum J.P. Winkerstroeter KG, Pforzheim, Germany) by Vaiazzi Dental Laboratory (São Paulo -SP, Brazil). All specimens were cold mounted with epoxy resin and then received the standard metallography procedure for titanium. The specimens were mechanically polished on wet SiC paper grade 100-1000 (Strues, Denmark), and on successively finer grades of diamond paste 6, 3 and 1 μm (Strues, Denmark). Exposed surface areas of the specimens were 90 to 100 mm 2 . They were then degreased in ethanol and rinsed with distilled water. The polished surfaces were examined by optical microscopy (BX600, Olympus ® ) before fluoride attack. All test solutions were prepared by Mil Fórmulas pharmacy (Rio de Janeiro -RJ, Brazil). The specimens (n = 5) were divided into 5 groups (one for each group) of different tested solutions: Group 1) synthetic saliva with pH 7.0 (control); Group 2) 1.23% acidulated phosphate fluoride (APF) gel with pH 3.5; Group 3) 2% NaF gel with pH 6.5; Group 4) 0.05% NaF solution with pH 4.0; and Group 5) 0.05% NaF solution with pH 7.5. The specimens were exposed to these solutions for 16 minutes. To simulate an intra oral condition, after attack the specimens were immersed in synthetic saliva waved for 96 hours in magnetic stirrer. The purpose of this study was to investigate the superficial rugosity of commercially pure titanium cast, under the action of different fluoride dental solutions and synthetic saliva. All specimens received the standard metallography procedure for titanium and were divided in groups: Group 1) synthetic saliva pH 7.0; Group 2) 1.23% APF gel pH 3.5;, Group 3) 2% NaF gel pH 6; Group 4) 0.05% NaF solution pH 4.0; and Group 5) 0.05% NaF solution pH 7.5. The specimens were exposed to these solutions for 16 minutes and immersed in synthetic saliva for 96 hours. The surfaces were analyzed in a roughness device and the results were statistically treated -Snededor 'F' and Bonferroni test. In addition, scanning electron microscopy was employed to observe the surface morphology after the test. The Group 2 was the only one which had a significant increase in the superficial roughness. Authors concluded that the fluoride solutions of dental use that have a high concentration of fluoride and low pH are harmful to the surface of cast titanium.