Analysis of elements released from base metal alloys used in prosthodontics

Abstract

The objective of the research was to analyse the types and amounts of elements released from eight unpolished and polished base metal casting dental alloys used in Prosthodontics. The differences in corrosion resistance among alloys in both unpolished and polished groups were assessed. The differences in the amounts of elements released between unpolished and polished alloys were compared. Eight base metal alloys were cast into a cubic shape measuring 3x7x8 mm. There were six specimens in each group (n=6). Each specimen was ultrasonically cleaned in ethanol and non-ionized distilled water, then immersed in plastic centrifugal tube with lactic acid/NaCl solution and maintained at 37 ํC for 336 hours. The ratio of the specimen surface area to volume of solution was 0.60 cm[superscript 2]/ml. Specimens were then removed and the concentration of the elements released in the solution was analyzed using the inductive coupled plasma optical emission spectrophotometer (ICP-OES). The one-way analysis of variance (ANOVA) and the independent sample t-test method were used to analyze with 95% confidence interval ([alpha] = 0.05). The amount of elements released ranged from 15.25 to 503.42 [microgram]/cm[superscript 2] in the polished groups and from 23.22 to 2, 426.82 [microgram]/cm[superscript 2] in the unpolished groups. The elements released were not proportionate to the bulk alloys' nominal composition. There were statistically significant differences in the total elements released among eight alloys in both unpolished and polished group (p<0.001) Alloys composed with a high chromium component were likely to show a higher resistance to corrosion. Polished alloys released significantly less amounts of elements than unpolished alloys (p<0.05). In conclusion, the polishing procedure reduces the amount of elements released from 25% up to 90%