Original Articles
Influence of Phosphoric Acid Solutions on the Impact Sliding Wear Characteristics of Bovine Enamel
2013 Volume 56 Issue 5 Pages 423-430
Details
2013 Volume 56 Issue 5 Pages 423-430
Purpose: Dental erosion is defined as the pathologic, chronic, localized loss of hard tooth tissue that is chemically etched away from the tooth surface by acid and/or chelation without bacterial involvement. Although numerous chemical factors have been identified to influence the erosive potential of acids, limited information exists about the effects of the physical or physico-chemical aspects of the acid on dental erosion. The purpose of this study was to investigate the influence of phosphoric acid solutions on impact sliding wear characteristics of bovine enamel. Methods: Bovine enamel samples were embedded in acrylic resin, and specimens were successively wet ground on #400〜#2,000-grid SiC paper. Phosphoric acid (PA) solutions at pH levels of 3, 5, and 7 were obtained with the mixture of phosphoric acid and disodium hydrogen-phosphate into deionized water. Specimens were immersed into PA solutions and then subjected to an impacting-sliding wear test at an impact load of 25 N in a wear simulator for up to 5,000 cycles. The volume loss and line profile of the wear facets were obtained for each specimen using laser scanning microscopy (LSM). Knoop hardness measurements and scanning electron microscopy observations were also conducted. Two-way ANOVA followed by Tukey's HSD test were performed (α=0.05). Results: The wear loss and surface roughness of enamel after the impacting-sliding wear test differed, depending on their pH values. The volumetric loss ranged from 18.1 to 207.6×10-4mm3 for pH 3 group, from 12.1 to 78.6×10-4mm3 for pH 5 group, and from 7.8 to 37.0×10-4mm3 for pH 7 group. Lower Knoop hardness was detected for the specimens immersed in pH 3 solution than the other solutions. From the LSM observations, different worn surfaces were observed due to the impact and environmental pH. Conclusion: From the results of this study, it is indicated that the wear pattern of the enamel might be affected by the different pH conditions.
