Adsorption of salivary and serum proteins, and bacterial adherence on titanium and zirconia ceramic surfaces

Abstract

The aim of this study was to determine the pattern of salivary and serum proteins present in pellicles formed on titanium (Ti) and zirconia ceramic (ZrO(2)) surfaces, and the ability of bacterial cells to adhere to the experimental pellicles. In addition, the protein profiles and bacterial binding properties of pellicles on Ti and ZrO(2) were compared to those formed on hydroxyapatite (HA) surface. The pellicles were formed in vitro by incubating the materials with whole saliva, serum or saliva+serum. Protein composition in each of the pellicles was investigated by SDS-PAGE and immunodetection. The adherence of radiolabeled Streptococcus mutans and Actinomyces naeslundii to uncoated surfaces and experimental pellicles was determined by means of scintillation counting. Statistical analyses were done using ANOVA and Tukey's test at significance level at P<0.05. In general, the electrophoretic analysis of the pellicles formed on HA, Ti and ZrO(2) revealed few qualitative differences of the composition of proteins of the pellicles formed on HA, Ti and ZrO(2) surfaces. Pellicle components identified included amylase, IgA, IgG, albumin, fibronectin and fibrinogen. The number of S. mutans cells adhered to uncoated Ti and ZrO(2) was significantly higher than those adhered to HA (P<0.05). In contrast, lower number of A. naeslundii cells adhered to uncoated Ti and ZrO(2) than to HA (P<0.05). However, the presence of saliva and saliva+serum pellicles greatly reduced the number of S. mutans cells bound to each of the surfaces. The data showed that Ti and ZrO(2) display similar pellicle protein composition and bacterial binding properties; however, significant differences were observed when both materials were compared to HA.