ADSORPTION OF HUMAN SALIVARY PROTEINS TO TITANIUM POWDER .1. ADSORPTION OF HUMAN SALIVARY ALBUMIN

Titanium (Ti) is among the most widely used implant materials in denti stry today. The success of Ti implants is associated with their intera ctions with the surrounding tissues and biological fluids. In the pres ent study, the adsorption of salivary proteins to Ti and the effect of calcium (Ca) on this process were investigated. Untreated and Ca-trea ted Ti powders were suspended in human clarified whole saliva. After i ncubation, the supernatant fluid was collected for protein analysis. T he powders were then washed and resuspended in EDTA to desorb proteins from Ti surfaces. Sodium dodecylsulphate polyacrylamide gel electroph oresis and Bradford protein assay were conducted to determine the conc entration and type of proteins that adsorbed onto Ti surfaces. The pre sence of Ca ions enhanced the adsorption of salivary proteins to Ti. A 66 kDa protein, identified by immunoblotting as albumin, was found as the main adsorbed salivary protein. Adsorption of albumin to Ti pretr eated with Ca was significantly greater than to native Ti. The Ca-depe ndent adsorption process was reversed by EDTA. The data suggest that s alivary albumin is one of the main constituents of a salivary biofilm formed on Ti dental implants and its adsorption to Ti surfaces is Ca-d ependent. The presence of albumin on Ti dental implants may affect pla que accumulation on the implants and the biocompatibility of Ti implan ts.