α-amylase and salivary albumin adsorption onto titanium, enamel and dentin: An in vivo study

In vivo adsorption of salivary albumin and α-amylase onto titanium, enamel and dentin was analysed following their exposure to the oral cavity for 2 h. Oral appliances in six adults served as a platform for carrying 4-mm discs of the three materials. Adherent proteins were eluted from the discs and the amounts of salivary albumin and α-amylase were measured by an enzyme-linked immunosorbent assay. While no significant difference between the adsorption of albumin and α-amylase onto enamel as compared with dentin was observed, adsorption onto titanium was significantly lower. A sample of whole saliva was also collected from each participant. The mean total amounts of albumin and α-amylase in the participants' whole saliva were 0.03 and 0.54 mg ml^-1, respectively. Titanium adsorbed significantly less (4.43%) of the total albumin than did enamel (14.30%) or dentin (18.80%). No significant difference was found in the relative amounts of α-amylase adsorbed by the three materials. This significantly selective adsorption of proteins may enable the attachment of specific bacteria and thus alter the composition of the dental plaque and its potential pathogenicity.