Excavation of caries lesions induces transient decrease of total salivary immunoglobulin A concentration

Salivary immunoglobulin A (IgA) secreted by salivary glands is the predominant humoral factor of the local immune system in the oral cavity. Epidemiological studies emphasize the importance of salivary IgA in the protection from infections and caries. This study investigated how excavation of caries lesions affects total salivary IgA concentration. Fifteen patients were assigned to two sessions: the first session consisted of the excavation of a caries lesion. Thirty min before, during, directly after, and 30 min after the excavation, patients were asked for saliva samples. One wk later, a control session was performed on the same patients at the same time of the day, consisting of a dental inspection without any drilling. Marked, transient decreases were observed in concentration and secretion rate of total salivary immunoglobulin A during and immediately after caries excavation. Thirty min after caries excavation, immunoglobulin A concentrations returned to baseline. No differences were found between sessions with regard to saliva flow and cortisol concentration. It was concluded that transient decreases of total salivary immunoglobulin A concentrations are induced by excavation of caries lesions.