The Role of the Acquired Enamel Pellicle in Calculus Formation

Abstract

This article reviews a new concept of pellicle formation based on recently published data, and some experiments concerning the role of the pellicle in relation to calculus formation. There are strong indications that the pellicle consists of a multilayer of globules with a diameter of from 20 to 300 nm. These globules have a raspberry-like surface with clusters of smaller globules which are bound together by calcium, probably by bridging. The globules have negatively charged surfaces and hydrophobic interiors and are very similar to the micelles present in milk. It was shown in the present experiments that the pellicle inhibited seeded precipitation of calcium phosphates on enamel in a saturated solution. It was further shown that several proteolytic enzymes were able to release peptides from both milk micelles and from salivary globules, and that this treatment eliminated or reduced the inhibiting effect of the pellicles with regard to precipitation of calcium phosphates on enamel. It is suggested that this may be related to calculus formation in vivo, and that the pellicle normally inhibits calculus formation, but that proteolytic enzymes from bacteria in the oral cavity degrade the pellicle and cause it to lose its inhibiting effect.