Calculus attachment. Review of the literature and new findings.

This study was undertaken in order to provide current information relative to the modes of calculus attachment to tooth surfaces. A total of 63 freshly extracted teeth were fixed, sectioned, and conventionally prepared for light, transmission electron, and scanning electron microscopic examination. Previously reported histologic findings of cuticular attachment, mechanical locking into undercuts, and direct attachment of calculus matrix to the tooth surface were affirmed. The claim of bacterial penetration as a mode of attachment has been rejected. Ultrastructural evidence of cuticular attachment has been presented for the first time via a series of scanning electron micrographs. The most frequently encountered method of attachment was found to be the apparent melding of calculus matrix to the surface of cementum. In many instances, these two substances were virtually indistinguishable.