Section 872.3260 - Cavity varnish(a)Identification. Cavity varnish is a device that consists of a compound intended to coat a prepared cavity of a tooth before insertion of restorative materials. The device is intended to prevent penetration of restorative materials, such as amalgam, into the dentinal tissue.(b)Classification. Class II (special controls). The device, when it is an external cleaning solution, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 872.9 .52 FR 30097, Aug. 12, 1987, as amended at 84 FR 71812 , Dec. 30, 2019