A carbon coated filament cord for marking the sidewall of dental prostheses. The carbon coated filament cord is made up of a strand of filaments having a core and a marking coating placed around a circumference of the core along the length of the strand of filaments. The diameter of both the core and the marking coating is sized to fit within an interproximal spacing between teeth and dental prostheses such as crowns, bridges or onlays. When pressure is applied to the strand from the tooth and adjacent prosthesis, an easily identifiable mark is left on the sidewall of the prosthesis at that position, allowing a dental professional to easily locate the area that requires further work.

A lathe adaptor assembly for mounting at least one polishing wheel to a spindle of a dental lathe. The lathe adaptor assembly comprises a first retention bolt with a hollow interior, a hollow bolt head, a reinforced internal structure, and an exteriorly-threaded end for engaging the spindle to secure the lathe adaptor assembly, a second retention bolt also featuring a hollow interior and an exteriorly-threaded end, and a center carrier equipped with a central throughbore designed to mount a first polishing wheel and a second polishing wheel, each secured by friction to prevent rotation on the center carrier.