INCLINED-PLANE CUSP REDUCTION METHOD : 10% SHOED-CUSP REDUCTION
Depth cut: Penetrate the cusp at a number of points to at least half the depth of a 330-bur inserted vertically into the occlusal surface to the extent of its dentate portion, which is 1. 8 mm. This will create a shoe of 0.9 mm thickness, complying with Axiom #4, Lifespan. The photo below shows a deeper penetration-almost the full dentate portion of the bur in this case.
- Follow the cavosurface The reduced cusp will not be perpendicular to the long axis of the tooth, but will follow the incline of the cusp arm
- Bevel the cavosurface, with a mild bevel, of 6 to 12 degrees, using the 7406 burs, at low rpm, in the handpiece held perpendicular to the lingual or buccal cavosurface.The bevel begins at the DEJ. If a greater bevel is desired, incline the handpiece to increase the bevel. Use a sharp bur to perform this bevel smoothly and with light pressure and sweep it back and forth over the cusp to produce a concise linear margin that will finish easily. The large diameter of the 7406 bur creates a smooth linear margin ’painted’ on the tooth.
- Observe the result with a mirror, and commit the location of the margin to memory. This speeds final finishing.
- Restore using a wet-pack placement method.