A STEP-BY-STEP CUSPID HOLLOW GROUND PREPARATION

Step 1. Anesthetic is administered and an extra heavy dam is placed.

Step 2. Removal of previous restoration and caries is accomplished.

Step 3. A film of calcium hydroxide is placed over the pulpal and axial walls with a small cotton pellet and then retention potholes are placed with a1/2 round bur, if needed.

Step 4. Composite 'block-out' material is placed in cavity preparation, if necessary. The use of an old bur to rough out the cavity preparation in composite is recommended because the composite will dull the bur quickly.

Step 5. Use a #56 straight fissure bur to prepare a dovetail on the lingual of the cuspid of proper depth. Draw must exist in all directions and the extension must be adequate to give proper resistance form for the proximal hollow ground. Smooth the lingual floor with the end of the bur and extend outline form pass the contact area of the adjacent tooth, both on the labial and lingual.

Step 6. With a #7404 bur, holding the bur in the direction of draw of the lingual dovetail, move the bur labially, lingually and gingivally for proper and adequate extension. This will join the extension of the lingual dovetail outline.

Step 7. If the proximal area is larger than the lingual dovetail area, then a pin needs to be place at the base of the hollow ground for guidance and prevention of the casting splaying at the gingival. Use a #6 round bur to make a countersink at the gingival, drawing the bur out in the line of draw in order that the countersink will draw with the rest of the preparation.

Step 8. Using a #169L bur place the end of the bur in the countersink align with the line of draw of the preparation. Place to a depth of 1.5 to 2 mm.

Step 9. Smooth lingual floor with a #44S off-angle chisel.