LLU School of Dentistry Dentalgram - helpful hints

1. Adjust contact points to permit passage of the crown.

2. Items needed: a. Alcohol lamp; b. PKT waxing instrument; c. Kerrs Disclosing Wax

3. Deposit a small bead of disclosing wax (sesame seed-poppy seed size) into the center of the occlusal surface. Be sure the casting is dry.

4. Seat the casting on the tooth as far as it will go. Be sure the tooth is wet.

5. Remove and inspect the bead of wax. Do not waste time inspecting the margins. The wax will quickly provide the evidence if the wax patty has been squashed to thinness, when the casting is seated.

6. Remove the wax by heating the casting over an alcohol flame followed by a blast of air from the syringe.

7. The area found in gingival margin regions will be most likely to check. Paint a 2 mm-wide strip of wax circumferentially inside the crown. Reseat the casting, remove and inspect. Most likely any “high” area will be identified. Relieve the gold with a bur.

8. Reseat the casting again with a wax bead to see if the wax casting is seated better than before.

9. If it is still “high,” and marginal areas are okay, paint a strip of molten wax along the occlusal part of the axial walls.

10. Failure to seat the crown could also be caused by contact points from adjacent teeth. To verify contact point interference, place a postage stamp-size of carbon paper in between the adjacent teeth and seat the casting. Heavy marking could be caused by proximal interference. Avoid using “Fit Checker.” It covers too much of an area. Disclosing Wax is much more accurate and systematic in locating “high spots.” Moreover, Fit Checker is rubbery and catches in the bur when attempting to remove the metal.