Directions For Occlusal Reduction & Crown Preparation
Select the appropriate occlusal reduction
bur for the restorative material.
*Ideal porcelain fused to metal is 1.5mm to 2.00mm of porcelain and the coping thickness.
||Short Clinical mandibular premolar PFM Crown*
|2.0 mm Yellow
||All Ceramic, Captek, Cerec & PFM Crowns*
|2.2 mm Blue
||Long Clinical PFM Crown*
|2.4 mm Red
||Used to level occlusal plane on a superupted tooth
Start the depth grooves in the facial groove and extend into all fissures. Keep the ORB perpendicular to the external surface of the tooth for greatest accuracy.
Allow the self-limiting feature to touch the occlusal surface and then push the bur laterally.
Place extra depth grooves if possible from cusp tip to cusp tip, overlapping the functional cusp.
III. Use your preferred axial reduction bur to remove any remaining occlusal tooth structure to achieve the ideal inclined plane reduction Many dentists use the ORB to remove the remaining tooth by lightly "painting away" the tooth structure between the depth cuts keeping the bur perpendicular to the external tooth surface.
IV. Finish the axial reduction and pack a small retraction cord If no build-up is necessary, pack a secondary cord and proceed to impression and temporization.
Benefits of Ideal
Minimal chairside adjustment
Dental labs make crowns high to hide minimal occlusal clearance.
Have you ever ground to opaque or metal? Dental labs know that if the porcelain is unesthetic, doctors will not accept crowns.
The lab has several options, but the most common choices are a high crown, an adjusted opposing tooth, or a cut off coping.
Minimal metal cost
Precious metal is expensive and adds significantly to the total lab fee.
Excessive reduction leads to increased metal cost.
Porcelain can only be esthetic when proper clearance is given for layering techniques.
Checking and rechecking clearance is tedious and impossible on lingual cusps.
Grinding a crown from the lab not only takes time but also diminishes a patient's confidence.
No more excuses
Esthetic porcelain is possible and high crowns should be rare.
I have introduced a new bur for precise palatal (lingual) reduction on maxillary anterior teeth.
The bur has a white band and it is 1.0 mm in depth.