12-Arranging Artificial Teeth in RPDs

The artificial posterior teeth on the CD/, which oppose lower natural teeth are set in

Hyperocclusion; the teeth cause the incisal guide pin to be lifted off the incisal table of the articulator 1-2mm, then ground down until the pin touches

Why might artificial posterior teeth on a mandibular RPD opposing a CD/ may not need to be adjusted occlusally?

Becuase their position may be adjusted antero-posteriorly until the correct interdigitation of cusps is achieved

How can you adjust teeth that line up cusp-to-cusp (when viewed buccally) due to an unusual jaw relationship?

By widening and eliminating transverse ridges

What should you do to have good adaptation of the artifical tooth adjacent to the abutment tooth

Grind the artifical tooth to the guiding plate

For best appearance, the natural and artifical teeth at “X” should contact, but not be tightly adapted under a wire clasp “Y” why?

Because the wire would be distorted during processing of the resin base (the artifical teeth are pulled off the wax base when the processing flask is opened and a plastic tooth hooked under the wire clasp may bend the wire)

Sometimes, the space “S” is SO narrow that you may have to grind away 50% of a plastic premolar to allow the tooth to fit. How are the teeth set?

The maxillary anterior teeth are set a little anterior for lip support and/or to provide clearance in CO. And the max posterior teeth are set more forward

How are teeth set in a NAT/RPD case?

The artificial teeth are set in hyperocclusion (VD increased 1-2mm) and ground down until correct VD is reestablished

What is the sequence for arranging teeth in a CD/RPD?

1. Maxillary anterior teeth

2. Maxillary posterior teeth

3. Mandibular posterior teeth

4. Complete wax-up

Why do you set maxillary anterior teeth first?

To establish esthetics, overjet, overbite, and incisal guidance

Why should you leave ~1 mm clearance between maxillary and mandibular anterior teeth

To protect the maxillary anterior ridge from excessive forces

After setting anterior teeth, why do you adjust the articulator?

Because the posterior teeth must harmonize with the anterior guidance

Why must artificial posterior teeth contact opposing natural teeth in centric?

To provide an occlusal stop if the RPD is removed

What is the foundation for good eccentric balance?

Accurate centric occlusion

Why should you allow plenty of buccal overjet

To prevent crossbite interferences and help achieve balanced articulation

Don't force a tooth into a space that doesn't exist (sometimes, there isn’t room for #20).

Maintaining occlusion and alignment is more important than replacing every tooth

What is a common error that causes poor articulation and results in poor appearance?

Leaving the gingival aspect of the tooth in a buccal position rather than adapting it around the framework elements