# 23 Full Crown Wax Up

Standardized Approach Terminology & Nomenclature Waxing Techniques Dental Anatomy

Standardized Approach Follow a logical series of steps Use anatomical references that are present: on the tooth peg adjacent teeth contra-lateral tooth opposing teeth A purely artistic approach is very difficult

Anatomical References Embrasures Line Angles Heights of Contour Point Angles Proximal Contact Areas

#23 Tooth Peg

The tooth peg is actually a prepared #23 dentoform tooth.

The end of the preparation is the finish line. The adaptation & contour of wax at the finish line creates the margin.

Notice the smooth transition from the un-prepared portion of the tooth peg to the image of the crown form.Your wax ups should demonstrate the same smooth transition from unprepared tooth peg to wax.

Focus on One component at a Time Evaluate each component from multiple views: Facial Lingual Occlusal Lateral

Beginning at the most incisal point, add a thin coat of wax to the prepared surface of the peg.Melt each addition into previously applied wax.

Add a band of wax around the margin; melt wax into and past the finish line. Add slightly more contour than you see on the unprepared tooth peg. Establish Fit and Contour at the Margin

Use a Hollenback carver to carve the wax flush with the finish line and with the proper contour. The margin will become very distinct when properly carved. This is a mechanical process. Creating a Margin

Begin the margin trim with the tip of the carver in contact with the tooth peg below the finish line. The blade of the carver is 90° to the wax.

As you carve away wax rotate the blade toward the finish line.

As you continue to carve away wax rotate the blade toward the finish line until the unprepared tooth structure stops you. This is a learned tactile skill.The only thing you observe visually is the appearance of a clean, distinct junction.

Keep the wax shavings under control!

Locate Proximal Contacts

Occlusogingival Proximal Contact Location Typically the occlusogingival location of proximal contacts is most occlusal at the midline and moves more gingival as you move away from the midline.

With a pencil, mark the “typical” location for the mesial proximal contact.The red mark indicates where the contact would need to be for a rotated, overlapping tooth. Faciolingual Location of Proximal Contacts

Mark the location for the distal contact of #23.You can look at the contralateral contact area for reference.

The arch is “turning the corner” at this point. It is very easy to place your mark too far to the facial.

Beginning with a small increment of wax build a cone toward one of the marks. Verify that you are heading in the correct direction.

Add small increments to the cone, allow the wax to cool slightly (allow the shine to disappear), then replace the peg in the dentoform.Continue until the cone makes firm contact with the mark.

Repeat the process for the distal proximal contact. Proximal contact location are very specific, try to be precise with your cone locations.

From “Ten Rules for Developing Contours in Restorations”Dr. James G. Burch, D.D.S. Rule 5: “The proximal surface between the marginal ridges and the CEJ is always flat to slightly concave both buccolingually and occlusocervically.” Paraphrase: Proximal surfaces are relatively flat from the contact area to the cervical line.

We can now add wax from the margin we created to the proximal contact that we created, keeping the surface relatively flat.

Mesial Distal

Inspect from the facial: Are the gingival embrasures open?Compare these to the contralateral embrasures.The profile of the proximal surfaces should be relatively flat.

Make the same comparisons from the lingual. What do we do next?

What visual references do we have for the proper positioning of the incisal edge? Occlusal embrasure form Facial & Lingual embrasure form Facio-incisal and linguoincisal line angles Opposing tooth contacts Contralateral outline form

Occlusal Embrasure Form: Form the point angles (corners) of the incisal edge so that the occlusal embrasures are mirror images of the contralateral embrasures.

Add wax to the mesial and distal occlusal embrasure areas.Use the contralateral tooth as a guide.

Add wax between the mesial an distal point angles; this gives you an initial indication of the outline profile when viewed from the facial.To this point you are referencing occlusal embrasure form.

Opposing tooth as reference: You can manually position the lower member of your dentoform so that the teeth adjacent to #23 are in contact.

At this position the incisal edge of #23 should either be slightly in contact or be slightly out of contact with the opposing tooth.

Facial embrasure Lingual embrasure Occlusal View

Facioincisal Line Angles Linguoincisal Line Angles

The facioincisal & linguoincisal line angles form the faciolingual boundaries of the incisal edge.These are very useful references to use in positioning the incisal edge.

Add wax to develop the faciolingual width & location of the incisal edge.Your references are the facial embrasures, facioincisal and linguoincisal line angles.This step is viewed from the incisal.

Facial & Lingual Line Angles Transitional junctions between one surface and another, i.e. facial to mesioproximal Properly positioned line angles yield proper contours & pleasing esthetics.

Mesiofacial Line Angle Distofacial Line Angle

Add wax to create the mesiofacial and distofacial line angles.Reference: the contralateral tooth. Check and adjust these using facial, occlusal and lateral views.

Lateral View

Occlusal View - Evaluate facial embrasures

The lingual line angles of anterior teeth are the marginal ridges.The lingual height of contour is the cingulum.Add wax to create these structures using the same methods that were used on the facial.

Lingual View

Occlusal View Evaluate lingual embrasures

Remove the tooth from the dentoform. There will be “gaps” between the line angles just formed and the proximal surfaces that were formed previously.Blend these areas on all four line angles.

From either proximal view the waxing should appear to be complete.Do not try to eliminate the facet at the proximal contact.

Complete the facial surface, including the height of contour.The boundaries are in place.The wax will be thin over the facioincisal aspect of the peg.Evaluate contours from facial, occlusal and lateral views.

Complete the lingual fossa.Remember that a fossa is slightly concave.

Cleiod“Claw” Discoid “Discus or Round” The discoid end of the Cleiod-Discoid carver is handy for refining the lingual fossa.

Final Contouring and Smoothing Heat smooth as well as you can Plane the surface with a carver Make necessary adjustments with additions of wax and/or heat smoothing Plane the surface again Repeat the sequence as needed Buff lightly with nylon or cotton

Use light pressure and hold the blade at a 90° angle to the wax.Let the blade gently ride the contours that you have developed.Apply more pressure only when you want to reduce a contour.

One of the final steps is re-sealing the margins. First, re-melt the wax into the junction of the margin and finish line.Then add a small excess of wax over the junction & heat smooth to incorporate.Re-trim the margin and blend the contours.

Facial View

Lingual View

Lateral View

Occlusal View

Remove the waxing from the dentoform and verify that the transition from the unprepared tooth to the wax is smooth.At this point you can hold the unprepared #23 tooth adjacent to your wax-up and compare contours.

Nomenclature : Dilaceration-an abnormal angulation in the Root (or crown) of a formed tooth.

Normal Recession of the periodontium resulting in a longer clinical crown. This is called “passive” eruption since the teeth are not really moving or erupting, but the receding gums create the impression of active tooth movement. Passive Eruption

Passive eruption

Alerted Passive Eruption

Root of the Maxillary central incisor has a small distal inclination

Proximal view: 28 degrees(apex tilted lingually) Labial view: 2 degrees(Apex tilted mesially) AXIAL INCLINATION

I know that something is not right but I can’t figure out what it is!

Midline/Facial View – Symmetry at the midline is the most important esthetic consideration.

Locate Size and Location of Proximal Contacts

Great view for seeing contours of an anterior tooth.

While focusing on the midline, make sure all four point angles on the incisal edge are of the correct length and shape.