Selecting Denture Teeth

Place reference marks on the occlusion rims to aid in tooth selection and placement

Reference Marks for Selecting Anterior Teeth Technician sets the teeth without seeing patient Wax rim contours aid selection and setting: Occlusal vertical dimension Angulation of facial rims affects lip support Overjet

Maxillary Reference Marks

Midline Position Critical reference #7 wax spatula Score a line parallel the facial midline Mark both rims

Guidelines for Setting Anterior Teeth High Lip Line Corner of Mouth Angulation is as important as midline

Midline of Teeth = Facial Midline Mark midline on the wax

Corners of the Mouth Mark corners at rest (#7 wax spatula) Position of distal of the canines

Corners of the Mouth Measure circumference between marks with Trubyte Auto-Rule Size of 6 anterior teeth read off ruler (mm or by letter code A, B, etc.)

High Lip Line Highest point of upper lip when smiling Cervical necks lie at or above this line If shorter teeth are selected, esthetics compromised

Palatal Midline Through middle of incisive papilla & mid-palatal raphe Extend onto land area Check for symmetry If not symmetrical, adjust rim

Midline & Canine Reference Line passing through distal of incisive papilla Perpendicular to the palatal midline Intersects cusp tips of the canines Natural Dentition

Distal Aspect of the Incisive Papilla Provides verification & tooth size selection Use to verify the symmetry On average, facial of central incisors should be 8-10 mm anterior to this line

Mandibular Reference Lines

Mandibular Reference Lines

Middle of Retromolar Pads Occlusal plane intersects If occlusal plane is too low - tongue biting Too high - strain as tongue struggles to replace the food bolus

Center of Posterior Ridge Maxillary lingual cusps should be centered over this line Ensures denture stability Reduces fulcruming forces during function

Center of Anterior Ridge If anterior teeth are too facial to center of ridge, fulcruming tilting and dislodging occur

Selecting Anterior Teeth Combination of science and art Measurement, formulas etc. are a starting point Use vision and common sense

Tooth Size Selection Use existing teeth as a guide: Too big or small? If so, use your own judgment Does patient like them? Do you?

Tooth Size Selection Use existing teeth as a guide: If acceptable, measure width and length Compare to Trubyte mould guide chart Central incisors dimensions listed Tooth photos are life size

Measuring Existing Teeth

Tooth Size Selection High Lip Line - indication of inciso-gingival length Pre-extraction cast or photographs can be useful

Tooth Size Selection Corners of Mouth - use the Auto-Rule to pick a mould

Shape Selection Tooth shape does not correspond to facial shape Trubyte system good starting point No proven male/female characteristics

Shape Selection Use existing teeth as a guide - do they look good USE COMMON SENSE & OBSERVATION

Use Negative Space Look at interproximal embrasure and papilla shape to assist in determining tooth shape

Shade Selection Portrait shade guide Use existing teeth as a guide Shade B2 is close an average shade Top number (A, B, C, D) on tabs corresponds to Vita porcelain shade Bottom number (P) is Portrait # for ordering

Shade Selection Don’t show all shades to patient Patients will pick the whitest Show 2 or 3 shades under lip Colour perception affected by background

Check Shade Against the Patients Face Check shade of existing denture Ask if patient wants same shade or change Allow patient to view shade against lip with mirror Obtain patient approval

Squint Test Check for value (brightness) Squinting reduces the influence of hue If the teeth look too bright while squinting, suggest something less bright

Shade Selection Teeth darken with age Correlation with skin and hair colour is suspect Vita ‘C’ shades are greyish

Patient Chooses Shade with Input from Dentist owns the dentures will look at them every day Offer your opinion, don’t persuade

Disinfect Shade Tabs

Denture Tooth Material Porcelain teeth less common now Acrylic easier to set and adjust Last life of denture (5-7 years)

Denture Tooth Material Acrylic New acrylics wear better Improved translucency with layers More resilient - Less breakage Chemically bonds to base Quieter Easier to set/adjust Gum sticks Porcelain Less wear More translucent Brittle - fracture easily Don’t bond to base (stain, fall out) Difficult to set, adjust

Selecting Posterior Tooth Form

Anatomic Teeth (10°, 20°, 30°, 40°) Use for patients with: Esthetic concerns Coordinated jaw movements Denture opposing natural teeth 10° 20° 30°

Non-Anatomic Teeth (0°, Rational, Monoline, etc.) Jaw size discrepancies (Class III) Severe ridge resorption Uncoordinated jaw movements Poorer esthetics, due to lack of cuspal inclines

Non-Anatomic Teeth No overbite Normal overjet (1-2mm)

No tooth form has been proven most efficient - most patient can’t discern a difference

Posterior Tooth Selection Match size & shade to anteriors Determine distance from distal of canine to ascending ramus (29, 30 mm, etc.)

Posterior Tooth Selection Buccolingual size can affect the tongue space smaller teeth if tongue space is limited

Prescribing Denture Teeth Use paper mould guides Infection control

Prescribing Denture Teeth Dentsply Trubyte Portrait Acrylic Teeth Layers of acrylic - improved translucency IPN - improved wear resistance

Summary Selecting denture teeth advise patient don’t persuade an art, minimal science use common sense use old denture as a starting point look at dentate patient esthetics Seminar exercise

Seminar Exercise Work in pairs in seminar groups Select shade for partners Use maxillary cast and Boley gauge to select tooth mold that best approximates partner Select corresponding mold for mand. teeth Complete prescription for teeth Have faculty seminar leader check & sign