Transcript Selecting and Setting Denture Teeth

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
Center of ridge
Posterior
1/2 way up
retr omolar
Mandibular
Cast
Land Area
Ar ea
Occlusion rim
Center of ridge
Anterior
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
QuickTi me™ and a
T IFF (Uncompressed) decompressor
are needed to see thi s pi cture.
QuickTi me™ and a
T IFF (Uncompressed) decompressor
are needed to see thi s pi cture.
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
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
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
• Patient
– 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
Porcelain
Less wear
More translucent
Brittle - fracture easily
Don’t bond to base
(stain, fall out)
Difficult to set, adjust
Acrylic
New acrylics wear better
Improved translucency with
layers
More resilient - Less breakage
Chemically bonds to base
Quieter
Easier to set/adjust
Gum sticks
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