Selecting Denture Teeth

1
Selecting Denture Teeth
2
Place reference marks on the occlusion rims to
aid in tooth selection and placement
3
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

4
Maxillary Reference Marks
5
Midline Position

• Critical reference
• 7 wax spatula
• Score a line parallel the facial midline
• Mark both rims

6
Guidelines for Setting Anterior Teeth
High Lip Line
Corner of Mouth
Angulation is as important as midline
7
Midline of Teeth Facial Midline

• Mark midline on the wax

8
Corners of the Mouth

• Mark corners at rest (7 wax spatula)
• Position of distal of the canines

9
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.)

10
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

11
Palatal Midline

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

12
Midline Canine Reference

• Line passing through distal of incisive papilla
• Perpendicular to the palatal midline
• Intersects cusp tips of the canines

Natural Dentition
13
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

14
Mandibular Reference Lines
15
Mandibular Reference Lines
16
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

17
Center of Posterior Ridge

• Maxillary lingual cusps should be centered over
  this line
• Ensures denture stability
• Reduces fulcruming forces during function

18
Center of Anterior Ridge

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

19
Selecting Anterior Teeth

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

20
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?

21
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

22
Measuring Existing Teeth
23
Tooth Size Selection

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

24
Tooth Size Selection

• Corners of Mouth - use the Auto-Rule to pick a
  mould

25
Shape Selection

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

26
Shape Selection

• Use existing teeth as a guide - do they look good
• USE COMMON SENSE OBSERVATION

27
Use Negative Space

• Look at interproximal embrasure and papilla shape
  to assist in determining tooth shape

28
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

29
Shade Selection

• Dont show all shades to patient
• Patients will pick the whitest
• Show 2 or 3 shades under lip
• Colour perception affected by background

30
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

31
Squint Test

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

32
Shade Selection

• Teeth darken with age
• Correlation with skin and hair colour is suspect
• Vita C shades are greyish

33
Patient Chooses Shade with Input from Dentist

• Patient
• owns the dentures
• will look at them every day
• Offer your opinion, dont persuade

34
Disinfect Shade Tabs
35
Denture Tooth Material

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

36
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
• Dont bond to base (stain, fall out)
• Difficult to set, adjust

37
Selecting Posterior Tooth Form
38
Anatomic Teeth (10, 20, 30, 40)

• Use for patients with
• Esthetic concerns
• Coordinated jaw movements
• Denture opposing natural teeth

39
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

40
Non-Anatomic Teeth

• No overbite
• Normal overjet (1-2mm)

41
No tooth form has been proven most efficient -
most patient cant discern a difference
42
Posterior Tooth Selection

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

43
Posterior Tooth Selection

• Buccolingual size can affect the tongue space
• smaller teeth if tongue space is limited

44
Prescribing Denture Teeth

• Use paper mould guides
• Infection control

45
Prescribing Denture Teeth

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

46
Summary

• Selecting denture teeth
• advise patient dont persuade
• an art, minimal science
• use common sense
• use old denture as a starting point
• look at dentate patient esthetics
• Seminar exercise

47
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