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 • Don’t 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, don’t 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. 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 Denture Tooth Material

37. Selecting Posterior Tooth Form

38. 30° 20° 10° 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 can’t 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 don’t 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