TEETH SELECTION in prosthodontic dentistry

Precision attachments

1. SELECTION OF TEETH FOR COMPLETE
DENTURES

2. HISTORY
INTRODUCTION
SELECTION OF ANTERIOR TEETH
•Size
•Form
•Colour
SELECTION OF POSTERIOR TEETH
•Size
•Form
•Colour
SELECTION OF TEETH MATERIALS
CONCLUSION
REFERENCES
CONTENTS

3. Selection and arrangement of artificial teeth are apparently the esthetic imagination
and emotion of the operator combined with the physical values of beauty and
masticatory efficiency.
Denture art is a creative complex art as it deals with restoration of form, dimensions
and relations of the oro-facial region and teeth that have been lost by the patient.
INTRODUCTION

4. Teethselectionforcompletedentureisbestunderstoodiftheanteriorteethare
consideredseparatelyfromtheposteriorteeth.Theanteriorteethareprimarily
selectedtosatisfyestheticrequirements,whereasposteriorteethareselectedtosatisfy
masticatoryrequirements.
Anterior teeth selection Posterior teeth selection
SIZE FORM MATERIALCOLOR

5. ANTERIOR TEETH SELECTION
Mesio-distal width Inciso-gingival length Labiolingual thickness
SIZE

6. GUIDES FOR TEETH SELECTION
Pre-extraction Guides
Diagnostic casts
Photographs
Radiographs
Preserved extracted teeth
Teeth of close relatives
Existing old denture Int. J. Prosthodont. : 1999: 12:51-58

7. GUIDES FOR TEETH SELECTION
Post-extraction Guides
Anthropological measurements
Anatomical landmarks
Int. J. Prosthodont. : 1999: 12:51-58

8. Sears anthropometrical cephalic index(1960):
Total width of upper anteriors= bizygomaticwidth / 3.36
Width of upper central incisor = circumference of head at forehead
level / 13
Total width of lower anteriors=4/5
th
the width of upper anteriors
Berry’s biometric index:
Width of maxillary central incisor = bizygomaticwidth / 16
Width of maxillary central incisor = length of the face / 20
ANTHROPOLOGICAL MEASUREMENTS
SIZE

9. Pound’s formula:
Width of the maxillary central incisor = bizygomaticwidth / 16
Length of the maxillary central incisor = length of face / 16
SIZE

10. Location of canine eminence/buccal
frenum
Location of the corners of the mouth
Location of the alaof the nose
Size of the maxillary arch
Maxillo-Mandibular Relation
Contour of the residual ridge
Vertical distance between the ridges
Position of the lips
ANATOMICAL LANDMARKS
SIZE

11. The S.P.A. Factor
The S.P.A. factor, the evaluation of sex, personality and age as regards of the prospective denture
wearer, was the first to become fully evaluated.
The incorporations of these factors in denture esthetics is extremely important as “A woman is a
woman from her finger tips to her smile” and “A man is a man from his fist to his smile”. But
how often are the smiles of either sex completely neutralized by the usual dentures.
THE SPA FACTOR
FrushJP, Fisher RD : Dentogenics: its practical
application :
J. Pros. Dent.: 1959:9:914-921
FORM

12. The concept of “Dentogenics”must be given favourableconsideration.
Fischer states “we utilize the approach of the artist when we analyze the patient first as
to sex, personality and then age.
ROLE OF DENTOGENICS IN SELECTION OF ARTIFICIAL
TEETH
SEX PERSONALITY AGE
FEMININE
MASCULINE
DELICATE
MEDIUM PLEASING
VIGOROUS
YOUNG AGE
MIDDLE AGE
OLD AGE
FORM

13. The original concept of this important consideration belongs to Wilhelm Zech, a sculptor of
Switzerland. He reasoned that it is possible for the sculptor to express vigor and delicacy, vigor
representing masculinity and delicacy representing feminity, in his work of art.
Feminityis expressed in the female form by roundness, smoothness and softness.
Masculinity is expressed as aggressiveness, boldness, hardness, strength, action and forcefulness.
HOW DENTOGENIC RESTORATIONS
INTERPRET THE SEX FACTOR
FORM

14. EXPRESSION OF FEMININE OR MUSCULINITY
CHARACTERS
Curved features / Square features
Roundness of the arch form / squarish
Incisaledges of the maxillary anterior
Teeth follow the curve of lower lip
Lateral incisor narrower and shorter than the centrals
Lateral incisor rotated to show its mesial slightly
overlapping the centrals gives softness to smile.
FORM

15. Prominent cuspideminence more
suitable to the masculine sex.
Distal surface of the cuspidsfor
females are rotated in a posterior
direction.
Womenexposemoremaxillaryteeththana
manwhenspeaking,smiling,orlaughing,
somainconcerninarrangingthefirst
premolarisestheticsforfemales.
FORM

16. The type of central and lateral incisor and cuspid
which would be used for the youthful and fit
patients
Centralincisorsconsiderablymorecoarse
andareforamplebodied,obesewomen
FORM

17. Consider light shades for young people and darker shades for older ones.
Smile line loses its sharpness in older age
Interincisaldistance increases, increased visibility of mandibular teeth, also
because of loss of muscular tone.
EXPRESSION OF AGE CHARACTERISTICS
FORM

18. DENTOGENIC CONCEPT
Anterior teeth modification for dentogenic
restoration can be remembered andEmployed by a
simple one, two and three guide.
One -central incisor, expresses Age
Two-lateral incisor, expresses Sex
Three -cuspidexpress Vigor
FORM

19. Color is the sensation resulting from stimulation of the retina of the eye by light waves of certain
wavelengths.
Shade is the degree of darkness of a color with reference to its mixture with black.
Billmeyerand Saltzman (1966) defined color as a result of the physical modification of light by
colorants as observed by the human eye and interpreted by the brain.
COLOR OR SHADE OF ANTERIOR TEETH

20. Refers to the characteristics of a color that give its identity and differ it from other
colours. Red is a hue, so are yellow, blue and other coloursthat are known by name.
Refers to how much of the actual pigment is in the color being described. For
example, a strong red has a heavy hue pigment concentration. A weak red may
have the same quality of hue pigment, but it also has other coloursor neutrals
mixed with it, which dilute the effect of the red pigment.
HUE
CHROMA / SATURATION
COLOUR

21. Describes the lightness or darkness of a colour. It is the most important quotient with which
we are concerned in dentistry.
It is the property of an object that permit the passage of light through it but can not give any
distinguishable image.
Translucency is the quality seen when the mouth is illuminated in different lights.
VALUE / BRILLIANCE
TRANSLUCENCY
COLOUR

22. Prescribelightteethforyoungpatientsanddarkerteeth
forolderones.
TheMunsellcolourordersystemwasdesignedtofulfill
therequirementsoftheidealcolourspace.Itis
recommendedasthesystemofchoicefordentistswho
wishtogainaworkingknowledgeofcolour.

23. POSTERIOR TEETH SELECTION
SIZE
FORM
Cusped teeth
Cuspless teeth
Mesio-distal length
Bucco-lingual width
Occluso-gingival height
Anatomic
Semi-anatomic
COLOR
MATERIAL

24. This extends from the distal of the lower canine to the apex of the retromolarpad
A ruler or a space gauge is used to measure the distance available and is related to the size of
available molds.
The extent of the occlusaltable in the mandibular arch should not be carried further posteriorily
than the region at which the residual ridge turns upwards to make its ascent to the retromolarpad.
MESIO-DISTAL DIMENSIONS OF POSTERIOR
TEETH
SIZE

25. The posterior teeth must support the cheeks and tongue and function in harmony with the
musculature while speaking, swallowing and masticating.
The Buccolingualdimension of the artificial teeth is kept less than that of the natural teeth so as
to reduce the size of the food table. This reduction should not be at the expense of loss of
support for the cheeks.
The Buccolingualdimensions should not be great to embarassthe tongue or encroach on the
normal buccalcorridor space.
Narrow buccolingualposteriors allows correct form of polished surface of the denture and
permit surrounding tissues to function around the denture base hence aid in denture stability.
BUCCOLINGUAL DIMENSIONS OF POSTERIOR
TEETH
SIZE

26. Available inter-arch space
Size of the anterior teeth
Longer posterior teeth are generally more esthetic in appearance than shorter teeth.
The height of the maxillary first premolar should be comparable with that of the maxillary canines to have the
proper esthetic effect. Without this relationship, the denture base material will appear unnatural distal to the
canines.
Ridge lapping the posterior teeth can be done without sacrificing leverage or esthetics.
OCCLUSO-GINGIVAL DIMENSIONS OF
POSTERIOR TEETH
SIZE

27. STANDARDORANATOMICTEETH
DrAlfredGysi(1914)iscreditedfordesigningthefirstanatomicteethinporcelainwithanangulation’sof33
degrees.
TRUBYTE
Thesehave
Cuspsandfossaeasnaturalteeth
Availableasanatomicandsemi-anatomicteeth
Mostfrequentlyusedteeth
Providethebestesthetics
Intended for tight intercuspationfor Angle’s class I occlusion.
FORMS OF POSTERIOR TEETH

28. MODIFIEDANATOMICTEETH(1932)
PilkingtonandTurner
Slightlyshallowcuspswithcuspalangulationof30°
ThesewerenotastightlyinterlockedasTrubyteteeth.
FORM

29. 1.MODIFIEDCROSSBITEPOSTERIOR-(Gysi-1927)
Themaxillarybuccalcuspwasalmosteliminated,resultinginoneprominentlingualcusp
occludingintotheanatomiclowertooth.
Mortarandpestleaction
SEMI ANATOMIC TEETH (0 -30°)
FORM

30. Maxillary occlusal surfaces consisted of deep channel that ran mesio-distally the entire length of the
four posterior teeth.
Effectively it was a single ridge that ran uninterrupted the entire length of the occlusal table.
2. CHANNEL TOOTH –
(VICTOR SEARS -1922)
FORM

31. Posteriorocclusalsurface
waslockedantero-posteriorly
bygrindingstepsonthesurface
oftheteeth.
Occlusionwiththeseteeth
wasmeantforshearingfood.
3. SCISSOR BITE TEETH –
(AVERY BROTHERS -1930)
FORM

32. Theseteethweredesigned
tolockantero-posteriorly
andfreelateralmovements.
4. “CURVED CUSP” POSTERIOR
TOOTH –(MCGRANE-1936)
FORM

33. Stainless steel inserts in posteriors ; gold solder later replaced with.
Advantage claimed was that these teeth were self adjusting to wear.
5. METAL INSERT POSTERIORS –
(DR.JOHNVINCENT -1942)
FORM

34. 7.CROSSBLADES–(Sosin-1961)
•ReplacedthemaxillaryandmandibularsecondpremolarandbothmolarswithcleatshapedVitallium
formscalled“crossblades”ofslightlysmallersize.
•Anincreaseinmasticatoryefficiencyisclaimed.
J. Pros.Dent: 1977:38:3-13
FORM

35. Indications
Highly resorbed or flat ridges
Balanced occlusion is not planned
Abnormal jaw relationships
Difficult to record centric relation
Non masticatory mandibular movements like bruxism
Poor neuro-muscular control where jaw relation records are not repeatable
When the leverage associated with cusped teeth has to be avoided.
NON ANATOMIC TEETH
FORM

36. Advantages
Freedom of movement
Elimination of lateral inclined
forces
Lack of interferences during
settling
Disadvantages
Not esthetically pleasing
Lower shearing efficiency

37. ANATOMICTEETH SEMIANATOMIC NON–ANATOMIC
TEETH
TRUBYTE(True anatomic)CHANNEL TEETH INVERTEDCUSP TEETH
MODIFIEDANATOMIC SCISSORBITE TEETH CHOPPINGBLOCK
CURVED CUSP POSTERIOR
TEETH
NON LOCK TEETH
METAL INSERT
POSTERIOR TEETH
VITALLIUM OCCLUSAL
MODIFIED TEETH FOR
LINGUALISED OCCLUSION
SHEAR CUSP TEETH
CROSS BLADES COE MASTICATORS
FORM

38. Acrylic teeth
Porcelain teeth
Porcelain acrylic combination scheme
Acrylic teeth with amalgam inserts
Acrylic teeth with cast gold occlusal surfaces
SELECTION OF TOOTH MATERIAL
WehnerPJ, Hickey JC, Boucher CO : J. Pros. Dent. 1967:18:222-232

39. Cross linked to improve strength and hardness
Indications:
With opposing natural dentition
With opposing gold crown or inlays restorations
Reduced inter-arch space
In removable partial dentures teeth in contact with direct retainers
ACRYLIC TEETH
MATERIAL

40. Indications
Adequate inter ridge space
Well formed ridges
Esthetics
Porcelain acrylic combination scheme
Contraindications
Poor mandibular ridge
Opposing natural dentition
Opposing gold restorations
PORCELAIN TEETH
MATERIAL

41. A combination of resin posteriors and porcelain posteriors.
Reduces clicking sound and acrylic teeth serves as cushion and absorbs impact stresses.
A dangerous combination is porcelain anteriorscombined with resin posteriors , where
faster wear of resin posteriors causes continoustrauma to anterior denture foundation.
PORCELAIN-ACRYLIC
COMBINATION
MATERIAL

42. Amalgam stops
Amalgam is condensed in to prepared cavities in the resin teeth.
Functionally generated occlusion
Used with opposing porcelain teeth to reduce resin wear
ACRYLIC TEETH WITH AMALGAM INSERTS
Articulator generated
amalgam stops
Intra-oral generated
Amalgam stops
MATERIAL

43. The field of dental esthetics is of critical importance to the well being of patients and
one of dentistry’s greatest challenges is to completely eliminate the delivery of static,
poorly planned, clumsily executed dentures.
Thus, selection of teeth do play a vital role in the overall procedure of the fabrication
of a complete denture and its proper selection poses a great challenge to the dentist.
CONCLUSION

44. THANK YOU