SELECTION OF DENTURE BASE AND TEETH
FOR REMOVABLE PARTIAL DENTURE

INDIAN DENTAL ACADEMY
Leader in continuing dental educa...
• CONTENTS
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Introduction
Definition
Functions of denture base
Ideal requirements of denture base mater...
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Attaching Resin denture base to major connector
Teeth selection
Different artificial teeth
Anterior tee...
•

INTRODUCTION

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 DENTURE

BASE
 The part of a denture that rests on the foundation
tissues and to which teeth are attached.

www.indiand...
•FUNCTIONS OF TOOTH SUPPORTED DENTURE BASE



Provide desirable esthetics.



Support the artifial tooth .



Prevent v...
• FUCTIONS OF DISTAL EXTENSION DENTURE BASE


Contributes to the support of the denture & improves stability of the
prost...
•IDEAL REQUIREMENTS OF


Bio- compatible.



Accurately adapt to the underlying tissues



Adequate Physical & Mechanic...


Ease of fabrication & repair.



Potential for future relining , rebasing.



Esthetically acceptable ,color stabilit...
• DENTURE BASE MATERIALS


Acrylic resin



Metallic

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•HEAT ACTIVATED DENTURE BASE RESIN


COMPOSITION:



POWDER
1) Poly(methyl methacrylate)
2) Initiator- Benzoyl peroxide-...
 LIQUID


Non polymerized methyl
methacrylate



Inhibitor – Hydroquinone
0.003%-0.1%.



Cross linking agent – Glycol...


HIGH IMPACT STRENGTH
MATERIALS



Reinforced with butadiene styrene
rubber



The rubber particles are grafted to
met...


RAPID HEAT POLYMERIZED RESIN



Altered initiator system



LIGHT ACTIVATED



Urethane dimethacrylate matrix with a...
FIBER –REINFORCED POLYMER


Glass, carbon/graphite, aramid and ultrahigh molecular wt
polyethylene have been used as fibe...
•MECHANICAL PROPERTIES



PMMA&PVA posses adequate tensile & compressive strength .



Transverse strength is the combin...


Impact strength –. Rubber reinforced acrylic more impact strength.



Rubber reinforced acrylic resin possesses adequa...
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• ADVANTAGES


Easy adjust & polish.



Reling & rebasing is possible .



The weight & bulk is more than cast alloys.
...
• DIS ADVANTAGES


Adaptation not as accurate as cast metal alloy.



Abrasion resistance..



Acrylic resin bases tend...
•METALLIC DENTURE BASE MATERALS REMOVABLE
PARTIAL DENTURE


High Noble casting alloys- Au- Ag- Cu -Pd



Predominantly b...
•


As early as 1949 it was estimated that nearly 80% of all partial
denture appliances were cast from Co-Cr alloys.



...








COBALT-CHROMIUM-NICKEL
- Co-50%
- Cr-25%
- Ni-19%
Other constituents
- Mo-3.7%
- C -0.2%
NICKEL CHROMIUM- MOLY...


Chromium :
Tarnish and corrosion resistance and stain less properties.



Cobalt and nickel :
In general cobalt and ni...




OTHER ALLOYING COMPONENTS :
Carbon : increases the hardness of Co based alloys.



Molybdenum : (3% to 6% )
Contrib...


Berylium :
About 1% lowers the fusion temperature range of the alloy by about
100 degrees C.



Silicone and Manganese...
•TITANIUM ALLOYS








High purity titanium (99 wt %) with O,C ,N,H atoms dissolved
interstitially.
It undergoes an ...


Titanium alloy- Ti- 6V – 4Al



Vanadium is the beta phase stabilizer with the BCC
structure.



Al alpha phase stabi...
• TYPE IV GOLD ALLOY


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







Composition :
Au - 69%
Ag – 12.5%
Cu -10%
Pd – 3.5%
Pt – 3%
Zn,Sn,Fe,In, Ga for...
MECHANICAL PROPERTIES
Metal Type

Yeild
Strength
(Mpa/Ksi)

Tensile
Strength
(Mpa/Ksi)

Elongation
(%)

Hardness
(HV)

Ela...
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ADVANTAGES OF METALLIC DENTURE
BASE


Accurate adaptation & permanence of the form



Abrasion Resistance.



Comparati...


Thermal conductivity .



Better patient acceptance.



Weight & Bulk



Metal alloys can be casted much thinner..

...
DIS ADVANTAGES


Relining & rebasing difficult.



Difficult to adjust.



It cannot be used whenever restoring the nor...


INDICATIONS:



1) Risk of fracture of resin denture base.



2)RAR atrophy



2) More room for the tongue functioni...
• THE METAL- ACRYLIC RESIN BASE


Consists of cast metal base
that fits the RAR & acrylic
resin attached to it to retain
...
•FABRICATION OF DENTURE BASE IN DISTAL
EXTENTION RPD


Distal extension RPD depends…



Extensions of the denture base

...
•SELECTIVE PRESSURE IMPRESSION METHOD
By this method the soft tisuses over the primary
supporting areas are recorded to pr...
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•METHODS OF ATTACHING THE DENTURE BASE


Minor connector joins the denture base to the major
connector.



Relief of at ...
•TYPES OF MINOR CONNECTORS


1) Open construction

2) Mesh construction
 3) Bead, nail head & wire
constructions


www....
CHEMICAL BONDING


Direct bonding of acrylic resin to metal framework.



Sections of metal frame work meant for support...



Tribochemical coating
Method for fusing microscopic layer of ceramic to metal.



Sandblasting the metal framework w...
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•SELECTION OF THE PROSTHETIC TEETH


Teeth replacement is important to reestablish the lost
facial contours, phonetics, m...
• IDEAL PROSTHETIC TOOTH SHOULD SATISFY
FOLLOWING REQUIREMNT


Pleasing appearance to satisfy the esthetic requirement.

...


Resistance to blanching, distortion ,crazing.



It should have enough strength to bear occlusal load.



Adequate re...
• TYPE OF ARTIFICIAL TEETH


Acrylic resin teeth



Porcelain teeth



Metal tooth



Acrylic resin teeth with occlusa...
•ACRYLIC RESIN TEETH


Strength adequate to withstand the occlusal load.



Chemical bonding with acrylic denture base.
...


Easy to polish.



Dose not cause the wear of the opposing natural teeth or gold
restorations.



Low heat distortion...
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• CHARECTERISTICS OF PORCELAIN TETH


More esthetics than acrylic resin teeth.



Strength more than acrylic teeth .


...


Clicking sound.



Difficult to trim & adjust so cannot be used in inadequate interarch
space.



Mechanical bonding ...
• THE INTERCHANGEABLE FACING








It is a strongest type of anterior teeth replacements.
Indicated in
Single toot...


Advantages



When contours of the RAR altered by resorption the
interchangeable facings can be refitted.



Disadvan...
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•THE POST OR PRESSED ON TOOTH


Esthetics better than the Interchangeable facings.



Strength better than denture tooth...
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• METAL TOOTH


It is the tooth of choice for posterior tooth replacement.



Strength more than any other prosthetic to...
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

Gold occlusal surfaces.



Amalgam occlusal
surfaces

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• THE SELF CLEANSING PONTIC


The self cleansing occlusal surfaces which
is an integral part of the metal frame work
thus...
•SELECTION OF ANTERIOR TEETH FOR REMOVABLE
PARTIAL DENTURES


FACTORS TO BE CONSIERED



Size



Shape & form



Textu...
•DENTOGENIC CONCEPT
 Dentogenics is the art, practice & technique of creating the illusion
of natural teeth in artificial...


Consideration of age factors in prostodontics is to maintain the
conformity between the restoration & patients physiolo...
• SIZE OF THE TOOTH


Measuring the dimensions of the corresponding tooth on the
opposite side of the arch.



Pre – ext...
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• LENGTH OF THE TOOTH










Visibility of incisal edges & high lip line guide in the selection of
the length of ...
Length of C.I = Chin to hair line distance / 16
 By Dr. M.M.House


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• WIDTH


METHODS



1) Canine eminences
Line marked on the distal aspect of canine eminence on
the cast gives the mesio...
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

3) Cranial circumference
The horizontal circumference of the cranium about plane passing through
glabella & most promin...
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

Lateral surface of nose
The line passing from the lateral surface nose, through the center
brow line. Lateral aspect of...
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• SHAPE OF THE TEETH


The shape of the teeth should be in
harmony with the patients face.



J. Leon Williams – the sha...
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• SHADE SELECTION


Artificial tooth shades should be selected according to the
physiological color changes seen in progr...
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•TEXTURE OF THE TOOTH


The artificial teeth should incorporate the features like
imbrication lines, wear facets, hypopla...
SELECTION OF THE POSTERIOR TEETH
 The

form of the posterior teeth is important for the
preservation & maintenance of the...










SIZE:
MESIODISAL DIMENSION :
In tooth supported RPD the space between the distal surface of
mesial abutme...


BUCCOLINGUAL DIMENSION.



The BL space available for artificial teeth is limited by the cheek &
tongue tissues , load...
•FORM OF POSTRIOR TEEH


Determined by the cuspal inclines & arrangement of remaining
natural teeth.



Deep over bite c...
 SHADE

SELECTION
 In harmony with the remaining natural teeth .

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

METHODS OF ATTACHING THE ARTIFICIAL
TEETH TO THE DENTURE BASE

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Porcelain or Resin tube teeth & Facings cemented
directly to Metal Bases


Teeth are altered & set prior to
completion of...
Pressing on a Resin tooth


Modification..



Teeth is selected & labial index of the position of the
teeth is made.


...









Resin Tube or side groove teeth is selected
before waxing the denture frame work.
Hole is drilled on the rid...
RESIN TEETH PROCESSED DIRECTLY TO
METAL BASES



The recess is carved in the wax pattern.
Occlusal relationships establi...


Braided helical Post.



Posterior tube teeth.

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•REVIEW OF LITERATURE
A study was conducted by Anthony & Peyton (1962) He
compared the dimensional accuracy of self cure &...
A study was conducted by Donald , Lundquist in (1963)
He compared the accuracy of fit of denture bases made
of PMMA & Al.
...


A study was conducted by Anthony De Furio and Daniel H. Gehl
(1970) to determine the amount of force required to dislod...


A study was conducted by Frank E. Pulskamp in (1979)
He compared the two dimensional accuracy of Type iv
Gold alloy, Ni...
A study which was conducted in dept of prosthodontics by Dr.Gautam
Shetty under the guidance of DR. N.P.PATIL Sir The main...
RESULTS :


The results indicated the accuracy of fit of aluminium was better
than base metal alloy and superior than acr...
•SUMMARY & CONCLUSION

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REFERENCES


Applegate The partial denture base. J.P.D:1955:5:636:648.



Anthony & Peyton Dimensional accuracy of vario...


Frush How dentogenics interpretes the personality factor,
J.P.D:1956:441
Frush How dentogenics interpretes the sex fact...
Thank you
For more details please visit
www.indiandentalacademy.com

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Selection of denture base and teeth for rpd /certified fixed orthodontic courses by Indian dental academy

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The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.

Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078

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Selection of denture base and teeth for rpd /certified fixed orthodontic courses by Indian dental academy

  1. 1. SELECTION OF DENTURE BASE AND TEETH FOR REMOVABLE PARTIAL DENTURE INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  2. 2. • CONTENTS           Introduction Definition Functions of denture base Ideal requirements of denture base materials . Denture base materials used in fabrication of RPD. Denture Base resins. Advantages & Disadvantages Metallic denture base materials Advantages & disadvantages Fabrication of distal extension denture base www.indiandentalacademy.com
  3. 3.          Attaching Resin denture base to major connector Teeth selection Different artificial teeth Anterior teeth selection Posterior teeth selection Attaching teeth to denture base Review of literature Summary & Conclusion References. www.indiandentalacademy.com
  4. 4. • INTRODUCTION www.indiandentalacademy.com
  5. 5.  DENTURE BASE  The part of a denture that rests on the foundation tissues and to which teeth are attached. www.indiandentalacademy.com
  6. 6. •FUNCTIONS OF TOOTH SUPPORTED DENTURE BASE  Provide desirable esthetics.  Support the artifial tooth .  Prevent vertical & horizontal migration of remaining natural teeth.  Eliminate undesirable food entrapment.  Stimulate the underlying tissues. www.indiandentalacademy.com
  7. 7. • FUCTIONS OF DISTAL EXTENSION DENTURE BASE  Contributes to the support of the denture & improves stability of the prosthesis .  Esthetics by attaching the teeth & restoring the lost facial contours.  Stimulation of the underlying tissues.  Cleanliness maintenance.  Secondary retention by intimate contact between the denture base & the major connector with the underlying tissues www.indiandentalacademy.com
  8. 8. •IDEAL REQUIREMENTS OF  Bio- compatible.  Accurately adapt to the underlying tissues  Adequate Physical & Mechanical properties  -Sufficient strength to resist distortion & fracture -Dimensional stability -Low specific gravity, -Good thermal conductivity -Easy to finishing & polishing -Should not absorb oral fluids -In soluble in oral fluids. www.indiandentalacademy.com
  9. 9.  Ease of fabrication & repair.  Potential for future relining , rebasing.  Esthetically acceptable ,color stability.  Odourless.  tasteless  Easy to clean the prosthesis.  Long shelf life.  Cost effective. www.indiandentalacademy.com
  10. 10. • DENTURE BASE MATERIALS  Acrylic resin  Metallic www.indiandentalacademy.com
  11. 11. •HEAT ACTIVATED DENTURE BASE RESIN  COMPOSITION:  POWDER 1) Poly(methyl methacrylate) 2) Initiator- Benzoyl peroxide-0.5- 1.5% 3)Plasticizer- Dibutyl pthalate 4) Pigments 5) Opacifiers 6)Inorganic particles- glass fibers & alumina. www.indiandentalacademy.com
  12. 12.  LIQUID  Non polymerized methyl methacrylate  Inhibitor – Hydroquinone 0.003%-0.1%.  Cross linking agent – Glycol dimethacrylate-1 to 2% by volume. www.indiandentalacademy.com
  13. 13.  HIGH IMPACT STRENGTH MATERIALS  Reinforced with butadiene styrene rubber  The rubber particles are grafted to methyl methacrylate to bond to the acrylic matrix  POUR TYPE RESIN Composition similar particle size smaller   www.indiandentalacademy.com
  14. 14.  RAPID HEAT POLYMERIZED RESIN  Altered initiator system  LIGHT ACTIVATED  Urethane dimethacrylate matrix with acrylic copolymer  Microfine silica fillers   Photo initiator - Comphorquinone Polymerized with a visible light of 400 to 500 nm www.indiandentalacademy.com
  15. 15. FIBER –REINFORCED POLYMER  Glass, carbon/graphite, aramid and ultrahigh molecular wt polyethylene have been used as fiber reinforcing agents.  Metal wires like graphite has minimal esthetic qualities.  Fibers are stronger than matrix polymer thus their inclusion strengthens the composite structure.  The reinforcing agent can be in the form of unidirectional, straight www.indiandentalacademy.com fiber or multidirectional weaves.
  16. 16. •MECHANICAL PROPERTIES  PMMA&PVA posses adequate tensile & compressive strength .  Transverse strength is the combination of tensile & compressive strength proportional limit, elastic modulus .  PVA has 7to 10%of Elongation ,is an indication of toughness & permit larger deformation .  Proportional limit should be sufficiently high to withstand masticatory forces. www.indiandentalacademy.com
  17. 17.  Impact strength –. Rubber reinforced acrylic more impact strength.  Rubber reinforced acrylic resin possesses adequate fatigue strength to withstand the smaller cyclic stresses during mastication.  Fracture toughness of rapid heat cure resin is better than conventional & high impact resin.  Hardness KHN of denture base acrylic is low so care should be taken while polishing, cleaning. www.indiandentalacademy.com
  18. 18. www.indiandentalacademy.com
  19. 19. www.indiandentalacademy.com
  20. 20. • ADVANTAGES  Easy adjust & polish.  Reling & rebasing is possible .  The weight & bulk is more than cast alloys.  Denture base contours for functional tongue & cheek movements.  In mandibular arch weight of the denture contributes for retention.  Esthetics, tinting..  Processing  Cost www.indiandentalacademy.com
  21. 21. • DIS ADVANTAGES  Adaptation not as accurate as cast metal alloy.  Abrasion resistance..  Acrylic resin bases tend to accumulate mucinous deposits  So meticulous cleanliness maintenance required.  Thermal conductivity  Weight & Bulk  It should be min. 2mm in thickness to obtain adequate rigidity & strength . www.indiandentalacademy.com
  22. 22. •METALLIC DENTURE BASE MATERALS REMOVABLE PARTIAL DENTURE  High Noble casting alloys- Au- Ag- Cu -Pd  Predominantly base metal alloys * Co-Cr-Mo * Co- Cr –W * Ni-Cr –Mo * Ni-Cr –Mo-Be * Cp-Ti * Ti-Al-V www.indiandentalacademy.com
  23. 23. •  As early as 1949 it was estimated that nearly 80% of all partial denture appliances were cast from Co-Cr alloys.  Principle elements –Cr, Co, Ni -82 to 92%.  COMPO SITION :  COBALT-CHROMIUM -ALLOYS - Cobalt- 60%   - Chromium -25% to 30% OTHER COMPONENTS : Mo,Al,W,Fe,Ga, Cu, Si, C, Pl. www.indiandentalacademy.com
  24. 24.     COBALT-CHROMIUM-NICKEL - Co-50% - Cr-25% - Ni-19% Other constituents - Mo-3.7% - C -0.2% NICKEL CHROMIUM- MOLYBDENUM ALLOYS : - Ni - 70% - Cr - 16% Other constituents - Al –2% - Be –0.5% www.indiandentalacademy.com - Mo,W, Mg, Co, Si, C.
  25. 25.  Chromium : Tarnish and corrosion resistance and stain less properties.  Cobalt and nickel : In general cobalt and nickel are interchangeable .  Cobalt increases the elastic modulus ,strength and hardness more than Nickel does. www.indiandentalacademy.com
  26. 26.   OTHER ALLOYING COMPONENTS : Carbon : increases the hardness of Co based alloys.  Molybdenum : (3% to 6% ) Contributes to the strength of the alloy.  Aluminium : Forms a compound with Ni ,which increases the tensile and the yield strength of the alloys. www.indiandentalacademy.com
  27. 27.  Berylium : About 1% lowers the fusion temperature range of the alloy by about 100 degrees C.  Silicone and Manganese : Increase the fluidity and castability of these alloys.  Nitrogen : If present contributes to the brittle qualities of these alloys . www.indiandentalacademy.com
  28. 28. •TITANIUM ALLOYS     High purity titanium (99 wt %) with O,C ,N,H atoms dissolved interstitially. It undergoes an allotropic transformation from hexagonal to body centered crystal structure when the temperature is raised to 882 +/ 2 degree. 4 types – Alpha - Near alpha -Alpha – Beta -Beta Cp Ti available in 4 different grades (ASTM) www.indiandentalacademy.com
  29. 29.  Titanium alloy- Ti- 6V – 4Al  Vanadium is the beta phase stabilizer with the BCC structure.  Al alpha phase stabilizer  Most commonly used is alpha – beta alloy. [strength > Cp Ti.] www.indiandentalacademy.com
  30. 30. • TYPE IV GOLD ALLOY           Composition : Au - 69% Ag – 12.5% Cu -10% Pd – 3.5% Pt – 3% Zn,Sn,Fe,In, Ga for balace. ALLUMINIUM ALLOY Al – 99.95 wt % Mg – 3.5% www.indiandentalacademy.com
  31. 31. MECHANICAL PROPERTIES Metal Type Yeild Strength (Mpa/Ksi) Tensile Strength (Mpa/Ksi) Elongation (%) Hardness (HV) Elastic Modulus (GPa/Ksi x 103 ) Co- Cr (A ) 710/103 870/120 1.6 432 224/32.4 Ni – Cr (B) 690/100 800/116 3.8 300 182/26.4 Co – Cr – Ni (c) 470/68 685/99 8.0 264 198/28.7 Fe – Cr ( D) 703/102 841/122 9 309 202/29.3 Type IV Gold 493/71.5 776/112 7 264 90/13 CP Ti 344/50 345/50 13 210 103/14.9 Ti – 6V- 4 Al 870/126 925/134 5 320 117/17 www.indiandentalacademy.com
  32. 32. www.indiandentalacademy.com
  33. 33. ADVANTAGES OF METALLIC DENTURE BASE  Accurate adaptation & permanence of the form  Abrasion Resistance.  Comparative tissue response -Inherent cleanliness -greater density & bacteriostatic activity contributed by the ionization & oxidation of metal base. www.indiandentalacademy.com
  34. 34.  Thermal conductivity .  Better patient acceptance.  Weight & Bulk  Metal alloys can be casted much thinner..  Maintains & prolongs the health of supporting tissues. www.indiandentalacademy.com
  35. 35. DIS ADVANTAGES  Relining & rebasing difficult.  Difficult to adjust.  It cannot be used whenever restoring the normal facial contours is required for esthetics.  Special equipment required.  More expensive. www.indiandentalacademy.com
  36. 36.  INDICATIONS:  1) Risk of fracture of resin denture base.  2)RAR atrophy  2) More room for the tongue functioning is required.  3) Patient allergic to resin.  4) Satisfactorily healed ridges. www.indiandentalacademy.com
  37. 37. • THE METAL- ACRYLIC RESIN BASE  Consists of cast metal base that fits the RAR & acrylic resin attached to it to retain the teeth. www.indiandentalacademy.com
  38. 38. •FABRICATION OF DENTURE BASE IN DISTAL EXTENTION RPD  Distal extension RPD depends…  Extensions of the denture base  Kaire has shown that maximum coverage of denture bearing areas with large wide denture base is of utmost importance for with standing the vertical & horizontal stresses. www.indiandentalacademy.com
  39. 39. •SELECTIVE PRESSURE IMPRESSION METHOD By this method the soft tisuses over the primary supporting areas are recorded to provide support to the denture base under functional load.  Denture base closely adapted in the region of buccal shelf area .  lightly adapted to the crest of the ridge.  www.indiandentalacademy.com
  40. 40. www.indiandentalacademy.com
  41. 41. www.indiandentalacademy.com
  42. 42. •METHODS OF ATTACHING THE DENTURE BASE  Minor connector joins the denture base to the major connector.  Relief of at least 20 guage is provided beneath the retentive frame work for the acrylic to flow.  Should not interfere with teeth arrangement.  Any junction of acrylic resin with metal should be at an undercut finishing line. www.indiandentalacademy.com
  43. 43. •TYPES OF MINOR CONNECTORS  1) Open construction 2) Mesh construction  3) Bead, nail head & wire constructions  www.indiandentalacademy.com
  44. 44. CHEMICAL BONDING  Direct bonding of acrylic resin to metal framework.  Sections of metal frame work meant for supporting the replacement teeth is roughened with abrasives & treated with vaporized silica coating.  Acrylic bonding agent is applied.  Thin film of acrylic resin applied to act as substrate for teeth replacement or acrylic resin tissues replacement www.indiandentalacademy.com
  45. 45.   Tribochemical coating Method for fusing microscopic layer of ceramic to metal.  Sandblasting the metal framework with special silica particle material .  Silica is attached to the framework by impact.  Silane is added to this ceramic like film to form chemical bond between silicate layer & acrylic resin.  Denture base acrylic resins formulate with 4-META provide mechanism of bonding acrylic resin to metal. www.indiandentalacademy.com
  46. 46. www.indiandentalacademy.com
  47. 47. •SELECTION OF THE PROSTHETIC TEETH  Teeth replacement is important to reestablish the lost facial contours, phonetics, masticatory function. www.indiandentalacademy.com
  48. 48. • IDEAL PROSTHETIC TOOTH SHOULD SATISFY FOLLOWING REQUIREMNT  Pleasing appearance to satisfy the esthetic requirement.  Easily adaptable to any edentulous space.  Easy for attaching to the prosthesis.  Easy to modify the shape & size as per requirement & repolish restore the original polish.  Color stability. www.indiandentalacademy.com
  49. 49.  Resistance to blanching, distortion ,crazing.  It should have enough strength to bear occlusal load.  Adequate resistance to wear.  Capable of articulating with teeth of any occlusal pattern or material without causing adverse effect to either. www.indiandentalacademy.com
  50. 50. • TYPE OF ARTIFICIAL TEETH  Acrylic resin teeth  Porcelain teeth  Metal tooth  Acrylic resin teeth with occlusal restorations  Custom denture tooth. www.indiandentalacademy.com
  51. 51. •ACRYLIC RESIN TEETH  Strength adequate to withstand the occlusal load.  Chemical bonding with acrylic denture base.  Low abrasion resistance  Absorbs stain.  Impact resistance greater than porcelain.  Shape & size can be modified. www.indiandentalacademy.com
  52. 52.  Easy to polish.  Dose not cause the wear of the opposing natural teeth or gold restorations.  Low heat distortion temperature .  Cold flow or permanent deformation under pressure below their elastic limit. www.indiandentalacademy.com
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  54. 54. • CHARECTERISTICS OF PORCELAIN TETH  More esthetics than acrylic resin teeth.  Strength more than acrylic teeth .  Brittle chips off or fractures easily  Good abrasion resistance  It can cause wear of the opposing natural teeth or gold restorations.  Impervious to stain. www.indiandentalacademy.com
  55. 55.  Clicking sound.  Difficult to trim & adjust so cannot be used in inadequate interarch space.  Mechanical bonding with the acrylic denture base so percolation may occur  High heat distortion temperature .  No permanent deformation under forces of mastication. www.indiandentalacademy.com
  56. 56. • THE INTERCHANGEABLE FACING       It is a strongest type of anterior teeth replacements. Indicated in Single tooth replacements preferred especially in anterior region In severely decreased inter ridge space. - Deep bite. - Bulbous alveolar ridge such that the retention latice work of the metal frame work is restricted. When more strength is required in anterior teeth replacement. Sometimes used for replacing maxillary I premolar. www.indiandentalacademy.com
  57. 57.  Advantages  When contours of the RAR altered by resorption the interchangeable facings can be refitted.  Disadvantages  Esthetically not good. www.indiandentalacademy.com
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  59. 59. •THE POST OR PRESSED ON TOOTH  Esthetics better than the Interchangeable facings.  Strength better than denture tooth but less than interchangeable facing.  Requires adequate amount of interarch space .  Most commonly used to replace maxillary canine. www.indiandentalacademy.com
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  61. 61. • METAL TOOTH  It is the tooth of choice for posterior tooth replacement.  Strength more than any other prosthetic tooth.  The frame work is of the Co- Cr then tooth should not be occluded heavily with the opposing gold restoration .  Indicated in  Edentulous space measuring about 3to8 mm. Decreased mesio distal width by mesial drifting of 2nd molar . www.indiandentalacademy.com
  62. 62. www.indiandentalacademy.com
  63. 63.  Gold occlusal surfaces.  Amalgam occlusal surfaces www.indiandentalacademy.com
  64. 64. • THE SELF CLEANSING PONTIC  The self cleansing occlusal surfaces which is an integral part of the metal frame work thus the potential areas of food entrapment are eliminated & permitting saliva to flow under & around pontic.  Used to replace the single posterior tooth with extensive alveolar ridge atrophy.  When the adjoining teeth have drifted , rotated. www.indiandentalacademy.com
  65. 65. •SELECTION OF ANTERIOR TEETH FOR REMOVABLE PARTIAL DENTURES  FACTORS TO BE CONSIERED  Size  Shape & form  Texture  Color  Material www.indiandentalacademy.com
  66. 66. •DENTOGENIC CONCEPT  Dentogenics is the art, practice & technique of creating the illusion of natural teeth in artificial denture & is based on the elementary factors suggested by the sex, personality & age of the patient.  Considering the sex factor - Feminine characteristics select the mold that is more rounded & incisal edges altered by grinding procedures which gives more softer appearance. - Masculine characteristics select mold , followed by grinding of incisal edges to make more squarish. www.indiandentalacademy.com
  67. 67.  Consideration of age factors in prostodontics is to maintain the conformity between the restoration & patients physiological age.  As age advances natural teeth show wearing & similar aging effects are produced in artificial teeth by characterization.  Considering the personality factors  Personality spectrum – Delicate, Medium pleasing , Vigorous .  The mold should be in harmony with the personality of the individual.  Age, sex & personality are inseparable & interdependent. www.indiandentalacademy.com
  68. 68. • SIZE OF THE TOOTH  Measuring the dimensions of the corresponding tooth on the opposite side of the arch.  Pre – extraction records – Photographs, Study casts, radiographs.  Extracted teeth of the patient.  Edentulous space  In multiple anterior teeth replacement the space is measured.  Increased space in edentulous area as seen in patients with large diastema between the central incisors. Then two central incisors are placed with overlapping the teeth or reshaping it as lateral incisor. www.indiandentalacademy.com
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  70. 70. • LENGTH OF THE TOOTH       Visibility of incisal edges & high lip line guide in the selection of the length of the anterior tooth . Visibility of the upper anterior depends on 1) Age -Young patients 2 to 3 mm of upper central incisor may be visible . -Elderly – fraction of a mm of tooth. 2)Length of upper lip - Short upper lip- half the length of crown of the central incisor may be visible. 3) Over bite – More of the upper anterior teeth may be visible. www.indiandentalacademy.com High lip line – the maximum excursion of upper lip in function.
  71. 71. Length of C.I = Chin to hair line distance / 16  By Dr. M.M.House  www.indiandentalacademy.com
  72. 72. • WIDTH  METHODS  1) Canine eminences Line marked on the distal aspect of canine eminence on the cast gives the mesio –distal width of upper anterior teeth  2)Bizygomatic width Breadth of all upper anterior teeth Bizygomatic width / 3.3 Width of upper C.I = Bizygomatic width / 16 www.indiandentalacademy.com
  73. 73. www.indiandentalacademy.com
  74. 74.  3) Cranial circumference The horizontal circumference of the cranium about plane passing through glabella & most prominent point on the occipital bone is said to be 10 times the width of six anterior teeth  Corner of the mouth. The distal surface of the natural upper canine is positioned at the corner of relaxed mouth ..  Width of the nose The parallel lines extended from the lateral surface of ala of nose onto the properly contoured upper occlusal rim will give an indication of position of cusp tip of upper canine teeth . www.indiandentalacademy.com
  75. 75. www.indiandentalacademy.com
  76. 76.  Lateral surface of nose The line passing from the lateral surface nose, through the center brow line. Lateral aspect of ala & extended on to the occlusal rim , gives an indication of the position of distal aspect of canine tooth.  Incisive papilla Line parallel to coronal plane & passing through the incisive papilla passes through the cusp tips of cuspid. www.indiandentalacademy.com
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  78. 78. • SHAPE OF THE TEETH  The shape of the teeth should be in harmony with the patients face.  J. Leon Williams – the shape of crown of upper central incisor corresponded to the outline form of the face.  Classified Face form – Square _Tapering _Ovoid www.indiandentalacademy.com
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  80. 80. • SHADE SELECTION  Artificial tooth shades should be selected according to the physiological color changes seen in progressively aging , undiseased tooth.  Methods - The tentative selection of the anterior teeth is arranged on a plastic tooth selector & held on the side of the patient’s face -Under the lip with more exposed tooth to observe the size in relation to the patient’s face. -The ‘ SQUINT TEST’. www.indiandentalacademy.com
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  82. 82. •TEXTURE OF THE TOOTH  The artificial teeth should incorporate the features like imbrication lines, wear facets, hypoplastic areas to harmonize with the adjacent natural teeth. www.indiandentalacademy.com
  83. 83. SELECTION OF THE POSTERIOR TEETH  The form of the posterior teeth is important for the preservation & maintenance of the health of the residual alveolar ridges.  www.indiandentalacademy.com
  84. 84.        SIZE: MESIODISAL DIMENSION : In tooth supported RPD the space between the distal surface of mesial abutment & mesial surface of the distal abutment teeth should be considered. In distal extension RPD the space between the canine & the anterior end of the retromolar pad is considered. OCCLSOGINGIVAL DIMENSION: Available inter arch space determines the length. Esthetics should be in harmony with adjacent natural teeth. www.indiandentalacademy.com
  85. 85.  BUCCOLINGUAL DIMENSION.  The BL space available for artificial teeth is limited by the cheek & tongue tissues , load bearing capacity of the supporting tissues.  Relatively narrow in BL direction are indicated to enhance the sloping form of the flanges , permit surrounding tissues to function to maintain the stability of the denture.  Narrow occlusal surfaces with proper escape ways for food thought to direct the less force during function to supporting structure www.indiandentalacademy.com
  86. 86. •FORM OF POSTRIOR TEEH  Determined by the cuspal inclines & arrangement of remaining natural teeth.  Deep over bite cases the high cusped teeth should be used to achieve occlusal balance.  In RAR atrophy the non anatomic teeth are used . www.indiandentalacademy.com
  87. 87.  SHADE SELECTION  In harmony with the remaining natural teeth . www.indiandentalacademy.com
  88. 88.  METHODS OF ATTACHING THE ARTIFICIAL TEETH TO THE DENTURE BASE www.indiandentalacademy.com
  89. 89. Porcelain or Resin tube teeth & Facings cemented directly to Metal Bases  Teeth are altered & set prior to completion of frame work.  Disadvantages  Difficulty in obtaining the satisfactory occlusion.  Lack of adequate contours for functional tongue & cheek contact.  Unaesthetic display of metal at the gingival margin. www.indiandentalacademy.com
  90. 90. Pressing on a Resin tooth  Modification..  Teeth is selected & labial index of the position of the teeth is made.  Post hole prepared on lingual portion.  Tooth attached with acrylic resin of the same shade. www.indiandentalacademy.com
  91. 91.      Resin Tube or side groove teeth is selected before waxing the denture frame work. Hole is drilled on the ridge lap area. The tooth is ground to fit the ridge with sufficient clearance for the metal base. 45 degree bevel is placed around the base of tooth to accommodate the boxing of metal. Lingual collar is created. www.indiandentalacademy.com
  92. 92. RESIN TEETH PROCESSED DIRECTLY TO METAL BASES   The recess is carved in the wax pattern. Occlusal relationships established  The teeth is carved & processed in acrylic resin of the proper shade.  Advantages  Better attachment to the metal base.  Unusually long, short, narrow, wide teeth may be fabricated. www.indiandentalacademy.com
  93. 93.  Braided helical Post.  Posterior tube teeth. www.indiandentalacademy.com
  94. 94. •REVIEW OF LITERATURE A study was conducted by Anthony & Peyton (1962) He compared the dimensional accuracy of self cure & heat cure acrylic resin , Cr- Co alloy .  He concluded that self cure acrylic resin dentures were of accurate fit followed by heat cure, Cr- Co . Because of the fewer processing strains.  www.indiandentalacademy.com
  95. 95. A study was conducted by Donald , Lundquist in (1963) He compared the accuracy of fit of denture bases made of PMMA & Al.  He concluded that the fit of accuracy of cast Al alloy dentures were better than the PMMA.  www.indiandentalacademy.com
  96. 96.  A study was conducted by Anthony De Furio and Daniel H. Gehl (1970) to determine the amount of force required to dislodge maxillary dentures made from Al ,Au alloy and acrylic resin.  He concluded that the chrome cobalt and Al alloy bases gave retention values which were significantly higher than those obtained with the acrylic resins and gold alloy bases www.indiandentalacademy.com
  97. 97.  A study was conducted by Frank E. Pulskamp in (1979) He compared the two dimensional accuracy of Type iv Gold alloy, Ni-Cr, Co-Cr alloys.  He concluded that Type iv gold alloy showed least cross arch & antero posterior expansion than Co-Cr. www.indiandentalacademy.com
  98. 98. A study which was conducted in dept of prosthodontics by Dr.Gautam Shetty under the guidance of DR. N.P.PATIL Sir The main objective of the study were : 1. To compare the fit of Al alloy (7010)denture base and base metal alloy denture base. with acrylic 2. To study the effect of anodization and electroplating on the resistance to corrosion. 3. To compare the flexure strength of aluminum alloy with that of resin and base metal alloy . www.indiandentalacademy.com
  99. 99. RESULTS :  The results indicated the accuracy of fit of aluminium was better than base metal alloy and superior than acrylic resin  Anodized Al showed better resistance to corrosion resistance than that electroplated and that without any surface treatment. www.indiandentalacademy.com
  100. 100. •SUMMARY & CONCLUSION www.indiandentalacademy.com
  101. 101. REFERENCES  Applegate The partial denture base. J.P.D:1955:5:636:648.  Anthony & Peyton Dimensional accuracy of various denture base materials J.P.D: 1962:12:61-81.  Craig’s Restorative dental materials ,11th edition.  David Watt, MacGregor’s Designing Partial dentures.  Donald An alluminium alloy denture base material. J.P.D : 1963:13:1:102.  Grant & Jhonson’s Removable denture prosthodontics, 2nd edition.  Earnest Miller’s Removable prosthodontics 2nd edition.  Frush ,Fisher, Ronald introduction to Dentogenic Restoration ,J.P.D www.indiandentalacademy.com 1955:586:595
  102. 102.  Frush How dentogenics interpretes the personality factor, J.P.D:1956:441 Frush How dentogenics interpretes the sex factor, J.P.D :1956:160  Frush, Fisher Age factor in Dentogenics 1957:7:5  Frush Dentogenic s Its practical application. 1959:9:6:914.  Jhon Cornell Physical properties of denture bae materials J.P.D :  1960 :10:516.  McCracken’s Removable partial prosthodontics, 11th edition.  Philip’s Science of Dental Materials, 11th edition.  Stewart’s Clinical Removable partial prosthodontics, 3rd edition. www.indiandentalacademy.com
  103. 103. Thank you For more details please visit www.indiandentalacademy.com www.indiandentalacademy.com

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