Implant supported overdenture, overdenture, implant occlusion, steps, seminar

1. IMPLANT
SUPPORTED
OVERDENTURE
GUIDED BY
DR KHINNAVAR POONAM K
PRESENTED BY
ADITI SHREYA
3rd
YEAR POST GRADUATE

2. CONTENTS
 Introduction
 Definitions
 Prosthetic Options
 Advantages Of OD
 Disadvantages Of OD
 Implant OD V/S Fixed
Prosthesis Advantages
 Prosthesis Movement
 OD Attachments
 OD Treatment Options-
Mandible/Maxilla
 All On 4 Implants
 Review Of Literature
 Conclusion
 References

3. INTRODUCTION
 The consequences of total tooth loss

4. DEFINITION
? According to GPT 9:-
Overdenture : Any removable dental prosthesis that covers and rests
on one or more remaining natural teeth, the roots of natural teeth,
and/or dental implants; a dental prosthesis that covers and is
partially supported by natural teeth, natural tooth roots, and/or
dental implants.
? An overdenture is defined as a removable prosthesis
that covers the entire occlusal surface of a root or implant
( Harold W Preiskel)

5. FP 1
Fixed prosthesis, replaces
only the crown, looks like
a natural tooth.
FP 2
Fixed
prosthesis, replaces the
crown and a portion of
the root
FP 3
Fixed
prosthesis, replaces missing
crown and gingival color and
portion of the edentulous site.
PROSTHETIC OPTIONS

6. RP 4
Removable prosthesis, over
denture supported completely
by implant.
RP 5
Removable prosthesis,
overdenture supported by both
soft tissue and implant

7. ADVANTAGES OF IMPLANT
SUPPORTED PROSTHESIS
 Minimum/ prevents anterior bone loss
 Improved esthetics
 Improved stability
 Improved occlusion
 Decrease in soft tissue abrasions
 Improved chewing efficiency and force
 Improved retention
 Improved support
 Improved speech
 Reduced prosthesis size
 Improved maxillofacial prostheses

8. DISADVANTAGES OF IMPLANT
SUPPORTED PROSTHESIS
 psychological
 Greater abutment crown height space is required.
 Long term maintenance
 Continued posterior bone loss
 Food impaction
 Movement (RP-5)

10. CLASSIFICATION OF
PROSTHESIS MOVEMENT (Misch 1985)
PM0 No movement of prosthesis, requires implant support similar
to fixed prosthesis
PM2 Prosthesis with hinge motion
PM3 Prosthesis with hinge and apical motion
PM4 Allows movement in four directions
PM6 All ranges of prosthesis movement

11. OVERDENTURE OPTIONS

14. OVERDENTURE OPTION 1
Patient Selection Criteria
• Opposing a maxillary full denture
• Anatomical conditions are good to excellent
• Posterior ridge form is an inverted U shape.
• Patient’s needs and desires are minimal
• Edentulous ridge, with a tapered dentate arch form
• Cost is the primary factor.
• Additional implants will be inserted within 3 years.

15. A E
B D

17. ADVANTAGES
 Reduced cost.
 Hygiene procedures also are facilitated
DISADVANTAGES
 Relatively poor implant support and stability
 Future bone loss is not reduced
 Increase in prosthetic maintenance appointments
 Wear of attachments

18. OVERDENTURE OPTION 2
PATIENT SELECTION CRITERIA
 Opposing arch is a maxillary denture.
 Anatomical conditions are good to excellent
 Posterior ridge forms an inverted U shape.
 Patient’s need and desires are minimal
 Patient can afford new prosthesis and connecting bar.
 Additional implants will not be inserted for more than 3 years.
 Low patient force factors (e.g., parafunction)

20. Disadvantages of A and E Splinted Implants

21. OVERDENTURE OPTION 3
PATIENT SELECTION CRITERIA
 Opposing arch is a maxillary denture
 Anatomical conditions moderate to
excellent
 Posterior ridge forms inverted U shape
 Patient’s needs and desires require
improved retention, support, and
stability
 Cost a moderate factor
 Patient may have moderate force factors

23. Advantages of Splinted A, C, and E Implants
 Six times less bar flexure compared with A and E positions
 Less screw loosening
 Less metal flexure
 Three implant abutments
 Less stress to each implant compared with A and E implants
 Greater surface area
 More implants
 Greater anteroposterior distance

24. OVERDENTURE OPTION 4
 Four implants are placed in the A, B, D, and E positions.
 Patient has opposing maxillary teeth or c–h anterior
bone volume with CHS greater than 15 mm.
 Distal cantilever up to 10 mm on each side if the stress
factors are low.

25. PATIENT SELECTION CRITERIA
 Moderate to severe problems with traditional dentures
 Needs or desires are demanding
 Need to decrease bulk of prosthesis
 Inability to wear traditional prostheses
 Desire to abate posterior bone loss
 Unfavourable anatomy for complete dentures
 Problems with function and stability
 Posterior sore spots
 Opposing natural teeth
 C–h bone volume
 Unfavourable force

26. OVERDENTURE OPTION 5
 Five implants are inserted in the A, B, C, D, and E positions.
 The superstructure is usually cantilevered distally up to two times
the A-P spread and averages 15 mm, which places it under the
first molar area

27. PATIENT SELECTION CRITERIA
 Moderate to severe problems with
traditional dentures
 Needs or desires are demanding
 Need to decrease bulk of
prosthesis
 Inability to wear traditional
prostheses
 Desire to abate posterior bone loss
 Unfavorable anatomy for
complete dentures
 Problems with function and
stability
 Posterior sore spots
 Moderate to poor posterior
anatomy
 Lack of retention and stability
 Soft tissue abrasion
 Speech difficulties
 More demanding patient type

29. MAXILLARY OVERDENTURE
 Only two treatment options are available.
 Independent implants are not an option because bone quality and
force direction are severely compromised.
 Cantilever bars are usually not recommended
 The crown height space:
 15 mm-anterior space
 12 mm- posterior space

30. ADVANTAGES OF RP4 MAX OD
 Ability to provide a flange for maxillary lip support
 The improved sulcular hygiene
 Reduced laboratory fee

31. TREATMENT OPTIONS
RP-5 prosthesis: four to six implants in three to five arch positions
RP-4 prosthesis: six to 10 implants in all five arch positions

32. OPTION 1: MAXILLARY RP-5 IMPLANT
OVERDENTURE
 Four to six implants supporting a RP-5
prosthesis, of which three are usually
positioned in the premaxilla.
 Implants should be at least 9 mm in length
and 3.5 mm in body diameter.

33.  Six implants are often indicated for a RP-5 prosthesis when force
factors are greater.
 The implants are always splinted together with a rigid bar.

34. Advantages
 Retention and stability from the implants.
 Posterior support is obtained from the soft tissue.
 Maintenance of the premaxillary bone because of the implant
stimulation.

35. OPTION 2: MAXILLARY RP-4 IMPLANT
OD
 6 to 10 implants, which is rigid during
function.
 Bilateral canines and distal half of the first
molar positions
 Additional posterior implants are located
bilaterally in the pre- molar position,
preferably the second premolar site.
 In addition, at least one anterior implant
between the canines often is the anterior
implant often may be placed in the incisive
canal.

36.  The six to 10 implants are splinted together around the arch with
a rigid bar.
 Four or more attachments are usually positioned around the arch.

37. ALL ON 4 IMPLANTS (Paulo Malo)
 Allows the rehabilitation of edentulous jaws
without bone graft in one surgical step
through the placement of four implants,
optimizing the available bone.

38. Advantages
 No anatomical structures interference.
 Angled implant reduces cantilevering.
 Immediately provisional bridge can be fabricated
 Teeth in a day
 No ill fitting dentures any more
 Feel and function just like natural teeth

39. Disadvantages
 Free hand arbitrary surgical placement of implant is not always
possible
 Length of cantilever in the prosthesis cannot be extended beyond
the limit.
 It is very technique sensitive and requires elaborate pre-surgical
preparation

40. ALL ON 6 DENTAL IMPLANTS
 The standard of care for full arch rehabilitation with dental
implants when the quality and the quantity of the alveolar jaw
bone is excellent.

41. ATTACHMENTS USED TO RETAIN
OVERDENTURE (Since 1960s)
 Pillars of implant supported OD.

42. According to retentive means
 Frictional
 Mechanical
 combination
 Magnetic attachments
Attachments based on resiliency
 Rigid non resilient attachment
 Restricted vertical resilient attachment
 Hinge resilient attachment
 Combination resilient attachment
 Rotary resilient attachment
 Universal resilient attachment

43.  Stud attachments
 Resilient
 Non resilient
 Ball attachments
 O- ring, ERA system & Spheroflex
 Bars
 Dolder & Hader
 Locator attachment system
 Zaag attachment system
 OT equator
 Hybrid bar system

44. O - RING ATTACHMENT SYSTEM
 Elastomeric retentive attachments
 Doughnut shaped
 Consisting of a ball and a socket

45. Metal Encapsulator

46.  The O-ring post usually is made of machined titanium alloy.
 The post has a head, neck, and body.
 The head is wider than the neck and the O-ring is compressed
over the head during insertion.
 Typically three sizes of O-rings are used in implant prostheses.

47. ADVANTAGES
 Simplicity in design
 Good retention
 Ease of use and maintenance
 Low cost
 Varying degrees of retention
 Possible elimination of a
superstructure.

48. ERA SYSTEM
 Resilient precision OD attachment.
 Universal hinge with vertical movement
 4 color codes
 Types (based on interocclusal distance)
 Standard
 Micro

49. LOCATOR ATTACHMENT
 Zest anchors, escondido, CA, USA) in 2001.
 Classified as universal hinge.
 Dual retention

50. O T EQUATOR
 Rhein83 . The newest line of low profile castable and
direct implant overdenture attachments.
 Low vertical profile - 2.1 mm and diameter of 4.4 mm
 Can be used when vertical space limitations are a consideration.

51. BAR AND CLIP TYPE
ATTACHMENTS
 Bar joint (resilient)
 Single sleeve
 Multiple sleeves
 Bar unit (non-resilient).
 Provides good retention and stability.

52. DISDVANTAGES
 Vertical dislodgement
 Fabrication is technique sensitive
 Higher cost
 Maintenance of hygiene is difficult
 Frequent loosening of retentive clips.

53. HADER BAR AND CLIP
 Helmut Hader (1960s)
 Hader EDS system. Donnel, and Staubli in 1992
 Three different retention strengths and a 20-degree clip rotation to
improve flexibility.

54. DOLDER BAR
 They are classified as combination resilient attachments
 Due to its adjustability, it is easy to control the retention provided
by the bar.

55. MAGNETIC ATTACHMENTS
 Made up of mainly aluminum-nickel-cobalt metals.
 Classified as universally resilient attachments
ADVANTAGES
 Shorter so can be used in cases of reduced inter-
arch space.

56. DISADVANTAGES
 Streaking- MRI
 Least retention
 Heating during sterilization leads to decrease in retentive
forces in long-term use.
 Get corroded in saliva on long-term use

57. CONCLUSION
Implant-supported overdenture proves to be a better treatment
alternative to the conventional denture. Hence, this treatment
modality should be practiced whenever indicated. It will preserve
hard and soft tissues of the patient and give psychological relief to
the patient.

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CLASSIFICATION OF IMPLANT ABUTMENTS

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TYPE OF IMPLANT ABUTMENT CONNECTION
• The implant-abutment interface determines joint strength, stability,
and lateral and rotational stability.

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INTERNAL CONNECTION
• In internal connection implants the implant-
abutment connection is recessed into the
body of the implant

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SIX-POINT INTERNAL HEXAGON

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TWELVE-POINT HEXAGON
• It allows for more options for abutment placement over
the fixture.
• Allows placing the abutment on implant for every 30°
angulation
THREE-POINT INTERNAL TRIPOD
• Triangular internal geometry with trichannel design.
• Disadvantage of this design is that it allows for
positioning of the abutment on fixture only at every
120°

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INTERNAL OCTAGON
• Eight-sided internal geometry and allows for positioning of abutment at
every 45°.
• Offers minimal rotational and lateral resistance during the function.
MORSE TAPER
• Tapered projection from implant abutment that fits into a
corresponding tapered recess in the implant.
• Leading to the friction fit and cold welding at the interface.

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ABUTMENT MATERIALS
TITANIUM
• Excellent biocompatibility.
• Used for custom made abutments as well as prefabricated
abutments.
ALUMINA
• Alternative to titanium abutment to meet the high esthetic
demands.
• High incidence of fractures
ZIRCONIA
• Denser and significantly stronger than alumina.
• Material of choice for all anterior restorations.

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METAL ALLOYS
• Cast restorations that are screw-retained ,used when there is a
limited amount of interocclusal space.
• Not indicated when the implants are short and deeply placed to
avoid peri-implant tissue inflammation.
PEEK
• Indicated as temporary abutments.

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METHOD OF FABRICATION OF ABUTMENT
PREFABRICATED/ STOCK ABUTMENTS
CUSTOM ABUTMENTS

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PREFABRICATED (STOCK) ABUTMENTS
STANDARD ABUTMENT
• Use is usually limited to multiunit restoration, especially in non-esthetic zones.
• Margin of the abutment remains supragingival.
• It allows easy maintenance and
• Margins can be easily inspected.

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CONICAL ABUTMENT
• Commercially known as EsthetiCone.
• Used in esthetic areas for multiple as well as single unit restorations.
• Allows for a good emergence profile.
• Disadvantage: Collar height is uniform circumferentially and it can result in collapse of the
interproximal gingiva.

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ANGULATED ABUTMENT
• Allows for correction of angulation and positional discrepancy.
• Available in 15 to 35° angulations.
• The implant surface of the angulated abutment is 12-sided internally; this shape allows it
to fit onto the hexed implant in 12 different ways to simplify the abutment positioning.

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CEMENTABLE CORE
• Commercially, it is known as CeraOne system.
• The prosthesis which is cemented onto the abutment is fabricated on a core made of either a
gold alloy or a ceramic material.
• Indicated, especially for single tooth replacements.

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POST ABUTMENT
• It is screwed onto an implant intraorally or on implant analog in a master cast and prepared
similarly like a tooth in fixed prosthodontics.

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BALL ABUTMENT
• It is a prefabricated abutment used for the retention of a
tissue-supported overdenture.
• It is available in multiple heights for varying tissue collar.
• Ball abutments can be used with either O-ring attachments or
nylon inserts.

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LOCATOR ABUTMENT

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CUSTOM-MADE ABUTMENTS
CYLINDRIC ABUTMENT
• Commercially known as UCLA.
• The implant surface for this type of abutment is available as
either hexed or non-hexed.

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CUSTOM ABUTMENT
• Allow for an individual emergence profile of the reconstruction directly by the abutment.
• Fabricated by either copy-milling techniques or CAD/CAM systems

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ABUTMENT SELECTION CRITERIA
IMPLANT POSITION
ANGULATION OF IMPLANT
INTER OCCLUSAL SPACE
TISSUE HEIGHT/ SULCULAR DEPTH

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IMPLANT POSITION
• Evaluated as the implant relates to the final prosthesis and the adjacent teeth.
• If the implant lies outside the mesiodistal and buccolingual boundaries of the planned restoration,
then the implant may not be restorable.

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ANGULATION OF IMPLANT
• An angulation discrepancy greater than 15 degrees usually requires an
• angulated,
• cementable, or
• custom abutment.

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INTER OCCLUSAL SPACE
• Corresponds to the vertical distance between the superior surface of the implant and the
opposing dentition in maximum intercuspation.
• Minimum of 2.8 mm of interocclusal space is necessary to restore an implant.

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TISSUE HEIGHT/ SULCULAR DEPTH
• Distance from the superior surface of the implant to the gingival
margin.
• This is measured 6 to 8 weeks following stage 2 surgery.
• Ideally, in esthetically important areas the margin of the restoration
is 1 to 2 mm subgingival.
• The tissue height is not as critical if the restoration is not in the
esthetic zone and a supragingival margin is planned.

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• The process of selecting an abutment involves evaluating the position, angulation, interocclusal
space, and tissue height of a given implant.
• The order of evaluation is extremely important in this method of selection.
• The position is the first consideration.
• The angulation must be evaluated next.
< 15 degree : any abutment other than angulated abutment
15- 35 degree : angulated or custom abutment
>35 degree: custom abutment/ non restorable

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• Interocclusal space
<2.8 mm : non restorable
2.8 mm : cylindric abutment
3.5 mm : cylindric/ post abutment
4.5 mm : all abutments except standard, angulated& cementable core
5.0 mm : all except angulated and cementable core
6.0 mm : all except angulated
>7.0 mm : all abutments

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Tissue height
<1mm : cylindrical,post, custom made
1- 2mm : all except standard / angulated
2-3mm : all abutments
3-5mm : all except cylindrical
>5mm : all except cylindrical / post

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CONCLUSION
• To meet the demand for improved abutments, the implant industry developed an
overwhelming number of components. As a result, selecting an abutment has
become overly complex and confusing.
• The decision on the choice of abutment is based on many factors of which the
clinical situation and clinician’s personal preference leads the selection procedure.

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