inroduction ..to fixed prosthodontics.pdf

1. Overdenture
• a complete or partial removable denture supported
by retained roots or implants that is intended to
provide improved support, stability, and tactile and
proprioceptive sensation and to reduce ridge
resorption.
(Mosby. Mosby's Dental Dictionary. Elsevier, 2004.).

3. Synonyms
• Overlay denture
• Onlay denture
• Hybrid denture
• Telescopic denture

4. Classification of
overdenture
OVERDENTURE
TOOTH
SUPPORTED
WITHOUT
ATTACHMENT
DIRECT OVER
TEETH
REDUCTION OF
CROWN
WITH/WITHOUT
ENDODONTIC
TREATMENT
WITH
ATTACHMENT
IMPLANT
SUPPORTED

5. Overdentures:
Why bother?

6. • Complete denture wearers suffered irreversible
bone loss especially in the first year.
• The rate in the mandible being four times than the
maxilla.
• In complete denture wearers, the average alveolar
ridge reduction in 25 years
• lower anterior : 9 – 10 mm
• Upper anterior : 2.5 - 3.0 mm
(Atwood and Tallgren 1972)

7. Classification
of the
edentulous jaw

8. Cawood and Howell
classification
(Int. J. of Oral Maxillofac. Surg. 1988: 17:232-236)

9. Overdenture
s:
Advantages

10. Advantages
1. Preservation of ridge form and alveolar bone.
Radiographic study to compare bone loss
showed that patients with complete
overdentures at canine had less bone
resorption compared patients with
complete dentures only.
Gerodontology 25 (2008) 118-123

11. Mandibular overdenture preserve alveolar bone
in the mandible by 8 times compared to
conventional dentures.
(Crum RJ, Rooney GE 1978)

12. Advantages
2. Retention and stability of denture
• Reduce bone resorption
• Overdenture attachment: magnetic, gold
coping, telescopic crown

13. Advantages
3. Improves occlusal stress distribution
Stress will be shared by the abutments and
edentulous ridge.
(Thayer & Caputo 1979)
4. Increased occlusal forces
• Improves masticatory performances and
chewing efficiency

14. Dentures vs overdentures
• Chewing efficiency
• Natural dentition 90%
• Complete dentures 59%
• Overdentures 79%
(Rissin and House, JPD, 1978)

15. Denture vs implant
overdenture
• Bite forces in mandibular implant retained
overdentures is higher than conventional
dentures.
(Fontjin-Tekamp et al 1998)
• Masticatory performance and chewing experience
in implant retained OD higher than conventional
dentures.
(Geertman et al 1999)

16. Dentures vs
overdentures
• Bite force & chewing efficiency:
• Natural tooth > Tooth supported overdenture >
implant supported overdenture > conventional
complete denture
(Fontjin-Tekamp et al 2000)

17. Advantages
5. Prevent Combination Syndrome

18. Combination syndrome
Complete maxillary denture opposing partially
edentulous mandible with only anterior teeth remaining.
1. Loss of bone at anterior maxillary ridge
2. Enlarged maxillary tuberosities
3. Papillary hyperplasia at hard palate
4. Extrusion of lower anterior teeth
5. Loss of bone under the partial denture bases
(Kelly E., 1972)

19. Combination syndrome

20. Overlay denture on the lower will utilize
the lower tooth roots for stabilization &
provide a complete denture occlusion.
(Kelly 1972)
Preservation of anterior maxillary teeth will
protect the ridge from resorption and
prevent Combination Syndrome.
(Langer & Langer 1992)

21. Advantages
6. Improves crown:root ratio
• Tooth mobility greatly reduced
1 : 1.5 1.5 : 1
1 : 9

22. Advantages
7. Proprioceptive feedback from the periodontal
ligament
• Sensory input from PDL aids in recognition
of jaw position and food texture

23. Advantages
8. Psychological advantages for patients
• Positive perception regarding a retained natural
feeling.
“I still have some of my own teeth to hold my
denture”

24. Advantages: Conclusion
Maintain teeth as part of the residual
ridge
1. Increase support
2. Able to withstand more occlusal
load
3. Improve retention
4. Psychological
Reduce the rate of bone resorption Alveolar bone to support the teeth
Retaining propriception Increase patients’ manipulative skills
to handle dentures

25. Overdenture
s:
Disadvantag
es

26. Disadvantages
• Aesthetic considerations: bulkiness
• Increase interocclusal space requirements
• Increase costs

27. Disadvantages
• Limitation of space due to wear or
compensatory growth
• Potential for fracture of denture base
materials
• Risk of further disease of abutment: caries,
periodontal disease

28. Overdenture
s:
Indications

29. Indications for
overdenture
1. Few remaining teeth
2. Potentially difficult (lower) complete
dentures
3. Avoid edentulous arch opposing natural
teeth to prevent combination syndrome

30. 4. Cleft patients

31. Indications for
overdenture
5. Major tooth wear

32. 6. Interim overlay denture (Diagnostic Purposes)
(Patel MB, Bencharit S, 2009)

33. Tooth-
supported
overdenture

34. Selection of abutment
teeth
1. Periodontal and mobility status
❑ Healthy periodontal tissues
❑ Rendered healthy by periodontal treatment
❑ Circumferential band of attached gingival
around abutment
❑ Mobility of not more than Grade II

35. Selection of abutment
teeth
2. Abutment location
❑ The best: canines and premolars
❑ Upper anterior incisors, if mandibular teeth
still present.
❑ At least one tooth per quadrant
❑ The abutments must not be adjacent (if more
than one abutment)

36. Consideration in selection of maxillary teeth as overdenture
abutments
Maxillary
teeth
Advantages Disadvantages
Central
incisors
• Ideal location
• Provide protection to the premaxilla
• Proximity and alveolar prominence may
complicate utilization
Lateral incisors • Widely separated, facilitating plaque
control
• No tissue undercuts
• Path of placement/removal is not
compromised
• Ability to create a flange/peripheral
seal
• Diminished root surface area
Canines Longest root of the anterior teeth • Diverging facial undercuts
• Overcontoured flanges
• Excessive lip support
• Potentially uncomfortable
placement/removal of prosthesis
• Complicates placement of prosthetic
teeth
• Internal relief to accommodate canines
may weaken, create food trap,
compromised peripeheral seal
Nelson & von Gonten, J Prosthet Dent 1994

37. Selection of abutment
teeth
3. Endodontic and Prosthodontic status
❑Anterior single rooted teeth are easier and less
expensive.
❑If pulpal recession to the extend of calcification
occurred, endodontic treatment can be
avoided.

38. Overdentures: the
principles
• Maximum reduction of the coronal portion of the
tooth
• Better crown:root ratio
• Space for artificial teeth

39. Overdentures: the
principles
• To RCT or not?
• RCT increases the coronal reduction that can be
achieved.
• Elderly patient: sclerosed canals
• Severe toothwear: to RCT or not?
11% (52 out of 448) of tooth wear cases need RCT
(Sivasithamparam et al 2003)

40. Overdentures: the
principles
• Abutments without attachment:
• Devitalized tooth can be restored with
amalgam, composite resin or GIC.
• Less expensive
• For stability and retardation of RRR

41. Overdentures: the
principles
• Abutments with attachment mechanism on
cast coping:
• intracoronal/extracoronal attachments.
• Provide prosthesis retention.
• Disadvantages:
• Interarch space
• Increase costs
• Technique sensitive
• Demanding oral hygiene maintenance

42. Tooth-supported
overdentures:
Clinical procedures

43. Clinical procedures
• Tooth supported immediate complete
dentures
• Prepare the dentures and complete endodontic
treatment.
• Reduction of coronal portion of abutment teeth
prior to insertion of dentures

45. Leinfelder et al, 2008
Reline overdenture

46. Onlay denture

47. Clinical procedures
• Tooth supported overdenture with attachment
• Prepare the dentures and complete endodontic
treatment.
• Reduction of coronal portion of abutment
teeth.
• Cementation of attachment to the abutment
teeth
• Impression followed by construction of
dentures.

49. Complicati
ons

50. Loss of abutment teeth
• The most frequent causes of abutment loss:
• Caries
• Periodontal disease
• Endodontic complications
• Poor clinical follow-up and patient compliance.

51. Gingival irritation of
abutment teeth
• The causes:
• Movement of denture base (esp mandibular
denture)
• Poor oral hygiene
• “dead space”: source of inflammation and
tissue hypertrophy and hyperplastic response.

52. Loss of overdenture abutments was only 4.2%.
Mostly due to caries and periodontal diseases.
(Ettinger 1988)
Possible to maintain teeth as overdenture
abutments with good oral hygiene.
(Budtz- Jorgensen 1995)

53. 81% of three-teeth telescopic overdentures were
maintained at 8 years.
But…
Loss of dentures were more of a problem than
loss of abutments!
(Griess, Reilmann and Chanavaz 1998)

54. • Tooth and tissue supported overdenture vs
tooth supported overdenture
• Abutment failure rate are the same.
• Abutment present: 84% at 5 years and 66% at 10
years.
(Wenz et al 2001)

55. Maintenanc
e

56. Overdentures:
maintenance
• Abutments are examined every 6-monthly
• Patient is instructed to brush over
abutments twice daily.
• Dentures must be kept clean.
• Chlorhexidine mouthwash
• Topical fluoride 1x/day using denture as
applicator.

57. Implant retained
overdenture

58. Implant retained
overdenture
• Dentures which utilize dental implants for
retention and support.
• Superior retention and stability
• Reduce the amount of soft tissue coverage

59. Implant retained
overdenture

60. Patients with implant supported
overdenture has significantly higher
quality of life than patients with
conventional dentures.
Mc Gill Consensus Statement 2002
Implant supported overdenture is the
standard of care to edentulous patients.

61. York Consensus Statement (2009)
Mandibular 2 implant-supported
overdenture is the first choice
standard of care for edentulous
patients.

62. Less bone resorption
70% implant supported overdenture patients has
bone resorption of less than 0.2mm during the
first year and 0.6 mm in 5 years.
(Schwartz-Arad et al)

63. Greater prosthesis
stability
• Implant retained overdenture is more stable.
• Conventional mandibular denture moves
during function:
• Soft tissue abrasion
• Accelerate bone loss
• Clicking noise during speech

64. Indications for implant
overdentures
• Patients who lose their teeth in advanced age.
• Poor control of the dentures:
• Patient who had complete dentures for many years,
but lose their motor skills and no longer feel able to
wear complete dentures.
• This problem is observed much more often for the
edentulous mandible than maxilla.

65. Implant supported
overdenture
• Kenneddy Class I and II removable partial
denture

66. Implant retained
overdenture
• Complete denture:
• 4 or 6 dental implants for upper overdenture

67. • Complete denture:
• 2 or 4 dental implants for lower denture.

68. Implant vs conventional
denture
• Allow removal of the palatal
coverage.
• More comfortable and improves
taste sensation
• Full palatal coverage for
retention and support

69. Types of
retention/anchorage
devices
• Dolder bar

70. Types of attachments
• Locator/attachment
• Magnets
• Ball attachment

71. • Mini implants

72. Simplicity

73. Recall/maintenance visit
• Four phases:
1. Examination, re-evaluation, diagnosis;
2. Motivation, reinstruction, instrumentation;
3. Treatment of infected sites;
4. Polishing, fluoridation, determining recall
interval.
(Lang NP et al 2000)

74. Recall/maintenance visit
• Assessment and adjustment of:
• the fit of denture bases
• occlusion
• Attachment mechanisms

75. • Five parameters:
• Bleeding on probing
• Bleeding index
• Gingival index
• Mobility
• Radiographic bone level (every 12 to 24 months)

76. Thank you
wan_syariza@usim.edu.my