3. Bone is a dynamic structure. Excessive loads lead to a
resorptive remodeling response

6. LOAD BEARING CAPACITY ANTICIPATED LOAD
1. Quality of bone site (Affected by)
2. Quality of bone ! Occlusal factors
Cusp angles
implant interface
Width of occlusal table
3. Implant microsurfaces Guidance type
! Machined vs Anterior guidance
microrough vs Group function
nano-enhanced ! Cantilever forces
surfaces
4. Implant Connection to natural
! Number and dentition
Arrangement Size of occlusal table
Linear vs Curvilinear Cantilevered prostheses
! Length and diameter ! Parafunctional habits
! Angulation (bruxism)
! Brachycephalics

8. Linear vs Curvilinear
Curvilinear arrangements have the
greatest load bearing capacity.

10. Courtesy Dr. R. Faulkner

11. Courtesy Dr. R. Faulkner

12. Courtesy Dr. R. Faulkner

13. Courtesy Dr. R. Faulkner

14. In the edentulous mandible,
curvilinear arrangements such as
this one have the greatest load
bearing capacity. The cantilever
length can be double the A-P
spread but not exceeding 20 mm.

16. In this patient a fixed edentulous bridge similar to the one
shown previously, was fabricated for this patient. However,
the cantilever extensions were in excess of 30 mm. Note the
bone loss around the distal implants particularly on the
patient’s left. Eventually this implant fractured.

17. Courtesy Dr. C. Stanford
The size and shape of the
trabeculae is different in the
mandible as compared to the
mandible and may be one of
the reasons why the load
carrying capacity of implant
supported prostheses restoring
posterior quadrants in the
mandible appears to be
superior to those in the maxilla.

18. ! One implant for
each dental unit.
! t least three
A
where possible in
extension areas.

19. ! One implant for
each dental unit.
! t least three
A
where possible in
extension areas.

30. Is it biomechanically more favorable?

31. Is it feasible in the posterior quadrants?

32. Can we use shorter implants?

36. Caputo et al,2002

37. 2 years
5 years
Cho,In Ho et
al, 1992

40. Cho,In Ho et al, 1992

41. Nonaxial loads and implant overload in posterior
quadrants

45. Case Report

46. Cantilever
Cantilever
Overlay Dentures in Edentulous Maxilla

47. Cantilever Cantilever
Overlay Dentures in Edentulous Maxilla
Four implanted supported overlay dentures with nonresilient
(Hader) attachments (arrows) and distal cantilevers
Patients # Implants Followup Failures Position Time of
of failed failure
implants
10 40 5-12 yrs. 4 all distal 39-73 mths.
***Failures were attributed to implant overload, with its
resultant loss of bone around the implants

49. Mesial and distal cantilevers

52. The occlusal tables
are excessively wide
in this case. Buccal
and lingual cantilever
forces may lead in
selected patients to:
! Prosthesis failures
! orcelain fractures
P
! crew fractures
S
! Implant overload and
bone loss

57. Mesial cantilever

61. In this patient, two 4 mm diameter implant were used to
restore the first molar. The width of the occlusal table was
limited to the width of the
natural premolar,
thereby elimating any
possible buccal or
lingual cantilevers.