failure

1. Failures in Implants
1

2. •Introduction
•Definitions
•Predictors of implant success or failure
•Warning signs of implant failure
•Criteria for implant success:
•Implant quality scale:
•Classifications of implant failures
.Enhancing outcome in esthetic implant dentistry
.implant maintenance
•Conclusion
•Bibliography
Contents…
2

3. Implant dentistry is currently
being practiced in an atmosphere
of enthusiasm and optimism,
because our knowledge and ability
to provide service to our patients
has expanded so greatly in such
a short period.
But Success cannot be guaranteed, what one
can guarantee is to care, to do ones best and to be
there to help in the rare instance that something goes
wrong
Introduction
3

4. 4

5. 5

6. The surgeon’s tale
‘The implants were successfully integrated , but
failed because of excess loads.
or
The Restorative Dentist’s tale
‘The implants were poorly integrated and so failed
under normal masticatory loads.’
either way
The Patient’s tale
‘My implants have failed!’
………When implant fails……then……….
6

7. 7

8. IMPLANT FAILURE…
It is defined as total failure of the implant to
fulfill its purpose (functional, esthetic or
phonetic) because of mechanical or biological
reasons.
(Askary et al ID 1999 vol8 no2 173-183)
Definitions …
8

9. Ailing implants:
Those that show radiographic bone loss without
inflammatory signs or mobility.
Failing Implant:
Characterized by progressive bone loss, signs of
inflammation and no mobility.
9

10. Failed Implants:
Those with progressive bone loss, with clinical
mobility and that which are not functioning in
the intended sense.
Surviving implants:
Described by Alberktson, that applies to
implants that are still in function but have
been tested against the success criteria.
10

11. Predictors of implant success or failure
( General dentistry 2005, 423-432)
Positive factors
 Bone type (type 1and 2)
 Patient less than 60yrs old
 Experienced Clinician
 Mandibular placement
 Implant length > 8mm
 FPD with more than two implants
 Axial loading of implant
 Regular postoperative recalls
 Good oral hygiene
11

12. Negative factors
Bone type (type 3 and 4)
Low bone volume
Patient more than 60yrs old
Limited clinician experience
Systemic diseases
Auto-immune disease
Chronic periodontitis
Smoking and tobacco useUnresolved caries,
endodontic lesions,frank pathology
Maxillary, particularly posterior region
Short implants (<7mm)
Eccentric loading
Inappropriate early clinical loading
Bruxism and other parafunctional habits
12

13. Warning signs of implant failure
(Askary et al ID 1999; vol 8; no2, 173-183)
Connecting screw loosening
Connecting screw fracture
Gingival bleeding and enlargement
Purulent exudates from large pockets
Pain
Fracture of prosthetic components
Angular bone loss noted radiographically
Long-standing infection and soft tissue
sloughing during the healing period of first
stage surgery
13

14. Criteria for implant success:
…The individual implant is immobile when tested clinically.
…No radiographic evidence of peri-implant radiolucency
…Bone loss no greater than 0.2 mm annually
…Gingival inflammation amenable to treatment
…Absence of symptoms of infection and pain
…Absence of damage to adjacent teeth
…Absence of parasthesia, anesthesia or violation of the
mandibular canal or maxillary sinus
…Should provide functional survival for 5 years in 90% of
the cases and for 10 years in 85%.
(Albrekfsson T. :int J. Oral Maxillofac Implants 1986; 1:11-25)
14

15. Implant qualityscale:
The scale presented for implant quality of health based on clinical
evaluation was first suggested by James and was modified by Misch.
This quality of health scale criteria, has to be place in the appropriate
category, and then treat the implant accordingly.
The prognosis also is related to the quality scale.
15

16. 16

17. ClassificationOf Implant failures
…E.S Rosenberg, J.P. Torosian and J. Slots
…Abdel Salam El Askary, Roland Mefert and Terrence Griffin
…Kees Heydenrijik, Henny JA Meijer, Wil A Van der et al
… Marco Esposito, Jan Michael Hirsh, Ulf Lekholm et al
…Sumiya Hobo, Eiji Ichida, Lily T Garcia
17

18. 1. Infectious Failure:
…Clinical signs of infection
with classic symptoms of
inflammation
…High plaque and gingival
indices
…Pocketing
…Bleeding, Suppuration
…Attachment loss
…Radiographic peri-implant
radiolucency
…Presence of
granulomatous tissue upon
removal
2. Traumatic Failure:
…Radiographic periimplant
radiolucency
…Mobility
…Lack of granulomatous
tissue upon removal
…Lack of increased
probing depths
…Low plaque and gingival
indices
A) E.S Rosenberg, J.P. Torosian and J. Slots
classified as :
18

19. B) Marco Esposito, Jan Michael Hirsh, Ulf Lekholm et al
have classified oral implant failures according to the
osseoi ntegration concept.
1)Biological Failures:
•Early or primary (Before loading)
•Late or secondary (After loading)
2)Mechanical failures:
•Fracture of implants, connecting screws,
bridge framework, coatings etc
3)Iatrogenic Failures
• Improper implant angulation and alignment, nerve
damage
4)Inadequate Patient adaptation
• Phonetics, esthetics, psychological problems.
19

20. C) Kees Heydenrijik, Henny JA Meijer, Wil A Van der et
al classified to occurrence in time as:
1) Early Failures: Causes attributed are:
• Surgical trauma
• Insufficient quantity or quality of bone
• Premature loading of implant
• Bacterial infection
2) Late Failures:
Soon late failures: Implants failing during first year of
loading. Overloading in relation to poor bone quality and
insufficient bone volume.
Delayed late failures: Implant failing in subsequent years.
Progressive changes of the loading conditions in relation
to bone quality, volume and peri -implantitis.
20

21. Swedish Team
( Branemark et al)
U.C.L.A team
(Beumer, Moy)
1. Loss of bone anchorage:
a. Mucoperiosteal
perforation
b. Surgical trauma
2. Gingival problems:
a. Proliferative gingivitis
b. Fistula formation
3. Mechanical complications:
a. Fracture of
prosthesis, gold screws,
abutment screws
1. Complications in Stage I surgery;
2. Complications in Stage II surgery:
3. Prosthetic complications:
D) Sumiya Hobo, Eiji Ichida, Lily T Garcia enlisted
various complications occurring in implants as:
21

22. E) Abdel Salam el Askary, Roland Meffert and
terrence griffin …
According to etiology
Restorative
factor
Host
factor
Surgical
factor
Implant
selection factor
According to timing of failure
Before stage II After stage II After restoration
According to origin of infection
Peri- implantitis
(Infective process,
bacterial origin)
Retrograde peri-implantitis
(Traumatic occlusion origin,
non infective, forces off the long
axis, premature or excessive
loading) 22

23. According to failure mode
Psychological
problems
Lack of
osseointegration
Unacceptable
aesthetics
Functional
problems
According to condition of failure
Ailing Implant Failing Implant Failed Implant Surviving Im.
According to supporting tissue type
Soft tissue loss Bone loss Combination
According to responsible personnel
Dentist (Oral
surgeon,
Prosthodontist,
Periodontist)
Dental
hygienist
Laboratory
Technician
Patient
23

24. According to etiology
Restorative
factor
Surgical
factor
Implant
selection factor
Host factor
Medical status : Habits : Oral status
24

25. A. Hostfactors…
MEDICAL STATUS… medical history is essential to rule out any of
the following conditions or disorders. If yes… medical consultation
Bone dieases
CV Dieases
Autoimmune
Endocrine
Pregnancy
Hypertension
MI
Congestive heart
failure
SABE
 DM
 Thyroid
disorders
 osteoporosis
 osteomalacia
? hyperparathyriodism
fibrous dysplasia
paget dz
multiple myeloma
? osteomylitis
 sjogren syndrome
? SLE
? scleroderma
? HIV
25
Avoid to place
implant in pregnancy
…In all these conditions ,chances of
success rate are poor but implant
therapy … not contraindicated except
few.
Etiology : host factor

26. HABITS
1) Smoking:
Significance
•Causes alveolar vasoconstriction and decreased blood flow
•Impaired wound healing due to compromised polymorphonuclear
leucocytes function, increased platelet adhesiveness as well as
vasoconstriction caused by nicotine.
•Poor bone quality
•In case of poor oral hygiene, smokers have 3 times more marginal bone
loss then non-smokers
Recommendations:
1.Obtain a smoking history
2.Advice on risks of periodontal breakdown
3.Advice on the prognosis .Smoking cessation
Etiology : host factor
26

27. Parafunctional habits:
Bruxism is the multidirectional nonfunctional grinding of
teeth. Clenching occurs in one direction (vertically).
Bruxism is more aggressive. Attrition usually appears on
the incisal edges of anterior teeth.
Significance
•Most common cause of implant bone loss or lack of rigid fixation
during the first year after implant insertion.
•Commonly manifests as connecting screw loosening because of overload.
•Failures are higher in maxilla because of decrease in bone density.
•Forces are in excess of normal physiologic masticatory load limit.( upto
1000 psi).
Etiology : host factor
27

28. Prevention
•Increased number of implants to be placed
•Avoid cantilevers and occlusal contacts in lateral excursions
•Use of occlusal splint which is relieved over the implant.
•Use of wide diameter implant to provide greater surface area.
Progressive bone loading and prosthetic design that improves the
distribution of stresses throughout the implant system.( By Misch
Etiology : host factor
28

29. Poor home care:
ORAL STATUS:
Suprabony connective tissue fibers are
oriented parallel to the implant surface
Susceptible to plaque accumulation and
bacterial ingress
Spontaneous loss of the perimucosal seal
Chances of implant failure increases
Etiology : host factor
29

30. Prevention
•It is recommended that the patient be recalled
frequently, preferably at a minimum of 3 months
intervals. Periodontal indices, bleeding on probing and
radiographic evaluation should be performed, using plastic
tipped probes for checking pocket depths.
•Soft tissue debridement should be performed by means
of plastic curettes and plastic tips for ultrasonic scalers,
and topical and systematic antimicrobial drugs should be
used
•Provide space beneath the superstructure to allow
cleansing aids
Etiology : host factor
30

31. IRRADIATION THERAPY
Significance
•Xerostomia
•Susceptibility to infection
•Osteoradionecrosis
•Endarteritis of vessels causes decrease in oxygen supply
Prevention
•Waiting period of 9-12 month between radiation therapy and implant
treatment.
•Hyperbaric oxygen therapy – 20 treatments of 90 min. each at 2 to
2.4atm before surgery.
•Antibiotic regimen 3 days before (augmentin 500mg every 12 hrs).
Etiology : host factor
31

32. According to etiology
Restorative
factor
Host
factor
Implant
selection factor
32

33. a) Off-axis placement (severe angulation)…
Occlusal load lie at an angle
Shear & tensile forces increases
Chances of failure increases
Problem…
Due to…
A) Alveolar process resorption
B) Unexperienced surgeon
C) Improper surgical stent
Etiology : surgical factor
33

34. 1) Prerestoring the implant position by
grafting
2) To place the implant with an angulation.
3) To place angulated abutments.
Solutions…
Etiology : surgical factor
34

35. b) Lack of initial stability…
Due to oversized osteotomy
Gap develop between implant & bone
Lack of osseointegration
In an experimental investigation, gaps in the range of
0.25 mm around CPTi implants healed, but with less bone
contact than the controls.
When the gap size increased to 0.7mm-1.7mm,
a thin soft tissue layer was found to develop
around the implant.
Etiology : surgical factor
35

36. Solution…
Remove & reinsert the larger size implant.
if not possible  remove insert HA graft material
roll the implant moistened in blood & saline & in the
particulate slurry until thin layer of slurry clings to it 
reinsert the implant
Etiology : surgical factor
36

37. c) Improper healing & infection
because of improper flap design…
No single flap design is optimal for implant surgery.
But improper flap design  infection & bacterial ingress 
chances of failure increases
Note: basic surgical procedure, flap design ,
blood supply, visibility,access, primary
closure should be considered.
Etiology : surgical factor
37

38. d) Overheating the bone and exerting
too much pressure……
Etiology : surgical factor
Excessive pressure Bone cell damage Bone loss
Connective tissue
interface formed
Failure increases
…Inverse relationship b/w speed & heat production
…Recommended speed- 2000 rpm with graded series
of drill size with external irrigation 38

39. Etiology : surgical factor
39

40. e) Placement of implant in immature bone
grafted site…
Etiology : surgical factor
Minimum waiting period of grafted site…6-9 mth
woven bone present before this period, which is fastest
formed bone (partly mineralized &Unorganized)
Lamellar bone ideal for
implant prosthetic support
Not suitable for implant-bone integration
40

41. f) Contamination of implant body before
insertion…
D/t 
…non-titanium instrument
…by glove powder
…by the operatory error
By autoclaving the contaminated implant
Bake the bacteria on implant surface
Impossible for phagocytic cell to clean the surface
No close adaptation to the bone
Etiology : surgical factor
41

42. Etiology : surgical factor
42

43. According to etiology
Restorative
factor
Host
factor
Surgical
placement
Implant selection factor…
…Improper implant type in improper bone type…
…length of the implant…
…width of the implant…
…number of the implant…
…improper implant design…
43

44. Length of the implant..
Misch proposed the range of 10mm-16mm length.
The greater the crown implant ratio, the greater the
amount of the force with any lateral force. This means
that the implant with unfavorable crown implant ratio will
be more influenced by lateral forces. Therefore,
maximum implant length must be used for the greatest
stability of the overlying prosthesis.
The success rate is proportional to the implant length and
the quantity and quality of available bone. The rate of
failure can be expected to rise proportionately as the
depth of the bone diminishes to less than 10mm.
44

45. Width of the implant…
Misch recommended that not less than 1 mm of bone
surrounding the fixture labially and lingually is mandatory
for the long term predictability of dental implants because
it maintains enough bone thickness and blood supply.
…it is advisable to use a large- diameter implant in
accordance with the available bone width because it
offers greater surface area, greater mechanical
engagement of the cortical bone, and initial rigidity.
Using a wide implant in a narrow ridge results in labial
or lingual dehiscence that leaves the implant affected
by the damaging shear stresses.
45

46. Number of implants…
Misch stated that the use of more implants decreases the
number of pontics and the associated mechanics and strains
on the prosthesis, and dissipates stresses more effectively
to the bone structure. It also increases the implant bone
interface and improve the ability of the fixed restoration
to withstand forces.
Contrary to this Smith et al correlated between the
increased number of implants and the high failure rate
caused by wound contamination that might occur because of
the long operating time.
46

47. According to etiology
Host
factor
Surgical
placement
Implant
selection factor
47

48. Excessive cantilevers…
……Used implant-supported
prosthesis.
……Mesial C. > Distal C…….
…Cantilever extensions cause load magnification and
overloading of the implant next to the cantilever
extension, which in turn leads to bone loss
…With occlusal forces acting on the cantilever, the
implant becomes a fulcrum and is subjected to
rotational forces
Etiology : restorative facto
48

49. Not preferred ----moderate to
severe parafunctional habits
Opposing arch…
…ideally a denture
…no lateral forces on cantilever
Amount of force increases if…
…Length of cantilever
…distance between implants
…crown height
…direction of force
…position of arch
Etiology : restorative facto
49

50. Connecting implants to teeth…
Not preferred…
Difference b/w implant & tooth movement
in vertical & lateral direction
Etiology : restorative facto
50

51. Solution…
…… increase no. of implants
…… improve stress distribution by splinting additional
abutment until 0 clinical mobility is observed.
…… non-rigid connection – but chances of
intrusion of the tooth.
Etiology : restorative facto
Criteria…
1) no observable clinical mobility of natural abutment.
2) no lateral force should be designed on prosthesis.
51

52. Pier Abutments…
Etiology : restorative facto
Main complication d/t difference of mobility of tooth & implant
…2 situations arise…
Implant as pier Tooth as pier
…Tooth act as living pontic or
pontic with a root
…stress breaker –not indicated
Act as class 1 lever
Non rigid attachment
52

53. One of the most critical elements affecting the long-
term success of a multiple implant restoration is the
passive fit between the framework and the underlying
fixtures.
A passive fit reduces long term stresses in the
superstructure, implant components, and bone adjacent
to the implants.
A poorly fitting implant framework can cause
mechanical complications such as loose screws or
fractured components.
No passive fit…
Etiology : restorative facto
53

54. Improper fit of abutment…
Improper locking b/w abutment-fixture interface
Increased microbial population &
increased strain on implant component
Bone loss
Rapid screw-joint failure
Etiology : restorative facto
54

55. Important guidelines to follow
• Infraocclusion upto 30 microns of implant supported
restoration
• No balancing contacts on cantilevers.
• No guidance on single implants.
• Freedom in centric.
• Occlusal table directly proportional to implant diameter.
• Narrow occlusal width.
• Implant length: crown-root ratio ideal – 1:2 ,
Acceptable – 1:1 for removable denture.
• Avoidance of cantilever length.
Maximum 10 to 15 mm is advised. 7 mm is optimum .
• Shallow central fossae with tripodal cuspal contacts.
• No contact in lateral excursion.
• Slight contact in centric occlusion.
Etiology : restorative facto
Improper occlusal scheme…
55

56. According to timing of failure
Before stage II
After stage II
After restoration
56

57. Problem Possible cause Solutions
Hemorrhage during
drilling
Lesion or injury of
an artery
-The implant placement will
stop the bleeding.
-Simple tamponade , bone
wax, gelfoam , surgicel ,
avitene can also be used
Implant mobility
after placement
Soft bone
Imprecise
preparation
Remove the implant and
replace with one of larger
diameter. If the mobility is
small prolong the healing
time
Exposed implant
threads
Too narrow crest Cover the threads with
coagulum or place a
membrane
Swelling lingually
directly after implant
placement at the
mandibular symphysis
Incision of an
artery branch
sublingually
EMERGENCY: send the
patient to a specialist
center for coagulation of
the artery under general
anesthesia
First stage surgery
57

58. Injury to neurovascular bundle…
The posterior mandible in particular presents
significant challenge when severe atrophy
leaves little, if any bone superior to inferior
alveolar canal.
…The solution to limited space for posterior mandible fixture
placement includes detailed initial treatment planning and careful
surgery to unroof the canal and move the neurovascular bundle
inferiorly prior to fixture installation… 58

59. Problem Possible causes Solutions
Slightly sensitive but
perfectly immobile
implant
Imperfect
osseointegration
Cover the implant for 2-3
months and test again
Slightly painful and
mobile implant
Lack of integration Remove the implant
Difficulty inserting a
transfer screw, gold
screw or healing cap
Damaged inner
thread of abutment
screw
Change the abutment
screw
Inability to perfectly
connect the abutment
to the implant
Insufficient bone
milling
Place a local anesthesia,
use a bone mill with guide,
remove the bone, clean
with saline solution, and
replace the abutment
Granulation tissue
around the implant
head
Traumatic placement
of the implant;
compression from the
transition prosthesis;
a lid above the cover
screw
Open the area and
disinfect with
chlorhexidine. If the
lesion is too large,
consider a bone
regeneration or grafting
technique
Secondstagesurgery+ abutmentconnection
59

60. Problem Possiblecauses Solutions
Pain or sensation
when tightening
gold screws
(during try in of
prosthesis)
Misfit
between
prosthesis
and
abutments
Cut the prosthesis; interlock the
pieces, and solder the prosthesis at
the laboratory. Retry the
prosthesis
Loosening of one
or more
prosthetic screws
at the first
inspection after
two week
Occlusal
problem
Retighten, verify the occlusion, and
recheck after two weeks.
Prostheticproblems
60

61. Loosening of
prosthetic screws
at the second
check or later
Occlusal problem or
misfit between
prosthesis and
abutments
Too large extension
Unfavourable
prosthetic concept
Verify the occlusion and/ or
the prosthetic fit
Reduce the extension
Change the prosthetic design.
In all cases, change the
prosthetic screws
Fracture of a
prosthetic screw
or an abutment
screw
Occlusal problem, lack
of fit between the
prosthesis and the
abutment or
unfavourable
prosthetic design
If the occlusion or the
adaptation of the prosthesis
seems right, modify the
prosthetic design (reduce or
eliminate extensions, reduce
the width of occlusal surfaces,
reduce cuspal inclination, add
implants, etc)
Prostheticproblems
61

62. Fracture of the
framework
Weak metal
frame end or
too large
extension
Bruxism or
parafunction
Remake the prosthesis; modify the
prosthetic design (reduce or
eliminate extensions, reduce width
and height of occlusal surfaces,
reduce cusp inclination, add implants,
etc).
Make a nightguard
Implant fracture Occlusal
overload
Remove the implant with a special
trephine drill, wait 2- 6 months, if
possible, and place a wider implant.
Review the prosthetic design(place
more implants, etc) and remake the
prosthesis
Prostheticproblems
62

63. 1. Continuing
bone loss around
one or more
implants
Infection
(peri-
implantitis)
Remove the etiolgical factors (poor
plaque control, prosthesis geometry
in relation to the mucosa, etc). Look
for bacterial pockets around the
natural teeth. Possibly make a
bacteria test. Cut open the lesion.
Adjust the peri-implant tissues
(gingival graft). Consider a bone
regeneration procedure
2. Continuing bone
loss around one or
more implants
Occlusal
overload
Modify the prosthetic design (reduce
or eliminate extensions, reduce the
width of occlusal surfaces, reduce
cuspal inclination, add implants, etc)
Prostheticproblems
63

64. Psychological
Problems
According to failure mode
Lack of
Osseointegration
Unacceptable
Aesthetics
Functional
Problems
64

65. Lack of Osseointegration……
Adell et al proposed that lack of osseointegration can be due to……
……Surgical trauma
……Perforation through covering mucoperiosteum during healing
……Repeated overloading with microfractures of the bone at early
stages
Functional problems……
Proper function of the implants is dependent on two main types of
anchorage related and prosthesis related.
Anchorage related factor…
Osseo integration
Marginal bone height
Prosthesis related factor…
Prosthesis design
Occlusal scheme
65

66. Aesthetic problem……
Aesthetic outcome is affected by four factors:
…Implant placement
…Soft tissue management
…Bone grafting consideration
…Prosthetic consideration
Psychological problems……
…high expectations of the patient
66

67. …Soft tissue problems
…Bone loss
…Both soft tissue and bone loss
According to supporting tissue type……
67

68. Soft tissue problems
Gingival loss leads to continuous recession around the implant with
subsequent bone loss. This will lead to a soft tissue type of
failure.
Significance of attached gingiva surrounding implants
…facilitates impression making.
…provide tigth collar around the implant.
…prevent recession of marginal gingiva.
…prevent spread of inflammation to deep tissue.
68

69. Ono,Nevin,Cappetta classified keratinized gingiva based on
reflection of quantity & location in mucogingival
surgery during implant placement……
Type 1- flap can be apically positioned to
increase the zone of keratinized gingiva on
facial side
Type 2-minimum keratinized tissue on ridge but little on facial aspect
Type 2 class I- gingival graft Type 2 class II- gingival graft on buccal side,
Apically positioned flap on lingual site
69

70. Type 3- no attached gingiva on the ridge or facial aspect.
A gingival graft which is apically postioned to increase the
Zone of attched gingiva.
70

71. Bone loss
Loss of marginal bone occurs both during
the healing period and after abutment connection
Bone loss in mandible is higher during the healing period.
In maxilla, bone loss is higher after abutment connection
Bone functions as a support for the implant and that any
disturbance in its function may lead to eventual loss of the implant.
71

72. Factors that contribute to marginal bone loss:
•Surgical trauma such as detachment of the periosteum and
damage cased during drilling
•Improper stress distribution caused by defective prosthetic
design and occlusal trauma
•Physiological ridge resorption
•Gingivitis, which if allowed to progress will lead to ingression
of bacteria and their toxins to the underlying osseous structures.
Both soft tissue and bone loss
If failure starts from soft tissue, then it usually is
considered to be due to a bacterial factor. However, if
failure starts at the bone level, then it is considered to
be due to a mechanical factor. Both bone and soft
tissue may be involved together.
72

73. Enhancing esthetic outcome
in implant dentistry…
Prosthodontic
considerations
Surgical
consideration
Use of
platelet–rich-plasma
73

74. Prosthodontic consideration…
1) Interim provisional restoration:
Resin bonded FPD
Use of transitional implants to
Support an interim provisional restoration
Modified Essex retainer
74

75. 2) Prosthetic guided soft tissue healing:
Custom abutment & tooth form restoration
Custom tooth form healing abutment
75

76. Surgical consideration…
Cosmetic laser soft tissue resurfacing & sculpting
Creating harmony with cosmetic PD surgery
76

77. Use of platelet-rich-plasma
…Provide blood component & source of growth factor
which enhance the wound healing
…3-4ml of non-activated P-R-P is sufficient
for multiple implant site
Hard tissue
consideration
Soft tissue
consideration
Both
…enhancing osseointegration
…alveolar ridge preservation
…in autogenous bone graft
77

78. Peri- implantitis
Progressive peri-implant bone loss in conjunction
with a soft tissue inflammatory lesion is termed peri-
implantitis.
Pathological changes of the peri-implant tissues can
be placed in the general category of peri-implant
disease. (Lang et al 1994)
Two primary etiological factors
1. Bacterial infection
2. Biomechanical overload
(Newman et al 1988, 1992, Rosenberg et al 1991)
78

79. Classification of peri-implantitis
Class I
…Slight Horizontal bone loss with
minimal Peri-implant defects.
TREATMENT……Initial therapy for removal of
etiological factors.
…Surgical therapy includes cleaning the implant
surface, Pocket elimination via Apicalpositioning
of flap.
Class II
…Moderate horizontal bone loss with isolated
vertical defects.
TREATMENT
…Initial therapy for removal of etiological
factors
…Surgical therapy includes cleaning the implant
surface pocket
…Elimination and adjunctive treatment using
systemic antimicrobials 79

80. Class III
Class IV
Moderate to advanced horizontal
bone loss with broad, circular
bony defects.
TREATMENT
…Initial therapy for removal of etiological
factors
…Surgical therapy includes cleaningthe implant
surface
…pocket elimination via osseous regeneration
and adjunctive antibiotic treatment
Advanced horizontal bone loss with broad
circumferential vertical defects as well as loss
of buccal and lingual bony wall.
TREATMENT
.Initial therapy for removal of etiological factors
.Surgical therapy includes cleaningthe implant
surface,pocket elimination via bone regeneration
techniques, possibly autologous bone transplants
with adjunctive antibiotic therapy.
80

81. These are primarily related to failure of
prosthodontic materials to resist forces and
stresses of oral function.
Mechanical complications…
81

82. Fractured abutment screw
Tip of the explorer is placed on the top
portion of the fractured abutment
screw.
With slight apical pressure and a
counterclockwise circular motion, the
fragment can often be unscrewed.
Care must be taken not to damage
the internal threads of the implant.
……When Screw Fragment removed ,replace with
appropriate new abutment and screw. Verify seating
with a radiograph prior to final torque.
……Replace prosthesis and secure with new retention
screws. 82

83. Radiographic evaluation of a
loose healing abutment.
Removal of healing abutment
indicates a distorted screw
Treatment:Replace with new
healing abutment
Loose Healing Abutment
83

84. Area of
concern
Radiograph confirms poor
seating abutment.
Diagnosis- possible loose or
fractured abutment screw
Clinical evaluation after removal
of bar indicates loose abutment
screw.
Treatment:Retorque abutment
screw.
Loose bar…
84

85. Treatment:
continued
2 - Abutment screw is
tightened with
abutment driver.
3 - Bar is then
replaced and prosthetic
screws are torqued with
appropriate screw
driver.
85

86. Loose restoration…
Radiographic Evaluation: Small
opening at abutment-implant
interface
Small
opening
Diagnosis:Loose abutment
screw
Treatment:
1 - Loosen screw and
remove restoration
86

87. 2 - inspect the implant hex
for damage
3 - inspect the restoration
for damage
Implant hex
Abutment hex
(A) No Damage to fixture or restoration
…replace restoration and secure with the
same screw.Verify seating with
radiograph prior to final torque.Recheck
occlusion with shimstock.
(B) Damaged fixture hex and or restoration
replace restoration and secure with
appropriate new screw. 87

88. Fixture loss
(Must differentiate b/w “failing” and “failed”)
Failing Implant
Clinical signs:progressive bone loss
:soft tissue pockets and crestal bone loss
:bleeding on probing with possible purulence
:tenderness to percussion or torque forces
Causes:overheating of bone at the time of surgery
or lack of initial stability.
:inadequate screw joint closure
:functional overload
:periodontal infection (peri-implantitis)
Treatment:Interim: remove prosthesis and abutments
:irrigate with Peridex
:ultrasonic and disinfect all components
:reinsert assuring proper screw torque
:recheck passive fit of framework and occlusion 88

89. Causes:
:surgical compromise (overheating bone and
initial lack of stability).
:Inadequate screw joint closure
:Too rapid initial loading
:Functional overload
:Periodontal infection (“peri-implantitis”)
Clinical signs:
…Mobility…verify fixture mobility by removing any
abutments and superstructures first.
…A “Dull” percussion sound has been associated
with a failed implant.
…Peri-implant radiolucency can be a radiographic
finding often this is not evident on an X-ray
Failed Implant
Treatment
:removal of the implant 89

90. Treatment:Eventual implant removal
Fractured implant fixture head
90

91. Accidental swallowing or inhalation of components and /or instruments
Many implant components are as small as are
the instruments used for their manipulation. When
coated with saliva a component may escape the
clinicians grip and fall into the oropharynx, reflex
swallowing may take the component out of site
almost immediately.
Prevention
Manual screwdrivers and similar instruments should
always be equipped with a safety line of dental
floss.(Minimum length of 10mm)
91

92. 92

93. …oral hygiene
…implant stability (evaluate mobility)
…peri-implant tissue health
…crevicular probing depths
…bleeding
…radiographic assessment (serial)
crestal bone level (expect 1.0mm marginal
bone loss during first year postinsertion;
0.1mm per year anticipated thereafter )
…proper torque on screw joints
…occlusion
…Patient comfort and function
The following factors must be evaluated at
each maintenance appointment……
93

94. Hygiene aids……
Super - floss
End tufted brushes
Proxy brushes
Tartar control dentrifices
Mechanical instruments
94

95. Super - Floss
Excellent for all types of
implant restorations
Butler Post Care Floss Aid
Excellent for implant
bars and fixed hybrid
prostheses.
95

96. Butler Floss Aid is used
to clean the bar
including the area
contacting the tissue.
96

97. End tufted brushes
Proxy brushes
97

98. Plastic scalers are
appropriate for cleaning
around standard abutments
supporting implant bar
substructures, hybrid
prostheses and implant
supported splinted
restorations.
Plastic scaler tips are
also available for metal
handle scalers.
Plastic scalers…
98

99. Implant supported
fixed partial
denture
Scaler tips are designed to fit the curvature of
the standard abutment.
99

100. Prophy paste and a
rubber cup on a prophy
head / handpiece can be
used to polish implant
bars when removal is not
indicated
100

101. Failure of implant has a multi-factorial dimension.
Often many factors come together to cause the ultimate
failure of the implant. One needs to identify the cause
not just to treat the present condition but also as a
learning experience for future treatments. Proper data
collection, patient feedback, and accurate diagnostic tool
will help point out the reason for failure. An early
intervention is always possible if regular check-up are
undertaken.
As someone well said, it is not how much success we
obtain, but how best we tackle complex situations and
failures, that determine the skill of a clinician. No,
doubt, failures are stepping stones to success but not
until their etiologies are established and their
occurrence is prevented.
Conclusion…
101

102. Misch : Contemporary implant dentistry
Atlas of implant dentistry, Cranin
Why do dental implants fail: part I : Askary et al
ID 1999 vol8 no2 173-183
Why do dental implants fail: part II : Askary et al
Id 1999 vol 3 : 265-275
A.S.Sclar; Soft tissue & esthetic considerations in
implant dentistry.
Myron Nevins; Implant therapy.
Torosian J, Rosenberg ES. The failing and failed
implant: a clinical, microbiologic, and treatment
review. J Esthet Dent. 1993.
Failures in implant dentistry.W. Chee and S. Jivraj.
British Dental Journal 202, 123 - 129 (2007)
REFERENCES
102

103. Yoav Grossmann. Prosthetic treatment for severely
misaligned implants: A clinical report. J Prosthet
Dent 2002;88:259-6.
Goodacre C J, Bernal G, Rungcharassaeng K, Kan J
Y. Clinical complications with implants and implant
prostheses. J ProsthetDent 2003; 90: 121–132.
Effect of implant size and shape on implant
success rates: A Literature review JPD
2005;94:377-81
WWW.google.com
103

104. 104