2. CONTENTS
• Introduction
• Definitions
• Probable Factors Affecting Implant Failures
• Warning Signs Of Implant Failure
• When To Say An Implant Has Failed?
• Criteria For Implant Success
• Success And Failure Statistics
• Revised Criteria For Implant Success
• Parameters/Diagnostic Criteria Used For Evaluating
Failing Implants
4. INTRODUCTION
• Some implants will fail. This can be devastating to
the patient as well as the dentist.
• There is an increased demand for dental implants due
to a heightened awareness in the general public about
this treatment alternative.
• Due to the vast number of publications demonstrating
the high predictability of this type of treatment,
dentists are offering implant therapy to their patients
more than ever before .
5. INTRODUCTION
• Dental implants are now considered the standard of care
for fully edentulous patients and single edentulous spaces.
• Many clinicians and patients are opting for extracting
teeth with poor prognosis or poor esthetics and replacing
them with implant supported prostheses.
• At the same time we are finding an increasing number of
reports about biologic and mechanical complications.
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 if goes wrong.
6. ………When implant fails……then……….
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!’
8. DEFINITIONS
• Implant failure: Implant failure is defined as the
total failure of the implant to fulfill its purpose
(functional, esthetic or phonetic) because of
mechanical or biological reasons.
• Iatrogenic failure: Iatrogenic failure is one
characterized by a stable and osseointegrated implant,
but due to malpositioning it is prevented from being
used as part of the anchorage unit.
9. DEFINITIONS
• Biologic failure: Biological failure can be defined as the
inadequacy of the host tissue to establish or to maintain
osseointegration.
• Ailing implants Ailing implants are those showing
radiographic bone loss without inflammatory signs or
mobility.
• An implant that may demonstrate bone loss with deeper
clinical probing depths but appears to be stable when
evaluated at 3−4 months interval.
10. DEFINITIONS
• Failing implants Failing implants are characterized
by progressive bone loss, signs of inflammation and
no mobility.
11. DEFINITIONS
• Failed implants Failed implants are those with
progressive bone loss, with clinical mobility and that
which are not functioning in the intended sense.
• An implant that demonstrates clinical mobility, a peri-
implant radiolucency, and a dull sound when
percussed.
• A failed implant is non-functional and must be
removed.
12. DEFINITIONS
• Surviving implants Surviving is a term described by
Alberktson that applies to implants that are still in
function but have not been tested against success
criteria.
15. Warning signs of implant failure
• 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
(Askary et al ID 1999; vol 8; no2, 173-183)
16. When To Say An Implant Has Failed?
• To make these critical selections, a set of criteria for
success based on scientific investigations is essential.
• Consideration must be given to evaluating the
following criteria:
• mobility
• Bone loss
• Gingival health
• Pocket depth
• Effect on adjacent teeth
17. When To Say An Implant Has Failed?
• Function
• Esthetics
• Presence of infection,
• discomfort, paraesthesia or anesthesia
• Intrusion on the mandibular canal
• Emotional and psychological attitude and satisfaction
of the patient
18. 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)
19. SUCCESS AND FAILURE STATISTICS
• The longitudinal clinical studies have reported a
success rate at 10 years ranging from -
• 81% to 85%, for the maxilla and
• from 98% to 99% for the anterior mandible.
• Esposito et al. reported the biologically related
implant failures calculated on a sample of 2812
implants and found a failure rate of 7.7% over a 5
year period.
20. SUCCESS AND FAILURE STATISTICS
• Bain and Moy (1993), reviewed the outcome of 2194
Branemark implants placed in 540 patients over a 6
year period and reported a failure rate of 5.92%.
• Friberg et al. conducted a study comprising 4641
Branemark dental implants for a period of 3 years and
reported a failure rate of 1.5%.
21. Smith and Zarb have reviewed the success
criteria given by different authors.
chnitman and Schulman
• Mobility less than 1 mm in any direction.
• Radiologically observed radiolucency graded but
no success criterion defined.
• Bone loss not greater than one third of the
vertical height of the bone.
• Gingival inflammation amenable to treatment.
• Functional service for 5 years in 75% of patients.
22. Chainin, Silver Branch, Sher, and Salter
In place for 5yrs/ 60 months or more.
• Lack of significant evidence of cervical saucerization
on radiographs.
• Freedom from hemorrhage according to Muhelman’s
index.
• Lack of mobility.
• Absence of pain and tenderness.
• No pericervical granulomatosis or gingival
hyperplasia.
• No evidence of a widening peri-implant space on
radiograph.
23. Mckinney, Koth, and Steflik
Subjective criteria
• Adequate function.
• Absence of discomfort.
• Patient belief that esthetics, emotional, and
psychological attitude are improved.
24. Mckinney, Koth, and Steflik
Objective criteria
• Good occlusal balance and vertical dimension.
• Bone loss no greater than one third of the vertical
height of the implant, absence of symptoms and
functionally stable after 5 years.
• Gingival inflammation managable to treatment.
• Mobility of less than 1 mm buccolingually,
mesiodistally, and vertically.
25. Mckinney, koth, and steflik
• Absence of symptoms and infection associated with the
dental implant.
• Absence of damage to adjacent tooth or teeth and their
supporting structures.
• Absence of parasthesia or violation of mandibular
canal, maxillary sinus, or floor of nasal passage.
• Healthy collagenous tissue without polymorphonuclear
infiltration.
26. Mckinney, Koth, and Steflik
Success criteria
• Provides functional service for 5 years in 75%
of implant patients
27. Revised criteria for implant success
Alberktson, Zarb, Washington, and Erickson
• Individual unattached implant that is immobile when
tested clinically.
• Radiograph that does not demonstrate evidence of
periimplant radiolucency.
• Bone loss that is less than 0.2 mm annually after the
implant’s first year of service.
28. Revised criteria for implant success
Individual implant performance that is characterize by
an absence of
persistent and/or irreversible signs and symptoms
of pain,
• infections,
• necropathies,
• paraesthesia, or violation of the mandibular canal.
29. Revised criteria for implant success
In content of criteria mentioned, a success rate of
• 85% at the end of a 5-year observation period and
• 80% at the end of 10-year observation as a minimum
criterion for success.
30. Further, in 1998 Esposito et al.
According to them –
• absence of mobility and an average radiographic
marginal bone loss of less than 1.5 mm during the first
year of function and less than 0.2 mm annually
thereafter,
• absence of pain/parasthesia were to be considered
success criteria for osseointegrated implants.
• It was also suggested that probing depths related to a
fixed reference point and bleeding on probing should
be measured.
31. Parameters Used For Evaluating Failing
Implants
1. Clinical signs of early infection
2. Pain or sensitivity
3. Clinical discernible mobility
4. Radiographic signs of failure
5. Dull sound at percussion
6. Bleeding on probing
7. Absence of keratinized mucosa
32. Parameters used for evaluating failing
implants
1.Clinical signs of early infection:
During the healing period (3−9 months) complications
such as-
• swelling,
• fistulas,
• suppuration,
• early/late mucosal dehiscences, and
• oseteomyelitis,
33. Parameters used for evaluating failing
implants
1.Clinical signs of early infection:
• Signs of infection occurring during at an early stage
of healing is more critical than if they occur at a
later stage.
Reason:
• the infection occurring at an early stage will lead to
disturbance in the osseointegration of the implant to
the surrounding bone.
34. Parameters Used For Evaluating Failing
Implants
2. Pain or sensitivity
• Pain or discomfort is often associated with mobility
and could be one of the first signs which indicate an
implant failure.
35. Parameters Used For Evaluating Failing
Implants
3.Clinical discernible mobility:
• Mobility is always a clear sign of failure.
• The implant must be suspected to be surrounded by a
fibrous tissue capsule.
36. Parameters Used For Evaluating Failing
Implants
Several different types of mobility have been recognized
as follows
• Rotation mobility
• Lateral or horizontal mobility
• Axial or vertical mobility.
• Occasionally, clinically discernible mobility can be
present without distinct radiographic bone changes.
• Therefore, mobility is the cardinal sign of implant
failure.
37. Parameters Used For Evaluating Failing
Implants
4.Radiographic signs of failure
• There can be two well-distinct radiographic pictures:
1. A thin peri-fixtural radiolucency surrounding the
entire implant, suggesting the absence of a direct
bone-implant contact and
2. possibly a loss of stability, and an increased
marginal bone loss.
38. Parameters Used For Evaluating Failing
Implants
• Alberktson et al. have suggested using less than 1.5
mm of marginal bone loss during the 1st year of
loading and thereafter less than 0.2 mm yearly as
success criteria.
• Adell et al. determined that the mean bone loss for
Branemark osseointegrated implants is 1.5 mm for
the first year, followed by a mean bone loss of 0.1
mm per year.
39. Parameters Used For Evaluating Failing
Implants
5. Dull sound at percussion
• It has been suggested that a subdued sound upon
percussion is indicative of soft tissue encapsulation.
• whereas a clear crystallization sound indicates
successful osseointegration.
• Although it is a rather subjective test without a solid
scientific background, it can provide a useful
indication to the examiner.
40. 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
41. 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
periodontis
• Smoking and tobacco use
42. Negative factors
• Unresolved caries,
endodontic lesions,
• Eccentric loading
• Inappropriate early clinical
loading
• Bruxism and other
parafunctional habits
43. Classification Of Implant Failures
1. Classification By Rosenberg Et Al.
2. Classification By Esposito Et Al.
3. Classification By Truhlar And Tonetti And Schmid
4. Classification By El Askary Et Al.
5. Classification By Heydenrijik Et Al.
6. Classification By Nallaswamy
7. Classification By Matukas
48. Biological
• Early or primary (before loading): failure to establish
osseointegration.
• Late and secondary (after loading): failure to maintain
the achieved osseointegration.
• Mechanical
Fracture of implants, connecting screws, bridge
frameworks, coating etc.
• Iatrogenic
Nerve damages, wrong alignment of implants, etc.
• Inadequate patient adaptation Phonetical, esthetical,
psychological problems, etc.
Esposito et al.
Classification by Esposito et al.
49. Esposito et al.
• reviewed the various factors associated with
increased failure rates, based on the present literature
review-
1. Endogenous factors
2. Exogenous factors
54. Truhlar ,Tonetti and Schmid
• Early failures: Those that occur from weeks to few
months after placement caused by factors that
interfere with normal healing process or by an altered
healing response.
• Late failures: Those that arise from pathologic
processes that involve a previously osteointegrated
implant.
55. Early failures
surgical factors
1. Infection: Is one of the many factors contributing to
failure of implants.
The microbial flora is the same that is traditionally
associated with periodontitis.
Truhlar ,Tonetti and Schmid
56. surgical factors
2. Staphylococcus aureus is demonstrated to have the
ability to adhere to titanium surfaces. This may be
significant in the colonization of dental implants and
subsequent infection.
Truhlar ,Tonetti and Schmid
Early failures
57. • 2) Dehiscence and fenestrations of the implant site:
Reasons:
• when implants are placed in a prosthesis guided axis position .
• Not enough wound closure that may allow a primary scarring.
Solution:
• It is necessary for the design and the management and release of
the flap to allow a under extension and thus achieve a better
cover and tension free surgical site
surgical factors
Truhlar ,Tonetti and Schmid
Early failures
58. 3) Malposition/angulation of implant:
Positional Issues- Bucco-lingual Malposition
Positional Issues- Mesio-distal Malposition
surgical factors
Truhlar ,Tonetti and Schmid
Early failures
59. surgical factors
Truhlar ,Tonetti and Schmid
Early failures
Positional Issues- Bucco-lingual Malposition:
Buccally malpositioned implants can jeopardize labial
cortical plate of the bone & cause mid - buccal
recession and produce an unesthetic result.
Solution:
Jumping distance of upto 2mm has to be maintained to
account for bone loss.
Malposition/angulation of implant:
60. surgical factors
Truhlar ,Tonetti and Schmid
Early failures
Malposition/angulation of implant:
Positional Issues- Mesio-distal Malposition:
Too little space may cause injury to interproximal bone
and soft tissue and will necessitate restorations that are
smaller than usual.
If there is too much space between implants
additional pontic can be cantilevered however that will
increase stress on the supporting implants.
61. surgical factors
Truhlar ,Tonetti and Schmid
Early failures
Malposition/angulation of implant:
• Angulation Issues-
• Angulation of 15o or less is
acceptable
• However if it approaches or
exceeds 25O
62. surgical factors
Truhlar ,Tonetti and Schmid
Early failures
Malposition/angulation of implant:
The inclination will introduce a bending moment on the
implant and will lead to potential biomechanical
problems like
• restoration fracture,
• screw fracture,
• abutment fracture,
• implant body fracture,
• osseous destruction cause of unfavorable loading
• plaque accumulation under ridge lap pontics.
63. Early failures
• Reasons Why An Implant Lacks Primary
Stability-
1. Over preparation of the site with excessive in and
out motion during drilling.
2. Use of dense bone drills in low density bone.
3. Following an elliptical /imprecise pathway during
drilling.
4. If the insertion torque is < 10 Ncm
5. Whereas a too high torque value (>45 Ncm) could
lead to bone compression
surgical factors
Primary stability
Truhlar ,Tonetti and Schmid classification
64. Early failures
• According to a study conducted by Cooper in
2010, on 1084 implants.
• There was a 6.43 fold lower risk of primary implant
stability failure in anterior mandible than any other
location.
• Maxilla had 2.7 fold higher risk of primary stability
failure versus Mandible.
• Females had 1.54 higher risks of primary implant
stability failures versus men.
surgical factors
Primary stability
Truhlar ,Tonetti and Schmid classification
65. Late Failures:
1. Mandibular fractures:
• The central area of the Mandible has a greater
risk for this complication since it has poor
vascular irrigation.
• The bone in the area becomes sclerotic and
undergoes severe resorption due to long period
of edentulism and also due to pressure exerted
by the prosthesis
Truhlar ,Tonetti and Schmid classification
66. Late Failures:
2. Infections:
• An imbalance in the host parasite equilibrium can
manifest itself in a inflammatory changes leading to
two distinct clinical conditions:
1. A lesion limited to the superficial soft tissues (peri-
implant mucositis)
2. A lesion involving deeper soft tissues and eventually
the marginal portion of bone implant interfaces
(periimplantitis)
Truhlar ,Tonetti and Schmid classification
67. Difference between peri-implant lesions and
periodontal lesions
Peri Implant Lesions Periodontal lesions
Histomorphometric analysis
shows
apical spread of infiltrated
connective tissue from gingival
margin is 1.3mm
0.9mm apical spread of
infiltrated
connective tissue
According to Brandes et al
rate of
tissue destruction is higher.
Rate of tissue destruction is
lower
68. Peri Implant Lesions Periodontal lesions
According to lindhe clinical &
radiographic signs of
radiological destruction were
more pronounced at
implants.
Not that well appreciated
Less vascular structures
observed.
More vascular structures
observed.
Peri-implant infiltrate was
predominated
by neutrophils & plasma cells.
Periodontal infiltrate was
predominated by Macrophages
& lymphocytes
69. Predisposing conditions that may lead to peri-
implantitis.
1. Infection from activation of residual bacteria in sites
with history of endodontic pathology.
2. Infection from scar tissues following removal of an
impacted tooth.
3. In contamination from adjacent tooth with endodontic
pathology/periodontal conditions.
4. Apical entrapment of gingival epithelial cells during
implant insertion.
5. Necrosis from excessive heating of bone during
osteotomy drills.
70. Late Failures: Peri-implantitis.
There are two types of Peri-implantitis.
• - Infected type
• - Non infected /active type
Symptoms:
• Pain, redness, tenderness upon touching the face
over the apical area of the implant, swelling ,peri-
apical radiolucency at apex of implant & fistulous
tract.
periimplantitisTruhlar ,Tonetti and Schmid classification
71. • Management: Should be taken up as soon as
possible to prevent acute exacerbation of lesion and
total loss of osteointegration.
1.Surgical management Steps
• · Flap elevation
• · Creation of a bony window
• · Debridement & curretage
• · Removal of apical portion of infected implant.
• This is indicated primarily in cases where implant
extends into maxillary sinus / nasal cavity
periimplantitis
72. Late Failures:
2.Surface Treatment: with 250mg tetracycline powder with sterile
water for 1 min, the area then rinsed & flushed.
• The procedure repeated through Grafting.
3.Medication:
• systemic antibiotics such as penicillin G/amoxicillin (500mg
ds for 7 days) along with chlorhexidine 0.12% rinse for 3
weeks recommended after surgical intervention.
periimplantitisTruhlar ,Tonetti and
Schmid classification
73. Late Failures
• 3. Implant displacement:
Implant could undergo a displacement at any
time after cover-screw being placed (osseointegration
period) or ever after attaching the healing abutment.
• Guller and delilbasi reported a case in which
implant migrated into the sinus cavity after 8 years.
Truhlar ,Tonetti and
Schmid classification
74. • Post operative complications of implant displacement
into maxillary sinus include:
1. Asymptomatic implant displacement
2. Reactive sinusitis and/or
3. Associated oroantral communication
4. The fixations could displace from Maxillary sinus and
into spheroidal & ethmoidal sinus.
5. Migration that ended in the orbital floor has also been
seen that ended up lodged between bone and inferior
rectus orbital muscle causing pain & diplopia.
3. Implant displacement:
Truhlar ,Tonetti and Schmid
classification
75. Late Failures
4. Implant Fractures:More than 80% fractures are located
in the molar & premolar regions and mostly occur 3-4
years after being loaded.
Truhlar ,Tonetti and
Schmid classification
76.
77. Late Failures
4. Implant Fractures:
• Causes:
1. Defects in implants design/materials used in their
construction.
2. Connecting implants to teeth.
3. Occlusal overload & parfunctional habits.
4. Non passive union between implant and prosthesis or
5. special cantilever in fixed prosthesis, At each
increment of 5mm in cantilever length stress increased
by 30-37% on cortical bone around the implant.
Truhlar ,Tonetti and Schmid
classification
78. Late Failures Implant
Fractures
• From the studies conducted by finite element.
1. The stiffer the cancellous bone, more stress it takes and less
stress on cortical bone.
2. Slight – decrease in stress was observed with longer implant
and abutments.
3. Use of Co-Cr alloy contributes to better stress distribution.
Truhlar ,Tonetti and
Schmid classification
79. Implant Fractures -
connecting teeth to implants
Technical problems are
• Implant fracture
• Tooth inclusion
• Cement bond breakdown
• Abutment tooth fracture
• Abutment screw loosing
• Prosthesis fractures
Truhlar ,Tonetti and Schmid classification Late Failures
80. Implant Fractures -
connecting teeth to implants
Biologic Problems
• Peri-implantitis
• Endodontic problems
• Loss of abutment tooth
• Loss of an implant
• Caries
• Root fracture
Truhlar ,Tonetti and Schmid classification Late Failures
81. Implant Fractures -
connecting teeth to implants
• Occlusal Risk Factor: Occlusal overload is one of main
causes for peri-implant – bone loss and implant prosthesis
failure due too crestal bone loss, thus increasing anaerobic
sulcus depth and peri-implant disease states.
solution:
1. Implant protected occlusion developed by Misch
2. Provision of load sharing occlusal contacts.
3. Modification of occlusal table & anatomy
4. Increased Implant surface area.
Truhlar ,Tonetti and Schmid classification Late Failures
83. Classification by El Askary et al.
1. Based on etiology:
• Failures because of host factors
• Restorative factors
• Surgical placement of implant
• Implant selection
84. Classification by El Askary et al.
Failures because of host factors
• Medical status – Osteoporosis and other bone
diseases; uncontrolled diabetes.
• Habits – smoking, para-functional habits.
• Oral status – poor home care juvenile, and rapidly
progressive periodontitis, irradiation therapy.
85. Classification by El Askary et al.
Restorative factors
• Excessive cantilever,
• pier abutments,
• no passive fit,
• Improper fit of the
abutment,
• improper prosthetic
design,
• improper occlusal
scheme,
• bending moments,
• connecting implants to
natural dentition,
• premature loading,
• excessive torquing
86. Classification by El Askary et al.
Surgical placement of implant
• Off axis placement (severe
angulation)
• Lack of initial stabilization
• Impaired healing and infection
because of improper flap
design or others.
• Overheating the bone and
exerting too much pressure.
• Minimal space between
implants
• Placing the implant in
immature bone grafted sites.
• Placement of the implant in an
infected socket or a pathologic
lesion.
• Contamination of the implant
body before insertion.
87. Classification by El Askary et al.
Implant selection
• Improper implant type in improper bone type.
• Length of the implant (too short, crown–implant
ratio unfavorable)
• Diameter of the implant.
88. Classification by El Askary et al.
2. 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.
El Askary et al.
89. Classification by El Askary et al.
3. According to timing of failure
• Stage I surgery
• At stage II
• After restoration.
El Askary et al.
90. 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 stagesurgery El Askary et al.
91. Secondstagesurgery+ abutmentconnection
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 osseointegration Remove the implant
Difficulty inserting a
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;
Open the area and
disinfect with chlorhexidine.
If the lesion is too large,
consider a bone regeneration
or grafting technique
El Askary et al.
92. Prosthetic problems
Problem Possible causes Solutions
Pain or sensation
when tightening the
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.
El Askary et al.
93. 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
Retrieval of screws.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)
Prosthetic problems
Problem Possible
causes
Solutions
El Askary et al.
95. Cavitron and instrumentation
• Artery forceps, explorers, spoon excavators, and Cavitrons
have been used when the screw fracture occurs in the coronal
third of the implant chamber.
• The oscillations from an ultrasonic scaler can gradually
reverse out the screw by placing the thin tip of an ultrasonic
scaler directly on the top of the screw.
• Adding a lubricant, such as eugenol or mineral oil, can
decrease friction and ease clamping to assist in screw retrieval.
96. High- and low-speed handpieces
• With a high-speed handpiece equipped with a diamond
bur,
• prepare a 1 mm slot across the most occlusal portion of
the broken screw fragment.
• Hold the handpiece firmly to avoid having the bur
inadvertently jump into the implant body.
• Use an appropriate-sized mini flat-end screwdriver and
reverse out the screw.
97. 2-low-speed handpieces
• A low-speed contra-angle handpiece with a one-
quarter round carbide bur running in a reverse mode
could help spin out the screw.
• The small round drill acts as a screwdriver and holds
the head of the fragment.
98. No. 3—Screw retrieval kit
• There are many different types of screw/implant
retrieval and rescue kits made by different companies.
• Nobel Biocare,
• Neobiotech,
• Osstem (OssVK),
• BTI Biotechnology Institute, and
• Salvin Dental Specialties
100. Steps
Insert the appropriate drill guide onto the implant
platform.
Use a contra-angle handpiece with the pilot drill at
1,000–1,250 RPM in reverse with a pumping motion and
copious irrigation to create a 1–2 mm deep dimple into
the fractured screwhead.
This creates a purchase point for the next drill tap.
Suction the metal shavings and irrigate the area.
While still in reverse, use the tap drill at 70–80 rpm,
which will reverse out the broken screw from the
screw chamber.
101.
102. 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
Problem Possible
causes
Solutions
El Askary et al.
103. 1. Continuing
bone loss around
one or more
implants
Infection
(peri-
implantitis)
Occlusal
overload
Remove the etiolgical factors
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 proced
Ure
Modify the prosthetic design
Problem Possible
causes
Solutions
Prosthetic problems El Askary et al.
104. Classification by El Askary et al.
4. According to condition of failure: (clinical
an radiographic status)
• Ailing implants
• Failing implants
• Failed implants
• Surviving implants.
105. 5. According to responsible personnel
• Dentist (oral surgeon, prosthodontist,
periodontist)
• Dental hygienist
• Laboratory technician
• Patient
Classification by El Askary et al.
106. Classification by El Askary et al.
6. According to failure mode
• Lack of osseointegration (usually mobility)
• Unacceptable esthetics
• Functional problems
• Psychological problems.
107. Classification by El Askary et al.
7.According to supporting tissue type
• Soft tissue problems (lack of keratinized tissues,
inflammation, etc.)
• Bone loss (Radiographic changes, etc.)
• Both soft tissue and bone loss.
108. Heydenrijik et al. Classification
• Early failures
• Osseointegration has never been established, thus
representing an interference with healing process.
• Late failures
• Osseointegration not maintained implying processes
involving loss of osseointegration.
• Soon late failures
• Implants failing during the first year of loading.
• Delayed late failures
• Implants failing in subsequent years.
111. Hobo et al. complications
I. 1. Complications in Stage I surgery.
2. Complications in Stage II surgery.
3. Prosthetic complications.
II. Hobo et al. (Beumer,Moy)
1. Loss of bone anchorage
a) Mucoperiosteal perforation
b) Surgical trauma
112. II. Hobo et al. (Beumer,Moy)
• 2. Gingival problems
• a) Proliferative gingivitis
• b) Fistula formation
• 3. Mechanical complications
• a) Fracture of prostheses, gold screws,
abutment screws
113. Hobo et al.listed out the various complications
occurring in implants as follows:
114. Hobo et al.listed out the various complications
occurring in implants as follows:
115. Hobo et al.listed out the various complications
occurring in implants as follows:
117. …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 post insertion;
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……
118.
119. Hygiene aids……
Super - floss
End tufted brushes
Proxy brushes
Tartar control dentrifices
Mechanical instruments
120. Super - Floss
Excellent for all types of
implant restorations
Butler Post Care Floss
Aid
Excellent for implant
bars and fixed hybrid
prostheses.
122. 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…
124. Prophy paste and a rubber
cup on a prophy head /
handpiece can be used to
polish implant bars when
removal is not indicated
125. Conclusion
• 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
diagnostictool will help point out the reason for failure.
126. Conclusion
• 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.
127. References
• 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
• 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)
• Dealing with dental implant failures, J Appl Oral Sci. 2008;16(3):171-5
• Da Costa GC, Aras M, Chitre V. Failures in Dental Implants. J Adv Med
Dent Scie 2014;2(1):68-81.
• Implant failures Prashanti, et al. Indian Journal of Dental Research, 22(3),
2011
• Kate MA, Palaskar S, Kapoor P. Implant failure: A dentist's nightmare. J
Dent Implant 2016;6:51-6.
