Dental implant failure / /certified fixed orthodontic courses by Indian dental academy

DENTAL IMPLANT
FAILURES

INDIAN DENTAL ACADEMY
Leader in Continuing Dental Education
www.indiandentalacademy.com


CONTENTS
• Introduction
• Systemic factors contributing to implant failure
• Osseointegration
• Systemic influences on alveolar bone
• Osteoporosis
• Psychosocial factors influencing implant
success
• Errors in maintaining sterility
• Errors due to implant contamination
• Errors in surgical technique
• Errors in implant positioning
• Errors in implant exposure
• Pitfalls in implant dentistry from a laboratory
perspective

• Prosthetic salvage of surgical misadventures
in implant placement
• Prosthodontic considerations in first stage
implant failures
• The influence of tobacco use on endosseous
implant failures
• Implant design and manufacturing as
predictors of implant failure
• Soft tissue conditions influencing implant
failure
• Microbiologic contribution to soft-tissue health
• Microbiologic mechanism for implant failure
• Peri - implantitis
• Diagnosing the failing implant
• Predictors of failure
• Treating the failing implant
• Conclusion

Biology of Osseointegration (Branemark)


• Albrektson describes the physiologic
conditions that are required for
osseointegration, including
• adequate bone cells to achieve bone healing,
• adequate nutrition to these cells (blood
supply), and
• adequate stimulus for bone repair.
• When these conditions are present,
osseointegration can be achieved with a high
degree of success.


INTRODUCTION
• The goal of implant therapy is to provide
long-term replacement for missing
dentition on ideally positioned
osseointegrated implants.
• Advances in radiographic imaging,
splint construction, bone regeneration
capabilities, and soft-tissue
reconstruction permit placing implants
predictably in acceptable positions.

• Surgery for dental implants is a
procedure with a high rate of
patient success defined as
providing a viable implant-
supported prosthesis that
satisfies the patient.

• However, as with any medical
procedure, failures occur.


• In a few cases, acceptable surgical and
prosthetic outcomes do not meet with
satisfaction from the patient.
• Such failures probably often have little to do
with the implant team's technical
competence.
• As with most complex reconstruction
procedures that involve a degree of
collaboration between an imlantologist and a
patient, patient factors that influence the
imlantologist - patient relationship and the
patient's compliance with imlantologist
requests may play a key role in this
procedure's ultimate success.

• An implant or a tooth diagnosed as a clinical
failure is easier to describe than is a success.
• Signs and symptoms of failure for an implant are

• 1) horizontal mobility beyond 0.5mm or any clinically
observed vertical movement under less than 500 g force,
• 2) rapid progressive bone loss regardless of the stress
reduction and periimplant therapy,
• 3) pain during percussion or function,
• 4) continued uncontrolled exudate in spite of surgical
attempts at correction,
• 5) generalized radiolucency around an implant,
• 6) more than one half of the surrounding bone is lost
around an implant, and
• 7) implants inserted in poor position , making them useless
for prosthetic support.

CLASSIFICATION
• Based on the cause of implant
failure
• Preoperative
• Intra operative
• Post operative


PREOPERATIVE
• Patient Selection
• Comprehensive treatment with
osseointegrated implants begins
with patient evaluation and
selection.
• Considerations should be given to
chronic illnesses because they
contribute to reduced organ
reserve and the patient's ability to
have the surgical placement of
implants.

• Matukas reviewed potential medical
risks associated with surgery for dental
implants. He reviewed several diseases
that potentially can reduce organ
reserve
Cardiovascular
Heart failure
Coronary artery disease
Hypertension
Unexplained arrhythmia
Respiratory
Chronic obstructive pulmonary disease
Asthma www.indiandentalacademy.com

• Gastrointestinal
• Nutritional status
• Hepatitis
• Malabsorption syndrome
• Inflammatory bowel disease

• Genitourinary
• Chronic renal failure

• Endocrine
• Diabetes
• Thyroid disease
• Pituitary/adrenal disease

• Musculoskeletal
• Arthritis
• Osteoporosis

• Neurologic
• Stroke
• Palsy
• Mentation


• Fonseca and Davis have recommended that absolute
medical contraindications to endosseous implant surgery
include

• Pregnancy,
• Granulocytopenia,
• Steriod use,
• Continous antibiotic coverage,
• Brittle diabetes,
• Hemophilia,
• Ehlers-danlos syndrome,
• Marfan's syndrome,
• Osteoradionecrosis,
• Radiation, renal failure,
• Organ transplants,
• Anticoagulant therapy,
• Fibrous dysplasia, and
• Crohn's disease.

Relative contraindications.

• Infectious hepatitis,
• Recent myocardial infarction,
• Blood dyscrasias,
• Uncontrolled diabetes,
• Severe alcoholism,
• Chronic steroid use,
• Renal diseases, and
• Uncontrolled metabolic disorders


• Zeitler and Fridrich reported that tissue
perfusion and microvascular diseases
have an important role in wound healing.
• In their report, they described the
importance of tissue oxygenation and
oxygen tension as they relate to tissue
perfusion as factors in tissue healing.
• Systemic diseases such as diabetes
mellitus and collagen diseases such as
scleroderma, systemic lupus
erythematosus, rheumatoid arthritis, and
Sjogren's syndrome have microvascular
changes that can cause decreased
oxygenation due to poor vascularity and
have poor wound healing potential.

• Evidence suggests that bone disorders
such as osteoporosis may compromise
the success of dental implant placements
that require preliminary bone building.
• Albrektsson has outlined the response of
bone tissue to endosseous implants.
• He describes the physiologic conditions
that are required for osseointegration,
including adequate bone cells to achieve
bone healing, adequate nutrition to these
cells (blood supply), and adequate
stimulus for bone repair.

• Albrektsson also states that there is a
"primary interference to integration."
• These include traumatic surgery, in
which the frictional heat generated
during placement of the implant causes
necrosis of the surrounding cells and
causes a lack of healing and integration.
• The second interference to bone
integration is an implant bed of low
healing potential.
• What can cause an implant
recipient site of low healing
potential?
• Albrektsson states that there are some
indications that various systemic
diseases such as rheumatoid arthritis
negatively influence osseointegration.

THE INFLUENCE OF TOBACCO USE ON
ENDOSSEOUS IMPLANT FAILURES

• It has been shown that dentate
smokers have a higher incidence and
greater severity of periodontal disease
and that smokers treated with dental
implants have a greater risk of
developing peri-implantitis.
• a case was reported on the relation of
smoking to impaired intraoral wound
healing and the loss of endosseous
implants.

PSYCHOSOCIAL FACTORS
INFLUENCING IMPLANT SUCCESS
1. Patients who lack external support (financial,
social).
2. Patients who lack the cognitive capacity (or skill
capacity).
3. Patients who have emotional problems.
4. Patients who have a pattern of interpersonal
problems
5. Patients who consistently engage in behaviour
6. Patients who maintain general health and illness
attitudes and beliefs.

ERRORS DUE TO ANATOMIC
VARIATIONS AND ABNORMALITIES

• Ideal fixture placement depends
on a detailed preoperative clinical
assessment of bone
configuration, quality, and
quantity.

• Periapical and panoramic
radiographs of the maxilla and
mandible usually provide
additional methods to assess
bone conditions.

• Periapical views are necessary when the
implant is to be placed in approximation to
the natural dentition.
• Intraoral dental radiographs accurately
locate the position of the adjacent roots and
help to avoid iatrogenic injury to these
structures.
• When necessary, lateral cephalometric
radiographs as well as CT provide additional
cross-sectional information on bone height
and anatomic configuration.

• Relation to the inferior alveolar nerve
• Relation to the mental nerve
• The bone immediately surrounding the
region of the nasal cavity and
maxillary sinus is often thin, and these
areas may be penetrated accidentally
when placing implants.
• The lingual aspect of the mandible in
the molar region is another area in
which errors in implant placement can
occur.

• Bone quality ranges from dense, compact,
and relatively avascular bone to cancellous
bone with a spongy texture.
• The type of implant design selected should
match the quality of bone into which it is
placed.
• Press-fit implant design -high percentage of
cancellous bone.
• Pretapped implant -bone is dense,
compact, and poorly vascularized.


• Screw-shaped implant design provides
greater surface area for interaction with
the host bone tissue, enhanced initial
stabilization, greater resistance to sheer
forces.
• Primary stability is important for the
bony integration and long-term success
of the implant.


ERRORS IN MAINTAINING
STERILITY
• A proper sterile operating environment
is one of several factors critical to the
achievement of successful osseous
integration.


ERRORS DUE TO IMPLANT
CONTAMINATION
• Contamination of the implant surface
interferes with osseointegration and must
be scrupulously avoided.
• Surgical gloves should be free of powder
residue


• Surface contamination could eliminate
the implant's unique ability to integrate
with the adjacent bone.
• Contaminants can become “the bad
apple in the barrel” and lead to tiny or
even widespread areas of interference
with the osteoblast-titanium oxide
connection interaction.
• Implant site should be irrigated.
• Titanium implants must be carried by
titanium instruments.


ERRORS IN SURGICAL
TECHNIQUE
• Successful implant placement depends
highly on proper surgical technique
• Maintaining an adequate blood supply
• Reducing hard-and soft-tissue surgical
trauma
• Incisions
• Osteotomy technique


• Healthy, viable bone is critical for the
successful integration between the bone and
the implant surface.
• Therefore, heat injury to bone must be
avoided during the drilling process.
• A study by Eriksson and Albrektsson showed
that there should temperature for heat-
induced injury to bone tissue is 470C applied
for 1 minute.
• Temperatures above this level result in bone
resorption and fat cell degeneration.

• Three factors causing overheating of
bone:
• 1) inadequate irrigation at the time of
the implant site preparation,
• 2) generating excess heat by force
torquing the drills into dense bone, and
• 3) using dull drill bits, especially in the
case of dense bone


• Heat-injured bone is replaced by less
differentiated tissue, which is incapable of
the normal adaptive remodeling ability of
bone.
• Additionally, a study showed that the
heating of bone above the critical 47 0C
level significantly affects the bone's ability
to regenerate.
• The capacity of the host site to regenerate
bone is critical for the process of
osseointegration to take place.

How to minimize heat generation
during drilling?
• Using sharp drills
• A gradual increase in drill diameter.
• Drill speed
• Eriksson and Albrektsson have shown that
2000 rpm is the optimal rotational speed for
the creation of endosseous implant sites.
• According to Misch cancellous bone should
be drilled at 800 rpm, whereas dense bone
should be drilled at a speed of 1500 rpm.

• Copious irrigation with chilled normal
saline solution
• Such irrigation not only cools the bone
and drill but also lessens the
accumulation of cutting debris that can
become interposed between the bone
and implant surfaces.
• Eccentric movements of the drill should
be avoided.

• Bone drills that bind and lock during
site preparation should be freed by
reversing direction and should not be
rocked back and forth to disengage
the drill.
• Such movements not only increase
the size of the preparation but also
possible cause for injury and lead to
necrosis of bone cells.

• Countersinking of the implant site is often
necessary to accommodate the flared neck
of the implant, care must be taken when thin
cortical plates are present.
• In this situation, the countersinking drill may
reduce the thickness of the cortex to such
an extent that it devitalized the bone and
leads to early exposure of the implant
surface.
• It also decreases the cortical support
against vertical forces and predisposes the
implant to functional overload.

ERRORS IN IMPLANT
POSITIONING
• An implant may integrate successfully with
the surrounding bone but ultimately be a
clinical failure because it is too poorly
positioned to support a functional prosthetic
restoration.
• Attention to proper intraoperative angulation
as well as maintenance of a parallelism
between implant and between implants and
the natural dentition, contribute to optimal and
successful prosthetic design and function.


• Too far to the buccal or in lingual version may
integrate successfully, this can cause a bone
dehiscence, a lack a bicortical support, and
eventual implant exposure.
• Implants placed in lingual version also can
cause irritation of the mobile tissue in the floor
of the mouth.
• In addition to having proper orientation and
alignment in bone, implants should be placed
a minimum of 2 mm from each other or from
natural teeth.
• This amount of space is necessary for the
formation of an esthetic and anatomically
functional prosthesis.

ERRORS IN IMPLANT
EXPOSURE 6 months are allowed for healing
• Generally 4 to
of an endosseous integration to take place
before the implants are exposed and healing
abutments placed.
• When exposing implants in the anterior maxilla,
the esthetics of future restorations should be
considered because an unesthetic restoration is
also a failure.
• Factors to consider include providing sufficient
soft-tissue bulk for a convex ridge form, creation
of interproximal papillae and proper gingival
contour, and assuring that there is keratinized
gingiva, surrounding the labial aspect of the
crown. www.indiandentalacademy.com

PITFALLS IN IMPLANT DENTISTRY
FROM A LABORATORY
PERSPECTIVE
• Restorative nightmares created by lack of adequate
communication among all implant team members-
restorative, surgical, patient and laboratory-when
treatment planning cases.
• Not being able to meet patients’ expectations of
esthetics and function of implant supported restorations
due to improperly placed implant fixtures.
• Not being able to meet patients’ expectations and
desires for the type of prosthesis, fixed or removable,
because treatment option limitations were not fully
explained by the restoring doctor or not fully understood
by the patient.
• Increased restoration cost-not anticipated but incurred-
when additional components must be bought or made in
attempt to restore improperly placed implants.

PROSTHETIC SALVAGE OF SURGICAL
MISADVENTURES IN IMPLANT
PLACEMENT
• However, if ideal implant position is not
achieved and prosthetic salvage may
be necessary to retrieve the case.
• The ability to correct adverse fixture
angulations for prosthetic reconstruction
is therefore a necessary and important
aspect of implant rehabilitation.


• Slight Angulation
• Moderate angulation


• When complications occur, the
precipitating factors must be
identified and eliminated, if
possible.


IMPLANT DESIGN AND
MANUFACTURING AS PREDICTORS OF
IMPLANT FAILURE
Macroscopic
Structure

Surface Composition
Implant
Success

Microscopic Structure


SOFT TISSUE CONDITIONS
INFLUENCING IMPLANT FAILURE


MICROBIOLOGIC MECHANISM FOR
IMPLANT FAILURE :
• When implants fail due to compromise of the soft
tissues, there is destruction of the biologic seal
similar to the disruption of the perimucosal seal in
periodontitis.
• Because the microflora is similar with diseased
implants and teeth, one could hypothesize that the
mechanism for bone destruction around implants
would be similar to that of teeth.
• However, the literature has not yet definitively proved
this to be true; only through clinical reports and
limited patient series we can make this analogy.


• The destruction of the supporting apparatus of
teeth is through a sequence of events that
involve endotoxin, cytokines, and cells of the
periodontal region.
• Endotoxin is a component of the cell walls of all
gram-negative bacteria, such as those involved
with periodontitis: A. actinomycetemcomitans,
B. forsythus, P. gingivalis, P. intermedia, W.
recta, and oral spirochetes.
• Macrophages are activated by endotoxin and
produce proteases that destroy collagen and
proteoglycans.

• These activated macrophages produce
cytokines such as interleukin-1 (IL-1) and
prostaglandin E2 (PGE2).
• IL-1 acts in an autocatalytic fashion to
stimulate more macrophages and activate
fibroblasts to produce additional proteases
and to produce more PGE2.
• The osteoblast is the target cell of PGE2,
leading to resorption of bone.
• It is likely that these mechanisms are present
in inflammation mediated implant failure. It
follows that treatment of inflamed implants
with bone loss involves detoxification of the
implant surface and removal of endotoxin.


PERI-IMPLANTITIS

• Peri-implantitis : inflammatory changes
confined to the soft tissue surrounding an
implant.
• Peri-implantitis : radiographcially
detectable peri-implant bone loss combined
with a soft-tissue inflammatory lesion that
demonstrates suppuration and probing
depths ≥ 6mm. The process begins at the
coronal aspect of the implant, whereas the
more apical portion remains clinically stable
(osseointegrated).


Microbiology :
• Multiple studies have demonstrated that
maintenance of optimal soft-tissue health
around functioning implants results in a peri-
implant microflora predominated by
streptococci and nonmotile rods.
• This is essentially identical to the microflora
around healthy teeth.
• Putative periodontal pathogens, for example,
Porphyromonas gingivalis, prevotella
intermedia, or spirochetes, were either not
recovered at all or were minor components of
the subgingival flora in healthy sites.


Treatment
• Efforts at decontaminating the pathologically exposed
implant surface fall primarily into one of two broad
categories : mechanical and chemotherapeutic.
• Provide diligent treatment of periodontal conditions in the
natural dentition.
• Observe and correct mechanical cofactors
• Prescribe chlorhexidine mouth rinses
• Prescribe anaerobic and aerobic antibiotic therapy for
several weeks.
• Remove component hardware to manage inflammatory
disease surgically.
• Consider chemical and physical treatment of the fixture.
• Consider guided bone regeneration to restore
lost bone.

What steps can be taken prudently
to salvage a failing fixture?
• Three phases related to the intervention
process are offered:
• (1) observing for predictors of failure,
(2) diagnosing the source of the failure,
and
• (3) treating the condition(s) responsible
for the decline in implant restoration
health.


• Avoid positioning implant heads above the
alveolar ridge crest.
• Develop flaps that are well vascularized and
mobile.
• Observe well-established soft-tissue repair
principles.
• Tightly secure all cover screws.
• Reaffirm dietary laws with the patient.
• Intercept trauma from opposing dentition with
bite splints.
• Apply principles of infection management
early. www.indiandentalacademy.com

• Observe for noncompliance and diet
transgressions.
• Reline or remove poorly fitting interim
prostheses.
• Test for osseintegration (Periotest,
controlled reverse torque).
• Consider dentoalveolar causes
(adjacent teeth, jaw fractures, peri-
implantitis).

• Precisely position healing and permanent
abutments.
• Respond quickly to signs of abutment –
related inflammations.
• Frequently observe transitional appliances for
adequacy and implant.
• Review oral hygiene responsibilities and
techniques.
• Provide oral prophylaxis as often as
indicated.

• Poorly compliant patients require more
frequent professional services.
• Be aware of the average life
expectancy of fixture parts and
attachments.
• Periodically plan re-treatments of the
case to accommodate new
developments.
• Recall periodicity must be
individualized.

CONCLUSION
• Prevention, interception, and recovery are the
watchwords of restoring the failing implant.
• Any adverse findings related to implant
components, peri-implant disease,
radiographic changes, or persistent patient
complaints should be interpreted as
threatening to the life of the implant.
• Problematic patient factors must be
anticipated, compromised surgical or
prosthetic conditions must be recognized, and
acquired implant disease states must be
treated early and vigorously.


• First stage implant failure can be prevented
but not treated. Early second stage failure
may represent a biologic failure or injudicious
technique.
• Late second stage failure is usually a product
of lack of care, mechanical loading, or poorly
understood inflammatory conditions.
• Optimal implant health is the only sure
predictor of future implant well-being.
• An ailing implant is a failing implant. Signs of
adverse developments should prompt an
immediate diagnostic initiative and corrective
action.

THANK YOU

Dental implant failure / /certified fixed orthodontic courses by Indian dental academy

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