dental Implant failures/ dental laser certification

Implant failure
complications
and
maintenance
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.comwww.indiandentalacademy.com

Contents
1. Introduction – terminologies
- signs & symptoms
- success criteria
2. Classification of implant complications
3. Intra- operative complications
4. Immediate postoperative complications
5. Late postoperative complications
6. Prosthetic complications
7. Prosthetic consideration
8. Risk factors
9. Implant maintenance
10 . Conclusion
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Introduction

Definition: An implant failure may be defined as the first
instance at which the performance of the implant, measured in
some quantitative way falls below a specified acceptable level.
Terminologies

Roland Meffert described
FAILING IMPLANT
• Failure process is in early stages and is reversible
• Absence of mobility
• Progressive Marginal Bone loss (Saucerization)
• Peri implant infection
AILING IMPLANT
An implant that may demonstrate bone loss with deeper
clinical probing depths, but appears to be stable when
evaluated at 3-4 months interval.

FAILED IMPLANT
Failure process has reached the irreversible state
- Marginal bone loss reaching the apical 1/3 of implant
-Thin peri fixtural radiolucency
- Mobility of implant

Signs and symptoms of implant failure
Horizontal mobility beyond 0.5mm or any clinically observed
vertical movement under <500g force
Rapid progressive bone loss regardless of the stress reduction
and peri implant therapy
Pain during function or on percussion
Continued exudation in spite of surgical attempts at correction

Generalized radiolucency around an implant
Greater than one half of the surrounding bone is lost
around an implant
Pocket depth of 5mm and increasing
Bleeding index of 2 or above
Implants inserted in poor position making them useless for
prosthetic support

Albrektson and Zarb G (1986)
1) The individual unattached implant should be immobile when
tested clinically
2) The radiographic evaluation should not show any peri-
implant radiolucency
3) Vertical bone loss around the fixtures should be less than
0.2mm annually after first year of implant loading.
4) The implant should not show any sign and symptom of pain,
infection, neuropathies, parasthesia, violation of mandibular
canal and sinus drainage.
Success criteria of implants

•MISCH
•Implant quality scale of 1,2, or 3 with a survival rate better than
90%
•Prosthesis survival rate better than 90% at 10 y
•Implants that are supporting a prosthesis
5) Success rate of 85% at the end of 5 year observation period
and 80% at the end of 10 year service.
Smith and Zarb (1989)
6) Implant design allow the restoration satisfactory to patient
and dentist.

Classification of implant
Failures/ Complications

1. ACCORDING TO BRANEMARK et al
Loss of bone anchorage
• Mucoperiosteal perforation
•Surgical trauma
Gingival problems
• Proliferative gingivitis
• Fistula formation
Mechanical complications
• Fixture fractures
• Fracture of prostheses, gold screws, abutment
screws

2. ACCORDING TO MISCH AND JIVIDEN
Time Cause
Surgical failure Stage 1 surgery Surgical complication
Osseous healing failure Healing phase to stage Trauma (heat–surgery)
healing micromotion ,
infection
Early loading failure First year prosthetic
loading (transitional
prosthesis)
Overload/ bacteria
Intermediate failure Year 1 until year 5 in
function
Overload /bacteria
Late failure Year 5 until year 10 in
function
_
Long –term failure >10 years in function _

3. ACCORDING TO NORMAN CRANIN (ATLAS OF ORAL
IMPLANTOLOGY)
Intraoperative complications , surgery only
Short term complications ( those that occur
during the first 6 months ), postsurgery,
during healing)
Long term complications

4.ACCORDING TO W. CHEE AND S.JIVRAJ (BDJ 2007 ;202)
Loss of integration
Positional errors
Soft tissue defects
Biomechanical failures

5.ACCORDING TO HUBERTUS SPIEKERMANN et al
Surgical complications
1) Intraoperative complications
2) Postoperative complications
Immediate complications
Late complications
Prosthetic complications

Intra-operative complications
• Hemorrhage
• Nerve injury
• Perforation of the maxillary or nasal sinus
• Jaw fracture
• Consequences of improper implant placement technique
 Osseous dehiscence
 Osseous perforation
 Damage to adjacent teeth

 Insufficient primary stability
 Severe angulations
 Minimal space between the implants

1. Haemorrhage
Copious arterial or venous hemorrhage
Sites
Inf. Alveolar artery
Lingual artery
In maxilla

Anareawithinthebonethatcansafelysupportimplantswithoutfearof
impingementonthemandibularneurovascularbundle.
GivenbyMISCH(1980)
DeterminedonOPGorclinically
ZoneofSafety

Sublingual haematoma

2
Treatment protocol
Digital pressure
Vessel damage

2. Nerve injury
•Inferior alveolar nerve
•Mental nerve
•Lingual nerve
Site
Treatment protocol

Liu et al (2009)
OPG classification of the course of the nerve
Linear Spoon shaped Elliptic Turning curvature

Mental Foramen and Nerve
Anterior loop – IAN courses inferiorly and
anteriorly and then loops back to emerge from
the foramen.
Incase of an anterior implant
longer than the safety distance –
6mm anterior to foramen

PRECAUTIONS TO BE TAKEN TO AVOID NERVE DAMAGE
relieving incisions
crestal incisions
Adequately expose , identify & protect the nerve
Plan carefully
Avoid thermal damage
Allow safety margins for
a margin bone of no less than 2mm tip and canal
measurement error
drills might overcut 1-2mm more than planned

3. Perforation of the maxillary or nasal sinus

Tests

Treatment protocol

Maxillary sinusitis
symptoms investigation
treatment

PERFORATION OF THE NASAL MOCOSA

4. Jaw fracture
- Rare
Cause
Treatment

2
5. Consequences of improper implant
placement technique:
1. Osseous Dehiscence / perforation

2. Damage to the adjacent structures
The adequacy of the height & width of the interradicular
bone is checked carefully using panoramic radiographs with
stents in situ( metal spheres), periapical films,& millimeter
gauges in the potential implant site & on the adjacent teeth.
OSTEOTOMY
Direct tooth
PDL

3
3. Severe angulations
Significance
Improper implant placement compromises aesthetics and
function

4. Minimal space between implants
A space of 3-5mm between implants to allow biologic
space to avoid necrosis due to blood supply impairment
To maintain proper oral hygiene protocol
Denser the bone more the space required
Space of 1.5 mm between implant and adjacent teeth to
avoid impairment of blood supply to PDL
-Prosthesis contour
-Oral hygiene
-Damage adj. structures

5. Insufficient primary stability
•The most important prerequisite
• single- stage implants
• two- stage system
achieve “secondary” stabilization by choosing a longer
implant or by lengthening the non- loaded healing time.
(Lekholm 1985).

6. Other implant delivery mishaps
affinity between the implant surface &
the bone interface is disturbed.
• Burning bone
• Contamination

ACCORDING TO HUBERTUS SPIEKERMANN et al
Surgical complications
1) Intraoperative complications
2) Postoperative complications
Immediate complications
Late complications

Immediate post-operative Complications
Any of the following may occur , or even in combination:
Hemorrhage
Hematoma
Edema
Early infection
Wound margin separation
Mucosal perforations
Surgical emphysema
Implant mobility

1. Haemorrhage & hematoma
Expansion haematoma
Treatment

2
2. Edema
Cause
Treatment

3. Early Infection
Cause
Characterized by
Treatment

4. Wound margin dehiscence – mucosal
perforation
Cause
Treatment

5. Surgical emphysema
Cause
Symptoms
Treatment

6.Implant mobility
Rotational
Horizontalvertical

Possible causes of fixture mobility
( Adell ,et al 1981;Branemark , et al 1983)
During the 1st stage surgery , the tissue bed of the
fixture site is damaged by aggressive thermal changes
during drilling or tapping procedures causing fracture
to the bony threads in the site.
 Extension of the acute inflammation to the fixture site
due to exposure of the surgical site during healing period.
Occlusal or traumatic forces transmitted to the fixture
prior to adequate bone healing .
Under excessive fixture loading conditions , bony threads
fracture in the fixture site .
Radiation dosages above 1500 Rads causes damage

Clinical implant mobility scale
0 Absence of clinical mobility with 500g in any
direction
1 Slight detectable horizontal movement
2 Moderate visible horizontal mobility upto
0.5mm
3 Severe horizontal movement greater than
0.5mm
4 Visible moderate to severe horizontal and any
vertical movement

Good
morning

Implant failure
complications
and
maintenance

8
Late postoperative complications :
•Implant fracture
•Chronic sinusitis
•Chronic pain
•Mucosal irritation
•Peri- implant pathology
•Implant mobility

1. Implant fracture
overload
Non-
passive
Design
mat.

2
Management

2.
2. Chronic pain:
occur –inflammed tissue
sinusitis ,
oro- antral fistula ,
nerve damage etc… ( Ehrenfeld et al 1990).
body #,
bone stressed
• If the implant in the mandible is placed too close to the
mandibular canal …….. Such patients may experience pain
when the implants are loaded or even force is exerted on it.
• In very advanced stages of peri-implantitis , the inferior
alveolar nerve may also become affected
Treatment

2
3. Permanent mucosal irritations
interforaminal region

Treatment
Alter the shape of the prosthesis
If this is ineffective , surgical lowering of the floor of the
mouth or implant removal may be the last resort

4. Peri- implant pathology
Periodontic complication
Pathologic alterations in the tissues that contact a dental
implant fall under the definition of PERI-IMPLANT PATHOLOGY
.
The development of an inflammatory process that is limited
to the peri-implant soft tissues can be defined as PERI-IMPLANT
MUCOSITIS.

European federation of periodontology defined PERI-
IMPLANTITIS as progressive peri-implant bone loss
accompanied by inflammatory pathology in the soft tissues
.

ETIOLOGIC FACTORS
Newmann & Flemming 1988, 1992; Rosenberg et al 1991;
Quirynen et al 1992)
Bacterial
(plaque
theory)
Bio- mechanical
overload

Biomechanical overload
bio-mechanical overload
microfractures
crestal bone loss
loss of osseointegration
apical migration

2
Bacterial infections
• primarily plaque-induced.
• inflammation are generally associated with Gram + positive
aerobic cocci & non –motile rods.
•If plaque accumulates on the implant surface, epithelium
appears ulcerated and loosely adherent.
• In addition, the implant lesions extend into the supracrestal
connective tissue and approximate/populate the bone marrow

ADDITIONAL POSSIBLE ETIOLOGIC AND MODIFYING
FACTORS
Implant surf. &
shape
Peri-implant
mucosa
Co-
factors

CLASSIFICATION OF PERI-IMPLANTITIS
Peri-implantitis - Class 1
Slight horizontal bone loss with minimal peri-implant defects
Treatment :
Initial treatment is targeted toward elimination of etiologic
factors .
Surgical therapy:
• cleaning the implant surface ,
• revising the osseous topography .
• Pocket elimination via apical repositioning of the soft tissues
• adjunctive antibiotic treatment if indicated

Peri-implantitis - class 2
Moderate horizontal bone loss with isolated vertical defects.
Treatment
-Initial therapy
Surgical therapy
Cleaning the implant surface
osseous recontouring , pocket
elimination via apical repositioning of soft tissues ,
adjunctive treatment using systemic medications
e.g. tetracycline or metronidazole.

Peri-implantitis- class 3
Moderate to advanced horizontal bone loss with broad,
circular bony defects.
Treatment
Initial cause related therapy
Surgical therapy- implantoplasty
Cleaning of the implant
surface , pocket elimination
via apical repositioning of the
soft tissues or by osseous
regeneration techniques ;
adjunctive antibiotic treatment

8
Peri-implantitis -class 4
Advanced horizontal bone loss with broad, circumferential
vertical defects, as well as loss of the oral and/or vestibular
bony wall.
Treatment
Initial cause related therapy
Surgical therapy
Cleaning of the implant
surface , pocket elimination
via bone reneration techniques
possibly using autologous bone
transplants ; adjunctive antibiotic
therapy.

Veneer fracture
Non-passive fit
Loosening & fracture of the prosthetic insert
Loosening & fracture of occlusal screws
Framework fracture
Esthetic complications
Functional complications

1 . Veneer fracture
- insufficient support from framework
- Poor alloy surf. Preparation
- deformation under occlusal load

2. No passive fit
• Long -term success of a multiple implant restoration

Factors that impair achievement of passive fit
Dim . Changes Impression tec.

2
3. Loosening & fracture of occlusal screws
- Patrick ,Stevens
Screw design
Inadq. torque
cantilever
Occlusion

1. Screw design
conical screw has a inclined plane
Flat head screw has straight plane giving more
equal distribution of force

2
2.Cantilever extension
Recommended cantilever
x 2.5 x

2
-Non-ideal cantilever: long distal cantilever demonstrating
bone loss and poor support.
- cause load magnification and overloading of the implant next
to the cantilever extension, which in turn leads to bone loss
Excessive Cantilever

2
- With occlusal forces acting on the cantilever, the implant
becomes a fulcrum and is subjected to axial, rotational forces
- The weakest link in the cantilever design is the location and
size of the pontic and the intensity of occluding masticatory
forces. These forces tend to be greatest in distally located
pontic cantilevers. A mesial cantilever is favoured over a distal
cantilever for this reason

3. Inadequate torque application
Preload - Preload is the clamping force on a screwed joint
produced by tension in the screw as a result of it being
tightened
Amount of torque suggested the
manufacturers on the abutment screw range
from 20 to 35 N/cm and a torque wrench is
required to obtain a more consistent value

8
4. Occlusal discrepancy and jaw relation
-occ. Scheme
-Parafunction

2
Management
- Prosthetic screw -removed with a counter-clockwise rotation
Amount of torque suggested the
manufacturers on the abutment screw range
from 20 to 35 N/cm and a torque wrench is
required to obtain a more consistent value

2
4. Loosening & fracture of the prosthetic insert
-Overload
-Improper angulation
-Metal fatigue
Management Abutment # - THREADED
-CEMENTED
- Retrieval kits

8
5. Framework fracture
Cause ….

6. Esthetic complications
• primarily a problem in the anterior maxilla
There are several types of esthetic risk factors :
Gingival Risk Factor
Dental Risk Factor
Bone Risk Factor
Patient risk factor

7. Functional complications
-implant borne superstructures.
-Phonetics

Prosthodontic considerations in implant
failure
Force delivery
Tooth implant connection
Single implant restoration

1. Force delivery and failure mechanisms
The moment of force about a point tends to produce
rotation or bending about the point.
Moment loads (torque or torsional loads):
Defined as a vector (M),the magnitude of which equals the
product of force magnitude multiplied by the perpendicular
distance from the point of interest to the line of action of force.

•
•
Occlusoapical
Faciolingual
Mesiodistal

Clinical Moment Arms
Cantilever length moment arm
Occlusal height moment arm
Occlusal width moment arm
.

2. Tooth implant connection

•Rangert –
•Prosthesis movement – 12-97 microns
•Abt. – prosthetic screw - 10- 60 microns
•Biomechanical risk is reduced

GUIDELINES
1. Tooth mobility
2. Anterior teeth should not be connected

3. Single implant restoration
•The replacement of single molars with implant has provided
more problems than originally anticipated.
•The occlusal table of a normal sized molar is relatively large
compared with a standard sized implant (3.75-4)
•The potential for bending is tremendous because a cantilever
in all 360°actually exists. In order to reduce the bending a
wider and stronger support system had to be designed.
•These feature combined with a narrower buccolingual
dimension for the restoration ,dramatically reduces the potential
for bending

Risk factors

Risk factors
General
Esthetic
Bio-mechanical

Age
General
health
Pt. Psychology
Eitiogy
edentulism
GENERAL risk factor

OK CAUTION DANGER
-Old infarcts - angina - recent infarcts
- CHD - valvulopathies
- diabetes - AIDS
- renal insuf. - haemophilia
2. GENERAL HEALTH

8
Osteoporosis:
Significance
• More common in women
•Greater loss of trabecular
bone than cortical bone
•Difficult to achieve
immediate stability

2
Prevention
•Treatment for osteoporosis(Hormone Replacement
Therapy , dietary calcium, weight bearing exercise)
•Use of hydroxyapatite coated implants to provide a
biomechanical bonding rather than a mechanical one
•Increase no.. of implants to distribute load
•Increase healing period

Diabetes
Significance
•Liability of infection due to
fragility of vessels so as to alter
blood supply
•Impaired wound healing
•Surgical stress can release
endogenous norepinephrine

Prevention
•Screen patients for diabetes
•If patient is diabetic get medical consultation
•If uncontrolled, treatment postponed till condition is
under control
•Preoperative antibiotic prophylaxis, aseptic technique,
atraumatic tissue handling and frequent and close follow
up

Smoking
NICOTINE AND ACRYL-HYDROCARBONS –
Depress osteoblastic activity ,reduces collagen
synthesis ,inhibits osteosynthesis .
Also causes local vasocontriction
CARBON MONOXIDE
Forms carboxyhemoglobin
HYDROGEN CYANIDE
Inhibits cellular respiratory
enzymes
Tissue hypoxia & altered
tissue healing

Significance
Smoking cessation 2weeks before and 3 weeks after surgery

3. PATIENTS PSYCHOLOGY
4. EITIOLOGY OF EDENTULISM

Esthetic risk factor

Gigival risk factor
1. Smile line
2. Gingiva
3. Interdental papilla

Dental risk factor
1. Form of natural teeth
2. Interdental contact

Bone risk factor
1. Vestibular concavity
2. Adjacent implants
3. Vertical bone resorption

Patient risk factor
1. Esthetic requirement
2. Hygiene level

BIOMECHANICAL RISK FACTOR
GEOMETRIC RISK
FACTOR
OCCLUSAL RISK
FACTOR
BONE &IMPLANT
RISK FACTOR
TECHNOLOGICAL
RISK FACTOR

1. Geometric load factors
• bending overload
• Geometric load factors that can compromise the support
and result in increased overload include:
 Fewer than three implants
 Implants connected to teeth
 Implant in a line
 Cantilever extensions
 Occlusal plane beyond the implant support eg. buccal and
lingual cantilevering
 Excessive crown implant ratio

Smaller
2. Occlusal risk factor
Bruxism, parafunction , natural tooth
fracture
-Lateral occlusal contacts on implant supported
prosthesis

2
3. Bone &implant risk factor
-Primary stability
-
- smaller implant dia.

4. Technological risk factor
- lack of prosthetic fit
-Cemented prosthesis

Alarm signals
Prosthetic Screw loosening # of veenering mat.
# abutment screw bone resorption

Implant Maintenance

GOALS
- PLAQUE
NEGATE
EARLY
MICROBES
ELIMINATE
EXISTING
PLAQUE
ALTER
EXISTING
PLAQUE

DIAGNOSTIC PROCESS
BLEEDING ON PROBING
SUPPURATION

YRADIOGRAPHIC BONE
LOSS
PROBING DEPTH
IMPLANT MOBILITY

Clinically stable implant
-Absence of bleeding
-Absence of suppuration
-PD 3mm
-Min. bone loss
-Immobile

CUMULATIVE INTERCEPTIVE SUPPORTIVE THERAPY
Lindhe
Protocol A, B, C, D

MECHANICAL DEBRIDMENT : CIST PROTOCOL A
1. Plaque & calculus
2. BOP +
3. Sup. −
4. PD 4mm
1. Carbon fibre/
plastic currettes
2. Rubber cups

ANTISEPTIC THERAPY : CIST PROTOCOL A+B
1. Plaque & calculus
2. BOP +
3. Sup. + / −
4. PD 4- 5mm
1. Mech. Deb.
2. 0.2 % Chx
gluconate

ANTIBIOTIC THERAPY : CIST PROTOCOL A+B+C
1. BOP +
2. Sup. +/ −
3. PD 6mm
4. radiographic bone
loss
1. Mec . Deb.
2. Antiseptic therapy
3. Antibiotic therapy

ANTIBIOTIC
LDDSYSTEMIC
ACTISITE

REGENERATIVE or RESECTIVE THERAPY : CIST PROTOCOL
A+B+C+D
1. BOP –
2. Sup . –
3. PD - reduced
1. Mec . Deb .
2. Antiseptic
3. Antibiotic
4. Barrier memb. & grafts

IMPLANT QUALITY SCALE
Misch
GROUP I – SUCCESS (Optimum health)
1. No pain
2. 0 mobility
3. <2mm
radiographic
b. loss
4. PD <5mm
5. No exudate
Normal
management

GROUP II SURVIVAL ( Satisfactory health)
1 . No pain
2. 0 mobility
3. 2-4mm
radiographic b.
loss
4. PD 5-7mm
5. No exudate
1. Reduction of
stresses
2. Shorter time
b/w recalls
3. Gingivoplasty
4. Yearly
radiographs

GROUP III – SURVIVAL ( Compromised health )
1. Reduction of
stresses
2. Drug therapy
3. Surgical reentry
4. Change
prosthesis
/implant
1. No pain
2. 0 mobility
3. Radiographic b
loss> 4mm
4. Pd > 7m
5. May have
exudate

GROUP IV - FAILURE ( Clinical / absolute)
1. Pain
2. Mobility
3. Radiographic b
loss > half
implant
4. Exudate
5. Extruded
REMOVAL OF
IMPLANT

2
HOME CARE

gr
RECALL VISIT
1,2,4,12,24 wks
1. Evaluate prosthesis
2. Radiographic examination
3. mobility

CONCLUSION
Though implants are the preferred modality of treatment for
both completely as well as partial edentulous conditions but
it comes with its own set of complications . Hence a detailed
knowledge of the risk factors and complications is required to
prevent and manage implant failure

E• References
1. Contemporary implant dentistry – C. Misch- 3rd edition
2. Risk factors in implant dentistry – Renouard , Rangert
3. Art & Science of dental implants – Babbush
4. Atlas of oral implantology – Cranin
5. Clinical periodontology & implant dentistry - Lindhe
6. Implant prosthodontics – Patick , Stevens
7. Oral implantology - Kakar
8. BDJ 2007, 202 pg 123
9. Dental update 2002: 29 pg 456
10. J Can Dent Assoc 2002;68: 103
11. Eur J Oral Sci 1998 ;106: 721

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