should differentiate between two concepts: accidents and complications (Annibali et al,
as in the case of implantology procedures, without the interruption of medication and as long as values concerning
are factors that trigger the occurrence of edemas and patient’s susceptibility.
using non-excessive tension and bone-supported retriever
Use of a, and
Before the suspicion that the inflammation could compress any nervous structure, are crucial to minimize the risk of lesions (Misch & Resnik, 2010).
A flow diagram of airway management and control of massive hemorrhage in the floor of mouth associated with implant placement in the anterior mandibular region (Kalpidis & Setayesh, 2004).
Mylohyoid artery branch of ia artery as it enters the mandibular foramen
inhibit axon sprouting centrally and ectopic discharges from injured axons-
(Park & Wang, 2005) and formation of sequestration of bone debris
because the granulation tissue that forms will promote healing by secondary intention. Use of ct grafts guaranteeing the closure of the wound and the enlargement of the mucosa thickness around implants,
sharper angles observed at the inner walls of the sinus in the vicinity of the second upper bicuspid presents a higher risk of perforation
when bone volume is inadequate to support an implant with sufficient length,
orthopedic revisions, craniofacial defects, or post oral cancer ablation associated with surgery/radiation.
by correcting crown-root proportion, contour of soft tissues and the relation with neighboring teeth. (based on the osteogenic distraction of a bone fragment containing the integrated implant)
that can increase the availiable bone length by 50
worth mentioning a case report describing the migration of a zygomatic implant to the cranial fossa. This is a major complication that can end up with a cerebral lesion or an infection that must be prevented with a preoperative and postoperative three-dimensional radiographic study (Reychler & Olszewski, 2010).
1.5 to 2 mm of bone should be present between an implant and the adjacent tooth. Malpositioned implant- adjacent teeth non vital- endodontic procedure
provide enough blood for the healing process derived from an implant placement (Chrcanovic & Custodio, 2009). The bone in this area is usually sclerotic and undergoes severe resorption as a consequence of a large period of edentulism
More than 80% of factures are located in the molar and premolar regions. specially cantilevers in fixed prostheses, occlusal overload or/ and parafunctional habits
Dental implant complications
• Implantology is an ever growing field.
• Nevertheless, it has, as every surgical
procedure, several complications that can
occur and that must be known in order to
prevent or solve them.
• It is mandatory to classify all those clinical
complications that can arise.
• Accidents are events that occur during surgery
Accidents always happen during surgical procedures.
• Complications appear lately, once surgery is already
performed. There are two kinds of complications,
depending on the time they emerge: early and late.
Early-stage complications appear in the immediate
postoperative period and interfere with healing,
Late-stage complications arise during the process of
• Failures occur when the professional and/or
the patient do not obtain the desirable
• Iatrogenic acts are regarded as accidents,
complications or failures caused by a
deficient praxis of the professional
(Annibali et al, 2009)
Local complications in dental
• Ecchymoses and haematomas
• Flap dehiscence
• Sensory disorders
• Perforation of the mucoperiosteum
• Maxillary sinusitis
• Mandibular fractures
• Failed osseointegration
• Bony defects
• Periapical implant lesion
(Misch and Wang,2008)
• Surgical complications
• Biologic complications
• Technical or mechanical
• Esthetic and phonetic complications
• Hemorrhage and hematoma
• Neurosensory disturbances
• Damage to adjacent teeth
• Dehiscence and recession
• Periimplantitis and bone loss
• Implant loss or failure
• Screw loosening and fracture
• Implant fracture
• Fracture of restorative
• Esthetic complications
• Phonetic complications
• Common accident as a consequence of local-anatomical
or systemic causes.
Causes of bleeding:
lesions in any sublingual, lingual, perimandibular,
or submaxillary artery
Surgeries in the lower and anterior area of totally
edentulous patients who have a deficit in the quality and
quantity of bone.
• More prone patients fall in the following category:
Group 2 of medical-systemic risk:
Irradiated patients (radiotherapy),
Patients with coagulation disorders (anticoagulated
patients or those with haemostatic disorders)
(Buser et al., 2000)
• Group I includes high risk patients:
Patients with serious systemic diseases (rheumatoid
arthritis, osteomalacia, imperfect osteogenesis),
Immunodepressed (HIV, immunosupresory
Drug addicts (alcohol, etc.),
Unreliable patients (mental or psychological
• Elderly - probability of comorbidity is higher and
mandatory to know their medical history.
Therapeutic options in these patients comprise two
Decrease or eliminate the anticoagulant therapy once
patient and physician have assessed risks and benefits.
Invasive treatments can be performed ( Bacci et
International Normalized Ratio (INR) are > 4, and
Adequate hemostatic measures are followed and,
Use atraumatic surgery techniques;
Treatment: local intraoperative or postoperative
Local hemostasis (suture, compression, the use of
hemostatic microfibrilar collagen gauzes, oxidized
cellulose, reabsorbable fibrin, or mouth rinsing with
4,8% of tranexamic acid)
Precautions to be taken:
Strongly recommended to carry out an
exhaustive tomography study of the anatomy of
mandible and maxilla.
• Swelling - more noticeable 24 hours
after performing surgery
Bone regenerating techniques, and
• Leads to trismus, lack of hygiene in the
wound and discomfort to the patient.
• Decreases with time, and can easily
vanish after a few days.
• Severe bleeding and the formation of massive
hematomas in the floor of the mouth are the result
of an arterial trauma.
Several types of hemorrhagic patches can develop as a
result of injury:
Petechiae (<2 mm in diameter),
Purpura (2 to 10 mm), and
Ecchymosis (>10 mm).
Ecchymosis are the result of an intermental
A schematic representation of the arterial anatomy in
the floor of the mouth (Kalpidis
& Setayesh, 2004).
Swelling and elevation of floor of the mouth
Increase in tongue size
Difficulty in swallowing or speech
Pulsating or profuse bleeding from the floor of the
mouth or the osteotomy site
Bleeding site during
Posterior mandible Mylohyoid Finger pressure at the site
Middle lingual of
Submental Surgical ligation of facial
Anterior lingual of
Terminal branch of
sublingual or submental
cauterization, or ligation
Invading the mandibular
Inferior alveolar artery Bone graft
Treatment of a hemorrhage at an implant osteotomy site (Park & Wang,
• The blood supply of the maxillary sinus is derived
from the infraorbital artery, the greater palatine
artery and the posterior superior alveolar artery
(Chanavaz, 1990; Uchida et al., 1998a).
• Bleeding during sinus augmentation is rare because
the main arteries are not within the surgical area.
• Rare complication, though it can lead to severe
consequences (McKenzie & Rosenberg, 2009).
Inadvertent insufflation propulsion of air into tissues
under skin or mucous membranes,
Air from a high-speed handpiece, air/water syringe, an
air polishing unit or an air abrasive device can be
projected into a sulcus, surgical wound, or a laceration in
(Liebenberg & Crawford, 1997)
• Nerve lesions are both an intraoperative accident and
a postoperative complication that can affect the
infra-orbital nerve, the inferior alveolar nerve, or its
mental branch and the lingual nerve.
• These complications have a low incidence (reported
(Misch & Resnik, 2010)
Several implants in contact to the Inferior
Alveolar nerve in patients with postoperative
Postsurgical intra-alveolar edema or hematomas- produce
a temporary pressure increase, especially inside the
Compression, stretch, cut, overheating, and accidental
(Annibali et al., 2009)
• Poor flap design,
• Traumatic flap reflection,
• Accidental intraneural injection,
• Traction on the mental nerve in an elevated
• Penetration of the osteotomy preparation
• Compression of the implant body into the
(Misch & Wang, 2008).
The nerve injury may cause one of the following
• Parasthesia (numb feeling),
• Hypoesthesia (reduced feeling), hyperesthesia
• Dysthesia (painful sensation), or
• Anesthesia (complete loss of feeling) of the teeth,
the lower lip, or the surrounding skin and mucosa
(Greenstein & Tarnow, 2006 as cited in Sharawy &
• Neurapraxia: there is no loss of continuity of the
nerve; it has been stretched or undergone blunt
the parasthesia will subside, and feeling will return in
days to weeks.
• Axonotmesis: nerve damaged but not severed; feeling
returns within 2 to 6 months.
• Neurotmesis: severed nerve; poor prognosis for
resolution of parasthesia.
Sharp needle test( tingle or painful)
Shortest test between indentation
Blunt cotton swab
test( tingle or
Pulp testing teeth
Mapping area of
Recommendations to avoid nerve injuries
during implant placement (Worthington,2004)
Be sure to include nerve injury as an
item in the informed consent
Measure the radiograph with care.
Apply the correct magnification
Consider the bony crestal anatomy:
Is the buccolingual position of the
crestal peak of bone influencing the
measurement of available bone?
Consider the buccolingual position of
the nerve canal.
Use coronal true-size tomograms
Allow a 1 to 2 mm safety zone.
Use a drill guard.
Take care with countersinking not to
lose support of the crestal cortical
Keep the radiograph and the
calculation in the patient’s chart as
powerful evidence of meticulous patient
Treatment (Misch & Resnik, 2010).
• Too much proximity between the implant and a nerve-
removal as soon as possible
• Treatment with corticosteroids and non-steroidal anti-
inflammatory drugs - to control inflammatory
reactions that provoke nervous compression.
• Topical application of dexamethasone (4 mg/ml) for 1
or 2 minutes enhances recovery,
• Oral administration (high doses)- within one week of
injury- prevention of neuroma formation
• Remove offending element
• Recovery on 1 to 4 weeks
• Remove offending element
• Recovery on 1 to 3 months
• Complete anesthesia for more than 3
• May have triggering signs or increase in
sensation to sharp stimuli
• Intraoperative nerve section - microsurgery
techniques to reestablish nerve continuity.
• Neurosensorial loss - checked at different
moments to determine with precision the
evolution of the lesion
• Resort to microsurgery if, after four months -
patient’s situation has not improved, pain
persists and there is a remarkable loss of
Aspiration and swallowing of
Images of a screw driver in the digestive tract. (b)
Screw driver into pulmonary tissue.
• Vital emergency if the instrument has entered the
• Recommended to tie all tiny and slippery instruments
with silk ligatures or else use a rubber dam
(Bergermann et al., 1992).
• Gastroscopy or colonoscopy with a proper medical
follow-up required to locate.
Flap dehiscence and exposure of
graft material or barrier membrane
• The most common postoperative complication is wound
dehiscence, which sometimes occurs during the first
10 days (Greenstein et al., 2008).
Wound dehiscence at one week post surgery in a
diabetic patient with oral candidiasis
• Flap tension,
• Continuous mechanical trauma or irritation associated
with the loosening of the cover screw,
• Incorrect incisions
• Poor-quality mucosa (thin biotype, traumatized),
• Heavy smokers, patients treated with
corticosteroids, diabetics, or irradiated patients
(Lee & Thiele, 2010)
(Speroni et al., 2010; Stimmelmayr et al., 2010).
•No surgical correctionSmall
Free connective tissue grafts - - allows better esthetical
results , maintenance of periimplant health
1) Careful preoperative assessment of the soft tissues
to measure the amount of keratinized mucosa
present and planning of augmentation procedures as
2) Minimally invasive flap elevation and reflection with
careful removal of any bone débris beneath;
3) Proper suturing;
4) Sensible temporization, rebasing and relining; and
5) Delaying the use of removable dentures until two
weeks after surgery.
maxillary sinus lift
• The Schneiderian membrane- characterized by
periosteum overlaid with a thin layer of pseudociliated
stratified respiratory epithelium,
• Constitutes an important barrier for the protection
and defense of the sinus cavity.
Schneiderian membrane perforation occurs in
10% to 60% of all procedures
Anatomical variations such as a maxillary sinus septum,
spine, or sharp edge are present
Very thin or thick maxillary sinus walls
Angulation between the medial and lateral walls of the
maxillary sinus seemed to exert an especially large
influence on the incidence of membrane perforation.
• folding the membrane up against
itself as the membrane is
to 8 mm)
• do not lend themselves to
closure by infolding
• Repaired with collagen or a
Loss of the implant or graft
materials into the maxillary sinus
Changes in intrasinal and nasal pressures;
Autoimmune reaction to the implant, causing
peri-implant bone destruction and compromising
Resorption produced by an incorrect
distribution of occlusal forces
(Galindo et al., 2005)
Immediately retrieved surgically via an intraoral
approach or endoscopically via the transnasal route
to avoid inflammatory complications
a bone reconstruction procedure of the maxilla
should be performed.
Malposition or angulation of an
• The definition of a ‘malpositioned implant’ is an implant
placed in a position that created restorative and
biomechanical challenges for an optimal result.
most common - deficiency of the osseous housing around
the proposed implant site.
Bone resorption :
osseous remodeling following tooth loss,
Use of repositioning system.
Improves esthetic effects, the biomechanical
behavior of the implant
• Assess the characteristics of the edentulous
zone subject to rehabilitation using clinical
and radiological CT, or cone beam CT imaging
(Dreiseidler et al., 2009)
• Use short or tilted implants (aproximately
• avoid anatomical structures (mental nerve,
(a) Implant installed . (b) Control CT Scan after
displacement and before second stage surgery. (c)
Change of position.
There is an absence or loss of osseointegration and,
Loss of stability
If in the sinus: can be removed a few days later by opening
the lateral wall of the maxillary sinus, or
by endoscopic via through a nasal window.
Accurate surgical technique - using osteotomes to prepare
the implant beds or
a drill with a smaller diameter to that of the fixture, or
using implants with a conical compressive form.
Injury to adjacent teeth
• This problem arises more frequently with single implants
A malpositioned implant hitting an adjacent tooth
• Damage to teeth adjacent to the implant site-
subsequent to the insertion of implants along
an improper axis or after placement of
excessively large implants.
• Risk of a retrograde Periimplantitis- distance
between tooth and implant apexes is shorter
and when the lapse of time between the
endodontic procedure and the implantation is
(Quirynen et al., 2005; Tozum et al., 2006; Zhou et
• Use of a surgical guide, radiographic analysis and CT
scan can help locate the implant placement.
• Inspection of a radiograph with a guide pin at a depth
of 5 mm will facilitate osteotomy angulation
corrections (Greenstein et al., 2008).
• Prevent a latent infection of the implant from the
potential endodontic lesion, endodontic treatment
should be performed
Perforation of the lingual cortical
• Associated with atrophic mandibles
• Central area of the mandible has a greater risk for
Reduction and stabilization of the fracture with
titanium miniplates or resorbable miniplates.
Splinting implants to reduce and immobilize the fracture
Thin mandibular alveolar crests- increase width by
performing bone grafts
Accurate tomography imaging study
• Incidence- 6%
Stress applied to prosthesis
Height or depth of antirotational component
Platform dimensions on which the abutment is seated
• Large diameter implants with large platform
dimensions reduce the forces applied to the
• Decreased preload force
• Increase thread tightening
• Can be associated with exudate and bone loss
Complete exposure of the implant cover screw
Removal of the healing cover
Flushing of the implant with chlorhexidine,
insertion of a permucosal extension
Oral hygiene with soft toothbrush
Chlorhexidine application over the area twice
PME inserted, tissue approximated
Membrane can be used
Antibiotics and chlorhexidine daily rinses
Uncovering of implant, removal of cover screw
Curetting of granulation tissue
Cleaning of implant surface-diamond bur/ air abrasive
Bone grafts and membrane
• Infrequent complication (among 0,2 y- 1.5% of cases )
(Eckert et al., 2000)
• Complications is higher in implants supporting fixed
partial prosthesis than in complete edentulous patients.
Defects in the implant design or materials used in their
A non-passive union between the implant and the
prosthesis or by mechanical overload,
Removal of the implant and its replacement by another one
(a) Implant fractured in maxillary posterior
region. (b) Implants retrieved. (c)
Substitution for a wider diameter in the same
• Peri-implantitis is defined as an inflammatory
process which affects the tissues around an
osseointegrated implant in function, resulting
in the loss of the supporting bone, which is
often associated with bleeding, suppuration,
increased probing depth, mobility and
radiographical bone loss.
• Peri-implant mucositis was defined as
reversible inflammatory changes of the peri-
implant soft tissues without any bone loss
(Albrektsson & Isidor 1994)
In a systematic analysis, 2003
• Incidence of periimplmant mucositis- 8-44%
• Incidence of periimplantitis- 1- 19%
• History of periodontitis
• Poor oral hygiene
• Exposed threads
• Exposed surface coatings (roughened
• Deep pockets (placed too deep, placed into
• No plaque removal access (ridge lap crown,
Risk factors for peri-
Radiological evidence for vertical destruction
of the crestal bone
Saucer shaped defect
Formation of a
Swelling of the
DIAGNOSTIC DIFFERENCES BETWEEN
PERIIMPLANTITIS AND PERIIMPLANT MUCOSITIS
Clinical parameter Peri-implant mucositis Peri-implantitis
Increased probing depth +/- +
BOP + +
Suppuration +/- +
Mobility - +/-
Radiographic bone loss - +
Treatment of peri-implant infection
(adapted from Mombelli & Lang 2004)
No visible plaque,
OHI and local
No loss of bone
when compared to
No BOP, no visible
OHI and local
Loss of bone
OHI and local debridement
Topical antiseptic treatment
Local/ systemic antibiotic
OHI and local debridement
OHI and local debridement
Local antibiotic delivery
Systemic antibiotic delivery
using rubber cups and polishing paster, acrylic scalers
for chipping off calculus.
Effective oral hygiene practices.
Rinses with 0.1% to 0.2% chlorhexidine digluconate for
3 to 4 weeks,
• supplemented by irrigating locally with chlorhexidine
(preferably 0.2% to 0.5%)
Cumulative Interceptive Supportive
Therapy (CIST) modalities (Lang et al, 2004).
1. SYSTEMIC ornidazole (2 x 500 mg/day) or
metronidazole (3 x 250 mg/day) for 10 days
OR combination of metronidazole (500 mg/day) plus
amoxicillin (375 mg/day) for 10 days.
2. LOCAL: application of antibiotics using controlled
release devices for 10 days (25% Tetracycline fibers).
D. Surgical approach:
• using abundant saline rinses at the defect,
• barrier membranes,
• close flap adaptation and
• careful post-surgical monitoring for several months.
• Plaque control is to be assured by applying
• Apical repositioning of the flap following osteoplasty
around the defect.
• Depends on patient s esthetic
expectations and patient related
factors(bone quantity and quality).
• Depends on individual perceptions and
Poor implant placement
Deficiencies in the existing anatomy of the
Crown form, dimension, shape and gingival harmony
is not ideal
Esthetic regions: high esthetic demands, thin
periodontium, lack of hard and soft tissue support
in the anterior esthetic regions
Reconstructive procedures to develop a
natural emergence profile of the implant
Appropriate treatment planning and
• Implant prosthesis with
Unusual palatal contours ( Restricted or narrow palatal
Spaces under and around the superstructure of implant
Mostly observed in severe atrophied maxilla
Management: implant assisted maxillary- overdenture
• Maxillary sinusitis can occur
Contamination of the maxillary sinus with oral
or nasal pathogens or
via ostial obstruction caused by postoperative
swelling of the maxillary mucosa,
Non-vital bony fragments floating freely in
the maxillary sinus.
Lack of asepsis during sinus augmentation
(Timmenga et al., 2001)
Preoperative evaluation of sinus clearance-related
Postsurgery: a nasal decongestant (xylomethazoline
0.05%) and topical corticosteroid (dexamethasone
0.01%) to prevent postsurgery obstruction of the
Perioperative antibiotic prophylaxis (cephradine 1 g
3 times daily, starting 1 hour before surgery and
continued for 48 hours after surgery)
• Osseointegration was originally defined as a
direct structural and functional connection
between ordered living bone and the surface
of a load-carrying implant
(Albrektsson et al. 1994).
Osseointegration between an endosseous
titanium implant and bone can be expected
greater than 85% of the time when an implant is
Implant failure Previous failure
Surface purity and
Intra-oral exposure time
Mechanical overloading Premature loading
Traumatic occlusion due to
Patient(local factors) Oral hygiene
Presence of natural teeth
Periodontal status of natural
Impaction of foreign bodies
(including debris from surgical
procedure) in the
Patient( systemic factors) Vascular integrity
Predisposition to infection, e.g.
age, obesity, steroid therapy,
metabolic disease (diabetes)
Hypersensitivity to implant
Overheating (use of
contamination, e.g. via
saliva, perioral skin,
operating room air or air
expired by patient
Dental implant placement is not free of complications, as
complications may occur at any stage.
Careful analysis via imaging, precise surgical techniques and
an understanding of the anatomy of the surgical area are
essential in preventing complications.
Prompt recognition of a developing problem and proper
management are needed to minimize postoperative