dental implant complications

DENTAL IMPLANT- COMPLICATIONS

Introduction• 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 osseointegration.

• Failures occur when the professional and/or the patient do not obtain the desirable results

• 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 implant surgery.

Early-stage complications

• Infection• Edema• Ecchymoses and haematomas• Emphysema• Bleeding• Flap dehiscence• Sensory disorders

Late complications

• Perforation of the mucoperiosteum• Maxillary sinusitis• Mandibular fractures• Failed osseointegration• Bony defects• Periapical implant lesion

(Misch and Wang,2008)

CLASSIFICATION (Carranza)

• Surgical complications• Biologic complications• Technical or mechanical

complications• Esthetic and phonetic

complications

Surgical

complications

• Hemorrhage and hematoma• Neurosensory disturbances• Damage to adjacent teeth

Biologic

complications

• Inflammation• Dehiscence and recession• Periimplantitis and bone loss• Implant loss or failure

Technical complications

• Screw loosening and fracture• Implant fracture• Fracture of restorative

materials

Esthetic and phonetic complications

• Esthetic complications• Phonetic complications

Bleeding• 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)

Severe smokers

(Buser et al., 2000)

• Group I includes high risk patients:

Patients with serious systemic diseases (rheumatoid arthritis, osteomalacia, imperfect osteogenesis),

Immunodepressed (HIV, immunosupresory treatments),

Drug addicts (alcohol, etc.),

Unreliable patients (mental or psychological disorders).

• Elderly - probability of comorbidity is higher and mandatory to know their medical history.

Therapeutic options in these patients comprise two approaches: Decrease or eliminate the anticoagulant therapy once patient and physician have assessed risks and benefits.

Invasive treatments can be performed ( Bacci et al., 2010):

International Normalized Ratio (INR) are > 4, and

Adequate hemostatic measures are followed and,

Use atraumatic surgery techniques;

Treatment: local intraoperative or postoperative measures 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

• Causes: Wide flaps, Bone regenerating techniques, and surgery time

Edema

• 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.

Management

Careful management

of tissues

Non-steroid anti-

inflammatory drugs

cold pack

corticosteroids

Hemorrhage/ Ecchymosis

• 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 surgery procedure.

A schematic representation of the arterial anatomy in the floor of the mouth (Kalpidis

& Setayesh, 2004).

• Signs or symptoms of life threatening hemorrhage include;

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 duringimplant osteotomy

Arteries Treatments

Posterior mandible Mylohyoid Finger pressure at the site

Middle lingual ofmandible

Submental Surgical ligation of facial and lingualarteries

Anterior lingual ofmandible

Terminal branch ofsublingual or submental

Compression, vasoconstriction,cauterization, or ligation

Invading the mandibularcanal

Inferior alveolar artery Bone graft

Treatment of a hemorrhage at an implant osteotomy site (Park & Wang, 2005)

• 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.

Emphysema• Rare complication, though it can lead to severe

consequences (McKenzie & Rosenberg, 2009).

• CausesInadvertent 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 the mouth (Liebenberg & Crawford, 1997)

Neurosensory disturbances

• 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 between 0%-44%)

(Misch & Resnik, 2010)

Several implants in contact to the Inferior Alveolar nerve in patients with postoperative paresthesia.

Causes

• INDIRECTPostsurgical intra-alveolar edema or hematomas- produce a temporary pressure increase, especially inside the mandibular canal

• DIRECTCompression, stretch, cut, overheating, and accidental puncture(Annibali et al., 2009)

• Poor flap design, • Traumatic flap reflection, • Accidental intraneural injection, • Traction on the mental nerve in an

elevated flap,• Penetration of the osteotomy preparation• Compression of the implant body into the

canal

(Misch & Wang, 2008).

The nerve injury may cause one of the following conditions:• Parasthesia (numb feeling),

• Hypoesthesia (reduced feeling), hyperesthesia (increased sensitivity),

• 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 & Misch, 1999).

SEDDON CLASSIFICATION

• Neurapraxia: there is no loss of continuity of the nerve; it has been stretched or undergone blunt trauma;

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.

• SENSORY TESTING

Sharp needle test( tingle or painful)

Shortest test between indentation

Blunt cotton swab test( tingle or

painfulor none)

Pulp testing teeth

Mapping area of altered

feeling

Temperatures test( cold,

warmth)optional

Recommendations to avoid nerve injuries during implant placement (Worthington,2004)

Be sure to include nerve injury as an item in the informed consent document.

Measure the radiograph with care.

Apply the correct magnification factor.Consider the bony crestal anatomy:

Is the buccolingual position of the crestal peak of bone influencing themeasurement of available bone?

Consider the buccolingual position of the nerve canal.

Use coronal true-size tomograms where needed.

Allow a 1 to 2 mm safety zone.Use a drill guard.

Take care with countersinking not to lose support of the crestal cortical bone.

Keep the radiograph and the calculation in the patient’s chart as powerful evidence of meticulous patient care.

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• Corticosteroids• Recovery on 1 to 4 weeks

NEUROPRAXIA

• Remove offending element• Corticosteroids• Recovery on 1 to 3 months

AXONOTMESIS

• Complete anesthesia for more than 3 months

• May have triggering signs or increase in sensation to sharp stimuli

NEUROTMESIS

• 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 sensitivity.

Aspiration and swallowing of instruments

Images of a screw driver in the digestive tract. (b) Screw driver into pulmonary tissue.

• Vital emergency if the instrument has entered the airways.

• 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

Contributing factors of dehiscence and exposure of the graft material or barrier membrane

• 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)

• Treatment

(Speroni et al., 2010; Stimmelmayr et al., 2010).

•No surgical correction Small dehiscence-

• ResuturingLarge dehiscence

Free connective tissue grafts - - allows better esthetical results , maintenance of periimplant health

• Dehiscences may be prevented :

1) Careful preoperative assessment of the soft tissues to measure the amount of keratinized mucosa present and planning of augmentation procedures as appropriate;

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.

Complications associated with

maxillary sinus lift

SCHNEIDERIAN MEMBRANE PERFORATION

• 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

• Causes:

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.

Management:

• folding the membrane up against itself as the membrane is elevated

Small tears

(<5 to 8 mm)

• do not lend themselves to closure by infolding

• Repaired with collagen or a fibrin adhesive

Larger tears

Loss of the implant or graft materials into the maxillary sinus

Causes:

Changes in intrasinal and nasal pressures;

Autoimmune reaction to the implant, causing peri-implant bone destruction and compromising osseointegration; and

Resorption produced by an incorrect distribution of occlusal forces

(Galindo et al., 2005)

Management:

Immediately retrieved surgically via an intraoral approach or endoscopically via the transnasal route to avoid inflammatory complications

Prevention;a bone reconstruction procedure of the maxilla should be performed.

Malposition or angulation of an implant

• The definition of a ‘malpositioned implant’ is an implant placed in a position that created restorative and biomechanical challenges for an optimal result.

Causes : most common - deficiency of the osseous housing around the proposed implant site.

Bone resorption :osseous remodeling following tooth loss, osteoporosis, etc.

• Treatment:

Use of repositioning system.

Improves esthetic effects, the biomechanical behavior of the implant

Precautions:

• 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 30º) or”

• avoid anatomical structures (mental nerve, maxillary sinus).

Improper implant location/Implant

displacement

(a) Implant installed . (b) Control CT Scan after displacement and before second stage surgery. (c) Change of position.

• Causes:There is an absence or loss of osseointegration and, Loss of stability

Treatment: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.

Precautions: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 also shorter

(Quirynen et al., 2005; Tozum et al., 2006; Zhou et al., 2009).

Precautions:

• 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

Mandibular fracture

Perforation of the lingual cortical during drilling.

Infrequent complication

• Associated with atrophic mandibles• Central area of the mandible has a greater risk for

this complication

• Treatment:Reduction and stabilization of the fracture with titanium miniplates or resorbable miniplates.

Splinting implants to reduce and immobilize the fracture

• Precautions:Thin mandibular alveolar crests- increase width by performing bone grafts Accurate tomography imaging study

Screw loosening

• Incidence- 6%• Causes:Stress applied to prosthesis

Crown height

Cantilever

Height or depth of antirotational component

Platform dimensions on which the abutment is seated

Management and precautions:

• Large diameter implants with large platform dimensions reduce the forces applied to the screw

• Decreased preload force

• Increase thread tightening

IMPLANT EXPOSURE

• Can be associated with exudate and bone loss

• Protocol for partial exposure unassociated with exudate:

Complete exposure of the implant cover screwRemoval of the healing coverFlushing of the implant with chlorhexidine,

insertion of a permucosal extensionOral hygiene with soft toothbrushChlorhexidine application over the area twice

each day

• Implant exposure associated with minimal bone loss

PME inserted, tissue approximated Membrane can be used Antibiotics and chlorhexidine daily rinses

• Implant exposure with exudate and bone loss

Uncovering of implant, removal of cover screw Curetting of granulation tissue Cleaning of implant surface-diamond bur/ air

abrasive Bone grafts and membrane

Implant fracture

• 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.

• Causes:Defects in the implant design or materials used in their construction, A non-passive union between the implant and the prosthesis or by mechanical overload,

Management: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 surgery

INFECTIONS

PERIIMPLANTITIS

PERIIMPLANT MUCOSITIS

HYPERPLASTIC MUCOSITIS

FISTULATIONS

MUCOSAL ABSCESS

Periimplantitis• 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%

Periimplant mucositis

Periimplantitis

• History of periodontitis• Smoking• Poor oral hygiene• Exposed threads• Exposed surface coatings (roughened

surfaces)• Deep pockets (placed too deep, placed

into deficiencies)• No plaque removal access (ridge lap

crown,connected prostheses)

Risk factors for peri-implantitis

Features

Radiological evidence for vertical destruction of the crestal bone

Saucer shaped defect

Bleeding and suppuration on

probingPain

Formation of a peri-implant

pocket

Swelling of the peri-implant tissues and hyperplasia

Diagnosis

• Clinical indices, • peri-implant probing, • bleeding on probing (BOP), • suppuration, • mobility, • peri-implant radiography • microbiology.

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)

Peri-implant pockets 3mm

No visible plaque, No BOP

No therapyneeded

Plaque, BOPOHI and local debridement

Peri-implant pockets >3mm

No loss of bone when compared

to baseline,

No BOP, no visible plaque

Plaque+/_ BOP

No therapyneeded

OHI and local

debridementSurgical resection

Loss of bone when

compared tobaseline

mild

moderate

OHI and local debridementTopical antiseptic treatment

Local/ systemic antibiotic delivery

Open debridement

severe

OHI and local debridement Local/systemic antibiotic

deliveryOpen debridement

Explantation

OHI and local debridement

Surgical resectionTopical antiseptic

treatmentLocal antibiotic delivery

Systemic antibiotic delivery

• A. Mechanical cleansing using rubber cups and polishing paster, acrylic scalers for chipping off calculus. Effective oral hygiene practices.

• B. Antiseptic therapy 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).

C. Antibiotic therapy:

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:

1. REGENERATIVE SURGERY • 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

chlorhexidine gels.

2. RESECTIVE SURGERY• Apical repositioning of the flap following

osteoplasty around the defect.

Esthetic complications

• Depends on patient s esthetic expectations and patient related factors(bone quantity and quality).

• Depends on individual perceptions and desires

• Esthetic complications result from:

Poor implant placement

Deficiencies in the existing anatomy of the edentulous sites

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

• Management:Reconstructive procedures to develop a natural emergence profile of the implant crown

Appropriate treatment planning and implementation

Phonetic complications• Implant prosthesis with

Unusual palatal contours ( Restricted or narrow palatal space)Spaces under and around the superstructure of implant

Mostly observed in severe atrophied maxilla

Management: implant assisted maxillary- overdenture

Postoperative maxillary sinusitis

• 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

• General guidelines for the prevention of transient and chronic maxillary sinusitis after maxillary sinus augmentation (Timmenga et al., 2001)

Preoperative evaluation of sinus clearance-related factors

Postsurgery: a nasal decongestant (xylomethazoline 0.05%) and topical corticosteroid (dexamethasone 0.01%) to prevent postsurgery obstruction of the ostium

Perioperative antibiotic prophylaxis (cephradine 1 g 3 times daily, starting 1 hour before surgery and continued for 48 hours after surgery)

Failed osseointegration

• 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 placed.

Factors Comments

Implant failure Previous failureSurface roughnessSurface purity and sterilityFit discrepanciesIntra-oral exposure time

Mechanical overloading Premature loadingTraumatic occlusion due to inadequaterestorations

Patient(local factors) Oral hygiene

Gingivitis

Bone quantity/quality

Adjacent infection/inflammation

Presence of natural teeth

Periodontal status of natural teeth

Impaction of foreign bodies (including debris from surgical procedure) in theimplant pocket

Soft tissue viability

Patient( systemic factors) Vascular integritySmokingAlcoholismPredisposition to infection, e.g. age, obesity, steroid therapy, malnutrition,metabolic disease (diabetes)Systemic illnessChemotherapy/radiotherapyHypersensitivity to implantcomponents

Surgical technique/environment

Surgical trauma

Overheating (use of handpiece)

Perioperative bacterialcontamination, e.g. via saliva, perioral skin, instruments, gloves, operating room air or air expired by patient

ConclusionDental 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 complications.

Thank you