dental implant complications
DESCRIPTION
implants, complications, failures, periimplantitis, management of implant complicationsTRANSCRIPT
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
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