complications in dental implant surgery

lecture given 9/1/2026

what are the spectrum of implant problems?

diagnosis, assessment, imaging, and treatment planning

issues brought upon by surgical procedures

prosthodontic and/or restorative problems

periodontal or maintenance challenges

medico-legal considerations

what are the reasons for complications?

huge upsurge in number of implants being placed

no more restriction to just specialist

new availability of training courses

poor treatment planning

implants being provided in compromised pts and sites

flawed success rates causing lack of scientific understanding

not adhering to guidelines and standard of care

inadequate communication (pt-dentist-lab-vendor)

complication

it is anything happening with your pt that should not have happened- any adverse event

includes any deviation from what we know, based on our collective experience, to be the expected, uneventful intra- and postoperative course

anything that ‘goes wrong’ is a complication

grade 1 complication

any deviation from the normal postoperative course that does not require pharamacologic intervention (pain, swelling)

grade 2 complication

any deviation from the normal postoperative course that does require pharmacologic intervention (infection)

grade 3 complication

any deviation that requires surgical intervention (incision and draining)

grade 4 complication

life-threatenings complication requiring hospitalization (sublingual hematoma)

minor complication

self-limiting and usually short duration, with no permanent or lasting deficits (swelling and bruising)

major complication

more serious complication that is longer lasting, potentially permanent, with associated possible morbidities (infection, nerve impairment)

avoidable complication

such as a nerve impairment caused by placing an implant in the mandibular canal, without the use of a CBCT scan to give the clinician an accurate representation of the proper nerve location

unavoidable complication

these cannot be avoided or preventable in most instances and is not due to negligence of the implant clinician

reversible complication

usually resolve on their own and have no associated long term morbidity (improper angulation upon implant placement after the first drill osteotomy, which may be corrected easily)

irreversible complication

permanent and cannot be reversed, thus having increased severity and consequences (mandibular fracture after implant placement)

immediate surgical complications of implant placement

poor stability

implant exposure

wrong position

implant fracture

nerve injury

oro-antral communication

bleeding

displacement

late surgical complications of implant placement

flap necrosis

peri-implantitis

loss of graft

donor/graft site infection

bleeding

minor is common, major is uncommon

for pts taking warfarin, the overall frequency of persistent bleeding is ____ (__%) when all dental procedures are considered

HOWEVER
when extractions are combined with placement of an implant, the incidence of persistent bleeding increases to ___%

low, 2

4.8

the mechanism of action of newer medications is different from that of warfarin: they directly inhibit either thrombin (____) or factor Xa (______)

dibigatran

apixaban or riviaroxaban

t/f oral antithrombotic medication, including dual antiplatelet therapy, should be interrupted for simple dental procedures

false- should NOT

in cases of life-threatening hemorrhage after implant surgery, where did most of the implant placements occur?

the region between canines

what is the cause of bleeding during implant placement in the anterior mandible?

perforation of lingual cortex, resulting in injury to the terminal branch of the sublingual or submental artery

retraction of the artery after laceration makes ligation difficult or impossible requiring extraoral surgical approaches

moderate or severe maxillary bleeding my result from injury to…

intraosseous vessels lying within the walls

what is the criteria for infection?

presence of purulent drainage (either spontaneously or by incision) or fistula in the operative region

pain or tenderness

localized swelling

redness, or fever

infection

most early infections occur when grafts are used

bacterial contamination during implant insertion

fungal infections and actinomycotic infections have also been reported

no standard protocol exists regarding prophy or post op antibiotics

problems with immediate implant placement

healing of extraction sites when no socket preservation techniques are used results in the resorption of an average of 1-2mm of vertical alveolar bone height and an average of 4-5mm of horizontal alveolar bone width

2/3 of the bone loss during the first 3 mo after tooth extraction

what are the 3 main sources of blood supply to the alveolar bone around teeth?

periodontal ligament blood vessels

periosteal blood vessels

alveolar bone blood vessels

bone grafting is frequently used to prevent ______ and to minimize ___________

collapse, minimize resorption of the thin buccal plate

what are the suggested survival rates of immediate implants?

97.3% to 99%

what are the benefits of immediate placement implants?

dimensions of the alveolar ridge can be maintained

soft tissue preservation is optimal

the number of operative interventions required and the treatment time is reduced

ideal orientation of the implant may be achieved

eventually may provide optimal restorative esthetics

what are the disadvantages of immediate placement implants?

surgically demanding, complex procedure

risk of marginal mucosal recession

adjunct connective tissue graft

adjunct bone graft or guided bone regeneration

what are indications for immediate placement implants?

good oral hygiene

presence of a single failing tooth with good adjacent dentition

presence of adequate and harmonious gingival architecture

adequate bone volume with minimum dimensions of 3.5-10mm and without the need for bone grafting

no dental trauma affecting the alveolar bone

what are contraindications for immediate placement implants?

active infection

lack of bone beyond the apex

a close relationship to anatomic vital structures

dental history of bruxism

parafunctional habits

lack of stable posterior occlusion

perforation or loss of the labial bony plate after tooth removal

inability to achieve primary stability

horizontal bone defect

the longest distance in a perpendicular direction from the implant surface to the socket wall

jumping distance

the horizontal distance between the implant surface and the surrounding bony wall of the socket

human and animal studies have shown that, in implant sites with a horizontal defect dimension of ___mm or less, spontaneous bone regeneration and osseointegration with adequate bone-to-implant contact can occur

however

if the horizontal defect dimension is larger than ___mm, the use of a barrier membrane with or without membrane supporting bone grafting material is warrented

2

2

what are possible reasons for fenestration/implant exposure?

thing cortical plate

un-even crestal ridge

too large implant

what can lead to poor inital stability of an implant?

bone quality and quantity

implant site (anatomic position)

implant diameter

implant length

surgical technique

what can be part of improper surgical technique?

over size drilling

under length drilling

perforating cortical plate

changing implant drilling direction

wrong implant drilling system

do undersized drilling, osteotome technique, or flapless enhance primary stability?

there is weak evidence that they can ehnance primary stability

iatrogenic nerve damage

can result in partial or complete paresthesia, analgesia, anesthesia, or in rare cases dysesthesia

incidence of IAN injury ranges from 0-44% in literature

what are the etiologies of IAN injury?

inadequate planning

overzealous implant planning

miscalculation of nerve position during preoperative radiographic assessment or injury via placing implant drills or fixture too apical to nerve canal

rarely, IAN can be injured from local anesthetic injection, how?

injection injury (duh)

retraction of the gingival flap causing stretching of the mental nerve

in the edentulous/atrophic mandible, the mental foramen may be located at the crest of the alveolar ridge, and it can be at a higher risk of being traumatized from incision and flap elevation

what are various methods that can help prevent nerve injuries?

CBCT or CT scans can be utilized as part of the treatment planning phase to not only plan for implant size, location, and vector of placement but also identify and avoid the mandibular canal

intraoperatively, utilizing CT based surgical guides (presurgically fabricated based on CT evaluation during the treatment planning phase with precise CT based placement of the dental implant with depth control away from IAN) can also protect the IAN

other options include taking radiographs step by step during the procedure with either a drill or positioning locator in place to ensure that the drilling has not gone more apical than planned

if radiographically the IAN canal is violated or it appears that a drill has gone too apical, options include…

using shorter drills for a shorter implant, aborting the procedure with or without a bone graft

clinical assessment can give clues to extent of injury

will cause electric shock like pain in even those with good nerve block- appearance of significant (though transient) bleeding may occur out of osteotomy

if there is gross injury then immediate referral to a microsurgery specialist for treatment

why is topical dexamethasone suggested after iatrogenic nerve damage?

reduce inflammation in the site of injury

what are the possible pharmacotherapy options for nerve perforation?

tricyclic antidepressant drugs, such as amitriptyline, desirpamine, and nortriptyline

serotonin and norepinephrine reuptake inhibitors such as duloxetine and venlafaxine

anticonvulsants drugs, like gabapentin and pregabalin

local anesthetics are often used as a diagnostic tool

topical medications like lidocaine and benzocaine can be helpful in reducing local pain

vitamin B 12 100mcg once daily for one month (cyanobalamin)

sinus/nasal floor perforation

degree dictactes treatment

perforation with the pilot drill is minor- shorten the length of subsequent osteotomies is enough to avoid significant damage to underlying membrane

larger perforations- treated via internal sinus lifts or placing collagen membrane or infusing rhBMP graft at the apex of the osteotomy

nasal floor perforations- associated with minor nasal bleeding, which is often transient

in both situations- sinus precautions postoperatively as well as appropriate antibiotic coverage is indicated

what are the advantages of flapless surgery?

preservation of the blood supply

protection of the soft and hard tissues

shorter surgical times

less postoperative pain

increased patient satisfaction

published reports say pts experience a significant reduction in postoperative pain and swelling and reduction in use of postoperative analgesics

what are complications of flapless surgery?

not being able to fully appreciate the anatomy of the alveolar bone

bild surgical technique

perforation of the buccal or lingual/palatal corticies may occur without the surgeon’s knowledge, compromising the fixture

inability to visualize the crestal bone may result in implants that are too shallow or placed too deep, creating prosthetic problems

how can flapless surgery complications be avoided?

CBCT to determine surgical steps

a virtually surgically planned implant guide, can also ensure placement of the implant into the presurgically determined ideal position and depth

plain dental radiographs immediately following implant placement prior to closure can also help determine whether ideal vertical placement of the implant has been achieved

what are causes of implant fracture?

biomaterial, size, design

abutment screw design, abutment or screw loosening, bone loss versus abutment screw fixation

implant location, parafunctional habits, prosthetic design

localization of the implant, galvanic activity, iatrogenic implant placement or manipulation

how can you manage fractured implants?

removal of fractured implant (replace the implant and manufacture a new prothsesis)

alteration of the existing prosthesis and maintenance of the osseointegrated fracture part

alteration of the fractured implant and remanufacturing of the prosthetic portion

peri-implantitis

an inflammatory process causing destruction of the hard and soft tissue surround the dental implant

clinically stable or symptomatic, mobility of implant, purulent or sero-sanguinous drainage, foul odor, gingival bleeding, rarely pain, surrounding tissues edamtous or tender

what is the etiology of peri-implantitis?

associated with a bacterial biofilm coating the implant

this film has been shown to attach and colonize within minutes to an hour after placement and the exponentially proliferate

how can peri-implantitis be prevented?

maintain excellent oral hygiene

surgeon is responsible for educating the pt on hygiene importance

restorative dentist needs to ensure that the dental prosthesis is easily cleansable and does not create areas for plaque build-up around the implants

peri-implantitis with minimal bone loss and probing depths of less than 4mm

require plaque and calculus removal

polishing of the implant crown

increased oral hygiene visits annually

peri-implantitis with mild bone loss and probing depths of 4-6mm

require increased hygiene visits

chlorhexidine rinses daily

application of chlorhexidine gels to the affected area

peri-implantitis with probing depths of beyond 6mm (with an implant that is still stable)

addition to hygiene and rinsing, systemic antibiotics focused on gram negative coverage (metronidazole) is administered for 10 days

once any suppuration, edema, and/or infection has resolved, it is reasonable to consider guided tissue regenerative procedures with allogenic bone grafting to restore bone height around the implant

if the implant is restored, the restoration should be taken out of occlusion to minimize functional loads

mobility of implants results in implant failure, and removal is required with possible bone grafting if desired

what are the biological markers of failing implants?

clinica, radiographic, microbiological, and biological information

it is a biofilm induced condition- the microbial composition of periimplantitis lesions is mixed, nonspecific, and less diverse than that of periodontitis but includes fusobacterium, prevotella, prophyromonas, streptococcus, campylobacter, neisseria species

often associated with enteric bacteria, spirochetes, and opportunistic (s. aureus)

protein biomarkers detected in peri-implant crevicular fluid provide insight into the underlying biology of the disease and specificity regarding the stage of the disease

tldr, how can complications be prevented?

increase education

seek accreditation

literature review updates

pt information

do not rush treatment

treat for the long term, not the short term

follow up care