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Intraoperative Complications

  • Clinicians should have a strong understanding of surgical and prosthetic implant principles to minimize complications; however, unexpected situations can occur.
  • This chapter discusses the etiology, prevention, and management of complications during treatment planning, surgery, post-op, and maintenance.

Malpositioned Initial Osteotomy Site

  • If the initial implant position isn't ideal, repositioning may be necessary using a Lindemann bur (side-cutting fissure bur) for efficient positional change with minimal bone trauma.
  • After osteotomy preparation, assess proper position with a direction indicator.
Prevention
  • Use surgical templates or implant-positioning devices to prevent improper placement.
  • A pilot surgical guide can help obtain accurate mesial-distal and buccal-lingual positions, especially for clinicians early in their learning curve.
Treatment
  • Conventional drills are difficult to reposition osteotomy sites horizontally.
  • Use a side-cutting Lindemann bur for repositioning, deepening the new osteotomy position to prevent subsequent drills from returning to the original site.
  • Always use copious amounts of saline with a Lindemann bur due to significant heat generation.

Facial Dehiscence After Implant Placement

  • Facial plate dehiscence on the buccal aspect of the implant (crestal area) is not uncommon.
  • Bone resorbs from facial to lingual, sometimes leaving less than 2.0 mm of facial bone after implant placement.
  • A minimum of 2.0 mm of bone is recommended to maintain ideal hard and soft tissue.
  • Facial dehiscence increases susceptibility to peri-implant disease; compromised ridges should be modified to Division A bone before osteotomy.
Treatment
  • Graft sites with autogenous bone if less than 2.0 mm of facial bone exists; bone fragments from surgical drills are ideal due to ease of packing and reduced migration risk.
  • Red or white colored bone signifies live, viable bone. Black or brown bone should be discarded as it is most likely necrotic.
  • Allograft bone is not ideal due to easy migration and added expense.

Loss of Facial Plate When Placing an Implant

  • Fracturing or losing the facial plate is common when placing implants in compromised bone width (Division B bone), compromising healing and longevity.
Prevention
  • Bone width needs to exceed 7.0 mm for a 4.0-mm diameter implant.
  • CBCT examination assesses bone width; site development, including grafting, is indicated to obtain Division A bone.
  • Osteotomy preparation should be in one plane, avoiding angulation deviation.
  • If Division B bone is present, ridge augmentation is recommended before implant placement.
Treatment
  • Treatment depends on the extent of the deficit.
  • Loss of Entire Buccal Plate: Remove the implant and graft the site, followed by implant placement after healing.
  • Partial Buccal Plate Still Intact: Graft the facial area with autogenous bone from the osteotomy site if no implant mobility exists.

Overheating the Bone

  • Overheating bone during osteotomy can cause early implant failure. Bone tissue is susceptible to thermal injuries.
  • Temperature threshold is 47 ∘C47 \,^{\circ}C for more than 60 seconds of drilling; exceeding this limit can lead to necrosis of surrounding bone cells and impair osseointegration.
  • Hyperemia, fibrosis, osteocytic degeneration, and increased osteoclast activity may lead to a necrotic zone around the implant.
Prevention
  • Intermediate Burs: Gradual increase in drill diameter reduces heat and trauma, especially in dense bone.
  • Copious Amounts of Saline: Use internal and external irrigation, with chilled saline for significant heat reduction.
  • Bone Dance: Remove small increments of bone with an up-and-down drill motion to increase irrigation and decrease frictional heat (Misch, 1988).
  • Use of Sharp, New Drills: Dull drills increase heat. Replace drills every 20-30 autoclave cycles, depending on past use.
  • Drill Speed: Use approx. 2000−25002000 - 2500 rpm in hard, dense bone (D1, D2); higher speeds reduce osseous damage and devitalized zones (Sharawy et al.). Slower speeds (approx. 10001000 rpm) are suitable for poorer bone density (Yeniyol et al.).
  • Surgical Templates: Modify templates to allow supplemental irrigation to prevent overheating.
Treatment
  • Remove the implant if excess heat is generated, initiate regional acceleratory phenomenon (RAP), graft the site for future placement, and place a wider implant after sufficient bone width achieved post-RAP.

Implant Pressure Necrosis

  • Overcompression of crestal bone in thick cortical components (D1 and D2 bone) leads to early implant failure and peri-implant disease.
  • Excessive tightening creates compression, impairing microcirculation and causing bone resorption.
  • Pressure necrosis increases the devital zone or causes neurosensory impairment near the mandibular canal.
Prevention
  • Torque: Use a safe torque value of 35 N-cm for most threaded implant designs; unscrew and reinsert if excessive pressure is present.
  • Crestal Bone Bur: Use to minimize stress at the ridge crest due to wider crest module implants.
  • Use of Insertion Wrench: Insert the implant with a hand ratchet, then unthread 3-4 mm to allow bone to creep before reinserting to ideal depth to reduce crestal region force.
Treatment
  • Assess crestal bone thickness and quality via CBCT before osteotomy.
  • Remove implant, modify crestal bone, and reinsert at a lower torque if excess pressure is present.

Injury to Adjacent Teeth

  • Damage to adjacent teeth during implant placement leads to adverse effects, resulting in implant failure or tooth loss.
  • Injury can be direct or indirect (thermal). Direct trauma leads to bone loss, tooth/implant loss, infection, resorption, or prosthetic failure.
  • Improper angulation, insufficient space, bone quantity, or incorrect implant diameter may cause trauma.
Prevention
  • Evaluate adjacent tooth location before implant placement, using CBCT images in the axial plane to measure intertooth distance.
  • Assess angulation using a direction indicator after initial osteotomy (radiograph with guide pin).
  • Use CBCT surgical templates to avoid damaging root surfaces and maintain a minimum of 1.5 mm space between the implant and root surface is recommended.
Treatment
  • Perioperative: Remove and reposition the implant if too close (less than 1.5 mm) to the PDL or tooth structure, ensuring adequate primary stability; graft if necessary.
  • Postoperative/Post-healing: Monitor asymptomatic implants, vital testing of adjacent teeth, remove the implant immediately if the adjacent tooth is sensitive to thermal stimulation or percussion.

Swallowing/Aspiration of Implant Components

  • Aspiration or ingestion of dental components can occur, leading to life-threatening situations.
  • Patients may swallow (usually asymptomatic) or aspirate (coughing, wheezing, etc.).
Prevention
  • Use floss ligatures, special prosthetic instruments, throat packs (4 × 4 gauze), high-vacuum suction, and curved hemostats.
Treatment
  • If an instrument is lost, instruct the patient not to sit up, turn to the side, and attempt to cough it up.
  • Refer the patient for a chest x-ray if swallowed or aspirated.
  • Rigid bronchoscopy is used for removal under general anesthesia if aspirated, it will usually be located in the right bronchus, because the right main bronchus has a more acute angle than the left.

Air Emphysema

  • Air extruded into the sulcular area around implants may lead to air emphysema due to attachment apparatus differences.
  • Subcutaneous emphysema is air introduced into subcutaneous/fascial spaces via an air-driven handpiece or air-water syringe.
  • Symptoms include swelling, crackling feeling, pain, apprehension, and difficulty breathing; crepitus confirms diagnosis.
  • Air may extend to the mediastinum, parapharyngeal, and retropharyngeal spaces, causing airway compromise, or to the pleural space and pericardium, causing heart/lung failure.
Prevention
  • Use an electric handpiece, not air-driven, and avoid placing air into the sulcular area along the long axis of the implant.
Treatment
  • Monitor patients with significant emphysema for respiratory/cardiac distress before discharge.
  • Treatment includes supportive therapy with heat and analgesics; administer antibiotics due to the risk of infection; resolution usually occurs in 4-7 days.
  • In isolated cases, exploratory surgery, tracheotomy, and chest tube placement have been reported.

Electric Handpiece Burns

  • Electric handpieces tend to overheat, potentially causing soft tissue complications.
  • The FDA issued warnings about burns related to electric dental handpieces.
  • Electric handpieces maintain higher efficiency when overworked, generating more heat, and insulated housings mask heat extent from the clinician.
  • Injuries range from first- to third-degree burns and may require reconstructive surgery.
Prevention
  • Be aware of handpiece overheating, take frequent breaks, and check the motor's temperature during treatment.
  • Perform routine maintenance and note that straight 1:1 handpieces have a greater incidence than reduction handpieces.
Treatment
  • Treatment varies based on severity, ranging from over-the-counter ointment to physician referral; severe burns warrant systemic antibiotics.
  • Healing will usually result without a defect given the burn doesn't penetrate the vermillion border.

Monopolar Electrosurgery Units

  • Monopolar electrosurgery is contraindicated near dental implants due to sparking, current spread, and thermal damage.
  • It cuts tissue via an advancing spark with a grounded patient, causing heat.
Prevention
  • Use bipolar electrosurgical units, which use molecular resonance with a sine-wave current, preventing sparking and thermal damage.
  • These units produce progressive coagulation rather than high-output discharge, creating no spark.
Treatment
  • Treatment is palliative because electrosurgery damage is usually irreversible.

Salivary Gland Injury

  • Poor implant positioning in the posterior mandible may injure the sublingual gland, causing a ranula (accumulation of salivary secretions that form pseudocysts in the submandibular area).
  • Ranulas form above the mylohyoid muscle as a translucent, bluish swelling in the sublingual space, and are considered "plunging" when they extend into the neck area.
  • Trauma occurs from improper angulation during implant surgery, perforating the lingual cortex and damaging the sublingual gland.
Prevention
  • Ideal preoperative treatment planning, surgical technique, implant angulation, and careful retraction avoid these complications.
  • Understand sublingual anatomy: gland adjacent to lingual cortex below the mylohyoid muscle; submandibular duct inferior and medial to the gland; lingual nerve crosses the duct.
Treatment
  • Referral to oral and maxillofacial surgeon for removal of the sublingual gland; marsupialization for small, asymptomatic ranulas.

Bleeding-Related Complications

Ideal intraoperative hemorrhage management is prevention through preoperative assessment, meticulous surgical technique, and appropriate post-op care.

Prevention/Treatment

Patients must comply with medication and post-op instructions.

Incision/Reflection of Tissue

Carefully plan incision locations with respect to surgical anatomy; make incisions over host bone to allow for pressure application in case of bleeding.

Flap design should incorporate release incisions to reduce tissue stretching; avoid split-thickness flaps to minimize bleeding.

Carefully evaluate and avoid anatomic areas containing vital structures.

Anatomy/Anatomic Variants

Strategic planning with CBCT helps understand anatomic structures and variants; lack of distortion in CBCT images allows better surgical site planning.

Mandibular Anterior: Intraosseous Vessels

Copious bleeding may occur in the mandibular midline (C position) due to bilateral sublingual arteries entering through the lingual foramen; this is termed the median vascular canal.

Bleeding can be significant but isn't associated with neurosensory impairment; modify osteotomy position if a large anastomosis is present.

Management

If significant bleeding occurs after implant osteotomy in the midline, place a direction indicator or surgical bur into the osteotomy site to apply pressure or introduce an implant into the site.

Inferior Alveolar Artery

The inferior alveolar artery (branch of maxillary artery) divides into mental and incisal branches; its exact location is determined via CBCT.

Management

Drilling or placing an implant into the inferior alveolar canal results in significant bleeding; maintain a 2.0-mm safety zone between the implant and the canal; follow-up post-op is crucial as hematoma may lead to neurosensory impairment.

Incisive Artery

The incisive artery supplies the incisor teeth and anastomoses with the contralateral incisive artery; a large incisive canal may lead to greater bleeding during osteotomy.

Management

If bleeding occurs during implant placement, placing a surgical bur or an implant exerts pressure on the osteotomy.

Mandibular Anterior: Extraosseous Vessels

Life-threatening hemorrhage can occur when a drill perforates the lingual plate, especially in the canine region, traumatizing sublingual or submental arteries.

Bleeding in the anterior region originates from the lingual, facial, or one of its branches; perforation leads to an expanding ecchymosis and potential airway compromise.

Sublingual Artery (Lingual Artery)

A branch of the external carotid, it supplies the sublingual gland, etc. and anastomoses contralaterally; connects with the submental artery.

Submental Artery (Facial Artery)

This branch exists as the largest branch of the facial artery and exits above the mylohyoid muscle and surface; terminates as an artery with the sublingual branch.

Perforating this artery can result to bleeeding which results to haematoma.Perforation causes bleeding, an expanding ecchymosis, and compromises the airway.*

Prevention

Thorough clinical and radiographic evaluation ascertains available bone in the anterior mandible; evaluate implant length to prevent lingual plate perforation or arterial contact; avoid bicortical stabilization; cautiously elevate the lingual flap.

Management

Apply immediate bimanual pressure if the location is known; reposition from supine to upright and administer Young forceps to limit profuse flow outwards; if there remains any airway obstruction, pursue emergency intervention for Ligation of said vessel.

Mandibular Posterior: Extraosseous Vessels

Posterior lingual undercuts may cause problematic, hard to manage bleeding episodes; perforate easily.

Lingual perforation could stimulate a neurosensory infringement.

Prevention

Verify via examination, CBCT images and measurements minimize perforations; carefully visualize this area and maintain proper handpiece control to avoid angulation. Avoid making direct contact towards vessels.

Management

In the event of such bleedings, summon emergency assistance to the bimanual area from the area which vessels protrude (sublingual, submental) as a means to slow the profuse flow. After assistance arrives seek litigation.

Buccal Artery

Damage to the buccal artery may occur during the preparation of any donor autograph; is possible to mitigate this impact if a curved hemostat remains prepped before any implementation.

Prevention

Damage to this artery is mostly inevitable; clamping with the hemostat is often required.

Management

A curved Kelly hemostat is preferred to control the hemorrhage which is normally followed by suturing.

Maxilla: Lateral Wall/Nasal Bleeding

Intraosseous and extraosseous anastomoses formed with the inferior and posterior alveolar may have lateral hemorrhaging; the artery is on average, >23mm from crest before lateral height osteotomy.

Management

Head elevation reduces >38% of blood flow towards sinus region; employ local haemostasis with a diamond bur, or electronic implementation. Suture closed the impacted blood vessel.

Posterior Lateral Nasal Artery

This branch off arterial lines, traverses anteriorly; anastomoses with those from the facial blood lines.

Management

Elevate head and pack the sinus with >4x surgical sponges until any bloodflow is alleviated with no epistaxis. Be aware and inform the risks from such augmentation procedures.

Artery Comprising

Perforating the orbital and nares cavities may require implementing 1:50k lidocaine to control hemodialysis.

Post-operative bleeding

Comprise these events with patient safety as a foundation. It is inevitable for some blood loss during the extraction procedure, however it is up to the technician to set and create best practice outcomes.

*Education before implementing these techniques are key, however a 48 hour check in with anti- coagulants would be a viable plan. For all those in severe shock, replenish intravenous systems to restore any blood.

Monitor any contraindiatorial drugs and agents that lead to bleeding issues.

Techniques to control. Mechanical

Direct, is the best plan; if the flow continues try secondary. Also try sutures, blood vessel tightening, haemotracts and position the patient accordingly to best encourage bloodflow to clot.
Positional changes, patients should be head higher than heart; upright helps reduce haemhorrage.*

Sutures: Direct is paramount from deeper tissue. Indirect is with force however minimal to cause pressure via tissue. Recommend high strength materials such as polyglycolic acid.

Electrical or chemical procedures. Hemostatic procedures by cauterzation is best for this; try not to electrocute yourself though. (Use lowest settings, use Cut Mode for the proper effects.*

Always wear electrical safety gloves, make sure any access is not open. Buzz with the hemostat for cauterziatial, ensure a proper seal.

Always follow technique protocol and laser practices.

Pharmcologic

Usually very consistent outcomes; some have very inconsistent reactions. Monitor from person to person.

A common local anaesthetic is Lidocaine: (has platelet and aldosterone receptors; best utilized to reduce profuse flow. However may create rebound effects).

Tranexamic Acid: Helps form clots, used with mouthwash during post implementations.

Topical Hemsotatic

Absorbalble, direct approach; works most consistent; systemic is added for higher efficacy. There are two types; active and passive