Prevention and Management Of Complications In Implant Dentistry

Prevention and Management Of Complications In Implant Dentistry

Evidence Based Medicine / Dentistry

EBM is the conscientious, explicit and judicious use of best evidence in making decisions about care of individual patients.

Cochrane CenterOxford, England

3 Components of Evidence Based Dentistry

1) Scientific Literature

2) Professional Experience and advise

3) Patient’s treatment desire and goal

“Train The Brain”

Dr. Mark H.E. Lin

Complications In Implant Dentistry

Host / Patient Related

Dentist / Surgeon Related

Clinical Protocol Related

Systemic Conditions

Psychological Status

Smoking Periodontitis

Treatment Planning

Surgical

Local Factors

Grafting

ProstheticRestorative

Maintenance

Medical Status

Absolute Contraindications to Surgery

Relative Contraindications / Risk Factors to Surgery

Host / Patient Related:

Susceptibility to Infections and healing response in question

Medical Status: Absolute Contraindications

For Surgery (Dental alveolar, implant, hard or soft tissue grafting)

– Debilitating diseases:• Active cancer• chemotherapy• radiation therapy• transmittable infections- hepatitis, HIV

– Impaired healing capacity diseases: • Uncontrolled diabetes• Uncontrolled hypertension • immune compromised disease• history of osteomylitis in operative site


Medical Status:

Absolute Contraindications – Recent myocardial infarction (M.I.), cerebrovascular

accident, uncontrolled clotting / bleeding disorders– Pregnancy– Chronic or severe alcoholism– Drug abuse– Psychiatric disorders– I.V. bisphosphonate use or long term oral

bisphosphonate– Uncontrolled periodontal disease– ASA IV or V patients


Medical Status: Relative Contraindications / Risk Factors

For Surgery (Dental alveolar, implant, grafting)

– Debilitating diseases: Inactive cancer– Impaired diseases: Controlled diabetes, controlled

hypertension– Myocardial infarction (M.I.) history of >1 year – Oral bisphosphonate– Smoking habits– Periodontal disease


American Society of Anesthesiologists (ASA) Classifications

ASA I: a normal, healthy patient, without systemic disease.

ASA II: a patient with mild to moderate systemic disease.

ASA III: a patient with severe systemic disease, which limits or alters activity but is not incapacitating.

ASA IV: a patient with severe systemic disease, which is incapacitating and is a constant threat to life.

ASA V: a moribund patient not expected to live more than 24 hours without an operation.

Elective Implant surgeries are NOT indicated for ASA IV or V

patients

For a patient at risk, strict adherence to the standard

protocol does not always yield the expected results.

Infection

Invasion and multiplication of microorganisms in body tissues, which may be clinically inapparent or result in local cellular injury due to competitive metabolism, toxins, intracellular replication, or antigen-antibody response.

Dorland’s Illustrated Medical Dictionary 27th, Edition

Factors Associated with Increased risk of infection for dental implant procedures

Systemic Factors

1. Diabetes2. Long term corticosteroid use3. Immunocompromised systemic disorders4. Smoking5. Malnutrition, obesity6. Elderly population7. ASA III or IV classifications


Local Factors

1. Use of type or procedures of graft material

2. Generalized periodontal disease

3. Tissue inflammation

4. Odontogenic infections

5. ill-fitting provisional prosthesis

6. Incision line opening

7. Inadequate oral hygiene


Surgical Factors

1. Poor aseptic technique

2. Compromised skill and experience of the surgeon

3. Increased duration of surgical time

4. Wound contamination during surgery

5. Foreign body introduction (graft material, implants, debris, etc….)

Infection Prophylaxis

1) Aseptic Surgical techniques applied during all clinical grafting procedures.

2) Pre-operative Rx: Amoxicillin 500mg x 4 tablets (2 g), 1 hour prior to

surgery (Scientific Evidence)Post-operative 1 tablet t.i.d. for 1 week following surgery (Optional)


3) Chemical Plaque control: Preoperative rinsing with .12%

Chlorhexidine digluconate for 1 minute.

Postoperative rinsing for 2-3 weeks with good oral hygiene.

4) Monitor and close follow up:Patient to return to clinic at 1-2 weeks to evaluate healing status.


5) Confirm lack of localized infection from adjacent tooth (endodontic origin) or soft tissues (periodontitis) spreading into grafting site.

Diabetes

1. Higher prevalence in Adult African Americans, native and Hispanic Americans

2. Risk factors: Genetics, obesity, advancing age and inactive lifestyles.

3. Characterized by:1. Peripheral resistance to insulin

2. Increased production of glucose by the liver

3. Altered pancreatic insulin secretion.

Oral Manifestations for a Diabetic Patient

1. Poor wound healing (soft tissues, osseointegration)

2. Higher susceptibility to oral infections

3. Xerostomia

4. Higher incidence of dental caries

5. Pronounced hyperplasia of attached gingival

6. Increased accumulation of plaque and food debris

7. Neuropathy (burning mouth, tingling, numbness)

8. Greater incidence and severity of periodontal disease

9. Candidiasis and lichenoid reactions

Signs of Hypoglycemia:

1. Sweating

2. Palpitations

3. Tachycardia

4. Nausea

5. Hunger

6. Tremulousness

7. The symptoms may progress to coma and convulsions without intervention.

Management of type I diabetic patients: (To prevent Insulin shock)

1. Patient instructed to take their usual dosage of insulin medications

2. To eat a normal meal prior to appointment

3. Schedule the appointment early in the morning

4. Patient to communicate with dentist if they feel symptoms of an insulin reaction

5. A source of sugar available in office (orange juice, candy, sugar packs)

6. May consider Antibiotic prophylaxis coverage to prevent infections which is related to the fasting blood glucose levels.

Dental Managements

1. Minimize stress

2. Decrease risks of infection (Post operative antibiotics: Amoxicillin 500 mg, t.i.d. or Clindamycin 300 mg, t.i.d. for 7-10 days)

3. Avoid untoward metabolic imbalances during dental therapy

4. Instructions for diet and medications to avoid hypoglycemia.

Management of Hypoglycemia

1.Sugar source readily available (sugar packets, candy, orange juice)

2.Dextrosol 3mg tablets of glucose

3.Glucagon 1 mg IM

4.50% Glucose solution 50 ml IV

Bisphosphonates Induced Osteonecrosis of the Jaws (ONJ)

Defined as a non healing bone in the mandible or maxilla present for 8 weeks in a person that is on Bisphosphonates and

hasn’t received radiation to the jaws.

Risk of osteonecrosis of the jaws

• Exposed bone is dead with usually no pain.

• Pain may occur due to secondary infection

• The jaw bones are susceptible because the jaw bone remodels 10 times that of long bones in the body.

Bisphosphonates

• Used for treatment of osteoporosis, metastatic bone cancer and Paget’s disease.

• Oral form: Fosamax, Boniva, Actinol

• IV form: Aredia, Zonita

Mechanism of Bisphosphonates

• Mechanism of action by suppressing and reducing bone resorption by osteoclasts.

• Bisphosphonates inhibit osteoclasts by killing them when they take up the drug during resorption.

• Bisphosphonates binds to the hydoxyapatite in the bone

Bisphosphonates

• IV medications are worse then oral types.• Risk increase after being on oral medications

for > 3 years.• IV takes 6 months to build to toxic level• Oral takes 3 years to build to toxic level

• 140 IV reported cases versus 40 Oral cases

• Incidence: IV: .8%-12%• Incidence: Oral: .01%-1%

Signs of ONJ

• Sclerosis and thickening of the lamina dura

• Widening of the periodontal ligament (PDL)

• Mobile teeth with pain

• Exposed bone with necrosis of bone and soft tissues

• Non healing bone post surgical wound

Treatment of ONJ• We don’t know what is the best treatment protocol.

Dr. Robert Marx seems to be the expert on this topic.• Peridex rinse over surgical wound

• Antibiotics: a) Pen VKb) Levoquin (limit to 21 days due

to liver toxicity)

• Reduce risk of secondary infections and osteomylitis of the jaws.

• 50 % of cases will spontaneously heal.• 50 % of cases will require additional surgeries.

Prevention of ONJ

• Non invasive dental procedures are safe.

• Invasive dental procedures safe before 3 years.

• After 3 years- a drug holiday with consent of prescribing physician to a CTX of >= 150 pg/ml.

Serum C terminal telopeptide test (CTX)

• After 3 years of Bisphosphonate use, need a CTX to determine safety level.

• CTX <= 100 pg/ml: HIGH risk• CTX = 101-150 pg/ml: Moderate risk• CTX >= 150 pg/ml: Low risk

• CTX improves significantly with discontinued oral Bisphosphonates use.

• CTX is a marker for bone turnover and healing.• Measures osteoclast function as a C terminal fragment

is cleaved during bone resorption.

Suggested Treatment Regimen

• 1) Obtain references for CTX level

• 2) Drug holiday of 4-6 months with approval from prescribing physician.

• 3) Treat with Peridex (.12%) and antibiotics.

• 4) Monitor CTX until value is >150 pg/ml

• 5) Decide to refer or monitor for treatment options:

A) Spontaneous resolution

B) Treat surgically


1. Psychological and mental stability for patient to accept and tolerate required procedures

2. Normal healing response and sequelae of bone and soft tissue grafting procedures

3. The 3 “C’s” prior to treatment:a) Communicationb) Compliancec) Consent


Normal healing response and sequelae of bone and soft tissue grafting procedures are:

• Hemorrhage / bleeding

• Ecchymosis / bruising

• Pain / discomfort

• Swelling


Hemorrhage / bleeding Management

1) Management of intra operative bleeding source (soft tissue / bone) prior to suturing.

2) Proper soft tissue suturing techniques to ensure primary closure without tension of soft tissues.

3) Proper use of sterile gauze pads with moistened sterilesaline solution with FIRM pressure over wound for 20 minutes.

4) Oral and written instructions for care to prevent vasoactive substance (caffeine or alcohol), minimize exercise, post operative care to minimize disturbance to wound clotting, oral hygiene instruction care.

Ecchymosis (Bruising)

• Due to extravasation and subsequent breakdown of blood in the subcutaneous tissues.

• Deposition of blood from the surgery in the interstitial tissues spaces and will be resorbed over a time period of 1-3 weeks.

• Occurs more in fair skinned patients and elderly patients with fragile capillaries.

Ecchymosis Management

1) Inform patient that it will be a normal sequelae of any surgical procedure.

2) Inform patient that degree of bruising is NOT an indicator of success / failure, traumatic / atraumatic nature of procedure or operator.

3) Application of ice bag or cold packs immediately after surgery for 2 days.

Pain / discomfort Management

1) Long term Local anesthetics:a) Bupivacaine (Marcaine / Vivacaine): 0.5% w

1:200,000 epinephrine used for block anesthesia. Duration time of 6-8 hours.

b) Articaine (Ultracaine Forte / Astracaine): 4% w 1: 200,000 epinephrine. Duration time of 4 hours.

2) Analgesics:a) NSAIDS: Ibuprofen 400mg (600-800mg if anticipate

swelling), 1 hour prior to surgery, then 1 tablet every 6-8 hours continuous for 2-3 days.

b) Narcotics: Tylenol #3, 1-2 tablets every 4-6 hours as required for pain relief.

Swelling Management 1) Application of ice bag or cold packs immediately after surgery

for 2 days.

2) I.V. administration of glucocorticoid steroids (prednisolone 250mg or dexamethasone 8 mg) prior to start of surgery.

3) I.M. administration of Dexamethasone / Decadron (Celestone Soluspan Injectable)6mg/per site adjacent to surgical

wound.

4) P.O. prescription of Dexamethasone (Decadron) 4 mg with regimen as follows:

– Preoperative 4mg x 2 tablets = 8 mg, 1hour prior to surgery– Postoperative 4mg x 1 tablet = 4 mg, 1st day after surgery– Postoperative 4mg x .5 tablet = 2 mg, 2nd day after surgery– Postoperative 4mg x .5 tablet = 2 mg, 3rd day after surgery

Complication

A secondary disease or condition aggravating an already existing one.


Complication

Defined as a secondary condition that developed during or after implant surgery or prosthesis placement. The occurrence of a complication does not necessarily indicate that substandard dental care was provided and also does not necessarily mean that clinical failure has occurred.

Sequelae

Any lesion, condition, consequence or affection following a clinical procedure injury or caused by an attack of previous disease.


a) Communication

Share or exchange information, news, or ideas

Oxford Dictionary 10th Edition

Allocate appropriate amount of TIME to educate and communicate prior to consent to treatment. Utilize patient education video, documents and software to aid in communication process.

b) Compliance

Disposed to agree with others or obey rules, especially to an excessive degree. Meeting or in accordance with rules or standards.

Oxford Dictionary 10th Edition

A quality of yielding to pressure or force without disruption, or an expression of the measure of the ability to do so.


COMPONENTS OF CASE MANAGEMENT FOR IMPROVED CASE ACCEPTANCE RATE

New Patient Telephone Interview

New Patient First Appointment Interview/ Consultation Interview

Diagnostic Records Appointment

Case Presentation(Within 1 Week), (Bring Spouse)

Acceptance Pending

Case Discussion LetterPre-Appointment Work Up

-Pre Medications-Inform Consents-Financial Arrangements Confirmed-Diagnostic Work Up-Q/A Period

Treatment

Post Treatment Interview-Follow Up photos for Patients B/A-Request for Testimonial Letter-Referral Request

Follow Up Report(1wk, 2 wks, 1 months)

- Consult with Specialists and Labs

c) Consent Process

1. Communication and patient education

2. Process of informed consents and financial arrangements confirmed

3. Relationship and rapport development with patients

4. Continuous monitoring support, empathy and sincere compassionate care

Consequences of Smoking on wound healing

1. Arteriolar vasoconstriction reduces vascularization and microcirculations of tissues.

2. May lead to increase incidence of flap necrosis and dehiscence to early graft exposures.

3. Tobacco's toxic byproducts have been implicated as risk factors for impaired healing.

Studies on Smoking and Implants

Study # 1: 5% lost on non-smokers versus 11% on smokers. Smokers with higher implant failure rates in all regions except for the posterior mandible.

Study # 2: 3% lost on non-smokers versus 7% on smokers by number of implants. 9% lost on non-smokers versus 22% on smokers by number of patients. Regardless of method of analysis, a SIGNIGICANT difference was noted between smokers and non-smokers.

Studies on Smoking and Implants

Study # 3: Smoking cessation protocol of 1 week before surgery and 8 weeks after surgery.

-6% implant lost on non-smokers.

-38% implant lost on smokers WITHOUT smoking cessation program.

-12% implant lost on smokers WITH smoking cessation program.

Cessation protocol demonstrated improving implant success on treatment of smokers.

Effect of smoking (evaluated in 9 studies)

-Significantly increases implant loss

-Consumption increases failures (2 studies)

-Consumption does note increase failure (1 study)

-Comparison (smokers/nonsmokers)178 / 1668 implants lost in smokers (11%)

239 / 4862 implants lost in non-smokers ( 5%)

Management protocol for smokers

1) Don’t treat!

2) Smoking cessation programs

3) Treat with consent form

Tobacco and Nicotine Warning Consent forms

Nicotine and Tobacco Warning

The nicotine in tobacco constricts the blood vessels of your body. This effect is immediate and lasts up to one month. Furthermore, nicotine will reduce the amount of oxygen delivered to the body. This constriction of blood vessels and reduced oxygen delivered will affect the circulation of the tissues handled. Implant surgery and bone grafting may require extensive manipulation of soft tissues. The use of nicotine can compromise the healing and cosmetic outcome of these surgeries. YOU MUST STOP SMOKING one month prior to surgery. You must not smoke for at least three weeks following surgery. A nicotine patch may be used to help stop smoking. However, no nicotine patch or nicotine gum may be used one month prior to surgery and for three weeks after surgery. ________________________ _______________________ Parent Signature Date ________________________ _______________________ Witness Signature Date

Periodontal disease and Dental Implants

1. Implant survival in patients with a history of treated Periodontitis ranged from 59-100%

2. 17/18 studies reported high implant survival rates of >= 90% with turned or moderately rough implant surfaces

3. Need for continue regular supportive periodontal therapy

4. Statistically significantly greater risk of peri-implantitis, odds ratio of 3.1 to 4.7

Iatrogenic

Any adverse condition in a patient occurring as the result of treatment by a physician / dentist or surgeon, especially to infections acquired by the patient during the course of treatment.


Implant Treatment Planning

Implantology is a “Prosthetically / Restorative” driven discipline with a “Surgical” component.

Treatment Sequence

Esthetic Implant Dentistry, Patrick Palacci, DDS

Improper Implant Treatment Planning

1) Improper surgical implant placements without desired prosthetic goals treatment planned

2) Improper use of number and location of dental implants for final prosthesis

3) Lack of understanding of Biomechanical rationale requirements for functional loads

Pretend the following:

-you had all the time -you had all the money-you had all the bone

-you had all the compliance

What is the most ideal treatment plan desired for

your patient?

Treatment planning philosophy- one of the most important factor to success

• Don’t compromise your ideal treatment plan with the following:

• -patient’s financial constraints.

• -unreasonable time demands for completion.

• -insurance limitations or moral compromises.

• -patient’s guidance on treatment decisions.

• (i.e. less implants, omit required grafting, use of material, etc….)

“The Lost Syndrome”1) Lost trust from the patient!

2) Lost patience from the patient who will require more surgeries and procedures!

3) Lost time and require to start again from a clinical condition in a MORE compromised state!

4) Lost clinical chair time to redo the case!

5) Lost lots of money to redo the case!

6) Lost of peace of mind! (Lawsuit or Regulatory College Complaint?)

Treatment planning philosophy- one of the most important factor to

success

My rule on Treatment Planning

Only treatment plan and execute implant treatment as you would for your own family members.

Improper use of number and location of dental implants for final prosthesis

Lack of understanding of Biomechanical rationale

requirements for functional loads

Biomechanical rationale

Definitions• Bone Remodeling- turnover or

internal restructuring of previously existing bone.

• It is a coupled tissue level phenomenon.• Activation- of osseous precursor cells.• Active Resorption.• Reversal or Quiescence.• Formation.

• Remodeling cycle called “Sigma”- in humans is 17 Weeks.

Definitions• Strain- the change in length divided by

the original length and the units of strain are given in percent.

• Too much bone strain at the implant interface causes bone loss.

• The strain to bone may be caused by the stress applied to the prosthesis.

Stress = _____

Mechanism of Implant Failure

Occlusal overload

Microdamage

Increased bone remodelling rate

Histological change in boneat implant interface and adjacent bone

Increased effect of magnitude of strain

Stress Factors• Excess stresses to an implant / bone interface will cause

overload and implant failure.

Complications from Stress:• -implant integration failure with fibrous tissue formation

around implant, mobility instead of rigid fixation.• -Early crestal bone loss.• -Occlusal overload bone loss• -Screw loosening (prosthesis or abutment)• -Implant fracture (body or component)• -Prosthesis fracture (occlusal material or framework)

5) Clinical Force factors

• 1) Bite Forces (light vs. normal vs. heavy)• 2) Parafunction• 3) Crown implant height ratio• 4) Masticatory Dynamics• 5) Opposing Arch• 6) Direction of load• 7) Nature of Opposing Arch• 8) Position of Abutment in the arch• 9) Occlusal scheme

1) Bite Forces (light vs. normal vs. heavy)

• Implant supported Fixed Prosthetics >

• Implant supported Removable Prosthetics >

• Natural dentition with Porcelain Prosthetics >

• Natural dentition >

• Partial Removable Prosthetics >

• Full Removable Prosthetics

2) Parafunction Repeated or sustained non-functional wear that is harmful to the stomatognathic system.

– A) Bruxism- vertical or horizontal nonfunctional grinding of teeth. A maximum bite force recorded at 990 psi (4-10 times normal)

– B) Clenching- a habit that generates a constant force exerted form 1 occlusal surface to the other without any lateral movement. Bruxing and clenching can exist in combination.

– C) Tongue Thrust and Size- unnatural force of the tongue against the teeth during swallowing.

Character Of Forces• A) Force Magnitude (heavy, medium, light)

• B) Force Duration

• C) Force Type (Compressive, tensile, shear)

• D) Force Direction

• E) Force Magnifiers (Horizontal and vertical cantilevers)

Surface Area for maximal Bone / implant interface

contacts

Options To Increase Surface Area

• 1) Increase Implant Numbers

• 2) Increase Implant Size and Length

• 3) Implant Design

• 4) Implant Surface conditioning

• 5) Bone Density

Surface Area for maximal Bone / implant interface contacts.

1) Maximize implant number.2) Maximize implant diameter.3) Maximize implant length.

(Without violation of the limits of bone volume or anatomical structures.)

4) Bone Density Classification

D1- Dense cortical ( > 1250 Hounsfield units)D2- Porous cortical and coarse Trabecular ( 850-1250 H. units)D3- Porous cortical (thin) and fine Trabecular (350-850 H. units)D4- Fine Trabecular (< 150 H. units)

Goals of Diameter Of Implant1. Increase surface area

2. Compensate for unfavorable patient bite force factors

3. Minimize cantilevers for angled implants

4. Compensate for poor bone density

5. Enhance surface for shorter implants

6. Improve emergence profile

7. Decrease screw loosening

8. Minimize component fracture

9. Facilitate oral hygiene

Approximate Surface Area Of Anterior Natural Dentition (mm2)*

• Jepsen, A root Surface Measurement and a Method for x-ray determination of Root Surface, Acta Odontol., Vol.21:35, 1963

Position Central Lateral Cuspid

Maxilla 204 179 273

Mandible 154 168 268

Approximate Surface Area Of Posterior Natural Dentition (mm2)*

• Jepsen, A root Surface Measurement and a Method for x-ray determination of Root Surface, Acta Odontol., Vol.21:35, 1963

Position First Premolar

Second Premolar

First

Molar

Maxilla 234 220 443

Mandible 180 207 431

Goals of Length Of Implant1. Increase surface area

2. Compensate for unfavorable patient bite force factors

3. Gain initial ridged fixation of dental implant

4. Compensate for poor bone density

5. Not violate any vital anatomical anatomy (IAN, mental nerve, sinus, lingual concavities, nasal foramen, adjacent roots, etc….)

Failure Success

•Poor Bone Site Selection Short, Narrow, Porous

•Bone Site Selection High, Wide, Dense

•Implant Design Oversized implant

•Implant Choice/Design Bone around implant

•Poor Surgical Technique •Surgical Technique Proper implant placement Adequate healing time Sterile technique

•Poor Prosthetic Technique •Prosthetic Reconstruction Biomechanical design Occlusal relationships

•Poor Patient Cooperation •Patient Hygiene / Recall

Classification Of Oral Implant Failures

• 1) Biological:

• A) Early or Primary (before loading): Failure to establish osseointegration.

• B) Late or Secondary (after loading):Failure to maintain the achieved osseointegration.

Early or Primary (before loading): Failure

to establish osseointegration.

• 1) Inadequate quantity and quality of bone for initial fixation of dental implant.

• 2) Experience of surgical operator.

• 3) Over heating of bone during osteotomy preparations.

• 4) Pressure necrosis, especially in D1 bone.

• 5) Infection operatively after initial surgery.

• 6) Incision line opening leading to complications or infections.

Goodacre C, JPD 2003

Classification Of Oral Implant Failures

• 2) Mechanical:

• Fracture of implants, connecting screws, bridge frameworks, coatings, porcelain, etc….

Goodacre C, JPD 2003

Iatrogenic

1) Treatment planning flaws and complications.

2) Violation of vital anatomical structures.

3) Inappropriate application of procedure to site requirement.

4) Compromised surgical skills.

5) Compromised prosthetic skills.

Types of Surgical Complications

A) Surgical complicationsB) Hemorrhage-related complicationsC) Neurosensory complicationsD) Mandibular fractureE) Adjacent Tooth devitalizationF) Life-Threatening hemorrhageG) Air EmboliH) Violation of Mandibular canalI) Aspiration of screwdriver, parts,

components

Surgical Parameter by REGIONS

Posterior Mandible

Surgical Parameter by REGIONSPosterior Mandible

D2 –D3 bone density• 1) Problem: Mandibular nerve location.

• Solution: Surgical landmark to be at least 2.0 mm above the mandibular canal to establish a surgical zone of safety.

• Pre-surgical diagnostic workup to measure allowed length of implant. Use of periapical and panoramic x-rays, tracings, CT scans to verify length.

• Surgical use of directional guide pins to verify proximity to mandibular nerve after initial pilot osteotomy.

• Remember: “The enemy of good is perfection.” If in doubt, use shorter implant lengths ( at least 10.0 mm)

Posterior Mandible

Factors to Consider in Zone

Potential Complications

Treatment Options

Damage to Inferior Alveolar Nerve (IAN)

Damage to Mental nerve

Paraesthesia Surgical landmark to be at least 2.0 mm above the mandibular canal to establish a surgical zone of safety

Use of Periapical and panoramic x-rays, tracings, CT scans to verify length.

Surgical use of directional guide pins to verify proximity to mandibular nerve after initial pilot Osteotomy.

Surgical Parameter by REGIONSPosterior Mandible

• 2) Problem: Lingual concavity and angulation flare of posterior mandible.

Solution: Use of CT scans to perform electronic surgery as part of treatment planning. Minimal reflection of lingual flap to visualize lingual wall of bone trajectory. Implant length to meet biomechanical requirement without anatomical violations.

Posterior Mandible



Treatment Options

Perforation of Lingual concavity

Profuse uncontrollable bleeding

Damage to Lingual nerve

Use of CT scans or tomography films identify anatomical concavity

Surgical use of directional guide pins to verify angulation

Reflection of flap to palpate and measure concavity undercut

Contraindications to posterior single –tooth implant

• 3) Inadequate bone volume –

• Width-consider grafting or alveloplasty or implant placement with guided bone regeneration.

• Length- Mesialdistal, intratooth space, need >7 for a 4.0mm implant with 1.5mm between implant and adjacent tooth.

• Height- no treatment, shorter implants, or particulate grafting of exposed threads.

Posterior Mandible



Treatment Options

Inadequate Width of Buccal bone volume

Buccal threads of implant exposed

Soft tissue irritation

Continuous lost of buccal plate after functional loading

GBR technique to graft buccal aspect after implant stability achieved

Alveoloplasty of platform to gain width and interocclusal space

Use of smaller diameter implant to accept compromise (>4.0 mm)

Posterior Mandible



Treatment Options

Inadequate Height of vertical bone volume

Violation of IAN

Increased crown / implant ratio with increased vertical cantilever

Use of shorter implants

No treatment for implants with “shorten dental arch concept”

GBR of vertical exposed threads (unpredictable)

Angulated implants

Nerve Repositioning


Anterior Maxilla

Buccal / Palatal Position:

Implant platform to be at INCISAL EDGE with 1/3 buccal to edge and 2/3 palatal to edge of adjacent teeth.

Mesial / Distal Position:

1.5-2.0mm between implant and adjacent tooth, 3.0mm between 2 adjacent implants.

Apical / Coronal Position:

Implant platform to be 3.0 mm apical to free gingival margin of adjacent teeth or ideal position.

Position of Implant placement in 3 DIMENSION

Implant Position Related To Retention Mechanism

Cement retained

Buccal / Palatal Position:Implant platform to be at INCISAL EDGE with 1/3 buccal to edge and 2/3 palatal to edge of adjacent natural dentition.

Screw retainedBuccal / Palatal Position: Implant platform to be at CINGULUM aspect relative to adjacent natural dentition.

Maxillary Anterior



Treatment Options

Exact implant position placement requirement for HIGHLY esthetic demanding prosthetic results

Too Shallow

placement leads to interface showing

Soft tissue thin biotype recession risks

Compromised emergence profile

Placement of implant platform to level of 3.0 mm apical to adjacent free gingival margin

Use of screw retain due to lack of interocclusal space

Maxillary Anterior



Treatment Options


Too Deep

placement leads difficulty in cement clean up

Creation of deep soft tissue pocket inaccessible by oral hygiene aids

Use of screw retain to avoid need for cement

Use of custom abutment to raise level of desired margin of crown for cement option

Use of pre-mucosal extensions (PME) abutments to raise crown margin

Maxillary Anterior



Treatment Options


Too Buccal placement will lead to inappropriate emergence profile of prosthetic crown

Buccal bone with potential dehiscence and soft tissue recessions

Avoid by use of Lindenman drill to counteract dense palatal bone

Use of customized UCLA abutment to offset poor angulation

Use of screw retained crown with access hole through facial aspect

Remove implant

Maxillary Anterior



Treatment Options


Too Palatal placement will compromise lingual bulk of final prosthesis

Potential phonetic interferences

Creation of ridge-lap over buccal aspect

Potential violation of incisive foramen/canal

Screw retain prosthetic implant crown

Use of customized UCLA abutment to correct emergence profile

Removal of implant

Palatal placement requires ridge lap and compromised phonetics


Anterior Mandible

Surgical Parameter by REGIONSAnterior Mandible

• D1-D2 bone density• 1) Problem: Overheating during

osteotomy preparations.

– Solution: Prepare osteotomy with constant pumping motion

and use higher torque speed. Use new

drills with copious COOLED irrigations and

incremental drill sequence.


• 2) Problem: Pressure necrosis of devital zone of bone around implants. (Early signs of RL around implants during healing with symptoms of pain to patient.)

• Solution: Must bone tap with hand ratchet each osteotomy site prior to surgical implant placement. Reverse torque final implant position by 1/4 - 1/2 turn to relieve internal stresses

and pressure.

Maxillary Anterior



Treatment Options

Dense D1 bone density

Overheating of bone causing bone necrosis

Over pressure of bone causing pressure necrosis of devitalized bone around implant

Prepare with high torque speeds

Use new sharp drills

Copious cooled saline irrigation with pumping motion

Use specialized dense bone drills

Bone tap prior to implant placement

¼ back turn of final implant position to release stress

Surgical Technique Specific For D1-D2 Bone Types

• 1) Use new and sharp drills for osteotomies.• 2) Use chilled saline with internal and external

copious irrigation.• 3) Use “Pumping” motion to allow osteotomies to

cool down between advancement in depth.• 4) Use marginal enlargement of osteotomies with

sequential drill sizes.• 5) Must bone tap prior to implant placement.• 6) After initial implant placement, reverse torque

implant by ¼ - ½ turn.• 7) Can consider immediate or early loading.


• 3) Problem: Resorption pattern of anterior mandible resulting with lingualized implant angulations and position.

• Solution: Fabrication of Surgical guides from approved wax up of final prosthesis. May need to compromise with thicker amount of lingual acrylic.


• 4) Problem: Resorption pattern or anatomical pattern resulting in steep lingual concavity.

• Solution: Pre-surgically diagnose situation with use of lateral ceph radiographs or CT scans. Surgical reflection of lingual flap with direct vision inspection and instrument protection.

Resorption pattern

Anterior Mandible



Treatment Options

Perforation of Lingual concavity

Profuse uncontrollable bleeding

Damage to Lingual nerve and artery

Use of CT scans or tomography films identify anatomical concavity

Surgical use of directional guide pins to verify angulation

Reflection of flap to palpate and measure concavity undercut


• 5) Problem: Location of Mental foramen with or without anterior loop.

Solution: Locate the mental nerve by anatomical location relative to the face. Vertical line through pupils of the patient’s eyes passes through infraorbital and mental foramen. Finger width lateral to ala of the nose also is on this vertical landmark.

Surgical dissection to identify and locate the mental nerve with safety zones marked.

Anterior Mandible



Treatment Options

Location of mental foramen and nerve

Paraesthesia to innervations supply of mental nerve

Identify the mental foramen and provide zone of surgical safety of >3.0 mm

Surgical reflection to identify and protect mental foramen and contents


Posterior Maxilla

Surgical Parameter by REGIONSPosterior Maxilla

D3-D4 bone density:

1) Problem: Violation of Maxillary Sinus

Solution: Determine need for sinus augmentations prior to implant placement.

Need minimal of 5.0 mm of autogenous recipient bone for simultaneous implant placement with sinus graft.

Posterior Maxilla



Treatment Options

Compromised height due to violation of maxillary sinus

Radiographs, CT scans to determine treatment plan to manage lack of height

Sinus augmentations

Angulated implants

Short implants

No Treatment and utilize “shorten dental arch concept”

Surgical Parameter by REGIONSPosterior Maxilla

• 2) Problem: Bone density with least implant contact (50%).

Solution: Use a bone condensing (osteotomes) rather than bone removing

(osteotomies) technique for implant site preparations.

Posterior Maxilla



Treatment Options

D3, D4 bone type, least density of all

Posterior zone with high bite forces

Biomechanical complications due to high bite force

Least amount of bone implant contact (BIC)

Don’t use final drill size for desired implant diameter to use compressive forces of implant insertion into smaller Osteotomy

Use of tapered implant design or aggressive thread design (Nobel Active Implant)

Extend healing periods

Implant Prosthetic Implant Prosthetic concepts concepts

Implant Prosthetic Concepts

1) Minimize ( < 3 units )Minimize ( < 3 units ) number of pontics.

2) No Cantilevers (especially distal)

3) No Connection to natural teeth.

4) Splinting of implant crowns.

5) Minimize facial / lingual occlusal table.

6) Implant protected occlusal scheme.

7) Progressive bone loading concept on softer bone.

Splinting of implant crowns

Splinting of implant crowns

Don’t Do This!

4) Occlusal load axial to implant body angle

5) Low cusp angle of crowns

7) Cantilever or offset distance ( Horizontal offset)

Indications For Open Tray Impression Technique

1) Require adequate access for prosthetic open tray impression copings. (Anterior regions of mouth.)

2) Multiple units to register accurate relationship by indexing of impression copings.

3) Allow impressions with Divergent angulated dental implants.

4) Usually require custom impression trays or altered disposable trays.

5) Must verify seating with radiograph

6) Consider indexing with resin pattern

Indications for Closed Tray Impression Technique

1) Require minimal access for prosthetic closed tray impression copings. (Posterior regions mouth.)

2) Single or quadrant units.

3) Allow impressions with Parallel alignment of dental implants.

4) Usually require stock impression trays or disposable trays.

5) Must verify seating with radiograph.

6) Plug screw hole to avoid positive impression registration

Implant Protected Occlusion• 1) No premature occlusal contacts or interferences.

Timing of occlusal contacts protected by natural dentition.

• 2) Influence of surface area• 3) Mutually protected articulation (No lateral excursion)• 4) Occlusal load axial to implant body angle • 5) Low cusp angle of crowns• 6) Crown Height (vertical offset)• 7) Cantilever or offset distance ( Horizontal offset)• 8) Implant crown contour (narrow B /L dimensions)• 9) Selection of occlusal materials• 10) Verify implant supported prosthesis have lightened

occlusion where shim stock (12 um) pulls through in C.O. or M.I.P.

Implant Protected Occlusion

The Maintenance Requirement1) Post insertion 1 week later- verification of soft

tissue health and implant protected occlusion

2) Post insertion follow up every 4 months for the first year after loading of prosthesis- verification of crestal bone changes with radiograph, soft tissue health and implant protected occlusion

3) Post insertion follow up every 6 months for the second year and beyond.

3) Prosthetic Parameters:3) Prosthetic Parameters:

Biomechanical rationaleBiomechanical rationaleImplant Prosthetic conceptsImplant Prosthetic conceptsImplant provisionalization optionsImplant provisionalization optionsOpen versus Closed tray impressionOpen versus Closed tray impressionScrew versus cement retentionScrew versus cement retentionImplant protected occlusionImplant protected occlusionManagement protocol for parafunctional Management protocol for parafunctional habitshabitsManagement Options For Compromised

Interocclusal distance

Management protocols Management protocols specific for patients with specific for patients with

parafunctional habitsparafunctional habits

Force Factors

1) Magnitude (light, normal, heavy)

2) Duration (day time, night time)

3) Frequency (number / unit time)

4) Direction (vector of forces)

5) Type (compression, tensile, shear)

6) Magnifiers (height, cantilevers, parafunctional habits)

6) Combination

Strategies To Manage Parafunction Forces1) Educate patient of parafunctional habits.2) Placing increased number of implants.3) Placing larger diameter implants.4) Placing implants in positions to reduce bending overload

or positions to promote axial loading.5) Avoid use of cantilevers or pontics.6) Use bruxism night guard appliances.7) Increasing time intervals during prosthetic restoration

stages for progressive loading protocol.8) Paying diligent attention to occlusal contact design for

“Implant Protected Occlusion” and axial loading.9) Alter occlusal material of prosthetic teeth to be acrylic

resin for removable prosthesis and metal occlusal for fixed prosthesis.

Incidence Rate Of Mechanical Complications

1) OD loss of retention or adjustments 30%

2) Resin acrylic veneer facture of FPD 22%

3) OD relines required 19%

4) OD clip / attachment fractures 17%

5) Prosthesis screw loosening 7%

6) Abutment screw loosening 6%

Implant Prosthetic Complications

Complication Etiology Solution

OD loss of retention or adjustments (30%)

Lack of Simultaneous contact engagements of attachments with differential wearing of component parts

Pick up attachments to be parallel

Use customized abutments to correct for unparallel implant placements



Acrylic Fractures Inadequate interocclusal distance from implant platform level to opposing cusp

Osteoplasty prior to implant placement to increase interocclusal distance

Consider different attachment options that require less interocclusal distance (Locator attachments)

Need >2.0 mm acrylic resin thickness over attachments for strength

Space Requirements for Bar-Overdenture• -Thickness of soft tissue 2.0 mm• -Hygiene space under bar 1.5 mm• -Thickness of bar 4.0 mm• -Clip and housing 1.5 mm• -Acrylic denture base 2.0 mm• -Denture tooth 3.0 mm

• Total Height Requirement =14.0 mm

• Compromised Height is 10.5-14.0 mm (bar touching soft tissue, reduce thickness of bar, attachment type altered, reduce thickness of acrylic base and denture tooth size.



Porcelain Chips and Fracture

Resin acrylic veneer fracture of FPD (22%)

Unsupported substructure

Heavy occlusion for implant restoration

Steep cusp angles with lateral excursion forces

Substructure extension to support porcelain of less than 2.0 mm thickness

Confirm implant protected occlusion

Shallow cusp angles with narrow occlusal table to avoid lateral forces




Inadequate interocclusal clearance for abutment, substructure and porcelain

Zirconia with higher incidence of porcelain shear fractures

Treatment plan options to manage interocclusal distance

Screw retain option

Metal occlusal

Osteoplasty prior to surgery to submerge implant platform level

Inter-Occlusal Space Recommendations

• 1) < 3.0 mm abutment height- Use screw retention.

• 2) 3.0-4.0 mm abutment height- Use screw retention or vary cement type to make non-retrievable.

• 3) > 4.0 mm abutment height- Use retrievable cement.



OD relines required (19%)

Increased forces compared to conventional CD

Increased use and forces applied to residual ridge areas with increased resorption

Need relines in bilateral residual ridge resorption areas to provide load bearing areas of OD










Attachment breakage or fractures

(17%)

Improper loading, angulated and/or imbalance of engagements of attachments

Differential wear of attachment parts

Soft tissue support adequate for loading bearing areas of OD

Inadequate interocclusal distance

Pick up attachments after correction of imbalance and obtain parallel alignment of attachments and achieve simultaneous contacts of components

Treatment plan properly

Change attachment types that require less interocclusal distance

Broken AttachmentsBroken Attachments

Plastic bar clipPlastic bar clip– damaged or brokendamaged or broken

• cut along long axis with sharp knife and cut along long axis with sharp knife and remove.remove.

– MissingMissing• replace by inserting a new clip into denture replace by inserting a new clip into denture

base receptaclebase receptacle• if unavailable, contact Command Implant if unavailable, contact Command Implant

CoordinatorCoordinator


Metal bar clipMetal bar clip– damaged or broken (replacement clip available)damaged or broken (replacement clip available)

• remove the clip and perforate the denture base remove the clip and perforate the denture base carefully for intraoral pick up replacement.carefully for intraoral pick up replacement.

• Block out under the bar with wax, seat the denture Block out under the bar with wax, seat the denture and position a new clip through access in denture and position a new clip through access in denture base.base.

• Use autopolymerizing acrylic resin with “bead brush” Use autopolymerizing acrylic resin with “bead brush” technique to fill in access and connect clip to denture technique to fill in access and connect clip to denture base. Polish , disinfect and deliver.base. Polish , disinfect and deliver.

• Always confirm seating of denture after repair and Always confirm seating of denture after repair and evaluate occlusion.evaluate occlusion.


• Metal bar clipMetal bar clip– Damaged or broken (replacement clip not available)Damaged or broken (replacement clip not available)

• remove all remnants of the clip from the denture base.remove all remnants of the clip from the denture base.

• block out under the bar with waxblock out under the bar with wax

• reline the clip area of the denture with a resilient chair side reline reline the clip area of the denture with a resilient chair side reline material (viscogel).material (viscogel).

– Intact clip with no retentionIntact clip with no retention• carefully bend the leaves of the clip toward the bar with a thin carefully bend the leaves of the clip toward the bar with a thin

instrument.instrument.

• Reseat the denture to confirm increased retention.Reseat the denture to confirm increased retention.

• Recheck occlusion.Recheck occlusion.


• Stud attachmentsStud attachments– treatment is similar to clipstreatment is similar to clips

• tease out “O” ring with an explorer and replace as needed.tease out “O” ring with an explorer and replace as needed.

• Fractured housing can be treated like a clip replacement.Fractured housing can be treated like a clip replacement.



Abutment Screw loosening (7%)

Inadequate Preload forces applied to abutment screw with inadequate torque force

Confirm proper use of torque driver, new abutment screw insert for each case, repeat torque tightening 2X with torque driver to 35Ncm.

If cemented crown, consider drilling access screw hole and convert to screw retained instead of fabrication of new crown

Problems with Screw Loosening

1) Improper use of torque driver leading to inadequate “preload” force application

2) Stripped screw driver or screw head

3) Use of lab screws versus definitive screws

4) Material and surface used for fabrication of screws

5) Design of screws

6) Occlusal overload

7) Combination of any or all of the above



Adjacent natural tooth drifting and opens contacts

Viscoelastic nature of PDL with adjacent rigid fixation of dental implant


Modification of adjacent occlusion to natural dentitions to prevent distal or mesial shifting of forces when partial edentulous space is present



Improper implant placement of implants to support desired prosthetic goals

Improper treatment planning

Surgery conducted without prosthetic goals

Improper or lack of use of surgical guides

Customized or angulated abutments

Screw retained prosthesis with access holes to accommodate off angles

Removal of implants and start again

Treatment Options when presented with minimal Interocclusal Distance

1) Increase vertical dimension of occlusion for restorative convenience.

2) Extract teeth involved that violated the interocclusal distance and replace accordingly.

3) Orthodontic intrusion of opposing teeth involved.

4) Coronoplasty, crown preparations, prophylactic endodontic therapy, periodontal crown lengthening options to restore teeth involved.

Treatment Options when presented with minimal Interocclusal Distance

5) Prior to surgical placement of implants, perform alveoloplasty of residual ridge to increase interocclusal distance.

6) Prosthetic design: screw retain as opposed to cement retain to implant level.

7) Restorative material: metal occlusal as opposed to porcelain fused to metal.

Lack of Inter Occlusal Clearance: Treatment Options

• 1) Coronal adjustment of opposing arch or prophylactic endodontic therapy, crown lengthening and crowns to opposing arch.

• 2) Alveloplasty prior to implant placement with deeper surgical implant placement.

• 3) Prosthetically compensate with screw retained and metal occlusal to decrease required restorative clearance.



Substructure misfits

Impression copings not seated at final impression

Inaccurate final impression material unable to hold impression coping stable

Lab process errors during waxing, investing and casting

Verify with radiograph of confirmed seating

Use Medium body around impression coping or splinting with pattern resin

Use experienced labs

Iatrogenic / Prosthetic

Need for Provisional Restorations:– Positional stability– Occlusal function– Easily cleaned and maintenance of oral

hygiene– Nonimpinging soft tissues– Strength and retention– Esthetics

Iatrogenic / Prosthetic


Early soft tissue dehiscence

Micro movement pressure to graft site

Incorrect design of provisional restoration

Apical pressure application to healing site

-Choose proper design of provisional restoration (fixed or removable) with proper relief over surgical site

- No provisional restoration

Removable Provisional1) Acrylic RPD (flipper)

a) Need proper design for occlusal stops.

b) Adequate relief under pontic site or above grafted site upon occlusal pressure.

c) Permanent soft tissue reline material as occlusal force buffer.

Removable Provisional

2) Essix appliance (Acrylic removable overlay prosthesis)

a) Need proper design for occlusal stops.



Removable Provisional

3) Hawley orthodontic retainer appliance:

a) Need proper design of occlusal stops.



Consequences of Peri-Implantitis

• 1) May lead to eventual implant loss.

• 2) Soft tissue exudates, abscess or infection localized to peri-implant locations.

• 3) Guarded prognosis and continuous soft tissue maintenance requirement for peri- implant soft tissues.

• 4) Possible source of irritation and discomfort to patient.

Possible Etiologies of Peri-Implantitis

• 1) Location of Microgap

• 2) Implant Thread Design

• 3) Surgical Trauma

• 4) Quality of bone

• 5) Occlusal Forces

• 6) Bacterial contamination

• 7) Biologic width consideration

• 8) Cement trap contamination

• 9) Combination of any / or all of above

Peri-Implantitis-Definitions• Defined as an inflammatory process

affecting the tissues around an osseointegrated implant in function, resulting in loss of supporting bone.

(Albrektsson & Isidor 1994)

• Plaque-induced progressive marginal bone loss observed on radiographs with clinical signs of infection of the peri-implant soft tissues.

(Cochrane Database of Systematic Reviews 2006)

Peri-implant Mucositis-Definitions

• Defined as reversible inflammatory changes of the peri-implant soft tissues without any bone loss.

(Albrektsson & Isidor 1994)

Prevalence Rates

• Peri-implant Mucositis: 8-44%

• Peri-Implantitis: 1-19%

Cement retainedCement retained1) Ideal aesthetics.2) Questionable retrievability.3) Retention require conventional fixed

prosthodontic principles of CHS of >7.0 mm.4) Ideal Implant placement to support prosthesis

with use of straight or angulated abutments.5) Ideal Occlusion or support over axially loaded

ceramics.6) Less requirements for passivity or lab costs.7) Removal of cement subgingival may be

compromised.8) Depth of implant level placement should allow

ease of cement clean up.

Cement Problems

• Subgingival cement left after cementation acting as a foreign body reaction causing pathologic bony and soft tissue reactions.

Dr. Mark Lin’s Cementation Technique

1) Paint and coat OUTSIDE crown margins with Vaseline. Confirm lab provided 2 layers of die spacers on implant abutment or scanning of abutments.

2) Light coat of cement of choice into implant crown restoration.

3) Pump restoration “Up and Down” motion to release hydraulic pressure build in to allow thinning of cement layer.

4) Removal after setting with curettes and floss.5) Soft tissue release may be required to confirm

total removal of excess cement.6) Verification of seating of abutment and crown to

implant platform level and cement removal.

Screw retainedScrew retained• 1) Compromised aesthetics.• 2) Reliable retrievability. (Multiple or full mouth

reconstructions.)• 3) Retention achieved with minimal CHS of < 7.0 mm

using screw retention preload principles.• 4) Accommodate compromised Implant placement to

support prosthesis with use of custom or angulated abutments.

• 5) Compromised Occlusion or support over axially loaded compromised integrity ceramics.

• 6) More requirements for passivity or lab costs.• 7) No cement clean up considerations.• 8) Deep implant level placements.• 9) Transitional provisionals with multiple units.






5) Design of screws



Oral HygieneOral Hygiene

• calculus build up can cause calculus build up can cause areas of soft tissue areas of soft tissue inflammation.inflammation.• may result in progressive may result in progressive bone loss if left untreated.bone loss if left untreated.

TreatmentTreatment

• remove prostheses, check remove prostheses, check implants for mobility, implants for mobility, retorque abutments.retorque abutments.• perform maintenance perform maintenance cleaning on prosthesis and cleaning on prosthesis and abutments.abutments.• reinsert prosthesis with new reinsert prosthesis with new screws, give oral hygiene screws, give oral hygiene instructions.instructions.

Maintenance and RecallMaintenance and Recall• AnnuallyAnnually

– periapical radiographs should be taken to monitor the crestal bone levels. (crestal bone periapical radiographs should be taken to monitor the crestal bone levels. (crestal bone can be at the level of the first thread in one year with 0.1mm continued loss to can be at the level of the first thread in one year with 0.1mm continued loss to approximately 1. 5 mm total bone loss)approximately 1. 5 mm total bone loss)

– remove and reinsert screw retained implant prostheses every 2 years unless indicated remove and reinsert screw retained implant prostheses every 2 years unless indicated otherwise.otherwise.

• Replace prosthesis with new retaining screws if removed.Replace prosthesis with new retaining screws if removed.

– Cemented restorations are usually permanent (nonretrievable).Cemented restorations are usually permanent (nonretrievable).– Recall focusRecall focus

• OcclusionOcclusion - verify there are no excursive contacts. Should not hold shimstock. Better to be out - verify there are no excursive contacts. Should not hold shimstock. Better to be out of occlusionof occlusion

• Oral hygieneOral hygiene - same requirements as for natural teeth. - same requirements as for natural teeth.• Soft tissue healthSoft tissue health - periodontal probing for evidence of disease. - periodontal probing for evidence of disease.• Screw joint torqueScrew joint torque - check for loosened screws (most common problem). - check for loosened screws (most common problem).• Integrity of attachmentsIntegrity of attachments - applies to overdenture / overpartials. - applies to overdenture / overpartials.• Stability of implantsStability of implants - must - must be stable (non mobile) to be successful be stable (non mobile) to be successful

Maintenance and RecallMaintenance and Recall• Screw retained prosthesisScrew retained prosthesis

– Remove prosthetic retention screwsRemove prosthetic retention screws• Screw access holes are usually sealed with a layer of cotton pellet, silicone plug Screw access holes are usually sealed with a layer of cotton pellet, silicone plug

or gutta percha the acrylic or composite resin.or gutta percha the acrylic or composite resin.• Expose the screw by drilling carefully through the resin.Expose the screw by drilling carefully through the resin.• Remove the screw (slot or hex) with the appropriate screw driver.Remove the screw (slot or hex) with the appropriate screw driver.• Throat drapes are highly recommended.Throat drapes are highly recommended.

– Check for implant mobility and retorque abutments to 20 Ncm. (hand tighten Check for implant mobility and retorque abutments to 20 Ncm. (hand tighten as much as possible with finger abutment driver if no torque control device as much as possible with finger abutment driver if no torque control device is available)is available)

– Clean and polish abutments (Do not remove)Clean and polish abutments (Do not remove)– Reseat restoration using new gold retaining screws.Reseat restoration using new gold retaining screws.

• Tighten screws as if doing nuts on the lugs of an automobile - place all screws Tighten screws as if doing nuts on the lugs of an automobile - place all screws back with minimal torque. Then work back and forth across the arch until all are back with minimal torque. Then work back and forth across the arch until all are tightened to 10 Ncm. (hand torque with appropriate hand screw driver if no tightened to 10 Ncm. (hand torque with appropriate hand screw driver if no torque controller is available)torque controller is available)

Maintenance and RecallMaintenance and Recall• Screw retained prosthesis (cont.)Screw retained prosthesis (cont.)

– Temporary reinsertionTemporary reinsertion• fill access holes with small cotton pellet and polyvinylsiloxane fill access holes with small cotton pellet and polyvinylsiloxane

impression material or putty.impression material or putty.

– Long-term reinsertionLong-term reinsertion• fill access hole with small cotton pellet over the head of the screw, fill access hole with small cotton pellet over the head of the screw,

followed by warm gutta percha and only 1-2 mm of acrylic or followed by warm gutta percha and only 1-2 mm of acrylic or composite resin.composite resin.

• Cemented restorationsCemented restorations– Single unitSingle unit

• usually nonretrievable and not removed for maintenance.usually nonretrievable and not removed for maintenance.

– Multiple unit (usually not indicated)Multiple unit (usually not indicated)• carefully tap off with crown remover, check for mobile implants and carefully tap off with crown remover, check for mobile implants and

retorque abutment screws.retorque abutment screws.• Replace restoration with provisional luting media, and recheck Replace restoration with provisional luting media, and recheck

occlusion.occlusion.

Hygiene AidsHygiene Aids

• Super - flossSuper - floss

• End tufted brushesEnd tufted brushes

• Proxy brushesProxy brushes

• Tarter control dentrificesTarter control dentrifices

• Mechanical instrumentsMechanical instruments

• PeridexPeridex










OD loss of retention or adjustments (30%)

Lack of Simultaneous contact engagements of attachments with differential wearing of component parts

Pick up attachments to be parallel

Use customized abutments to correct for unparallel implant placements




Resin acrylic veneer fracture of FPD (22%)

Unsupported substructure

Heavy occlusion for implant restoration

Steep cusp angles with lateral excursion forces

Substructure extension to support porcelain of less than 2.0 mm thickness


Shallow cusp angles with narrow occlusal table to avoid lateral forces




Inadequate interocclusal clearance for abutment, substructure and porcelain

Treatment plan options to manage interocclusal distance

Screw retain option

Metal occlusal

Osteoplasty prior to surgery to submerge implant platform level



OD relines required (19%)

Increased forces compared to conventional CD

Increased use and forces applied to residual ridge areas with increased resorption

Need relines in bilateral residual ridge resorption areas to provide load bearing areas of OD



Abutment Screw loosening (7%)

Inadequate Preload forces applied to abutment screw with inadequate torque force

Confirm proper use of torque driver, new abutment screw insert for each case, repeat torque tightening 2X with torque driver to 35Ncm.

If cemented crown, consider drilling access screw hole and convert to screw retained instead of fabrication of new crown






5) Design of screws





Adjacent natural tooth drifting and opens contacts

Viscoelastic nature of PDL with adjacent rigid fixation of dental implant


Modification of adjacent occlusion to natural dentitions to prevent distal or mesial shifting of forces when partial edentulous space is present



Improper implant placement of implants to support desired prosthetic goals

Improper treatment planning

Surgery conducted without prosthetic goals

Improper or lack of use of surgical guides

Customized or angulated abutments

Screw retained prosthesis with access holes to accommodate off angles

Removal of implants and start again



Substructure misfits

Impression copings not seated at final impression

Inaccurate final impression material unable to hold impression coping stable

Lab process errors during waxing, investing and casting

Verify with radiograph of confirmed seating

Use Medium body around impression coping or splinting with pattern resin

Use experienced labs



Acrylic Fractures Inadequate interocclusal distance from implant platform level to opposing cusp

Osteoplasty prior to implant placement to increase interocclusal distance

Consider different attachment options that require less interocclusal distance (Locator attachments)

Need >2.0 mm acrylic resin thickness over attachments for strength

Problems in the fieldProblems in the field

• Fractured/loosened screwsFractured/loosened screws

• Fixture lossFixture loss

• Poor oral hygienePoor oral hygiene

• Soft tissue reactionsSoft tissue reactions

• Broken attachmentsBroken attachments

• Fractured componentsFractured components

Problems in the fieldProblems in the field

• Fractured/loosened screwsFractured/loosened screws

• Fixture lossFixture loss

• Poor oral hygienePoor oral hygiene

• Soft tissue reactionsSoft tissue reactions

• Broken attachmentsBroken attachments

• Fractured componentsFractured components

Fractured or loosened screwsFractured or loosened screws• Usually results in localized inflammation, loose restorations and Usually results in localized inflammation, loose restorations and

discomfort.discomfort.– First suspicion when patient complains of discomfort or loose implant.First suspicion when patient complains of discomfort or loose implant.

• Prosthetic gold retaining screws have either a slot or hex head.Prosthetic gold retaining screws have either a slot or hex head.• Abutment screws require a hex abutment driver, large slot, hex or Abutment screws require a hex abutment driver, large slot, hex or

square driver.square driver.– Standard and conical (estheticone) abutments have a raised hex and require Standard and conical (estheticone) abutments have a raised hex and require

a wrench that fits over this hex.a wrench that fits over this hex.– All other abutment screws have the slot, hex or square depression inside the All other abutment screws have the slot, hex or square depression inside the

screw head.screw head.

• Loose single tooth abutments are Loose single tooth abutments are true emergenciestrue emergencies. Continued . Continued rotation can risk rounding the corners of the hex on the implant, rotation can risk rounding the corners of the hex on the implant, causing a loss in anti-rotation.causing a loss in anti-rotation.

Fixture lossFixture loss((Must differentiate between “failing” and Must differentiate between “failing” and

“failed”)“failed”) • Failing ImplantFailing Implant– Clinical signs:Clinical signs:

• progressive bone lossprogressive bone loss

• soft tissue pocketing and crestal bone losssoft tissue pocketing and crestal bone loss

• bleeding on probing with possible purulencebleeding on probing with possible purulence

• tenderness to percussion or torque forcestenderness to percussion or torque forces

– Causes:Causes:• overheating of boneoverheating of bone at the time of surgery or lack of initial at the time of surgery or lack of initial

stability.stability.

• Nonpassive superstructuresNonpassive superstructures

• inadequate screw joint closureinadequate screw joint closure

• functional overloadfunctional overload

• periodontal infection (peri-implantitis)periodontal infection (peri-implantitis)

Fixture lossFixture loss• Failing ImplantFailing Implant

– Treatment:Treatment:• Interim: remove prosthesis and abutmentsInterim: remove prosthesis and abutments

– irrigate with Peridexirrigate with Peridex– ultrasonic and disinfect all componentsultrasonic and disinfect all components– reinsert assuring proper screw torquereinsert assuring proper screw torque– recheck passive fit of framework and occlusionrecheck passive fit of framework and occlusion

• Failed ImplantFailed Implant– Clinical signs:Clinical signs:

• MobilityMobility– verify fixture mobility by removing any abutments and superstructures first.verify fixture mobility by removing any abutments and superstructures first.

• A “Dull” percussion sound has been associated with a failed implantA “Dull” percussion sound has been associated with a failed implant• Peri-implant radiolucency can be a radiographic findingPeri-implant radiolucency can be a radiographic finding

– often this is not evident on an X-rayoften this is not evident on an X-ray

Fixture lossFixture loss

• Failed ImplantFailed Implant– CausesCauses

• surgical compromise (overheating bone and initial lack of surgical compromise (overheating bone and initial lack of stability).stability).

• Nonpassive superstructures.Nonpassive superstructures.

• Inadequate screw joint closureInadequate screw joint closure

• Too rapid initial loadingToo rapid initial loading

• Functional overloadFunctional overload

• Periodontal infection (“peri-implantitis”)Periodontal infection (“peri-implantitis”)

– TreatmentTreatment• removal of the implantremoval of the implant

Iatrogenic / SurgicalComplication Etiology Solution

Block graft mobility during implant placement

Inadequate final Osteotomy preparation in width and/or length for desired implant size

As a result the implant insertion protocol separates the block graft from recipient site

Prepare Osteotomy site again to appropriate length prior to implant placement.

Consider use of bone tap drills prior to implant placement.

2-stage surgery with increase healing time

Clinical Protocol Related Block Grafts (Symphysis)

• Easier surgical access

• Larger donor graft size

• Potentially thicker volume of donor graft

• Mostly cortical with cancellous parts

• More demanding for wound closure

Clinical Protocol Related Block Grafts (Symphysis)Complication Etiology Solution

Damage or devitalization of adjacent roots

Not paying attention to surgical safety zone

Superior aspect of bone harvest must be at least 5.0 mm away from root apex of mandibular incisors

May require root canal therapies to devitalized roots of mandibular anterior dentition

Surgical zone of safety to be 5.0 mm away from roots, mental foramen, protuberantia mentalis / inferior border of mandible

Clinical Protocol Related Block Grafts (Symphysis)Complication Etiology Solution

Disturbed changes to neurosensory perception or numb teeth during healing

Incidence rate of 29%

Altered sensation of mucosa or facial aspect of the lip or chin area

Harvest of graft resulted in disturbance of the neurovascular innervations to localized area

Reassure patients that disturbance is transitional and should return within 3-6 months post operatively

Clinical Protocol Related Block Grafts (Ramus)

• Difficult surgical access, especially inferior cut

• Smaller donor graft size

• Potentially thinner volume of donor graft

• Mostly cortical with few cancellous parts

• Easy wound closure



Damage to inferior alveolar nerve

Height of approximately 11 mm with width of approximately 14 mm

Inferior and medial cut too deep and violation of neurovascular bundle of the IAN

Prevention and knowing the anatomical boundaries

Reassure patient that disturbance is transitional and should gradually return within 3-6 months



Inadequate donor size harvest, too thin or too small

Difficulty of surgical access

Impaired visual access to inferior cut

Poor patient selection for Ramus harvest

Soft tissue incision and reflection to access desired size of graft required

Use of additional site to complete desired size of graft


Block graft mobility during implant placement

Insufficient healing time

Lack of initial block stability

Dead space too large or granulation tissue interposed between donor and recipient site

Micro movement of graft during healing from prosthesis loading

If graft appears vital: remove it, revive the recipient site, reposition graft and reaffix with micro screws.

Wait at least 6 months of healing with no loading.

If graft appears Non vital:

Remove it, clean recipient site, consider another grafting procedure.

Bilateral Sinus Grafting


Small Perforation

(>5 mm) of the sinus Schneiderian membrane

incidence rate of

10-35%

Membrane is too thin specific to the patient

Membrane separation too rapid or wrong instrumentation

Presence of mucoid cyst

Presence of bony septae

Continue to separate around the small perforation to collapse and fold itself, then place a resorbable collagen membrane patch to close the breach integrity of membrane.


Large Perforation of the sinus membrane

Membrane is too thin specific to the patient

Membrane separation too rapid or wrong instrumentation

Presence of mucoid cyst or Presence of bony septum

Window opening with carbide instead of diamond burs

-Continue to separate around the large perforation to collapse itself, then place a slow resorbable membrane patch to close the breach integrity of membrane.

Attempt to suture membrane

-Abort procedure and reattempt entry after 6-12 months of healing.

During the Procedure• Window Separation• Haemorrhage• Pus• Serous Fluid• Difficulties in Sinus Lining Elevation

Difficulties in Window Separation

• Cut not through Bone

• Lower Cut below Floor of Sinus

• Cut too far Anterior

• Presence of Buttress

• Laceration of Lining

Difficulties in Lining Elevation

• Buttresses

• Undulations over Roots

• Peduncles over Roots

• Visibility and Access

• Sinus Lining Tears

Cause of Lining Perforation

• During Periosteal Elevation• During Window Preparation• Inadequate Instruments• Buttresses

• Layering

• Suturing

• Abort

Lining Perforation Management

When Tear Occurs

continue Elevation away from Tear

Suturing Tears• Do NOT attempt to Suture Thin Fragile Linings

• Larger Tears will occur

Immediately Post-operative

• Bruising • Haemorrhage• Swelling• Pain• Suture Line Opening• Infection

Delayed Post-Operative

• Pain

• Infection and Swelling

• Acute Sinusitis

• Chronic Sinusitis

• Oral-Antral Fistula

During Implant Placement

• Pus

• Sterile Serous Fluid

• Non-conversion of Graft

• Sinus Lining Perforation

Late Complications• Infection

• Loss of Graft

• Bone Loss around Implants

• Loss of Implants

Causes of Complications

• Pre-existing Infection

• Lining Perforation

• Surgical Field Contamination

• Graft Non-conversion

• Patient Non-compliance

Patient Non-compliance

• Smoking

• Drugs

• Alcohol

• Poor Oral Hygiene

• Self Abuse

Surgical Field Contamination

• Poor Surgical Technique

• Contaminated Graft Material

• Contaminated Implants

Clinical Protocol Related Sinus Augmentations


Sinusitis Infection

Perforation of the sinus membrane

Prevention of tear in sinus membrane

Antibiotic Prophylaxis

Topical decongestants

Avoidance of any action that creates +ve or –ve sinus pressure.

Cessation of nose blowing and sneezing with open mouth


Early soft tissue dehiscence, flap necrosis or premature incision line suture opening

Suturing under tension

Smoking habits

Prosthesis loading

Traumatic surgery

Infection

Insufficient vascularization

-Suturing without tension

- by oblique release cuts or horizontal scoring and blunt dissection of periosteum inferior to mucogingival junction prior to suturing

Iatrogenic / Surgical


Early soft tissue dehiscence, flap necrosis or premature suture opening

Sharp edges to block bone graft or material causing dehiscence over thin soft tissues

-Suturing without tension

-Contour of block grafts to ensure smooth, rounded sides

-Consider connective tissue grafting prior or in conjunction to block graft


Early soft tissue dehiscence and flap necrosis


Smoking habits

Prosthesis loading

Traumatic surgery

Infection

Insufficient vascularization


Sharp edges to block bone graft or material causing dehiscence over thin soft tissues

-Do not try to suture again

-Rx: antibiotics, Chlorhexidine rinse

-Induce marginal bleeding for healing by granulation tissue formation and secondary healing

Iatrogenic / Surgical


Early soft tissue dehiscence, flap necrosis with membrane exposure

Suturing with tension

Smoking habits

Prosthesis loading

-Do not try to suture again

-Rx: antibiotics, Chlorhexidine rinse

-Induce marginal bleeding for healing by granulation tissue formation

-If infected, remove membrane with no replacement and expect partial loss of graft

Clinical Protocol RelatedSoft Tissue Grafts


Incomplete root coverage with Free Gingival Grafts

Improper classification of marginal tissue recessions

Inadequate root planing

Failure to treat the planed root with citric acid

Inadequate size of interdental papillae

Improperly prepared

donor tissue

Referral to Periodontist

Take additional C.E. courses with Drs. Pat Allen and Michael Pikos




Inadequate graft size

Inadequate graft thickness

Dehydration of graft

Inadequate adaptation of graft to root and remaining periosteal bed

Failure to stabilize the graft





Excess or prolonged pressure in coaptation of sutured graft

Reduction of inflammation prior to grafting

Trauma to graft during initial healing

Excessive smoking


Complications In Tissue Engineering

Host / Patient Related

Operator / Surgeon Related

Clinical Protocol Related

Medical Status


Smoking Effects

Iatrogenic

Surgical

Block Grafts

Sinus Augmentations

ProstheticSoft Tissue

Grafts

Advantages of Immediate Loading

• Immediate patient rehabilitation with instant gratification by patients

• Support and contours marginal soft tissues in esthetic zones

• Stimulation of bone regeneration with progressive loading protocol

• Decreased clinical interventions and appointments• Decreased treatment time / increase profit margin

Disadvantages of Immediate Loading

• Increased cost due to provisional fabrications

• Potential higher failure rate if inappropriately applied

• Rely on patient cooperation and compliance for success

• Need back up plan for provisional options

Indications to Immediate loading

• Primary surgical implant stability of >35 Ncm

• Lower anterior zones with splinting

• Patient driven for esthetic zones

• Aid in soft tissue contouring during healing phase

• Compliance of soft diet by patient during healing

Contraindications to Immediate loading

• Inadequate surgical initial stability of < 35 Ncm

• Need for bone grafting to implant recipient site

• Smokers

• Periodontal disease

• Poor prosthetic occlusal control of biomechanics

• Poor patient compliance and cooperation

Indications for Flapless Surgery

1) Confirmed 3 dimensional anatomical bony recipient site for desired implant diameter, length and angulations.

2) Abundant keratinized attached soft tissue adjacent the buccal aspect of implant recipient site.

3) Adjustment to depth of drilling length with soft tissue thickness accounted during osteotomies.

Advantages for Flapless Surgery

1) Less discomfort and morbidity for patients

2) Minimal to no swelling or bruising after surgical procedure

3) No suturing or removal of sutures post surgical appointment

Disadvantages for Flapless Surgery

1) Blinded procedure without flap release

2) Cannot visualize, identify and protect important anatomical landmarks

3) Risk of bone fenestration and dehiscence not identified

4) Risk of perforations of bone and incorrect implant alignment

5) Experienced surgeons to attempt

Complication Management

1) Plan

2) Prepare

3) Prevent

Dr. Mark Lin’s Contact Information

• E-Mail address:

[email protected]

• Office Number:416-221-8828

• Personal Cellular number:416-991-8828

mailto:[email protected]

Documents

Prevention and Management Of Complications In Implant Dentistry