What are the general guidelines for using medical implants, such as orthopedic or dental implants, in patients?

General Guidelines for Medical Implants

Medical implants, whether orthopedic or dental, have very few absolute contraindications, and the degree of systemic disease control is far more important than the nature of the disorder itself. 1

Patient Selection and Contraindications

Absolute Contraindications

• Active, uncontrolled systemic infection 1
• Severe immunocompromise that cannot be stabilized 2
• ASA classification IV or higher (unless exceptional circumstances exist) 3
• Medical conditions that immediately jeopardize life or significantly limit lifespan 2
• Cognitive decline preventing informed consent or post-operative care compliance 2

Relative Contraindications Requiring Optimization

• Uncontrolled diabetes (hyperglycemia >160 mg/dL should be stabilized before proceeding) 4
• Active periodontal disease (must be treated before dental implant placement) 4
• Poor oral hygiene (must be corrected and maintained) 4
• Smoking (significantly increases implant failure risk) 2
• History of radiation therapy to the implant site 2
• Bruxism (increases dental implant failure risk) 2

Special Population: Renal Failure Patients on Dialysis

Pre-Operative Evaluation

• Obtain CBCT imaging to assess bone volume and quality 4
• Check serum calcium, phosphate, PTH, alkaline phosphatase, and vitamin D levels to evaluate bone metabolism 4
• Eliminate all oral infections before implant surgery, including periodontal disease and dental caries 4
• Assess residual bone adequacy (hemodialysis patients typically have sufficient alveolar bone despite some abnormalities) 4

Surgical Timing

• Schedule implant surgery on the first day after hemodialysis when circulating toxins are eliminated, intravascular volume is high, and heparin metabolism is optimal 4
• Alternatively, schedule for the second day after hemodialysis for patients receiving three-times-weekly dialysis 4

Antibiotic Prophylaxis for Dialysis Patients

• Administer 2 g amoxicillin orally 1 hour before surgery for non-penicillin-allergic patients 4
• For penicillin allergy: give 600 mg clindamycin orally 1 hour before surgery 4
• Avoid aminoglycosides and tetracyclines due to nephrotoxicity 4
• Avoid nitrofurantoin (produces toxic metabolites causing peripheral neuritis) 4
• Adjust antibiotic dosing based on residual kidney function in consultation with the patient's nephrologist 4

Anesthesia Considerations for Dialysis Patients

• Use lidocaine or mepivacaine safely 4
• Reduce epinephrine concentration due to hypertension risk (use 4% articaine with 1:100,000 epinephrine, maximum 7 mg/kg) 4
• Monitor blood pressure throughout the procedure 4

Antibiotic Prophylaxis for Orthopedic Implant Patients

Dental Procedures

• Discontinue routine prophylactic antibiotics for patients with hip and knee prosthetic joints undergoing dental procedures 4
• This recommendation is based on a well-conducted case-control study showing no association between dental procedures and prosthetic joint infection, regardless of antibiotic prophylaxis 4
• Maintain appropriate oral hygiene in all orthopedic implant patients 4

Non-Urologic Surgery

• Do not screen for or treat asymptomatic bacteriuria in patients undergoing non-urologic surgery with orthopedic implants, beyond standard perioperative prophylaxis 4
• Postoperative orthopedic implant infections had different pathogens than preoperative urine isolates, suggesting sources other than urine 4

Dental Implant-Specific Guidelines

Timing of Implant Placement Post-Extraction

• Type I (Immediate placement): For intact facial bone wall >1 mm thick, sufficient apical bone, thick soft tissue biotype, no acute infection 4
• Type II (Early placement with soft tissue healing, 4-8 weeks): Most common approach (>80% of cases) for thin or damaged facial bone wall requiring contour augmentation 4
• Type III (Early placement with partial bone healing, 12-16 weeks): For extended periapical bone lesions 4
• Type IV (Late placement, ≥6 months): For adolescents <20 years or extended treatment delays 4

Sinus Augmentation Procedures

• Use L-PRF membranes to cover the Schneiderian membrane with at least two double-folded layers where implant apices will be placed 4
• Create perforations in alveolar bone to increase blood supply when insufficient 4
• Instruct patients to avoid nose blowing for 1 week and avoid flying, diving, forceful sneezing, or wind instruments for 6 weeks 4
• Prescribe painkillers and nasal spray, consider corticosteroids for 3 days to prevent Schneiderian membrane swelling 4
• Antibiotics are not always required when using only autologous L-PRF due to its antibacterial properties 4
• Consider systemic antibiotics when bone substitutes are used 4

Short Implants vs. Standard-Length Implants

• Short implants (≤6 mm) show 96% survival rate compared to 98% for longer implants over 1-5 years 4
• Extra-short implants (≤6 mm) have 5.19% cumulative failure rate over 5 years, similar to conventional implants 4
• Short implants avoid major bone augmentation, reducing invasiveness, morbidity, treatment time, and cost 4

Perioperative Management

Pre-Operative Requirements

• Obtain informed consent explaining treatment and possible complications 4
• Perform oral antisepsis with 0.12%-0.20% chlorhexidine mouthwash for 3 minutes before surgery 4
• Consider computer-guided flapless surgery for complex cases to shorten operation time, lower bleeding risk, and decrease post-surgical discomfort 4

Post-Operative Care

• Include all implant patients in regular periodontal maintenance programs to prevent peri-implant disease 4
• Monitor for clinical improvement within 48-72 hours after any intervention 5

Common Pitfalls to Avoid

• Do not proceed with dental implants when blood glucose >160 mg/dL 4
• Do not ignore active periodontal disease before implant placement 4
• Do not use nephrotoxic antibiotics in renal failure patients 4
• Do not routinely prescribe prophylactic antibiotics for orthopedic implant patients undergoing dental procedures 4
• Do not screen for asymptomatic bacteriuria before non-urologic orthopedic surgery 4