Dental implants.
Indications, contraindications

Last Updated: 10.01.2024

Author: George Ghidrai, MD  

When are dental implants strongly indicated?

Dental implants can successfully restore all forms of Edentulism: from Partial Edentulism, when one or more teeth are missing, to Complete Edentulism, when all teeth from a dental arch are missing.

In certain clinical situations, dental implants are strongly recommended over traditional restorations:

• Single unit toothless gap with healthy adjacent teeth

  When a single tooth is missing, an implant-supported crown will preserve the adjacent natural teeth by avoiding the need to prepare them.

  If the toothless gap is restored with a traditional dental bridge, both adjacent teeth will have to be prepared. This operation involves permanently removing parts of the teeth's original structure, including portions that might still be healthy and structurally sound.

  
  

  

  single unit toothless gap

  

  an implant-supported crown is the best treatment option

  
  
  

• Partial edentulism with the back (posterior) tooth missing

  These conditions imply the absence of several posterior teeth (molars, or molars and premolars) on one or both sides of the dental arch (Kennedy class 1 or Kennedy class 2 Partial Edentulism).

  What is Kennedy class 1 Partial Edentulism?

  • Back teeth on both sides of the dental arch are missing. The condition is caused by the early loss of posterior teeth on both sides of the dental arch.

    
  
  

  What is Kennedy class 2 Partial Edentulism?

  • Posterior teeth on just one side of the dental arch are missing. This condition results from the early loss of molars and premolars on one side of the dental arch.

    
  
  

  Traditional dental bridges (supported by natural teeth) are challenging to design in these cases because the back support tooth is missing. Removable partial dentures generally require the preparation of 4 to 6 teeth.

  Implant-supported restorations (either fixed or removable), although entailing a higher cost, are the best choice in these clinical situations.

  
  

  

  
  

• Complete edentulism

  When all teeth are missing, the only traditional solution available is a full removable denture.

  Implant-supported prostheses (either fixed or removable) allow you to chew food better, speak more clearly, and have superior stability.

  

  implant-supported
  removable denture

  

  full denture

  
  

• Other situations when dental implants are highly indicated

  • Patients who cannot tolerate a removable restoration (removable denture).
  • Patients with high aesthetic and functional demands.

General and Local Contraindications

Sometimes, some general or local conditions may prevent the placement of dental implants. Some of these conditions may be addressed before the implant's surgical placement, while others may make the overall placement inadvisable.

Let's review the general and local contraindications for dental implants.

General contraindications

1. Absolute contraindications

   Some severe general conditions make anesthesia, surgical procedures, and the overall placement inadvisable.

   • Heart diseases affecting the valves, recent infarcts, severe cardiac insufficiency, cardiomyopathy
   • Active cancer, certain bone diseases (osteomalacia, Paget's disease, brittle bones syndrome, etc.)
   • Certain immunological diseases, immunosuppressant treatments, clinical AIDS, awaiting an organ transplant
   • Certain mental diseases
   • Strongly irradiated jaw bones (radiotherapy treatment)
   • Treatments of osteoporosis or some cancers by bisphosphonates
   
   

2. Relative contraindications

   Other situations will be evaluated on a case-by-case basis. Most often, dental implants can only be placed (with the greatest caution) after some preliminary treatments.

   • Diabetes (particularly insulin-dependent)
   • Angina pectoris (angina)
   • Significant consumption of tobacco
   • Certain mental diseases
   • Certain auto-immune diseases
   • Drug and alcohol dependency
   • Pregnancy
   
   

Age

• Children: not before the jaw bones have stopped growing (generally 17-18 years).
• On the other hand, advanced age does not pose problems if the patient's general condition is good.

Local contraindications

Some conditions or physiological changes, usually inside the mouth cavity, may temporarily prevent the placement of dental implants. Most of the time, these conditions can be remedied before the implants are inserted in the jawbone.

• There is insufficient bone to support the implants, or bone structure is inadequate (due to some chronic infections or other conditions). Dental implants must be surrounded by healthy bone tissue to ensure a good prognosis.

  
  

  

  a dental implant must be surrounded
  by healthy bone tissue (with red)

• Important anatomical structures such as the maxillary sinus or the inferior alveolar nerve (located inside the mandible) have an abnormal position that can interfere with the dental implants.

  
  

  

  lowering of the maxillary sinus

  Adjunctive surgical procedures are crucial in these cases. These procedures aim to increase the amount of bone so that more bone is available to support the implants. We will discuss these procedures later in this book.

  
  

• Some local diseases of the oral mucosa or alveolar bone can temporarily prevent the placement of dental implants until the conditions are treated.

• Hypersensitivity or other allergic reactions; fortunately, they rarely occur.

• Poor oral hygiene.

• Bruxism or involuntary grinding of the teeth.