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Dental implants.
Indications, contraindications

author icon By Dr. George Ghidrai


Dental implants can successfully restore all forms of partial edentulism and complete edentulism. If there are no general or local contraindications, implant supported dentures are the method of choice in rehabilitating all types of toothless gaps.

Here are some situations when dental implants are strongly indicated :

  • 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.

    dental implant indication : single unit toothless gap

    single unit toothless gap

    dental implant supported crown

    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 and/or premolars) on one or both sides of the dental arch (Kennedy class 1 or Kennedy class 2).

    In these cases, traditional dental bridges (supported by natural teeth) are difficult to design because the back support tooth is missing. Removable partial dentures generally require the preparation of more teeth.

    Implant supported prostheses, although entailing a higher cost, are highly indicated in these clinical situations.

    dental implants indication : posterior teeth missing dental implants indication : posterior teeth missing dental implants indication : posterior teeth missing

  • Complete edentulism

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

    Implant supported prosthesis (either fixed or removable) allow to chew the food better, speak more clearly and they have a superior stability.

    overdenture supported by dental implants

    implant supported
    removable denture

    full denture

    full denture

  • Other situations when dental implants can be indicated

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


General contraindications

  1. Absolute contraindications

    Some serious 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-immunes diseases
    • Drug and alcohol dependency
    • Pregnancy


  • Children: not before the jaw bones have stopped growing (in general 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 times, 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). To ensure a good prognosis, a dental implant must be surrounded by healthy bone tissue.

    dental implant schematic

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

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

    dental implants temporary contraindication : maxillary sinus lowering

    lowering of the maxillary sinus

    Adjunctive surgical procedures have to be performed before the placement of dental implants. These procedures aim to increase the amount of bone, so more bone is available to support the implants.

  • 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 ; rarely occurs.

  • Poor oral hygiene.

  • Bruxism or involuntary grinding of the teeth.

Last review and update: February 2019

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