Learning to Fail: Defining Failure


It’s not if, but when.

Everyone who works with dental implants will find themselves here at some point. The implant site shows some ominous signs–bone loss, bleeding on probing, exudate, or maybe even mobility (gasp!!)…and it is unclear how to proceed.  

Looks borderline. Is it failed? Or still ok?


This series of posts will be dedicated to learning to manage implant failures and to use them as a way to improve yourself as a dental implantologist.

Rather than sweeping them under the rug, let’s value them as rare and treasured learning opportunities.

Necessary Conditions for Success

Let’s take a quick, high-level view at some of the conditions that we need for our implants to thrive. (We’ll take a closer look later)

First, when the implant is placed into the preparation, it should be surrounded by bone and completely immobilized.  (Remember we previously discussed what insertion torque is best)

Second, a blood clot must form between the implant surface and the preparation.

Third, the patient’s body develops vasculature in the site and sends in growth factors and osteoprogenitor cells. This allows bone to gradually be deposited on the implant surface.

Finally, the bone around the implants constantly remodels depending on its surrounding conditions. In a healthy implant, the fixture and prosthesis allow for a favorable homeostasis between the implant and bone.

Why You Will Fail

There are several things that can prevent you from achieving this homeostasis. We’ll discuss them at length in the upcoming articles in this series, but here is a quick list:

  • Surgical blunders
  • Compromised healing
  • Infection
  • Occlusal Trauma
  • Poor bone quality or volume

Did my Implant Fail?

Implant outcomes come in all shapes and sizes. This goal of this introductory post is simply to establish a framework to help categorize your implant outcomes.

 Let’s look at this set of criteria that was established by the International Congress of Oral Implantologists to help us add some structure to our failures. 

They categorize implants into 4 broad categories: Success, Satisfactory survival, Compromised survival, and Failure. Here is a quick description reference for each category.

ICOI Classification

  • Success
    • No pain/tenderness on function
    • No mobility
    • <2mm of radiographic bone loss after placement
    • No Hx of pus
    • Patient and dentist satisfied with esthetic outcome
  • Satisfactory Survival
    • No pain on function
    • No mobility
    • 2-4mm of radiographic bone loss after placement
    • No Hx of pus
  • Compromised Survival
    • May be sensitive on function
    • No mobility
    • Radiographic bone loss >4mm (less than half of implant body)
    • Probing depth >7mm
    • May have Hx of exudate
  • Failure
    • Pain on function
    • Mobility
    • Radiographic bone loss > half the implant body
    • Uncontrolled exudate
    • No longer in the mouth

Compromised or Failure?

In the absence of mobility, many of us struggle (at least I do) with deciding if a suspicious implant falls into the “compromised survival” or “failed” category.

The answer is not always clear. Sometimes this “borderline” implant will be treatable, and others it will continue to go downhill. Some things to consider in this case are:

  • Are you able to resolve any exudate?
  • Is the bone loss occurring very quickly or gradually?
  • Can the restorative plan be altered to improve the overall outcome?
  • What are the patient’s preferences?

Remember, uncontrolled exudate classifies the implant as a failure and indicates removal based on the ICOI guidelines. The answers to the other questions can help you steer towards the right choice for your patient’s overall well-being.

Now that we have:

1) An idea of  what factors are playing a role in success v. failure, and

2) A simple classification system to guide us,

…we’re ready to start looking at some specifics, in the next post.

Do you have any  ‘borderline’ failures and are unsure of how to proceed?  I would love to hear about your case. By sharing your cases, we can all learn from each other’s experiences!

Coming up:

Subscribe to the blog (upper left on desktop, below on smartphone) to stay tuned for upcoming articles in “Learning to Fail.” We will cover:

  • treatment options for the compromised implant
  • risk factors you should memorize
  • clinical examples of some interesting failures
  • video interview on failure with leading implant surgeons



Misch CE, Perel ML, Wang HL, Sammartino G, Galindo-Moreno P, Trisi P, et al. Implant success, survival, and failure: The International Congress of Oral Implantologists Pisa Consensus Conference. Implant Dent 2008; 17:5-15.

Beumer J, Marunick M, Esposito S. Maxillofacial Rehabilitation. Hanover Park: Quintessence. 2011.

Froum, Stuart. Dental Implant Complications.: Etiology, Prevention, and Treatment. New Jersey: Wiley & Sons. 2016. Electronic copy.

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