Episode 8: Dental Implant Failure and Patient Risk Assessment

dental implant failure

In episode 8 of the Dental Digest Podcast, Dr. Don Curtis discusses dental implant failure and patient risk assessment.

Dr. Curtis’s study gathered information from literature as well as expert opinions to create a risk assessment for patients wanting implants. The Delphi process was used to bring together experts at a consensus conference, where complicated clinical questions were posed and debated. The various experts were asked about risk factors for implant failure, and then these factors were collectively ranked from most important to least important. 

One should consider patient expectation versus reality. According to Dr. Curtis, 70% of patients expect implants to last a lifetime. In reality, 20% of patients will have implantitis. The dentist should make patients aware of their risks before the implants are ever placed.

Dentists are very familiar with certain risk factors for implant success such as diabetes and smoking. It’s important to ask how much the patient smokes and how controlled is the diabetes, instead of simple yes/no questions.

Factors that lead to dental implant failure

There are less obvious risk factors to consider when planning implants such as bruxism and cement retained implants.

Bruxism has several indirect effects on the implant system. For example, bruxing initiates corrosion on the implant body causing titanium particles to sink into the sulcus and aggravate bone loss. If a patient does brux and wants implants, Dr. Curtis advocates looking at wear facets on teeth as this is the strongest predictor of bruxing forces. As well, clinicians should evaluate all considerations such as strong masseter muscles, mandibular plane angle, and patient history (is the patient a nighttime grinder or only when stressed). 

What are the options for a bruxer who wants implants? The clinician could splint several implants, but most importantly the patient should be encouraged to wear a nightguard. Also, screw retained implant crowns are better because the dentist can retrieve the screw and remove the crown much easier if something were to break. 

Regarding cement retained implant crowns, Dr. Curtis states that dentists are really bad at leaving behind cement, even with our best efforts. Years after cement is left around an implant, clinicians will see bone loss and inflammation because it is a foreign body and some cements can be cytotoxic. A situation where a cement retained implant crown may be indicated is a thin alveolar ridge in the maxillary anterior where the surgeon elects not to bone graft. Generally speaking, plan to use screw retained implant crowns whenever possible.

Absolute contraindications in placing implants include severe periodontal disease and head & neck radiation.

Once the implant has integrated, how much do the risk factors matter? We don’t know. We do know that at the time of implant placement, controlling the big risk factors (smoking and diabetes) is critical! 

How do plaque levels contribute to peri-implantitis? Patients with excessive plaque should be warned that this could lead to problems around the implant. It is much harder to stop the inflammatory process around implants than around natural teeth. Be diligent on recalls and cleanings to control plaque levels. 

Can dentists use the information from this study as a guideline? It’s a good process that is in place so far, but it still needs to be refined with more studies and data. At the moment, the risk assessment questionnaire created from the study is a really good place to start.

What are some big conclusions from the study? 1) Dentistry does not look at risk assessment very well. 2) Implants are more vulnerable than teeth and should not be treated like a tooth. 3) Using some sort of risk assessment questionnaire for patients will not turn them away from implants. In fact, it helps them feel more well informed.   

What is important in the patient history to know about in order to prevent dental implant failure? Smoking, diabetes, a failed implant, antiresorptive agents, antidepressants (SSRI’s), and proton pump inhibitors. 

There are some factors that haven’t shown much correlation with implant failure. They are: alcoholism, hepatitis, xerostomia (unless caused by radiation), low patient motivation, and cardiovascular disease. In other words, clinicians don’t need to consider these factors very “risky” when planning an implant.  

Website for the patient risk assessment: http://www.mydentalrisk.com/   Patients can fill this out beforehand or chairside with the dentist.

The full study is titled: Patient-Centered Risk Assessment in Implant Treatment Planning. https://pubmed.ncbi.nlm.nih.gov/30716143/

To listen to the episode, click here.

Hannah Wilken

This summary was written by the very talented Hannah Wilken.

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