Exotic Encounters with Dental Implants!

Exotic Encounters: Dealing with complications
of inidentified dental implants

As the application of dental implants widens, we inevitably have to deal with an increasing amount of complications, sometimes with implants we have never encountered before! Are we prepared?

By Nikos Mattheos, Griffith University
Read the complete article in Australian Dental Journal

As the application of dental implants is increasing worldwide, so is also the number of technical and biological complications that general dental practitioners will be called to manage, while maintaining implant patients. In addition, the greater patient mobility encountered today combined with a growing trend of "dental implant tourism" will very often result in situations where the dentist is requested to deal with complications on implants placed elsewhere and which sometimes might be of an "exotic" system one cannot directly recognise. Such a situation can pose significant challenges to even experienced clinicians. The challenges are not only on the scientific field, but often include professional and ethical implications. A recently published case report discusses in detail strategies for the management of implant complications, in cases of unidentified implant systems. Critical factors in such situations would be the clinician's experience and special training, the correct radiographic technique, as well as access to the appropriate tools and devices.

Some critical steps:

1- Can we identify the implant system?

Prerequisite for every treatment is knowledge of the respective implant system and access to the appropriate tools. Even in the case of biological complications, where the treatment is not system-specific, removal of the reconstruction is a necessary first step in order to have direct access to the inflamed area .

Certain websites can be helpful inhelping identify the system. Sites such as what implant Is that , Osseosource and Whichimplant are equipped with a search engine that allows identification of implants through its radiographic characteristics. Such sites can help an experienced clinician, but in most cases contact with the doctor who placed the reconstruction if possible, appears to be the safest way.

2- Is this an implant system I can work with?

This can be broken down to many more questions. Do I have access to the tools needed to unscrew abutments and remove components? Is this system available in Australia so that I can easily order a new screw? Very often, especially in treatments done abroad, implant systems will be used that are not available or represented in Australia. You might be still able to order tools and components through the internet, but this might raise some important legal implications: Certain implant parts and components are sold as medical devices and as such they require a specific licencing procedure through Australia's Therapeutic Goods Administration. Unless a specific exemption has been granted, it is a criminal offence under the Therapeutic Goods Act 1989 to import into, supply in or export from Australia, a medical device that has not been entered onto the ARTG.

Often, we will be informed by the patient or the overseas dentist who restored the implants that the system used is "compatible" with company "X", with X implying a major company that is also represented in Australia. Using however components of company X on the "compatible" system is not covered by any warranty and there is little to ensure that we are not running risks for further problems in the future.

3- Why did the complication occur?

A critical issue is to identify the possible reasons for the complication. Implant complications, especially the technical ones do not occur "randomly". In most cases there is some hidden underlying problem, which unless we can identify, we run the risk of having the complication repeated in the future. For example, a loosening of an abutment screw might be attributed to several factors:

- Was the screw not tightened to the correct torque value?
- Was there a defect in the threads or the head of the screw?
- Was there any incompatibility between the implant and the screw threads?

If the underlying reason was any of the above, then replacing the missing screw with a new one and properly torque tightening will most likely solve the problem. But what if there was any tension in the metal framework due to incorrect fitness of the denture? In that case replacing the screw will only mask the problem for a while, until another loosening or fracture occurs, most likely to the same place.

4 - Can I prevent this complication from reoccuring?

To respond to this question one must have positively identified the cause of the complication, which in many cases might be far from obvious to routine examination.
For example, a simple abutment screw loosening might be due to defective screw or a inpropriate torque, but it could also be connected to wide range of other undelying factros such as inapropriate occlusal design, parafunctions, missfit and tension of the metal framework and more.

5 - How to conduct a radiographic examination on an implant?

It is of outmost importance to secure that the direction of the cone is absolutely parallel to the implant threads. Only this way one can evaluate the relation between all parts of the implant and the prosthetic reconstruction. In cases when multiple implants are placed (often with slightly different angles) there might be a need to take an individual radiograph for each of the placed implants, in order to examine all parts correctly.

A Case example:

A male patient, 55 years old, requested an emergency appointment. He mentions that 6 months ago he received an implant supported Fixed Partial Denture in the lower jaw during a trip abroad, with which he is in general satisfied. Unfortunately he recently realised that the right side feels slightly mobile

Upon examination, it becomes apparent that the abutment screw of the distal implant in the right side has fallen off . In addition, there is a whole "wall" of calculus underneath the hybrid denture, as access of the peri-implant area to oral hygiene is completely blocked by the reconstruction. This has resulted in an advanced mucositis, with severe bleeding at the lightest touch of the area underneath the denture.

Course of actions

The implant system used was not available in Australia. We could use a compatible screw from company "X", without the security that the problem will not reoccur. The most critical issue was that of the access to oral hygiene (Image 9). The patient already suffered from an extensive mucositis, which would most certainly turn into a peri-implantitis and could threaten the survival of the implants on the long term. The denture had to be unscrewed, calculus had to be removed, implant surfaces polished and the acrylic/metal framework trimmed in such a way that oral hygiene will be possible around the implants. Such intervention, although necessary, is by no means guaranteed to solve all of the problems, or at least to not create new ones, especially these of technical nature.

Removing the screws with a "compatible" screwdriver, replacing the missing screw with a "compatible" screw and trimming, thus weakening the prosthesis framework at key points, might predispose to further complications in the future. The decision on how to proceed should be carefully considered and the patient must be informed on the compromise and risks undertaken at any stage. Balancing the benefits from any possible intervention with the risks of future problems is not very easy. Patient informed consent is very important in such cases. Refusal to undertake further action could be also justified, on the basis that proceeding with an intervention might mean inheriting "sins" of the past from a treatment that was done in a non-optimal way.

Quick Guide:

What to do if you restore implants:

  • Design implant prosthesis so as to allow access for oral hygiene
  • Design the occlusion free of damaging interferences, while guiding occlusal forces apicaly
  • Ensure tension-free (passive) fitness of the bridge framework
  • Follow all manufacturer's instructions and scientific guidelines and document every step
  • Use an implant system you trust which is supported by good scientific evidence
  • Avoid using "compatible" prosthetic components, copies or components of questionable origin, even if they appear to be identical to the ones of the original system
  • Document your baseline: Give a plastic implant id-card to your patients with all related information and a baseline radiogr

What to do if an exotic encounter comes your way:

  • Can you identify the implant system?
  • Do you have access to original components and devices?
  • Can you identify the underlying reason that lead to the actual complication?
  • Can you correct it?
  • Can you prevent recurrence of the complication?

If the answer to any of the above is negative, consider carefully before you proceed with any intervention. In many cases the risks one undertakes outweigh the benefits. A referral to a specialist clinic is in most cases justified and might be a far more beneficial option on the long term.

Read the complete article at Australian Dental Journal here

Last modified: Wednesday, 27 June 2012, 06:40 AM