Dental Implant Failure
Dental Implant Failure
Dental implants placement is a complicated surgical procedure therefore implant failure is always a possibility. Several conditions can lead to dental implant failures. The success rate of dental implant treatments also depends on other factors such as position of replaced tooth, or pre-existing dental or general health conditions.
Success / failure rate of dental implants
Available studies indicate that surgical placement of standard root-form implants has a success rate of 90-95% in general.
Recent advances in dental implants related technology and materials have allowed experienced implant dentists to claim success rates over 98%.
Most of the dental implant problems occur during the first year after the surgical placement of the implant and usually before the placement of the abutment and the restoration.
Success rates of dental implants are usually measured over a 5 year period after placement. After the first year, implant failure rate is around 1% per year and in most cases due to improper aftercare and poor oral hygiene.
With proper care implants can last for a lifetime without any problems or need of maintenance (such as needed for bridges or dentures).
What is considered as dental implant failure?
Dental implants may fail for a number of reasons. The cause is often related to a failure in the osseointegration process. Dental implant failure is in most cases the result of the implant failing to bond (osseointegrate) properly with the jawbone. Failure is determined by the inability to achieve and maintain implant stability.
Inflammation in the bone surrounding the implant is a first indication of possible implant failure. Spinning or moving an implant around its vertical axis is a clear sign of implant failure. It is not unusual for a failed implant to simply fall out of its socket during chewing or talking. Technically a dental implant is considered to be a failure if it is lost, mobile or there is bone loss around it greater than 1.0 mm in the first year and greater than 0.2mm a year thereafter.
What to do / options after a dental implant failure
In case of a dental implant failure the dentist has to remove the implant (if it has not already fallen out), treat the cause of the failure and replace it with a new implant. The process may differ depending on the type of implant failure:
- implant breakage without jawbone damage - in this case the dentist can place the new implant immediately after removing the damaged one.
- implant infection or osseointegration problems
- medium bone loss - the dentist will leave the implant area to heal, after eliminating the cause of the initial implant failure. The new implant can be placed a few months later.
- severe bone loss - if an implant infection or other reason has caused severe bone loss, the implant dentist will have to perform first a bone grafting procedure, before attempting to replace the failed implant with a new one. If the implant is used to support a denture, the dentist may place a new implant in a slightly different but more suitable position to avoid bone grafting.
Dental implant failure rate by area of mouth
Different areas of the mouth have different dental implant failure rates due to their special characteristics. The placement of implant in the front parts of the lower jaw has to demonstrate the best success rate as high as 98-100%. Generally dental implants failure rate in any position of the lower jaw is smaller than that of the relative position of the upper jaw. This is explained from the fact that bone quantity and density is usually better in the lower jaw. Implants placed in the front part of the upper jaw show a failure rate of 5-10%.
The areas that have the higher implant failure rates 5-15% are these of the posterior (back) molar teeth, especially these of the upper jaw. Replacing back teeth with implants requires a much more difficult procedure that could challenge the dentist's training and experience. Additionally back teeth have to withstand more pressure during chewing which could negatively affect the proper bonding of implants to the jawbone.
Dental implant success is related to implant dentist's skill, quality and quantity of the jaw bone available at the surgical site, and also to the patient's oral hygiene.
Groups with increased risk of dental implant failures
Dental implant failures are statistically higher in some specific groups of patients. These include:
- Younger patients with jawbones not fully developed
- Patients with severe jawbone loss or low bone density
- Heavy smokers, drug or alcohol abusers
- Patients with chronic diseases like diabetes, hemophilia, or immune system deficiencies
- Patients who have had radiation therapy to the head/neck area
- People with bruxism problems