What is the reason for the rejection of a dental implant?

Dental implants are the most effective and long-lasting solution to missing teeth. However, you may have heard about the possibility of rejection. Although it is very rare, as only 2% of patients seen in dental clinics with highly qualified staff suffer from it, it is possible even when using the best quality materials. That is why it is important to pay attention to the advice of specialists to avoid it.

What you need to know to ensure the success of dental implant treatment.

1. What are the symptoms of rejection?
2. What does rejection of a dental implant involve?
3. What are the causes of implant rejection?
4. Is it possible to replace the implant after rejection?
5. How can dental implant rejection be prevented?

1. What symptoms indicate that rejection may occur?

Although dental implant treatment has very positive results and, as we have said, only 2% of patients treated under optimal conditions experience rejection, it is important to know the signs that indicate that during the healing period (between the placement of the prosthesis and the placement of the final crown) something is going wrong. The problems that can appear are:

• Mobility of the prosthesis: during the period of healing and osseointegration the dental implant should not move. This is the clearest symptom.
• Appearance of discomfort and pain when pressing on the implant: it is not usual to feel persistent pain 72 hours after the prosthesis has been fitted.
• Inflammation and redness in the treated area: this indicates that an infection may have appeared and that the area has filled with pus.

So, if you experience these symptoms, it is key to make an appointment with the implantologist. However, some patients may unconsciously overlook these signs, or not notice them at all. In these cases, they may feel pain when they are scheduled for impressions to design the crown. At this point, the specialist can determine that there is a rejection of the implant by studying the area, but what exactly is it?

2. What does rejection of a dental implant involve?

We could say that the rejection of a dental implant is due to poor healing of the gum. Technically, the concept of rejection is not correct in dental implantology since the titanium screw placed is completely biocompatible with our organism and there is no immune reaction against the material, as happens in surgical processes with organ transplants where rejection can occur.

Therefore, the failure of a dental implant (the correct term to use in this situation) is possible and occurs, as we have said, during the healing period, after the titanium implant has been placed, which in optimal conditions can last approximately three months. If during this time the gum does not heal correctly, white tissue forms between the bone and the implant and can surround the prosthesis.

If this is the case, it will be impossible to load the crown on the implant, as it will not be supported. If healing fails, the specialist will have to remove the implant and proceed to clean the fibrous tissue in depth. In order to treat the problem and replace the prosthesis, it is essential to take into account the cause of the failure during the healing process of the implant.

3. What are the causes of implant rejection?

Although, as we have mentioned, the probability of rejection or failure is minimal, there are certain factors that can give rise to complications during the osseointegration or healing process, i.e. during the union between the dental implant and the patient’s natural bone.

• Smoking. Patients who smoke, especially those who smoke more than 10 cigarettes a day, are more likely to experience problems during osseointegration. The nicotine present in cigarettes slows down the healing process and can even promote infection of the area.
• Insufficient and inadequate oral hygiene. Both a lack of oral hygiene and the application of an inadequate and traumatic technique can lead to the accumulation of infection-causing bacteria that affect the healing process.
• Peri-implantitis. This is a peri-implant disease that could be considered equivalent to the appearance of periodontitis or pyorrhoea in the implanted area. It also has its origin in the accumulation of bacterial plaque that causes inflammation of the mucosa of the treated area and begins to destroy the bone supporting the implant.
• Diseases such as diabetes. Patients with systemic diseases such as diabetes have an increased risk of oral infections leading to implant rejection.
• Malpractice: poor treatment planning, an incorrectly designed prosthesis, poor quality dental implant material, or performing a surgical technique without taking into account the patient’s characteristics can also lead to dental implant rejection.

Although implant failure does not always have to occur in these situations, especially if they have been carried out in approved dental centres, with experience and using quality technologies and materials, there is a minimum probability of it happening. Hence the importance of following the specialist’s recommendations to ensure that the healing process is completed successfully and complications are avoided:

4. How can dental implant rejection be prevented?

As we have already mentioned, it is essential to follow the indications of the implantologist in charge of the particular case. Each intervention in implantology must be personalised. The specialist must study the patient’s clinical history and determine the best treatment plan to guarantee success.

The approach will be different depending on the particularities and needs of each patient, depending on the amount of bone remaining, the previous oral health despite the lack of a dental piece, the need for a complete oral rehabilitation… It is therefore essential to follow the guidelines determined by the specialist, taking into account generic aspects such as:

• (Smoking patients should) eliminate or reduce tobacco consumption for two weeks prior to dental implant placement and while the implant and bone healing process lasts.
• Perform good oral hygiene at home following the specific recommendations that the specialist may prescribe. As we have already mentioned, insufficient hygiene and a traumatic technique are harmful. Therefore, be sure to use a soft-bristled toothbrush and interproximal brushes, or floss or dental floss to remove food debris between teeth. Clean your tongue and use an appropriate mouthwash.
• Keep all appointments with your dentist. Don’t skip scheduled check-ups, because if you miss the signs of rejection, only the specialist will be able to identify the potential problem early and prevent it.

5. So it is not possible to replace the implant after rejection?

Yes, it is possible to replace the implant. The specialist must remove the fibrous tissue that develops around the implant and treat the infection on a case-by-case basis. When oral health is guaranteed, it is possible to reinsert the implant and wait for it to heal again.