Dental Implant Rejection: How to Recognize the First Symptoms

Dental implants are the best solution for replacing missing teeth. Despite the high success rate of modern implants, many patients fear surgical procedures and the risk of implant rejection.
In this article, we discuss the rare cases of implant rejection, the early signs to watch for, and preventive measures.

Normal Process of Implant Integration

Dental implant integration, or osseointegration, is the process during which the implant fuses with the bone. During this process, hard tissues grow around the implant, ultimately leading to its integration into the jawbone. The process of osseointegration in dental implantation occurs in three stages:
• Initial stage. Lasts during the first month after implantation; at this time, spongy bone (immature bone tissue with low density) forms around the implant. Therefore, a permanent prosthesis is not recommended at this stage.
• Intermediate stage. This stage lasts 4–6 months. The spongy tissue is replaced by lamellar bone, which is secondary (strong and dense bone). It can withstand full chewing loads. At this stage, a crown, bridge, or full prosthesis can be placed.
• Final stage. This stage lasts up to 18 months. During this period, the implant completes its integration and stabilization. After 1.5 years, the risk of implant rejection is minimal.

Before the procedure, doctors pay close attention to the condition of the hard tissues. Dental implants can only be successful if there is sufficient bone density in the jaw to support the post. Patients with insufficient bone density (due to osteoporosis or other health problems) should not undergo dental implant surgery unless bone grafting is first performed. An experienced surgeon will be able to assess where a bone graft is needed and how many crowns the posts can support.

What is Implant Rejection?

Dental implant rejection is a pathological destructive process characterized by inflammation, resorption, and loss of already formed bone tissue surrounding the intraosseous part of the implant. Simply put, it is the body’s inability to accept or integrate a dental implant.

Rejection is rare. According to statistics, its prevalence ranges from 3% to 10%. The rejection rate of zirconia implants is even lower: from 0.5% to 2%.

An example of failed implantation is when the implant begins to be rejected and becomes mobile.

It is important to understand the difference between implant rejection and failed integration.
• When an implant fails to integrate, osseointegration does not occur at all. In other words, bone structures do not form around the implant. This problem becomes evident within the first few weeks or, at most, within a couple of months after implantation.
• During rejection, already formed hard tissues begin to inflame and atrophy. This process develops months or even years after surgery. It is always preceded by specific causes such as mucositis or peri-implantitis—diseases associated with inflammation of the tissues around dental implants.

How Does Implant Rejection Occur?

Implant rejection can be divided into three periods:
• Early: develops in the first days or weeks before the prosthesis is placed. The main causes of early rejection are surgical errors, severe systemic diseases in the patient, and non-compliance with postoperative instructions.
• Intermediate: develops within two years. It is most often associated with an improperly made prosthesis but can also be triggered by excessive chewing load and poor oral hygiene.
• Late: occurs two or more years after prosthesis placement. It may be caused by trauma, newly developed systemic diseases, or hormonal changes.

Even if implant rejection begins, it does not necessarily mean that the patient will lose it.

There are three degrees of mobility in implant rejection:
• Initial: the implant moves in two directions, with a movement amplitude not exceeding 0.5 mm;
• Moderate: the implant moves in three directions, with an amplitude of 0.5–1 mm;

• Severe: the amplitude of movement in three directions exceeds 1.5–2 mm.

Symptoms of Implant Rejection

In the first days after implantation, patients experience unpleasant symptoms related to the body’s reaction to surgical intervention. These symptoms are normal and gradually subside on their own within a week. However, in the case of implant rejection, similar symptoms may occur. It may be difficult for patients to distinguish between ordinary postoperative complications and the signs of implant rejection.

The following comparative table can help:

Late Symptoms of Dental Implant Rejection

Some cases of dental implant rejection appear within the first few months, while other problems may occur years later.
If you experience any of the symptoms below, it is important to consult your oral surgeon:
• Nerve or tissue damage: when the implant is placed too close to a nerve, you may feel tingling or numbness in your face, tongue, lips, and gums. This can affect your ability to eat and drink normally and should never be ignored.
• Foreign body rejection: sometimes the body rejects foreign objects such as organ transplants, prosthetics, or dental replacements. If you feel pain, inflammation, chills, or fever even years after implant surgery, your body may be rejecting the titanium implant.
• Facial trauma: trauma to the mouth or face can cause the loss of artificial teeth, just like natural ones. Contact your surgeon immediately after an injury to determine whether the prosthesis can be saved and to replace any recently lost teeth.

Causes of Implant Rejection

The main causes of implant rejection are inflammatory and infectious processes. As pathogenic microorganisms multiply, mucositis first develops – a purulent inflammation without bone resorption. If left untreated, it progresses to peri-implantitis – an infectious inflammation with exposure, damage, and resorption of hard tissues.
Advanced peri-implantitis involves purulent granulations, gum recession, and bone loss around the implant and neighboring teeth.

Rejection can occur due to oral diseases and systemic conditions that are relative or absolute contraindications to implantation, such as:
• bruxism
• malocclusion
• temporomandibular joint dysfunction
• allergic reaction to implant materials
• bone deficiency
• periodontitis
• osteoporosis
• hormonal changes
• facial trauma

Mucositis and peri-implantitis are triggered by many factors, which can be divided into two groups:
• doctor-related errors
• patient-related actions

Doctor-related causes:
• failure to follow aseptic and antiseptic protocols during surgery
• use of an implant of incorrect size or shape
• insufficient examination, planning, and preparation
• violation of the implantation protocol
• poorly manufactured prosthetic construction

Patient-related causes:
• smoking
• poor oral hygiene
• excessive chewing loads (e.g., nuts, chips, crackers, steaks, raw vegetables, hard fruits, or other solid foods in the first weeks after implantation)
• refusal to take prescribed medications in the postoperative period
• failure to follow restrictions during the first weeks (e.g., sports, swimming in open water, visiting spas or tanning salons)

Late Symptoms of Dental Implant Rejection

Some cases of dental implant rejection appear within the first few months, while other problems may occur years later.
If you experience any of the symptoms below, it is important to consult your oral surgeon:
• Nerve or tissue damage: when the implant is placed too close to a nerve, you may feel tingling or numbness in your face, tongue, lips, and gums. This can affect your ability to eat and drink normally and should never be ignored.
• Foreign body rejection: sometimes the body rejects foreign objects such as organ transplants, prosthetics, or dental replacements. If you feel pain, inflammation, chills, or fever even years after implant surgery, your body may be rejecting the titanium implant.
• Facial trauma: trauma to the mouth or face can cause the loss of artificial teeth, just like natural ones. Contact your surgeon immediately after an injury to determine whether the prosthesis can be saved and to replace any recently lost teeth.

Causes of Implant Rejection

The main causes of implant rejection are inflammatory and infectious processes. As pathogenic microorganisms multiply, mucositis first develops – a purulent inflammation without bone resorption. If left untreated, it progresses to peri-implantitis – an infectious inflammation with exposure, damage, and resorption of hard tissues.
Advanced peri-implantitis involves purulent granulations, gum recession, and bone loss around the implant and neighboring teeth.

Rejection can occur due to oral diseases and systemic conditions that are relative or absolute contraindications to implantation, such as:
• bruxism
• malocclusion
• temporomandibular joint dysfunction
• allergic reaction to implant materials
• bone deficiency
• periodontitis
• osteoporosis
• hormonal changes
• facial trauma

Mucositis and peri-implantitis are triggered by many factors, which can be divided into two groups:
• doctor-related errors
• patient-related actions

Doctor-related causes:
• failure to follow aseptic and antiseptic protocols during surgery
• use of an implant of incorrect size or shape
• insufficient examination, planning, and preparation
• violation of the implantation protocol
• poorly manufactured prosthetic construction

Patient-related causes:
• smoking
• poor oral hygiene
• excessive chewing loads (e.g., nuts, chips, crackers, steaks, raw vegetables, hard fruits, or other solid foods in the first weeks after implantation)
• refusal to take prescribed medications in the postoperative period
• failure to follow restrictions during the first weeks (e.g., sports, swimming in open water, visiting spas or tanning salons)

What to Do in Case of Implant Rejection

Implant rejection does not always present with obvious symptoms. If you notice any alarming signs, you should immediately see the doctor who performed the procedure. The surgeon will determine whether the symptoms are due to rejection or another cause.

Before visiting the doctor, you may:
• take a nonsteroidal anti-inflammatory drug (NSAID)
• apply a cold compress to the cheek for 10–15 minutes
• take an antipyretic if you have a fever

It is important not to use NSAIDs or fever-reducing medications for an extended period, and never take antibiotics without a doctor’s prescription.

Diagnostics

Patients with signs of implant rejection undergo a thorough examination, including:
• assessment of gum condition
• check for inflammation, swelling, and color changes of the mucosa
• evaluation of bone tissue visually and with equipment
• determination of implant mobility
• check for presence or absence of pus around the implant neck and body
• palpation of submandibular lymph nodes, which may be enlarged in case of infection

Based on the results, the exact cause of pain and inflammation is identified, and a treatment plan is developed.

How to Restore a Dental Implant After Rejection

Treatment strategies vary, and removal is not always necessary. Even if removal is required, in 80% of cases the implant can be replaced with a new one.

The treatment plan depends on the condition of the surrounding tissues:
• If only the superficial periodontal layers are affected: the cover screw is removed and cleaned, the gums are disinfected, and the screw is reinstalled.
• If the infection has spread to bone tissue: the implant is unscrewed, affected hard and soft tissues are excised, the wound is disinfected, and anti-inflammatory and antibacterial medications are prescribed. After healing, artificial bone grafting is performed.
• If the purulent process affects deeper periodontal layers with significant bone loss: the implant cannot be saved. It is removed, antibiotics are prescribed, guided bone regeneration is performed, and a new implant is placed after 2–6 months.

Is Reimplantation Always Possible After Rejection?

The possibility of reimplantation depends on the cause of rejection. Reimplantation is not recommended if the implant failed due to smoking, poor oral hygiene, or non-compliance with postoperative restrictions, until the patient changes their lifestyle.
It is also contraindicated if systemic diseases, allergies, or critical jawbone atrophy prevent osseointegration. In other cases, the success rate of reimplantation is high.

Prevention of Implant Problems

The success of implant integration depends on both the patient and the doctor. You can significantly reduce the risk of rejection by following postoperative recommendations:
• quit smoking: both regular and electronic cigarettes, as well as vaping, increase the risk of implant rejection fivefold
• take prescribed medications: antibiotics, anti-inflammatory drugs, pain relievers, and other prescribed medicines prevent complications and ease recovery
• follow a gentle regimen: reduce physical activity in the first weeks, avoid lifting heavy objects, sports, prolonged sun exposure, tanning salons, spas, saunas, swimming pools, or open water; showers are recommended instead of baths
• maintain a proper diet: avoid hard foods in the first weeks to reduce chewing load and prevent implant overload or displacement
• practice good oral hygiene

Dental implants are a long-term investment in your health and confidence. While complications are rare, recognizing the signs of rejection can be crucial. Choose an experienced implant specialist. Skilled oral surgeons at YAREMA DENTAL will carefully assess your oral condition before recommending implants and will carry out the entire process with special care.