What is Apical Periodontitis?
Apical periodontitis is an inflammation around the root tip of a tooth, caused by diseases of the tooth’s inner part, or pulp. This can be brought about by advanced tooth decay, injury, or dental procedures. Essentially, it’s the body’s reaction to harmful bacteria from an infected pulp that triggers inflammation, resulting in the damage of the tissues around the root of the tooth.
Diseases at the root tip of the tooth can show up in different ways – from no clear signs or symptoms to severe bone damage, with or without a pus-filled abscess forming. Therefore, it’s essential to correctly identify, diagnose, and treat diseases at the root tip of the tooth to avoid severe symptoms or to prevent further damage.
What Causes Apical Periodontitis?
The inside of your tooth is filled with a soft tissue called dental pulp. This tissue is protected by hard, outer enamel, and a healthy support system of ligaments, bone, and gum tissue. When things like cavities or trauma create openings in the tooth, bacteria can enter and cause inflammation in the pulp, which leads to the formation of a protective layer of dentin.
If the inflammation becomes severe, it might damage the pulp cells and risk the overall health of the pulp. Our immune system typically fights infections, but in this case, immune cells have difficulty reaching the bacteria due to the tooth’s hard enamel and structure.
Once the pulp’s blood supply is affected, it often leads to pulp death and disease in the root of the tooth. This pulp death can occur in stages, with some parts dying before others.
The infected and dead root canal then becomes a place where bacteria can thrive, especially anaerobic bacteria, which do not need oxygen to survive. These bacteria or their waste products can move to the root of the tooth, prompting the body to mount a defense.
This battle between bacteria and the body’s defense system can cause damage to the tissues around the tooth root, such as ligaments and bone. This can lead to periodontal lesions or sores. These sores can look different depending on each case.
Apical periodontitis is an inflammatory condition caused by this interaction of bacteria and our body’s defense mechanisms around the root of the tooth. Despite our complex defense systems, the bacteria invade the delicate root canal, which can’t be reached by our defenses. So, the condition will not heal on its own and can only be treated with endodontic therapy, a treatment for the inside of the tooth, or the removal of the affected tooth.
Risk Factors and Frequency for Apical Periodontitis
About half of adults around the world have experienced apical periodontitis (AP), a condition that affects the teeth. This condition appears to be slightly more common in developing countries, perhaps due to issues related to healthcare access and patient education. People with systemic diseases also tend to show a higher prevalence of AP.
People with diabetes are often more likely to lose teeth and to undergo treatment for tooth-related issues. This is because diabetes can cause increased inflammation, reduce the body’s ability to repair tissue, weaken the response to infections, and slow down wound healing.
- About 52% of adults globally have a tooth affected by apical periodontitis.
- It’s slightly more common in developing countries potentially due to healthcare access and patient education.
- The condition is more prevalent in individuals with systemic diseases.
- Diabetic patients have a higher propensity for tooth loss and need for tooth-related treatments due to chronic inflammation, reduced tissue repair, weak response to infections, and slow wound healing.
- Patients who had endodontic therapy in the past also have a greater chance of having apical periodontitis than those without such treatment.
Signs and Symptoms of Apical Periodontitis
When a patient comes in, it’s vital for healthcare providers to gather a complete medical history, including any medications and allergies. This helps in diagnosing certain dental conditions, like apical diseases, which can be treated with antibiotics to reduce the bacterial buildup associated with them. By understanding the patient’s symptoms, healthcare providers can identify the root cause of the dental problem. Sometimes, certain dental abnormalities might be discovered during a routine check-up and might not present any symptoms. After a detailed clinical and visual inspection, the healthcare provider needs to figure out if these abnormalities originate from the teeth or elsewhere.
One such dental problem is apical periodontitis, a condition characterized by inflammation in the tissues around the tip of the root of a tooth. This can be categorized into two types:
- Initial apical periodontitis (or acute apical periodontitis)
- Chronic apical periodontitis
Initial apical periodontitis can result from an infection or inflammation that isn’t caused by bacteria. The condition can be triggered by an invasion of microbes into the tissues around a tooth, physical trauma, surgery-related injury, and irritation due to chemical or dental substances. At this stage, patients may experience pain, sensitivity to pressure, difficulty eating, and a feeling of tooth elevation. Clinicians mostly rely on patients’ reported symptoms during diagnosis since there are no visible changes in the tissues surrounding the tooth tip in the early stages. This is because the inflammation is restrictive to the ligament that attaches the tooth to its socket, and there hasn’t been enough time for significant tissue changes to occur.
During this stage, inflammation triggers white blood cells (neutrophils) to move to the affected area to fight off the harmful microbes. More immune cells are called to the site due to chemical signals (leukotrienes and prostaglandins) released by the neutrophils. Activated immune cells (macrophages) further release substances that intensify the body’s vascular response and bone resorption process. From here, the acute phase can either heal or develop into a worsening infection. If treatment is initiated correctly and any sources of infection in the root canal are removed, the lesion can resolve, leaving the surrounding tissues unchanged. However, if the infection persists, it becomes chronic, leading to complications like abscesses and fistulas.
Chronic apical periodontitis occurs when oral microbes persist, causing the predominant immune response to shift from neutrophils to macrophages and connective tissue encapsulation. Unlike acute conditions, chronic lesions are typically asymptomatic. As a result, changes can be noticed on an X-ray due to the destruction of the ligament that attaches a tooth to its socket, and the bone that houses the tooth. In the chronic phase, the disease can remain dormant and symptom-free for an extended period, without significant changes in the X-ray. This is due to a decrease in bone resorption and an increase in the production of connective tissue growth factor, caused by cytokines produced by certain immune cells (activated T-cells).
Testing for Apical Periodontitis
When a tooth hurts, it’s important for a dentist to identify the exact cause of the pain before starting any treatment. One way to do this is by trying to recreate the patient’s symptoms, which can help accurately diagnose the problem and make sure the treatment fits the diagnosis.
There are several tests a dentist may use to assess the condition of a tooth. This typically involves checking the vitality, sensibility, and sensitivity of the tooth. Vitality testing measures the blood supply to the pulp (the living tissue inside the tooth), while sensibility tests determine the tooth’s response to sensations like electricity and temperature. A tooth with normal dental pulp would react within normal limits and the sensation wouldn’t last longer than 30 seconds. Pulpitis, a condition that causes tooth pain, can cause an exaggerated and long-lasting response that lasts more than 30 seconds. The severity of the pain and its duration can help determine whether pulpitis is reversible or irreversible. When no response to the testing is elicited, it’s an indication that the pulp is necrotic, or essentially dead.
There are two types of apical periodontitis, acute and chronic. In acute apical periodontitis, the pulp might still be vital or could have become necrotic. The tooth will be sore and cause pain when tapped. An x-ray of the tooth might show nothing unusual or might only show slight changes around the tooth root. In contrast, chronic apical periodontitis means the pulp is not only necrotic but also infected. Therefore, testing the tooth’s sensibility won’t cause a reaction. The tooth won’t be tender to touch or pressure, but it might be a bit loose and feel different. The dentist will see a radiolucent, or darker, lesion around the tooth root on an x-ray, confirming chronic apical periodontitis.
Treatment Options for Apical Periodontitis
The goal of treatment for a root canal is to remove or significantly reduce the bacteria within the tooth and to prevent future infections by filling the root canal. If the treatment is done correctly, the area surrounding the root of the tooth – called the periapical lesion – should heal. This healing can be seen on x-rays as the once visible dark area decreases in size. Most periapical lesions will heal completely in six months to two years, but in some cases, they may continue to be an issue.
Follow-up visits are crucial to check how effective the treatment was. If the periapical lesion doesn’t change in size after a year, increases in size, or appears on a tooth that went through root canal treatment, additional treatment may be needed.
In some situations, a periapical lesion lingers because the root canal treatment wasn’t able to control the infection, often due to a lapse in certain steps. Some of these steps might include not maintaining sterile conditions, not correctly cleaning and shaping the tooth, making an insufficient access hole to the inner tooth, missing canals, or leaking fillings.
Even after meticulous treatment, some periapical lesions may persist because of the intricate structure of the root canal system. If a tooth shows issues after treatment, non-surgical root canal retreatment or root-end surgery are common solutions to save the tooth.
The use of antibiotics is usually not recommended, except for instances with rapid onset or if the infection spreads throughout the body. These scenarios may include swollen lymph nodes, illness, sudden symptoms appearing in less than 24 hours, and fever over 38 degrees Celsius. Even though they aren’t usually used, antibiotics might be needed for patients with weakened immune systems.
What else can Apical Periodontitis be?
When we talk about areas on dental X-rays that appear darker than usual (what doctors call “apical radiolucencies”), it can indicate a few different conditions:
- Growth around the root tip of the teeth (Periapical granuloma)
- A type of cyst around the tooth’s root (Periapical cyst)
- A small fluid-filled bump near the root of the tooth (Lateral periodontal cyst)
- Cysts related to impacted teeth (Dentigerous cysts)
- Unusual cysts inside the mouth (Odontogenic keratocysts)
- A rare, non-cancerous tumor in the jaw (Ameloblastomas)
On the other hand, areas appearing light or white on X-rays (known as “apical radiopacities”) could suggest a few different conditions too:
- Extra growth of the cementum, which is a hard tissue that covers tooth roots (Hypercementosis)
- A bone disorder that affects the jaw and teeth (Cemento-osseous dysplasia)
- A condition that causes the formation of dense bone (Idiopathic osteosclerosis)
It’s worth noting that these radiopacities are not typically linked directly to infections inside tooth roots. You might see these white areas on usual dental X-rays, and they are generally not harmful or serious.
What to expect with Apical Periodontitis
Long-term results show that endodontic microsurgery techniques used for treating root problems have high success rates, lasting from 2 to 13 years. The success rates are highest when the treatment is first carried out.
Research shows that non-surgical endodontic therapy, or treatments done inside the tooth but not involving surgery, have an impressive success rate of 85 to 94%. This depends on whether there is a certain type of abnormality on the X-ray.
However, when non-surgical endodontic retreatment, which is a second non-surgical treatment, is performed, the success rate drops to 74 to 82%. Further, surgeries involving the apex of the tooth root, or the periapical area, have a success rate between 60 and 91%.
A specific type of surgery known as a root-end resection and root-end fill is usually carried out using specialized microscopes and delicate instruments. It involves the removal of the root tip and filling the root from the tip to the top.
A follow-up X-ray at 12 months after treatment is vital for dentists to assess treatment success. 88% of the abnormal areas, or lesions, show signs of healing after a year, compared to just 50% showing improvements at the 6-month check.
The dentist should also carefully note the lesion’s size, shape, and appearance both in person and on the X-ray. This provides helpful information for comparison during future visits.
Possible Complications When Diagnosed with Apical Periodontitis
Following a dental procedure known as an endodontic treatment, some patients feel discomfort and notice swelling. This post-treatment phenomenon is often referred to as a “flare-up”, and they can happen anywhere from a few hours to a few days after the procedure. They are experienced by between 1.4% and 16% of the patients. Flare-ups can arise due to different reasons such as the presence of microbes, mechanical irritation, and chemical irritation.
An important cause of microbial flare-ups is the expulsion of dental debris from the root end of the tooth, also known as the apex, after the procedure. This expulsion occurs as a result of overly excessive instrumentation or mismeasurement during the procedure. As a response, our bodies increase inflammation to fight the released microbes. This sudden increase in inflammation can enhance blood vessel permeability, leading to swelling. As this swelling pressure increases, it can cause pain by compressing our nerve endings. Additionally, if the cleaning and shaping of the root canal isn’t thorough during the non-surgical endodontic treatment, any leftover bacteria could multiply and result in further harm to the surrounding tissues.
Mechanical flare-ups usually happen when the root’s apical third gets excessively opened due to over-instrumentation, or the filling materials get pushed out during obturation. To appropriately clean, shape, and prevent damage to the apex during the procedure, the correct working lengths must be used. Even the chemical irritants that get pushed into the area surrounding the apex could potentially heighten inflammation.
Odontogenic infections, or tooth-related infections, are the primary cause of deep abscesses in the facial planes of the head and neck. When the infection around the tooth’s apex spreads through the hard, outer layers of the upper or lower jawbone, the bacteria can infiltrate other areas, typically following the least resistance through soft tissue. Extremely severe infections could lead to a life-threatening condition called Ludwig Angina. It is a deep infection which rapidly spreads, poses a threat to the respiratory tract and necessary structures, and typically affects the area below the chin and both sides below the tongue and the lower jaw. In these emergency cases, oral and maxillofacial surgeons play a crucial role in the patient’s management and care.
Recovery from Apical Periodontitis
Studies have shown that teeth that are alive typically experience more pain after dental procedures than teeth that are already dead or have undergone prior treatment. Specifically, the rates of pain are around 64%, 38%, and 49% respectively. It’s also worth mentioning that patients with symptomatic apical periodontitis, a type of tooth infection, can predict an increase in pain following dental procedures.
In general, a dentist can manage this after-procedure pain using common medications like paracetamol or ibuprofen, which are readily available at pharmacies. A study by Stamos et al. showed that there’s no significant difference in pain management if a patient was given 600mg of ibuprofen alone or a combination of 650mg acetaminophen and 600mg ibuprofen, taken every 6 hours.
Preventing Apical Periodontitis
Regular, thorough check-ups with your dentist are super important. These can help find problems like infections or tooth decay early on. Dentists need to stress to their patients just how important these check-ups really are. Plus, if a patient has had root canal treatment before, they should be checked regularly. This is to make sure that the area is healing properly and there’s no sign of any new infections.
During these check-ups, the dentist will look for any new or worsening problems, and will also gauge the risk of the tooth getting infected again. Patients should also know that any tooth at the back of the mouth that has had root canal treatment will need a special type of filling. This filling is called a cuspal coverage restoration and it helps maintain the strength of the treated tooth.
