Overview

Pulp calcification is the formation of calcium deposits in the teeth.¹ Although, calcium is essential for maintaining the hard structure of our teeth, problems arise when calcification occurs in the wrong place. In the case of pulp calcification, the issue lies in its specific location. To fully understand the issues surrounding pulp calcification, it is essential to first understand the intricate structure of the tooth. 

The structure of a tooth 

Our teeth may seem simple on the outside, but beneath the surface are several layers, each serving an important role. There are three main layers of the tooth namely:²

• Enamel
• Dentine
• Pulp 

The visible part of the tooth located above our gums, which we maintain through brushing and flossing, is referred to as the crown.³ The crown is covered by a hard, calcium-rich enamel layer that shields the underlying layers from acidic foods, bacteria, and other potential damage.³ 

The root of the tooth, which anchors it to the jawbone, lies beneath the gums and is composed of a hard structure called the dentine.² Although, dentine is durable, it contains fewer minerals than enamel, making it softer.⁴ This softness allows dentine to absorb the pressure from chewing, which helps to prevent the enamel from breaking.⁴ Additionally, dentine surrounds and protects the soft tissue within the centre of the tooth, which is known as the pulp.⁵

The pulp is a soft tissue that contains a network of cells and tissues that help protect and maintain your teeth.³ These include:^5,6,7 

• Immune cells, which fight against bacteria
• Odontoblasts, which develop and maintain the dentine layer
• Blood vessels, which supply oxygen and nutrients for cells to survive
• Nerves, which detect discomfort 

What is pulp calcification? 

Calcification is when hardened calcium forms in unintended parts of your body, such as your tooth pulp, blood vessels, or kidneys, thereby affecting the function of these tissues and organs.^1,8,9 Calcification of the tooth pulp, known as pulp calcification, is generally harmless and does not require treatment, but it can put pressure on the nerves or blood supply, which in turn leads to pain or infection. 

Beyond these complications, the key question remains: does it matter if we have pulp calcifications? The answer is yes, especially for your dentist. Pulp calcifications can complicate certain dental procedures, making treatments like root canals more challenging to perform.¹⁰ Additionally, they can be useful indicators of underlying health conditions.¹¹

Causes and types of pulp calcification

Types of pulp calcification 

Pulp calcification can occur in different forms and regions within the pulp, and it is classed into two distinct categories.^12,13

• Pulp stones, which form within the pulp chamber
  • True pulp stone: is made up of dentine that is surrounded by odontoblasts
  • False pulp stone: is made up by the mineralisation of dying cells
• Pulp canal obliteration (PCO), which develops within the pulp canal
  • Partial obliteration: the pulp chamber is visible in the X-ray radiograph but the canal is narrowed
  • Total obliteration: both the pulp chamber and canal are not visible

How is pulp calcification caused? 

The exact mechanism of pulp calcification remains unknown, but the following highlights several suggested factors.

1. Trauma, such as a chipped or cracked tooth, can cause bleeding in the pulp that may result in damage to the odontoblastic cell, triggering pulp calcification¹³
2. Sugar is present in many of the foods we eat, both in added forms, like biscuits and chocolate, and in naturally occurring sources, such as honey and fruits. People with a high-sugar diet can cause the natural bacteria in their mouth to produce acids. This weakens the tooth by gradually wearing away the enamel layer, causing dental cavities.¹⁴ Cavities can cause irritation, leading to pulp inflammation, which could contribute to calcification¹² 
3. Pulp calcification can happen naturally through ageing. This is due to the dentine gradually depositing in the pulp space, causing it to narrow¹² 
4. There is also evidence showing that pulp calcification is more common in people who have had operative dental procedures¹³ 

Diagnostic importance 

How is pulp calcification diagnosed? 

Pulp calcification typically has no visible external signs, but symptoms like pain or, in the cases of PCO, a tooth appearing more yellow than the surrounding teeth, can result in its identification through recommended X-ray or cone-beam computed tomography (CBCT) scan.^15,16 

X-ray scan

X-ray scan is an excellent imaging tool, because they direct beams of radiation through your body, and as different materials absorb varying amounts of radiation, they allow for detailed imaging of your body's structures.¹⁷ 

Soft tissues, such as the pulp, do not absorb X-rays as well and will therefore appear darker in comparison to other tissues. However, denser parts of your body that have a lot of calcium, such as the enamel, will absorb X-rays the most and appear white. As pulp calcification is the aggregation of minerals, pulp stones in the pulp chamber and the narrowing of the pulp can be identified in X-ray radiographs. 

CBCT scan

The limitation of X-rays is that they cannot detect pulp calcifications smaller than 200 µm. In such cases, CBCT can be used for a more accurate diagnosis.¹⁶ Although it also uses X-rays, it provides more detail and accuracy due to its 3D imaging. 3D imaging is possible as the scanner will move around your head in circles, taking images at different angles.¹⁸ 

How does pulp calcification affect root canal treatment?

What is a root canal treatment? 

Root canal treatment (RCT) is used to counter infections and diseases affecting the deeper layers of the tooth, including the pulp and the area surrounding the root, known as the periapical region.¹⁹ These treatments are commonly used to maintain the natural teeth of the growing elderly population.²⁰ In the procedure of treating an infected/inflamed pulp, a drill will be used to penetrate through the crown and access the pulp. The affected pulp will be removed, and the inside of the tooth will be carefully cleaned and disinfected before it is sealed with a rubber-like material known as gutta-percha. 

Pulp calcification and RCT

Since pulp calcification narrows the pulp, it becomes more challenging to access and remove the affected tissue, as well as to clean and shape the canal system.²¹ 

How is pulp calcification linked to systemic health issues? 

Since calcification can occur in other parts of the body, researchers have questioned whether certain health conditions are linked to pulp calcification. Studies have shown that many patients with atherosclerosis and cardiovascular disease also have pulp calcifications. Due to this positive correlation, some experts suggest that dental radiographs could help identify individuals at risk of cardiovascular disease and those who may require further evaluation.⁹ This is significant because it could provide a non-invasive method for detecting undiagnosed conditions, potentially preventing serious health complications.

Management and treatment

Pulp calcification may not need treatment as it typically does not cause adverse effects. If there is discolouration of your tooth, then this can be treated by bleaching techniques.²²

Also, some dentists may suggest the removal of pulp canal obliteration (PCO), as there have been a few cases where it has led to infection. There are different methods that can remove pulp calcification, which include: 

• Ultrasonic instrumentation²³
  • This uses special tip and high-frequency sound waves to clean and shape the root canals
• Dental burs²⁴
  • A dental bur is an instrument that can cut hard tissue like enamel
  • This can be used to dissect large pulp stones
• Guided endodontics²⁵
  • It is a stereo camera connected to a dynamic navigation system, used to guide the drill into the pulp chamber in real time with precision
  • This can be recommended for severe PCO²⁶

Prevention

It is important to remember that pulp calcification is a process that can happen naturally over time. It may not be possible to prevent it entirely, but the chances of it occurring can be reduced. To reduce the chances of it developing, you could: 

• Regularly brush and floss your teeth 
• Avoid sugary foods 
• Avoid smoking
• Avoid activities that can cause trauma to your teeth
• Have regular dental checkups 

FAQs

Can pulp calcification heal itself? 

No, in severe cases where it is painful or has resulted in infections, removal will be required.

What is the difference between pulp necrosis and pulp calcification? 

They are not the same, as pulp necrosis is when the tissue of the pulp is dying. However, PCO can eventually result in pulp necrosis if not treated.²⁷ 

Are pulp stones rare? 

They are not uncommon.²⁸ 

Summary

Pulp calcification is the formation of hard mineral deposits within the dental pulp. It is often harmless and asymptomatic, but it can result in pain or infection, requiring the removal of the pulp stone or PCO. Pulp calcification can sometimes complicate dental procedures such as RCT and be a useful indicator of systemic conditions like cardiovascular disease. In conclusion, a better understanding of pulp calcification is essential for improving diagnosis, treatment planning, and overall health assessments.