July 12, 2020
Most of us have heard about kidney stones or gall stones. But in the world of dentistry some similar abnormal structures are often encountered. These are called pulp stones.
When we see a human tooth, we can see the hard tissue covering it which is known as the enamel. A layer below it lies the dentin which is sandwiched between the enamel and a soft tissue component known as the pulp. The pulp is home to the nerves and blood vessels that supply the tooth. Calcified structures found in the pulp are called pulp stones.
Pulp stones are one of the most entropic entities in the dental world. Nearly every characteristic that leads us to describe them ends up in a range of possibilities. To begin with, pulp stones can either be found in the crown portion of the tooth or the root. They can be as small as 0.05 mm in diameter to as large as 4 mm. They can be found in milk teeth or permanent teeth. They might be found only in a single teeth or can be found in an entire dentition. One might encounter only 1 pulp stone or over 10 in number in a single tooth.
In addition to these features, there are multiple theories that have tried to explain the formation of these blends of calcium and phosphorous. It is essential to know that pulp stones are of two primary types depending on their core contents.
When a person ages, the pulp gradually diminishes in size. The most commonly accepted school of thought says that during this process, the secondary layer of dentin contributes chiefly to the formation of pulp stones. These forms of pulp stones are called true stones, where they are lined by the cells of dentin. If the cells of the pulp itself degenerate, they often get mineralised (impregnated with minerals) in the process leading to another type of pulp stones. These are called false pulp stones. These pulp stones may or may not be adhered to the walls of the dentin.
Let us briefly see all the commonly discussed theories that might explain the formation of pulp stones.
• These can be freely present in the pulp, around a nerve bundle. This might explain those cases where pain is present in the tooth.
• The ageing process reduces the total density of the cells in the pulp which can pave then way of cells like fibroblasts (fibre laying cells) to lead to calcifications.
• Some others believe that fat deposits in that small space within the tooth are responsible for formation of pulp stones.
• The pulp itself consists of certain cells that can differentiate into any other type of cell. These cells are called undifferentiated mesenchymal cells and there is quite a possibility that they contribute to the formation of pulp stones.
• Pulp stone formation may also occur in previously carious teeth that were later restored.
• During the development of tooth, the cells responsible for root formation might form calcification within the root.
An individual might be suffering from mild to severe pain because of a pulp stone. However, may times the presence of a pulp stone might not be even known to the individual and he might be asymptomatic. On an x-ray, pulp stones can be seen as whitish structures in the pulp chamber. The pulp stones can be round, ovoid or may even lack a definite shape.
A dentist can find out a pulp stone on the radiograph but at times when the pulp stone is too small, it might not be too evident. In such cases, the dentist encounters pulp stones during a root canal procedure. When performing a root canal, a dentist needs to clean and shape the canals of the roots with thin needle-like instruments called files. When the file is inserted, a present pulp stone might block its path. This is when through careful instrumentation a dentist removes the pulp stone. He/she also uses a chemical called sodium hypochlorite during this procedure as it facilitates the dissolving of the pulp stone. In some cases, if the pulp stone is present in the crown, then a dental drill and a bur might be used to remove it. There are also certain ultrasonic tips that a dentist can use in order to further ease the removal of pulp stones.
Pulp stones do not necessarily contribute to pain. However, their removal is of prime importance in those individuals undergoing a root canal procedure. Individuals suffering from certain genetic syndromes, connective tissue disorders, kidney or heart diseases are at a greater risk of developing pulp stones. Overall, the incidence of pulp stones is minimal and they do not pose any major threat.