Introduction:
Dental pulp stones may be termed discrete calcifications that occur or appear within the pulp of the teeth. The pulp is a vital part of the tooth structure and a primary source of vascular and nerve supply to it. These calcifications can occur in any tooth: be it a healthy or carious tooth or, even unerupted teeth. Pulp stones may either exist freely within the pulpal tissue, or they may be found attached to or embedded in the dentin (calcified tissue of tooth which is made up of tubules) layer. While smaller pulp stones tend to range from microscopic particle size in the pulp chamber to moderate particle size, the larger pulp stones are calcified enough to obliterate even the pulp chambers and can even be appreciated radiographically by the dentist.
What Are the Features and Etiology of Dental Pulp Stones?
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Pulp stones may occur either in one or all of the teeth in one person. They can even occur in unerupted or impacted teeth.
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Located within the central pulp cavity or the root canal, these dental pulp stones are extremely narrow and cause a typical obstruction to the endodontist while accessing the apical point of the root canal space.
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Pulp stones would also vary in terms of the numbers and may range from being found from one to nearly 12 within a single tooth, according to endodontic case reports.
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The size of the pulp stones would differ, ranging from minute masses that resemble particles causing obstruction within the pulp cavity to large structures that occlude the pulp.
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The incidence of pulp stones is more often in coronal pulp compared to their incidence in radicular pulp.
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Studies show that more pulp stones tend to occur in the posterior teeth as compared to their incidence in the anterior teeth. Nearly around 87.33 % of posterior teeth are now suggested to be affected with pulp stones in clinical trial study groups, against 12.67 % of occurrences seen in anterior teeth.
What Is the Pathogenesis of Dental Pulp Stone Formation?
A number of predisposing risk factors, such as the natural physiology of aging, dental carious lesions, operative dental procedures, as well as periodontal diseases, have been implicated in the pathogenesis of dental pulp stone formation. The pathological effects, irrespective of any of the causative factors, are known to affect the pulpal tissue simultaneously, causing a vascular wall injury. These vascular injuries eventually result in the deposition of calcium salts within the pulpal tissue.
Other risk factors that may be a form of traumatic force on the pulp can be uncontrolled orthodontic tooth movements, idiopathic causes as well as genetic predisposing factors for the specific individual. Clinical research through microscopic and histochemical studies in the dentistry field suggests the exact cause of pulp calcifications may be of an unknown etiology.
However, there are several risk factors, like in any other local or systemic diseases, that can predispose an individual to develop pulp stones. These factors may vary based on the age, genetic predisposition of an individual, any low-grade traumatic impact or insults to the vital pulp tissue of the tooth, circulatory or immune disturbances in the body, etc. Certain research hypotheses also link that the inductive interaction which occurs between the pulp tissue and the epithelium would be actually behind the initiation and aggravation of degenerative changes occurring within the vascular pulp region, subsequently leading to pulp calcifications.
How Are Dental Pulp Stones Associated With Systemic Diseases?
Numerous clinical research data have also proposed models of the potential association between the formation of pulp stones in cardiovascular patients who have atheromatous plaques (build-up of fat and cholesterol) in their blood vessels. It has been demonstrated that approximately 74 % of patients who suffer from cardiovascular disease have detectable pulp stone formations, while only 39 % of patients who do not have any cardiovascular diseases may have a pulp stone formation risk. Several systemic links also exist for conditions that may predispose an individual to develop pulp stones, such as hypercalcemia (increase serum calcium level), gout (a type of arthritis), renal lithiasis (hard mineral and salt deposits in kidneys), etc.
How Are Dental Pulp Stones Classified?
According to Kronfeld and Boyle, the classification of pulp stones may be histologically categorized into two forms- true and false pulp stones.
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True Pulp Stones- The true pulp stones are histologically more irregular in shape and usually lined by odontoblasts. They are composed of dentine.
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False Pulp Stones- The false pulp stones, on the other hand, appear to be histologically constituted by the degenerated pulpal cells that have calcified. This calcification in false pulp stones may be attributed to the natural phenomenon of dystrophic calcification.
According to the endodontist, one more way for classifying pulp stones is based on their size as large or small. Based on the association with the surrounding vascularity or blood vessels, they can be categorized as diffuse or amorphous pulp stones.
How Are Dental Pulp Stones Radiographically Diagnosed?
Pulp stones can be identified by the dental clinician on radiographic examination by 2D or 3D dental radiographic imaging modalities like IOPA (intraoral periapical radiography, OPG (orthopantomogram), or CBCT (cone beam computed tomography). These can be seen as dense round or ovoid opacity or in presence of multiple pulp stones as pulpal opacities. However, oral pathologists report better visualization and analysis of pulp stones through histologic studies rather than mere radiographic interpretation or identification. This is because of the fact that radiographic studies cannot give a clear or accurate picture of the whole pulp cavity.
How Are Dental Pulp Stones Clinically Managed?
The clinical management of pulp stones is simple in the case of smaller pulp stones without much difficulty. The small pulp stones are not clinically challenging to the dental operator. However, when large pulp stones need to be eliminated, the endodontist can use varied methods to eliminate them both from the pulp chamber as well as the root canals. The large pulp stones can be preliminarily dissected from the access cavity using burs. Another alternative method is to use ultrasonic instrumentation with the use of specialized tips that makes the removal of large pulp stones easier compared to manual instrumentation through the burs.
Conclusion:
To conclude, pulp stones may be a common finding in the diseased, unerupted, or healthy tooth pulp, which needs timely dental management and is also linked with potential systemic conditions. Also, the calcification of pulp tissue is always considered a drawback in endodontic therapy because it may eventually lead to the potential failure of root canal therapy and loss of the tooth, especially when they have a chronic timeline associated.
