Dental lesions are areas of damage or decay on a tooth’s surface. These defects impact the tooth’s structure and health. Class V lesions represent a specific category of these defects, found in precise areas on a tooth.
Understanding Class V Lesions
A Class V lesion is a type of dental cavity or non-carious lesion that develops on the smooth surfaces of teeth. These lesions are shallow and can appear saucer-shaped or wedge-shaped. They are distinguished by their specific location, part of a classification system developed by G.V. Black in 1896.
This classification system helps dental professionals categorize cavities by their location. Class V lesions are unique, found in a region susceptible to both decay and non-decay related wear.
Specific Locations of Occurrence
Class V lesions occur in the cervical third of the tooth, the area nearest to the gumline. This location can be on the facial (cheek side) or lingual (tongue side) surfaces of any tooth, including front (anterior) and back (posterior) teeth. Anterior teeth and premolars are frequently observed to have these lesions.
These lesions are found at the junction where the tooth emerges from the gum tissue. This area often includes the cementoenamel junction (CEJ), where the enamel of the crown meets the cementum of the root. Enamel in this cervical region is thinner, and if gum recession occurs, the softer root surface (dentin or cementum) can become exposed, making it more vulnerable.
Contributing Factors at These Sites
Several factors contribute to the formation of Class V lesions. One cause is aggressive tooth brushing, particularly with hard-bristled toothbrushes or improper technique. This can lead to mechanical wear and abrasion of the tooth structure in the cervical area.
Acid erosion also plays a role. Regular exposure to acidic foods and drinks, or gastric acids from conditions like acid reflux, can demineralize enamel and dentin. The gumline is susceptible to this erosion because enamel is thinnest there, and exposed root surfaces lack a protective enamel layer.
Excessive biting forces, known as occlusal stress or abfraction, also contribute to these lesions. When teeth are subjected to heavy or misdirected forces, flexural stress can occur at the neck of the tooth near the gumline. This stress can cause microscopic cracks and loss of tooth structure in the cervical region, creating a wedge-shaped defect.
Periodontal disease and gum recession can expose the softer root surface, composed of dentin and cementum, to the oral environment. These tissues are less mineralized than enamel, making them more vulnerable to wear from brushing and demineralization from acids. When gums recede, the previously protected root surface becomes exposed, increasing the likelihood of Class V lesion development.