Development and Diagnosis of Carious Lesions
Introduction
A carious lesion should be regarded not as a disease entity, but as tissue damage or a wound caused by the disease dental caries. The coronal lesion begins as clinically undetectable subsurface demineralization of enamel, visible only at microscopic level, and gradually progresses, first to visible demineralization of the enamel surface and to cavitation of the dentin, and finally to complete destruction of the tooth crown despite restoration, but without prevention (Fig 145).
On the tooth crown, primary carious lesions are usually supragingival and particularly common on the occlusal surfaces of the molars and the approximal surfaces of the posterior teeth. In highly caries-active individuals, lesions may also develop on the approximal surfaces of the incisors, the buccal surfaces of the posterior teeth, and the lingual surfaces of the mandibular molars.
In elderly people and other adult caries-risk patients with root surfaces exposed by periodontal disease, root caries may also develop. In most industrialized countries with well-organized dental care, primary caries accounts for almost all lesions up to the age of 20 years. In adults older than 40 years, about 90% of lesions are secondary caries.
According to the World Health Organization (WHO) system, the shape and the depth of the carious lesion can be scored on a four-point scale (D1 to D4):
· D1: clinically detectable enamel lesions with intact (noncavitated) surfaces
· D2: clinically detectable "cavities" limited to the enamel
· D3: clinically detectable lesions in dentin (with and without cavitation of dentin)
· D4: lesions into pulp
For diagnosis and assessment of treatment need, it is important to note that enamel,
dentin, and root caries may be detected clinically at the noncavitated stage, as well as
with cavitation. In state-of-the-art dental practice, all noncavitated lesions can and
should be arrested; ie, a preventive, noninvasive approach is required.
It is also important to determine whether the lesion is active or inactive. This is of
particular importance with respect to visible enamel and root surface lesions. Table 15
shows the clinical diagnosis related to the type, localization, size, depth, and shape of
the carious lesion.
