Dental Caries Overview and Types

Describing Dental Caries

• Dental caries, also known as dental decay, is a dynamic process of demineralization and remineralization.
• It begins when bacteria in the mouth digest carbohydrates, producing acids.
• These acids break down tooth enamel and dentin, leading to tooth decay.
• Initially, the decay is reversible, but prolonged acid attack makes it irreversible.

Types of Dental Caries

• Arrested/Inactive Caries: When the balance between demineralization and remineralization favors remineralization, the decay may stop. A scar might remain. This can be caused by improved oral hygiene and other preventative measures. Treatment may involve fluoride application or composite/glass ionomer cement if discolouration needs correcting. Continued prevention remains important as the initial cause may return.

• Root Caries: Affects cementum, then dentin. Develops when the root surface is exposed due to gum recession, allowing bacteria colonization. Root caries progresses faster than enamel caries because cementum is softer. Factors influencing it include decreased saliva flow (xerostomia) which reduces mineral reservoir for remineralisation and issues associated with radiotherapy and trismus (limited jaw motion). Preventative measures include improved oral hygiene, dietary adjustments, fluoride use and potentially saliva substitutes and medication. Treatment includes restoring cavitated lesions, but isolation is sometimes challenging.

• Early Childhood Caries: Defined by the American Dental Association (ADA) as presence of one or more decayed, missing, or filled tooth surfaces in a preschool-aged child. Previously known as 'bottle caries' or 'nursing caries'. Defined as a child under 6 who experiences decay.

• Rampant Caries: An extensive form of caries affecting multiple teeth rapidly. This form is often more resistant to decay, for example, mandibular incisors. This can be early childhood related, or caused by conditions such as xerostomia or radiotherapy. Treatment of rampant caries requires comprehensive prevention, followed by stabilisation using temporary restorations to evaluate response prior to permanent restorations.

• Caries Based on Anatomical Position: This categorizes caries based on its location on the teeth:

• Class I: Pit and fissure caries in premolars, molars (occlusal 2/3 of buccal, lingual, and palatal surfaces of anterior teeth).

• Class II: Caries on proximal surfaces of premolars and molars.

• Class III: Caries on proximal surfaces of anterior teeth (incisors and canines) that do not include the incisal edge.

• Class IV: Caries on proximal surfaces of anterior teeth that also involve the incisal edge.

• Class V: Caries on the gingival third of facial, lingual, or palatal surfaces of all teeth.

• Class VI: Caries on incisal edges of anterior teeth or cusp tips of posterior teeth, without involving any other surface.

• Primary/Secondary: Primary refers to decay on surfaces not previously treated, secondary is decay on previously treated surfaces.

• Residual: This is decay left after restoration, may be intended (excavation, fissure seal) or unintentional (missing caries removal).

• White Spot Lesions/Incipient Caries: The earliest detectable evidence of decay, usually not reaching the dentin-enamel junction. These lesions can be remineralized with proper preventative care.

• Additional learning resources include lectures on detection and management of caries with a particular focus on prevention strategies.