Handbook of Oral Pathology and Oral Medicine. S. R. Prabhu

black or white chalky discoloration

       Oral malodour

      2.5.1 Primary Caries

       Decay at a location that has not previously experienced decay

      2.5.2 Secondary Caries (Recurrent Caries)

       Appears at a location with a previous history of caries

       Frequently found on the margins of fillings and other dental restorations

      2.5.3 Arrested Caries

       A lesion on a tooth that was previously demineralized but was remineralized before causing a cavitation

      2.5.4 Rampant Caries

       Severe decay on multiple surfaces of many teeth (Figure 2.1)

       Those at risk: individuals with xerostomia, poor oral hygiene, drug‐induced dry mouth, large sugar intake and radiation to the head and neck region

       Treatment options include therapeutic and preventive strategies, including diet modificationsFigure 2.1 Rampant caries(source: From Mary A. Aubertin. 2014. Common Benign Dental and Periodontal Lesions. In: Diagnosis and Management of Oral Lesions and Conditions: A Resource Handbook for the Clinician, ed. Cesar A. Migliorati and Fotinos S. Panagakos, IntechOpen, doi: 10.5772/57597).

      2.5.5 Early Childhood Caries

       Rampant dental caries in infants and toddlers; also known as baby‐bottle caries

       Most likely affected teeth: maxillary anterior deciduous teeth (Figure 2.2)

       Cause: allowing children to fall asleep with sweetened liquids in their bottles or feeding children sweetened liquids multiple times during the day

       Education of parents/carers to follow healthy dietary and feeding habits to prevent the development of early childhood caries is important

      2.5.6 Methamphetamine‐Induced Caries

       Rampant caries often found in methamphetamine users and is often called ‘meth mouth’

       The dental symptoms of methamphetamine users include poor oral hygiene, gingival inflammation, xerostomia, rampant caries and excessive tooth wearFigure 2.2 Early childhood caries(source: by kind permission of Dr Sadashivmurthy Prashanth, JSS Dental College, Mysuru, India).Figure 2.3 Caries in a methamphetamine user(source: From Mary A. Aubertin. 2014. Common Benign Dental and Periodontal Lesions. In: Diagnosis and Management of Oral Lesions and Conditions: A Resource Handbook for the Clinician, ed. Cesar A. Migliorati and Fotinos S. Panagakos, IntechOpen, doi: 10.5772/57597).

       The pattern of caries is distinctive: it tends to start near the gums and involves the buccal smooth surface of the posterior teeth and the interproximal space of the anterior teeth, and progresses to complete destruction of the coronal portion of the tooth (Figure 2.3)

       The key to successful dental treatment is cessation of methamphetamine use.

      2.5.7 Radiation Caries

       Radiation caries is a complication of head and neck cancer radiotherapy

       Typical radiation caries is characterized by enamel erosion and dentin exposure (Figure 2.4)

       Indirect effects of radiotherapy include changes in salivary quantity and composition, together with alteration of the oral flora. These changes are widely regarded as the major causes of radiation cariesFigure 2.4 Radiation caries(source: by kind permission from Dr Vlaho Brailo, School of Dental Medicine, University of Zagreb, Zagreb, Croatia).

       Management of radiation caries includes management of xerostomia and restorative treatment radiation‐induced dental caries. Glass ionomer cements have proved to be a better alternative to composite resins in irradiated patients.

2.6 Differential Diagnosis

       Hypoplastic enamel

       Hypocalcified enamel

       Fluorosis

       Stains

2.7 Diagnosis

       History

       Clinical examination: initially a chalky white spot lesion

       Blowing air across the suspected tooth surface is useful

       Later stages cavitation

       Radiography/laser detection

2.8 Microsopic Features

      2.8.1 Enamel Caries

       Early enamel lesion shows:Conical lesion with its apex towards dentinLesion shows four distinct zones of differing translucency (Figure 2.5a and b)Translucent zone (deepest zone)Figure 2.5 (a) Early approximal enamel caries. Undecalcified section of a precavitation stage of enamel caries showing a cone‐shaped carious lesion on the proximal surface of the tooth with its apex towards dentine. The intact surface layer and the body of the lesion are visible. Evidence of early demineralization of dentine is seen beneath the amelodentinal junction deep to the carious enamel lesion. This is due to the diffusion of acids from the enamel lesion into the dentine. The dentine also shows numerous dead tracts. (b) Early pit and fissure enamel caries. Undecalcified section showing precavitation stage of enamel caries surrounding an occlusal pit. The dense surface zone, main body of the lesion, dark zone and peripheral translucent zones are visible.(Source: by kind permission of David Wilson, Adelaide, Australia.)Dark zone (superficial to the translucent zone)Body of the lesion (extends from beneath the surface zone to the dark zone)Surface zoneCaries reaches enamel–dentin junction and spreads laterally, undermining the enamel

       Characteristics of enamel preceding cavitation:Translucent zone:1% mineral lossDark zone:2‐4% mineral loss overall. A zone of remineralization behind the advancing front becomes evidentBody of the lesion:5‐25% mineral lossSurface zone:1% mineral loss

      2.8.2 Dentinal Caries

       Dentin caries shows a conical lesion with broad base at the enamel–dentin junction and apex towards pulp

       Bacterial colonies infiltrate dentinal tubules (Figure 2.6 a and b)

       Three zones of dentinal caries seen:zone of demineralizationzone of bacterial penetrationzone of dentine destructionFigure