Dental Erosion : Etiology , Diagnosis and Prevention

Dental erosion is a prevalent condition that occurs worldwide. It is the result of exposure of the enamel and dentin to nonbacterial acids of extrinsic and intrinsic origin, whereby mineral loss occurs from the surface of the tooth. The most frequently affected areas are the palatal surface of maxillary incisors and the occlusal surface of the mandibular first molars in adolescents. Characteristic early signs of dental erosion include smooth and flat facets on facial or palatal surfaces, and shallow and localized dimpling on occlusal surfaces. Early intervention is key to effectively preventing erosive tooth wear. Effective prevention of dental erosion includes measures that can avoid or reduce direct contact with acids, increase acid resistance of dental hard tissues and minimize toothbrushing abrasion. Introduction Dental erosion is the loss of dental hard tissue, associated with extrinsic and/or intrinsic acid that is not produced by bacteria. Though the chemical process of dental erosion is similar to that of caries, i.e., dissolution of hydroxyapatite by acids, the clinical manifestations and management of dental erosion are fundamentally different from caries because the erosive process does not involve acid of bacterial origin. Dental erosion does not begin as a subsurface enamel lesion that is conducive to remineralization, as in the caries process, but rather as a surface-softening lesion that is susceptible to wear and resistant to remineralization by conventional therapies. It is often widespread and may involve the entire dentition. Dental hard tissue loss associated with erosion is almost always complicated by other forms of tooth wear such as attrition and abrasion. Dental erosion results in tooth surface softening, which inevitably accelerates tissue loss caused by tooth-to-tooth contact while chewing and grinding (attrition) or by abrasive wear while mechanically brushing or cleaning tooth surfaces (abrasion). If dental erosion is not managed through effective interventions, it may result in substantial loss of enamel and subsequent exposure of the underlying dentin, which can, in turn, lead to dentin sensitivity, loss of vertical height and esthetic problems. Effective management of dental erosion is largely dependent on a thorough understanding of its etiology and early recognition of its signs and symptoms in clinical practice. Prevalence Dental erosion is a common condition, and its prevalence seems to be trending higher in recent decades.1 It is difficult to accurately assess the prevalence of dental erosion from published literature, for there is not a universally accepted standard for clinical evaluation of this condition. Dental erosion is almost always complicated by other forms of tooth wear. The reported prevalence of dental erosion varies greatly in the literature, which can be partially explained by age, country and different evaluation standards. The median prevalence of dental erosion is 34.1 percent of children (interquartile range 27.4) and 31.8 percent of adults (interquartile range 18.7). In studies that reported prevalence of dental erosion in different age groups, there is a clear trend of increasing prevalence with age in children and adults.2-6 Dental erosion has been considered a common condition limited to developed countries.1 Etiology Dental erosion is caused by sustained direct contact between tooth surfaces and acidic substances. It has long been recognized that demineralization of dental enamel will occur once the oral environmental pH reaches the critical threshold of 5.5.7 Acids in the mouth originate from three main sources: produced in situ by acidogenic bacteria, ingested extrinsic acids as dietary components and dislocated intrinsic acids through the backflow of gastric contents. Acids of bacterial origin cause caries, while extrinsic and intrinsic acids cause dental erosion. Clearance of acids from the oral cavity is, to a large extent, dependent on the saliva flow rate and the saliva buffering capacity. Low saliva flow rate and poor buffering capacity allow prolonged retention of extrinsic and intrinsic acids in the mouth, which will accelerate the erosive process.