Introduction

Dental erosion is defined as irreversible loss of dental hard tissue by a chemical process that does not involve bacteria.1,2  Dissolution of mineralized tooth structure occurs upon contact with acids that are introduced into the oral cavity from intrinsic (e.g., gastroesophageal reflux, vomiting) or extrinsic sources (e.g., acidic beverages, citrus fruits).  This form of tooth surface loss is part of a larger picture of tooth wear, which also consists of attrition, abrasion, and possibly, abfraction.  Table 1 lists the definitions of each of these forms of tooth surface loss or tooth wear.

Table 1.  Definitions of Tooth Surface Loss*

Tooth Wear *
Term Definition Clinical Appearance
Erosion

(Figures 1-4)

 Progressive loss of hard dental tissue by chemical processes not involving bacterial action
  • Broad concavities within smooth surface enamel
  • Cupping of occlusal surfaces, (incisal grooving) with dentin exposure
  • Increased incisal translucency
  • Wear on non-occluding surfaces
  • "Raised" amalgam restorations
  • Clean, non-tarnished appearance of amalgams
  • Loss of surface characteristics of enamel in young children
  • Preservation of enamel "cuff" in gingival crevice is common
  • Hypersensitivity
  • Pulp exposure in deciduous teeth
Attrition

(Figure 5)

 Loss by wear of surface of tooth or restoration caused by tooth to tooth contact during mastication or parafunction
  • Matching wear on occluding surfaces
  • Shiny facets on amalgam contacts
  • Enamel and dentin wear at the same rate
  • Possible fracture of cusps or restorations
Abrasion

(Figure 6)

 Loss by wear of dental tissue  caused by abrasion by foreign substance (e.g., toothbrush, dentifrice)
  • Usually located at cervical areas of teeth
  • Lesions are more wide than deep
  • Premolars and cuspids are commonly affected
Abfraction

(Figure 5)

Loss of tooth surface at the cervical areas of teeth caused by tensile and compressive forces during tooth flexure

(Studies needed to prove this hypothetical phenomenon)
  • Affects buccal/labial cervical areas of teeth
  • Deep, narrow V-shaped notch
  • Commonly affects single teeth with excursive interferences or eccentric occlusal loads
* Adapted from: Milosevic, 19983

Figures 1-6 illustrate examples of each type.  However, inasmuch as these definitions relate to different causes, it is important to recognize that each of these types of tooth wear rarely occur alone in a given individual.  A patient with generalized tooth wear may be diagnosed as being a bruxer or a heavy-handed toothbrusher, without recognition of an erosive component to the problem (Figure 7).  This has made epidemiological and clinical research in the area of tooth wear difficult.  Likewise, the diagnosis and management of patients with tooth erosion remains a challenging task.

Figure 1.  This 14-year-old female exhibits total loss of surface characteristics and polished appearance of enamel on her maxillary incisors. The enamel layer was also very thin.
Figure 2.  The fissure sealant in this 14-year-old boy stands "raised" from surrounding eroded occlusal enamel.
Figure 3.  Gastroesophageal reflux disease (GERD) was discovered in this 19 year old boy who exhibited early, generalized erosion (arrow A).  Note the preservation of the enamel at the gingival crevice (arrow B).
Figure 4.  This 33-year-old male with GERD had severe asymptomatic erosion.  Note the amalgams "rising" above the adjacent eroded occlusal surfaces.
Figure 5.  This patient's canines and bicuspids have characteristics that can be attributed to both abrasion and abfraction.  He had a bruxism habit and a tendency to brush his teeth vigorously.  Slight recession of the gingiva and cemento-enamel wear is present in a well-delineated lesion of abrasion on a prominent root (arrow).  Note the loss of the top layer of gold foil in tooth #5, suggesting possible cervical flexure forces during bruxing.  Occlusal surface loss is characteristic of attrition.  
Figure 6.  This 42-year old female has a bruxism habit and no other known risk factors for erosion, demonstrating moderate to severe attrition.
Figure 7.  Two years of continual consumption of canned citrus drinks in a hot country during Peace Corps service led to this erosion of the cervical areas of the posterior teeth. This 33-year old patient also had a bruxism habit which has contributed to occlusal attrition.
Figure 8.  Restoration of eroded teeth in this patient will require crown lengthening procedures and full coverage restorations.

Erosion is often not recognized in its early stages nor are risk factors identified and addressed. Lack of awareness of the multifactorial nature of tooth wear may lead to only partial treatment of the problem (e.g., an occlusal splint).  Partial treatment may eventually result in the necessity of complex and expensive restorative care (Figure 8).  Since early recognition and initiation of preventive measures can prevent significant damage to the dentition, dental erosion warrants the careful attention of the primary dental care team.

A review of the literature on dental erosion indicates a relatively recent, growing interest in the topic, particularly in Europe.  For the first time, England included the evaluation of tooth erosion in its national dental health survey in 1993, indicating the importance of this dental problem.4  The aim of this article is to review the etiologies of dental erosion and provide recommendations for diagnosis and management of this problem.
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