Dental Attrition

Regressive Alterations of Teeth

Attrition

• Physiologic wearing away of tooth substance due to tooth-to-tooth contact during mastication
• Most common cause: bruxism
• Clinical features:
  • Initial stage: small polished facet in cusp tips or ridges, flattening of incisal edges
  • Middle stage: gradual reduction of cusp height, flattening of occlusal inclined planes, shortening of dental arch
  • Advanced stage: wearing away of all enamel thickness, loss of intercuspal digitations, teeth may be worn down to the gingiva

Abrasion

• Pathologic wearing away of tooth substance through abnormal mechanical processes
• Etiology:
  • Incorrect use of a toothbrush
  • Use of abrasive dentifrice
• Clinical features:
  • Enamel and dentin worn away to produce a 'V' shaped notch at the neck of the tooth
  • Areas most affected: labial and buccal surfaces of canines and premolars

Abfraction

• Pathological loss of enamel and dentin due to occlusal stresses
• Etiology:
  • Occlusal forces causing the tooth to flex, leading to small enamel flecks breaking off
• Clinical features:
  • Usually wedge-shaped lesions with sharp angles found at the cervical margins
• Differential diagnosis:
  • Abrasion: abfraction has sharp angles, unlike abrasion

Erosion

• Loss of tooth substance by non-bacterial chemical processes
• Plaque is not involved in the process
• Clinical features:
  • Shallow, broad, smooth, scooped-out depression on the enamel surface near the cemento-enamel junction
  • Mostly affects the cervical third of facial surfaces of teeth, with lingual surfaces affected if the cause is internal acid source

Dentinal Sclerosis

• Calcification or deposition of calcium ion in dentinal tubules of primary dentine
• Sclerosis decreases conductivity of dentine and slows advancing carious process

Secondary Dentin

• Dentin formed after root completion
• Two types:
  • Physiologic or regular type:
    • Due to aging process
  • Pathologic or irregular type (Reparative Dentin):
    • Due to caries, attrition, abrasion, erosion, tooth fracture, and cavity preparation
• Histopathological features:
  • Physiologic secondary dentin: fewer tubules, similar in appearance to primary dentin
  • Reparative secondary dentin: few tubules, tortuous in appearance

Resorption of Teeth

• Physiologic form: shedding of deciduous teeth
• Pathologic form:
  • External resorption: on the external surface of the root
  • Internal resorption (Pink Spot): on the wall of the root canal
• Clinical features:
  • No early clinical symptoms
  • Crown: pink-hued area
  • Root: no symptoms until fracture
  • Mostly single tooth, rarely multiple teeth
• Histopathological features:
  • Variable degree of resorption of the inner or pulpal surface of the dentin
  • Proliferation of the pulp tissue filling the defect
  • Chronic inflammatory reaction in the pulp tissue