Tooth Wear may be defined as the surface loss of dental hard tissues other than by caries or trauma, and it is a natural consequence of ageing. Components of tooth wear • Erosion • Attrition • Abrasion Erosion • is defined as the loss of dental hard tissue as a result of a chemical process not involving bacteria. • The causative agent is usually acid. What are the sources of acid? Extrinsic Acids 1. Dietary including : • foods such as citrus fruits, pickles and other items containing vinegar. • Carbonated and acid-containing drinks. • Acidic medications is occasionally implicated. • Occupational and recreational acids. Extrinsic Acids Intrinsic acids 2. Stomach acids associated with: • anorexia nervosa • Hiatus hernia • Peptic ulcers • Pregnancy with prolonged morning sickness • Digestive disturbances which cause recurrent vomiting Clinical features of Erosion • 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 Clinical features of Erosion • 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 Erosion • 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. Erosion • 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). Cuff of enamel • Blue arrow indicates a cuff of enamel. Erosion • The fissure sealant in this 14-year-old boy stands "raised" from surrounding eroded occlusal enamel. Erosion • This 33-year-old male with GERD had severe asymptomatic erosion. Note the raised amalgams "rising" above the adjacent eroded occlusal surfaces. Erosion due to soft drinks • erosion of the left side mandibular molars of a 20-year old female who habitually enjoyed holding a cola beverage in this area for several minutes before swallowing. Other parts of the dentition were not affected. Erosion • Two years of continual consumption of canned citrus drinks in a hot country led to this erosion of the cervical areas of the posterior teeth. Erosion • Restoration of eroded teeth in this patient will require crown lengthening procedures and full coverage restorations. erosion • Extreme example of tooth erosion in patient who suffered repeated gastric regurgitation Attrition Attrition: is the mechanical Loss of tooth surface or restoration caused by tooth to tooth contact during mastication or parafunction. Clinical features of attrition – Shiny facets on amalgam contacts – Enamel and dentin wear at the same rate – Possible fracture of cusps or restorations Attrition • This 42-year old female has a bruxism habit and no other known risk factors for erosion, demonstrating moderate to severe attrition. Attrition in eccentric occlusion Cusp facets Abrasion • Abrasion is the wearing away of tooth substance by mechanical means other than by opposing teeth, such as over- vigorous tooth-brushing or holding pipe. Clinical features of abrasion – Usually located at cervical areas of teeth – Lesions are more wide than deep – Premolars and cuspids are commonly affected abrasion • Pipe smoking abrasion • Nail biting Abrasion / vigorous tooth brushing abfraction • 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) Clinical features of abfraction • Affects buccal / labial cervical areas of teeth • Deep, narrow V-shaped notch • Commonly affects single teeth with excursive interferences or eccentric occlusal loads Abrasion and abfraction • This patient's canines and bicuspids have characteristics that can be attributed to both abrasion and abfraction. Diagnosis and monitoring of tooth wear • View teeth clean and dry • Take study models at six months interval to determine the rate of progress. • Take sympathetic history to elicit the cause. • The history might include: Taking history for Erosion • Past and present diet • Digestive disorders • Past and present slimming habits • Alcohol intake • Is the patient under any medications? • Occupation. Taking history for Attrition & abrasion • Clenching and grinding habits • Periods of stress or anxiety • Square face? Or over developed muscles? • Pipe smoking, opening hairgrips…etc Preventing tooth wear • Diminish the frequency and severity of the acid challenge. • Enhance the defence mechanisms of the body (increase salivary flow and pellicle formation). • Enhance acid resistance, remineralization of the tooth surfaces. • Decrease abrasive forces. • Provide mechanical protection. BRA. • Monitor stability ( casts and recall visits) When are restorations necessary? • A. Patient decision: – patient’s appearance – tooth becomes sensitive • B. Dentist’s decision: – Decrease in occlusal vertical dimension – Pulp exposure – In advance cases crowns are required.