2.5 Diagnosis & Management of Tooth Wear (Erosion, Attrition, Abrasion, Abfraction)

Diagnosis & Management of Tooth Wear (Erosion, Attrition, Abrasion, Abfraction)

Non-carious tooth surface loss (tooth wear) is increasingly prevalent in modern Australian dental practice. Pathological tooth wear impairs aesthetics, reduces masticatory function, causes dentine hypersensitivity, and can compromise pulpal vitality. Successful management requires accurate diagnosis of underlying etiologies, preventive stabilization, and conservative adhesive restorative intervention.

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Differential Diagnosis of Tooth Wear Etiologies

Pathological wear rarely occurs in isolation; it is most frequently a multifactorial combination of chemical dissolution and mechanical friction.

1. Dental Erosion (Corrosion)

Chemical loss of tooth substance brought about by non-bacterial acid dissolution.

• Critical pH: Enamel dissolves at $pH < 5.5$; dentine dissolves at $pH < 6.5$.
• Intrinsic Sources: Gastric acid ($pH\ 1.0--2.0$) from Gastroesophageal Reflux Disease (GERD), bulimia nervosa, morning sickness, or chronic alcoholism.
  • Clinical Presentation: Smooth, silky, dull loss of enamel detail on palatal surfaces of maxillary anterior teeth and occlusal cupping of posterior molar cusps, leaving existing amalgam restorations standing proud above adjacent tooth structure ("amalgam islands").
• Extrinsic Sources: Dietary acid intake (citrus fruits, carbonated soft drinks, sports drinks, wine, kombucha, acid dietary supplements) or occupational exposure (battery factory workers, competitive swimmers in improperly chlorinated pools).
  • Clinical Presentation: Broad, shallow erosive lesions on facial and labial surfaces of anterior teeth and occlusal surfaces of premolars/molars.

2. Attrition

Mechanical wear of tooth structure resulting from tooth-to-tooth contact during mastication or parafunctional habits (bruxism, clenching).

• Clinical Presentation: Flat, highly polished wear facets on incisal edges and occlusal cusps that match perfectly in eccentric mandibular excursions with opposing teeth. Surrounding enamel margins are sharp and well-defined. Accompanied by hypertrophy of masseter muscles, tongue scalloping, and buccal mucosal ridging.

3. Abrasion

Physical wear of tooth substance produced by friction from foreign objects or abrasive substances repeatedly introduced into the oral cavity.

• Etiology: Over-aggressive toothbrushing with hard bristles, abrasive dentifrices, horizontal brushing technique, holding bobby pins or nails between teeth, pipe smoking, or fingernail biting.
• Clinical Presentation: V-shaped or wedge-shaped notches located at the cementoenamel junction (CEJ) on facial/buccal surfaces. The cavity walls are hard, smooth, and highly polished.

4. Abfraction

Microstructural loss of tooth substance in cervical regions hypothesized to result from flexural stress concentration during heavy eccentric occlusal loading.

• Biomechanics: Tensile and compressive forces cause tooth bending, concentrating flexural strain at the fulcrum (cervical CEJ region). This breaks the micro-chemical bonds between enamel prisms and dentine crystals, predisposing the area to accelerated loss.
• Clinical Presentation: Deep, narrow, wedge-shaped cervical lesions with sharp internal and external angles, often located on single teeth subjected to lateral occlusal interference.

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Differential Diagnosis Matrix

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Diagnostic Indices & VDO Assessment

Basic Erosive Wear Examination (BEWE)

The BEWE is a standardized scoring system that evaluates the cumulative severity of erosive wear across six oral sextants:

• Score 0: No erosive wear.
• Score 1: Initial loss of surface texture.
• Score 2: Distinct defect; hard tissue loss $<50%$ of surface area.
• Score 3: Hard tissue loss $\ge 50%$ of surface area.
• Cumulative Score Risk Levels: Low ($\le 2$), Medium (3–8), High (9–13), Severe ($\ge 14$). Directs clinical intervention guidelines.

Evaluation of Vertical Dimension of Occlusion (VDO)

Determining whether tooth wear is compensated or uncompensated dictates restorative complexity:

• Compensated Wear: Slow, progressive wear accompanied by continuous dentoalveolar eruption and alveolar bone remodeling. The Vertical Dimension of Occlusion (VDO) remains normal, but interarch vertical space for restorative material is lost.
• Uncompensated Wear: Rapid wear exceeding the rate of dentoalveolar eruption. Results in loss of VDO, reduced lower facial height, increased freeway space ($>4\text{ mm}$), and angular cheilitis.
• Assessment Methods: Measuring Freeway Space (Rest Position VDR minus Occlusal Position VDO; normal is 2–4 mm), evaluating phonetics (closest speaking space during "S" sounds), and facial aesthetics.

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Preventive & Medical Management

1. Etiology Elimination:
   • Medical referral for GERD, bulimia, or eating disorders.
   • Dietary modification: Eliminate acidic beverages between meals; use a straw; consume milk or cheese to neutralize acid.
2. Post-Erosion Hygiene Protocol:
   • Patients must NOT brush their teeth immediately after an acid reflux or vomiting episode (enamel is softened and easily abraded).
   • Rinse immediately with water, fluoridated mouthwash, or a sodium bicarbonate solution (1 tsp baking soda in water) to neutralize intraoral pH.
   • Delay toothbrushing for at least 30 to 60 minutes.
3. Desensitization & Remineralization:
   • Topical 5,000 ppm NaF toothpaste and daily application of CPP-ACP (Tooth Mousse).
4. Occlusal Protection:
   • Fabrication of a hard acrylic full-coverage nocturnal occlusal splint (Michigan / Tanner splint) to protect restorations and teeth from bruxism.

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Restorative Management & The Dahl Principle

When localized wear affects anterior teeth without sufficient interarch clearance, traditional crown preparations require destructive crown lengthening or endodontic therapy. The Dahl Principle provides a conservative alternative.

The Dahl Principle Technique

1. Adhesive Restorations in Hyper-Occlusion: Direct resin composite (or indirect ceramic/composite build-ups) are placed on the worn anterior teeth at an increased VDO, creating a localized anterior occlusal contact and intentionally opening the posterior bite by 1.0 to 2.0 mm (posterior open bite).
2. Dentoalveolar Adaptation: Over a period of 4 to 6 months, physiological compensation occurs: posterior teeth undergo axial eruption (dentine/bone movement) while anterior teeth undergo slight intrusion (PDL reconditioning).
3. Occlusal Re-establishment: Full stable posterior occlusal contacts re-establish spontaneously in $>95%$ of patients without adverse TMJ symptoms, restoring aesthetics and VDO conservatively.