Distinguishing Erosion from Attrition and Abrasion
Erosion specifically refers to irreversible loss of hard dental tissue through chemical dissolution, distinct from mechanical wear. Patients often use the term "wear" generically, but dental professionals must distinguish three processes to guide treatment:
Erosion is chemical dissolution from intrinsic (gastric acid, bulimia, regurgitation) or extrinsic (dietary acids, occupational acid exposure) acid sources. Erosion affects smooth surfaces preferentially, creates concave "cupped" surfaces, and spares cervical areas in many cases. The margin between affected and unaffected tissue is gradual. Attrition is mechanical wear from tooth-to-tooth contact (grinding, clenching, or severe malocclusion). Attrition affects occlusal and incisal surfaces bilaterally, creates flat worn facets, and is often accompanied by muscle tenderness or jaw pain. Facets have distinct, sharp margins. Abrasion is mechanical trauma from external sources (aggressive toothbrushing, occupational acid/particle exposure, oral self-injurious habits). Abrasion typically affects cervical/gingival areas, creates V-shaped notches, and correlates with location of trauma source.In practice, patients frequently display combined patterns—erosion from dietary acids plus attrition from grinding, requiring multi-factorial management. Clinical diagnosis requires identifying all contributing factors through history and careful visual examination.
Acidic Food pH Values and Classification
Citrus Fruits and Juices: Lemon (pH 2.0-2.2) is the most acidic common food. Lime (pH 2.0-2.3) is similarly acidic. Grapefruit (pH 2.9-3.3) is less acidic than lemon but still substantially below the critical pH of 5.5. Orange (pH 3.5-4.0) and mandarin oranges (pH 3.5) are less acidic than other citrus. Interestingly, ripe oranges are slightly less acidic than underripe, but differences are modest. Tomato Products: Fresh tomato has pH 4.3-4.9, falling just below the critical erosion pH (5.5). Tomato paste concentrates the acid—pH 3.5-4.0—making it substantially more erosive than fresh tomato. Acidified tomato products (with added vinegar for preservation) can reach pH 2.5-3.0. Vinegar-Based Foods: Vinegar maintains pH 2.4-3.5 depending on concentration. Any vinegar-containing food (pickles, pickled vegetables, salad dressings with vinegar, fermented products) introduces substantial acid exposure. A single serving of pickles or vinegar-based salad can lower oral pH into the demineralization range. Fermented Foods and Beverages: Kombucha (pH 2.5-3.0), fermented beverages with added acids, and products like kimchi provide variable acid content depending on formulation. Many health-marketed fermented products achieve low pH through added citric acid or acetic acid to ensure safety, making them potentially erosive despite perceived health benefits. Wine and Beer: As discussed previously, red wine (pH 3.0-3.5) and white wine (pH 2.8-3.7) are acidic. Beer maintains pH 3.5-5.5 depending on style and acid content. Craft beers with citrus additives can be substantially more acidic. Berries and Other Fruits: While fruits are nutritious, some carry erosion risk. Strawberries (pH 3.0-3.5), raspberries (pH 3.2-3.5), and blackberries (pH 3.5-4.0) are acidic. Grapes and melons (pH 5.0-7.0) are less problematic. Dried fruits (raisins, dried cranberries) concentrate sugars but pH is variable.Intrinsic vs. Extrinsic Acid Sources
Intrinsic acids originate from the gastrointestinal tract: gastric reflux (gastric acid pH 1.0-2.0), bulimia nervosa (repeated vomiting), regurgitation from hiatal hernia, and alcoholism-related vomiting. Intrinsic acid erosion shows a characteristic palatal distribution (regurgitated acid pools on palatal surfaces during supine position) and affects lingual surfaces of mandibular teeth. These sources are beyond dietary control and require medical intervention. Extrinsic acids originate outside the body: dietary acids (foods, beverages, supplements), occupational acids (battery manufacturers, fruit processing workers exposed to acid mists), and environmental acids (chlorine swimmers with low pH pool water). Extrinsic erosion is partially preventable through dietary modification and protective strategies.Patients presenting with erosion require careful history to determine whether intrinsic (medical) or extrinsic (dietary) factors predominate. Combined patterns are common—a patient with GERD-related intrinsic erosion who also consumes frequent acidic beverages experiences compounded erosion risk.
BEWE Scoring System and Erosion Diagnosis
The Basic Erosive Wear Examination (BEWE) is the standard clinical scoring system for assessing erosion severity. Originally developed by Bartlett et al. (2008), BEWE evaluates the facial, lingual, and occlusal surfaces of buccal segments (first molars and premolars) bilaterally:
- Score 0: No erosion (normal surface characteristics intact)
- Score 1: Initial loss of surface texture; cuspal/incisal edges less sharp
- Score 2: Distinct concavity or flattening of occlusal surface; dentinal cuspids visible; dentin discoloration evident
- Score 3: Complete loss of enamel; substantial dentin exposure >1/3 of surface
- Score 0-2: No erosion requiring intervention; standard preventive advice
- Score 3-8: Mild erosion; dietary counseling and topical fluoride
- Score 9-16: Moderate erosion; detailed dietary modification, home fluoride gel, possible bonded resin restorations
- Score >16: Severe erosion; consider restorative rehabilitation, possible orthodontics to expose less-affected surfaces
Saliva's Protective Role and Buffering Capacity
Saliva protects teeth through multiple mechanisms: (1) buffering capacity—bicarbonate and phosphate ions neutralize acids; (2) pellicle formation—a proteinaceous film that slows mineral dissolution; (3) salivary antimicrobials—preventing secondary infections; and (4) remineralization—calcium and phosphate ions promote repair of demineralized enamel.
Salivary buffering capacity varies significantly among individuals (pH buffering rate 0.5-2.5 pH units/minute). Patients with low buffering capacity (slow pH recovery) are at higher erosion risk from dietary acids because their saliva cannot neutralize dietary acids quickly. Salivary flow rate also varies—hyposalivic patients (flow <0.5 mL/minute) have reduced protective capacity and warrant aggressive preventive intervention.
Testing buffering capacity and flow rate can identify high-risk patients. Patients with low buffering or flow benefit from more aggressive fluoride protocols and dietary modification.
Remineralization Strategies: Fluoride and Calcium Phosphate Products
Topical Fluoride Application: Fluoride converts hydroxyapatite to more acid-resistant fluorapatite, increasing enamel resistance to dissolution 10-50 fold. Professional 22,600 ppm sodium fluoride varnish (Duraphat) applied monthly provides rapid remineralization but is limited by toxicity concerns precluding daily application. Home-use 5,000 ppm fluoride gel in custom trays 5-10 minutes daily offers superior cumulative protection for chronic acid exposure patients.For patients unwilling to use trays, 1,450 ppm fluoride toothpaste (twice-daily brushing) provides modest remineralization but is insufficient alone for moderate-to-severe erosion. High-fluoride toothpaste (5,000 ppm) is available in some jurisdictions and should be recommended when standard toothpaste proves inadequate.
Hydroxyapatite Toothpaste: Natural hydroxyapatite toothpaste (with nano-hydroxyapatite particles) promotes remineralization through direct mineral replacement. Studies show hydroxyapatite and fluoride toothpastes are similarly effective for erosion prevention. Some patients prefer hydroxyapatite due to natural origin perception, though efficacy differences are minimal. Calcium Phosphate Systems (CPP-ACP): Casein phosphopeptide-amorphous calcium phosphate (Tooth Mousse, Tooth Mousse Plus) delivers bioavailable calcium and phosphate ions. Applied as a topical cream 5 minutes daily, CPP-ACP shows modest remineralization benefits in studies. The addition of fluoride (Tooth Mousse Plus) increases efficacy. CPP-ACP is useful for fluoride-sensitive patients or as adjunctive therapy alongside fluoride. pH-Neutral Formulations: For acid-sensitive patients, neutral pH formulations (sodium bicarbonate toothpaste, pH-neutral fluoride) are sometimes recommended, though acidity of toothpaste formulation is less critical than frequency and duration of fluoride/mineral contact.Dietary Counseling Framework and Patient Education
Effective erosion prevention requires systematic dietary assessment and counseling:
Assessment Phase: Document frequency (daily? every meal? occasional?) and timing (meals or between-meals?) of acidic food/beverage consumption. Ask about occupational or recreational acid exposure (athletes using sports drinks during competition; workers exposed to industrial fumes). Assess for intrinsic acid sources through medical history screening. Patient Education: Explain the mechanism—acid dissolves enamel (concrete, not abstract explanations improve compliance). Show BEWE photos demonstrating progression from mild to severe erosion, motivating behavior change. Discuss specific dietary modifications: substituting water for acidic beverages, consuming acidic foods with meals rather than between-meals, limiting frequency of acid exposure. Practical Recommendations: Rather than eliminating foods entirely (unrealistic, reduces quality of life), suggest strategies:- Citrus fruit consumption during meals (saliva increases during meals, providing buffering)
- Limiting citrus juice to one 4-6 oz serving daily with meals
- Using a straw for acidic beverages, positioned posteriorly
- Rinsing mouth with water after acidic exposure
- Waiting 30 minutes before brushing after acid consumption
- Chewing sugar-free gum for 20 minutes post-acid exposure to stimulate saliva flow
Summary
Acidic foods and beverages create enamel erosion risk through chemical dissolution when pH falls below 5.5—a threshold met by most citrus fruits (pH 2.0-4.0), tomato products (pH 3.5-4.9), vinegar-based foods, and many fermented beverages. BEWE scoring systematically assesses erosion severity and guides intervention selection. Erosion prevention requires distinguishing chemical erosion from mechanical attrition/abrasion through careful clinical and historical assessment. Dietary counseling focusing on consumption frequency rather than elimination, consumption timing (with meals providing saliva buffering), and behavioral strategies (straw use, delayed brushing) combined with topical fluoride and calcium phosphate remineralization is most effective. For erosion-prone individuals, tailored remineralization protocols using 5,000 ppm fluoride gel daily provides substantial protection against progressive enamel loss.